New Technology and Techniques in the Treatment of Foot and Ankle Injuries

  • David J. Soomekh
    Affiliations
    University Foot and Ankle Institute, 2121 Wilshire Boulevard Suite 101, Santa Monica, CA 90403, USA

    Department of Surgery, University of California Los Angeles Medical Center, 17th Street, Los Angeles, CA 90404, USA

    Department of Surgery, Cedars-Sinai Medical Center, Beverly Hills, Beverly Boulevard, CA 90048, USA
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      Keywords

      The advancement of new technologies in the treatment of foot and ankle injuries seems exponential over the last several years. As surgeons expand their knowledge of pathology and improve their treatment techniques, they come upon new and different ways to treat the same pathologic conditions. However, the surgeons know that there is always a drive to perfect technique and decrease morbidity and recovery time. Therefore, there are always new and improved techniques and devices to investigate.

      Subtle Lisfranc dislocation

       Anatomy

      The stability of the tarsometatarsal (TMT) joint is based on the configuration of the bases of the metatarsals and the cuneiforms and the ligaments that joint them. The TMT joint includes the first, second, and third metatarsals and their corresponding cuneiforms. The metatarsals are joined together by the transverse dorsal and plantar ligaments. The second metatarsal is wedged as a keystone between the medial and lateral cuneiforms, whereas the plantar ligaments stabilize it to the midfoot.
      • Cunningham D.J.
      • Romanes G.J.
      Cunningham’s textbook of anatomy.
      The dorsal and plantar ligaments are oriented longitudinally, obliquely, and transversely. The oblique and longitudinal fibers connect the cuneiforms to the proximal aspect of the metatarsals, whereas the transverse fibers are between the bases of the metatarsals. The strongest of the interosseous ligaments that stabilizes the first and second metatarsals is often named as the Lisfranc ligament.
      • Coetzee J.C.
      Making sense of Lisfranc injuries.
      This ligament is located between the medial cuneiform and the base of the second metatarsal.

       Injury

      A sprain of the midfoot is a common injury in athletes.
      • DeOrio M.
      • Erickson M.
      • Usuelli F.G.
      • et al.
      Lisfranc injuries in sport.
      The sprain can occur when the foot is placed in a plantar flexed and rotated position when an indirect longitudinal force is applied followed by a forceful abduction. The angle and the intensity of this force determines the degree of injury, whether it is a fracture or ligamentous pathology.
      • Coetzee J.C.
      Making sense of Lisfranc injuries.
      It is thought that a torsional force is applied to the midfoot that then unlocks the second metatarsal. This injury is most common in soccer, football, gymnastics, basketball, baseball, ballet, and running. This article presents a discussion of a more subtle dislocation.
      Many classification systems have been derived at to describe the level of injury to the ligaments and associated fractures. Hardcastle and colleagues
      • Hardcastle P.H.
      • Reschauer R.
      • Kutscha-Lissberg E.
      • et al.
      Injuries to the tarsometatarsal joint. Incidence, classification and treatment.
      based their classification system on the shift of the midfoot in the transverse plane: type A for total incongruity, type B for partial incongruity, and type C for divergent incongruity. Myerson and colleagues
      • Myerson M.S.
      • Fisher R.T.
      • Burgess A.R.
      • et al.
      Fracture dislocations of the tarsometatarsal joints: end results correlated with pathology and treatment.
      expanded on this system by including subdivisions to the Hardcastle system, ie, B1, B2, C1, and C2, depending on the complexity of the injury.
      It was Nunley and Vertullo
      • Nunley J.A.
      • Vertullo C.J.
      Classification, investigation, and management of midfoot sprains: Lisfranc injuries in the athlete.
      who presented a classification system for the more subtle injuries from low-impact injuries that are seen in athletes. This system addresses the more-ligamentous injuries to the joint with a possible fleck avulsion fracture. Stage I represents a sprain of the Lisfranc ligament without a measurable diastasis between the base of the second metatarsal and the medial cuneiform or any loss of arch height on weight-bearing radiographs. There is then no measured instability of the Lisfranc joint. Stage II represents a sprain of the ligament with a diastasis of 1 to 5 mm between the base of the second metatarsal and the medial cuneiform. There is still no loss of arch height, but both the dorsal and interosseous ligaments are injured, and the plantar structures are intact. In a stage III injury, there is a diastasis of greater than 5 mm and a loss of arch height.
      • Nunley J.A.
      • Vertullo C.J.
      Classification, investigation, and management of midfoot sprains: Lisfranc injuries in the athlete.

       Diagnosis

      When there is a high suspicion for a midfoot sprain, a detailed history and clinical examination can help to confirm the evidence of the injury. The patient usually presents with pain along the first and second rays, with pinpoint palpation pain within the interspace between the bases of the first and second metatarsals and the medial cuneiform. There is often pain in this area with simultaneous medial and lateral compression of the midfoot. The experienced clinician may also appreciate the instability of the medial complex through sagittal and transverse plane range of motions. Weight-bearing radiographic imaging should be used to determine the degree of injury, including stress views. In those cases in which there is a suspicion on plain films, magnetic resonance imaging (MRI) or computed tomography (CT) could be helpful in the final diagnosis of the severity of the sprain (Fig. 1).
      Figure thumbnail gr1
      Fig. 1Isolated Lisfranc rupture dislocation.

       Treatment

      It is well documented that Lisfranc injuries, whether low- or high-grade, must be treated aggressively. There are many reports that early and proper treatment and anatomic reduction leads to better functional results and a reduction in future instability and osteoarthritis.
      • Aitken A.P.
      • Poulson D.
      Dislocations of the tarsometatarsal joint.
      • Bassett 3rd, F.H.
      Dislocations of the tarsometatarsal joints.
      • Granberry W.M.
      • Lipscomb P.R.
      Dislocation of the tarsometatarsal joints.
      • Hesp W.L.
      • van der Werken C.
      • Goris R.J.
      Lisfranc dislocations: fractures and/or dislocations through the tarso-metatarsal joints.
      • Wilson D.W.
      Injuries of the tarso-metatarsal joints. Etiology, classification and results of treatment.
      Conservative treatments are reserved for those injuries that are classified as Nunley and Vertullo stage I injuries. Treatment includes a period of guarded weight bearing in a pneumatic walker or a non–weight-bearing cast for 6 weeks. Stress views can be reevaluated to determine if a longer course of non–weight-bearing is indicated. Progressive weight bearing in custom-molded orthotics with physical therapy is recommended for up to 3 months, depending on the severity of the injury.
      Nunley and Vertullo stage II and stage III injuries should be treated with open reduction and internal fixation (ORIF). It is important to maintain the stability of the second metatarsal. Traditionally, stability has been achieved with a partially threaded cannulated 3.5-, 4.0-, or 4.5-mm screw. The fixation is placed in a proximal-medial to distal-lateral direction through the central medial aspect of the medial cuneiform into the base of the second metatarsal. There are inherent problems with this type of fixation. The screw needs to be removed after full recovery. This removal requires another surgical setting, with its own inherent risks and complications. It also results in additional recovery time while the void left by the screw fills in. It can be difficult to gain adequate compression with the screw because it does not cross the cortex of the second metatarsal. Attempted compression could cause fracture or pull-out of the screw. Furthermore, there could be disruption of the cartilaginous surfaces by the screw.
      In vivo studies have shown that complete immobilization of a ligament could be harmful to its healing and may reduce its mechanical properties.
      • Hart D.P.
      • Dahners L.E.
      Healing of the medial collateral ligament in rats. The effects of repair, motion, and secondary stabilizing ligaments.
      • Walsh S.
      • Frank C.
      • Shrive N.
      • et al.
      Knee immobilization inhibits biomechanical maturation of the rabbit medial collateral ligament.
      This finding indicates that a fixation that could facilitate the dynamic properties of the ligament during healing would be ideal. One way to achieve such a fixation is with the use of a combination suture and button fixation system. The author prefers to use a suture-endobutton combination for fixation to stabilize a stage II or stage III dislocation. The Mini TightRope system (Arthrex, Inc, Naples, FL, USA) is most often used (Fig. 2). The TightRope construct is made up of 2 metal buttons connected to one another by 4 strands of No. 2 FiberWire (Arthrex, Inc, Naples, FL, USA). This construct allows for strength from the 4 strands of FiberWire and flexibility that is not achieved by screw fixation. The TightRope is used in the same manner as a screw. However, the advantages of using the TightRope are that removal is not needed, compression can be achieved, dynamic motion of the ligament is restored, and the suture can act as the ligament if the ligament fails to heal. Panchbhavi and colleagues
      • Panchbhavi V.K.
      • Vallurupalli S.
      • Yang J.
      • et al.
      Screw fixation compared with suture-button fixation of isolated Lisfranc ligament injuries.
      compared the stability provided by a suture-button fixation system with that of the traditional screw fixation for simple diastases of Lisfranc ligament. They used cadaveric specimens with isolated Lisfranc ligament transections, placed the fixation, and applied a 35-kg load. They showed that when a load is applied, the difference between displacement before and after screw fixation and suture-button fixation is significant. They concluded that stabilization and reduction of the diastases using both methods were not statistically different.
      Figure thumbnail gr2
      Fig. 2Repair of Lisfranc injury with TightRope.

       Surgical Technique

      An incision is made on the medial aspect of the medial cuneiform. Blunt dissection is performed to the level of the retinaculum. The retinaculum is incised and retracted for later closure. The periosteum over the central aspect of the medial cuneiform is incised and freed with a freer elevator. A second incision is made over the dorsal lateral aspect of the second metatarsal just distal to the base. The muscle tissue and periosteum are reflected off the lateral cortex of the metatarsal. Under fluoroscopy, the guidewire from the set is used to determine the angle of the drill hole and is placed over the dorsum of the foot while obtaining an anteroposterior (AP) view. The wire should be positioned at the center of the medial cuneiform and aimed toward the second metatarsal in a proximal-medial to distal-lateral direction toward the base of the second metatarsal. The guidewire is then driven under fluoroscopic guidance through the cuneiform and out the base of the metatarsal, just exiting at the level where the second interspace is exposed between the second and third metatarsals. It is crucial to exit the center of the width of the metatarsal. Alternatively, the guide pin can be driven from the base of the second metatarsal laterally through the cuneiform medially. The cannulated drill is then placed over the guidewire and driven from medial to lateral, breaking through all 4 cortices; the drill and wire are then removed. The FiberWire with the endobuttons is introduced through the drill hole using the guide pin from the second metatarsal to the cuneiform, which leaves the round button on the lateral aspect of the metatarsal, while the oblong button is brought out from the medial aspect of the cuneiform and placed flush over the cortex. The articulation is reduced by the surgeon’s assistant with compression of the midfoot from side to side. The lateral round button is then placed flush over the cortex of the base of the second metatarsal by toggling the 2 free suture ends until the other 2 looped sutures over the button are synched tight. With the button flush over the cortex, the free suture is pulled tight and a knot is made over the button. The assistant’s reduction is released, and fluoroscopy is used to confirm that the reduction holds. When the appropriate amount of reduction is achieved, the suture is knotted several more times and then cut. The suture knot is then tucked plantarly and into the musculature to avoid irritation. Some patients have experienced irritation of the nerves in this area because of the knot. Alternatively, the suture can be passed from medial to lateral, leaving the knot on the cuneiform. However, there can be irritation in shoe gear from the large knot placed medially just below the skin. Routine closure is then performed. The foot is placed in a non–weight-bearing cast for 2 weeks and then in a non–weight-bearing pneumatic walker for another 2 to 3 weeks. Light range of motion and physical therapy is started after 2 weeks. The patient is transferred to weight bearing in the walker for another 2 to 3 weeks and then to athletic shoe gear and orthotics. Physical therapy continues with a gradual return to activity.

      Tibiofibular syndesmosis injury

      The syndesmotic ligament complex is essential to the function, stability, and support of the ankle joint. Isolated syndesmotic injuries have been shown to occur in about 1% to 18% of ankle sprains. When left untreated, the injuries can be a source of prolonged morbidity, pain, and arthritis in athletes.
      • Close J.R.
      Some applications of the functional anatomy of the ankle joint.
      • Fallat L.
      • Grimm D.J.
      • Saracco J.A.
      Sprained ankle syndrome: prevalence and analysis of 639 acute injuries.
      • Gerber J.P.
      • Williams G.N.
      • Scoville C.R.
      • et al.
      Persistent disability associated with ankle sprains: a prospective examination of an athletic population.
      • Hopkinson W.J.
      • St Pierre P.
      • Ryan J.B.
      • et al.
      Syndesmosis sprains of the ankle.
      The incidence of injury may be even higher because of the difficulty in diagnosis or missed diagnosis in the absence of frank diastasis or instability in the ankle.
      • Rammelt S.
      • Zwipp H.
      • Grass R.
      Injuries to the distal tibiofibular syndesmosis: an evidence-based approach to acute and chronic lesions.
      In athletes, the syndesmotic injury is most commonly seen in collision sports like rugby, hockey, football, lacrosse, and wrestling.
      • Nussbaum E.D.
      • Hosea T.M.
      • Sieler S.D.
      • et al.
      Prospective evaluation of syndesmotic ankle sprains without diastasis.
      • Williams G.N.
      • Jones M.H.
      • Amendola A.
      Syndesmotic ankle sprains in athletes.
      • Wright R.W.
      • Barile R.J.
      • Surprenant D.A.
      • et al.
      Ankle syndesmosis sprains in National Hockey League players.
      With the advent of stiffer ski boots that extend higher above the ankle, there has been an increased prevalence of syndesmotic injuries compared with lateral ankle sprains in skiers.
      • Fritschy D.
      An unusual ankle injury in top skiers.

       Anatomy

      The ligamentous union between the tibia and the fibula is a complex structure that can be broken down into 3 major parts: the proximal tibiofibular syndesmosis, the aponeurotic interosseous membrane (IOM), and the distal tibiofibular complex. This distal complex is the most important of the 3 and consists of 5 portions: the anterior inferior tibiofibular ligament (AITFL), the posterior inferior tibiofibular ligament (PITFL), the transverse tibiofibular ligament (TTFL), the interosseous tibiofibular ligament (IOL), and the distal portion of the aponeurotic IOM.
      • Rammelt S.
      • Zwipp H.
      • Grass R.
      Injuries to the distal tibiofibular syndesmosis: an evidence-based approach to acute and chronic lesions.
      Studies have shown that serial sectioning of the distal complex increases the tibiofibular diastasis by an average of 2.5 mm. When the entire distal complex is sectioned, a total diastasis of 7.33 mm is appreciated.
      • Ogilvie-Harris D.J.
      • Reed S.C.
      • Hedman T.P.
      Disruption of the ankle syndesmosis: biomechanical study of the ligamentous restraints.
      • Sarsam I.M.
      • Hughes S.P.
      The role of the anterior tibio-fibular ligament in talar rotation: an anatomical study.
      • Xenos J.S.
      • Hopkinson W.J.
      • Mulligan M.E.
      • et al.
      The tibiofibular syndesmosis. Evaluation of the ligamentous structures, methods of fixation, and radiographic assessment.

       Injury

      An injury to the syndesmosis can occur when there is a forced separation between the distal tibia and fibula. This seperation can happen when there is a forced external rotation of the talus in the ankle mortise. There can also be an internal rotation of the tibia at the same time. Isolated injuries to the syndesmosis without fracture are rare and can occur when there is not enough external rotational force to sustain a fracture.
      • Hopkinson W.J.
      • St Pierre P.
      • Ryan J.B.
      • et al.
      Syndesmosis sprains of the ankle.
      • Edwards Jr., G.S.
      • DeLee J.C.
      Ankle diastasis without fracture.
      • Miller C.D.
      • Shelton W.R.
      • Barrett G.R.
      • et al.
      Deltoid and syndesmosis ligament injury of the ankle without fracture.
      • Rose J.D.
      • Flanigan K.P.
      • Mlodzienski A.
      Tibiofibular diastasis without ankle fracture: a review and report of two cases.
      These injuries are often labeled as high-ankle sprains.
      Syndesmotic injuries that are associated with fractures are more common and have been detailed by Lauge-Hansen.
      • Lauge-Hansen N.
      Fractures of the ankle. II. Combined experimental-surgical and experimental-roentgenologic investigations.
      • Lauge-Hansen N.
      Fractures of the ankle. IV. Clinical use of genetic roentgen diagnosis and genetic reduction.
      When the foot is in supination and there is an external rotational force, there can be a rupture of the AITFL, an avulsion at the anterior tubercle of the tibia (Chaput), or an avulsion at the fibular insertion of the ligament (Wagstaffe). When the external rotation continues, there is a spiral fracture of the lateral malleolus. An injury with a supination and external rotation, stage I in the Lauge-Hansen
      • Lauge-Hansen N.
      Fractures of the ankle. II. Combined experimental-surgical and experimental-roentgenologic investigations.
      classification, leads to an isolated rupture of the ligament. When the foot is in pronation with external rotation, the deltoid ligament ruptures first or there is a medial malleolar fracture. With continued external rotation, the AITFL and the IOL rupture, and then there is a spiral or oblique fracture of the fibula or rupture of the IOM with a proximal fibular fracture. The PITFL and the TTFL are avulsed or ruptured in a stage IV injury. When an abduction force is applied to a pronated foot, there is a medial malleolar fracture followed by an avulsion or a rupture of the AITFL and the PITFL and elongation of the IOL and IOM. As this force continues, the fibula fractures at the level of the syndesmosis. The most unstable syndesmotic tears are sustained with a pronation-external rotation stages III and IV.
      • Lauge-Hansen N.
      Fractures of the ankle. II. Combined experimental-surgical and experimental-roentgenologic investigations.

       Diagnosis

      The clinical and radiographic examinations are critical when there is a high suspicion for a syndesmotic tear. The patient presents with pain in the anterolateral aspect of the ankle joint, which is increased with forced dorsiflexion. Pain is elicited on palpation in this area. The “squeeze test” can be applied by compression of the tibia to the fibula just above the midpoint of the calf.
      • Frick H.
      • Saunders E.A.
      Ligamentous injuries of the ankle.
      This compression elicits pain at the level of the distal tibiofibular syndesmosis. Frick test can be applied by holding the foot in a neutral position against a fixed lower leg and applying passive external rotation of the foot.
      • Frick H.
      This maneuver elicits pain over the area of the syndesmosis. The Frick test has proved to be sensitive and is more reliable than the squeeze test.
      • Beumer A.
      • Swierstra B.A.
      • Mulder P.G.
      Clinical diagnosis of syndesmotic ankle instability: evaluation of stress tests behind the curtains.
      • Boytim M.J.
      • Fischer D.A.
      • Neumann L.
      Syndesmotic ankle sprains.
      • Grass R.
      • Herzmann K.
      • Biewener A.
      • et al.
      Plain radiographic examination consists of the standard 3 views of the ankle, including a true AP and mortise view, to rule out fractures. The AP or mortise view aids in the detection of a syndesmotic tear. Proximal radiographs should be obtained to rule out proximal fibular fractures. It is also helpful to obtain contralateral views for comparison. To evaluate the radiograph for a syndesmotic tear without frank diastasis, specific measurements can be obtained. The tibiofibular clear space (ie, espace clair) described by Chaput should measure less than 6 mm, whereas the tibiofibular overlap should measure more than 6 mm and the medial clear space should measure less than 5 mm on the AP radiograph. The tibiofibular overlap should be more than 1 mm on the mortise view.
      • Clanton T.O.
      • Paul P.
      Syndesmosis injuries in athletes.
      • Gardner M.J.
      • Demetrakopoulos D.
      • Briggs S.M.
      • et al.
      Malreduction of the tibiofibular syndesmosis in ankle fractures.
      • Harper M.C.
      • Keller T.S.
      A radiographic evaluation of the tibiofibular syndesmosis.
      • Takao M.
      • Ochi M.
      • Oae K.
      • et al.
      Diagnosis of a tear of the tibiofibular syndesmosis. The role of arthroscopy of the ankle.
      • Yablon I.G.
      • Leach R.E.
      Reconstruction of malunited fractures of the lateral malleolus.
      Stress radiographs can also be used when there is still a suspicion for a tear that is latent on the regular views.
      CT scans can be useful and are more accurate than plain radiographs, mostly in cases of low diastasis that can go undetected on plain films. Bilateral images can be helpful. MRI is specific and sensitive in imaging the syndesmosis and can help determine the degree of the pathologic condition and specifically which ligaments in the complex are torn. There is no clear algorithm for radiographs to determine if surgery is indicated to repair the ligament. It is generally considered that a difference of more than 2 mm when compared with the contralateral side indicates a high suspicion of syndesmotic instability from a rupture of at least 2 or more ligaments and could lead to abnormalities of the ankle joint if not stabilized surgically.
      • Rammelt S.
      • Zwipp H.
      • Grass R.
      Injuries to the distal tibiofibular syndesmosis: an evidence-based approach to acute and chronic lesions.

       Treatment

      Syndesmotic injuries with instability and frank or latent diastasis with or without an associated malleolar fracture that are left untreated can lead to significant joint abnormalities. These injuries should be treated with operative stabilization to heal the ligaments in the correct position to maintain stability to the joint and length to the fibula. Traditionally, surgery is performed with open reduction with 1 or 2 syndesmosis screws.
      • Close J.R.
      Some applications of the functional anatomy of the ankle joint.
      • Xenos J.S.
      • Hopkinson W.J.
      • Mulligan M.E.
      • et al.
      The tibiofibular syndesmosis. Evaluation of the ligamentous structures, methods of fixation, and radiographic assessment.
      • Rose J.D.
      • Flanigan K.P.
      • Mlodzienski A.
      Tibiofibular diastasis without ankle fracture: a review and report of two cases.
      • Grass R.
      • Herzmann K.
      • Biewener A.
      • et al.
      • Burns 2nd, W.C.
      • Prakash K.
      • Adelaar R.
      • et al.
      Tibiotalar joint dynamics: indications for the syndesmotic screw–a cadaver study.
      • Ebraheim N.A.
      • Elgafy H.
      • Padanilam T.
      Syndesmotic disruption in low fibular fractures associated with deltoid ligament injury.
      • McBryde A.
      • Chiasson B.
      • Wilhelm A.
      • et al.
      Syndesmotic screw placement: a biomechanical analysis.
      • Peter R.E.
      • Harrington R.M.
      • Henley M.B.
      • et al.
      Biomechanical effects of internal fixation of the distal tibiofibular syndesmotic joint: comparison of two fixation techniques.
      • Zalavras C.
      • Thordarson D.
      Ankle syndesmotic injury.
      However, there is debate as to the size of the screws used, the number of cortices to engage, and the distance from the joint the screws should be placed.
      • Rammelt S.
      • Zwipp H.
      • Grass R.
      Injuries to the distal tibiofibular syndesmosis: an evidence-based approach to acute and chronic lesions.
      • Beumer A.
      • Campo M.M.
      • Niesing R.
      • et al.
      Screw fixation of the syndesmosis: a cadaver model comparing stainless steel and titanium screws and three and four cortical fixation.
      • Chissell H.R.
      • Jones J.
      The influence of a diastasis screw on the outcome of Weber type-C ankle fractures.
      • Moore Jr., J.A.
      • Shank J.R.
      • Morgan S.J.
      • et al.
      Syndesmosis fixation: a comparison of three and four cortices of screw fixation without hardware removal.
      • Reckling F.W.
      • McNamara G.R.
      • DeSmet A.A.
      Problems in the diagnosis and treatment of ankle injuries.
      Syndesmotic screws may have their disadvantages. There is an inherent motion during regular gait between the tibia and fibula owing to the flexibility of the ligament.
      • Close J.R.
      Some applications of the functional anatomy of the ankle joint.
      • Beumer A.
      • Valstar E.R.
      • Garling E.H.
      • et al.
      Kinematics of the distal tibiofibular syndesmosis: radiostereometry in 11 normal ankles.
      Rigid screw fixation across the ligament may interfere with the normal motion between the bones. Thornes and colleagues
      • Thornes B.
      • Shannon F.
      • Guiney A.M.
      • et al.
      Suture-button syndesmosis fixation: accelerated rehabilitation and improved outcomes.
      reported that this rigid fixation with screws, where normal movement is needed, can lead to loosening, breakage, or failure of the fixation. Traditionally, screw fixation necessitates removal of the screws later. Soin and colleagues
      • Soin S.P.
      • Knight T.A.
      • Dinah A.F.
      • et al.
      Suture-button versus screw fixation in a syndesmosis rupture model: a biomechanical comparison.
      performed a cadaveric study to compare the natural motion of the fibula with screw fixation and suture-endobutton fixation. They found that the fibular motion was similar between the 2 fixation techniques.
      The use of interosseous suture and endobuttons to manage a syndesmotic rupture has been increasingly investigated. The technique has been shown to be minimally invasive and provides a semirigid and dynamic fixation across the syndesmosis, which may allow for some of the natural motion between the tibia and fibula. This type of fixation rarely needs to be removed. Klitzman and colleagues
      • Klitzman R.
      • Zhao H.
      • Zhang L.Q.
      • et al.
      Suture-button versus screw fixation of the syndesmosis: a biomechanical analysis.
      performed a study on cadaveric specimens and found that the suture-button fixation maintained reduction when placed under the same loads as an intact syndesmosis. They also found that it allowed for more physiologic movement in the sagittal plane when compared with screw fixation. Seitz and colleagues
      • Seitz Jr., W.H.
      • Bachner E.J.
      • Abram L.J.
      • et al.
      Repair of the tibiofibular syndesmosis with a flexible implant.
      were able to use the endobutton technique successfully. Thornes and colleagues
      • Thornes B.
      • Walsh A.
      • Hislop M.
      • et al.
      Suture-endobutton fixation of ankle tibio-fibular diastasis: a cadaver study.
      showed the endobutton to be biomechanically equivalent to a 4.5-mm quadricortical screw. They also reported a decrease in the rehabilitation time.
      • Thornes B.
      • Shannon F.
      • Guiney A.M.
      • et al.
      Suture-button syndesmosis fixation: accelerated rehabilitation and improved outcomes.
      Cottom and colleagues
      • Cottom J.M.
      • Hyer C.F.
      • Philbin T.M.
      • et al.
      Transosseous fixation of the distal tibiofibular syndesmosis: comparison of an interosseous suture and endobutton to traditional screw fixation in 50 cases.
      reported a prospective study comparing 25 patients with screw fixation with 25 patients with endobutton fixation. They found no statistical difference between the 2 fixation techniques when measuring age, follow-up duration, time to postoperative weight bearing, or subjective outcomes scores. They found that most of the radiologic measurements had no statistical differences. They offer that the suture endobutton fixation is a valid option compared with traditional AO screw fixation.
      • Cottom J.M.
      • Hyer C.F.
      • Philbin T.M.
      • et al.
      Transosseous fixation of the distal tibiofibular syndesmosis: comparison of an interosseous suture and endobutton to traditional screw fixation in 50 cases.
      • Cottom J.M.
      • Hyer C.F.
      • Philbin T.M.
      • et al.
      Treatment of syndesmotic disruptions with the Arthrex TightRope: a report of 25 cases.

       Surgical Technique

      In cases in which ORIF is needed on the fibula or tibia, these procedures should be performed first using standard AO principles. The suture-button complex can be incorporated over a lateral tubular fibular plate through one of its distal holes. The author uses the Syndesmotic TightRope (Arthrex, Inc, Naples, FL, USA). The system comprises a No. 5 FiberWire looped into 4 strands with 2 endobuttons, a 3.5 × 10-mm oblong button for the medial aspect and a 6.5-mm round button for the lateral aspect. The syndesmosis is reduced using a reduction clamp. The guidewire from the set is driven from lateral to medial about 1.5 cm above the tibial plafond aiming about 30° anterior to the coronal plane exiting the medial cortex of the tibia. The cannulated 3.5-mm drill is driven over the guidewire through all 4 cortices. The drill and guidewire are removed. The nitinol needle attached to the suture is passed through the drill hole exiting percutaneously through the medial skin, with care to avoid the saphenous nerve and vein. The pull-through sutures attached to the button are pulled through the skin, bringing the oblong button out of the drill hole and over the cortex. Under fluoroscopy, the button is positioned flush over the medial cortex of the tibia by toggling the 2 pairs of No. 5 FiberWire laterally. The pull-through sutures are cut and removed off the button. The lateral round button is tightened over the lateral cortex of the fibula by pulling the free ends of the suture, with the syndesmosis reduced in internal rotation and mild ankle plantar flexion. The suture is then secured with several knots and tucked over the button to reduce its prominence. In cases of a Maisonneuve fracture or significant syndesmotic instability, a second TightRope can be placed 1 cm above the first with slight axial divergence to increase the rotational stability. Postoperative management depends on the presence of an isolated syndesmotic injury or an associated fracture.

      Achilles tendinosis and rupture

      Injuries of the Achilles tendon is commonly encountered by the foot and ankle surgeon. Injuries are most often sustained by athletes. However, it also commonly seen in people who play sports regularly. It has been associated with overuse injuries, biomechanical deformity, systemic disease, inflammatory disease, and poor training. The tendon is vital to the proper function and strength in normal gait. Acute or chronic tears or tendinosis can lead to significant loss of function, loss of strength, and pain.

       Anatomy

      The gastrocnemius muscle merges with the soleus to form the Achilles tendon. It is more round proximally and flattens distally. The tendon fiber is not vertical but rotates 90° before it broadens and inserts into the middle of the posterior calcaneal tuberosity. The tendon does not have a true synovial sheath but has a paratenon comprising a visceral and parietal layer. The tendon receives most of its vascular supply from the paratenon and secondarily from the myotendinous junction and the calcaneal insertion. Vascular studies have shown the watershed area to be about 2 to 6 cm proximal to the insertion. The Achilles tendon works as a spring, storing and releasing elastic strain and energy during gait. In vitro studies have shown the tendon to have a breaking point at about 100 MPa and that it can endure about 70 MPa during maximal eccentric plantar flexions.
      • Butler D.L.
      • Grood E.S.
      • Noyes F.R.
      • et al.
      Effects of structure and strain measurement technique on the material properties of young human tendons and fascia.
      • Komi P.V.
      • Fukashiro S.
      • Jarvinen M.
      Biomechanical loading of Achilles tendon during normal locomotion.
      • Wren T.A.
      • Yerby S.A.
      • Beaupre G.S.
      • et al.
      Mechanical properties of the human Achilles tendon.

       Tendinosis

       Injury

      Tendinosis is defined as a chronic degenerative process that lacks an adequate healing response. The tendon shows collagen degeneration, fiber disorientation, scattered vascular in-growth, and the absence of inflammation.
      • Astrom M.
      • Rausing A.
      Chronic Achilles tendinopathy. A survey of surgical and histopathologic findings.
      • Jozsa L.
      • Kannus P.
      Histopathological findings in spontaneous tendon ruptures.
      • Khan K.M.
      • Maffulli N.
      Tendinopathy: an Achilles’ heel for athletes and clinicians.
      • Leadbetter W.B.
      Cell-matrix response in tendon injury.
      • Movin T.
      • Gad A.
      • Reinholt F.P.
      • et al.
      Tendon pathology in long-standing achillodynia. Biopsy findings in 40 patients.
      Leadbetter
      • Leadbetter W.B.
      Cell-matrix response in tendon injury.
      suggested that tendinosis is a failure of the cell matrix to adapt to repetitive trauma caused by an imbalance between the degeneration and synthesis of the matrix. Tendons heal by scarring instead of by regeneration as normally seen in most tissues.
      • Jozsa L.
      • Kannus P.
      Histopathological findings in spontaneous tendon ruptures.
      • Leadbetter W.B.
      Cell-matrix response in tendon injury.
      Tendinosis of the Achilles tendon often leads to nodular formations within the substance of the tendon, which may or may not be painful. The nodules are thought to be created when there is repetitive microtearing within the tendon, leading to increased scarring and thickness.
      The causes of Achilles tendinosis or tendinopathy are still unclear. Theories include overuse, lack of vasculature, decreased flexibility, genetics, and endocrine disorders. Causes may also include tissue hypoxia and free-radical production that can cause changes in the tendon and exercise-induced hyperthermia.
      • Wilson A.M.
      • Goodship A.E.
      Exercise-induced hyperthermia as a possible mechanism for tendon degeneration.
      A tendon that has been strained repetitively to more than 4% of its original length loses elasticity and has an increased risk of break in the collagen structure.
      • Kader D.
      • Saxena A.
      • Movin T.
      • et al.
      Achilles tendinopathy: some aspects of basic science and clinical management.

       Diagnosis

      Patients present with consistent long-term pain within the tendon, which may have not responded to conservative therapies. It is important to investigate the onset and degree of pain and the aggravating factors. There should be an evaluation of the patient’s activities that may be associated with the pathologic condition. The pain is usually located anywhere between 2 and 6 cm proximal to the calcaneal insertion. Some patients present with pain during normal walking, whereas others relate pain only when exercising. Most patients do not have pain at rest.
      Clinical examination includes a full lower-extremity evaluation of both legs, including any biomechanical or musculoskeletal deformities. The presence of equinus should be evaluated. The presence and degree of nodules within the tendon should be noted. The tendon should be palpated to determine the points of maximal tenderness. Crepitation on range of motion should be noted as well.
      Imaging modalities include plain radiography, ultrasonography, and MRI. Plain films rule out the presence of a Haglund deformity, spurring at the calcaneal insertion, or calcifications within the substance of the tendon. Ultrasonography can be used in the office setting to evaluate the tendon by evaluating the hypoechoic areas that correlate to nodular, multifocal, or diffuse injury. The hyperechoic areas may represent an accumulation of calcium deposits. MRI is still the best way to image the tendon. It can better differentiate between partial tears and focal degenerative areas of the tendon. MRI shows abnormalities in the tendon as a thickened paratenon, peritendinous fluid, edema in Kager triangle, fusiform thickening of the tendon, focal or diffuse intratendinous intermediate to high signal, or interrupted appearances of the tendon tissue.
      • Karjalainen P.T.
      • Soila K.
      • Aronen H.J.
      • et al.
      MR imaging of overuse injuries of the Achilles tendon.
      • Schweitzer M.E.
      • Karasick D.
      MR imaging of disorders of the Achilles tendon.

       Treatment

      Conservative treatments are more likely to fail in patients with tendinosis than in those with tendonitis. When conservative treatments have failed, more intensive treatments may be warranted. The author uses a protocol that may include a series of options presented to the patient in the form of aggressive conservative treatments to operative treatments. These options include a treatment ladder from extracorporeal shock wave therapy (ESWT), to platelet-rich plasma (PRP) injections, to percutaneous Topaz radiofrequency (RF) coblation, to microtenotomy of the tendon, to open surgical repair.
      When injury to the tendon is in a chronic state, there is a lack of blood flow, inflammation, and healing factors. The body has effectively stopped trying to heal the affected area. Theoretically, returning the tendon to an acute state of injury restarts the healing process and allows for healing and recovery. ESWT, PRP, and Topaz RF coblation are based on this theory.
      ESWT has been proved to be an effective method for the treatment of Achilles tendonitis over the last several years. Vulpiani and colleagues
      • Vulpiani M.C.
      • Trischitta D.
      • Trovato P.
      • et al.
      Extracorporeal shockwave therapy (ESWT) in Achilles tendinopathy. A long-term follow-up observational study.
      performed a study with 127 tendons with tendinosis. They used 4 sessions of ESWT treatment at 1500 to 2500 impulses at 0.08 to 0.4 mJ/mm2. They found satisfactory results in 42.2% of the patients after 2 months, 73.2% after 6 to 12 months, and 76% after 13 to 24 months. Furia
      • Furia J.P.
      High-energy extracorporeal shock wave therapy as a treatment for chronic noninsertional Achilles tendinopathy.
      studied 34 patients with tendinosis treated with ESWT against a control group of 34 patients treated conservatively. Patients were treated with a single dose of 3000 pulses at 0.21 mJ/mm2. He found that the percentage of patients with excellent (1) or good (2) Roles and Maudsley scores, that is, successful results, 12 months after treatment was statistically significant in the ESWT group compared with the control group.
      Rasmussen and colleagues
      • Rasmussen S.
      • Christensen M.
      • Mathiesen I.
      • et al.
      Shockwave therapy for chronic Achilles tendinopathy: a double-blind, randomized clinical trial of efficacy.
      compared ESWT to placebo in 48 patients. They found improvement in both groups during the follow-up period. However, at 8 and 12 weeks, there was an increased improvement in patients treated with ESWT compared with those receiving placebo. Fridman and colleagues
      • Fridman R.
      • Cain J.D.
      • Weil Jr., L.
      • et al.
      Extracorporeal shockwave therapy for the treatment of Achilles tendinopathies: a prospective study.
      performed ESWT at 21 kV, 2 Hz with 2000 pulses on 23 Achilles tendons followed up for 20 months. They found that 91% of the patients were satisfied or very satisfied, 87% related improvement, 13% related no improvement, and 0% related increased pain. They concluded ESWT to be safe, noninvasive, and effective for Achilles tendinosis. Lohrer and colleagues
      • Lohrer H.
      • Scholl J.
      • Arentz S.
      evaluated 40 Achilles tendons with tendinosis using ESWT, following up the patients for 1 year. Treatments were performed with 2000 impulses at between 0.06 and 0.18 mJ/mm2, with 5 sessions at weekly intervals. They found significant improvement in pain at rest, tenderness, load-induced pain, pain threshold, and pain-free running time as soon as 1 week after the end of the treatment. At the 1-year follow-up, results were even more improved. They concluded that ESWT seems to be an effective treatment modality for degenerative tendon lesions induced by running and jumping.
      The author uses the Swiss DolorClast (Electro Medical Systems, Dallas, TX, USA) to perform ESWT in the office setting (Fig. 3). It supplies a low-dose shock wave, which allows it to be a portable device. The machine uses compressed air impulses to accelerate the projectile in the headpiece. The impact of the projectile on the applicator generates the shock wave that is delivered to the tissue through the contact gel. The advantage of shock waves generated with the Swiss DolorClast is that they can produce an extensive analgesic effect to the area because the radiating shock waves extend to the entire area of pain. In most cases, no anesthetic is needed. The patient is positioned prone on the examination table. The machine should be set to deliver between 2000 and 3000 impulses at 5 to 10 impulses a second at 2 bar (0.06 mJ/mm2) initially. It can be increased to 4 bar (0.18 mJ/mm2) during the treatment if tolerable to the patient. Ultrasound gel is applied over the treatment area and the handpiece is placed over the tendon at the point of maximal pain. The machine is started using a foot pedal, while the handpiece is gently moved over the tendon. The patient wears a pneumatic walking boot for about 1 to 2 weeks. Most patients require up to 3 treatments 10 days to 2 weeks apart. Once all the treatments have been performed, the patient wears athletics shoes with orthotics and gradually returns to activity by physical therapy. During the initial recovery after each treatment, the patient is restricted from using antiinflammatory medications or modalities.
      Figure thumbnail gr3
      Fig. 3Swiss DolorClast (Electro Medical Systems, Dallas, TX).
      In recent years there has been an increased interest and use of PRP for chronic injuries of the foot and ankle. Platelets play an essential role in the healing cascade. When activated, they produce cytokines and granules that then produce growth factors that aid in the healing process. In the absence of inflammation in the chronic state, there is a paucity of platelets. The act of injecting a platelet-rich solution into the injured tissue increases the relative concentration of platelets in the tissue, thereby increasing the healing potential. There are an increasing number of studies testing the efficacy of PRP in cases of chronic Achilles tendinosis. PRP is thought to reverse the effects of tendinopathy by stimulating revascularization and improving healing at the microscopic level.
      • Alfredson H.
      • Lorentzon R.
      Chronic Achilles tendinosis: recommendations for treatment and prevention.
      Lyras and colleagues
      • Lyras D.N.
      • Kazakos K.
      • Verettas D.
      • et al.
      The influence of platelet-rich plasma on angiogenesis during the early phase of tendon healing.
      studied the effect of PRP on angiogenesis during tendon healing. The study was performed on the Achilles tendon of rats against a control group injected with saline. They found a significant increase in angiogenesis in the PRP group compared with the control group during the first 2 weeks of the healing process (ie, the inflammatory and proliferative phases), and the number of the newly formed vessels in the PRP group was significantly reduced at 4 weeks compared with the controls, suggesting that the healing process was shortened. They observed that the orientation of collagen fibers in the PRP group was better organized. The investigators concluded that PRP seems to enhance neovascularization, which may accelerate the healing process and promote scar tissue of better histologic quality.
      Gaweda and colleagues
      • Gaweda K.
      • Tarczynska M.
      • Krzyzanowski W.
      Treatment of Achilles tendinopathy with platelet-rich plasma.
      performed a prospective study on 15 patients with Achilles tendonitis. Patients were followed up for 18 months. They found improvement in pain scores and on ultrasound imaging. The American Orthopaedic Foot and Ankle Score improved from a median of 55 points to 96 points, and the achilles tendon score improved from 24 points to 96 points. They concluded PRP to be a viable treatment alternative for Achilles tendonitis.
      Recently, de Vos and colleagues
      • de Vos R.J.
      • Weir A.
      • van Schie H.T.
      • et al.
      Platelet-rich plasma injection for chronic Achilles tendinopathy: a randomized controlled trial.
      performed a stratified, block-randomized, double-blind, and placebo-controlled study. They included patients between the ages of 18 and 70 years with a diagnosis made clinically with findings of a painful and thickened tendon in relation to activity and on palpation, with symptoms lasting longer than 2 months. The PRP and control groups included 27 patients. They used 54 mL of whole blood to derive the PRP that was mixed with sodium bicarbonate to match the pH of tendon tissue. An undisclosed amount of PRP was injected into 5 sites along the injured tendon under ultrasonographic guidance. Patients were allowed to walk only short distances indoors in the first 48 hours. On days 3 to 7, patients were allowed to walk up to 30 minutes. After 1 week, an exercise routine was started, with 1 week of stretching and 12 weeks of daily eccentric exercise program with heel drops off a step. No weight-bearing sports activities were allowed for 4 weeks followed by a gradual return to activity. The results showed an improvement in 24 weeks by 21.7 points in the PRP group and 20.5 points in the placebo group. They concluded that there was no significant difference between the groups. At present, there are several prospective studies underway, investigating the true efficacy of PRP for Achilles tendinosis. The author’s clinical experience with more than 100 injections seems promising. A decrease in pain, size, and number of nodules and an earlier return to activity after PRP use has been observed.

       Technique

      A local anesthetic block is placed well above the site of injection around the level of the myotendinous junction. From the cubital vein, 60 mL of whole blood is collected. PRP is then prepared using the Magellan Autologous Platelet Separator System (Arteriocyte Medical Systems Inc, Cleveland, OH, USA). This device allows the operator to choose the amount of PRP desired by the clinician. A volume between 6 and 10 mL was chosen, yielding a concentration of PRP between 5 and 7 more than the baseline, respectively. The PRP is activated by calcium citrate and injected under ultrasonographic guidance within the substance of the tendon, beginning at the site of the pathologic condition (pain and any bulbous mass). The medial or lateral aspect of the tendon is approached with the patient in a prone position. Several pulsed (peppered) doses of about 0.25 mL at a time are injected using a 25-gauge needle, performing fenestrations of the tendon. The patient is restricted from using antiinflammatory medications or modalities for about 1 month after the procedure. Rescue medications such as acetaminophen or narcotics can be used as needed. The patient is placed in a walking boot on crutches (non–weight-bearing) for up to 1 week, then allowed to bear weight in the boot for the next 1 to 3 weeks. The patients are then allowed to wear athletic shoes, with a slow increase in weight-bearing activity over a 4-week period. A significant reduction in pain, a decrease in the size of fibrous nodules within the tendon, and a sooner return to regular and sporting activity after injection of PRP has been observed. Most patients have been able to return to increased exercise and activity within 2 months of the injection. Those patients who had only some improvement in their symptoms have benefited by a second injection about 6 weeks after the first.
      Another method to increase angiogenesis and stimulate healing in the avascular, fibrotic, and degenerative Achilles tendon is to use bipolar RF coblation or RF-based microtenotomy. Coblation is a controlled, non–heat-driven process using RF energy to excite the electrolytes in a conductive medium, such as saline solution, creating a precisely focused plasma. The plasma’s energized particles have sufficient energy to break the molecular bonds within tissue, causing the tissue to dissolve at relatively low temperatures (typically 40°C–70°C). The result is volumetric removal of target tissue with minimal damage to surrounding tissue. Because RF current does not pass directly through the tissue during the coblation process, tissue heating is minimal. Most of the heat is consumed in the plasma layer, that is, by the ionization process. These ions then bombard the tissues in their path, causing molecular bonds to simply break apart and the tissue to dissolve. RF-based microtenomy was researched early on in the treatment of congestive heart failure to promote angiogenesis.
      • Dietz U.
      • Horstick G.
      • Manke T.
      • et al.
      Myocardial angiogenesis resulting in functional communications with the left cavity induced by intramyocardial high-frequency ablation: histomorphology of immediate and long-term effects in pigs.
      • Fisher P.E.
      • Khomoto T.
      • DeRosa C.M.
      • et al.
      Histologic analysis of transmyocardial channels: comparison of CO2 and holmium:YAG lasers.
      • Kwon H.M.
      • Hong B.K.
      • Jang G.J.
      • et al.
      Percutaneous transmyocardial revascularization induces angiogenesis: a histologic and 3-dimensional micro computed tomography study.
      The research showed an increase in histologic and clinical outcomes as compared with other procedures. Early research on chronic tendinosis was performed by Tasto and colleagues.
      • Tasto J.P.
      • Cummings J.
      • Medlock V.
      • et al.
      The tendon treatment center: new horizons in the treatment of tendinosis.
      Results showed histologic evidence of an early inflammatory response and new blood vessel formation. Further research on human tendons showed improved function and less pain through 1 year by using what they deemed a simple and less-invasive technique.
      • Tasto J.P.
      The role of radiofrequency-based devices in shaping the future of orthopedic surgery.
      • Tasto J.P.
      • Cummings J.
      • Medlock V.
      • et al.
      Microtenotomy using a radiofrequency probe to treat lateral epicondylitis.
      Yeap and colleagues
      • Yeap E.J.
      • Chong K.W.
      • Yeo W.
      • et al.
      Radiofrequency coblation for chronic foot and ankle tendinosis.
      prospectively evaluated 15 procedures on chronic tendinosis of the Achilles, posterior tibial, and peroneal tendons using RF-based microtenotomy. They found a marked improvement in pain scores and earlier recovery than was found with other procedures. They concluded that RF-based microtenomy for chronic tendinosis shortens the natural history of disease in the tendon and hastens recovery and that the procedure may be especially useful for young competitive athletes who need a shorter rehabilitation time and quicker recovery.
      • Yeap E.J.
      • Chong K.W.
      • Yeo W.
      • et al.
      Radiofrequency coblation for chronic foot and ankle tendinosis.
      Liu and colleagues
      • Liu Y.J.
      • Wang Z.G.
      • Li Z.L.
      • et al.
      evaluated 17 cases of Achilles tendinosis treated with RF-based microtenomy. They performed the procedure using arthroscopy. They found a significant reduction in visual analog scale pain scores from 8.7 to 1.6 about 15 days after the procedure and a marked improvement within 7 to 14 days after the surgery. They also concluded the procedure to be a safe, effective, and minimally invasive to decrease pain and lead to early rehabilitation.
      The patient is placed on the operating table in a prone position. The area is anesthetized above the level of the treatment area, and the area is prepared for surgery. The procedure can be performed percutaneously. The author uses the Topaz MicroDebrider (ArthroCare, Sunnyvale, CA, USA) connected to a generator and timer. This technique uses a bipolar, controlled, plasma-mediated RF-based process (coblation). The probe is connected to a saline drip to control the temperature and is set to 1 to 2 drops every 3 seconds. A timer is used to control the amount of microtenotomy at 500 milliseconds. The control unit is set to level 4 (175 V). In a gridlike pattern, percutaneous holes are made through the skin using a Kirschner wire over the pathologic area, while the foot is dorsiflexed to reduce the skin wrinkles. The probe is then inserted through each hole, advancing the wand to the level of resistance against the tendon, and the RF-based microtenomy is performed at about 5-mm intervals at differing depths. The wound is dressed with sterile dressing, and compression is applied. The patient wears a pneumatic walking boot with limited weight bearing for a period of 3 weeks and then wears athletic shoes, and there is a slow increase in activity through physical therapy during the next 3 to 6 weeks. During the first 2 months, the patient should refrain from using antiinflammatory medications or modalities, because inflammation is what the procedure is trying to achieve. Promising results have been seen with several cases using the Topaz RF coblation in both percutaneous and open procedures, with improvement in pain and earlier recovery and return to activities.
      Surgical repair of the tendon has been the gold standard in the treatment of recalcitrant Achilles tendinosis when conservative treatments have failed. With the advent of ESWT, RF coblation, and PRP, these techniques should be tried before considering open repair. Open surgery is performed when one or all these therapies have failed. Surgical procedures involve the removal of abnormal tissue and lesions, fenestration of the tendon through multiple longitudinal lacerations, and possibly stripping the paratenon. The goal of open surgery is to remove degenerative nodules, excise fibrotic adhesions, restore vascularity, and stimulate viable cells to initiate an inflammatory response to reinitiate healing.
      • Benazzo F.
      • Maffulli N.
      An operative approach to Achilles tendinopathy.
      • Clancy W.G.
      Runners’ injuries. Part two. Evaluation and treatment of specific injuries.
      • Clancy W.G.
      • Heiden E.A.
      Achilles tendinitis treatment in the athletes. Contemporary approaches to the Achilles tendon.
      • Clancy Jr., W.G.
      • Neidhart D.
      • Brand R.L.
      Achilles tendonitis in runners: a report of five cases.
      • Rolf C.
      • Movin T.
      Etiology, histopathology, and outcome of surgery in achillodynia.
      The aforementioned techniques can also be used in conjunction with an open surgical technique. The Topaz RF coblation probe can be used in lieu of performing lacerations or perforations within the tendon once opened (Fig. 4). Once any abnormal tissue has been removed, RF-based microtenomy can be performed to the tendon in several locations in a grid pattern at several different depths. If the tendon was sectioned sagittally to remove abnormal tissue, RF-based microtenomy can be performed within the substance of the tendon before repairing it. If the surgeon decides that there is no need to remove abnormal tissue, adhesions, or nodules, RF-based microtenomy can be performed percutaneously. PRP can be used during an open surgery as an adjunct to the repair. A layer of concentrated platelets may be sprayed over the tendon before closure of the paratenon. PRP can also be prepared as a gel by adding thrombin to it. This gel can be molded into any shape to be wrapped around and sutured to the tendon. With either method, the foot is placed in a pneumatic walker or cast and the patient uses crutches for a period of 3 to 5 weeks. Physical therapy is ideal in these cases to begin a slow progression to increased activity and strength.
      Figure thumbnail gr4
      Fig. 4Open treatment of Achilles tendinosis using Topaz coblation leaving tendon intact (A). Open treatment of Achilles tendinosis using Topaz collation after removal of scarred tendon (B).

       Rupture

       Injury

      The Achilles tendon is one of the most commonly ruptured tendons in the human body.
      • Jozsa L.
      • Kvist M.
      • Balint B.J.
      • et al.
      The role of recreational sport activity in Achilles tendon rupture. A clinical, pathoanatomical, and sociological study of 292 cases.
      Most ruptures are observed in male patients between the ages of 30 and 50 years. About 75% of ruptures have been shown to occur during sports-related activities.
      • Cetti R.
      • Christensen S.E.
      • Ejsted R.
      • et al.
      Operative versus nonoperative treatment of Achilles tendon rupture. A prospective randomized study and review of the literature.
      Most researchers agree that the precursor is some sort of overuse and that repetitive loading plays a role in the pathophysiology leading to a rupture; however, no direct relationship between physical activity and histopathology has been found.
      • Clain M.R.
      • Baxter D.E.
      Achilles tendinitis.
      Most agree that patients who have a chronic tendinosis have a higher incidence and chance of rupture.
      • Jozsa L.
      • Kvist M.
      • Balint B.J.
      • et al.
      The role of recreational sport activity in Achilles tendon rupture. A clinical, pathoanatomical, and sociological study of 292 cases.
      • Aroen A.
      • Helgo D.
      • Granlund O.G.
      • et al.
      Contralateral tendon rupture risk is increased in individuals with a previous Achilles tendon rupture.
      • Kannus P.
      • Jozsa L.
      Histopathological changes preceding spontaneous rupture of a tendon. A controlled study of 891 patients.
      The rupture usually occurs at the watershed point in the tendon, where it has the least vascularity, approximately 2 to 6 cm proximal to its insertion. A rupture usually occurs when there is an extreme or sudden force on a resting or weakened tendon.

       Diagnosis

      The diagnosis of an Achilles tendon rupture is usually made based on the patient’s history and clinical examination. Patients present describing feeling a sudden pop or snap in the back of the leg and ankle while they were performing an intense physical activity or sudden propulsion. They usually describe the sensation as though they were struck in the back of the ankle and then feeling sudden pain. Most patients relate the pain as subsiding soon after the injury and being able to walk with only a slight limp. For this reason, many ruptures are diagnosed weeks later because the patients think they only sprained their ankle.
      Physical examination of the tendon reveals ecchymosis and edema surrounding the posterior ankle and the tendon. A palpable dell or defect can be appreciated at the rupture site. The Thompson-Doherty test can be applied by having the patient in a prone position and squeezing the calf from side to side. If the foot does not plantar flex, the test result is negative. Patients are unable to perform single-heel raises on the affected side. MRI can confirm the diagnosis and help determine the amount of retraction of the proximal portion of the tendon.

       Treatment

      Open surgical repair is the gold standard for the ruptured Achilles tendon. There have been many procedures described to reapproximate the tendon ends using different suturing techniques and materials. The goal is to have a direct end-to-end anastomosis, usually possible in acute cases. Once the tendon has been exposed, the hematoma removed, and the tendon ends prepared, most surgeons perform some form of the Krackow suture technique, modified Krackow technique, the Bunnell technique, or the modified Kessler stitch. The Krackow stitch has been shown to be stronger than the Bunnell or the modified Kessler stitch.
      • Krackow K.A.
      • Thomas S.C.
      • Jones L.C.
      A new stitch for ligament-tendon fixation. Brief note.
      The author uses a new type of suture material and technique called a FiberLoop (Arthrex, Inc, Naples, FL, USA). FiberWire is a suture made of a nonabsorbable polyethylene core with a braided polyester jacket. FiberLoop is no 2 or 2-0 FiberWire in a continuous loop on a straight nitinol needle. The looped structure of the suture construct allows for a simpler and faster technique for running a whipstitch through the tendon. Botero and Svoboda
      • Botero H.
      • Svoboda S.
      Comparison of the Krackow locking loop stitch to a novel continuous loop suture technique for fixation of free tendon ends.
      performed a small study for Arthrex, comparing the Krackow stitch to no 2 FiberLoop, testing their failure load and elongation at failure on porcine tendons. They found that the FiberLoop whipstitch technique provided the best fixation with regard to peak failure load and allowed more elongation than the Krackow FiberWire technique; however, its performance was comparable to the Krackow technique using Ethibond (Ethicon, Somerville, NJ, USA) in resisting elongation with regard to elongation at failure. Cook and colleagues
      • Cook K.D.
      • Clark G.
      • Lui E.
      • et al.
      Strength of braided polyblend polyethylene sutures versus braided polyester sutures in Achilles tendon repair: a cadaveric study.
      studied 12 cadaveric Achilles tendons comparing the strength of 2-0 FiberLoop to No. 2 Ethibond suture. They found that the smaller-caliber 2-0 FiberLoop maintained a greater load-to-failure strength than No. 2 Ethibond. They concluded that a thicker suture material, as used traditionally in Achilles tendon repair, may be substituted by the thinner and stronger FiberLoop material.

       Technique

      Once the tendon ends are prepared, the “loop” of the No. 2 or 2-0 (depending on the size of the tendon and the amount of retraction) FiberLoop suture is placed around the proximal aspect of the ruptured tendon about 5 cm from the stump. The suture is oriented so that the needle is posterior and the central aspect of the loop is hugging the tendon on its underside or anterior aspect. An Edna clamp is placed on the end of the tendon for counterpressure. One hand is used to grasp the loop posterior to the tendon, lifting it posterior and proximal, while the other hand drives the nitinol needle into the central posterior aspect of the tendon about 5 mm distal to the loop, exiting the anterior aspect of the tendon. The needle is pulled tight, closing the first loop around the tendon. The next pass is performed by looping the suture over the tendon once again and passing the needle from posterior to anterior through the tendon just distal to the loop and about 5 mm from the previous loop. This looping continues until the suture reaches the distal aspect of the end of the tendon. There should be 5 or more loops around the tendon. The suture is cut at the level of the needle, and each free end of the suture is passed through the tendon from medial to lateral and from lateral to medial, respectively, with the free needle. There should now be a free suture on each side of the proximal stump of the tendon. The same technique is not performed on the distal stump of the tendon with another FiberLoop. Care should be taken to place the first loop as distal as possible to have at least 5 passes through the tendon. With the ankle in maximal plantar flexion, the medial or lateral sutures are sutured together, reapproximating the ends of the tendon with 1 knot to hold it in place. The next suture is then tied several times holding the ends of the tendon tight. Attention is now redirected to the previous knot, and it is tightened again with several more knots. The repair can be augmented at the anastomosis if needed with a 2-0 FiberWire suture. The author has found this suture construct and technique to use less suture material and to be less constrictive on the tendon, more efficient, and simpler to perform than the more traditional types of whipstitch and suture materials.
      Now that the tendon ends are repaired, it may be beneficial to augment the repair with some extracellular matrix scaffolding (Fig. 5). There has been a great interest in biologic reinforcement and augmentation of soft tissue and tendon repairs with materials that can be wrapped around the tendon to increase strength, decrease healing time, and decrease scar tissue formation within the tendon. Research and advancements have provided numerous materials in the form of allografts and xenografts, which can be easily prepared and applied to the tendon. These acellular regenerative tissue scaffolds are usually allogenic permanent dermal equivalents derived from human cadaveric tissue that is processed in a way that minimizes the destruction of the original human dermis.
      • Callcut R.A.
      • Schurr M.J.
      • Sloan M.
      • et al.
      Clinical experience with alloderm: a one-staged composite dermal/epidermal replacement utilizing processed cadaver dermis and thin autografts.
      Vascular pathways in the dermis and extracellular matrix, which contains all collagen types, elastin, proteoglycans, laminins, and tenacin, are preserved in the allograft.
      • Rubin L.
      • Schweitzer S.
      The use of acellular biologic tissue patches in foot and ankle surgery.
      These scaffolds are prepared to allow for rapid revascularization, cellular repopulation, their ability to maintain tensile strength, and their lack of immunologic host response. These materials do not interfere with healing or become encapsulated like most foreign bodies.
      Figure thumbnail gr5
      Fig. 5Achilles tendon rupture repair wrapped with different types of extracellular matrix scaffold (A, B, C).
      Several studies have shown the effectiveness (increased strength) and histologic incorporation of these acellular scaffolds in both human and animal tendons.
      • Valentin J.E.
      • Badylak J.S.
      • McCabe G.P.
      • et al.
      Extracellular matrix bioscaffolds for orthopaedic applications. A comparative histologic study.
      • Snyder S.J.
      • Arnoczky S.P.
      • Bond J.L.
      • et al.
      Histologic evaluation of a biopsy specimen obtained 3 months after rotator cuff augmentation with GraftJacket matrix.
      • Liden B.A.
      • Simmons M.
      Histologic evaluation of a 6-month GraftJacket matrix biopsy used for Achilles tendon augmentation.
      • Lee D.K.
      A preliminary study on the effects of acellular tissue graft augmentation in acute Achilles tendon ruptures.
      • Lee D.K.
      Achilles tendon repair with acellular tissue graft augmentation in neglected ruptures.
      Barber and colleagues
      • Barber F.A.
      • McGarry J.E.
      • Herbert M.A.
      • et al.
      A biomechanical study of Achilles tendon repair augmentation using GraftJacket matrix.
      examined the strength and stiffness of 8 pairs of repaired cadaveric Achilles tendon ruptures, comparing suture repair with and without graft augmentation using GraftJacket (Wright Medical Technology, Arlington, TN, USA). They noted a significant increase in the strength (failure load of 217 to 455 N, control vs augmented tendon, respectively) and stiffness (4.3 to 12.99 N/mm, control vs augmented tendon, respectively) of the repaired tendons using the GraftJacket. Liden and Simmons
      • Liden B.A.
      • Simmons M.
      Histologic evaluation of a 6-month GraftJacket matrix biopsy used for Achilles tendon augmentation.
      histologically evaluated biopsies taken from Achilles tendon repairs with GraftJacket 6 months after surgery. They concluded that the acellular dermal matrix is biocompatible, supports revascularization and repopulation with noninflammatory host cells, and becomes incorporated by the surrounding tendon tissue.
      There are many different materials on the market. Chen and colleagues
      • Chen J.
      • Xu J.
      • Wang A.
      • et al.
      Scaffolds for tendon and ligament repair: review of the efficacy of commercial products.
      reviewed 47 articles relating to different types of scaffolds and their effects on ligament and tendon repair augmentation. They found many products being used and both positive and negative reports on each. These products included the Restore Patch (DePuy Orthopedics, Warsaw, IN, USA), GraftJacket, Zimmer Collagen Repair Patch Graft (Zimmer, Warsaw, IN, USA), and TissueMend (Stryker Orthopedics, Mahwah, NJ, USA). The author usually uses GraftJacket for the reinforcement of an acute Achilles tendon rupture repair. Other studies compared these different products with one another to determine the strength and chemical properties and concluded that the chemical and mechanical differences between the materials may be because of the source (dermis or small intestine), species (human, porcine, or bovine), age of donor (fetal or adult), and processing of the extracellular matrix.
      • Derwin K.A.
      • Badylak S.F.
      • Steinmann S.P.
      • et al.
      Extracellular matrix scaffold devices for rotator cuff repair.
      • Derwin K.A.
      • Baker A.R.
      • Spragg R.K.
      • et al.
      Commercial extracellular matrix scaffolds for rotator cuff tendon repair. Biomechanical, biochemical, and cellular properties.
      PRP in the form of a fibrin gel (when combined with thrombin) can also be used as a tendon scaffold. It can be used as a bridge and augmentation within the rupture defect or can be wrapped around the tendon repair. In most cases, PRP is combined with bone marrow aspirate for further enhancement of the PRP matrix. Sarrafian and colleagues
      • Sarrafian T.L.
      • Wang H.
      • Hackett E.S.
      • et al.
      Comparison of Achilles tendon repair techniques in a sheep model using a cross-linked acellular porcine dermal patch and platelet-rich plasma fibrin matrix for augmentation.
      performed a study to compare a cross-linked acellular porcine dermal patch (APD) with a PRP fibrin matrix (PRPFM) for repair of acute Achilles tendon rupture in a sheep model. The 2 surgically transected tendon ends were reapproximated in groups 1 and 2, whereas a gap was left between the tendon ends in group 3. APD was used to reinforce the repair in group 2, and autologous PRPFM was used to fill the gap, which was also reinforced with APD, in group 3. Tensile strength testing showed a statistically significant difference in elongation between the operated limb and the unoperated contralateral limb in groups 1 and 3 but not in group 2. In group 1, all surgical separation sites were identifiable, and healing occurred via increasing tendon thickness. In group 2, healing occurred with new tendon fibers across the separation, without increasing tendon thickness in 2 of 6 animals. Group 3 showed complete bridging of the gap, with no change in tendon thickness in 2 of 6 animals. In groups 2 and 3, peripheral integration of the APD to tendon fibers was observed. They concluded that the use of APD, alone or with PRPFM, to augment Achilles tendon repair in a sheep model allowed for a viable and strong repair.
      After the tendon ends are repaired and the graft material has been prepared (soaked and trimmed to its proper length), it is wrapped circumferentially around the tendon, with the rupture site central on the graft. The seam of the graft should be centered over the tendon. The dermal side of the graft should be lying over the tendon. The graft is anchored at its proximal lateral corner to the tendon using a 4-0 nonabsorbable suture. The graft is then pulled taut at the distal-lateral corner while the assistant is holding the medial portion of the graft tight, and this corner is anchored to the tendon. The medial portion of the graft is now cut to its proper width to a level where it meets with the opposing lateral aspect of the graft while being taut. The remaining corners are now sutured in the same manner. The central aspect of the tendon is then sutured to itself with every other suture passing through the tendon. Interlocking sutures are not used, so that if the knot slips it does not unravel the repair. If there is available paratenon, it can be reapproximated over the graft. A significant decrease in healing time and increased strength in less time has been observed when using Achilles tendon augmentation. Patients generally have their foot placed in a cast for 3 weeks and are then allowed to begin progressive weight bearing and intensive physical therapy, sooner than those without grafting. There has also been a significant enhancement in the definition of the tendon complex with less edema and thickness to the tendon compared with those repaired without augmentation.

      Summary

      The number of new technologies and techniques in the treatment of foot and ankle injuries is widespread. In many cases, a surgeon may be introduced to a new technique that is exciting and sound in theory but does not live up to its potential in practice. New technologies that are replacing old ones must have certain criteria. These criteria include less complications, decreased comorbidity, decreased healing time, decreased recovery time, increased patient satisfaction, decreased pain, increased function, and cost effectiveness. It is the responsibility of the clinicians and surgeons to differentiate between those technologies that are fruitful and increase patient care and those that are redundant or harmful. Clinical testing of both in vivo and in vitro studies is critical to best evaluate the efficacy of new technologies. The literature and clinical evidence for the use of the technology and techniques in this review are promising. Yet, more well-designed prospective studies examining these products and techniques are essential to establish them as the gold standard.

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