The Pesky Peroneal Tendons & Tales of Subluxation

Jason R. Miller, DPM, FACFAS Residency Director, Phoenixville Hospital PMSR/RRA Director, PA Intensive Lower Extremity Fellowship Program Adjunct Associate Professor, Dept. of Surgery, TUSPM Chief, Foot & Ankle Surgery, Pennsylvania Orthopaedic Center/Premier Orthopedics Presentation

• Overall, peroneal tendon disorders are reportedly rare, with peroneal brevis involvement being more common than peroneus longus involvement, and with both longus and brevis involvement being the least common • Associated with lateral ankle sprain or insult, but occasionally no traumatic event is noted in patient’s history • Frequently overlooked and misdiagnosed due to assumption the injury is to the lateral ankle ligaments

Molloy, R. et al (2003). Failed Treatment of Peroneal Tendon Injuries. Foot and Ankle Clinics of North America, 8, pp. 115-129. Becker, H.P. et al (1996). Functional Disorders of the Foot After Tenodesis: Is the Method Still Currently Acceptable? Sportverletz Sportschanden, 10:4, pp. 94-99. Presentation

• Tears are generally degenerative in nature, look for history of repetitive lateral ankle sprains/lateral ankle instability • More commonly associated with a cavus foot type, hindfoot varus, and peroneal subluxation • Swelling along the peroneals is the most consistent clinical finding on exam (as much as 90%)

Molloy, R. et al (2003). Failed Treatment of Peroneal Tendon Injuries. Foot and Ankle Clinics of North America, 8, pp. 115-129. Slater, H.K (2007). Acute Peroneal Tendon Tears. Foot and Ankle Clinics of North America, 12, pp. 759-674. Squires, N. et al (2007). Surgical Treatment of Peroneal Tendon Tears. Foot and Ankle Clinics of North America, 12, pp. 675-695. Diagnosis of Injury (Acute Injury)

• Diagnosis made by clinical presentation • Dorsiflexion and eversion in ski boot • Lateral collateral injury via: • 1) plantarflexion • 2) inversion • Tenderness to palpation: • Posterior aspect of the fibular along the peroneal retinaculum • ATFL would present with pain anterior to the fibula (+AD) • Patient rarely presents with subluxed peroneals • Patient apprehensive to DORSIFLEX and EVERT foot (instability) Diagnosis of Injury (Chronic Injury) • Patient presents with: • Feeling of instability in lateral ankle • Feeling clicking posterior to the lateral malleolus • With finger pressed posterior to the lateral malleolus rotate ankle in circular fashion and feel for tendon subluxation • Always compare tightness of retinaculum to uninvolved side. • Longitudinal fissure of peroneal tendon may be noted: • Clicking with dorsiflexion and plantarflexion of foot along peroneals may be indicative of fissure often mimicking subluxation. Imaging

• Xray: rule out fx, avulsion, Os Peroneum. Look for anatomy causing mechanical insult to tendons • MRI: high chance of false positive and false negative, as well as over/under estimating extent of damage • MSK U/S: probably best when looking for subluxation or subtle tears. • While prudent to obtain, open surgical visualization is the gold standard

Squires, N. et al (2007). Surgical Treatment of Peroneal Tendon Tears. Foot and Ankle Clinics of North America, 12, pp. 675-695. Imaging

Arrow showing “valgus erosion”, possibly contributing to peroneal impingement/dege neration

Slater, H.K (2007). Acute Peroneal Tendon Tears. Foot and Ankle Clinics of North America, 12, pp. 759-674. Brief Anatomical Review: • Peroneal Brevis Muscle • O: Distal ½ of the Lateral Surface of Fibular Shaft • I: Styloid Process of 5 th Metatarsal Laterally • Peroneus Longus Muscle • O: Fibular Head and Proximal ½ of Lateral Fibular Shaft • I: 1) Lateral and Plantar Aspects of Medial Cuneiform 2) 1 st Metatarsal Tuberosity • Both in Lateral Compartment of Foot • Arterial Supply: Peroneal (Fibular) Artery • Nerve Innervation: Superficial Peroneal (Fibular) Nerve Anatomical Review of Peroneals

• Peroneus Longus is POSTERIOR to the Peroneus Brevis Posterior to the Lateral Malleolus • Peroneal Tendons Retained by 3 Tunnels: • 1) Retromalleolar Tunnel (PB and PL) • Formed by Superior Peroneal Retinaculum (SPR) • At the level of distal fibular • 2) Inferior Tunnel (PB and PL Split) • Formed by Inferior Peroneal Retinaculum • At the level of Process Trochlearis (Peroneal Tubercle) • 3) Plantar Tunnel (PL) • Cuboid and Base of 5 th Metatarsal Anatomical Review of Peroneals • Peroneal Brevis Muscle • O: Distal ½ of the Lateral Surface of Fibular Shaft • I: Styloid Process of 5 th Metatarsal Laterally • Peroneus Longus Muscle • O: Fibular Head and Proximal ½ of Lateral Fibular Shaft • I: 1) Lateral and Plantar Aspects of Medial Cuneiform 2) 1 st Metatarsal Tuberosity • Both in Lateral Compartment of Foot • Arterial Supply: Peroneal (Fibular) Artery • Nerve Innervation: Superficial Peroneal (Fibular) Nerve Anatomical Review of Peroneals

• Peroneal Synovial Sheath • Extends from level just superior to lateral malleolus  to the level of the cuboid • Passes deep to both superior and inferior peroneal retinaculum • Peroneal Tubercle (Lateral Calcaneal Body) • Inferior peroneal retinaculum has fibers that attach to tubercle • Synovial sheath splits at this level • Peroneus Brevis travels SUPERIOR • Peroneus Longus travels INFERIOR Anatomical Review of the Peroneals

• Posterior Fibular Retromalleolar Groove • Posterior aspect of the fibular head • Both Peroneal tendons travel distal within groove • Superior Peroneal Retinaculum • O: Lateral Border of Retromalleolar groove and Tip of the Lateral malleolus • I: In the aponeurosis of Achilles Tendon Retromalleolar Groove Tunnel

• Fibro-osseous Tunnel which maintain the peroneals • Medial Border: PTFL and CFL • Anterior Wall: Posterior Lateral Malleolus • Posterior Wall: Superior Peroneal Retinaculum • Lateral Border: Superior Peroneal Retinaculum Peroneal Tendons (Lateral Ankle View) Actions of the Peroneal Muscles

• Peroneus Longus • Eversion and Plantarflexion of foot • Pronates Subtalar and Midtarsal Joint • Plantarflexes Ankle Joint • Stabalizes 1st Met during Propulsive phase of Gait • Peroneus Brevis • Eversion and Plantarflexion of foot • Prontation of Subtalar Joint • Flexes Ankle Joint • **Hintermann et el 1994 found to be strongest everter of foot My God my Lateral Ankle !!!! What are Subluxing Peroneals? • Described as a rupture of Superior Peroneal Retinaculum which is the sling that holds the peroneal tendons stable within the retromalleolar groove • Weakest Attachment of SPR at fibula *** • Without stabilization the peroneals may sublux out of the groove with activity • Monteggia et al first described the injury in 1803 with Ballet Dancers in Italy • Most common sporting injury = Skiing (Clanton et al – 71% of 265 cases) Are Subluxing Peroneals in your Future?

• Edwards et al in 1928 states some are more prone to superior peroneal retinaculum injury (cadaveric study 110 cadavers): • 1) Retromalleolar groove is concave in shape but he found that 7% convex and 11% are flat • Width of sulcus varies from 5-10 mm • 2) Fibrous ridge noted on posterolateral aspect of fibula that aids in peroneal stabilization, ABSENT in 30% • Deepens sulcus by 1-2 mm • Factored in during Eckert Classification Mechanism of Injury

• Most Common: Sudden dorsiflexion stress at ankle coupled with violent contraction of Peroneals • In skiers happens when: • 1) When tip of ski is lodged in snow • 2) Sudden deceleration of ankle in dorsiflexed position • 3) Which causes forceful contraction of Peroneals to stabilize • Been reported with forceful eversion to edge down mountain • Places extra force on CFL which narrows fibo-osseous tunnel • Pushes peroneals into retinaculum Lesson: Careful Skiing Eckert and Davis Classification (1976 JBJS) • Grade 1: SPR stripped off fibular (51%) • Grade 2: Fibrous rim avulsed off fibular with SPR (33%) • Grade 3: Boney Avulsion of PL fibula by SPR (16%) • Grade 4: Added by Oden 2003*** Rupture of SPR • Key: • 1 = PB • 2 = PL Imaging for Diagnosing Peroneal Sheath Injury • Plain Radiograph • Can see posterior fleck at the distal fibular indicative of avulsion. (Grade 3 Eckert and Davis) • Rare injury and plain radiograph usually non-diagnostic • CT Scan • Precise definition of retromalleolar sulcus and position of peroneal tendons • MRI (***Gold Standard***) • Shows soft tissue structures • Often shows pouch between periosteum and fibula that contain peroneal tendons Imaging of Peroneal Sheath Injury MRI CT MRI Findings Correlation w/MRI Findings Conservative Treatment

• When diagnosed patient should be placed in NWB molded cast • A piece of felt is placed posterior to the lateral malleolus for pressure • The pressure on the peroneals will hopefully help periosteum to re-adhere • McLennan, Stover, and Bryan et al reported 50% success with this method • 3 weeks NWB and 3 weeks WB in cast • Escalas et al reported 73% treated initially with conservative had re-occurrence and had surgical repair • High Lateral flange or heel lift also could be utilized by some authors Surgical Intervention for Subluxing Peroneals

• Clanton et al states there are 5 categories for surgical repair: • 1) Reattachment of retinaculum and reinforcement with local tissue • 2) Bone block procedures • 3) Reinforcement of Superior Peroneal Retinaculum with transfer tissue (Achilles tendon, palmaris, etc.) • 4) Re-routing procedures (e.g. under CFL) • 5) Groove deepening procedures *Adults vs. Kids? Soft Tissue Reconstructions

• Aimed to obliterate pouch between periosteum and fibula • Longitudinal incision made 1 cm superior to SPR to the distal fibula • Inspect peroneals for tears and dissect to posterior lateral fibula • Several drill holes made in fibula and retinaculum is reattached obliterating the free space. (Pouch) • Tendon sheath is repaired and NWB for 3 weeks • Clanton et al reported 3% re-occurrence • Kraske and Krammer et al used Periosteal Fibular Flap Re-routing under CFL (Platzgummer technique ) Superior Retinaculoplasty Bone Block Procedures

• Indicated in patient who has failed previous soft tissue procedures (adults?) • Duvries procedure is accepted procedure of choice • 1st bone cut 1 cm proximal from tip of fibula • 2nd bone cut made more proximal to 1 st (0.5 – 1cm) • Anterior aspect of wedge should be 2cm and posterior aspect 1.5 cm (ensures tight wedge) • Fixation via 2-hole plate • 4 weeks cast NWB , 4 weeks cast WB Duvries Boney Block Procedure Tissue Transfer Procedures

• Used to reinforce SPR due to incompetency • Jones procedure uses slip of Achilles Tendon to reinforce the SPR • Risk = Damage to sural nerve, loss ankle plantarflexion tone • 7 cm slip of Achilles re-routed from posterior to anterior • This done threw drill hole in fibula • Anderson et al used strip of fascia latae • Lexer et al harvested Palmaris Longus Re-routing Procedures

• Wolf et al rerouted ligaments under the CFL ligament • This technique required tenotomy and later repair of ligaments • Disadvantage = Weakened Peroneals (split) • Platzgummer et al described similar procedure but: • 1) Divided the CFL ligament as opposed to Peroneal tendons • 2) SPR repair coupled with his rerouting procedure • Poll et al describes taking bone plug with insertion of SPR and bone anchor into place • Used in Pediatric Patients in order to not disturb growth center with bone work (Stiffness) Groove Deepening Procedures

• Based off of Edwards Cadaveric study • Some advocate osteotome and burr raw surface • Thompson et al described technique: • Osteomized fibula of 3 sides leaving hinge (Post-medial) • Cancellous bone then rongeured out • Flap of bone placed back in place over raw surface • Technically difficult but Clanton reported NO reoccurrence in 17 cases • Kollias and Ferkel reported 10/11 athletes returned to sports following procedure • Best results with deepening of 3-8 mm Groove Back? How ‘d she get it back?

• Zoellner & Clancy (1979) Periosteal flap, excision of bone, swingback, depress 3-4cm in length, no depth discussion • Akiki (2007) Modified Zoellner, leave tissue, burr 3- 8mm deep • Ogawa (2007) Drill, tamp • Walther (2009) Modified Ogawa, drilled, then used osteotome prior to tamping • Miller (2010) unofficial modification of Ogawa, use of back end of a hollow handle bone curette. Z&C Groove Deepening Procedure

Free tissue carefully off distal fibula Drill bit position confirmation by C- Arm , sizing 4-5.5mm Peroneal Groove Deepening: Biomechanical Study of Pressure Reduction • Noted changes in pressure through peroneal groove post-deepening (cadaveric study 12 limbs) • Pressure pads positioned at: • 1) CFL • 2) Distal groove • 3) Middle groove • 4) Proximal groove • Mean pressure over CFL increased in all 5 ankle positions (not significant) • DECREASED pressure in middle and distal groove • Aids in reduction of pressure for subluxation risk • Friction reduction prevents future tendonitis Case Study: ‘The Too Big Tubercle’ How do we handle the Petulant Peroneal?

• What options do we have if the tendons are “too far gone”? • Do we use synthetics or biologics to graft? • Cadaveric grafts? • Attempt direct repair with PRP/Amnion grafts? • Let’s discuss the options……. Definition • Peroneal anastomosis AKA peroneal tenodesis • Involves surgical attachment of the peroneus brevis tendon to the peroneus longus tendon, or vice versa • Traditionally utilized as standard salvage procedure following acute or chronic peroneal tendon injury, but lacking analytical support

Stamatis, E.D. et al (2014). Salvage Options for Peroneral Tendon Ruptures. Foot and Ankle Clinics of North America, 19, pp. 87-95 Presentation

Molloy, R. et al (2003). Failed Treatment of Peroneal Tendon Injuries. Foot and Ankle Clinics of North America, 8, pp. 115-129. Imaging

Squires, N. et al (2007). Surgical Treatment of Peroneal Tendon Tears. Foot and Ankle Clinics of North America, 12, pp. 675-695. Cerrato, N. et al (2009). Peroneal Tendon Tears, Surgical Management and Its Complications. Foot and Ankle Clinics of North America, 14, pp. 299-312. Imaging

• Utilize T2 for better visualization • Use MRI to simply identify that a tendon pathology exists, rather than the extent of the pathology

Squires, N. et al (2007). Surgical Treatment of Peroneal Tendon Tears. Foot and Ankle Clinics of North America, 12, pp. 675-695. Pellegrini, M.J. et al (2014). Reversal of Peroneal Tenodesis With Allograft Reconstruction of the Peroneus Brevis and Longus: Case Report and Surgical Technique. Foot and Ankle Specialists, 7:4, pp. 327-331. Conservative Treatment

• Offloading/rest with the use of a cast or CAM boot for 4-6 weeks • Bracing to correct/accommodate deformity contributing to symptoms • PT • NSAIDS • Frequently unsuccessful (60-70%)*

Filiatrault, A.D. et al (2015). Peroneus Longus Tendon Rupture Repair: Case Presentations. The Podiatry Institute Chapter Update, 32, pp. 167- 173. Classification • The vast majority of the cases that go on to surgical intervention rely on intra-operative assessment • Visual assessment is graded using classification systems to help guide treatment

Filiatrault, A.D. et al (2015). Peroneus Longus Tendon Rupture Repair: Case Presentations. The Podiatry Institute Chapter Update, 32, pp. 167- 173. Krause & Brodsky

• Applies to peroneus brevis tears after surgical debridement of non- viable tissue • Grade 1- 50% or more of cross sectional area remains: direct longitudinal repair • Grade 2- less than 50% of the cross sectional area remains: resect damaged area and tenodesis to peroneal longus

Molloy, R. et al (2003). Failed Treatment of Peroneal Tendon Injuries. Foot and Ankle Clinics of North America, 8, pp. 115-129. Redfern & Myerson

Cerrato, N. et al (2009). Peroneal Tendon Tears, Surgical Management and Its Complications. Foot and Ankle Clinics of North America, 14, pp. 299-312. Sobel et al

• Based on length of defect • Not correlated with any treatment options

Cerrato, N. et al (2009). Peroneal Tendon Tears, Surgical Management and Its Complications. Foot and Ankle Clinics of North America, 14, pp. 299-312. Peroneal Anastomosis

• A well established “salvage” procedure • Relatively easy/simple procedure • For Krause & Brodsky Grade 2 or Redfern & Myerson type 2 • Extent of damage assessed intraoperative after opening superior and inferior peroneal retinaculum

Stamatis, E.D. et al (2014). Salvage Options for Peroneral Tendon Ruptures. Foot and Ankle Clinics of North America, 19, pp. 87-95. Peroneal Anastomosis

• Incision from posterior superior to the lateral malleolus along the peroneals to the 5 th met base • Layered anatomic dissection with special care taken to isolate and retract the sural nerve • Full exposure of peroneal retinaculum is needed. These are then incised and retracted for tendon inspection

Pellegrini, M.J. et al (2016). Effectiveness of Allograft Reconstruction Vs Tenodesis for Irreparable Peroneus Brevis Tears: A Cataveric Model. Foot and Ankle International, 37:8, pp. 803-808. Squires, N. et al (2007). Surgical Treatment of Peroneal Tendon Tears. Foot and Ankle Clinics of North America, 12, pp. 675-695. Peroneal Anastomosis

• Debridement/excision of all non viable tissue • Proximal tenodesis is placed at least 3-4 cm above the tip of the lateral malleolus • Distal tenodesis is placed at least 5-6 cm below the tip of the lateral malleolus • This is to avoid fibular impingement • Affix with 2-0 absorbable suture

Squires, N. et al (2007). Surgical Treatment of Peroneal Tendon Tears. Foot and Ankle Clinics of North America, 12, pp. 675-695. Peroneal Anastomosis

• Adjunctive procedures should accompany the tenodesis (address cause of tendon degeneration):

• Lateralizing calcaneal osteotomy • Lateral ankle ligamentous repair • Fibular groove deepening • Repair of torn or redundant superior peroneal retinaculum • De-bulking of low lying muscle belly if present

Cerrato, N. et al (2009). Peroneal Tendon Tears, Surgical Management and Its Complications. Foot and Ankle Clinics of North America, 14, pp. 299-312. Peroneal Anastomosis

• Post-op course: • Immobilization with NWB for 4-6 weeks • WB with CAM for 2-4 weeks • Transition to sneaker • PT ROM and strength training

Kim, D.H. et al (2006). Congenital Variation of the Peroneus Longus and Brevis Muscle-Tendon Units in Association with Peroneal Quartus: A Case Report. Foot and Ankle International, 27:10, pp. 847-848. Peroneal Anastomosis

• Outcomes in literature have generally been reported as favorable, with good patient satisfaction and reduction of pain • However, all studies are either small retrospective reviews or case studies (level 4 or 5 evidence)

Stamatis, E.D. et al (2014). Salvage Options for Peroneral Tendon Ruptures. Foot and Ankle Clinics of North America, 19, pp. 87-95. Literature Review

• After examining current literature on peroneal tenodesis, indication for tenodesis is questionable at best! • Nearly 50% or tenodesis patients did not return to full activity after 1 year! • 2/3rds of the patient reported activity related pain • It would seem the preservation of a functional muscle-tendon unit is an important principle in peroneal tendon repair

Stamatis, E.D. et al (2014). Salvage Options for Peroneral Tendon Ruptures. Foot and Ankle Clinics of North America, 19, pp. 87-95. Literature Review

• Pellegrini et al examined the effect of the tenodesis vs. allograft repair in a cadaveric model • Evidence for currently accepted peroneal repair is scant • No evidence that tenodesis restores normal biomechanics

Pellegrini, M.J. et al (2016). Effectiveness of Allograft Reconstruction Vs Tenodesis for Irreparable Peroneus Brevis Tears: A Cataveric Model. Foot and Ankle International, 37:8, pp. 803-808. Literature Review • 10 cadaveric lower limbs • Jig was used to hold limb and apply force to peroneal tendons proximally • Implanted strain gauge into both peroneals near insertion • Physiologic tension was applied in a series of foot positions • This was then compared to peroneal brevis to longus tenodesis, followed by peroneal brevis tendon allograft using semitendinosus

• Pellegrini et al concluded peroneal allograft repair better restored peroneal tendon tension when under anatomic load • Since tenodesis does not restore proper peroneal tension, clinical biomechanical foot imbalance is likely to result

• Pellegrini et al also looked at the potential of peroneal tenodesis reversal using allograft should tenodesis clinically fail • Case report • 41 yo female 9 months s/p peroneal tenodesis • Persistent pain despite PT and conservative treatments • MRI revealed failing tenodesis and also longitudinal tears of the peroneal longus with intersubstance degeneration

• Allograft repair with semitendinosus of both peroneal tendons • Deepening of fibular groove • Debulking of enlarged peroneal tubercle • Debulking of low lying muscle belly*

• 17 months post revision, patient was able to resume previous activity level • Significant reduction in pain

Pellegrini, M.J. et al (2014). Reversal of Peroneal Tenodesis With Allograft Reconstruction of the Peroneus Brevis and Longus: Case Report and Surgical Technique. Foot and Ankle Specialists, 7:4, pp. 327-331. Summary • Peroneal tendon injuries are not super common, with isolated PB injury being the most common of them (between a rock and a hard place) • Identification of injury is made with MRI, but extent of injury is generally made intraoperatively • Treatment options are dictated by assessing grade of injury, with grade/stage 2 correlating with tenodesis

Stamatis, E.D. et al (2014). Salvage Options for Peroneral Tendon Ruptures. Foot and Ankle Clinics of North America, 19, pp. 87-95. Filiatrault, A.D. et al (2015). Peroneus Longus Tendon Rupture Repair: Case Presentations. The Podiatry Institute Chapter Update, 32, pp. 167-173. Kim, D.H. et al (2006). Congenital Variation of the Peroneus Longus and Brevis Muscle-Tendon Units in Association with Peroneal Quartus: A Case Report. Foot and Ankle International, 27:10, pp. 847-848. Summary of Tenodesis

• HOWEVER, there is little evidence backing this salvage procedure • While tenodesis is a relatively easy procedure that has been utilized for many years, it may NOT be advantageous for the patient • There is no evidence that tenodesis restores anatomic or biomechanical function

Pellegrini, M.J. et al (2016). Effectiveness of Allograft Reconstruction Vs Tenodesis for Irreparable Peroneus Brevis Tears: A Cataveric Model. Foot and Ankle International, 37:8, pp. 803-808. Pellegrini, M.J. et al (2014). Reversal of Peroneal Tenodesis With Allograft Reconstruction of the Peroneus Brevis and Longus: Case Report and Surgical Technique. Foot and Ankle Specialists, 7:4, pp. 327-331. Becker, H.P. et al (1996). Functional Disorders of the Foot After Tenodesis: Is the Method Still Currently Acceptable? Sportverletz Sportschanden, 10:4, pp. 94-99. Conclusion of Tenodesis • More research is needed to determine if the tenodesis is indicated for specific situations (ie cavus foot type with a plantar flexed 1 st ray) • Consequences of the tenodesis include lack of stability, scarring of the tendon, and injury to adjacent tendon • Consider allograft direct peroneal repair, especially in the young or active individual • Consider adjunctive procedure (removal or peroneal quartus, peroneal groove deepening, reduction of cavus deformity, etc) Molloy, R. et al (2003). Failed Treatment of Peroneal Tendon Injuries. Foot and Ankle Clinics of North America, 8, pp. 115-129. Slater, H.K (2007). Acute Peroneal Tendon Tears. Foot and Ankle Clinics of North America, 12, pp. 759-674. Pellegrini, M.J. et al (2016). Effectiveness of Allograft Reconstruction Vs Tenodesis for Irreparable Peroneus Brevis Tears: A Cataveric Model. Foot and Ankle International, 37:8, pp. 803-808. Pellegrini, M.J. et al (2014). Reversal of Peroneal Tenodesis With Allograft Reconstruction of the Peroneus Brevis and Longus: Case Report and Surgical Technique. Foot and Ankle Specialists, 7:4, pp. 327-331. Conclusion of Peroneal Pathology in General: • Peroneal tendon pathology correction does NOT need to be a daunting procedure. • Tends to have good outcomes with ‘less is more’ approach. • Less suture in tendon, less damage to fibula, quicker rehab and better outcomes. Works Cited

• J Foot Ankle Surg. 2009 Mar-Apr;48(2):277-80. doi: 10.1053/j.jfas.2008.10.006. Epub 2009 Jan 9. A simplified technique for repair of recurrent peroneal tendon subluxation. Smith SE 1, Camasta CA , Cass AD .

• J Pediatr Orthop. 2010 Dec;30(8):899-903. doi: 10.1097/BPO.0b013e3181fbfcea. Preliminary results of calcaneofibular ligament transfer for recurrent peroneal subluxation in children andadolescents. Boykin RE 1, Ogunseinde B, McFeely ED , Nasreddine A, Kocher MS .

• J Foot Ankle Surg. 2001 Jul-Aug;40(4):252-63. Fibular groove deepening for recurrent peroneal subluxation. Mendicino RW 1, Orsini RC , Whitman SE , Catanzariti AR .

• J Bone Joint Surg Am. 2009 Mar 1;91 Suppl 2 Pt 1:146-55. doi: 10.2106/JBJS.H.01356. Intrasheath subluxation of the peroneal tendons. Surgical technique. Raikin SM 1.

• Foot Ankle Int. 2005 Jun;26(6):442-8. The peroneal groove deepening procedure: a biomechanical study of pressure reduction. Title CI 1, Jung HG , Parks BG , Schon LC .

• J Foot Ankle Surg. 2010 May-Jun;49(3):238-41. doi: 10.1053/j.jfas.2010.02.007. Epub 2010 Mar 28. Peroneal subluxation: surgical results in 31 athletic patients. Saxena A1, Ewen B.

• J Foot Ankle Surg. 1997 Mar-Apr;36(2):141-5. Peroneal subluxation: a comprehensive review of the literature with case presentations. Niemi WJ 1, Savidakis J Jr , DeJesus JM .

• Foot Ankle Int. 2005 Jun;26(6):436-41. Peroneal tendon subluxation in athletes: fibular groove deepening and retinacular reconstruction. Porter D1, McCarroll J, Knapp E , Torma J.

• Skeletal Radiol. 2013 Dec;42(12):1703-9. doi: 10.1007/s00256-013-1725-1. Epub 2013 Sep 21. Peroneal tendon abnormalities in subjects with an enlarged peroneal tubercle. Taneja AK 1, Simeone FJ , Chang CY , Kumar V , Daley S , Bredella MA , Torriani M.

• Sports Med. 2006;36(10):839-46. Recurrent subluxation of the peroneal tendons. Ferran NA 1, Oliva F, Maffulli N. • Foot Ankle Int. 2014 May;35(5):496-503. doi: 10.1177/1071100714523271. Epub 2014 Mar 17. Sliding fibular graft repair for the treatment of recurrent peroneal subluxation. Zhenbo Z1, Jin W , Haifeng G, Huanting L, Feng C, Ming L .

• Radiology. 2007 Jan;242(1):252-7. Peroneal tendon subluxation and dislocation: detection on volume-rendered images--initial experience. Ohashi K1, Restrepo JM , El-Khoury GY , Berbaum KS . Additional Works Cited

• Arrowsmith et al., 1983. Arrowsmith SR, Fleming LL, Allman FL: Traumatic dislocations of the peroneal tendons. Am J Sports Med 1983; 11:142-146. Study of the alternative surgical technique that directly deepened the groove after an osteochondral flap was elevated. (Level IV evidence [case series]) • Davis et al., 1994. Davis WH, Sobel M, Deland J, Bohne WH, Patel MB: The superior peroneal retinaculum: an anatomic study. Foot Ankle Int 1994; 15:271-275. Anatomic study of the superior peroneal retinaculum and its variable insertions. • Edwards, 1988. Edwards M: The relations of the peroneal tendons to the fibula. Am J Anat 1988; 42:213-253. Anatomic study of the peroneal tendons' course along the fibula. • Karlsson et al., 1996. Karlsson J, Eriksson BI, Swärd L: Recurrent dislocation of the peroneal tendons. Scand J Med Sci Sports 1996; 6:242-246. Case series (15 patients) of the alternative surgical technique that directly deepened the groove after an osteochondral flap was elevated. (Level IV evidence [case series]) • Kollias and Ferkel, 1997. Kollias SL, Ferkel RD: Fibular grooving for recurrent peroneal tendon subluxation. Am J Sports Med 1997; 25:329-335. Case series (11 patients) of the alternative surgical technique that directly deepened the groove after an osteochondral flap was elevated. (Level IV evidence [case series]) • McGarvey and Clanton, 1996. McGarvey W, Clanton T: Peroneal tendon dislocations. Foot Ankle Clin 1996; 1:325-342. Review article of 265 reported cases in the literature. (Level III evidence) • Mendicino et al., 2001. Mendicino RW, Orsini RC, Whitman SE, Catanzariti AR: Fibular groove deepening for recurrent peroneal subluxation. J Foot Ankle Surg 2001; 40:252- 263. The first publication of the surgical technique using indirect groove deepening for chronic peroneal dislocation/subluxation. • Ogawa et al., 2007. Ogawa BK, Thordarson DB, Zalavras C: Peroneal tendon subluxation repair with indirect fibular groove deepening technique. Foot Ankle Int 2007; 28:1194- 1197. Case series (15 patients) of the indirect fibular groove deepening technique. (Level IV evidence [case series]) • Shawen and Anderson, 2004. Shawen SB, Anderson RB: Indirect groove deepening in the management of chronic peroneal tendon dislocation. Tech Foot Ankle Surg 2004; 3:118- 125. The surgical technique of indirect groove deepening is presented, with a brief review of preliminary results. (Level IV evidence)