Surgical Treatment of Severe Cavovarus Foot Deformity in Charcot-Marie-Tooth Disease

INTRODUCTION: A successful adjusted treatment algorithm for the correction of cavovarus foot deformity requires soft-tissue balancing procedures, in particular total split posterior tibial tendon transfer (T-SPOTT), in combination with adjunctive corrective procedures depending on the degree of deformity. STEP 1: SURGICAL PREPARATION: Place the patient in a supine position and follow a standard aseptic surgical disinfection and draping protocol, allowing access to the iliac crest. STEP 2: STEINDLER RELEASE OF THE PLANTAR APONEUROSIS: Use a medial approach to access and transect the plantar aponeurosis. STEP 3: RELEASE THE POSTERIOR TIBIAL TENDON AT THE FOOT: Transect the posterior tibial tendon near its insertion point. STEP 4: RETRACT AND SPLIT THE POSTERIOR TIBIAL TENDON AT THE CALF AND TRANSFER IT THROUGH THE INTEROSSEOUS MEMBRANE: Make a medial incision in the distal part of the calf, retract the posterior tibial tendon (and flexor digitorum tendon if necessary), split it longitudinally in half, and pass it through the interosseous space. STEP 5: REVEAL THE TARGET TENDONS AND PULL THE POSTERIOR-TIBIAL-TENDON HALVES TO THESE TENDONS: Expose the anterior tibial and peroneal tendons and pull the posterior-tibial-tendon halves (and flexor digitorum longus tendon of it is being used) to these tendons. STEP 6: CHOPART, OR TRIPLE OR LAMBRINUDI, ARTHRODESIS: Perform a Chopart, or triple or Lambrinudi(16), arthrodesis when osseous correction and stabilization are required for fixed deformities. STEP 7: MODIFIED JONES PROCEDURE: If the cavovarus foot displays flexible clawing of the big toe, carry out a modified Jones procedure. STEP 8: EXTENSION OSTEOTOMY OF THE FIRST METATARSAL: If the first metatarsal remains in a fixed plantar flexed position and cannot be corrected with the Jones procedure, perform a dorsal-based wedge extension osteotomy. STEP 9: CLAWING OF THE LESSER TOES: Incise the plantar tendons, transect the long flexor tendons, and place a single Hohmann wire through the end of each claw toe. STEP 10: SOFT-TISSUE EQUINUS CORRECTION (RARELY NEEDED): Depending on the severity of the remaining equinus, correct it with calf muscle or calcaneal tendon lengthening (the more severe the equinus, the more distal the corrective measure). STEP 11: SUPRAMALLEOLAR VARUS DEROTATION OSTEOTOMY: If foot external rotation is increased after foot correction, supramalleolar derotation osteotomy should be added to avoid lever-arm problems postoperatively. STEP 12: COMPLETE THE TENDON TRANSFERS: Attach the transferred tendons to their respective target tendons using a Pulvertaft needle with a Pulvertaft weave technique, while keeping the foot in a plantigrade position. STEP 13: WOUND CLOSURE: Reevaluate the foot and determine if all corrections have been made, perform necessary final radiographic documentation, release the tourniquet, perform hemostasis, clean the wounds, and close them. STEP 14: POSTOPERATIVE MANAGEMENT AND AFTERCARE: The achieved operative correction is only as good as the postoperative treatment allows. RESULTS: Various authors have recommended posterior tibial tendon transfer to the dorsum of the foot to correct foot drop. Indications Contraindications Pitfalls & Challenges