Outcome of Achilles tendon plication and transfer of peroneus longus to Achilles tendon for correction of dynamic calcaneo-valgus deformity of the foot in post-polio residual paralysis

Abstract

Objective: Tendon transfers are indicated when dynamic muscle imbalance results in a deformity that interferes with ambulation or function of the extremities. Foot and ankle are the most dependent parts of the body and are subjected to greater strain than other parts. Calcaneo-valgus deformity is one of the common deformities seen in Post-Polio Residual Paralysis. A host of operative procedures have been described in the management of this deformity. We report the results of the study conducted in our institute where Achilles tendon plication and transfer of Peroneus Longus tendon to Achilles tendon has been done for dynamic calcaneo-valgus deformity of the foot in patients of post-polio residual paralysis. Methods: This is a prospective study of 37 patients with Calcaneovalgus deformity having Post-Polio Residual Paralysis presenting to Balaji Institute of Surgery, Research and Rehabilitation for the Disabled Hospital from December 2009 to December 2012. Informed consent was taken from the parents of all the patients. Ethical committee approval was also taken. Patients with age more than 7 years, ability to walk without support and Peroneal tendon having minimum motor power of grade 4 or 5 as per MRC classification are included in our study. Patients with fixed deformity at ankle joint or subtalar joint are excluded from the study. Pre-operative evaluation included detailed motor examination of the involved lower limbs as per MRC (Medical research council) classification, evaluation of deformity in the hip and knee and range of motion at ankle. AOFAS (American Orthopaedic Foot and Ankle Society) clinical rating system was used to assess the patient pre-operatively and post-operatively. The aggregate score of the AOFAS ankle-hind foot clinical rating scale pre and post operatively were analyzed with use of chisquare analysis. The level of significance of < 0.05 was considered to be significant. The surgical procedure was done under spinal anesthesia with the patient in lateral position under pneumatic tourniquet. A longitudinal incision is made starting from the tip of lateral malleolus midway between the posterior border of lateral malleolus & Achilles tendon to about 8-10cm proximally. Skin flaps are mobilized without dissecting the subcutaneous fat. The two peroneal tendons are identified as they pass down the leg and around the back of the lateral malleolus. The peroneus longus tendon is divided as distally as possible and mobilized. Similarly the Achilles tendon is identified. Plication of the Achilles tendon is done in its middle third with nylon sutures and the peroneus longus tendon is transferred through it using Fish-Mouth (Pulvertaft) tendon suturing technique and is secured over itself proximally under tension providing the tenodesis effect. While this is done the ankle is kept in plantar flexion. The deep fascia is closed over the tendon. Pneumatic tourniquet was released, and the incision was closed in layers after hemostasis was achieved. Below knee cast is applied with the foot in plantar...