Hamstring transfer for quadriceps paralysis in post polio residual paralysis

CONTEXT: Paralysis of quadriceps muscle leads to severe disability as the knee is unstable and cannot be fully extended and locked in extension, which results in giving way of the knee joint. Because of this, the patient tries to get stability of the knee by various means like hand to knee gait, extreme internal or external rotation of the affected limb to stabilize knee by support of medial or lateral collateral ligament, respectively, or by tilting pelvis. When there is concomitant weakness of gluteus maximus quadriceps and hamstrings (MRC muscle power less than grade III), patient may develop compensatory hyperlordosis of spine. Hamstring (H) transfer is a well-accepted procedure for patients with quadriceps (Q) weakness. For hamstring transfer, we have used a modified technique of anchoring of biceps femoris and semitendinosus tendon to patella. Instead of cutting the periosteum over the patella in an I-shaped manner, an osteoperisoteal flap was raised after two parallel incisions over the patella and both tendons were sutured under the flap with each other. We conducted a retrospective evaluation of the results of modified hamstring transfer in 267 patients of post polio residual paralysis with residual quadriceps paralysis. MATERIALS AND METHODS: Two hundred and fifty young patients (100 male and 150 female patients) who had quadriceps paralysis due to polio were managed by hamstring transfer at a single center between 1984 and 1996 and were followed for a mean of 5 years (range 4–12 years). Age of patients ranged from 7 to 18 years in 238 patients and 12 patients were above the age of 18 years. All cases were followed periodically, and assessment of knee extension, extension lag, knee flexion, elimination of calliper, and avoidance of hand to knee gait was done. RESULTS: One hundred and sixty two patients (65%) showed excellent results, 38 patients (15%) had good results, and 50 patients (20%) showed poor results. Ninety three patients had major complications like genu recurvatum, restricted knee flexion, and extension lag. Ten patients had minor complications like superficial infection and epidermal edge necrosis. CONCLUSIONS: H to Q transfer in the presence of quadriceps paralysis with good power in hamstring is a better alternative than supracondylar osteotomy because it is a dynamic correction and it produces some degree of recurvatum with increasing stability of knee in extension while walking. While inserting hamstring over patella the periosteum is not cut in an I-shaped fashion to create a flap which gives additional strength to new insertion and also patella act as a fulcrum during the extension of knee by producing the bowstring effect.