Femoral nerve palsy is a mythic complication of Pavlik harness treatment for developmental dysplasia of the hip

Abstract

Introduction Femoral nerve palsy (FNP) is reported as a potential complication of Pavlik harness treatment for developmental dysplasia of the hip (DDH). It is known to be transient, as it often resolves following strap adjustment to decrease hip flexion, which may jeopardize the treatment success. The purpose of this study was to report the incidence of this potential complication, to identify any possible associated risk factors and to evaluate its outcome without any specific strap release. Materiel et methodes A retrospective chart review was conducted on all DDH patients who underwent Pavlik harness treatment for DDH between August 1997 and June 2015 by a single physician. Our treatment protocol includes biweekly visits to the clinic for strap adjustment and evaluation of bilateral active knee extension as an indirect indicator of femoral nerve palsy during the entire treatment duration, 3 months in average. Femoral nerve palsy (FNP) was defined as a partial or total deficit in active knee extension anytime during or following the completion of Pavlik harness treatment. All cases of femoral nerve palsy were identified and reviewed. In unilateral cases, the DDH hip was compared to the non-affected side. All hips with femoral nerve palsy were compared to the remaining hips of the series and any possible risk factor for paralysis was recorded, including age, patient's size, severity according to Tonnis and hip flexion angle in the harness. Statistical analysis was undertaken. Resultats Fifty-three cases of femoral nerve palsy of various severity were identified from a group of 473 children with 527 hips treated for DDH (10%) at an average age of 3.9 months. Ninety-three percent of them presented during the first 2 weeks of treatment. FNP was more common in older and larger children with the most severe Tonnis type and a hip flexion angle in the harness above 90 degrees (P  Discussion FNP is a fairly common complication of Pavlik harness treatment for DDH. It is most observed in higher Tonnis types, but its presence by itself is not predictive of treatment failure. The most significant risk factors for FNP seem to be DDH severity and hip flexion angle in the harness. FNP resolves spontaneously before completion of treatment without any specific measures and therefore does not require any strap release or harness discontinuation.