Outcomes of double-incision posterior knee release for severe knee flexion contracture

Abstract

Many surgical solutions for knee flexiondeformity in the pediatric population alter the anatomical bony alignment in the distal femur. Posterior knee capsule release has been presented as an alternative surgical procedurethat maintains the anatomical shape of relevant bones while solving the issue of knee flexion contracture. The aim of this study is to assess the results of a double-incision posteriorknee capsulotomy release performed on pediatric patients with neuromuscular or congenital severe knee flexion deformity. Thirty cases (24 patients, mean age 7.4 years) of severe knee flexion contractures were retrospectively analyzed in a cohort of varying underlying conditions (including spina bifida, muscular dystrophy, cerebral palsy, sclerodermia, and congenital patellar dislocations). Posterior knee release was performed through medial and lateral short incisions with subsequent serial casting. Range and pace of correction as well as the complication rate were recorded. Follow-up information (>1 year) included functionality (FMS scale) and pain (Kujala/Knee Injury Osteoarthritis Score [KOOS]) scales. Significant correction in the knee position was achieved in all analyzed knees (from mean 40.2° to 0.7°; P < 0.01). Twenty-nine out of 30 cases achieved correction by 7 days postoperatively (average number of casts: 1.93 ± 1.05). Overall complication rate in the analyzed cohort reached 6.7% (2/30 cases; double metaphyseal fracture and arthrofibrosis). At follow-up (22.3 months on average), functional ambulation and pain parameters improved drastically, with no further complications observed. Double-incision posterior knee release is an effective method of knee contracture release, which does not affect the axial alignment of the distal femoral bone. Thus, posterior knee release should be considered as potential alternatives to osteotomies and eight-plate corrections, which are currently the basic methods of knee contracture treatment.