Congenital dislocation of the knee at birth – Part 2: Impact of a new classification on treatment strategies, results and prognostic factors

IntroductionAn original classification of congenital dislocation of the knee (CDK) was drawn up, based on neonatal semiology. The objective of the present study was to assess impact on treatment decision-making and prognosis.Material and methodsFifty-one CDKs in 40 patients were classified neonatally into 3 types: I, reducible (n = 28); II, recalcitrant (n = 16); and III, irreducible (n = 7). Number of anterior skin grooves, range of motion (RoM), flexion deficit and reduction stability were recorded. Depending on reducibility, treatment comprised: physiotherapy with splints, traction with cast immobilization, or surgery. At follow-up, knees were assessed in terms of RoM and stability.ResultsMean age at first consultation was 5.6 days (range: 0–30). Mean age at follow-up was 9 years (range: 1–26). Physiotherapy with splinting achieved stable reduction in all type-I knees. Five type-II knees (31%) required traction, none of which needed surgery. Four type-III knees (57%) required surgery. Outcome was good or excellent in 82% of type-I knees, good in 68% of type II and poor in all type-III knees.ConclusionThe study confirmed the relevance of the present neonatal classification to treatment, with increasing rates of surgical indication and decreasing rates of satisfactory outcome from types I to III. Therapeutic attitude can be graded according to severity of CDK.Level of evidenceIV, single-center retrospective series.