The Utility of Knee Releases in Arthrogryposis

Background: Knee contractures are difficult deformities to manage in arthrogryposis. There is little information regarding the long-term functional outcomes. Methods: Patients with a diagnosis of arthrogryposis who had knee releases performed at a single institution with at least 2 years of follow-up were identified retrospectively. Patients were called back prospectively for a clinical examination and administration of the Pediatric Outcomes Data Collection Instrument (PODCI), Pediatric Evaluation of Disability Inventory (PEDI), and the WeeFIM instruments. Functional mobility was quantified using the Functional Mobility Scale (FMS). Results: Thirty-two patients were identified with a total of 50 knees. There were 45 flexion contractures and 5 extension contractures. Average length of follow- up was 11.9 years ( range, 2.2-23.6 years). Amount of extension on final follow- up correlated with all final FMS scores (P < 0.02). The FMS demonstrated decreases in mobility as distance increased. Twenty-two of 32 patients completed functional outcomes measures. Pediatric Evaluation of Disability Inventory Mobility scores, Functional Independence Measure for Children ( WeeFIM) Mobility, and WeeFIM Self-Care scores were decreased compared with norms, and Normative PODCI scores at final follow-up showed significant impairment in Upper Extremity Function, Transfers/Mobility, Sports/Physical Function, and Global Function Domains. When patients were subdivided by length of follow- up, patients showed decline in scores for all FMS distances; PEDI Mobility Domains; WeeFIM Self-Care and Mobility Domains; and Transfer/Mobility, Sports/Physical Function, and Global Function Domains, as length of follow- up increased. Conclusions: Whereas knee releases may improve function in the short term, function and outcomes decline as patients age. Patients with arthrogryposis demonstrated significant impairment in normative scores for Upper Extremity/Physical Function, Transfers/Mobility, Sports/Physical Function, and Global Function Domains. In addition, function as measured by the PODCI, WeeFIM, and PEDI showed decreased scores as length of follow- up increased. We strongly advise that when counseling parents on this surgical intervention, parents are made aware that ambulatory ability may improve short term but may decline as patients age and contractures recur. Level of Evidence: Therapeutic Level 4