Ambulation gains after knee surgery in children with arthrogryposis

Background: Arthrogryposis multiplex congenita is a rarecongenital disorder associated with multiple musculoskeletalcontractures that causes substantial morbidity. Knee involve-ment is commonly seen among children with arthrogryposis,with flexion contracture of the knee being the most frequentknee deformity. Knee flexion contractures in the pediatricpopulation are particularly debilitating as they affect ambula-tion. Treatment for knee flexion contractures requires numerousorthopaedic procedures and an extensive follow-up period. Thepurpose of this study was to assess the effectiveness of orthopaedicprocedures, namely distal fem oral supracondylar extensionosteotomy and/or Ilizarov external fixator, on the ambulationstatus of children with knee flexion contracture and whether anyfunctional gains are maintained at the latest follow-up.Methods: All children with arthrogryposis followed at ourinstitution who had surgical correction for knee flexioncontractures were included in this study. Fourteen patients wereidentified and their medical records were reviewed. The etiologyfor all patients was amyoplasia. The mean age at first surgerywas 7.0 years (range, 2 to 16y). The mean length of follow-upwas 59.3 months (range, 12 to 117mo). Contractures weretreated with femoral extension osteotomy (n=8), Ilizarovexternal fixator (n=1), or both (n=5). Three patients earlierhad posterior soft tissue releases, including hamstrings lengthen-ings, proximal gastrocnemius release, and release of posteriorcapsule.Results: Preoperatively, 11 patients were nonambulatory, 2patients were household ambulators, and 1 patient walked withorthoses in the community. There was an average of 1.8 kneesurgeries done per patient, namely distal femoral extensionosteotomy and/or Ilizarov external fixator. At the latest follow-up, 8 patients were ambulatory with technical aids (orthosis,walker, braces, or rollator walker), 2 patients were householdambulators, 1 patient used a wheelchair but was independent fortransfers, and 3 patients remained nonambulatory. The meanflexion contracture before the first surgery was 63.7±26.8degrees. Postoperatively, the mean flexion contracture was13.2±16.7 degrees. At the latest follow-up, the mean flexioncontracture was 34.0±24.1 degrees. There were complicationsin 2 patients, including infected hardware which resolved withantibiotic treatment, and neurologic compromise which resolvedon its own.Conclusions: Surgical correction of knee flexion deformities bydistal femoral extension osteotomy and/or Ilizarov externalfixator was effective in improving the ambulation status ofchildren with arthrogryposis. At latest follow-up, the gradualloss of total arc of motion and the recurrence of knee flexioncontractures did not limit the ambulatory gains achieved.Level of Evidence: IV, Case series.Key Words: arthrogryposis, knee flexion contractures, distalfemoral extension(J Pediatr Orthop 2010;30:863–869)