Long-term Outcomes of Surgically Treated Congenital Dislocation of the Knee.

BACKGROUND: Congenital dislocation of the knee (CDK) may be idiopathic or associated with another condition, such as Larsen syndrome or arthrogryposis. Surgical reduction of type-3 dislocation may require quadricepsplasty (QP) or femoral diaphyseal shortening (FS). Because it is unknown which treatment is more effective, we evaluated long-term outcomes using patient-reported questionnaires and gait analysis, comparing results by surgery type and underlying diagnosis. METHODS: Twelve patients (mean age, 19 mo) were treated surgically for CDK from 1985 to 2015 and studied 9 to 30 years postoperatively. Three participants had idiopathic CDK, 5 had Larsen syndrome, and 4 had arthrogryposis. Eleven knees underwent QP and 7 underwent FS. Participants were evaluated in our movement science laboratory and completed patient-reported outcome questionnaires. Data were compared with healthy, age-matched control values at the same visit. RESULTS: Surgically treated knees had less flexion during swing ( P <0.01), less overall motion ( P <0.01), greater coronal instability ( P <0.04), and slower gait ( P <0.01) compared with controls. QP knees had more instability in midstance ( P =0.03) and less flexion during gait compared with FS knees, less sagittal power generation than controls ( P <0.01), and trended toward lower scores on Knee Injury and Osteoarthritis Outcome and Lysholm Knee Questionnaires than FS patients did. The idiopathic group had the gait most similar to that of controls, followed by the Larsen syndrome group and then the arthrogryposis group. The idiopathic group also had a better UCLA Activity Score ( P =0.03) than the arthrogryposis group did. CONCLUSIONS: Surgical treatment of type-3 CDK will not likely restore normal knee function, suggesting teratologic joint abnormality. In this small series, FS produced better gait mechanics and patient-reported outcomes compared with QP. Not surprisingly, patients with idiopathic CDK had better outcomes than those with a syndromic diagnosis, likely related to having only a single joint affected. LEVEL OF EVIDENCE: Level III.

Clinical and Radiographic Assessment of Adult Function After Blount Disease in Childhood: An Exercise in Futility.

BACKGROUND: Few studies evaluate long-term function of patients with Blount disease. We sought to document patient radiographic and functional status 20 to 30 years after sugical treatment for infantile or adolescent Blount disease. METHODS: We reviewed the medical records and radiographs of patients operated at our institution for Blount disease between 1985 and 1995. Over a 4-year period, we recruited subjects for an IRB-approved call-back study. RESULTS: One hundred five patients were eligible for the call-back study. Thirty-one (30%) had a criminal record, 18 of sufficient gravity to preclude invitation to return. Of the remaining 87, 40 (46%) could not be contacted. Of 47 with valid contact information, 10 (21%) were reported as deceased (although this could not be objectively confirmed), 20 (43%) did not respond or failed to show for assessment, and 1 (2%) declined to participate. 16 subjects returned at average age 36, 22 to 31 years post-index surgery. Body mass index (BMI) averaged 45.8 (range 23.9 to 67.6). Physical Score correlated most strongly and inversely with BMI ( P <0.01). Satisfaction with life correlated strongly and inversely with mechanical axis deviation ( P =0.02) and radiographic osteoarthritis of the knee ( P =0.02), but not BMI. There also was no correlation between severity of radiographic osteoarthritis and mechanical axis deviation ( P =0.46) or BMI ( P =0.52). CONCLUSIONS: The small fraction of patients returning for evalutation minimize clinical conclusions that can be drawn from this study, despite an intensive 4-year effort to conduct it. Management of obesity and other socioeconomic characteristics are likely the most important aspects of treatment of patients with Blount disease. Our primary conclusion is that meaningful long-term functional studies of pediatric orthopaedic conditions will not be answered by retrospective call-back studies, and must be conducted within prospective registries and regular longitudinal follow-up. LEVEL OF EVIDENCE: III-Case-controlled study.