ABSTRACT
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.
ABSTRACT
BACKGROUND: Several methods are available to estimate leg lengths at maturity to facilitate the determination of timing of epiphysiodesis. We compared the Paley multiplier, Sanders multiplier, and White-Menelaus methods in an epiphysiodesis-aged cohort. We assessed intra- and interrater reliability for Sanders skeletal stages and Greulich and Pyle atlas skeletal age. METHODS: Actual growth was recorded in healthy, unoperated femoral and tibial segments from an epiphysiodesis database. The predicted and actual lengths were compared with use of the Paley multiplier and White-Menelaus methods, Greulich and Pyle skeletal age, and the Sanders multiplier using Sanders stages. Intra- and interrater reliability were assessed in a separate group of 76 skeletal age films. RESULTS: The cohort included 148 femora and 195 tibiae in 197 patients. Femoral length at maturity was slightly underestimated by the Sanders multiplier and staging, was overestimated by the Paley multiplier and skeletal age, and was most accurately predicted with use of the White-Menelaus formula and skeletal age. All methods overestimated tibial length at maturity. The whole-leg prediction accuracy of the Sanders multiplier and White-Menelaus formula were comparable and were more accurate than that of the Paley multiplier. For Sanders skeletal staging, the interrater reliability varied from 0.86 to 0.88 and the intrarater reliability varied from 0.87 to 0.96. For Greulich and Pyle skeletal age, the interrater reliability varied from 0.87 to 0.89 and the intrarater reliability varied from 0.91 to 0.95. CONCLUSIONS: Use of the Sanders multiplier and skeletal stages was more accurate than the Paley multiplier and skeletal age in this cohort. Use of the White-Menelaus formula and skeletal age was slightly more accurate in predicting femoral length and slightly less accurate in predicting tibial length compared with the Sanders multiplier. Intra- and interrater reliability were similar between Sanders skeletal stages and Greulich and Pyle atlas skeletal age. The White-Menelaus formula and skeletal age was the recommended method for predicting lower-extremity segment lengths at maturity and epiphysiodesis effect. Although easier to recall without referencing an atlas and not sex-specific, Sanders skeletal staging does not correspond directly to years of growth remaining, and thus cannot be used with the White-Menelaus formula. CLINICAL RELEVANCE: The Greulich and Pyle atlas to determine skeletal age and the White-Menelaus formula to determine growth remaining are reliable predictors of epiphysiodesis effect in the lower extremities.
