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Risk factors for hip redislocation in surgically treated children with cerebral palsy: A multicenter study with
Rafik Ramazanov1, Ulaş Can Kolaç2, Evren Akpinar3
1Children's Ortho and Spine Center, Ankara, Turkey.
Insights
Younger age at surgery and specific radiographic measurements predict hip redislocation in children with cerebral palsy (CP) after surgery. A new model helps stratify risk for better patient management.
Area of Science:
- Orthopedic surgery
- Pediatric orthopedics
- Cerebral palsy research
Background:
- Hip dislocation is a common complication in children with cerebral palsy (CP).
- Surgical treatment aims to correct hip dislocation but carries a risk of redislocation.
Purpose of the Study:
- To identify clinical and radiographic risk factors for hip redislocation in pediatric CP patients post-surgery.
- To develop a predictive model for hip redislocation risk stratification.
Main Methods:
- Multicenter retrospective study of 115 children with CP undergoing hip reconstructive osteotomy.
- Evaluation of demographic, clinical, and radiographic variables.
- Logistic regression and classification and regression tree (CART) analysis to identify risk factors and stratify risk.
Main Results:
- Hip redislocation occurred in 21.7% of cases.
- Younger age at surgery, higher postoperative Sharp's angle, and lower Mose hip ratio (MHR) were independent predictors of redislocation.
- The CART model identified specific thresholds for surgical age, Sharp's angle, and MHR to classify patients into high- and low-risk groups.
Conclusions:
- Younger surgical age and indicators of insufficient hip correction (high Sharp's angle, low MHR) are associated with increased redislocation risk.
- Radiographic parameters like MJS/CJS and MJS/MCFED ratios also correlate with redislocation, suggesting incomplete reduction.
- A clinically applicable decision-tree model using radiographic parameters can predict redislocation risk after CP hip reconstruction.
Purpose:
To identify clinical and radiographic risk factors associated with hip redislocation in children with cerebral palsy (CP) who underwent surgical treatment for hip dislocation.
Methods:
This multicenter retrospective study included children with CP who underwent reconstructive osteotomy for hip dislocation and were followed until triradiate cartilage closure. Demographic, clinical, and radiographic variables were evaluated. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors for redislocation. Additionally, a classification and regression tree (CART) model was developed to stratify redislocation risk.
Results:
Hip redislocation occurred in 25 of 115 hips (21.7%). Redislocation was significantly more frequent in hips treated with femoral osteotomy alone (40%) compared to combined femoral and pelvic osteotomies (16.7%), (p = 0.026). Multivariate analysis identified younger age at surgery (Odds ratio (OR) = 0.981, p = 0.010), higher postoperative Sharp's angle (OR = 1.082, p = 0.034), and lower postoperative Mose hip ratio (MHR) (OR = 0.007, p = 0.033) as independent predictors of redislocation. Radiographic ratios, including medial joint space to cranial joint space (MJS/CJS) and MJS to maximum capital femoral epiphysis diameter (MJS/MCFED), were also significantly higher in redislocated hips. The CART model classified patients into high- and low-risk groups based on surgical age ≤76 months, postoperative Sharp's angle ≥48°, and MHR < 0.69.
Conclusions:
Younger surgical age, insufficient correction as indicated by a higher postoperative Sharp angle and lower MHR were independently associated with hip redislocation in CP patients undergoing surgery. MJS/CJS and MJS/MCFED ratios were also associated with redislocation, indicating incomplete reduction.
Significance Of Study:
This study presents a clinically applicable decision-tree model to predict redislocation risk after CP hip reconstruction using radiographic parameters.
Level Of Evidence:
Level III, multicenter retrospective study.
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