ABSTRACT
Purpose: The purpose of this study was to establish consensus for the assessment of foot alignment and function in ambulatory children with cerebral palsy, using expert surgeon's opinion through a modified Delphi technique. Methods: The panel used a five-level Likert-type scale to record agreement or disagreement with 33 statements regarding the assessment of foot alignment and function. Consensus was defined as at least 80% of responses being in the highest or lowest of two of the five Likert-type ratings. General agreement was defined as 60%-79% falling into the highest or lowest two ratings. There was no agreement if neither threshold was reached. Results: Consensus was achieved for 25 (76%) statements, general agreement for 4 (12%) statements, and lack of consensus for 4 (12%) of the statements. There was consensus that the functional anatomy of the foot is best understood by dividing the foot into three segments and two columns. Consensus was achieved concerning descriptors of foot segmental alignment for both static and dynamic assessment. There was consensus that radiographs of the foot should be weight-bearing. There was general agreement that foot deformity in children with cerebral palsy can be classified into three levels based on soft tissue imbalance and skeletal malalignment. Conclusion: The practices identified in this study can be used to establish best care guidelines, and the format used will be a template for future Delphi technique studies on clinical decision-making for the management of specific foot segmental malalignment patterns commonly seen in children with cerebral palsy. Level of Evidence: V.
ABSTRACT
BACKGROUND: Constrained acetabular components have been used to treat hips with recurrent instability following total hip arthroplasty and hips that demonstrate instability during revision surgery. In such hips, when a secure cementless acetabular shell is present, the surgeon can cement a constrained liner into the existing shell. The purpose of this study was to evaluate the clinical and radiographic outcome of this technique with use of a tripolar constrained liner that was cemented into a well-fixed cementless acetabular shell. METHODS: Between 1988 and 2000, constrained liners were cemented into thirty-one well-fixed cementless acetabular shells at three centers. The average age of the patients at the time of the index surgery was 72.1 years, and the indications for the procedure were recurrent hip instability in sixteen hips and intraoperative instability in fifteen hips. The patients were evaluated with respect to the clinical outcome and radiographic evidence of shell loosening and osteolysis. RESULTS: At an average duration of follow-up of 3.9 years, twenty-nine liners (94%) were securely fixed in the cementless shells and two constrained liners had failed. One liner failed because it separated from the cement, and one failed because of fracture of the capturing mechanism. Both hips were successfully revised with another cemented tripolar constrained liner. No acetabular component demonstrated radiographic evidence of progressive loosening or osteolysis. CONCLUSIONS: A constrained tripolar liner cemented into a secure, well-positioned cementless acetabular shell provides stability and durability at short-term follow-up. Careful attention to the preparation of the liner, the sizing of the component, and the cementing technique are likely to reduce the failure of this construct, which can be used for difficult cases of total hip instability.
