Long-Term Follow-Up of Management of the Hypoplastic Femur With Femoral Episiotomy and Onlay Allograft During Total Hip Arthroplasty

Background: To insert the regular-sized stem for a dysplastic femoral canal, controlled episiotomy of the femur can be performed. The purpose of this study is to determine the long-term (up to 19 years) results of total hip arthroplasties (THAs) using strut allografts combined with an episiotomy over an extensively porous-coated stem. Methods: We reviewed the results of 65 total hip arthroplasties in 63 patients (mean age 42.1 years; range 21-61) with dysplastic femur after childhood sepsis. The patients were treated using controlled episiotomy of the femur to widen the femoral canal, extensively porous-coated femoral stems, and cortical strut allografts because primary axial or rotational stability could not be achieved without grafting. The mean follow-up was 17.1 years (range 15-19). Results: The mean Harris Hip Score at the final follow-up was 85 ± 15 points (range 45-100). The mean Western Ontario and McMaster Universities Osteoarthritis Index score was 23 ± 15 points (range 13-53). The mean University of California, Los Angeles score was 6.3 points (range 5-8). A Kaplan-Meier survivorship analysis at 19 years of follow-up showed that the survival rate of the femoral components was 92% (95% confidence interval 89-98), and it was 88% (95% confidence interval 85-92) for the acetabular component with aseptic loosening or revision for any reason. Conclusion: We found good results in terms of longevity and functional outcome using this technique. Future mechanical studies, in addition to controlled clinical studies, are warranted.