Association of Leg Length and Femoral Offset Restoration With Functional Outcomes After Primary Total Hip Arthroplasty

Abstract

Background: Restoration of leg length and femoral offset is an important primary total hip arthroplasty (THA) goal but their relationship with postoperative functional outcome is not completely understood.

Objective: To explore the relationship between femoral offset, restored leg length and functional outcome after primary THA.

Material and Methods: This is a prospective observational analytical study conducted in the department of orthopaedics, Hayatabad Medical Complex, Peshawar from April 2022 to September 2022. Through consecutive sampling a total of 120 patients undergoing primary unilateral THA were included. Leg length and femoral offset were measured on the preoperative and the postoperative radiographs. The Harris Hip Score (HHS) was used to assess functional outcome pre- and 6 months following surgery. Descriptive and inferential statistics were carried out, such as correlation and multiple linear regression analysis.

Results: The mean age was 55.8 ± 10.7 years. Mean HHS improved from 45.7 ± 8.6 preoperatively to 86.9 ± 8.7 at six months (p < 0.001). Patients with leg-length restoration < 5 mm showed a significantly higher HHS than patients with a larger discrepancy (89.2 ± 6.9 vs. 81.8 ± 9.8; p < 0.001).Patients with a leg-length restoration of less than 5 mm had a significantly higher HHS than those with a greater discrepancy (89.2 ± 6.9 vs. 81.8 ± 9.8; p < 0.001). The same results were seen for the femoral offset restoration. The two variables were both separately correlated with postoperative HHS.

Conclusion: Restoration of leg length and femoral offset with accuracy was correlated to functional results after primary THA.

Keyword: Total Hip Arthroplasty (THA), Leg Length Restoration (LLR), Femoral Offset.