Effect of Preoperative Leg Length Discrepancy on Functional Outcome and Patient Satisfaction After Total Hip Arthroplasty in Cases of Osteonecrosis of the Femoral Head.

BACKGROUND: Severe preoperative leg length discrepancy (LLD) can lead to poor preoperative functional status in patients with extensive osteonecrosis of the femoral head (ONFH). This study aimed to assess the effect of preoperative LLD on functional outcomes and patient satisfaction post-total hip arthroplasty (THA) in ONFH patients.

METHODS: Twenty-two patients with severe LLD (≥15 mm) and 44 patients with mild LLD (<15 mm) on preoperative radiographs were enrolled as the study group and control group, respectively. All 66 patients were diagnosed with unilateral ONFH. Patients' functional outcomes (Harris Hip Score [HHS], Oxford Hip Score [OHS], patient-perceived LLD, Visual Analogue Scale [VAS] pain score, and Limping Assessment]) and satisfaction (self-administered patient satisfaction scale) were evaluated at 3 and 12 months after THA.

RESULTS: At 3 months after THA, the study group had poorer outcomes in terms of the HHS (P = .002) and OHS (P = .002), a higher prevalence of patient-perceived LLD (P = .002), and worse limping (P < .001) than the control group, but the self-administered patient satisfaction scale and VAS pain scores did not differ. However, improvements in the HHS and OHS from preoperative assessment to 3 months were comparable in both groups. At 12 months after THA, there were no significant differences in functional outcomes or self-satisfaction, and the study group showed significantly greater improvements from preoperative assessment to 12 months (P < .05).

CONCLUSION: Patients with severe LLD experienced similar improvement at 3 months after THA as those with mild LLD in terms of the HHS and OHS but showed greater improvement at 12 months postoperatively than patients with mild LLD.