FUNCTIONAL OUTCOMES OF DUAL MOBILITY CUP IN REVISION TOTAL HIP REPLACEMENT (THR) USING HARIS HIP SCORE

Abstract

Background:

Revision total hip replacement (THR) is a surgically demanding procedure associated with higher complication rates compared to primary THR. Dual mobility cup (DMC) implantation can be regarded as a new alternative approach that helps to manage instability in revision procedures. Nevertheless, there is a lack of scientific data concerning South Asian people.

Objective:

To assess the functional outcome of dual mobility cup implantation in revision total hip replacement using the Harris Hip Score (HHS) at three-month follow-up in patients presenting to Ghurki Teaching Hospital, Lahore.

Methodology:

A quasi-experimental prospective cohort study was conducted from December  2025, to April 2026, in the Orthopaedic Department, Ghurki Teaching Hospital, Lahore. A total of 80 patients aged 18–50 years undergoing revision THR with a dual mobility cup were enrolled via non-probability consecutive sampling. Preoperative and postoperative HHS were recorded. A paired t-test was used for pre- and postoperative HHS comparison. A p-value ≤0.05 was considered statistically significant.

Results:

The mean age was 38.6 ± 8.4 years, with 56.2% males and 43.8% females. Mean BMI was 26.8 ± 3.7 kg/m². Aseptic loosening was the most common indication for revision (42.5%), followed by dislocation (28.7%), fracture (17.5%), and infection (11.3%). Mean preoperative HHS was 38.4 ± 9.2, which improved significantly to 78.6 ± 7.8 postoperatively (p <0.001). Postoperative complications were seen in 7 patients (8.75%): dislocation in 2 (2.5%), infection in 2 (2.5%), loosening in 2 (2.5%), and fracture in 1 (1.25%). Post-stratification analysis showed no significant effect of age, gender, BMI, or comorbidities on functional outcome.

Conclusion:

Dual mobility cup implantation in revision THR results in a clinically significant improvement in Harris Hip Score with an acceptable complication profile. These findings support the routine use of DMC in revision hip surgery, particularly in younger patients in our local setting.