One-stage bilateral total hip arthroplasty versus unilateral total hip arthroplasty: A retrospective case-matched study

Abstract

Background: One-stage bilateral hip replacement has the advantage of involving a single anesthesia, single hospital admission and single rehabilitation program. The theoretic drawback is increased surgical risk. Few French series have been reported, and none with comparison versus unilateral arthroplasty. We therefore conducted a comparative case-control study between 1-stage bilateral (1B-THA) and unilateral total hip arthroplasty (U-THA), assessing (1) morbidity/mortality, (2) survival, and (3) functional scores and forgotten hip rates.

Hypothesis: In a selected ASA 1 or 2 population, 1B-THA shows complications rates and implant survival comparable to U-THA.

Material and method: Between 2004 and 2018, 327 patients were included: 109 with 1B-THA, 218 with U-THA. One 1B-THA patient was matched to 2 U-THA patients on age, gender, diagnosis, ASA score 1 or 2, and anterior or posterior approach. Minimum follow-up was 12 months. Complications were collected for all patients in both groups. Early (≤90 days) or late (>90 days) morbidity/mortality and implant survival were recorded for both groups. Secondary endpoints concerned blood-sparing strategy and blood loss, functional scores, and patient satisfaction.

Results: Mortality was zero in both groups. There was no significant difference in complications rates (1B-THA 38.5%, U-THA 40.8%) (p=0.69), whether early (8.3% [9/109] and 7.8% [17/218] respectively [p=0.89]) or late (30.3% [33/109] and 33.0% [72/218] respectively [p=0.61]). Limb-length discrepancy was significantly less frequent in 1B-THA (5.5% [6/109] versus 13.3% [29/218] [p=0.03]). Forgotten hip rate was significantly more frequent in 1B-THA (86% [94/109] versus 70% [152/218] [p=0.01]). Five-year Kaplan-Meier implant survival was 97.2% (95% CI [91.9-99.1]) in 1B-THA and 96.6% (95% CI [93.0-98.4]) in U-THA (p=0.08).

Discussion: One-stage bilateral total hip arthroplasty gave acceptable results in disabling bilateral osteoarthritis of the hip with low surgical risk in selected patients (ASA 1 or 2). Mortality, complications and implant survival were unaffected, but the 1-stage bilateral procedure allowed better control of limb-length and provided a higher rate of forgotten hip.

Level of evidence: III, matched case-control study.

Keywords: 1-stage procedure; Bilateral total hip arthroplasty; Complications; Hip osteoarthritis; Outcome; Postoperative morbidity; Unilateral.