Functional outcomes and complication rates of the SPAIRE approach compared to the direct lateral approach in hemiarthroplasty for displaced femoral neck fractures.

Aims: A soft-tissue sparing posterior surgical approach (SPAIRE) for hip hemiarthroplasty after femoral neck fractures is hypothesized to provide better functional results than the standard direct lateral approach, while maintaining a low dislocation rate. The aim of this study was to compare rate of complications and functional results between these approaches in a clinical cohort.

Methods: Prospectively collected registry data on all femoral neck fracture cases treated with hemiarthroplasty between September 2018 and November 2022 in a single Norwegian hospital were analyzed grouped by SPAIRE versus direct lateral approach. Outcomes were prosthesis dislocation, surgical site infection, 30-day mortality, and tests of function three months postoperatively. Linear regression was used for continuous outcomes, and dichotomous outcomes were analyzed by logistic regression and contingency tables.

Results: Of 858 cases, 430 were operated using SPAIRE, and 428 using direct lateral approach. There were no group differences in prosthesis dislocation rate (SPAIRE 0.7 % vs direct lateral 0.9 %, p = 0.725), and no differences in surgical site infections or 30-day mortality. In the patients with three months follow-up (total n = 372; SPAIRE n = 192; direct lateral n = 180) the SPAIRE group had better functional outcomes; New Mobility Score: 6.1 vs 5.0 (difference 1.1, p < 0.001), New Mobility Score change from preoperative: -1.3 vs -1.8 (difference 0.5, p = 0.024), Short Physical Performance Battery: 7.3 vs. 5.9 (difference 1.4, p < 0.001), Walking speed: 0.8 vs 0.7 m/s (difference 0.1, p < 0.001).

Conclusion: We found no differences in the rate of prosthesis dislocations, infections, or mortality between the SPAIRE and the direct lateral approach. Functional outcomes were better in patients operated with the SPAIRE approach.