Anterolateral skin incision for total knee arthroplasty is associated with lower prevalence of postoperative hypoesthesia at 1-year: a meta-analysis of randomised trials.

BACKGROUND

A meta-analysis of randomised trials was conducted to compare clinical and functional outcomes between the standard anteromedial or midline skin incision and unconventional anterolateral incision for total knee arthroplasty (TKA).

METHODS

This study was registered prospectively on the INPLASY database. Literature search was performed on 14th December 2024 in accordance with PRISMA. Only randomised controlled trials (RCTs) comparing anterolateral incision (ALI) versus standard (midline or anteromedial) incision (SI) were included and quality-assessed. Outcomes at 1 year postoperatively were prevalence of numbness, surface area of skin numbness, degrees of knee flexion, Visual Analogue Scale (VAS), Forgotten Joint Score (FJS) and Knee Injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

Eight RCTs totalling 609 patients (ALI 276 vs. SI 333) were included. Mean age, BMI and proportion of male patients were comparable between the two groups. There was no baseline difference between the two groups for the incision length or operative duration. Statistical difference was observed for two outcomes favouring the ALI group: prevalence of hypoesthesia (OR 0.36, CI 0.17-0.77, P = 0.008) and surface area of numbness (SMD -1.04, CI -1.80 to -0.28, P = 0.007). No significant difference was observed in KOOS (SMD 0.16, CI - 0.07 to revman 0.38, P = 0.17), FJS (SMD -0.14, CI -0.39 to 0.12, P = 0.30) and VAS (SMD -0.10, CI -0.39 to 0.20, P = 0.51).

CONCLUSION

An anterolateral incision to TKA results in a lower rate and smaller surface area of numbness at 1-year, with no difference in patient-reported outcome measures.