Introduction

There has recently been an increasing emphasis on gender-specific differences in outcomes after anterior cruciate ligament reconstruction (ACLR), with evidence to suggest a higher overall risk of ipsilateral knee injury and a lower return to sports in females after ACLR. The use of a quadriceps tendon (QT) autograft has gained popularity in recent years, and it has been termed the graft of the future. However, there is limited evidence of its outcomes specifically in female patients. Given this background, the aim of this systematic review was to assess the outcomes of ACLR with a QT autograft specifically in female patients and elucidate any gender-specific outcome differences.

Methods

This systematic review was conducted in accordance with PRISMA guidelines. Four online databases were used for review of literature (Medline, EMBASE, Cochrane and Google Scholar). The search terms used were ‘anterior cruciate ligament reconstruction’ OR ‘ACL reconstruction’ OR ‘anterior cruciate ligament’ AND ‘quadriceps’ OR ‘quadriceps tendon graft’ OR ‘QT graft’ with filters for human subjects and females. After selecting studies for full-text analysis, those using QT autograft for ACLR but not reporting female-specific outcomes were excluded. The MINORS (Methodological Index for Non-Randomised Studies) tool was used to critically appraise included studies. For statistical analysis, forest plots were generated where available data allowed for comparison of outcomes with males.

Results

Eight studies were included in this review, of which seven were comparative cohort studies and one included data from a randomized control trial. A total of 702 female knees underwent QT ACLR with a mean age of 22.9 years (14 – 58 years). The pooled re-tear rate from five studies involving 361 females at a mean follow-up of 62.7 months (24 – 139 months) was 7.4% (0% - 9.9%), whereas in males (n = 317) this was 8.8% (0% -12.6%) (p = 0.5). Functional outcomes at 2-year follow-up in females from three studies showed a mean pooled IKDC score of 89.5 (89.3 – 91.6), Tegner Activity Scale 6.09 (5.7 – 8.02) and Lysholm score 85.4 (82.0 – 92.9), with no outcome showing statistical difference when compared to males. At 24 months, the mean extension loss in females was 0.07 degrees (-0.22 degrees – 0.58 degrees). At 6 months post-operatively, females were found to have a significantly lower quadriceps strength limb symmetry index (p < 0.001), but with no significant difference in side-to-side instrumented laxity (p = 0.44), when compared to males. The return to sport rate ranged from 71.4% - 82.7% with the ACL-RSI score ranging from 66.1 – 69.5.

Conclusion

Our review of available literature shows a paucity of data reporting regarding female-specific outcomes of ACLR with QT graft. However, evidence from current literature suggests good functional outcome scores, similar retear rates as males and no significant loss of extension when using the QT graft in female patients. ACLR with QT graft is a suitable alternative option in females.