Sex-Specific Analysis of Quadriceps and Hamstring Strength Following Anterior Cruciate Ligament Reconstruction With...

Background and Objectives: Strength deficits are extremely common following anterior cruciate ligament reconstruction (ACLR). These deficits may be further impacted by concomitant meniscus repair during ACLR. However, there remains limited evidence investigating the effect of meniscus repair on lower-limb strength after ACLR, and particularly if there are between-sex differences in strength after ACLR with and without meniscus repair. Therefore, the purpose of this study was to investigate sex-specific differences in meniscus repair during ACLR on quadriceps and hamstring isometric strength. Methods: Eighty-five (37 females; 19.0 ± 6.6 years old) patient charts were retrospectively evaluated after undergoing ACLR. Variables documented included meniscal status, maximal isometric quadriceps and hamstring strength of the operative (OP) and non-operative (NOP) legs. Three separate 3-way [leg (OP vs. NOP) × sex (males vs. females) × meniscus repair status (yes vs. no)] mixed-factorial analyses of variance (ANOVA) assessed differences in quadriceps and hamstring strength, and the hamstring-to-quadriceps strength ratio (H:Q), at an alpha level of p ≤ 0.05. Results: For H:Q there was a sex by meniscus repair status interaction (p = 0.007). Females who underwent meniscus repair had lower H:Q (18.2%) than those without. Females without meniscus repair had a 20.3% greater H:Q than males without meniscus repair. Males had greater quadriceps strength than females (mean difference ± standard error; 0.58 ± 0.28 N∙kg^-1) and the NOP leg was stronger than OP for quadriceps (0.34 ± 0.08 N∙kg^-1) and hamstring (0.14 ± 0.04 N∙kg^-1) strength across sex. Conclusions: These findings suggest that the H:Q ratio differed according to sex and meniscus repair status. Further, there was a between-limb difference for strength in the quadriceps and hamstrings along with sex-related differences in strength. However, meniscus repair status did not influence raw strength values.