Superior knee flexor strength at 2 years with all‐inside short‐graft anterior cruciate ligament reconstruction vs a conventional hamstring technique

Abstract Purpose To compare the “all‐inside technique” for anterior cruciate ligament (ACL) reconstruction using a short, quadrupled semitendinosus tendon (ST4) autograft and suspensory cortical fixation on both the femoral and tibial side vs the “conventional technique” using a semitendinosus/gracilis (ST/G) autograft fixed with a suspensory device on the femoral side and with an interference screw on the tibial side, in terms of clinical and functional outcomes. Methods A total of 90 patients were enrolled, randomised into two groups, and prospectively followed. Group A comprised 45 patients treated with the all‐inside technique and Group B included 45 patients treated with the conventional ACL technique (55 males, 35 females; mean age 28.7 ± 11.3 years). Patients completed the Lysholm knee score, the International Knee Documentation Committee (IKDC) score, the Knee Injury and Osteoarthritis Score (KOOS), and the Knee Society Score (KSS) preoperatively and at 2 years postoperatively. Anterior tibial translation measurement (KT‐1000 arthrometer) and isokinetic testing of the operative vs non‐operative limb were also conducted and the limb symmetry index (LSI) was determined. Results At 24 months, the Lysholm, IKDC, KOOS, and KSS scores between the two groups were similar (n.s.). Anterior tibial translation between the operative and non‐operative knee was also similar among the two groups (n.s.). Patients of Group A had significantly higher mean LSIs in terms of flexor peak torque (1.0 ± 0.1 vs 0.9 ± 0.1; p < 0.001), time‐to‐peak (0.9 ± 0.1 vs 0.8 ± 0.1; p < 0.001) and total work (0.9 ± 0.1 vs 0.8 ± 0.1; p < 0.001) at 180°/s, and significantly better mean LSI for isometric flexor/extensor ratio at 90° (1.1 ± 0.3 vs 0.8 ± 0.2; p < 0.001). Conclusion The all‐inside ACL reconstruction with an ST4 autograft and cortical button fixation on both ends is a viable alternative to the conventional technique. It affords preservation of knee flexor strength, which is of advantage, especially when treating athletes with ACL injury. Level of evidence I.