Anterior Cruciate Ligament Reconstruction With Unilateral 8-Strand Hamstring Tendon Autograft Demonstrated Promising Clinical, Radiological, and Second-Look Arthroscopic Outcomes at 2-Year Minimum Follow-up.

Background: The diameter of 4-strand semitendinosus and gracilis (ST/G) autograft varies between 6 and 8 mm in most Asian patients. Recent studies showed higher failure rates for ST/G anterior cruciate ligament (ACL) reconstructions (ACLRs) performed with graft diameters <8 mm. The 8-strand ST/G ACL graft preparation technique has been reported to achieve diameters of up to 9.5 to 11.5 mm.

Hypotheses: (1) The diameter of the ACL graft would be >8 mm in all cases (100%) by using the 8-strand graft preparation technique and (2) the ACLR with 8-strand ST/G autograft would show satisfactory functional scores, excellent knee stability with good graft signal, and promising graft healing status.

Study Design: Case series; Level of evidence, 4.

Methods: From January 2020 to January 2022, 67 consecutive patients who underwent primary ACLR with unilateral 8-strand ST/G autograft were prospectively enrolled. Clinical outcomes were assessed using functional scores (Lysholm, Tegner, and International Knee Documentation Committee [IKDC] objective grade) and physical examination results (pivot-shift test and manual maximum KT-1000 side-to-side difference [SSD]). Radiologically, intra-articular ACL graft signal intensity (grade 1, good; grade 2, moderate; grade 3, poor) and anterior subluxation of the lateral compartment (ASLC) and medial compartment (ASMC) in extension relative to the femoral condyles were evaluated on magnetic resonance imaging (MRI) scans. Additionally, second-look arthroscopic evaluations were used to assess the synovial coverage (A, normal [>75%]; B, nearly normal [50%-75%]; C, abnormal [25%-50%]; and D, severely abnormal [<25%]) of the ACL graft.

Results: Ultimately, 50 patients were enrolled and completed the minimum 2-year follow-up tasks. The mean graft diameter for the 8-strand graft configuration was 9.3 mm (range, 8.5-10.5 mm). At final follow-up, all of the following showed significant improvements (pre- vs postoperatively): mean Lysholm score (52.7 vs 93.2; < .001), median Tegner Activity Scale (5 vs 8; < .001), IKDC objective grading results (27 grade C and 23 grade D vs 48 grade A and 2 grade B; < 0.05), pivot-shift tests (27 grade 1+ and 23 grade 2+ vs 48 grade 0 and 2 grade 1; < .001) and manual maximal KT-1000 SSD (6.7 vs 1.0 mm; < .001). Additionally, 46 (92%) patients showed grade 1, 3 (6%) showed grade 2, and only 1 (2%) showed grade 3 graft intensity on MRI scans. The synovial coverage of the grafted tendon was observed as grade A in 46 (92%) and grade B in 4 (8%) patients during the second-look arthroscopic exploration. However, there were no significant differences observed in the mean ASLC and ASMC in extension, respectively, before (5.9 vs 4.1 mm; = .10) and after (4.8 mm vs 3.5 mm; = .34) surgery.

Conclusion: The 8-strand graft configuration technique proposed in this study ensured that the diameter of the ST/G ACL autograft reached ≥8 mm. Additionally, this technique demonstrated promising clinical scores, knee stability, and graft maturity in ACLR patients at 2-year minimum follow-up in this cohort.