Is quadruple semitendinosus tendon strands autograft a better choice than hamstring autograft for anterior cruciate ligament reconstruction? A comparative study with a mean follow-up of 3 years.

PURPOSE: The purpose of this study was to compare the clinical outcomes of ST4 with those of STGs with a minimum follow-up of 3 years. The hypothesis was that functional outcomes of the ST4 technique are at least as good as those of the STG technique. STUDY DESIGN: Cohort study. Level of evidence, 3 METHODS: Eighty-seven consecutive patients underwent isolated ACL reconstruction, 50 with the ST4 and 37 with STG. At the femoral side for both groups, the system of the fixation of the graft used a cortical fixation support and at the tibial side the group STG used an interference screw and the ST4 group used a tape locked system fixed by an interference screw. Clinical results were compared: IKDC score, KT-1000 arthrometry, radiologic evaluation of the differential laxity, as well as the Tegner score and the KOOS score. RESULTS: Two patients had a rerupture (STG), one in the ST4 group. The analysis of the subjective clinical results showed no statistically significant difference between the 2 groups. Differential laximetry was 0.7 mm ± 0.4 (0 to 2 mm) for the ST4 group and 1.6 ± 0.5 mm (0 to 3 mm) for the STG group with a statistically significant difference in favor of the ST4 group (p < 0.05). Age, sex, and presence of meniscal lesions were the factors influencing the KOOS score. CONCLUSION: This study comparing the clinical and laximetric results at the minimum 3-year follow-up of 2 ACL reconstruction techniques (ST4 vs STG) confirms the working hypothesis with an overall better score for the ST4 group.

A comparison of four tibial-fixation systems in hamstring-graft anterior ligament reconstruction.

The aim of this study was to evaluate at time-zero four tibial fixations on four major criteria: the elongation and cyclic stiffness of the hamstring graft construct under cyclic loading, the yield load and pullout stiffness under load at failure. Four fixation systems were tested: the Delta screw, the WasherLoc, the TightRope Reverse and the tape locking screw on 32 tibiae of adult pigs using 32 pairs of human semitendinosus and gracilis tendons. Two tests were performed: cyclic tests using loads at 70-220 N, to measure the elongation at the end of the cycles, followed by load-to-failure testing to measure the yield load and the cyclic stiffness. The mean elongation was 1.23 mm for the TLS, 3.81 mm for the Delta, 3.59 mm for the WasherLoc and 3.91 mm for the TightRope. The mean yield loads and SD were 1,015 ± 129 N for the TLS, 844 ± 394 N for the Delta, 511 ± 95 N for the WasherLoc and 567 ± 112 N for the TightRope. The results showed the significant superiority of TLS and Delta over WasherLoc and tibial TightRope in regard to yield load. The results showed the significant superiority of TLS over the other fixations in regard to slippage. The TLS system and the Delta screw provide a better quality of primary fixation to the tibia, but further in vitro studies are needed.

Does retrograde tibial tunnel drilling decrease subchondral bone lesions during ACL reconstruction? A prospective trial comparing retrograde to antegrade technique.

BACKGROUND: The main goal of this study was to assess iatrogenic subchondral bone lesions following three different anterior cruciate ligament (ACL) reconstruction techniques and their association with early postoperative pain. METHODS: A multicenter prospective comparative study was conducted in 2012. Each center performed a specific ligamentoplasty technique: two used retrograde and the other antegrade tibial tunnel drilling. Peri- and postoperative analgesia and systematic early postoperative magnetic resonance imaging (MRI) protocols were standardized. The main assessment criterion was tibial subchondral lesions (microfractures or bone oedema) on MRI during the first postoperative week. Secondary criteria were the assessment of postoperative pain for two days using a Visual Analogical Scale (VAS 0-10) and consumption of analgesics. RESULTS: Forty-three patients were included in three centers, 15 in the "antegrade group" and 28 in the "retrograde group", mean age is 32.5±9.1years, 14 women/29 men. All included patients underwent postoperative MRI. There were no subchondral tibial microfractures, but oedema was significantly more frequent in the antegrade group (p=0.0001). Tibial subchondral oedema was correlated to greater early postoperative pain (p=0.01). Multivariate analysis identified tibial tunnel diameter as an independent factor of early postoperative pain. The smaller the tibial tunnel diameter, the greater the mean early postoperative pain (≤8mm (18 patients) 3.4±1.5 vs. >8mm (25 patients) 1.8±1.7, p=0.004) and the more frequent the presence of edemas (10/18 vs. 2/25, p=0.001). CONCLUSION: The present clinical study confirmed the benefit of retrograde tibial tunnel drilling for tibial subchondral bone lesions and showed a correlation between these lesions and early postoperative pain. LEVEL OF EVIDENCE: II; therapeutic study - prospective cohort study.