Do lateral extra-articular tenodeses play a role in the control of sagittal knee laxity in short hamstring tendon graft ACL reconstruction? A retrospective study of 80 cases with and without tenodesis.

INTRODUCTION: Lateral extra-articular tenodesis (LET) associated with an intra-articular anterior cruciate ligament reconstruction (ACLR) provides better rotational control, especially in knees with injuries to the anterolateral structures that are characterized by the presence of a gross pivot shift. However, the role of LET in the control of sagittal knee laxity remains debated. We hypothesized that LET plays a role in the control of sagittal knee laxity. PATIENTS AND METHODS: This was a retrospective, single-center, single-surgeon study of 80 patients operated on between January 2014 and December 2016 for a complete primary ACL tear. We compared 43 patients who underwent an isolated short hamstring tendon graft ACLR with 37 patients who underwent an ACLR using intra- and extra-articular grafts. Knee laxity measurements were taken with a GNRB® arthrometer preoperatively, at 1, 3, 6, and 9months (M1-M9), 1year, and at the last follow-up. The side-to-side differences (healthy vs. operated knees) in graft laxity (ΔL in mm) and compliance (ΔC in µm/N) were calculated for each patient from the generated force-displacement curves. RESULTS: No differences were found between the 2 groups in terms of the ΔL and ΔC evolvement profiles. All laxity parameters decreased significantly between the preoperative assessment and M1. ΔL and ΔC increased at low forces between M1 and M9. ΔL and ΔC stabilized after M9. DISCUSSION: Sagittal control remains the primary function of the ACL. The anterolateral ligament (ALL) reconstruction and LET do not improve sagittal postoperative laxity. CONCLUSION: Sagittal laxity measurements recorded during the postoperative period did not show that adding LET to short hamstring tendon graft ACLRs improved either graft laxity or compliance. LEVEL OF EVIDENCE: IV, retrospective study.

Joint laxity and graft compliance increase during the first year following ACL reconstruction with short hamstring tendon grafts.

PURPOSE: Evaluating joint laxity and graft compliance after ACL surgery may be used to quantify biomechanical graft properties during the ligamentization process. This study aimed to analyse the evolvement of joint laxity and graft compliance of short hamstring tendon grafts after ACL reconstruction (ACLR). METHODS: Forty-seven patients that underwent ACLR were retrospectively enrolled. Joint laxity was quantified with a GNRB® arthrometer before surgery, then at 15 days, at 1/3/6/9 months (M1-M9), at 1 year postoperatively and then again at the last mean follow-up (FU) of 14.7 ± 3.0 months. The side-to-side laxity difference (ΔL in mm) was measured at 30 and 60 N at every FU, additionally at 90 N from M3 on and at 134 N from M6 on. The side-to-side compliance difference (ΔC in µm/N) was calculated for each graft. RESULTS: Mean ΔL and ΔC decreased significantly between preoperative and M1 for all applied forces (at 30 N, ΔL: 0.8 mm, p < 0.0001; ΔC: 25.9 µm/N, p < 0.001). Between M1 and M9, ΔL increased significantly at 30 N (p = 0.02) and 60 N (p < 0.001), while ΔC increased by 15.2 µm/N at 30 N (p = 0.003) and 14.9 µm/N at 60 N (p = 0.001). Between M9 and the last FU, there were no significant differences for ΔL and ΔC. CONCLUSION: Joint laxity and graft compliance evolve during the first postoperative year with a phase between the first and ninth postoperative month of relative weakness. According to the established evolvement profile, return to pivoting or contact sports should be considered only after stabilization of joint laxity and graft compliance. LEVEL OF EVIDENCE: Retrospective cohort study, Level III.

Treatment of large deep osteochondritis lesions of the knee by autologous matrix-induced chondrogenesis (AMIC): Preliminary results in 13 patients.

BACKGROUND: Osteochondral defects due to advanced osteochondritis of the knee eventually cause osteoarthritis. Autologous matrix-induced chondrogenesis (AMIC) may hold potential for overcoming the treatment challenges raised by defects larger than 2cm2. The primary objective of this study was to assess medium-term functional outcomes of AMIC. The secondary objective was to confirm the absence of adverse events. HYPOTHESIS: AMIC significantly improves knee function in patients with osteochondritis responsible for osteochondral defects grade III or IV in the International Cartilage Repair Society (ICRS) classification. MATERIAL AND METHODS: A total of 13 consecutive patients managed using AMIC between September 2011 and November 2016 were included in a prospective, single-centre, single-surgeon study. There were 8 males and 5 females with a mean age of 29 years (range, 15-51 years). Among them, 9 had had previous surgery. The ICRS grade was IV in 12 patients and III in 1 patient. The defects had a mean surface area of 3.7cm2 (range, 2.2-6.9cm2) and mean depth of 0.5mm (range, 0.4-0.8). In each patient, knee function was assessed by an independent examiner based on validated instruments (Knee injury and Osteoarthritis Outcome Score [KOOS], subjective International Knee Documentation Committee [IKDC] score, and visual analogue scale [VAS] pain score). RESULTS: After a median follow-up of 24 months (range, 12-42 months; minimum, 1 year), 11 patients had significant improvements, with mean increases in the IKDC score and KOOS of 27 and 28 points, respectively. The scores remained stable after the first year. Of the 2 patients with poorer outcomes, 1 had a history of multiple surgical procedures and the other was a 51-year-old female with a defect surface area of 6.9cm2. No post-operative complications were recorded. CONCLUSION: AMIC is a reliable single-stage method that is both reproducible and widely available. AMIC significantly improves knee function scores in patients with large osteochondral defects due to advanced osteochondritis of the knee. LEVEL OF EVIDENCE: IV, prospective cohort study.