Functional scores and prosthetic implant placement are different for navigated medial UKA left in varus alignment.

PURPOSE: The purpose of this study was to analyze the clinical outcomes and radiologic position of the knee in two groups of patients after medial unicompartmental knee arthroplasty (UKA): one group with residual varus axis (RVA) alignment and other one with neutral mechanical axis (NMA) of the lower limb. METHODS: All patients who underwent UKA between January 2015 and January 2018 were evaluated retrospectively. Inclusion criteria were: medial UKA for isolated medial femoro-tibial osteoarthritis, a varus deformity of < 15°, and a minimal follow-up of 2 years. All patients had a preoperative and postoperative clinical examination with functional scores (New International Knee Score (NewIKS) and Knee injury and Osteoarthritis Outcome Score (KOOS) and radiographs. Preoperative and postoperative values for continuous outcomes were compared using the Student's t test for paired data and differences between the groups were compared with the Mann-Whitney U test. p < 0.05 was considered statistically significant. RESULTS: The RVA group consisted of 48 cases of medial UKA in 48 patients (22 females). Mean postoperative hip-knee-ankle (HKA) angle was 174.3° ± 2.8 and the corresponding mean AKI angle (tibial mechanical angle) was 82.9° ± 2.9. The NMA group consisted of 35 cases of medial UKA in 35 patients (14 females). Mean postoperative HKA angle was 178.9° ± 3 and the corresponding mean AKI angle was 85.5° ± 3.1. A significant difference was found between the two groups for the KOOS score and for global NewIKS, with a better score in the RVA group. CONCLUSIONS: RVA alignment after medial UKA results in a significant improvement in functional knee scores at 2-year post-surgery. Return to sport and recreational activities was better than in patients with postoperative NMA. LEVEL OF EVIDENCE: Level 3; retrospective cohort study.

Tibial tunnel expansion does not correlate with four-strand graft maturation after ACL reconstruction using adjustable cortical suspensory fixation.

PURPOSE: Anterior cruciate ligament reconstruction (ACLR) using a short, quadrupled semitendinosus (ST-4) autograft, fixed  with an adjustable suspensory fixation (ASF), has several potential advantages. However, the construct is suspected to generate micromotion, tunnel widening and poor graft maturation. The aim of this study was to evaluate post-operative tibial tunnel expansion, graft maturation and clinical outcomes for this type of ACLR. METHODS: One-hundred and forty-nine patients were reviewed at a minimum of 2 years following 4-ST ACLR, mean 25.6 ± 3.5 months [24-55], with clinical follow-up and MRI scans. Graft maturity of the intra-articular part of the graft and the tibial tunnel portion was assessed using Signal-to-Noise Quotient (SNQ) and Howell score. Tibial tunnel expansion, bone-graft contact and graft volume in the tibial tunnel were calculated from the MRI scans. RESULTS: Mean tibial tunnel expansion was 13 ± 16.5% [12-122]. Mean SNQ for graft within the tibial tunnel was 3.8 ± 7.1 [ - 7.7 to 39] and 2.0 ± 3.5 [ - 14 to 17] for the intra-articular portion of the graft. The Howell score for graft within the tibial tunnel was 41% Grade I, 37% Grade 2, 20% Grade 3, 2% grade 4, and for the intra-articular part 61% Grade 1, 26% Grade 2, 13% Grade 3 and 1% Grade 4. The mean tibial tunnel bone-graft contact was 81 ± 23% [0-100] and mean graft volume was 80 ± 22% [0-100]. No correlation was found between tibial tunnel expansion and graft maturity assessed at both locations. Graft maturity was correlated with higher graft-bone contact and graft volume in the tibial tunnel (p < 0.05). CONCLUSIONS: ST-4 ACLR with ASF had low levels of tunnel enlargement at 2 years. No correlation was found between graft maturation and tibial tunnel expansion. Graft maturity was correlated with graft-bone contact and graft volume in the tibial tunnel. LEVEL OF EVIDENCE: Level III.

Combined ACL and ALL reconstruction reduces the rate of reoperation for graft failure or secondary meniscal lesions in young athletes.

PURPOSE: Graft failure and secondary meniscal tears are major concerns after anterior cruciate ligament (ACL) reconstruction in young athletes. The aim was to evaluate the link between ACL reconstruction with and without anterolateral ligament (ALL) reconstruction and outcomes in young patients participating in pivoting sports. METHODS: This was a retrospective study of data collected prospectively. Patients less than 20 years, involved in pivoting sports and undergoing primary ACL reconstruction with a quadruple hamstring tendon (4HT) graft or 4HT graft combined with anterolateral ligament reconstruction (4HT + ALL) were included. Survival analysis was performed to identify the prognostic indicators for reoperation due to graft failure or secondary meniscal lesions. Knee laxity was assessed and patient reported outcome measures (PROMs) were collected. RESULTS: A total of 203 patients (mean (± SD) age: 16.3 ± 2 years) with a mean follow-up of 4.8 ± 0.9 (range: 3.3‒6.8) years were included. There were 101 4HT and 102 4HT + ALL grafts. Graft rupture rates were 11.9% for 4HT grafts and 5.8% for 4HT + ALL grafts (n.s.). There were 9.9% secondary meniscal procedures for 4HT grafts vs. 1.9% for 4HT + ALL grafts (p = 0.02). With reoperation for graft failure or secondary meniscal lesions at final follow-up as the endpoint, survival was better in the 4HT + ALL group (91.4% vs. 77.8%, respectively; p = 0.03). Absence of ALL reconstruction (HR = 4.9 [95%CI: 1.4-17.9]; p = 0.01) and preoperative side-to-side laxity > 3 mm (HR = 3.1 [95%CI: 1.03-9.1]; p = 0.04) were independently associated with an increased rate of reoperations. Mean (± SD) side-to-side laxity was 1.3 ± 1.3 mm (range: - 2 to 5) for 4HT grafts vs. 0.9 ± 1.3 mm (range: - 6 to 4.8) for 4HT + ALL grafts (n.s.) 6 months post-surgery. The rate of return to the same sport at the same level was 42.2% for 4HT grafts vs. 52% for 4HT + ALL grafts (n.s.). There was no significant difference in subjective outcomes including PROMs between the two groups. CONCLUSION: Combined ALL + ACL reconstruction reduced the rate of graft failure and secondary meniscal injury in young athletes when compared to ACL reconstruction alone. Subjective results were comparable, with a similar rate of complications. Combined reconstruction should be preferred in this young population. LEVEL OF EVIDENCE: Level IV.