Postoperative clinical outcomes of unicompartmental knee arthroplasty in patients with isolated medial compartmental osteoarthritis following medial meniscus posterior root tear.

BACKGROUND: Cartilage degradation progresses rapidly following medial meniscus posterior root tear (MMPRT). Unicompartmental knee arthroplasty (UKA) has been performed for medial compartmental osteoarthritis following MMPRT. We evaluated the clinical and radiographic outcomes of UKA for medial compartmental osteoarthritis after an untreated MMPRT. METHODS: Twenty-one patients who underwent UKA for isolated medial compartment osteoarthritis following MMPRT were retrospectively investigated. Clinical outcomes were assessed using the Knee Injury and Osteoarthritis Outcome Score and knee range of motion. The posterior tibial slope and tibial component inclination were evaluated using plain radiographs. RESULTS: The mean follow-up periods were 25.5 ± 13.8 months. Clinical outcomes improved significantly postoperatively. The mean postoperative knee extension angle was -1.1° ± 2.1°, and the knee flexion angle was 134.3° ± 4.9°. The posterior tibial slope angle decreased from 9.0° ± 2.0° preoperatively to 5.4° ± 1.8° postoperatively, and postoperative tibial component inclination at the final follow-up was 2.9° ± 1.1° varus. No aseptic loosening or deep infections were observed. CONCLUSION: UKA significantly improved clinical outcomes and could be a viable surgical option for treating isolated medial compartmental osteoarthritis accompanied by untreated MMPRT.

Tibial Tunnel Positioning Using the Posterolateral (PL) Divergence Guide in Anterior Cruciate Ligament Reconstruction.

The aim of this study was to evaluate tunnel coalition and inter-tunnel distance by comparing the tibial tunnel position in double-bundle anterior cruciate ligament (ACL) reconstruction performed with a conventional guide versus a posterolateral (PL) divergence (PLD) guide. Subjects were 43 patients (ACL tip aimer: 20 knees; PLD guide: 23 knees) who underwent double-bundle ACL reconstruction between September 2014 and December 2017. In all cases, the tibial tunnel position, tunnel edge distance and tunnel angles were evaluated based on CT images. Clinical outcome was evaluated using the Lachman test, pivot-shift test, and Lysholm score. Tibial tunnel positions were similar between the conventional and PLD guide groups, while tibial tunnel edge distance was significantly less in the conventional group. Tunnel coalition was observed in 5 knees in the conventional and no knees in the PLD guide group. Distance between two tibial tunnel centers was 9.1 mm for the tip aimer, and 10.5 mm for the PLD guide. Creation of the PL tunnel tended to involve insertion from a more medial aspect for the PLD guide group than the conventional guide group. No differences in clinical outcomes were noted. The PLD guide can be used to create anatomically-positioned PL tunnels, and reduce the probability of occurrence of tunnel coalition.

Combining pullout suture and retrograde screw fixation for anterior cruciate ligament tibial eminence avulsion fractures: A case report.

This report describes a novel arthroscopic technique for the treatment of anterior cruciate ligament (ACL) tibial eminence avulsion fractures. A 16-year-old boy who was diagnosed with a left ACL tibial eminence avulsion fracture was treated by arthroscopic fixation. Two bone tunnels were created from the anterior tibial cortex into the fracture bed, and a strong suture passed through the ACL just above its insertion was pulled out through them for reduction and fixation. A retrograde cannulated screw fixation was added for stronger fixation. Weight-bearing and range of motion exercises were started immediately after surgery. Radiographically, bone union was obtained 6 months postoperatively. During second-look arthroscopy (24 months postoperatively), there was no loss of reduction and no subsequent meniscal or cartilage injuries. At that point, the Lysholm score was 95, and the International Knee Documentation Committee score was 96.

Features of human autologous hamstring graft elongation after pre-tensioning in anterior cruciate ligament reconstruction.

PURPOSE: Precise pre-tensioning protocol of the graft has not been determined in anterior cruciate ligament (ACL) reconstruction. The aims of this study are to measure the human autologous graft elongation, and to reveal what portion of the graft elongated greater after pre-tensioning in ACL reconstruction. METHODS: Twenty-four hamstring tendon grafts which were harvested from patients were included. A continuous load of 150 N was applied to the graft twice for 30 seconds each (150 N-1 minute), and the same loading was repeatedly applied (150 N-2 minute). The amount of elongation of the tendon portion (Length T) and the stitched portion (Length S) were measured after each pre-tensioning. RESULTS: Length S gradually increased by 1.57 ± 0.67 mm after the 150 N-1 minute pre-tensioning and by 2.12 ± 0.76 mm after the 150 N-2 minute pre-tensioning, respectively. Length T was not significantly elongated after 150 N-1 min (p = 0.66) and 150 N-2 min (p = 0.59). CONCLUSIONS: Graft elongation of the approximately 2 mm was observed, particularly in the stitched portion. It is necessary for a surgeon to focus on careful removal of slack from each stitch during suturing.