[Reconstruction of anterior talofibular ligament and calcaneofibular ligament with autologous peroneus brevis tendon in the treatment of chronic lateral ankle instability].

OBJECTIVE: To explore the clinical efficacy of reconstruction the anterior talofibular ligament and calcaneofibular ligament with autologous peroneus brevis tendon for the treatment of chronic lateral ankle instability. METHODS: The clinical data of 42 patients with chronic lateral ankle instability treated by anatomical reconstruction of anterior talofibular ligament and calcaneofibular ligament with autologous peroneus brevis tendon from July 2016 to July 2019 was retrospectively analyzed. Including 30 males and 12 females, age ranged from 25 to 46 years old with an average of (37.6±12.4) years. There were 15 cases of left foot and 27 cases of right foot, the time from injury to operation was 3 to 12 months with a mean of (7.4±2.8) months. And 14 patients had tenderness in lateral collateral ligament area, 28 patients complained of multiple ankle sprains while walking on the flat ground. At 12 months after operation, the talar tilt angle and visual analogue scale(VAS)were observed, ankle joint varus stress and anterior drawer test were performed to check the mechanical stability of the ankle joint, American Orhopaedic Foot and Ankle Society(AOFAS) was used to score the ankle and hindfoot functions and evaluate the curative effect. RESULTS: Forty patients were followed up for 12 to 48 months with an average of (28.3±10.0) months, 2 cases were lost. The VAS decreased from(4.50±0.93) scores before surgery to (1.10±0.30) scores at 12 months after surgery;the talar tilt angle was reduced from (12.26±1.13)° before operation to (4.60±0.45)° at 12 months after operation;the AOFAS score increased from (65.10±7.50)scores before surgery to (84.40±3.95) scores at 12 months after surgery;all the differences were statically significant(P<0.05). According to the AOFAS score, 27 cases got excellent results, 7 good, 5 fair, and 1 poor. One patient had the symptoms of sural nerve injury after operation, and the symptoms were relieved after oral Mecobalamin for 3 months. The remaining patients had no complications such as nerve injury, infection, and skin necrosis. There was no instability of ankle joint, and both ankle varus stress test and drawer test were negative. CONCLUSION: Autologous peroneal brevis tendon with double bone channel pass through the tendon (modified Chrisman-Snook operation) can anatomically reconstruct the anterior talofibular ligament and the calcaneofibular ligament, restore the stability of the patient's ankle joint, reduce postoperative complications, and restore ankle joint function well.

Double-layered lateral meniscus.

A case of double-layered lateral meniscus in which an accessory proximal hemimeniscus was overlying the body and posterior horn of the lateral meniscus is here reported. The accessory hemimeniscus lays marginal and parallel to the normal lateral meniscus with its periphery dissociated from the capsule and was significantly thinner and more mobile than its underlying counterpart. It was resected arthroscopically, and the patient's symptoms were significantly improved. This case demonstrates an interesting and extremely rare anatomical abnormality of the lateral meniscus.

[Effects of slope gradient on slope runoff and sediment yield under different single rainfall conditions].

Based on the field observation data of runoff and sediment yield produced by single rainfall events in runoff plots, this paper analyzed the variation patterns of runoff and sediment yield on the slopes with different gradients under different single rainfall conditions. The differences in the rainfall conditions had little effects on the variation patterns of slope runoff with the gradient. Under the conditions of six different rainfall events in the study area, the variation patterns of slope runoff with the gradient were basically the same, i. e., the runoff increased with increasing gradient, but the increment of the runoff decreased slightly with increasing gradient, which was mainly determined by the infiltration flux of atmospheric precipitation. Rainfall condition played an important role on the slope sediment yield. Generally, there existed a critical slope gradient for slope erosion, but the critical gradient was not a fixed value, which varied with rainfall condition. The critical slope gradient for slope erosion increased with increasing slope gradient. When the critical slope gradient was greater, the variation of slope sediment yield with slope gradient always became larger.

[Fabrication of larynx-shape tissue engineered cartilage by means of filling together with wrapping with pedicle myofascial flap].

OBJECTIVE: To explore the method of fabricating larynx-shape tissue engineered cartilage by means of filling together with wrapping with pedicle myofascial flap. METHODS: Serial steps of solution casting, extrusion molding and particulate leaching were used to make larynx-shape [poly (3-hydroxybutyrate-co-3-hydroxyhexanoate), PHBHH] biomaterial models. The chondrocytes were seeded onto PHBHH models to form cell-PHBHH composites for culture in vitro for one week and then to fill and wrap larynx-shape composites with pedicle myofascial flap. After that to implant larynx-shape composites in situ on the back of adult New Zealand white rabbits (experimental groups n = 9). Control groups (n = 3) were the same measure as experimental groups but without chondrocytes on PHBHH models. Finally, morphological observation, HE & special staining and immunohistochemical test were conducted to evaluate the cartilage regeneration and its shape at 6, 8 and 12 weeks following implantation. RESULTS: The PHBHH models appeared to be hollow half-trumpet with edges and corners of larynx-shape and its porosity > 90%. Pedicle myofascial flap using fascia as lining presented rich blood supply and had enough to fill and wrap larynx-shape composites. Tissue engineered larynx-shape cartilage specimens could be harvested at different period. It was demonstrated that the cartilaginous tissue formed in 6 weeks after implantation through histological and immunohistochemical examination and further maturity in 12 weeks and 18 weeks. But no cartilaginous tissue showed without chondrocytes on PHBHH as control groups to implant at the same time. CONCLUSION: It seems that pedicled myofascial flap showed sufficient blood supply and that the filling together with wrapping method with pedicled myofascial flap is appropriate for fabricating larynx-shape tissue engineered cartilage.