Popliteal Artery Entrapment Syndrome: A Rare Cause of Interwoven Nitinol Stent Fracture After Femoropopliteal Interventions.

Stent fractures have been described after femoropopliteal interventions with relevant clinical sequelae, including restenosis and reocclusion. We report 2 cases of fractures of a novel interwoven nitinol stent with high radial strength and fracture resistance as a result of entrapment syndrome of the popliteal artery. (Level of Difficulty: Advanced.).

Avulsion fracture of the medial head of the gastrocnemius muscle associated with multiple ligament injuries before closure of the growth plate: a case report.

BACKGROUND: Avulsion fracture of the medial head of the gastrocnemius muscle is a very rare phenomenon. There are no reports of avulsion fractures associated with multiple ligament injuries before closure of the growth plate. The authors present a case of avulsion fracture of the insertion of the medial head of the gastrocnemius muscle associated with posterior cruciate ligament injury and an avulsion fracture of the medial collateral ligament at the femoral attachment. CASE PRESENTATION: A 15-year-old Japanese boy was injured by contact with another player while playing soccer. He was immediately admitted to the authors' hospital with knee pain. Radiography and computed tomography revealed an avulsion fracture of the medial collateral ligament at the femoral attachment and an avulsion fracture of the medial head of the gastrocnemius muscle. In examination under anesthesia, the Lachman test was negative and posterior drawer test was positive. Fixation of the avulsion fractures of the medial collateral ligament and medial head of the gastrocnemius was performed 9 days after the injury. After fixation, valgus instability at full extension had disappeared. The knee was immobilized in a brace for 2 weeks postoperatively. One year postoperatively, the posterior drawer test was slightly positive; however, our patient was able to ambulate without pain and returned to sports without feeling instability in his knee. CONCLUSION: A rare case of avulsion fracture of the gastrocnemius muscle combined with multiple ligament injuries before closure of the growth plate is described. A satisfactory result was obtained by fixation of the avulsed bone fragments of the gastrocnemius muscle and medial collateral ligament. The authors believe that avulsion fracture of the medial head of the gastrocnemius muscle associated with posterior cruciate ligament injury should be repaired.

Tibial plateau posterior column fractures treated via the posteromedial approach dissecting the gastrocnemius medial head / 中华创伤骨科杂志

Objective To discuss the treatment of tibial plateau posterior column fractures via the posteromedial approach which dissects the medial head of the gastrocnemius muscle.Methods From July 2013 to September 2016,7 patients were treated at Department of Orthopaedics and Trauma,The First Affiliated Hospital to Dalian Medical University by surgery via the posteromedial approach dissecting the medial head of the gastrocnemius muscle for tibial plateau posterior column fractures.They were 6 men and one woman,aged from 38 to 61 years (49.3 years on average).According to AO/OTA classification,4 cases belonged to type 41-B3.3,one to type 41-B3.1,one to type 41-C3.3 and one to type 41-C3.1.According to the three-column classification,3 cases were categorized into three-column fracture,2 cases into fracture of both medial and posterior columns,and 2 cases into simple posterior column fracture.Of the posterior column fractures,5 had the medial posterior column split and the lateral column collapsed,and 2 had the medial posterior column split.According to Schatzker classification,5 cases were categorized into type Ⅳ,one into type Ⅴ and one into type Ⅵ.Fracture reduction was assessed according to the Rasmussen criteria postoperation.The knee function was assessed at final follow-ups using The Hospital for Special Surgery (HSS) scoring system.The postoperative complications were documented.Results Insertion rupture of the posterior cruciate ligament was found in one case,lateral meniscus injury in 2 cases,and tibial external dislocation combined with bone fragment incarceration into the lateral femoral condyle in one case.All the lesions were repaired.All the incisions were healed at the first stage.No major neurovascular injuries were found.The 7 patients were followed up for 8 to 12 months (mean,11.4 months).Bony union was achieved in all after 12 to 16 weeks (mean,14.3 weeks).The postoperative Rasmussen reduction scores averaged 17.7 points.The average tibial plateau tilt angle was 9.5°postoperatively and 10.8° at final follow-ups;the average tibial plateau varus angle was 86.7° postoperatively and 87.3° at final follow-ups.The HSS knee scores at final follow-ups averaged 91.4 points.No significant reduction loss,implants loosening,infection or malunion was observed at final follow-ups.Conclusion The posterior medial approach which dissects the medial head of the gastrocnemius muscle is a safe and practical one for treatment of tibial plateau posterior column fractures,because it can well expose the posterior column of the entire tibial plateau so that is beneficial to the anatomical reduction of the fracture and placement of implants,leading to fine short-term curative effect.

Interaction between gastrocnemius muscle weakness and moderate exercise deteriorates joint integrity in rat knee.

The aim of this study was to determine the effect on the knee joint of the interaction between ankle muscle weakness and moderate exercise. Gastrocnemius muscle weakness was induced by intramuscular injection of botulinum toxin type A (BTX) in rats. Low-speed treadmill running (12 m/min for 60 min) was applied for 6 weeks in rats with and without BTX. Untreated animals were used as controls. After BTX injection, the gastrocnemius muscle weakness was confirmed by 3-D motion analysis in kinematic features of the hindlimb during locomotion as an increased maximal dorsiflexion angle during the stance phase. Serum biomarker analysis by enzyme-linked immunosorbent assay revealed that low-speed running decreased the catabolic effect on type II collagen. However, the inhibition of catabolism induced by running exercise was significantly counteracted by BTX injection. In addition, thinning of the cartilage layer and a reduction in the chondrocyte density was also found in the tibial plateau of the knee in the BTX-injected rats after running for 6 weeks. These data suggest that moderate exercise have a positive effect on joint homeostasis. However, ankle muscle weakness may alter the mechanical environment of the knee and impair the integrity of joint cartilage with moderate exercise.

Surgical treatment for popliteal artery entrapment syndrome.

OBJECTIVE: To evaluate the long-term outcomes of surgical treatment for popliteal artery entrapment syndrome (PAES). MATERIALS AND METHODS: This study was undertaken from a retrospective review of case notes of patients treated for PAES between August 1974 and July 2013. We examined patients' characteristics and surgical procedures, and evaluated long-term outcomes including clinical symptoms and graft or native artery patency. RESULTS: Twenty-nine limbs (24 patients, mean age: 32 years) underwent surgery. Popliteal arteries were occluded (n = 18) stenosed (n = 7) and normal (n = 4). Twenty-five limbs required both revasularization (interposition [n = 24] and bypass surgery [n = 1]) and myotomy. Four limbs were treated solely with myotomy. During the long-term follow-up period, three limbs required reoperation. The overall primary graft and native popliteal artery patency rates at one and 5 years were 96.3% and 91.9%, respectively. CONCLUSION: The treatment of PAES with myotomy and selective revascularization achieves good short- and long-term outcomes. The use of an interposition vein graft reconstruction is associated with minimal morbidity and good long-term patency.

Long-term morphologic changes in skeletal muscles of SD rats after botulinum toxin A gel injection / 第三军医大学学报

0.05).Histopathologic examination showed no changes in the right gastrocnemius muscles injected with BTXA gel,but ultrastructurally the myopathic changes were clearly visible,like diffuse sarcomere disruption and saroplasmic reticulum expanding.The myofibre degeneration showed no remission 12 months after BTXA gel injection.Conclusion BTXA is dissolved in gel evenly.The long-lasting myofibre degeneration in BTXA gel paralyzed muscles may reflect that the paralyzed muscles fail to regain their unique function and recovery of muscle contraction.

THE FORMATION OF THE pOPLITEAL VEIN / 解剖学报

Popliteal fossa dissections were performed on two hundred adult extremities and the patterns of the deep venous system were observed. Three general types were established for the popliteal vein and its branches. Single large trunk representing the popliteal vein at the level of the knee joint occurs only in 32.00％, two venous trunks at this level in 65.50％ and three venous trunks in 2.50％. Furthermore, considerable variations of the formation of popliteal veins were found. The patterns of popliteal vein were divided into three main types and eleven subtypes. Type Ⅱa occurs most frequently (41.50％). The size of each vein of the deep venous system was measured. The average calibre of the single popliteal vein is 6.89mm (ranging between 4.0-11.5 mm). The veins from the gastrocnemius muscle join the single or the two popliteal trunks respectively. The veins of the soleus muscle drain into the peroneal and posterior tibial veins. The short saphenous vein typically terminates in the popliteal vein. Variations in its termination were described.