Comparative anatomy of the mouse and human ankle joint using Micro-CT: Utility of a mouse model to study human ankle sprains.

The use of mouse models as a tool to study ankle sprain requires a basic understanding of the similarities and differences between human and mouse ankle joint anatomy. However, few studies have been conducted that address the merits and drawbacks of these differences in the functioning of joints. Twenty hindfoot specimens were obtained from 10 male C57BL/6J mice and scanned using micro-CT. The foot and ankle skeletal structures were reconstructed in three dimensions. Morphological parameters were then measured using a plane projection method and normalized data were compared with those of human ankles. There was no significant difference in the malleolar width, maximal tibial thickness, tibial arc length, trochlea tali arc length or trochlea tali width of the mouse specimens compared with the human model. However, a groove was observed on the talar dome in the mouse specimens which was not observed in humans, the talar dome being more symmetric. The mouse ankle was to a large extent able to mimic the mechanism of a human ankle and so a mouse model could be appropriate for expanding our understanding of ankle biomechanics in general. However, the structural differences in the talar dome in the mouse and human should not be ignored. Although there are some differences in the mouse and human ankle that cannot be ignored, compared to other animals, the human ankle is more similar to that of the mouse.

Comparison of Arthrodesis and Non-fusion to Treat Lisfranc Injuries.

OBJECTIVE: "Lisfranc joint injury" is comprised of a tarsometatarsal joint-complex injury. The Lisfranc complex injury is always a challenge for orthopedists, and the optimum treatment is still up for debate. Anatomic reduction and stable internal fixation prove to have no satisfactory outcomes. This research aims to compare the clinical curative effects, complications and radiographic features of arthrodesis and non-fusion of the Lisfranc joint in the follow-up of the patients who suffered Lisfranc injuries. METHODS: A comparative retrospective study of 25 patients with acute or subacute Lisfranc complex injuries was conducted between September 2013 and March 2015 in the First Affiliated Hospital of Soochow University. All patients were classified by Myerson classification. Eight patients were treated with arthrodesis, while 17 patients received non-fusion operations. The clinical curative effects, complications and image differences were compared between the two groups. American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score, Short Form-36 (SF-36) and Visual Analogue Scale (VAS) score were evaluated for each patient during the follow-up. All statistics were analyzed using the SPSS software system. RESULTS: All fractures healed for both the arthrodesis group and the non-fusion group. Patients in the arthrodesis group had a higher AOFAS score compared with patients in the non-fusion group (94.00 vs. 88.58, P = 0.034). Complications occurred in eight patients (8/17, 47%) in the non-arthrodesis group, including the second and third phalanx abduction (1), talipes cavus (2), eversion deformity of front foot (3), eversion deformity of calcaneus (1), as well as postoperative infection (1). Only two patients (2/8, 25%) in the arthrodesis group suffered complications. One was a limitation of motion of the front foot and pain during walking; the other was an eversion deformity of front foot. CONCLUSION: Primary arthrodesis has advantages compared to primary open reduction and internal fixation (ORIF): reduced foot deformity rates, sustained biomechanical morphology of the feet, reduced complications, higher level of function recovery, shorter time of surgical procedures, fewer complications, higher AOFAS score and fewer frequency of complications. According to our research, primary arthrodesis may be a better choice for treating Lisfranc injury.