Navicular Fracture

Imaging of Müller-Weiss Disease

Müller-Weiss disease (MWD) is the result of a dysplasia of the tarsal navicular bone. Over the adult years, the dysplastic bone leads to the development of an asymmetric talonavicular arthritis with the talar head shifting laterally and plantarly, thus driving the subtalar joint into varus. From a diagnostic point of view, the condition may be difficult to differentiate from an avascular necrosis or even a stress fracture of the navicular, but fragmentation is the result of a mechanical impairment rather than a biological dysfunction.Standardized weight-bearing radiographs (anteroposterior and lateral views) of both feet are usually enough to diagnose MWD. Other imaging modalities such as multi-detector computed tomography and magnetic resonance imaging in early cases for the differential diagnosis can add additional details on the amount of cartilage affected, bone stock, fragmentation, and associated soft tissue injuries. Failure to identify patients with paradoxical flatfeet varus may lead to an incorrect diagnosis and management. Conservative treatment with the use of rigid insoles is effective in most patients. A calcaneal osteotomy seems to be a satisfactory treatment for patients who fail to respond to conservative measures and a good alternative to the different types of peri-navicular fusions. Weight-bearing radiographs are also useful to identify postoperative changes.

Robot-assisted percutaneous screw fixation in the treatment of navicular fracture

Background

Long recovery time, large scar, postoperative swelling and pain are possible side effects of open reduction internal fixation (ORIF) for tarsal navicular fractures. Early exercise instruction is made possible by the use of an intraoperative robot-assisted percutaneous invasive closed reduction internal fixation. The goal of the trial was to determine whether percutaneous screw internal fixation with robot assistance might be used to treat navicular fractures.

Methods

27 patients with navicular fractures had surgical treatment between June 2019 and December 2021. Of those, 20 instances were treated with ORIF, while 7 cases had robot-assisted percutaneous screw internal fixation. At the final follow-up, the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score and the visual analogue scale (VAS) score were compared to determine outcomes and function.

Results

Follow-up was obtained in all 27 patients after surgery, with a mean follow-up time of 21.81 months, ranging from 15 to 29 months . In the 7 instances of robot-assisted group, percutaneous guide wire insertion and screw placement only needed one attempt and the depth and position of the implant were both satisfactory. In the ORIF group, there were two patients who sustained cutaneous nerve injuries. The AOFAS score and the VAS score of the group receiving robot-assisted navigation percutaneous screw fixation were 92.25 ± 2.22 and 0.75 ± 0.25 respectively at the last follow-up, while 82.25 ± 7.15 and 0.50 ± 0.29 were the respective values for the ORIF group.

Conclusion

Intraoperative robot-assisted percutaneous closed reduction internal fixation for tarsal navicular fractures can accomplish exact localization of fracture site, reduce soft tissue damage and operative time. According to current view, this method offers fewer complications, a faster recovery after surgery, and more patient satisfaction.