Superficial Peroneal Nerve Incarceration in the Fibular Fracture Site of a Pronation External Rotation Type Ankle Fracture

Comparison of Two Surgical Approaches to Supination-External Rotation-Type Ankle Fractures

Objective

To compare the clinical outcome and postoperative complications of the treatment of supination-external rotation-type ankle fractures using the posterolateral approach in the prone position and the lateral approach in the supine position.

Methods

A retrospective cohort study was conducted in our hospital, including a total of 66 patients ranging from January 2013 to February 2016, regardless of age or sex. All the patients were classified as Lauge-Hansen supination-external rotation (SER)-type ankle fractures and were assigned to receive an open reduction and internal fixation (ORIF) through a posterolateral approach performed in the prone position (the "posterolateral approach group," 32 patients), or a lateral approach performed in the supine position (the "Lateral Approach Group," 34 patients). In the posterolateral approach group, 5 patients had Grade II fractures, 8 had Grade III fractures, and 19 had Grade IV fractures; among whom, 12 underwent fixation of the posterior malleolus with hollow screws and 6 with plates, and none of them had fixation of the distal tibiofibular syndesmosis; in the lateral approach group, 4 patients had Grade II fractures, 12 had Grade III fractures, and 18 had Grade IV fractures; among whom, 21 received fixation of the posterior malleolus, and 5 received fixation of the distal tibiofibular syndesmosis. The postoperative complications and ankle scores were recorded.

Results

After 1 year of follow-up, in the posterolateral approach group, the incision healed by primary intention and sutures were removed 2 weeks after the operation in all patients; 1 patient had pain in the region posterior to the fibula, presumably peroneal tendon irritation induced by internal fixation, which disappeared after fracture union and fixation device removal; no loosening or breakage of the internal fixation device was reported; the rate of good to excellent results was 96.8% at 12 months. In the lateral approach group: 1 case of wound infection, 1 case of necrosis of lateral skin flap, and 3 cases of lateral skin irritation were reported; the rate of good to excellent results was 94.6% at 12 months.

Conclusion

Compared with the traditional lateral approach, the posterolateral approach for the reduction and internal fixation of supination-external rotation-type ankle fractures performed in the prone position has more satisfactory clinical outcomes, with better reduction, more secure fixation, and smaller wound.

CT can stratify patients as low risk for tibial neuropathy following a talus fracture

OBJECTIVE

Determine the incidence of tibial neuropathy following talus fractures and CT's ability to stratify patients at risk for developing post-traumatic neuropathy.

MATERIALS AND METHODS

In this IRB-approved retrospective analysis, 71 talus fractures and 8 contralateral control ankle CTs were reviewed by one observer blinded to clinical information. CT evidence suggestive of tibial neurovascular bundle injury included nerve displacement, perineural fat effacement/edema, and bone touching nerve. The association between these CT findings and clinically evident tibial neuropathy was analyzed. A semi-quantitative likelihood score was assigned based on the degree of the CT findings around the nerve. Interobserver agreement was calculated between 2 other readers.

RESULTS

Twenty-five percent of patients in this cohort had clinical evidence of tibial neuropathy. There was a high specificity (0.87-0.93) and negative predictive value (0.83-0.87), a moderate accuracy (0.80-0.82), but a lower sensitivity (0.33-0.56) associated with the CT findings. Among the CT findings, nerve displacement (p < 0.0001) and bone touching nerve (p = 0.01) were associated with tibial neuropathy. A likelihood score of 2-5 was associated (p = 0.007-0.015) with tibial neuropathy. The presence of tibial neuropathy and nerve recovery were not associated with hospital length of stay, while CT findings were. There was substantial agreement between the three readers: likelihood scores 2+ (k = 0.78) and 3+ (k = 0.72).

CONCLUSIONS

Tibial neuropathy occurs following talus fractures, and CT findings may help surgeons narrow down the number of patients requiring close neurological follow-up.