AAOS Now

Published 3/25/2022
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Brandon May

Posterior Malleolus Repair of Unstable Rotational Ankle Fractures Leads to High Healing Rate

A study to be presented Friday found that direct repair of the posterior malleolus in the prone position in patients with unstable rotational ankle fractures was associated with a high rate of healing and no incidences of readmissions or deep infections. The use of posterior malleolus fixation may reduce or eliminate the need for trans-syndesmotic stabilization in these patients. The findings of the study will be presented by medical student Connor Littlefield.

Seventy-seven consecutive patients with unstable ankle fractures involving the posterior malleolus were identified retrospectively from a fracture database. Over an eight-year period, all patients underwent ORIF (open reduction–internal fixation) with direct repair of the posterior malleolus. Surgical fixations were performed by a single fellowship-trained orthopaedic trauma surgeon.

In the operations, the fibular and posterior malleolar fragments were reduced anatomically and fixed using small and mini-fragment plates and screws.

Approximately 37.7 percent of patients were flipped supine, with the medial malleolus repaired via a separate medial approach. Out of 55 repaired medial malleoli, 29 were fixed in the prone position.

After operation, patients underwent a standardized rehabilitation regimen with six weeks’ worth of non–weight-bearing exercise with ankle range of motion (ROM) and lower-extremity strengthening. Patients ultimately advanced to weight bearing as tolerated and started physical therapy to improve the injured ankle’s strength and ROM.

Researchers recorded 60 trimalleolar fractures (77.9 percent), 13 bimalleolar (lateral and posterior malleolus) fractures (16.9 percent), and four Maisonneuve fractures (posterior malleolus alone, 5.2 percent). Nearly 60 percent (n = 46) of patients experienced an ankle fracture dislocation.

Most patients (98.7 percent) did not need a syndesmotic screw. Additionally, syndesmotic screw was not required in 97.8 percent of fracture dislocations. The mean width of the posterior malleolus fragment was 8.2 ± 3.8 mm (range = 2.1–19.9 mm), whereas the percentage of the articular surface on the lateral radiograph was 24.0 percent.

All patients experienced a healed ankle fracture by a mean of 2.9 ± 1.1 months after surgery. Mean ankle ROM was 20 ± 10 degrees for dorsiflexion, 33 ± 10 degrees for plantarflexion, 7 ± 5 degrees for inversion, and 7 ± 4 degrees for eversion. All but one patient (n = 76) had an anatomic mortise reduction. About 11 percent (n = 9) had a noninfectious wound complication. Four patients (5.2 percent) had dysesthesia in the sural nerve distribution, whereas one patient (1.3 percent) had minor loss of the medial malleolus reduction.

The study will be presented as Paper 567 on Friday at 8:20 a.m. in Room S106a.

Mr. Littlefield’s coauthors of “Unstable Rotational Ankle Fractures Treated with Anatomic Mortise Repair and Direct Posterior Malleolus Fixations” are Jack Drake, BS, and Kenneth Egol, MD, FAAOS.

Brandon May is a freelance writer for AAOS Now.