Posterolateral antiglide plating of unstable AO-type B lateral malleolar fractures is biomechanically stronger than lateral plating and causes less wound healing problems and less frequent hardware removal. However, the distal end of the plate or the screws may cause peroneal tendinitis. The limits of safe hardware placement have not been established.
A retrospective analysis of 70 patients was done to determine hardware position and identify peroneal tendon lesions. An adjunct study involved dissection of the retromalleolar region in 10 embalmed cadaver specimens to study the anatomy of the osteosynovial peroneal groove.
Thirty of 70 (43%) patients had the plate removed because of discomfort or signs of peroneal tendinitis. Peroneal tendon lesions were identified intraoperatively in nine of the 30 (30%) patients. Only two of these nine patients had felt symptoms preoperatively. Placement of the distal end of the plate distal to the proximal third of the lateral malleolus did not correlate with a peroneal tendon lesion. However, this placement combined with a screw in the most distal hole of the plate and a prominent screw head was strongly correlated with peroneal tendon lesions. In the anatomic specimens the shape of the osteosynovial part of the peroneal groove was uniform, but its length showed greater variation than the length of the foot.
Antiglide plating of lateral malleolar fractures led to high rates of hardware removal and peroneal tendon lesions. Correlations were found to low placement of the plate together with a protruding screw head in the most distal hole of the plate. Distal screw placement should therefore be avoided or the hardware should be removed early. Absence of subjective signs of peroneal tendon irritation does not exclude even a major tendon lesion.