Peroneal Tendon Lesions Caused by Antiglide Plates Used for Fixation of Lateral Malleolar Fractures: The Effect of Plate and Screw Position

Background: 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. Method: 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. Results: 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. Conclusions: 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.

Recovery of distal hole axis in intramedullary nail trajectory planning

In intramedullary nail (IMN) surgical operations, one of the main efforts for surgeons is to find the axes of two distal holes. Two distal holes on an IMN, which are inside the intramedullary canal of a patient's femur, can only be seen in a lateral X-ray view. For the standard surgical procedure, the localization of the distal hole axes is a trial-and-error process which results in a long surgical time and large dose of X-ray exposure. In this paper, an algorithm to derive the three-dimensional position and orientation of the distal hole axis was developed. The algorithm first derives the nail axis through two X-ray images. Then the distal hole axis is calculated through projecting back the hole boundary on the X-ray image from a lateral view to three-dimensional space. A least-squares method is used to determine the centres of the front hole and the back hole through iteration. The algorithm has been tested with real data and it was robust.