Importance of Space-Occupying Anatomical Variations in Peroneal Tendoscopy

Background: We hypothesized that peroneal tendons disorders are more commonly associated with anatomical variations, which could overcrowd the retrofibular groove. Methods: This single-center retrospective case study covered 84 consecutive cases that had undergone peroneal tendoscopy. Peroneal tendoscopy was performed on 82 patients, predominantly female (3:1) with a median age of 46 years. The preoperative evaluation and all the procedures were performed by a single surgeon using a standardized technique. Results: Two patients required revision surgery 8 and 52 months after the index procedure due to persistent posterolateral ankle pain. Peroneal tendoscopy was performed as a solitary procedure in 45.1% (37/82) of cases, while the remaining cases involved peroneal tendoscopy as a supplementary procedure. Low-lying peroneus brevis muscle belly (LLMB) was the most common finding in this series in 53.7% (44/82) of cases. In 41.5% (34/82) of cases, longitudinal tears of the peroneus brevis tendon were noted. Some patients presented with more than 1 concomitant peroneal tendon pathology. The LLMB was observed in 23.5% (8/34) of cases with a longitudinal tear of the peroneus brevis tendon. Conclusion: Peroneal tendon anatomical variations, especially LLMB, were associated with the presence of peroneus brevis tendon ruptures and intrasheath peroneal tendon subluxations as well as posttraumatic posterolateral ankle pain. Due to high rates of undiagnosed and misdiagnosed cases of LLMB preoperatively, we believe special care should be taken to recognize it during tendoscopy. Peroneal tendoscopy is a high-efficiency, low-complication method to treat some peroneal tendon conditions. Level of Evidence: Level IV, case series.