Background: Peroneal tendon lesions can cause debilitating pain, but operative treatment remains controversial. Some studies recommend peroneal tenodesis or transfer if more than half of the tendon is affected. However, clinical outcomes and inversion/eversion motion after peroneal transfer have not been investigated yet.
Methods: Patients who underwent distal peroneus longus to brevis transfer for major peroneus brevis tendon tears with a minimum follow-up of 2 years were included. Clinical outcome parameters included the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, the German Foot Function Index (FFI-D), and Karlsson-Peterson score. Functional outcome was tested with a standardized active range-of-motion (ROM) and isokinetic strength measurement protocol, including concentric and eccentric eversion and inversion tests.
Results: Of total 23 eligible patients, 14 (61%) were available for follow-up. Clinical outcome scores were good with AOFAS 86 ± 16 points, FFI-D pain 26% and FFI-D disability 26%, and Karlsson-Peterson score 78 ± 23 points. There was no difference in strength in comparison to the contralateral foot (all P > .05). Isokinetic strength was 16.3 ± 4.9 Nm (108% of contralateral side) and 18.8 ± 4.5 Nm (101%) at concentric 30 deg/s and eccentric 30 deg/s eversion tests, as well as 15.7 ± 5.2 Nm (102%) and 18.7 ± 3.3 Nm (103%) at concentric 30 deg/s and eccentric 30 deg/s inversion tests, respectively. There was no difference in ROM compared to the contralateral side (eversion/inversion 14.5-0-18.7 vs 14.1-0-16.1 degrees).
Conclusion: Peroneus longus to brevis transfer is a viable option for treating severe peroneus brevis tendon tears and does not compromise measurable strength or ROM in inversion or eversion in comparison to the contralateral ankle joint.
Level of evidence: Level IV, prospective case series.
Keywords: isokinetic measurement; longus to brevis; peroneal tendon lesion; peroneal transfer.