No common peroneal nerve palsies found after a peroneal nerve release prior to TKA in fixed valgus deformities (a retrospective cohort study)

© 2022, The Author(s) under exclusive licence to European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).Purpose: The main purpose of this study was to analyse the incidence of Common Peroneal Nerve Palsy (CPNP) after Total Knee Arthroplasty (TKA) for all alignments. Secondarily, the efficiency and safety of a Peroneal Nerve Release (PNR) prior to TKA in preoperative severe fixed valgus deformities were evaluated to prevent a CPNP. Methods: Overall, 7612 TKAs were performed in the institution from 2009 to 2021. 1913 TKAs were performed by three surgeons, who consistently performed a PNR in case of a fixed valgus deformity of (1) more than 15°, or (2) more than 10° but in combination with a flexion contracture of more than 15°. Patients with fixed valgus deformities of more than 10° were identified (81 knees) and a comparison was made between the patients who received a PNR (26 knees) and those who did not receive a PNR (55 knees). Data for the analysis were collected from patient medical files and were compared with the Chi2-test or Fisher Exact test. Results: A CPNP incidence of 0.2% (16/7612) was found after TKA for all alignments together. No CPNP cases (0%) were developed in the PNR-group, compared to five (9%) in the non-PNR group (p = NS). A larger preoperative valgus angle (17° vs 13°, p < 0.001) and flexion contracture (10° vs 3°, p < 0.001) was present in the PNR group compared with the non-PNR group. No PNR-related complications were reported. Conclusion: The CPNP incidence in this study is consistent with the previous literature. Furthermore, although not significant, the group that received a PNR procedure developed fewer CPNPs compared to the group without PNR. Level of evidence: Retrospective cohort study, III.