Unicondylar intra-articular tibial plateau osteotomies provide favourable outcomes and avoid arthroplasty in posttraumatic deformities at 4-year mean follow-up.

Purpose: This study aimed to evaluate the functional and radiological outcomes, complications and procedure survival in patients with posttraumatic tibial plateau deformities treated with unicondylar intra-articular tibial plateau osteotomy (UIATPO), comparing medial and lateral approaches.

Methods: A retrospective study was conducted on all patients with posttraumatic intra-articular tibial plateau deformities who underwent surgical correction at a single centre between 2016 and 2022, with a minimum follow-up of 24 months. Patient characteristics, radiological correction, patient-reported outcome measures (PROMs), including the Lysholm and knee injury and osteoarthritis outcome score (KOOS), and complications were recorded. The primary outcome was functional assessment using the KOOS and Lysholm scales. Secondary outcomes included complications categorised into early (≤30 days), intermediate (31-90 days) and late (>90 days) postoperative periods, surgical reinterventions, and radiographic correction of alignment.

Results: Twenty-six patients were included (46.15% male), with a mean age of 44.7 years and a mean follow-up of 48.7 months (range: 25-95). Lateral UIATPO was performed in 81% (n = 21) of cases. Statistically significant correction of the hip-knee-ankle (HKA) angle and posterior tibial slope was achieved in the lateral osteotomy group when comparing pre- and postoperative measurements, while no significant changes were observed in patellar height. Clinical outcomes were favourable, with high KOOS and Lysholm scores and no significant differences between lateral and medial groups. The main complication was infection, which occurred predominantly in medial osteotomies and was initially managed successfully with debridement, antibiotics and implant retention. No patient required conversion to knee arthroplasty at final follow-up.

Conclusions: UIATPOs demonstrated good functional and radiological outcomes, with low rates of major complications and no need for conversion to knee arthroplasty at intermediate-term follow-up, supporting its role as a joint-preserving option in selected cases.

Level of evidence: Level III, retrospective cohort study.