Medial Femoral Trochlea Osteochondral Flap Reconstruction of the Previously Unsalvageable Kienbock-Associated Lunate With a Coronal Split.

ABSTRACT

PURPOSE: Patients with Kienbock disease can present with coronal fracture and collapse of the proximal lunate (Unified B2/Bain grade 1, 2B). Traditionally, this was considered unsalvageable. However, medial femoral trochlea (MFT) osteochondral reconstruction, used to recreate the proximal lunate surface, can be paired with reduction and repair of the coronal plane fracture, thus restoring midcarpal congruity. The purpose of this study was to report radiographic and clinical outcomes following lunate coronal fracture fixation at the time of MFT osteochondral reconstruction. METHODS: This was a retrospective study performed at a single institution. We identified patients with Kienbock disease who underwent MFT osteochondral reconstruction from 2014 to 2023. Patients were included if they had a coronal fracture of the lunate distal articular surface fixed at the time of surgery. Radiographic and clinical parameters were evaluated, including carpal height ratio, union rate, presence of heterotopic ossification, need for revision surgery, and patient-reported outcome measures. RESULTS: Thirty-three patients were included, with a mean age of 27.5 years (range 15-41); 19 (58%) were women. Mean radiographic follow-up time was 5.8 months, and mean clinical follow-up time was 22.6 months. Union was achieved in 30/33 patients (91%). Carpal height ratio improved from 1.32 to 1.4. Two patients (6%) required reoperation, one for removal of heterotopic ossification and another for conversion to proximal row carpectomy. Patients demonstrated meaningful improvement in brief Michigan Hand Questionnaire and Patient-Reported Outcomes Measurement Information Upper Extremity scores. Range of motion before and after surgery was similar. CONCLUSIONS: Lunate coronal fracture fixation with MFT osteochondral reconstruction represents an additional management option in select patients with Kienbock disease. This technique restores the midcarpal joint during lunate reconstruction and may allow patients to avoid salvage procedures. Early radiographic and clinical outcomes are promising. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.