Impact of two different intramedullary nail fixations performed through the knee joint on knee osteoarthritis: A retrospective radiological analysis

Although retrograde femoral (RGF) and suprapatellar approach tibial (SPT) nails performed through the knee joint have shown successful outcomes, their effects on knee osteoarthritis remain unclear. This study aimed to evaluate the radiological effects of RGF and SPT nailing on knee osteoarthritis progression. Between January 2014 and February 2024, 35 patients who underwent RGF (Group 1) or SPT (Group 2) nailing met the study criteria. We retrospectively reviewed digital archives and radiological images and recorded demographic data, trauma type, comorbidities, complications, fracture healing time, and follow-up period. In the radiological evaluation, fracture types were classified. Additionally, preoperative and final postoperative anteroposterior radiographs of the knee joint were used to assess the tibiofemoral joint (TFJ), while lateral radiographs were used to evaluate the patellofemoral joint (PFJ). Both joints were categorized according to the Kellgren–Lawrence osteoarthritis (KLOA) grading system. Changes in KLOA grade between the preoperative period and final follow-up were analyzed statistically. The mean age of the patients was 39.0 ± 13.7 years (range: 19–65 years), with 32 (91.4%) male and 3 (8.6%) female patients. RGF nailing (group 1) was performed in 21 patients (60.0%) and SPT nailing (group 2) in 14 patients (40.0%). The median fracture healing time was 5 months in group 1 and 4.5 months in group 2. KLOA grading indicated a statistically significant change in PFJ osteoarthritis in Group 1 (P = .023), but no significant TFJ change (P = .059). Group 2 showed no significant KLOA changes in the PFJ and TFJ (P = .317 and P = .083, respectively). Based on the results of our study, RGF nailing appears to increase the risk of osteoarthritis in the PFJ, whereas SPT nailing does not significantly affect the risk of osteoarthritis in either the PFJ or TFJ. Further comprehensive studies with larger patient cohorts are needed to confirm these findings.