A Randomized Controlled Trial: Functional and Radiological Outcome in Closed Tibia Shaft Fracture Managed with Suprapatellar Interlocking Nail versus Infrapatellar Interlocking Nail

BACKGROUND: Intramedullary nailing is the standard treatment for closed tibial shaft fractures, but controversy persists regarding the best approach: suprapatellar (SPILN) versus infrapatellar (IPILN) interlocking nailing. This randomized controlled trial (RCT) compares the functional and radiological outcomes of these two techniques. MATERIALS AND METHODS: Forty patients with closed tibial shaft fractures (AO/OTA 42A-B) were randomly allocated to SPILN (n = 20) or IPILN (n = 20). Functional outcome was assessed using the Lysholm knee score, and radiological outcome was assessed using the Radiographic Union Scale for Tibial fractures (RUST) at 3, 6, 9, and 12 months. Operative time, fluoroscopy time, intraoperative blood loss, and alignment were also assessed. Continuous variables were analyzed with an unpaired t-test and categorical variables with a Chi-square test, with P < 0.05 considered significant. RESULTS: Baseline demographics were comparable between groups. SPILN had significantly shorter operative time (63.2 ± 4.9 vs. 78.2 ± 3.7 min; P < 0.001), lower fluoroscopy time (137.8 ± 9.1 vs. 168.2 ± 8.8 s; P < 0.001), and reduced blood loss (104 ± 25.7 vs. 137.8 ± 9.2 ml; P < 0.001). Lysholm scores were consistently higher in SPILN at all followup points (94.7 ± 2.3 vs. 88.8 ± 1.6 at 12 months; P < 0.001). RUST scores showed no significant difference at any time point, with similar union by 12 months (11.6 ± 0.5 vs. 11.7 ± 0.5). Sagittalplane alignment was significantly better in SPILN (0.95 ± 0.73 vs. 1.56 ± 0.70 degrees; P = 0.01), whereas coronal alignment was equivalent. CONCLUSION: SPILN offers superior intraoperative efficiency and functional outcomes compared with iIPILN, without compromising radiological healing, and may be preferred for closed tibial shaft fractures in highvolume trauma centres.