Minimally Invasive Percutaneous Plate Osteosynthesis (MIPPO) Versus Intramedullary Interlocking Nailing (IMILN) in Extra-articular Proximal Third Tibial Fractures: A Prospective Comparative Study.

Background and objective Extra-articular fractures of the proximal third of the tibia are technically demanding injuries due to the complex deforming muscular forces and frequently compromised soft tissue envelope. The optimal treatment strategy for this fracture subtype remains unsettled, particularly regarding the choice between minimally invasive percutaneous plate osteosynthesis (MIPPO) and intramedullary interlocking nailing (IMILN). This study was undertaken to compare these two treatment modalities and determine their relative effectiveness. Methods A single-center, prospective, comparative study employing alternating allocation was conducted at IMS and SUM Hospital, Bhubaneswar, with patient recruitment carried out from September 2024 to February 2025, and final clinical and functional follow-up at 12 months completed by March 2026. Fifty-two adults aged 20-60 years with AO/OTA 41A2 fractures, including Gustilo-Anderson grade I and II open injuries, were sequentially allocated to either MIPPO (n = 26) or IMILN (n = 26). The primary outcomes included time to radiological union and 12-month functional assessment using the Knee Society Score (KSS), Lower Extremity Functional Scale (LEFS), and Johner and Wruhs grading scale. Continuous variables were compared using the independent-samples t-test, while categorical variables were analyzed using the chi-square or Fisher's exact test as appropriate. Statistical analyses were performed using IBM SPSS Statistics version 21.0 (IBM Corp., Armonk, NY). Results Forty-six patients completed the one-year follow-up (MIPPO, n = 24; IMILN, n = 22). Mean radiological union time was 16.1 weeks (MIPPO) versus 16.9 weeks (IMILN) (mean difference: -0.8 weeks, 95% CI: -4.0 to 2.4; p = 0.62). Final union rates were 23/24 (95.8%) and 21/22 (95.5%), respectively. Malreduction > 5° occurred in 4/26 (15.4%, MIPPO) and 5/26 (19.2%, IMILN) (p = 0.71). Mean KSS was 80.2 versus 80.8 (mean difference: -0.6, 95% CI: -7.0 to 5.8; p = 0.85), and mean LEFS was 65.2 versus 67.3 (mean difference: -2.1, 95% CI: -6.6 to 2.4; p = 0.35). Excellent or good Johner and Wruhs grades were achieved in 18/24 (75.0%, MIPPO) and 18/22 (81.8%, IMILN). Partial weight-bearing was initiated earlier in the IMILN group (two to three postoperative days vs. three to four weeks; p < 0.001). Intraoperative adjuncts were required in 13/26 (50.0%) of IMILN versus 3/26 (11.5%) of MIPPO procedures (p = 0.005). Conclusions Within the limitations of this small, single-center cohort study, MIPPO and IMILN demonstrated comparable union rates and one-year functional outcomes for AO/OTA 41A2 fractures. IMILN facilitated earlier mobilization but necessitated adjunct procedures more frequently and was associated with anterior knee pain. MIPPO was associated with minimal knee-related morbidity, albeit with a more gradual rehabilitation timeline. Implant selection should therefore be guided by fracture morphology, soft-tissue condition, and locally available instrumentation rather than an absolute preference for either construct.