Comparative Evaluation of Medial Parapatellar and Transpatellar Tendon Approaches for Intramedullary Interlocking Nailing of Tibial Shaft Fractures: A Prospective Comparative Study.

Introduction  Intramedullary (IM) interlocking nailing is the standard treatment for displaced tibial shaft fractures. Our study aimed to compare postoperative pain, functional recovery, and complication profiles between the medial parapatellar and transpatellar tendon approaches in patients undergoing IM interlocking nailing for tibial shaft fractures. Materials and methods  This prospective comparative study included 60 patients with tibial shaft fractures who underwent IM interlocking nailing; 30 patients each were allocated to the transpatellar tendon group and the medial parapatellar group. The demographic and clinical characteristics were recorded preoperatively. Postoperative outcomes included Visual Analog Scale (VAS) pain scores, knee range of motion (ROM), ankle ROM, operative duration, and postoperative complications. The patients were evaluated on postoperative days 14, 28, and 84. Continuous variables were compared using the independent-samples t-test, categorical variables using the chi-square test or Fisher's exact test, and effect sizes were calculated using Cohen's d. Statistical significance was set at p < 0.05. Results  The mean age was comparable between the transpatellar (41.00 ± 13.82 years) and medial parapatellar (41.11 ± 13.30 years) groups (p = 0.975). Postoperative VAS scores progressively decreased in both groups, without significant differences on day 14 (6.55 ± 1.23 vs. 6.03 ± 1.16; p = 0.097), day 28 (4.10 ± 1.22 vs. 3.57 ± 0.93; p = 0.064), and day 84 (1.81 ± 0.94 vs. 1.43 ± 0.77; p = 0.091). Knee ROM improved significantly in both groups; however, on day 84, the medial parapatellar group demonstrated significantly greater knee ROM than the transpatellar group (118.33 ± 5.30° vs. 111.29 ± 8.06°; p < 0.001; Cohen's d = 1.03). Ankle ROM was comparable throughout follow-up, with no statistically significant differences (day 84: 24.66 ± 1.29° vs. 23.87 ± 3.08°; p = 0.203). Postoperative complications were also comparable between the groups, although anterior knee pain occurred more frequently after the transpatellar approach (26.7% vs. 10.0%). Conclusion  Both surgical approaches achieved satisfactory postoperative outcomes following IM interlocking nailing for tibial shaft fractures. However, the medial parapatellar approach resulted in significantly superior recovery of knee ROM while providing comparable postoperative pain relief, ankle function, operative duration, and complication rates. Therefore, preservation of the patellar tendon may facilitate improved early functional recovery without compromising surgical safety, making the medial parapatellar approach a valuable alternative for the surgical management of tibial shaft fractures.