[Effects of modified posteromedial approach combined raft technique for posterior Pilon fractures with collapsed articular surface]

Objective: To evaluate the effects of modified posteromedial approach combined raft technique in the treatment of posterior Pilon fractures with collapsed articular surface. Methods: A retrospective analysis was conducted on the clinical data of 51 patients with posterior Pilon fractures combined with collapsed articular surface treated in West China Hospital between January 2014 and June 2017. There were 30 males and 21 females with an average age of 49 years (range, 19-66 years).Subjective assessment of the results was performed according to the pain visual analog scale (VAS).The general function recovery was assessed with American Orthopaedic Foot & Ankle Society (AOFAS) ankle hindfoot scale at the latest follow-up. The fracture reduction quality was determined according to Burwell-Charnley imaging standard by the anteroposterior(AP)/mortise X-ray view and three-dimensional CT of the ankle on the 3rd day after operation. The t-test was used to compare the normal distribution parameters. Results: Primary healing of incision and bone were obtained in all patients without loosening, breakage or infection of internal fixation in (3.7±0.7) months (range, 3-6 months). According to the Burwell-Charnley's standards, 50 cases achieved anatomical reduction, 1 case achieved fair reduction. According to AOFAS scales, the results were excellent in 41 cases, good in 9, and fair in 1; the excellent rate was 98.0%. According to the AOFAS scores, the average score was 93.6±2.2. The preoperative VAS score was 7.5±1.1, and the postoperative score was 0.3±0.7, in which the difference was statistically significant (t=31.231, P=0.000). At the last follow-up, the angle of injured side were 13.3°±3.4° in dorsal extension, 33.5°±4.7° in plantar flexion, and 46.9°±6.1° in the range, while angel of uninjured side were 19.8°±2.3°, 36.0°±5.7° and 55.6°±2.7°, respectively; there were significant differences in the up-mentioned indexes between the both sides (t=78.932, 121.231, 113.432, all P<0.05). Conclusion: Excellent short-term effectiveness can be achieved through the modified medial approach in patients with posterior Pilon fractures, which can be used to restore the ankle joint surface under direct vision; and with the raft technique, a small plate is used to fix small fragments firmly with less soft tissue complications.