Modified posteromedial approach via lateral side of flexor hallucis longus for the treatment of posterior Pilon fracture

Objective: To compare the clinical efficacy and the level of muscle and soft tissue damage between modified posteromedial approach via lateral side of flexor hallucis longus and modified posteromedial approach in the treatment of posterior Pilon fracture. Methods: Total of 43 patients (27 males and 16 females, aged from 19 to 71 years) diagnosed with posterior Pilon fracture from June 2016 to June 2018 in Foshan Hospital of Traditional Chinese Medicine were randomly divided into observation group (modified posteromedial approach via lateral side of flexor hallucis longus, 21 cases) and control group (modified posteromedial approach, 22 cases) according to the operation approach. The preoperative waiting time, intraoperative time, intraoperative blood loss, hospitalization time and the complications were recorded and compared between the two groups. The differences of blood creatine kinase (CK), myoglobin (Myo) and C-reactive protein (CRP) at different time points before and after operation were compared between the two groups to elevate the level of muscle and soft tissue damage. The fracture reduction qualities of the two groups were compared by Burwell-Charnley criteria. The differences of fracture healing time, range of motion of metatarsophalangeal joint of the great toe (MTP-ROM), ankle range of motion (Ankle-ROM), American Orthopaedic Foot & Ankle Society (AOFAS) score and visual analogue scale (VAS) score of pain were compared between the two groups at the last follow-up. Results: The observation group and the control group were followed-up for (19±6) months and (16±8) months, respectively; there was no significant difference between the two groups (P>0.05). There were no significant differences in preoperative waiting time, intraoperative blood loss, hospitalization time and fracture healing time between the two groups (all P>0.05). At the last follow-up, there was no significant difference in the MTP-ROM and Ankle-ROM between the two groups (both P>0.05); the AOFAS score of the observation group was 88.2±7.8 and it was 84.5±7.6 in the control group (P>0.05); the VAS score of the observation group was (0.9±1.0) and it was (1.3±0.8) in the control group(P>0.05). Anatomical reduction rate in observation group was higher than that in control group (90.5% vs 81.8%, P>0.05). The operation time in the observation group was (87±16) min and it was (98±11) min in the control group (P 0.05). There was no nerve injury in the observation group, while 2 cases (9.0%) of nerve paralysis occurred in the control group. No incision infection and checkrein deformity of the Hallux was found in the two groups. Conclusion: The modified posteromedial approach via lateral side of flexor hallucis longus can obtain good operative field exposure, and does not increase muscle and soft tissue injury, with shorter operative time and fewer complications, without nerve injury and checkrein deformity, it is a safe approach for the treatment of posterior Pilon fracture.