ObjectiveTo evaluate the biomechanical characteristics and effectiveness of repairing anteroinferior tibiofibular ligament and fixing the posterior malleolar fracture in reconstructing syndesmotic stability after ankle fracture of pronation-external rotation type (PER) stage IV. MethodsTwenty-four normal lower extremity cadaver specimens were collected and made into intact ankle specimens. A MTS Bionix 858 test system was used to measure the maximum rotation of the foot under a static axial load of 150 N, internal rotation torque to the tibia at a rate of 1°/second and 4 N·m torque. Then a fracture of PER stage IV model was established in each specimen. Internal fixation of lower tibiofibular ligament union was performed by screws in group A, fixation of posterior malleolar fractures in group B, fixing posterior malleolar fracture combined with repairing anteroinferior tibiofibular ligament in group C (8 specimens each group). Then the maximum rotation of the foot was measured under the same condition, and the syndesmotic stability was calculated. Between July 2009 and September 2012, 32 patients with ankle fracture of PER stage IV were treated. There were 19 males and 13 females with an average age of 35 years (range, 20-63 years). The locations were the left ankle in 14 cases and the right ankle in 18 cases. The time from injury to admission was 3.5 hours on average (range, 1-72 hours). Open reduction and plate compression internal fixation were performed in fibula, and medial malleolus was fixed by conpression screws, then anteroinferior tibiofibular ligament was mended and posterior malleolar fracture was fixed by screws. ResultsThe preservation rates of syndesmotic stability after repair were 46.2%±12.3%, 62.6%±10.7%,and 66.5%±12.6% in groups A, B,and C, respectively; groups B and C were significantly superior to group A (P<0.05),but no significant difference was found between groups B and C (P>0.05). All patients achieved wound healing by first intention, and were followed up 12-24 months (mean,15 months). All fractures healed,with an average healing time of 11.2 weeks (range, 10-14 weeks) on the X-ray films. No seperation of inferior tibiofibular syndesmosis was observed during the follow-up period. American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score was 88.4 on average (range, 61-98) at last follow-up; the results were excellent in 13 cases,good in 15 cases, and fair in 4 cases, with an excellent and good rate of 87.5%. ConclusionIn patients with ankle fracture of PER stage IV, a combination of fixing the posterior malleolar fracture and repairing anteroinferior tibiofibular ligament can reconstruct syndesmotic stability effectively.
Objective To compare the effectiveness between the posterolateral approach and the posterolateral combined posteromedial approaches in the treatment of Mason type 2B posterior malleolar fracture. Methods A retrospective analysis was performed on the clinical data of 79 patients with posterior ankle fracture who met the selection criteria between January 2015 and January 2022. There were 62 cases of Mason 2B Pilon subtype and 17 cases of avulsion subtype. Among Mason 2B Pilon subtype patients, 35 were treated with posterolateral approach (group A), 27 patients were treated with combined approach (group B). There was no significant difference in gender, age, injured side, cause of injury, time from injury to operation, preoperative hospital stay, preoperative visualanalogue scale (VAS) score, and intraoperative internal fixation between the two groups (P>0.05). All patients with Mason 2B avulsion subtype were treated by posterolateral approach, including 7 males and 10 females, aged from 25 to 68 years, with an average of 46.1 years. The operation time, intraoperative blood loss, postoperative hospital stay, and complications were recorded. The reduction quality was evaluated by Ovadia deals radiographic score, and the ankle function and pain were evaluated by VAS score, American Orthopaedic Foot and Ankle Society (AOFAS) score, and ankle range of motion. Results Mason 2B Pilon subtype: There was no significant difference in operation time, intraoperative blood loss, postoperative hospital stay, and follow-up time between the two groups (P>0.05). The radiological evaluation of Ovadia deals in group A was significantly worse than that in group B (P<0.05). The VAS score in the two groups significantly improved at each time point after operation, and the VAS score and AOFAS score further improved with the extension of time after operation, and the differences were significant (P<0.05). Except that the AOFAS score of group A was significantly lower than that of group B at last follow-up (P<0.05), there was no significant difference in VAS score and AOFAS score between the two groups at other time points (P>0.05). At last follow-up, the ankle range of motion in group A was significantly less than that in group B (P<0.05). There was no significant difference in the incidence of sural nerve injury, deep tissue infection, limitation of toe movement, and traumatic ankle arthritis between the two groups (P>0.05). Mason 2B avulsion subtype: The operation time was (119.47±20.61) minutes and the intraoperative blood loss was 50 (35, 55) mL. Seventeen patients were followed up 13-25 months, with an average of 18 months. The Ovadia deals score was excellent in 10 cases, good in 6 cases, and poor in 1 case at 1 week after operation, and the excellent and good rate was 94.1%. All fractures healed in 8-18 weeks with an average of 12.35 weeks. There were 1 case of sural nerve injury and 3 cases of traumatic ankle arthritis after operation. No deep tissue infection or limitation of toe movement occurred. The VAS score decreased significantly and AOFAS score increased significantly with time, and the differences were significant between different time points before and after operation (P<0.05). The ankle range of motion at last follow-up was (56.71±2.47)°. ConclusionCompared with the posterolateral approach, the combined approach is a better choice for the treatment of Mason 2B Pilon subtype. If the posteromedial bone block does not affect the reduction of the medial malleolus, the posterolateral approach can achieve good effectiveness for Mason 2B avulsion subtype.