[A comparative study on open reduction and plating osteosynthesis and minimal invasive plating osteosynthesis in treating mid-distal humeral shaft fractures].

OBJECTIVE: To compare the clinical results of two plating osteosynthesis techniques, open reduction and plating osteosynthesis (ORPO) and minimal invasive plating osteosynthesis (MIPO), in surgical treatment of mid-distal humeral shaft fractures.

METHODS: From March 2004 to October 2006, 40 cases of closed unilateral mid-distal humeral shaft fractures were surgically treated with MIPO or ORPO. In the MIPO treated group (n = 19), there were 14 males and 5 females, with a mean age of 39.05 years. Fractures involved in middle humeral shaft in 10 cases and distal fragment in 9 cases. According to OTA classification, there were 3 cases of type A, 13 cases of type B and 3 cases of type C. Four cases complicated by radial nerve palsies. In the ORPO treated group (n = 21), there were 13 males and 8 females with a mean age of 39.05 years, including 14 cases of type A and 7 cases of type B fractures according to OTA classification. The fractures involved in middle humeral shaft in 13 cases and distal fragment in 8 cases. Five cases complicated by radial nerve palsies. The time from injury to operation in both groups were 2 to 14 days. For patients in the MIPO group, fractures were closely reduced and fixated with an anterior placed plate inserted through two small incisions made at the anterior side of arm, away from fracture sites. The radial nerves were not exposed. For patients in the ORPO group, fractures were exposed, reduced, and fixated with an anterolateral or a posterior positioned plate after careful dissection and protection of radial nerve through an anterolateral or a posterior approach. The operation time, the occurrence of iatrogenic radial nerve palsy and the bone healing time were recorded. The functions of the affected shoulders and elbows were evaluated with UCLA end-result score and Mayo elbow perform index (MEPI), respectively.

RESULTS: All the wounds in both groups healed primarily. There was no iatrogenic radial nerve palsies in the MIPO group after surgery; however, 5 cases of transient iatrogenic radial nerve palsies were identified in the ORPO group after surgery, and the function of radial nerve recovered in these cases at the last follow-up. Eighteen cases were followed up 14-44 months (mean 25.44 months) in MIPO group, and 19 cases were followed up 13-48 months (mean 32.11 months) in ORPO group. The mean bone healing time was 17.06 (12-32) weeks in MIPO group and 16.11 (8-58) weeks in ORPO group, showing no significant difference between two groups (P > 0.05). There was no nonunion and hardware failure in both groups. The mean forward flexion of the shoulder was 166.94 degrees (150-170 degrees) in MIPO group and 164.74 degrees (130-170 degrees) in ORPO group. The mean UCLA shoulder score was 34.78 (33-35) points in MIPO group and 34.42 (30-35) points in ORPO group. The mean range of motion of the elbow in MIPO and ORPO groups was 133.33 degrees (120-140 degrees) and 136.7 degrees (120-140 degrees), respectively. The MEPI in these two groups was 99.44 (90-100) and 99.74 (95-100) points, respectively. There was no statistically significant difference between two groups in all indexes mentioned above.

CONCLUSION: The good results could be obtained when ORPO and MIPO technique are applied to treat mid-distal humeral shaft fractures. MIPO technique has advantages to not expose the radial nerve and to decrease the occurrence of iatrogenic radial nerve palsies.