Effect of minimally invasive plate osteosynthesis through two approaches on bone metabolic activity and radial nerve injury in patients with humeral midshaft fracture

Abstract

OBJECTIVE To compare application of minimally invasive plate osteosynthesis (MIPO) through two approaches for patients with humeral midshaft fracture, and analyzes the effect on bone metabolic activity and radial nerve injury. METHODS From April 2014 to May 2017, 76 patients with humeral midshaft fracture treated by MIPO were selected and randomly divided into group A (anterior approache group) and group B (lateral approach group) according to random number stable. In group A, there were 38 patients including 22 males and 16 females, aged from 18 to 74 years old with an average age of(48.21±5.79) years old; 24 patients were caused by traffic accidents, 6 patients were caused by heavy object crushing, 8 patients were caused by falling down; 20 patient were on the right side, 18 patients were on the left side; 15 patients were type A, 17 patients were type B, 6 patients were type C according to AO classification; the patients were treated by MIPO through anterior approach. In group B, there were 38 patients including 23 males and 15 females, aged from 20 to 73 years old with an average age of(48.40±5.81) years old; 26 patients were caused by traffic accidents, 5 patients were caused by heavy object crushing, 7 patients were caused by falling down; 17 patients were on the right side, 21 patients were on the left side; 15 patients were type A, 18 cases were type B, 5 cases were type C according to AO classification; the patients were treated by MIPO through lateral approach. Intraoperative blood loss, operative time, hospital stays, fracture healing time between two groups were compared. Bone gla protein (BGP), collagen C-terminal peptide (CTX) and osteoprotegerin (OPG) were tested before and after operation. The incidence of radial nerve injury after operation was observed. RESULTS All patients were followed-up from 12 to 18 months with an average of (15.4±2.1) months. There were no statistical differences in operative time, intraoperative blood loss between two groups. Hospital stays, fracture healing time in group A were(6.52±1.81) d, (13.27±3.01) weeks respectively, while in group B were(9.61±1.99) d, (14.83±3.08) weeks; and had differences between two groups. There were no differences in BGP, OPG and CTX, BGP between two groups and OPG in group A at 1 month after operation were(7.10±0.58) ng/ml, (173.67±9.12) pg/ml and higher than that of group B(6.63±0.62) ng/ml, (152.80±9.23) pg/ml; while CTX in group A (224.52±12.67) μg/ml was lower than that of group B(259.13±13.54) μg/ml(P<0.05). No patient occurred radial nerve injury in group A, 4 patients occurred radial nerve injury in group B, and had statistical differences between two groups(χ²=4.220, P<0.05). CONCLUSIONS Compared with lateral approach, anterior approach has much more effective in minimally invasive MIPO for humeral shaft fractures, which could improve bone metabolism and reduce risk of radial nerve injury.