Study On The Difference Between MIPO And ORIF In The Treatment Of Distal-third Humeral Fractures By Anterolateral Approach

Objective: To compare the clinical effects of MIPO(minimally invasive plate osteosynthesis)and ORIF(open reduction with internal fixation)by anterolateral approach for the treatment of distal-third humeral fractures,and to confirm the safety and feasibility of MIPO.Methods: From March 2005 to January 2018,a total of 90 patients with the distal-third humeral fractures were treated by anterolateral approach.The humeral shaft fractures were classified by AO/OTA fractures,including 21 cases of A1 type fracture,7 cases of A2 type fracture,14 cases of A3 type fracture,24 cases of B1 type fracture,12 cases of B2 type fracture,3 cases of B3 type fracture,5 cases of C1 fracture and 4 cases of C3 fracture.48 patients were treated with MIPO(MIPO group)and 42 patients were treated with ORIF(ORIF group).The genders,ages,mechanism of the injury,AO/OTA classification,operation time,hospitalization,intraoperative bleeding time,postoperative complications,the time of bone union,incision scar size,and postoperative limb function evaluation were compared between the two groups.The postoperative function results were evaluated by HSS(Hospital for Special Surgery)elbow scoring system and DASH(Disabilities of the Arm,Shoulder and Hand)scoring system.Results: All patients were followed up.The average of follow-up in MIPO group was16.9 months(range,13~25 months),and was 17.4 months(12~25 months)in ORIF group.There were no significant difference in intraoperative bleeding volume and hospitalization between the two groups(P>0.05).In MIPO group,the mean time of bone union was 13.47±1.349 weeks(range,11~16 weeks),one case of fracture delayed union healed completely 36 weeks after operation,no internal fixation failure and iatrogenic radial nerve injury.The mean degrees of elbow flexion was 132.1°±8.5°(range 95° ~135°),and the mean degrees of elbow extension was 0.62°±3.200°(range0°~20°).The mean points of HSS elbow joint score was 95.6.The mean points of DASH score was 4.5,and the mean length of the surgical scar was 6.7 cm(range 5~8.2cm).The mean time of bone union in ORIF group was 13.76±1.179 weeks(range 12~17 weeks).One case of fracture delayed union healed completely 32 weeks after operation.One case of nonunion was treated with iliac bone graft 36 weeks after operation.After 28 weeks of the second operation,the imaging showed complete fracture healing.Two patients suffered from iatrogenic radial nerve injury and recovered within 6 months after operation.The mean degrees of elbow flexion was131.9° ± 9.2°(range 95°~135°),and the mean degrees of elbow extension was 0.71° ±3.417°(range 0°~20°).The mean points of HSS elbow joint score was 94.1.The mean points of DASH score was 5.6,and the mean length of the surgical scar was 14.8 cm(range 12~20 cm).In the MIPO group,the postoperative recovery time of 5 patients with preoperative combined with radial nerve injury was 8.7 ± 3.9 weeks.In ORIF group,the postoperative recovery time of 6 patients with preoperative combined with radial nerve injury was 10.4±4.7 weeks.There were no postoperative complications such as the incision infection,the intractable pain or osteomyelitis in both groups.There was no significant difference in the HSS elbow joint score and the DASH score between the two groups(P>0.05).There were no significant difference between MIPO group and ORIF group in the postoperative effect of distal humerus fixation with 2 screws and 3screws(P>0.05).The average operation time of ORIF group and MIPO group were128.13 ± 36.251 and 134.04 ± 33.713 respectively,and the difference was not statistically significant(P>0.05).There was no significant difference in flexion and extension range of the elbow joint and fracture healing time between the two groups(P>0.05).All fractures healed in MIPO group,and no radial nerve injury cases were found after operation.The nonunion rate of fractures in ORIF group was 2.38%,and the incidence rate of iatrogenic radial nerve injury was 4.76%.The scar size of incision in MIPO group was much lower than that in ORIF group,and the patients’ postoperative satisfaction was high.Conclusion: Both MIPO and ORIF by the anterolateral approach has achieved satisfactory clinical effects in the treatment of distal-third humeral fractures,the patient recovered well after operation.MIPO has minimal incision and high patient satisfaction,which can be used as a good choice for the treatment of distal-third humeral fractures.