Functional Outcome and Inflammatory Response of Patients with Extra-Articular Distal Humeral Fractures following Implantation of Anatomically Precontoured Locking Compression Plates through a Posterior Approach

Abstract

Distal humeral fractures are challenging injuries to surgically correct and account for up to 2% of all adult fractures. Surgical management of extra-articular distal humeral fractures is challenging considering surgical approach, implant selection, and position of the implant owing to the availability of different precontoured implants and plate configurations. Anatomically precontoured locking compression plates (APLCPs) allow the placement of angular stable screws right underneath the reduced joint surface fragments. To date, there is a lack of evidence supporting its superiority to conventional locking plate osteosynthesis (LPO) in treating extra-articular distal humeral fractures. The objective of the study is to evaluate the efficacy and safety of APLCPs in the treatment of extra-articular distal humeral fractures. A total of 100 patients diagnosed with humeral fractures and receiving treatments in our hospital between May 2018 and May 2020 fulfilled inclusion and exclusion criteria and were randomly assigned to LPO and APLCP groups according to the odd-even of the order of hospital admission, 50 cases per groups. Clinical endpoints were assessed including operation time; in-bed time; length of hospital stay; volume of intraoperative blood loss; VSA scores before and 24, 48, and 72 h after surgery; MEPS scores before and 3, 6, and 12 months after surgery; range of motion, flexion, and extension of the elbow; serum levels of CK, CRP, and IL-6; and incidence of complications after surgery. It was found that the APLCP group exhibited shortened operation time and in-bed time, decreased length of hospital stay, and reduced volume of intraoperative blood loss compared to the LPO group (all $P<0.001$ ). The two groups had declined VSA scores concomitant with increased MEPS scores after surgery in a time-dependent manner ( $P<0.001$ ). Notably, the VSA scores in the APLCP group were all lower than those in the LPO group at indicated time points (24, 48, and 72 h) after surgery ( $P<0.001$ ). Besides, the MEPS scores in the APLCP group were all higher than those in the LPO group at indicated time points (3, 6, and 12 months) after surgery ( $P<0.001$ ). It was revealed that the patients receiving extra-articular distal humeral APLCP through posterior approaches exhibited greater ranges of motion, flexion, and extension of the elbow than those receiving LPO after surgery ( $P<0.001$ ). The patients receiving extra-articular distal humeral APLCP through posterior approaches exhibited lower serum levels of IL-6, CRP, and CK than those receiving LPO after surgery (IL-6: $P=0.007$ , CRP: $P=0.001$ , CK: $P=0.001$ ). The APLCP had a lower total incidence rate of complication than the LPO group (48.00% vs. 18.00%, $P=0.003$ ). In conclusion, these data support the notion that the implantation of anatomically precontoured APLCP through a posterior approach allows for improved functional outcomes and attenuated inflammatory response and prevents the incidence of postoperative complications compared to conventional LPO for internal fixation of extra-articular distal humeral fractures.