Effects of metacarpal inclination angle and ulnar deviation angle on radius length shortening after distal radius fracture combined with internal fixation of ulnar styloid fracture / 国际外科学杂志

ABSTRACT

Objective:To investigate the effects of metacarpal inclination angle and ulnar deviation angle on radius length shortening after internal fixation of distal radius fracture combined with ulnar styloid fracture.Methods:A retrospective case-control study was conducted to analyze the clinical data of 84 patients with distal radius fracture complicated with ulnar styloid fracture treated by Beijing Daxing District People′s Hospital from February 2018 to January 2022. According to whether the ulnar styloid fracture was fixed or not, the patients were divided into two groups 18 patients with ulnar styloid fractures who were surgically fixed were in the fixation group, and 66 patients with ulnar styloid fractures who were not surgically fixed were in the non-fixation group. The perioperative indexes (operation time, intraoperative blood loss, surgical incision length), wrist joint function indexes [Gartland-Werley score, disability of the arm, shoulder, and hand (DASH) score, forearm rotation, ulnar deviation, metacarpal flexion, radial deviation, dorsal extension, grip strength] and complications (bone nonunion, osteolysis, ulnar pain, internal fixation failure, lower ulnar and radial instability, postoperative infection) were compared between the two groups. The changes of metacarpal inclination angle, ulnar deviation angle and distal radius distance of the two groups were analyzed by generalized estimation equation (GEE). The patients were followed up for 12 months, they were divided into two groups non-shortening group (radius shortening distance < 4 mm, n=61) and radius shortening group (radius shortening distance ≥ 4 mm, n=23) according to whether the radius shortening distance was ≥ 4 mm at the last follow-up. The influencing factors of postoperative radius shortening were evaluated by Logistic regression analysis. Results:Compared with the non-fixation group, the Gartland-Werley score(1.79±0.62 vs 4.65±0.97), DASH score (16.43±4.71 vs 28.72±6.06) and the incidence of complications (11.11% vs 39.40%) in the fixation group were significantly lower, and the forearm rotation angle [(81.29±6.60)° vs (70.79+ 5.15)°], ulnar deviation angle [(21.36±2.35)° vs (16.77±2.11)°], metacarpal flexion angle [(45.84±2.80)° vs (37.55±2.45)°] and dorsal extension angle [(50.23±5.16)° vs (40.65±3.580°] were significantly larger in the fixation group, all the differences were statistically significant ( P<0.05). GEE analysis and evaluation showed that treatment time, treatment plan and their interaction had significant effects on metacarpal inclination, ulnar deviation and distal radius ( P<0.05). The change of metacarpal inclination angle and ulnar deviation angle were independent influencing factors of radius shortening after internal fixation ( P<0.05). Conclusions:In the treatment of distal radius fracture combined with ulnar styloid fracture, internal fixation of distal radius combined with ulnar styloid process can improve wrist joint function, reduce the incidence of complications, and improve metacarpal inclination angle and ulnar deviation angle. A certain degree of radius shortening will occur after internal fixation. The changes of metacarpal inclination angle and ulnar deviation angle are the independent influencing factors of radius shortening after internal fixation.