Fibular strut allograft influences reduction and outcomes after locking plate fixation of comminuted proximal humeral fractures in elderly patients: a retrospective study

Abstract Abstract Background: Proximal humeral fractures (PHFs) are the third most commonly occurring fractures in elderly patients. Most of these fractures can be treated with conservative methods, but the optimal surgical treatment strategy for unstable fractures in elderly patients remains controversial. This study aimed to compare the radiological and clinical outcomes between locking compression plate (LCP) fixation and LCP fixation with fibular allograft implantation for the treatment of comminuted PHFs. Methods: A retrospective review was performed on 60 three- and four-part PHFs . The outcomes were assessed for 35 patients in the LCP group and 25 in the LCP with fibular allograft (FA) group, with a mean age of 72.75 years (60 to 88), at a mean follow-up of 31.95 months (24 to 40). Fracture reduction was quantitatively determined by humeral head height (HHH) and neck-shaft angle (NSA). Loss of anatomic fixation was defined if the varus malalignment of the neck-shaft angle (NSA) was more than 5° or if the change in HHH was more than 3 mm. The clinical outcome was evaluated by Constant-Murley score (CMS) and American Shoulder and Elbow Surgeons (ASES) score. Result: The average radiological changes were higher in the LCP group than in the locking plate with fibular allograft group (HHH of 4.16 mm vs 1.18 mm [p<0.001] and NSA of 9.94° versus 3.12° [p﹤0.001 ]). The final average outcome scores were lower in the LCP group than in the FA group (CMS of 73.00 vs 78.96 [p=0.024] and ASES score of 72.80 vs 78.64 [p=0.022]). The FA group showed better forward elevation (p=0.010) and abduction (p=0.002); however, no significant differences were observed for shoulder external rotation or internal rotation. The number of complications was higher in the LCP group (28.57%) than in the FA group (1.2%) (p<0.001). Conclusion: For comminuted PHFs in elderly patients, locking plate fixation with a fibular strut allograft showed satisfactory radiological and clinical outcomes. Trial registration: ZDYJLY(2018)New-9. Name of registry: IEC for clinical Research of Zhongda Hospital, Affiliated to Southeast University. URL of registry: http://www.njzdyy.com. Date of registration: 2018-05-17 Key words: proximal humeral fracture; fibular allograft; locking plate; elderly patients