Outcomes of operative management of humerus fracture nonunion among adults attending Moi Teaching and Referral Hospital, Eldoret, Kenya

Abstract

Background: Humeral fracture account for 5-8% of all fractures in adults. Most of these fractures tend to heal; however, up to 33 % will develop nonunion which is failure of fracture healing in consecutive 9 months without intervention. Humeral fracture nonunion causes major functional disability, chronic pain and reduced quality of life. The incidence of humerus fracture nonunion cases at the Moi Teaching and Referral Hospital (MTRH) has increased by 25% in the last five years. Data on the functional outcomes of operational management of humeral fracture nonunion at MTRH are scanty. This study intends to close the knowledge gap and advance the field. Objective: To evaluate the outcomes of operative management of humeral fracture nonunion among adult patients attending the Moi Teaching and Referral Hospital, Eldoret Kenya. Methods: This study was a hospital based descriptive prospective study involving 32 adult patients with humerus fracture nonunion attending the MTRH, Orthopedics unit. Upon meeting ethical considerations, patients who met inclusion criteria and consented were recruited and followed up for a period of 12 months (September, 2021-August, 2022). Data was collected using a structured interviewer administered questionnaire, the Non-Union Scoring System (NUSS) and the American Shoulder and Elbow Surgeons (ASES) Score sheets. The demographic characteristics, the initial injury patterns, operative modalities used and union rate were recorded and analyzed. The functional outcomes were assessed using the ASES score tool at 6, 12, 18 and 24 weeks after the operation. Results: The mean age was 52.2 years (SD: 11.84) with male predominance. The left hand was more injured than the right (59.4%). Cigarette smoking and alcohol use were recorded in 9 and 17 respondents respectively. The humerus shaft was the most affected site (18, 56.25%). The mechanism of injuries was Road Traffic Accident (26), falls (4) and physical assaults (2). The mean time to diagnosis of nonunion was 10 months (SD: 1.9). The mean NUSS score was 23.34 points (SD: 3.15). Open Reduction Internal Fixation (ORIF) plating and autologous bone grafting were used in all the patients. Union rate of 96.2% was achieved at mean time of 21 weeks (SD: 4.5). The mean ASES score at week 6 and week 24 was 29.89 points (SD: 12.67) and 78.98 points (SD:6.86) respectively. Surgical wound infection and radial nerve palsy was encountered in 3(9.3%) and 2(6.25%) respectively. Bivariate analysis using Fischer’s exact test showed no association between smoking, alcohol use, gender and improved ASES (p >0.05). Younger age and earlier diagnosis of humerus nonunion were associated excellent union (p<0.05). Conclusion: A union rate of 96.2% and improved functional outcomes with few complications was achieved following the use of ORIF plating with autologous bone graft in the operative management of humerus nonunion at MTRH. Recommendations: The use of rigid plate fixation with autologous bone grafting is recommended in the operative management of humerus fracture nonunion as it is associated with good functional outcomes. Further studies are needed to evaluate long term functional outcomes