THE IMPACT OF HAND DOMINANCE ON FUNCTIONAL RECOVERY FOLLOWING UPPER EXTREMITY INJURIES

Hand dominance is an important component of the history for patients with upper extremity injuries; however, the impact that this actually has on patient functional recovery and outcomes is unclear. The few studies that have examined the relationship between hand dominance and outcomes following upper extremity injury have reported mixed results. Furthermore, the effect of hand dominance appears to be mediated by factors such as age, sex, and operative versus nonoperative management. The primary aim of this study was to determine the role that hand dominance plays in patient recovery following operative and nonoperative management of upper extremity injuries. This study is a retrospective subgroup analysis of three previous multi-centre prospective randomized clinical trials (RCT; Humeral Diaphyseal RCT, PERK 1 RCT, Ulnar Diaphyseal RCT). Patient and injury characteristics including age, sex, injury classification, and management (operative vs. non-operative) were collected. Common clinical outcomes across all three RCTs included range of motion and grip strength), patient reported outcomes included the Disability Shoulder, Arm, Hand (DASH) score, Pain Visual Analogue Scale (VAS), and return to work. Wilcoxon rank sum tests and Person's Chi-squared tests were used, as appropriate. A multiple variable repeated measures regression analysis will be performed to determine what variables are predictive of patient-reported outcome scores with the variable of interest being if the dominant arm was injured. Survival analysis will be used to evaluate the effect of hand dominance on return to work. A total of 421 patients across the three RCTs met inclusion criteria, with 72% of participants being male in the Ulnar Diaphyseal RCT, 61% being male in the Humeral Diaphyseal RCT, and 51% being male in the PERK 1 RCT. The dominant upper extremity was injured in 55% of those in the Humeral Diaphyseal RCT and in 45% of the PERK 1 RCT. The DASH scores were statistically significantly lower if the dominant extremity was injured at the 2-week follow-up [59 (± 20) for dominant side injured compared with 53 (± 21); p = 0.029]. However, at subsequent follow-ups at 6 weeks, 6 months, and 12 months, there was no difference in DASH score between the side of the extremity injury. Interestingly, DASH scores were significantly improved for those in the PERK 1 RCT (elbow fractures and dislocations) compared with the Humeral Diaphyseal RCT (isolated humeral diaphyseal injuries) at the 2- (p the rate of DASH improvement over time will also be completed. Although hand dominance is routinely collected during patient assessment, the influence of injury to the dominant upper extremity on outcomes is poorly understood following upper extremity trauma. This study found more significant early impairment if the dominant arm was injured, but this did not persist at the 6-week follow-up assessment. This novel data from three large multi-centre RCTs will help inform post-injury patient counselling regarding expectations for functional recovery after upper extremity injuries.