Humeral shaft fractures account for about 1% of all fractures.1 With the exception of the few absolute indications for surgical intervention, such as the presence of an open fracture, the current teaching on treatment of these fractures is that the majority can be successfully managed nonoperatively.1-3 These conservative measures consist of bandages, abduction splints, U-casts, hanging arm casts, and, most commonly, functional bracing, which is considered the gold standard for treatment of humeral shaft fractures by many authors.1-3 One of the most often cited disadvantages of nonoperative management over surgical treatment is the higher incidence of residual deformity, the most common of which is varus angulation.4
The incidence of malunion (>20° of angulation in any plane or shortening of ≥2.5 cm) after nonoperative treatment varies in the literature from 0% to 13%,2,4-9 with a recent literature review documenting a mean incidence of 4.4% within the frontal plane and 2% within the sagittal plane across all studies.2 As reported initially by Sarmiento and colleagues3,9 and echoed by other authors,2,5,8 angular deformity of less than 20° is thought to be both cosmetically and functionally acceptable. Whether angular deformities or malunion of more than 20° actually leads to functional limitations is unknown. Although some observational reports suggest that the degree of radiographic malalignment does not necessarily correlate with functional outcome,8 no studies have specifically evaluated patient outcomes of humeral shaft fracture malunions.
We conducted a study to determine the overall incidence and long-term clinical and functional outcomes of patients with malunion after nonoperative management of humeral shaft fractures. Long-term outcomes were assessed with current symptoms, physical examination findings, need for subsequent operative intervention, DASH (Disabilities of the Arm, Shoulder, and Hand) scores, and a self-reported questionnaire. We hypothesized that patients who develop a malunion after nonoperative treatment of a closed humeral shaft fracture will have satisfactory functional outcomes based on subjective reports, physical examination findings, and DASH scores.
Methods
After obtaining institutional review board approval for the study, we selected patients from a retrospective medical record review of all those 18 years or older with a humeral shaft fracture managed nonoperatively at our institution between January 1, 2001, and June 30, 2012, with a minimum 1-year follow-up. We identified 156 patients with nonoperatively managed midshaft humerus fractures. Study exclusion criteria included fracture associated with a tumor (3 patients), ipsilateral upper extremity injury (9), open/ballistic injury (18), nonunion (9), underlying cognitive disability or psychiatric illness (4), and insufficient follow-up to clinical or radiographic healing (22). Ninety-one patients were eligible for study inclusion. Radiographs at time of final clinical visit were reviewed to assess for evidence of malunion at the fracture site, as defined by previously reported criteria3 (>20° angulation in anterior/posterior or varus/valgus plane of motion or shortening of ≥2.5 cm). Fifteen patients met all the inclusion criteria for further evaluation.
Medical records were retrospectively reviewed for information on age at injury, sex, comorbidities (eg, diabetes, osteoporosis, smoking), body mass index, type and duration of immobilization, complications, return to work, cosmetic perception, time to final clinical follow-up, and symptoms at final clinical follow-up. Incidence of potential risk factors associated with malunion—obesity, noncompliance, and comorbidities such as smoking and diabetes—was compared between the 15 patients with malunion and the other study patients, who healed without malunion.
For long-term postoperative follow-up, patients were contacted to be seen in clinic to complete an updated physical examination, self-reported questionnaire, and the DASH form. Physical examination included measurements of range of motion (ROM) and strength involving the shoulder, elbow, and forearm, with ROM reported as the difference between the injured and contralateral upper extremities. Neurovascular status and focal tenderness to palpation were also assessed on examination. When in-person examination was not possible, the questionnaire and DASH form were completed over the telephone. The self-reported questionnaire asked for information on smoking status, pain, functional limitations, cosmetic perception, satisfaction, and whether or not the patient would still opt for nonoperative management if presented with the same injury again. Pain and satisfaction were measured on numerical scales: Pain scores ranged from 0 (no pain) to 10 (worst possible pain), and satisfaction scores ranged from 1 (not satisfied) to 5 (very satisfied). Data are presented as mean values.
Results
Of the 91 study-eligible patients, 15 (16%) met the radiographic criteria for the diagnosis of malunion. Retrospective data were available for all 15 patients from time of injury to final clinical follow-up (mean, 19 weeks; range, 7-53 weeks). Mean age at injury was 39 years (range, 20-79 years). Additional demographics are listed in Table 1. Incidence of potential risk factors, such as body mass index (26.5 vs 25.4), smoking (33% vs 33%), and diabetes (0% vs 8%), was not significantly different between the malunion and healed-without-malunion groups, respectively. Furthermore, all malunion patients were compliant with their treatment protocol.
