OTA 2004 Posters
Prognostic Factors Affecting Functional Outcome after Surgical Treatment of Humeral Shaft Fracture Nonunion
Purpose: Nonunion of a fracture of the humeral shaft can be extremely disabling with profound effects on a patient's independent functioning. The purpose of this study was to evaluate the functional outcome and to identify prognostic factors that influence the healing time of surgically treated humeral shaft fracture nonunions.
Methods: We performed a retrospective analysis and identified 53 consecutive patients treated surgically at a level one trauma center for nonunion of a humeral shaft fracture. Six patients had died, 3 refused to participate, 6 were lost to follow-up, and 38 patients (18 men and 20 women with a mean age of 55 years) were evaluated at a mean follow-up of 60 months. The mechanisms of injury were a fall (24 patients), a motor vehicle accident (11 patients), and an industrial accident (3 patients). All patients with atrophic nonunion (31) were surgically treated with compression plating and bone grafting: 7 patients with hypertrophic nonunion were treated with plating alone. All patients underwent a comprehensive assessment including the completion of the Short Form 36 (SF-36), the Disabilities of Arm, Shoulder and Hand (DASH), and the Short Musculoskeletal Functional Assessment (SMFA), as well as the determination of the Constant shoulder and Mayo elbow scores.
Results: On the basis of their tobacco-smoking habits during the time to union (time from operation to radiographic union), patients were classified as 'non-smokers' or 'smokers'. Seventeen (44.7%) patients were smokers and 21 (55.3%) were non-smokers. The demographic characteristics of the two groups were similar. All nonunions united, with the mean time to union of 16.2 weeks for non-smokers and 25.1 weeks for smokers (P <0.001). All nonunions united within 35 weeks of surgery. Time to union was negatively associated with the Physical Function portion of the SF-36 (P = 0.01), the DASH (P = 0.01), and the Arm and Hand Function part of the SMFA (P = 0.005). The only other factor that had a significant negative effect on the functional outcome scores was the presence of one or more comorbid factors (SF-36, P <0.001; DASH, P <0.001; SMFA, P <0.001). Patient-oriented and surgeon-based scores were found to correlate well (range, r = 0.545 to r = 0.916, P <0.001 for all combinations).
Conclusions/Significance: These results indicate that time to consolidation of operatively treated humeral shaft nonunions was significantly longer for smokers compared with non-smokers. Increased time to union was also associated with lower patient-reported functional outcome scores. The long-term functional outcome after surgical treatment of humeral shaft nonunions is dependent upon the time to consolidation. Smoking is a significant remediable risk factor for delayed union after surgical repair. Given the adverse effects of smoking on bony union, orthopaedic surgeons should emphasize abstention during the full rehabilitation period.