Robinson and colleagues measured how often clavicle fractures managed without surgery remained ununited at 24 weeks and which patient and injury factors predicted nonunion.
Prospective observational cohort of 868 consecutive patients at an Edinburgh trauma unit, January 1997 to March 2001, reviewed at 6, 12 and 24 weeks.
Methods
Design
Prospective observational cohort
Consecutive patients, January 1997 to March 2001
Data source
Dedicated clavicle review clinic, Edinburgh orthopaedic trauma unit
Sole acute musculoskeletal trauma service for the local adult population
Patients
868 patients (638 men, 230 women)
Median age 29.5 years
581 diaphyseal fractures
263 lateral‑fifth fractures
24 medial‑fifth fractures
8 excluded for immediate surgery
42 nonlocal residents excluded
Exposure
Collar and cuff sling for comfort for 2 weeks
Active shoulder movement encouraged
Physiotherapy only for stiffness at 6 weeks
Follow-up
Clinical and radiographic review at 6, 12 and 24 weeks
206 patients (23.7%) lost before the 24‑week review
Outcomes
Nonunion: no pain‑free stability and no bridging callus at 24 weeks
Risk factors by univariate and multivariate analysis
Key Findings
Overall, 6.2% of fractures were still ununited at 24 weeks (95% CI 4.2% to 8.3%): 11.5% of lateral‑end, 8.3% of medial‑end and 4.5% of diaphyseal fractures.
After a diaphyseal fracture, older age, female sex, displacement and comminution each raised nonunion risk and stayed independent predictors on multivariate analysis (p < 0.05).
After a lateral‑end fracture, only older age and displacement raised nonunion risk, and both remained independent on multivariate analysis (p < 0.05).
Displaced medial‑end fractures had a higher nonunion rate than nondisplaced ones (14.3% vs 6.7%), but the difference was not significant given the small numbers.
Injury mechanism predicted diaphyseal nonunion on its own but was not an independent predictor once the other factors were adjusted for.
From the final diaphyseal model, a prognostic index can be calculated for each patient and converted into the probability of nonunion at 6, 12 or 24 weeks.
Board pearl
For diaphyseal fractures, the displacement that predicted nonunion was complete loss of cortical contact, and measured angulation, translation or shortening added no significant predictive power.
Authors' conclusion
Nonunion at 24 weeks after a clavicular fracture is an uncommon occurrence, although the prevalence is higher than previously reported. There are subgroups of individuals who appear to be predisposed to the development of this complication, either from intrinsic factors, such as age or gender, or from the type of injury sustained. The predictive models that we developed may be used clinically to counsel patients about the risk for the development of this complication immediately after the injury.
Robinson and colleagues measured how often clavicle fractures managed without surgery remained ununited at 24 weeks and which patient and injury factors predicted nonunion.
Prospective observational cohort of 868 consecutive patients at an Edinburgh trauma unit, January 1997 to March 2001, reviewed at 6, 12 and 24 weeks.
Methods
Design
Prospective observational cohort
Consecutive patients, January 1997 to March 2001
Data source
Dedicated clavicle review clinic, Edinburgh orthopaedic trauma unit
Sole acute musculoskeletal trauma service for the local adult population
Patients
868 patients (638 men, 230 women)
Median age 29.5 years
581 diaphyseal fractures
263 lateral‑fifth fractures
24 medial‑fifth fractures
8 excluded for immediate surgery
42 nonlocal residents excluded
Exposure
Collar and cuff sling for comfort for 2 weeks
Active shoulder movement encouraged
Physiotherapy only for stiffness at 6 weeks
Follow-up
Clinical and radiographic review at 6, 12 and 24 weeks
206 patients (23.7%) lost before the 24‑week review
Outcomes
Nonunion: no pain‑free stability and no bridging callus at 24 weeks
Risk factors by univariate and multivariate analysis
Key Findings
Overall, 6.2% of fractures were still ununited at 24 weeks (95% CI 4.2% to 8.3%): 11.5% of lateral‑end, 8.3% of medial‑end and 4.5% of diaphyseal fractures.
After a diaphyseal fracture, older age, female sex, displacement and comminution each raised nonunion risk and stayed independent predictors on multivariate analysis (p < 0.05).
After a lateral‑end fracture, only older age and displacement raised nonunion risk, and both remained independent on multivariate analysis (p < 0.05).
Displaced medial‑end fractures had a higher nonunion rate than nondisplaced ones (14.3% vs 6.7%), but the difference was not significant given the small numbers.
Injury mechanism predicted diaphyseal nonunion on its own but was not an independent predictor once the other factors were adjusted for.
From the final diaphyseal model, a prognostic index can be calculated for each patient and converted into the probability of nonunion at 6, 12 or 24 weeks.
Board pearl
For diaphyseal fractures, the displacement that predicted nonunion was complete loss of cortical contact, and measured angulation, translation or shortening added no significant predictive power.
Authors' conclusion
Nonunion at 24 weeks after a clavicular fracture is an uncommon occurrence, although the prevalence is higher than previously reported. There are subgroups of individuals who appear to be predisposed to the development of this complication, either from intrinsic factors, such as age or gender, or from the type of injury sustained. The predictive models that we developed may be used clinically to counsel patients about the risk for the development of this complication immediately after the injury.