Delayed fixation of displaced midshaft clavicle fractures reduces muscle endurance

If treated immediately, patients with midshaft clavicle fractures show improved outcome scores.

CHICAGO — Delaying reconstruction of displaced midshaft clavicle fractures can significantly reduce abduction and flexion endurance by about 30%.

Still, patients in a recent study at St. Michael’s Hospital in Toronto experienced restored shoulder strength similar to that of patients treated with immediate fixation.

Researchers found that patients immediately treated with fixation for their displaced midshaft clavicle fractures restored 100% of their flexion and abduction endurance. These patients also showed slightly better Disabilities of the Arm, Shoulder and Hand (DASH) scores and performed statistically significantly better than delayed reconstruction patients in the Constant Shoulder Score, said Jeffrey M. Potter, a research assistant at St. Michael’s Hospital.

“We believe that this information can be used to advise patients with a displaced midshaft clavicle fracture of the treatment options available to them, and to compare the results of delayed vs. immediate intraoperative intervention,” Potter said at the American Academy of Orthopaedic Surgeons 73rd Annual Meeting.

Immediate vs. delayed

Potter and his colleagues evaluated 29 patients with closed, isolated and completely displaced midshaft clavicle fractures. The same surgeon treated all patients and placed them into either the acute reconstruction group or delayed reconstruction group, Potter said.

The acute group included 15 fractures, treated with open reduction and internal compression plate fixation at a mean 0.6 months after fracture. The surgeon randomized 14 patients to the delayed group. All delayed group patients suffered from malunion or nonunion and underwent open reduction and compression plate fixation at a mean 66 months after fracture, Potter said.

There was no significant difference between groups with respect to gender, age, fracture of the dominant limb or fracture mechanism, he added.

The researchers conducted follow-up assessment at a mean 25 months postop when patients had achieved clinical and radiographic union.

In addition to the DASH and Constant Shoulder questionnaires, the investigators also conducted objective muscle strength and endurance tests using the Baltimore Therapeutic Equipment (BTE) Work Stimulator. Patients subjectively rated their satisfaction with the surgery on a scale of 0 (extreme dissatisfaction) to 10 (extreme satisfaction).

Few differences

“Straight recovery was excellent for both groups in shoulder flexion (P=.56), abduction (P=.75), external rotation (P=.29) and internal rotation (P=.87),” Potter said. “The acute group experienced improved recovery in each case. However, none of these differences were significant.”

But muscle endurance results showed a significant difference between the two groups. “We found that delayed fixation led to a significant residual loss in shoulder flexion and abduction endurance,” Potter said. Acute group patients regained 107% of flexion, compared to 71.1% of flexion regained in the delayed patient group (P=.05).

Abduction endurance results were not statistically significant (P=.21).

Mean DASH scores, measuring disability level, were 7.7 for the delayed group and 3 for the acute group patients (P=.13). This difference was also not significant, Potter said.

Measuring shoulder function, mean Constant Shoulder Scores were 88 in the delayed group and 95 in the acute group (P=.012). “This seven-point difference between the two groups was significant,” Potter said.

Both the delayed group and the acute group rated their satisfaction as excellent: 9.5 out of 10 in the delayed group and 9.8 in the acute group.

“The limitations of this study included large variability between the patients, small sample size and the potential for selection bias,” Potter said.

For more information:
Potter J, McKee M, Schemitsch E. Immediate fixation vs. delayed reconstruction of displaced mid-shaft fractures of the clavicle. #069. Presented at the American Academy of Orthopaedic Surgeons 73rd Annual Meeting. March 22-26, 2006. Chicago.