The Impact of the Soong Index on Hardware Removal and Overall Reoperation Rates After Volar Locking Plate Fixation of Distal Radius Fractures.

Purpose: This study sought to determine the impact of volar plate prominence on reoperation rates after open reduction and internal fixation of distal radius fractures with volar locking plates and to identify other factors associated with removal of hardware (ROH) or a reoperation.

Methods: A retrospective study of patients who underwent distal radius open reduction and internal fixation between 2012 and 2016 at 2 level I trauma centers was conducted. Plate prominence was evaluated using the Soong index at the first postoperative visit. The details of patient demographics, fracture and plate characteristics, complications, and reoperations were recorded. Bivariate and multivariable regression analyses were used to identify factors associated with increased rates of ROH and overall reoperation.

Results: A total of 732 (70.2%) of 1,042 patients completed follow-up at an average of 38.2 months, including 34 patients with bilateral operations, yielding 766 distal radius fractures. One hundred sixteen (15.1%) patients underwent reoperation at an average of 12.1 ± 13.6 months after the index surgery. Removal of hardware was the most commonly performed reoperation (77 patients, 10%). The multivariable regression analysis revealed significantly higher rates of ROH in Soong grade 1 or 2 patients (odds ratio 16, 95% CI 5.8-47; odds ratio 44, 95% CI 14-140, respectively) than in Soong grade 0 patients. Plate type, younger age, bilateral injuries, and concomitant procedures at the time of the index operation were all associated with increased risk of ROH. There were significant differences between individual surgeons the in rates of ROH (range 2.1%-22%) and overall reoperation (range 5.2%-36%). Compared with other hand surgeons, fellowship-trained hand surgeons had lower rates of ROH (8% vs 14%, respectively) and overall reoperation (12% vs 22%, respectively).

Conclusions: The rates of ROH and overall reoperation increase with increasing Soong grade. Plate type is independently predictive of future ROH. Older patients and those undergoing open reduction and internal fixation experience lower rates of subsequent reoperation.

Type Of Study/level Of Evidence: Prognostic IV.