Surgeon volume and the risk of deep surgical site infection following open reduction and internal fixation of closed tibial plateau fracture

Abstract

Background: Emerging evidences supported that the surgeon case volume significantly affected post-operative complications or outcomes following a range of elective or non-elective orthopaedic surgery; no data has been available for surgically treated tibial plateau fractures. We aimed to investigate the relationship between surgeon volume and the risk of deep surgical site infection (DSSI) following open reduction and internal fixation (ORIF) of closed tibial plateau fracture.

Methods: This was a further analysis of the prospectively collected data. Adult patients undergoing ORIF procedure for closed tibial plateau fracture between January 2016 and December 2019 were included. Surgeon volume was defined as the number of surgically treated tibial fractures in the preceding 12 months and dichotomized on the basis of the optimal cut-off value determined by the receiver operating characteristic (ROC) curve. The outcome was DSSI within one year post-operatively. Multiple multivariate logistic models were constructed for "drilling down" adjustment of confounders. Sensitivity and subgroup analyses were performed to assess the robustness of outcome and identify the "optimal" subgroups.

Results: Among 742 patients, 20 (2.7%) had a DSSI and 17 experienced re-operations. The optimal cut-off value for case volume was nine, and the low-volume surgeon was independently associated with 2.9-fold (OR, 2.9; 95%CI, 1.1 to 7.5) increased risk of DSSI in the totally adjusted multivariate model. The sensitivity analyses restricted to patients with original BMI data or those operated within 14 days after injury did not alter the outcomes (OR, 2.937, and 95%CI, 1.133 to 7.615; OR, 2.658, and 95%CI, 1.018 to 7.959, respectively). The subgroup analyses showed a trend to higher risk of DSSI for type I-IV fractures (OR, 4.6; 95%CI, 0.9 to 27.8) classified as Schatzker classification and substantially higher risk in patients with concurrent fractures (OR, 6.1; 95%CI, 1.0 to 36.5).

Conclusion: The surgeon volume is independently associated with the rate of DSSI, and a number of ≥ nine cases/year are necessarily kept for reducing DSSIs; patients with concurrent fractures should be preferentially operated on by high-volume surgeons.

Keywords: Case volume; Deep surgical site infection; Outcome–volume relationship; Tibial plateau fracture.