Risk Factors for Infection and Revision Surgery following Patellar Tendon and Quadriceps Tendon Repairs: An Analysis of 3,442 Patients

Abstract

Disruption of the extensor mechanism is debilitating with surgical repair being the accepted treatment. The incidence of infection and reoperation after extensor mechanism repair are not well reported in the literature. Thus, the objective of the current study was to (1) determine the incidence of surgical site infection and reoperation within 1 year of primary extensor mechanism repair and (2) identify independent risk factors for infection and reoperation following patellar and quadriceps tendon repair. A retrospective review of the 100% Medicare Standard Analytic files from 2005 to 2014 was performed to identify patients undergoing isolated patellar tendon repair and quadriceps tendon repair. Diagnosis of infection within 1 year of operative intervention and revision repair were assessed. Extensor mechanism injuries in the setting of total knee arthroplasty and polytrauma were excluded. Multivariate logistic regression analysis was performed to evaluate risk factors for postoperative infection and reoperation within 1 year. Infection occurred in 6.3% of patients undergoing patellar tendon repair and 2.6% of patients undergoing quadriceps tendon repair. Diabetes mellitus (odds ratio [OR] = 1.89, p = 0.005) was found to be an independent risk factor for infection following patellar tendon repair. Reoperation within 1 year occurred in 1.3 and 3.9% following patellar tendon and quadriceps tendon repair, respectively. Age less than 65 years (OR = 2.77, p = 0.024) and obesity (OR = 3.66, p = 0.046) were significant risk factors for reoperation after patellar tendon repair. Hypertension (OR = 2.13, p = 0.034), hypothyroidism (OR = 2.01, p = 0.010), and depression (OR = 2.41, p = 0.005) were significant risk factors for reoperation after quadriceps tendon repair. Diabetes mellitus was identified as a risk factor for infection after patellar tendon repair. Age less than 65 years, peripheral vascular disease, and congestive heart failure were risk factors for infection after quadriceps tendon repair. The current findings can be utilized to counsel patients regarding preoperative risk factors for postoperative complications prior to surgical intervention for extensor mechanism injuries.

Complications and re-operations after extensor mechanism repair surgery in a large cross-sectional cohort: females and tobacco-users at highest risk for adverse outcomes

“…Obesity and higher comorbidity scores were also found to be risk factors for postoperative complications in both QTR and PTR groups, which is consistent with prior reports [18, 20]. The effect of obesity on surgical outcomes has been well‐documented and could be related to issues associated with increased cardiopulmonary risks, nutrition and medication adjustments, and changes in instrumentation, surgical approach, and patient positioning [13, 23, 29].…”

“…The observed infection rate was higher in the PTR group compared to QTR (6.77% vs. 3.99%). Patellar tendon repairs tend to have higher rates of infection and wound issues compared with quadriceps tendon repairs given the less robust tissue envelope in the more distal aspect of the extensor mechanism [18, 25].…”

“…Despite a large body of work on the relationship between underlying medical comorbidities and risk for tendon rupture, there are few studies that have investigated the incidence of postoperative complications, readmissions, and revision repairs in patients who sustained tendinous extensor mechanism injuries and underwent either quadriceps tendon repair (QTR) or patellar tendon repair (PTR). In a retrospective review involving Medicare patients who underwent isolated PTR or QTR between 2005 and 2014, Lewis et al found infection rates of 6.3% and 2.6% in patients undergoing PTR and QTR, respectively [18]. One‐year reoperations were reported in 1.3% and 3.9% of patients following PTR and QTR, respectively [18].…”

“…In a retrospective review involving Medicare patients who underwent isolated PTR or QTR between 2005 and 2014, Lewis et al found infection rates of 6.3% and 2.6% in patients undergoing PTR and QTR, respectively [18]. One‐year reoperations were reported in 1.3% and 3.9% of patients following PTR and QTR, respectively [18]. However, because patients suffering from tendinous extensor mechanism injuries are expected to be younger with fewer comorbidities, an analysis based solely on Medicare patients may not be fully representative of the true population.…”

Knee

“…This take home message for this cohort of 3,442 Medicare patients, led by investigators from Charlottesville (Virginia, USA) , has demonstrated failure rates of 1% for patella tendon and 4% for quads tendon ruptures. 5 Overall, when analyzing risk factors for revision surgery, age younger than 65 years and obesity were risk factors for reoperation in patellar tendon injuries. Hypertension, hypothyroidism, and depression were risk factors for quads ruptures.…”