Thirty-Day Complications in Osteonecrosis Patients Following Total Hip Arthroplasty

Thirty-day complications in osteonecrosis (ON) patients undergoing total hip arthroplasty (THA) are inconsistently reported. Therefore, the purpose of this study is to evaluate (1) the incidence of THA, (2) operative times, (2) length of stay, (3) reoperation rates, (4) readmission rates, and (5) complication rates, in the general vs ON THA populations. We also substratified and compared these cohorts based on ON-specific risk factors.

Using the National Surgical Quality Improvement Program database, Current Procedural Terminology code 27130, International Classification of Disease, Ninth Edition code 733.42, and a 1:1 propensity score match, a total of 8344 matched ON and non-ON THA patients were identified. ON patients were also substratified based on key risk factors. The above variables were compared between the matched ON and non-ON cohorts as well as for patients with each risk factor using Pearson's chi-square and Student t-tests.

The proportion of THAs performed on ON patients decreased by 35% from 2008 to 2015. Mean operative times were constant between the ON and non-ON patients (102 minutes). ON patients had shorter mean length of stay (3.1 vs 3.4 days, P = .002). Of the 17 different 30-day complications evaluated, superficial surgical site infection (1.2% vs 0.6%, P = .004), pneumonia (0.8% vs 0.2%, P = .001), transfusion (15.6% vs 5.4%, P < .001), and readmission (5.1% vs 2.3%, P = .012) were higher among ON patients. ON patients with a history of corticosteroid use, higher American Society of Anesthesiologists score, and smoking were also found to have higher complication rates compared to non-ON patients with the same risk factors.

This is one of the first studies to compare postoperative THA outcomes between matched ON vs non-ON patients, while also taking into consideration specific risk factors between the cohorts.