Reoperation Rates for Symptomatic Nonunions in Anterior Cervical Fusions From a National Spine Registry.

STUDY DESIGN: A retrospective cohort study with chart review. OBJECTIVE: To determine the reoperation rates for symptomatic nonunions for 1-level, 2-level, and 3-level anterior cervical discectomies and fusions (ACDFs) from a national spine registry. SUMMARY OF BACKGROUND DATA: There is very little data reported in the literature on reoperation rates for symptomatic nonunions after ACDFs. The reported nonunion rates are primarily based on radiographical evidence, although some of these may be asymptomatic. Similarly, there may be symptomatic patients with nonunions who elect not to have a reoperation. We think, however, data from a national spine registry provide a realistic and unbiased assessment of routine cervical spine fusion care and represent a heterogeneous population with varied indications and surgical techniques and are best suited to determine reoperations for symptomatic nonunions. METHODS: Using data from a Spine Implant Registry developed at a large integrated health care system (Kaiser Permanente), patients with ACDFs between January 2009 and December 2012 with 2-year follow-up were identified. Patient characteristics, admitting diagnosis, and number of levels fused were extracted from the registry. Reoperations for symptomatic nonunions from the index spinal procedure were identified by chart review. RESULTS: A cohort of 1054 patients with more than 2 years of follow-up were found to have reoperations for nonunions of 0.2%, 2.9%, and 6.5% for 1-level, 2-level, and 3-level ACDFs, respectively. CONCLUSION: A large cohort of ACDF patients with more than 2 years of follow-up had reoperations for nonunion rates significantly lower than reported in the literature for radiographical nonunions. We think our data add to the literature an important parameter (reoperations for nonunion rates) and provide useful information for patients, spine surgeons, and health care payers.

Risk Factors Associated With 30-day Readmissions After Instrumented Spine Surgery in 14,939 Patients: 30-day readmissions after instrumented spine surgery.

STUDY DESIGN: A retrospective review of instrumented spine registry from an integrated US healthcare system. OBJECTIVE: Investigate the 30-day readmission rate and risk factors after instrumented spine surgery. SUMMARY OF BACKGROUND DATA: Published readmission rates range from 2% to over 20%. We were interested in learning which patients were at greatest risk, when did readmissions occur, and why. METHOD: 30-day readmission rates were determined for 14,939 patients after an index spine procedure between 1/2009 and 3/2013. Data were analyzed with descriptive statistics, univariate, and multivariate logistic regression analysis. RESULT: The average age of the cohort was 59 (SD = 13.4) and 52% were female. The 30-day readmission rate was 5.5% (821/14,939). The temporal pattern for readmission was: 17% (140) at week 1, 48% (394) at week 2, 72% (591) at week 3, and 100% (821) at week 4. The leading causes were wound complications (infection, hematoma, dehiscence, seroma), sepsis, pain management, pneumonia, and pulmonary emboli/deep venous thrombosis. In a multivariate model, readmission risk factors were: malignancy (OR 2.99, 95% CI: 1.56, 5.73), operative time more than 400 minutes (OR 2.59, 95% CI: 1.66, 4.02), operative time 300-399 minutes (OR 2.33, 95% CI: 1.54-3.52), hospital stay 6-10 days (OR 2.03, 95% CI: 1.31-3.14), hospital stay more than 10 days (OR 1.85, 95% CI: 1.1, -3.08), surgical complications (OR 1.67, 95% CI: 1.18, 2.36), operative time 200-299 (OR 1.52, 95% CI: 1.04, 2.22), depression (OR 1.48, 95% CI: 1.14, 1.93), rheumatoid arthritis (OR 1.45, 95% CI: 1.05, 2.01), deficiency anemia (OR 1.30, 95% CI: 1.05, 1.61), and hypothyroidism (OR 1.29, 95% CI: 1.01, 1.64). CONCLUSION: Surgical complications (dural tear, deep infections, superficial infections, epidural hematoma), malignancy, lengthy operative times, and lengthy initial hospitalizations are all risk factors for 30-day readmission. These findings should be considered during preoperative assessment and surgical planning. LEVEL OF EVIDENCE: 3.