Background and Goal of Study: A feared complication of spinal or epidural anesthesia is the development of epi- or intradural hematomas with subsequent neural element compression. Most data available are derived form the obstetric literature. However, little is known on the frequency of its occurrence in the orthopedic joint arthroplasty population, which is usually elderly and suffers from significant comorbid burden. We sought to study the incidence of clinically significant lesions after spinal and epidural anesthesia and further describe their nature.
Materials and Methods: We analyzed charts of all patients who underwent THA or TKA under neuraxial anesthesia at our institution between January 2000 and October 2010. Patients with radiographically confirmed epidural lesions were identified and further analyzed.
Results and Discussion: A total of 100,027 total knee and hip replacements were performed at our institution utilizing either spinal (37,171) or a combination of spinal-epidural anaesthesia with indwelling catheter (62,856). 97 (0.098%) patients underwent imaging studies to evaluate perioperative neurologic deficits. A total of 8 (0.008% or 1:12,500) patients were identified with positive findings for an epidural blood or gas collection (4 female, 4 male, average age 71.6 years (±10), average body mass index 29.1 kg/m2 (±5.2 kg/ m2)). On average, the post-operative finding was radiographically diagnosed 3.1 days (±1.5) after surgery. No patients receiving spinal anesthesia only were affected. The International Normalized Ratio (INR) at the time of catheter removal was within normal range in all cases. The presenting complaint was unrelenting, non-positional acute onset back pain in five and major neurologic motor deficits in three patients; two required emergent surgical decompression. All patients diagnosed with hematoma took at least one drug that potentially impaired coagulation (five non-steroidal anti-inflammatory agents, one a selective serotonin reuptake inhibitors, and one an anti-platelet drug). No patient incurred persistent nerve damage.
Conclusion: The incidence of epidural/spinal complications found in this consecutive case series is relatively low, but higher than previously reported in the non-obstetric population1. Further research utilizing large datasets could quantify the significance of some of the potentially contributing factors observed in this study.
1. Horlocker et al. Br J Anaesth 2011 Dec