Lumbar interlaminar and transforaminal epidural injections are used in the treatment of lumbar radicular pain and other lumbar spinal pain syndromes. Complications from these procedures arise from needle placement and the administration of medication. Potential risks include infection, hematoma, intravascular injection of medication, direct nerve trauma, subdural injection of medication, air embolism, disc entry, urinary retention, radiation exposure, and hypersensitivity reactions. The objective of this article is to review the complications of lumbar interlaminar and transforaminal epidural injections and discuss the potential pitfalls related to these procedures. We performed a comprehensive literature review through a Medline search for relevant case reports, clinical trials, and review articles. Complications from lumbar epidural injections are extremely rare. Most if not all complications can be avoided by careful technique with accurate needle placement, sterile precautions, and a thorough understanding of the relevant anatomy and contrast patterns on fluoroscopic imaging.

The use of pulsed and low-dose fluoroscopy in addition to lead shielding; increasing distance from the radiation source; collimation; limited use of magnification, boost, or digital subtraction; and proficiency with interventional techniques should be used to reduce radiation exposure in concordance with the principle of "as low as reasonably achievable."

A Morel-Lavallée lesion (MLL) is a posttraumatic soft-tissue injury characterized by an accumulation of blood, lymph, and other physiologic breakdown products between subcutaneous tissue and underlying fascia. It was first described as occurring over the proximal lateral thigh, but it has since been documented at various anatomic locations. Diagnosis is typically made by careful physical examination and a radiographic analysis, most commonly with magnetic resonance imaging (MRI). Recently, musculoskeletal ultrasound (US) has been recognized as a useful adjunct to and potential replacement for MRI in the diagnosis and monitoring of an MLL. We present a case report of a patient with an MLL of the knee. We obtained magenetic resonance (MRI) and US images at the time of diagnosis, and follow-up US images during convalescence. By doing so, we were able to identify several key sonographic findings of an MLL at this location and compare them with MRI. Although there have been several published reports to date that describe the use of musculoskeletal US in the diagnosis of MLL, this is the first of which we are aware that does so at the knee.

Continuing antiplatelet and anticoagulant medications for intermediate- to low-risk interventional spine procedures may be advisable. The MSAAA table may be a reasonable guideline reference for managing antiplatelet and anticoagulant drugs.