Musculoskeletal 5

What is the DDx and procedural management for a worker with LBP and leg pain in which conservative treatment has failed?
• Rule out systemic disease: cancer, rheum
• DDx: lumbar disc herniation, SI joint pain, facet pain, diskogenic pain, piriformis syndrome, spondylolisthesis, lumbosacral plexopathy, and lumbar spinal stenosis
• Facet pain: makes up 15-40% LBP patients. Intraarticular facet blocks can be therapeutic and diagnostic. For pure diagnosis, can do an anesthic block of the medial branches of the dorsal rami. If beneficial, can consider radiofrequency ablation.
• SI joint pain: 18-30% chronic LBP. Intraarticular SI joint steroid injections are controversial.
• ESI not proven well by studies
What are the biomechanical changes and treatment recommendations for a 40 year old dockworker diagnosed with lumbar disk herniation?
• Natural history favorable for spontaneous improvement
• At 10 year follow up, surgical group did similar to conservative group
• Caudal and intralaminar injections provide easy access to epidural space, although studies show 1/3 of blind injections do not access epidural space
• Transforaminal ESI delivers meds to anterior epidural space where nerve root traverse, always done with fluoro, may help patients reduce pain and avoid surgery

What is the efficacy of interventional procedures in diagnosis and treatment of posterior element pain in a patient with predominant LBP?
• Posterior elements: facet joints, SI joints
• Criteria that increase likelihood of facet pain: age > 65, pain relieved with recumbency, no pain exacerbation with coughing, sneezing, forward flexion, hyperextension.
• Facet pain may refer to lower back and hip
• Medial branch blocks can be diagnostic and therapeutic
• Intraarticular facet injections have been validated as an effective treatment, but limited long term efficacy
• Radiofrequency ablation of the medial branch effective in 85% of patients who responded to anesthetic block --> nerve regenerates in 90 days, no associated weakness
• SI joint: true joint with 2-3 ml of synovial fluid --> pain from trauma, sheer forces, ankylosing spondylitis, pregnancy, idiopathic
• Pain maps of SI joint intersect with facet and radic pain
• Intraartic injection of steroid and anesthetic is common treatment --> can get relief up to a year

What further diagnosis and treatment should be done on a 40 year old with disk degeneration, LBP, and referred leg pain if conservative management has failed?
• In pts with chronic LBP, prevalence of diskogenic pain is 40%
• High intensity zone on MRI within intervertebral disk may reflect annular tear, although also present in asymptomatic patients
• Diskography: performed at 3 levels in L-spine to provide at least 1 control. Procedure is painful and risks include nerve injury, diskitis, and epidural abscess --> may identify painful disk but limited value in predicting success in surgical fusion
• Intradiskal electrothermal annuloplasty: heating element catheter applied to annulus --> used on patients with axial pain and sitting intolerance >6 months with 50% preservation of disk height --> about 50% of patients have good relief, but mixed studies
• Percutaneous nucleoplasty: uses radiofrequency energy to break down molecular structures in the nucleus pulposus --> may cause disk to shrink --> not much literature to support
• Disk arthroplasty: completely replacement of disk --> new, little data