Nerve Impingement at Elbow: Diagnosis and Management
Direct Answer
For adults with suspected ulnar nerve entrapment at the elbow (cubital tunnel syndrome), begin with dynamic ultrasound to visualize nerve subluxation, followed by 3-6 months of conservative management including activity modification, neutral positioning, and proper padding—unless motor weakness or muscle atrophy is present at initial evaluation, which warrants immediate surgical referral. 1, 2
Diagnostic Approach
Initial Imaging Strategy
- Dynamic ultrasound is the preferred first-line diagnostic test to directly visualize ulnar nerve subluxation during elbow flexion, with high accuracy for demonstrating nerve dislocation 1, 2
- MRI with T2-weighted neurography serves as the reference standard if ultrasound is inconclusive, showing nerve signal intensity and enlargement 1, 2
- Plain radiographs should be obtained initially to rule out osseous pathology, intra-articular bodies, osteochondral lesions, and occult fractures 3
Electrodiagnostic Confirmation
- Electromyography and nerve conduction studies help confirm the diagnosis in atypical presentations and differentiate between demyelinating versus axonal injury 1, 2
- These studies are particularly useful when neurologic symptoms suggest concurrent nerve pathology 3, 4
Clinical Presentation to Assess
- Numbness and tingling in the ring and little fingers (earliest sign) 5
- Weakness or atrophy of intrinsic hand muscles, particularly the first dorsal interosseous 6, 5
- Pain and point tenderness at the medial elbow 5
- Tinel's sign at the cubital tunnel and positive flexion-compression test 5
- Motor symptoms are more common in older patients; younger patients tend to have more acute sensory symptoms 5
Conservative Management Algorithm
Patient Selection for Conservative Treatment
Conservative treatment for 3-6 months is appropriate for patients WITHOUT significant motor weakness or muscle atrophy at presentation 1, 2
Positioning and Activity Modification
- Maintain neutral forearm position when the arm is at the side to minimize nerve tension 1, 2
- Avoid elbow flexion beyond 90° as this increases risk of nerve compression and subluxation 1, 2
- Modify activities that involve repetitive elbow flexion or direct pressure on the medial elbow 5
Protective Measures
- Apply proper padding (foam or gel pads) at the elbow to prevent compression 1, 2
- Critical pitfall: Ensure padding is not too tight, as this creates a tourniquet effect and paradoxically increases compression risk 1, 2
- Consider elbow splints or braces, particularly for nighttime use 5
Pain Management
- Paracetamol (up to 4g/day) as first-line oral analgesic 2
- Topical NSAIDs for localized pain with fewer systemic side effects 2
- Oral NSAIDs at lowest effective dose for shortest duration if inadequate response to paracetamol 2
- Cryotherapy (ice application) for 10-minute periods for acute pain relief 3
Therapeutic Exercises
- Range of motion and strengthening exercises to maintain function 2
- Nerve-gliding exercises 5
- Local heat application before exercise 2
Surgical Indications
Surgery is indicated in the following scenarios: 2
- Conservative treatment fails after 3-6 months
- Progressive motor weakness or muscle atrophy is present at initial evaluation
- Recurrent nerve subluxation/dislocation is documented on dynamic imaging
- Significant sensory deficits persist or worsen despite conservative management
Surgical Options
Multiple techniques are available including simple in situ decompression, decompression with medial epicondylectomy, anterior subcutaneous transposition, and anterior submuscular transposition 7, 8, 4
Critical Pitfalls to Avoid
- Do not use tight padding or braces—this creates a tourniquet effect and worsens compression 1, 2
- Do not allow elbow flexion greater than 90° during positioning or activities 1, 2
- Be aware that shoulder braces placed over the acromioclavicular joint may increase risk of brachial plexus neuropathy 1
- Consider concurrent median nerve compression at the wrist (carpal tunnel syndrome), which may occur simultaneously in certain metabolic conditions 1
- Do not delay surgical referral when motor weakness or muscle atrophy is present, as chronic compression can lead to irreversible damage affecting quality of life and fine motor function 5