Management of Ulnar Nerve Compression Using Ulnar Transposition
Submuscular anterior transposition is the recommended surgical treatment for ulnar nerve compression at the elbow, particularly in patients with persistent symptoms after conservative management or those with ulnar nerve subluxation/luxation.
Diagnostic Approach
- MRI without IV contrast is the reference standard for imaging ulnar nerve entrapment, showing high signal intensity and nerve enlargement on T2-weighted images 1
- Ultrasound is an effective alternative with high accuracy (sensitivity 77-79%, specificity 94-98%) for assessing cross-sectional area and nerve thickness 1
- Shear-wave elastography has demonstrated 100% specificity and sensitivity for diagnosing ulnar neuropathy at the elbow 1
Conservative Management
- Initial treatment for acute and subacute ulnar neuropathy should be non-surgical, including rest and avoiding pressure on the nerve 2
- If symptoms persist, splint immobilization of the elbow and wrist is warranted 2
- Paracetamol (up to 4g/day) is recommended as first-line oral analgesic for pain management 1
- Topical NSAIDs are recommended for localized pain with fewer systemic side effects 1
- Range of motion and strengthening exercises help maintain function 1
Surgical Management
- For chronic neuropathy associated with muscle weakness or neuropathy that does not respond to conservative measures, surgery is usually necessary 2
- Three main surgical approaches for ulnar nerve transposition:
1. Submuscular Transposition
- Highest success rate for chronic neuropathies requiring surgery 2
- Preferred procedure when prior surgery has been unsuccessful 2
- Provides better outcomes in patients with habitual ulnar luxation or subluxation compared to simple decompression 3
- Approximately 73% objective improvement rate after submuscular transposition 3
2. Subcutaneous Transposition
- Less complicated procedure than submuscular transposition 2
- Particularly effective in elderly patients and those with thick adipose tissue in their arms 2
- Procedure of choice for repositioning the nerve during surgical reductions of acute fractures, elbow arthroplasties, and secondary neurorrhaphies 2
- Key surgical steps include thorough decompression along the entire course of the nerve, preserving the venous plexus, and resection of a 3-6 cm segment of the medial intramuscular septum 4
3. Intramuscular Transposition
- Can result in severe postoperative perineural scarring despite favorable reported outcomes 2
- Requires careful placement of the transposed nerve in an intramuscular bed with resection of all fibrous septae to avoid scar formation 5
- Postoperative immobilization for 3 weeks is typically recommended 5
Surgical Technique Considerations
- Regardless of transposition type, thorough decompression along the entire course of the nerve is essential 4
- Common sites of persistent ulnar nerve compression include the medial intermuscular septum, arcade of Struthers, fibrous bands proximal or distal to the cubital tunnel, and incomplete anterior transposition 5
- Proper positioning during surgery is critical to prevent additional nerve injury, with either supination or neutral forearm position recommended 6
- Excessive elbow flexion (>90°) should be avoided as it may increase risk of ulnar neuropathy 1
Postoperative Considerations
- Following intramuscular transposition, most patients can resume regular activities by 8 weeks postoperatively 5
- Ultrasound can be valuable in assessing the nerve in cases of persisting symptoms after transposition, potentially identifying issues such as nerve kinking at fascial passages 7
- Approximately 90% of patients report subjective improvement regardless of the surgical method used 3