Cubital Tunnel Syndrome:

From: www.wheelessonline.com

- See: Nerve Entrapment

- Discussion:
     - cubital tunnel serves as major contraint for the ulnar nerve as it passes behind elbow;
     - the syndrome occurs most commonly between 30 to 60 years, and is exceptionally uncommon in children under 15 years;
     - inciting events:
           - symptoms may appear several years after trauma (hence tardy ulnar palsy)
           - common injures: fx of medial epicondyle, supracondylar fx w/ cubitus valgus deformity,
                  exuberant callus, or dislocation of the elbow;
           - also consider prior iatrogenic injury from intraoperative positioning;
     - effects of elbow flexion:
     - neural anatomy:
           - the internal anatomy of the ulnar nerve can partially explain the predominace of hand symptoms from in cubital tunnel syndrome;
           - nerve fibers to the FCU and FDP are located centrally, where as sensory fibers and nerve fibers to the hand intrinsics are located peripherally;
                  - generally, the peripheral nerve fibers are more sensitive to external compression, and this may explain
                          why the hand intrinsics are often more involved than the FCU and FDP;
     - ulnar neuropathy following head injury;
           - some form of ulnar neuropathy is common in pts w/ brain injury;
           - one of the main causes is heterotopic ossification;
           - it usually occurs w/ a spacit extremity;
           - because of spacitity and lack of fine motor control, combined w/ the patients inability
                  to complain, atrophy of the intrinsic musculature is the first sign of detection;
     - differential diagnosis: 
     - concomitant disorders:
           - thoracic outlet syndrome may occur in upto 1/3 patients;
           - carpal tunnel syndrome may occur in upto 40% of patients;
     - anatomy & sites of nerve compression 

- Clinical Findings:

- EMG in Cubital Tunnel Syndrome:

- Radiographs:
     - look for osteophytes and associated DJD which may occur frequently w/ cubital tunnel syndrome;

- Non Operative Treatment:
     - sleeping w/ the elbow flexed will worsen symptoms;
     - consists mainly of exension splinting at night or wearing a soft (sheep skin) elbow pad;
     - splints should hold arm in 70 deg of flexion;
     - vitamin B6 50 mg PO tid: some patients will note substantial relief w/ vit B6;
     - w/ good compliance 50% of patients can avoid surgery;
     - avoidance of repetitive elbow flexion and pronation, and avoidance of vibrating tools;
     - NSAIDS
     - references: 
            - Treatment of ulnar nerve palsy at the elbow with a night splint.

- Surgical Treatment:
     - indications:
            - many surgeons will refuse to operate for sensory changes alone;
            - surgical procedure is reserved for those with disability & weakness;
            - if weakness is early and mild, esp if Tinel's sign is present or EMG suggests cubital tunnel syndrome,
                    simple release is performed;
            - if associated DJD of the elbow is present, then consider debridement arthroplasty (see lateral approach);
            - as noted by Seradge et al 1998, w/ resistant symptoms, prolonging nonoperative treatment does not reduce
                    the cost of care and does not positively influence outcome;
                    - as noted by Kaempffe et al 1998, those w/ the most severe nerve entrapment (intrinsic atrophy or
                            abnormal EMG) tend to have worse surgical outcomes;
            - note that concomitant nerve compression syndromes may be associated w/ a higher rate of recurrence;
     - preoperative considerations:
            - if the patient believes that their CTS syndrome is work related, then he/she should work this out ahead of time;
            - be clear with the patient ahead of time, regarding the goals of surgery;
                   - if the patient tends to over-react to painful stimuli, then they will probably react the same following surgery;
                   - in patients at risk for poor outcome or delayed return to work (such as workers compensation), consider 10 days
                            of aggressive nonoperative therapy inorder to assess their subjective response to treatment;
                   - for instance, consider combining oral steroids, casting w/ elbow in 45 deg flexion (to ensure compliance), and cessation
                            of repetitive activity for 10 days;
                            - if the patient insists that no relief has been obtained, then the subjective results of surgery may be in doubt;
     - surgical technique options: (anatomy & sites of nerve compression) 
            - Isolated Division of the Aponeurosis:
            - Medial Epiondylectomy:
            - Subcutaneous Anterior Transposition:
            - Submuscular Anterior Transposition;
     - complications:
            - recurrent nerve compression:
                   - in the report by Caputo and Watson, the authors identified 20 patients w/ recurrent compression who underwent 
                           anterior subcutaneous transposition of the ulnar nerve;
                   - most common sites of compression were the medial intermuscular septum and the flexor-pronator aponeurosis;
                   - 15 patients had a good or excellent outcome; 5 patients had a fair or poor outcome;
                   - relief of pain and paresthesias were the most consistent favorable results;
                   - ref: Subcutaneous anterior transposition of the ulnar nerve for failed decompression of cubital tunnel syndrome.
                               Andrew E. Caputo and H. Kirk Watson. J Hand Surg 2000;25A:544-551