Nerve Conduction Studies in Surgical Cubital Tunnel Syndrome Patients.

Background: Electrodiagnostic studies (EDX) serve a prominent role in the diagnostic workup of cubital tunnel syndrome (CBTS), but their reported sensitivity varies widely. The goals of our study were to determine the sensitivity of EDX in a cohort of patients who responded well to surgical cubital tunnel release (CBTR), and whether the implementation of the Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) criteria improves the sensitivity. Methods: We identified 118 elbows with clinical CBTS who had preoperative EDX and underwent CBTR. The EDX diagnoses were CBTS, ulnar neuropathy (UN), and normal ulnar nerves. We divided the 118 elbows into those that received above-elbow stimulation (XE group) and those that did not (non-XE group). We calculated the sensitivities for all groups and reinterpreted the results according to the AANEM guidelines. Results: Cubital tunnel release provided significant relief in 93.6% of the elbows. Based on the EDX reports, 11% patients had clear CBTS, 23% had UN, and 66% showed no UN. The sensitivities were 11.7% for CBTS and 34.2% for any UN. In the XE group, the sensitivity of the EDX reports for CBTS and UN climbed to 33.3% and 58.3%, respectively. When we calculated the across-elbow motor nerve conduction velocity, the sensitivity for CBTS and UN was 87.5% and 100%, respectively. The XE and non-XE groups showed no difference except for sex, bilaterality, concomitant carpal tunnel release, and obesity (P < .05). Conclusion: Implementing AANEM guidelines results in significant improvement in correlation of clinical and electrodiagnostic findings of CBTS.

Knot security: how many throws does it really take?

The purpose of this study was to determine the minimum number of throws needed for knot security for square knots using 5 common suture materials and 3 common sizes by in vitro single load to failure biomechanical testing. The hypothesis was that each suture combination studied would share a common minimum of at least 5 throws to guarantee security. Five suture materials (FiberWire [Arthrex, Inc, Naples, Florida], Monosof, Surgipro, Maxon, and Polysorb [Covidien, Mansfield, Massachusetts]) with varying suture sizes (#5, #2, 0, 2-0, and 4-0) were tied in vitro, varying the number of square knot throws (3, 4, 5, and 6). Twenty knots for each combination were statically loaded to failure in tension; whether the knot failed by fracture or slippage and the tensile strength at knot failure was determined. For the tested materials, at least 5 flat square throws should be used to confer knot security based on a binomial proportion score 95% confidence interval (CI) 0.84 to 1.0 or at least 4 throws for a 95% CI of 0.76 to 0.99. FiberWire requires 6 flat square throws per knot for security at either 95% CI level. Unless a surgeon has specific knowledge of experimental evidence that fewer throws are necessary for a specific application, the default should be a minimum of 4 throws, with 5 conferring additional security in most situations, and FiberWire requiring 6 throws.

Spontaneous bacterial seeding of a biceps hematoma.

A 19-year-old male construction worker presented with an injury to his left upper arm after lifting a heavy pipe. He reported an acute onset of sharp pain followed by swelling, warmth, and weakness with elbow flexion. The diagnosis of a distal biceps tendon rupture was made and elective repair was scheduled. Seventy-two hours later, the patient presented with a spontaneous draining wound on his anterior distal humerus. The wound was draining thick purulent material. The patient underwent surgery for irrigation and debridement of his abscess. Nearly 500 cc of hematoma and purulent fluid were evacuated. A large tear of both the biceps and brachialis muscle bellies were found. Cultures were obtained that revealed the infecting organism to be Streptococcus intermedius. Human immunodeficiency virus and hepatitis-C virus testing were negative, and no history, signs, or symptoms of any cause of underlying immunodeficiency were detected. No signs or history of drug use were present. He was discharged home on culture-specific oral antibiotics. At 4-month postoperative follow-up, the patient reported no pain or limitations. He has returned to full duty at his job. Elbow range of motion was measured from 7° to 150° of flexion. Strength of elbow flexion and extension was symmetric to the uninjured side. Pronation and supination of the forearm was symmetric on both sides. He has been released from scheduled follow-up and will be seen again on an as-needed basis.