Anatomical Factors Contributing to Radial Nerve Excursion at the Brachium: A Cadaveric Study.

PURPOSE: The radial nerve appears to be more vulnerable to injury in the brachium than the median and ulnar nerves. The underlying mechanism for this increased vulnerability is not well explained. We hypothesize that the radial nerve has less excursion than the median and ulnar nerves because it is anatomically tethered by the lateral intermuscular septum (LIS) and that elbow positioning and LIS release will improve its excursion. METHODS: Eight paired fresh-frozen cadaveric upper extremity specimens were used. The radial, median, and ulnar nerves were transected at the level of the spiral groove. Nerve excursion was determined at a constant tension of 100 g from 0° to 90° of elbow flexion and repeated for the radial nerve after releasing the LIS. The cross-sectional areas of nervous and connective tissue were then determined histologically. RESULTS: Radial and median nerve excursion correlated positively with increased elbow flexion, and ulnar nerve excursion correlated negatively with increased elbow flexion. Release of the LIS significantly improved radial nerve excursion at 0°, 60°, and 90° of elbow flexion. Release of the LIS with 90° of elbow flexion increased radial nerve excursion by approximately 3 times. Histological analysis demonstrated similar mean composition of nonnervous connective tissue among the 3 nerves. CONCLUSIONS: The radial nerve is anatomically tethered in the brachium by the LIS and has limited excursion compared with the median and ulnar nerves. Radial nerve excursion improves with elbow flexion and LIS release. Flexing the elbow to 90° doubles radial nerve excursion. Releasing the LIS as well triples the excursion of the radial nerve. Histological composition was similar among the three nerves at the brachium. CLINICAL RELEVANCE: Releasing the LIS and flexing the elbow improve radial nerve excursion. These steps may be useful during humeral fracture fixation.

Disseminated Cryptococcal Osteomyelitis to the Hand in an Immunosuppressed Lymphoma Patient.

Fungal osteomyelitis of the hand is rare with limited evidence-based literature to guide diagnosis and management. We report a case of disseminated cryptococcal osteomyelitis in the middle phalanx from a pulmonary fungal infection in a patient with a history of lymphoplasmacytic lymphoma. Although rare, cryptococcosis should be considered in the differential diagnosis of aggressive lytic lesions with bone pain and associated large soft tissue masses, especially in the immunosuppressed host.

Transfer of the Dorsal Cutaneous Branch of the Ulnar Nerve for Restoration of Median Nerve Sensation: A Cadaveric Study.

The use of dorsal cutaneous branch of the ulnar nerve (DCBUN) transfer for median nerve (MN) sensory restoration has not been evaluated anatomically and histologically in humans. The purpose of this study was to evaluate the feasibility of DCBUN to MN transfer for sensory restoration with respect to nerve branch pattern, length, and fascicle count match.Using seven fresh frozen cadaveric upper limb specimens, the DCBUN and its branch patterns, lengths, and sizes were recorded. The MN was exposed within the carpal tunnel and dissected distally to identify the common digital nerves (CDN). Simulated nerve transfer was performed with palmar coaptation of the DCBUN branches with the CDNs. Histological analysis of each nerve branch was performed. The seven specimens had a mean of 3.57 branches (range 2-4) off the DCBUN. The longest branch innervated the dorsal 4th web space, on average reaching 7.6 cm distal to the wrist crease. Transferring the DCBUN branches palmarly did not substantially change their maximum distance distal to the wrist crease. The MN CDNs and DCBUN branches had mean cross-sectional areas of 6.37 and 1.99 mm2 , respectively, and mean fascicle counts of 10.4 and 4.05, respectively. The DCBUN provides 2-4 branches suitable for tension-free end-to-end transfer to the MN CDNs. The individual size of the DCBUN branch is smaller than CDN; however, combining two or more branches of the DCBUN would overcome the fascicle and size mismatch to reconstruct the 1st web space CDN for critical sensory restoration. Clin. Anat. 31:1006-1012, 2018. © 2018 Wiley Periodicals, Inc.

Marginal Skin Flap Advancement: A Technique to Optimize the Skin Graft Interface Following Tumor Resections.

Split-thickness skin graft (STSG) for soft tissue defects is often required following tumor resections. There is often a step-off with subcutaneous adipose tissue along the defect margins. This review of 20 years of experience was performed to determine the success of marginal skin flap advancement, a simple surgical technique addressing this issue. Seventy-one cases were identified that underwent sarcoma resection and this technique. Marginal skin flap advancement decreased the defect size from 217 s 162 cm2 to 128 s 101 cm2 (p < .001). STSG was successfully applied in 69 cases (97%) with a mean 96% take of the skin graft. Although 29 cases (41%) had wound healing complications of any nature, only 11 (15%) required a secondary operation. Marginal skin flap advancement, in conjunction with vacuum-assisted closure therapy, decreases the defect surface area requiring STSG by 41% and provides an excellent reconstructive option for soft tissue defects following sarcoma resections. (Journal of Surgical Orthopaedic Advances 27(2):102-108, 2018).

Surgical Algorithm and Results of Isolated Traumatic Axillary Nerve Injuries.

BACKGROUND: Axillary nerve injuries are common and typically occur during high-energy, traumatic events. The purpose of this study is to propose a treatment algorithm for acute isolated axillary nerve injuries and report the outcomes of surgically treated patients. METHODS: A retrospective review identified 14 patients surgically treated for an isolated axillary nerve injury. Axillary nerve neurolysis was performed for all patients, and a triceps branch of the radial nerve was transferred to the axillary nerve in patients without evidence of deltoid function following intraoperative axillary nerve stimulation. Four patients were treated with neurolysis alone and 10 patients received a transfer. Pre- and postoperative deltoid strength, shoulder abduction, and the Disabilities of the Arm, Shoulder, and Hand (DASH) outcome score were evaluated. RESULTS: At most recent follow-up, both the neurolysis and nerve transfer groups had significant improvement in deltoid strength, with 86% achieving M4 or greater. Shoulder abduction improved from a mean of 63 to 127 degrees. This difference was significant in the nerve transfer group and when all patients were analyzed together. DASH scores significantly improved from a mean of 47 to 34 when all patients were analyzed together. No patients experienced a decrease in elbow extension strength following nerve transfer. CONCLUSIONS: In patients with preserved triceps strength, a triceps branch of the radial nerve can be coapted directly to the axillary nerve in the absence of deltoid contraction following electrical stimulation. Functional improvements were seen in patients treated with neurolysis alone and in combination with nerve transfer, supporting the use of intraoperative axillary nerve stimulation to guide treatment.

Effect of setting of initial surgical drainage on outcome of finger infections.

This study sought to determine the optimal treatment setting (emergency department vs. operating room) for the initial incision and drainage of acute suppurative finger infections. A search of hospital medical records over a 5-year period identified 152 cases. In 108 cases (71%), a single drainage successfully resolved infection; 44 cases (29%) required multiple drainage procedures. Treatment setting did not decrease the risk for multiple procedures. Seventy-six cases (57%) of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) were identified. Bivariate analysis identified CA-MRSA infection as a significant, independent risk factor for multiple procedures. Obtaining initial cultures correlated with a decreased need for multiple procedures. In conclusion, initial surgical drainage in the emergency department is a safe alternative to the operating room. However, patients with CA-MRSA infection have an increased risk for persistent infection requiring multiple procedures. Prompt organism identification and appropriate antibiotics following surgical drainage remain most crucial for the successful treatment of finger infections.

Arthroscopic treatment of an osteochondral lesion in a child with chronic wrist pain: case report.

Osteochondral lesions of the wrist are rare in the pediatric and adolescent population. We report a case of an osteochondral lesion of the lunate facet of the radiocarpal joint in a 6-year-old girl with chronic wrist pain after falling on her hand. Arthroscopic debridement of the osteochondral fragment relieved the symptoms and improved wrist function. Osteochondral lesions should be considered in the differential diagnosis of chronic wrist pain in children with a history of trauma.

An ulnar intraneural ganglion arising from the pisotriquetral joint: case report.

Intraneural ganglions of the hand are rare and remain poorly understood. We report a case of an intraneural ganglion arising from the pisotriquetral joint that penetrated the ulnar nerve at Guyon's canal. Although rare, these ganglions should be considered in the differential diagnosis of any neoplasms causing compression neuropathy.

Age-Dependent Schwann Cell Phenotype Regulation Following Peripheral Nerve Injury.

BACKGROUND: Schwann cells are integral to the regenerative capacity of the peripheral nervous system, which declines after adolescence. The mechanisms underlying this decline are poorly understood. This study sought to compare the protein expression of Notch, c-Jun, and Krox-20 after nerve crush injury in adolescent and young adult rats. We hypothesized that these Schwann cell myelinating regulatory factors are down-regulated after nerve injury in an age-dependent fashion. METHODS: Adolescent (2 months old) and young adult (12 months old) rats (n = 48) underwent sciatic nerve crush injury. Protein expression of Notch, c-Jun, and Krox-20 was quantified by Western blot analysis at 1, 3, and 7 days post-injury. Functional recovery was assessed in a separate group of animals (n = 8) by gait analysis (sciatic functional index) and electromyography (compound motor action potential) over an 8-week post-injury period. RESULTS: Young adult rats demonstrated a trend of delayed onset of the dedifferentiating regulatory factors, Notch and c-Jun, corresponding to the delayed functional recovery observed in young adult rats compared to adolescent rats. Compound motor action potential area was significantly greater in adolescent rats relative to young adult rats, while amplitude and velocity trended toward statistical significance. CONCLUSIONS: The process of Schwann cell dedifferentiation following peripheral nerve injury shows different trends with age. These trends of delayed onset of key regulatory factors responsible for Schwann cell myelination may be one of many possible factors mediating the significant differences in functional recovery between adolescent and young adult rats following peripheral nerve injury.

Needle Curette Technique for Hand Surgery.

Curettage of lesions in the hand often requires fine instruments of varying angles for a thorough debridement. This can be seen with debridement of enchondromas of the phalanges when minimizing the size of the cortical window is desired. In this technical note, the authors describe the modification of an 18-G needle so that it may be used as a small curette when standard small curettes are not available or optimal.