Faculty Bibliography

BACKGROUND/UNASSIGNED:The purpose of this study was to evaluate the association between timing of nerve repair and the ability to perform a primary nerve repair versus a bridge repair requiring the use of allograft, autograft, or a conduit in lacerated upper extremity peripheral nerve injuries. METHODS/UNASSIGNED:This is a retrospective case-control study of patients who underwent upper extremity nerve repair for lacerated peripheral nerves identified by Current Procedural Terminology codes. Timing of injury and surgery, as well as other information such as demographic information, mechanism of injury, site of injury, and type of nerve repair, was recorded. The odds of a patient requiring bridge repair based on the duration of time between injury and surgery was evaluated using logistic regression. RESULTS/UNASSIGNED:A total of 403 nerves in 335 patients (mean age 35.87 ± 15.33 years) were included. In all, 241 nerves were primarily repaired and 162 required bridge repair. Patients requiring bridge repair had a greater duration between injury and surgery compared with patients who underwent primary repair. Furthermore, the nerves requiring bridge repair were associated with a greater gap compared with the nerves repaired primarily. Based on logistic regression, each 1-day increase in duration between injury and surgery was associated with a 3% increase in the odds of requiring bridge repair. CONCLUSIONS/UNASSIGNED:There is no defined critical window to achieve a primary nerve repair following injury. This study demonstrated that nerve injuries requiring bridge repair were associated with a significantly greater delay to surgery.

The goal of this study was to define safe zones to prevent radial nerve injury in an extended deltopectoral approach. Relative distances of the upper margin (UMRN) and lower margin (LMRN) of the radial nerve to the proximal and distal borders of the pectoralis major and deltoid insertions were measured in 20 cadaveric arms. Four proximal humeral zones were identified (zone I, proximal border of the pectoralis major tendon to the proximal border of the deltoid tendon; zone II, proximal border of the deltoid tendon to the distal border of the pectoralis major tendon; zone III, distal border of the pectoralis major tendon to the distal border of the deltoid tendon; and zone IV, distal to the distal border of the deltoid tendon). On fluoroscopic measurement, mean distances between the UMRN and the proximal border of the pectoralis major tendon and the proximal border of the deltoid tendon were 71.6±2.1 mm and 26.2±2.5 mm, respectively. The incidence of the radial nerve in the spiral groove within each defined zone was as follows: zone I, 0%; zone II, 50%; zones III and IV, 100%. There was a significant association between anatomic zone and radial nerve entry into the spiral groove, χ²(3, N=88)=64.53, P<.001. The proximal border of the pectoralis major tendon to the proximal border of the deltoid tendon (zone I) is a safe location to avoid injury to the radial nerve. We recommend placing cerclage wires proximal to zone I from lateral to medial to avoid entrapment of the radial nerve. [Orthopedics. 2023;46(1):e31-e37.].

The objective of this study was to determine the role of ad- junctive surgical procedures on the median nerve for carpal tunnel syndrome as measured by somatosensory evoked potentials (SEPs) on the nerve. Fifty-five median nerves in 47 patients were studied. In each patient, a base-line SEP was recorded in the operating room prior to incision and then intraoperatively following each of three sequential pro- cedures: division of the transverse carpal ligament, an epi- neurolysis of the nerve, and finally, either an epineurotomy or epineurectomy that we refer to as a "limited internal neu- rolysis" since it did not involve any intraneural dissection of fascicles. Comparison of the baseline mean SEP latency for the median nerve, referred to as N19 (negative polarity = 19 msec), showed a statistically significant improvement following each of the three procedures. The average reduc- tion of latency after ligament release alone was 1.52 msec, and the total improvement in latency from baseline through limited internal neurolysis was 4.72 msec. Our study showed that epineurolysis followed by a limited internal neurolysis using either an epineurotomy or epineurectomy produced a significant electrophysiologic improvement in the median nerve. There was no significant difference when comparing epineurotomy and epineurectomy.

PURPOSE/OBJECTIVE:The extensor retinaculum of the wrist, a thickening of the deep forearm fascia, is often used as do- nor graft material for annular pulley reconstructions and bone-retinaculum-bone grafts for ligament reconstructions. The purpose of our study was to identify the relationships between the radial and ulnar styloids, readily recogniz- able topographic landmarks of the wrist, and the anatomic boundaries of the retinaculum. METHODS:The extensor retinacula of 12 preserved, right cadaver wrists (3 male and 9 female) were studied by gross dissection using 3.5-power loupe magnification. The proxi- mal and distal extents of the retinaculum were identified and marked with needles, and their distances from the radial and ulnar styloids measured to determine the lengths of the retinaculum on both sides. RESULTS:The extensor retinaculum on the radial side extended 23.9 ± 2.9 mm proximal to the radial styloid and 5.8 ± 2.6 mm distal to the styloid for a total length of 29.7 ± 3.8 mm. On the ulnar side, the retinaculum extended 2.4 ± 1.4 mm proximal to the ulnar styloid and 17.9 ± 2.6 mm distal to the styloid for a total length of 20.3 ± 2.9 mm. CONCLUSIONS:The extensor retinaculum has a consis- tent relationship with the readily recognized topographic landmarks of the radial and ulnar styloids. The use of the extensor retinaculum as donor material for pulley and liga- ment reconstruction make these findings useful for surgical planning.

BACKGROUND/UNASSIGNED:Much has been written about the diagnosis and treatment of soft tissue mallet injuries. However, there has been little regarding the characteristics of this injury affecting patients' prognosis. The purpose of this prospective study was to identify factors influencing the outcome of treatment of soft tissue mallet injuries. METHODS/UNASSIGNED:12 months. RESULTS/UNASSIGNED:15°. Those failing splint treatment were older compared with those successfully treated. Patient compliance was significantly associated with a successful outcome. Factors that did not significantly affect success included time to treatment, initial injury severity, splinting duration, sex, and ligamentous laxity. Disabilities of Arm, Shoulder, and Hand scores >0 were not associated with treatment failure. Radiographic and clinical extension lag were statistically comparable. CONCLUSIONS/UNASSIGNED:This study shows strong association between the success of splint treatment, younger patient age, and compliance with the treatment protocol. Despite this finding, most patients did not report any functional limitations, irrespective of the treatment success. In contrast to prior results, time to treatment and initial extensor lag did not significantly affect treatment success.

Neuropathic symptoms involving the wrist are a common clinical presentation that can be due to a variety of causes. Imaging plays a key role in differentiating distal nerve lesions in the wrist from more proximal nerve abnormalities such as a cervical radiculopathy or brachial plexopathy. Imaging complements electrodiagnostic testing by helping define the specific lesion site and by providing anatomical information to guide surgical planning. This article reviews nerve anatomy, normal and abnormal findings on ultrasonography and magnetic resonance imaging, and common and uncommon causes of neuropathy.