Axillary Nerve Monitoring During Arthroscopic Shoulder Stabilization
This study evaluated the ability of a novel intraoperative neurophysiologic monitoring method used to locate the axillary nerve, predict relative capsule thickness, and identify impending injury to the axillary nerve during arthroscopic thermal capsulorrhaphy of the shoulder.
Prospective cohort study.
Twenty consecutive patients with glenohumeral instability were monitored prospectively during arthroscopic shoulder surgery. Axillary nerve mapping and relative capsule thickness estimates were recorded before the stabilization portion of the procedure. During labral repair and/or thermal capsulorrhaphy, continuous and spontaneous electromyography recorded nerve activity. In addition, trans-spinal motor-evoked potentials of the fourth and fifth cervical roots and brachial plexus electrical stimulation, provided real-time information about nerve integrity.
Axillary nerve mapping and relative capsule thickness were recorded in all patients. Continuous axillary nerve monitoring was successfully performed in all patients. Eleven of the 20 patients underwent thermal capsulorrhaphy alone or in combination with arthroscopic labral repair. Nine patients underwent arthroscopic labral repair alone. In 4 of the 11 patients who underwent thermal capsulorrhaphy, excessive spontaneous neurotonic electromyographic activity was noted, thereby altering the pattern of heat application by the surgeon. In 1 of these 4 patients, a small increase in the motor latency was noted after the procedure but no clinical deficit was observed. There were no neuromonitoring or clinical neurologic changes observed in the labral repair group without thermal application. At last follow-up, no patient in either group had any clinical evidence of nerve injury or complications from neurophysiologic monitoring.
We successfully evaluated the use of intraoperative nerve monitoring to identify axillary nerve position, capsule thickness, and provide real-time identification of impending nerve injury and function during shoulder thermal capsulorrhaphy. The use of intraoperative nerve monitoring altered the heat application technique in 4 of 11 patients and may have prevented nerve injury.
Level II, prospective cohort study.
Available from: Tetsunari Inamura
[Show abstract] [Hide abstract]
ABSTRACT: In this paper, we focused on concepts of behavior modifier. We aim to build a system, which acquires concepts of behavior modifier and applies it to motion generation of robots. For a form of motion representation, an existing research achievement, which statistically abstracts motion with known sets of motion examples and represents motions as points in a space, was adopted. Our system uses tendency of motions with adverbial modifier in the space to represent concepts of behavior modifier. The system has a simple representation form and has interactiveness what has potential advantage of ability to be applied to various motion concepts.
[Show abstract] [Hide abstract]
ABSTRACT: The incidence of neurologic injury after shoulder arthroplasty has been reported to be 1% to 4%. However, the true incidence may be higher, because injury is identified only clinically and examination of the post-arthroplasty shoulder is difficult. This study used intraoperative nerve monitoring to identify the incidence, pattern, and predisposing factors for nerve injury during shoulder arthroplasty. Continuous intraoperative monitoring of the brachial plexus was performed in 30 consecutive patients undergoing shoulder arthroplasty. Impending intraoperative compromise of nerve function was signaled by sustained neurotonic electromyographic activity or greater than 50% amplitude attenuation of transcranial electrical motor evoked potentials (or both). Arm and retractor positions were recorded and adjusted to relieve tension. Patients with intraoperative nerve alerts underwent diagnostic electromyography at least 4 weeks postoperatively. Of the patients, 17 (56.7%) had 30 episodes of nerve dysfunction (ie, nerve alerts) during surgery. None of these 30 nerve alerts returned to baseline with retractor removal alone. Of the 30 alerts, 23 (76.7%) returned to baseline after repositioning of the arm into a neutral position. Postoperative electromyography results were positive in 4 of 7 patients (57.1%) who did not have a return to baseline transcranial electrical MEPs intraoperatively and in 1 of 10 (10%) whose nerve function did return to baseline. In all cases of positive postoperative electromyographic results, the pattern of nerve involvement matched the pattern of intraoperative nerve dysfunction. The affected nerves included the following: combined (ie, mixed plexopathy) (46.7%), musculocutaneous (20%), axillary (16.7%), ulnar (10%), and radial (6.7%). Prior shoulder surgery and passive external rotation of less than 10 degrees were associated with an increased incidence of nerve dysfunction (P < .05). The incidence of nerve injury during shoulder arthroplasty is likely greater than reported. Positioning of the arm at the extremes of motion should be minimized. Patients with decreased motion (<10 degrees passive external rotation with the arm at the side) and a history of prior open shoulder surgery are at higher risk for nerve injury and should be counseled on the increased risk. This patient population may also be considered for routine nerve monitoring.
[Show abstract] [Hide abstract]
ABSTRACT: This chapter reviews that intraoperative electrophysiology has become an important neurological extension to surgeons. It provides vital information to guide intraoperative decisions about the type of neural reconstruction to perform, to localize the site of injury, and to avoid unnecessary injury to the nerve during procedures directly involving or nearby nerve. It allows surgeons to assess, predict, and preserve nerve function, thereby improving operative outcomes. The chapter discusses that intraoperative electrophysiology is valuable during operations related to the peripheral nerve injury, nerve entrapment, tumor biopsy or resection, and other reconstruction. In these situations, it is particularly useful to assess neuromas in continuity, to evaluate the site and degree of compression during nerve decompression, to prevent injury to the affected or neighboring nerves during tumor resection, or to minimize neural complications from fascicular biopsy; fascicular nerve transfer or during “high-risk” procedures around nerve. The chapter concludes that intraoperative electrophysiological testing should not be considered as a replacement but rather as a complement to preoperative clinical, electrophysiological, and imaging evaluations and a thorough intraoperative morphological examination.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.