Axillary nerve monitoring during arthroscopic shoulder stabilization.
ABSTRACT 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.
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ABSTRACT: Thermal capsular shrinkage was popular for the treatment of shoulder instability, despite a paucity of outcomes data in the literature defining the indications for this procedure or supporting its long-term efficacy. The purpose of this study was to perform a clinical evaluation of radiofrequency thermal capsular shrinkage for the treatment of shoulder instability, with a minimum 2-year follow-up. From 1999 to 2001, 101 consecutive patients with mild to moderate shoulder instability underwent shoulder stabilization surgery with thermal capsular shrinkage using a monopolar radiofrequency device. Follow-up included a subjective outcome questionnaire, discussion of pain, instability, and activity level. Mean follow-up was 3.3 years (range 2.0-4.7 years). The thermal capsular shrinkage procedure failed due to instability and/or pain in 31% of shoulders at a mean time of 39 months. In patients with unidirectional anterior instability and those with concomitant labral repair, the procedure proved effective. Patients with multidirectional instability had moderate success. In contrast, four of five patients with isolated posterior instability failed. Thermal capsular shrinkage has been advocated for the treatment of shoulder instability, particularly mild to moderate capsular laxity. The ease of the procedure makes it attractive. However, our retrospective review revealed an overall failure rate of 31% in 80 patients with 2-year minimum follow-up. This mid- to long-term cohort study adds to the literature lacking support for thermal capsulorrhaphy in general, particularly posterior instability. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11420-010-9187-7) contains supplementary material, which is available to authorized users.HSS Journal 07/2011; 7(2):108-14.
- The Journal of Urology 04/2011; 185(4). · 3.75 Impact Factor
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ABSTRACT: Reports place the frequency of axillary nerve injury at 6% for all brachial plexus injuries, emphasizing the importance of an accurate anatomic description of this nerve within the deltoid in order to reduce iatrogenic injury. The aim of the present study was to explore the anatomic variations of the axillary nerve within the deltoid muscle. Fifty human cadavers were dissected, resulting in 100 nerve specimens. The anterior and posterior branches of the axillary nerve were identified and their length measured from their point of origin (split from the axillary nerve) to their termination in the deltoid muscle. In 65% of cases, the axillary nerve split into two branches (anterior and posterior) within the quadrangular space, and in the remaining 35% split within the deltoid muscle. The posterior branch of the deltoid muscle irrespectively of origin gave off a branch to the teres minor and the superior lateral brachial cutaneous nerve in 100% of cases. The branch to the posterior part of the deltoid muscle was present in 90% of cases, and the branch to the middle part of the deltoid was present in 38% of cases. The anterior branch of the deltoid muscle provided a branch to the joint capsule, a branch to the anterior part of the deltoid muscle and the middle part of the deltoid in 100% of cases. In 18% of the cases, the anterior branch of the axillary nerve provided a branch to the posterior part of the deltoid muscle. The middle part of the deltoid muscle received dual innervation in 38% of cases and the posterior part of the deltoid muscle in 8% of the cases.Surgical and Radiologic Anatomy 01/2009; 31(1):43-47. · 1.13 Impact Factor