Injury to the axillary and suprascapular nerves in rotator cuff arthropathy and after reverse shoulder arthroplasty: a prospective electromyographic analysis

Surface Electromyography Reveals Middle Deltoid as The Functionally Dominant Shoulder Muscle After Reverse Total Shoulder Arthroplasty

“…Anterior and posterior deltoid sEMG quantitative activation has also demonstrated an ability to predict postoperative range of motion, American Shoulder and Elbow Surgeons score, and Constant score, reaffirming the deltoid as the most important factor in postoperative RSA outcomes [3]. This has implications for both the surgeon and the patient in deciding which part of the deltoid to disrupt during an open rotator cuff repair approach [18,19]. Findings could also educate future RSA prosthesis design choices to maximize deltoid wrapping to increasing efficiency, strength, stability, and range of motion of the shoulder [20,21].…”

“…Surgeons may want to consider alternative approaches to the rotator cuff if a future RSA is likely. Furthermore, there is always a chance for complete or partial axillary or suprascapular nerve denervation when using a lateral shoulder approach [26][27][28][29][30] in addition to denervation that may occur during the RSA procedure itself [18,31]. Careful consideration should be given to maintain the integrity of the middle deltoid and associated nerves to preserve postoperative functionality.…”

Neurologic complications in primary anatomic and reverse total shoulder arthroplasty: A review

“…If an axillary nerve injury is identified on exam, an EMG is a reasonable next step to establish the baseline status and track recovery of the nerve. 26 An EMG may also pick up any subclinical changes in nerve function in patients with vague symptoms or persistent pain that cannot be reasonably explained by other causes. Once an axillary nerve injury has been identified, treatment consists of symptom management and clinical monitoring.…”

“…20 Similarly, Lopiz et al found that most of the axillary nerve lesions due to acute injury during shoulder replacement were transient and had no functional impact at final follow-up, with complete recovery seen on EMG at 6 months postoperatively. 26 6. Brachial plexus injury…”

“…Lopiz et al found that 47% of their 20 included patients has preoperative suprascapular nerve injury and 17% of the acute postoperative nerve lesions represented worsening of a preexisting lesion. 26 Thus, patients must be counseled regarding their risk for worsening of symptoms following shoulder replacement surgery.…”