Suprascapular nerve injury after reverse total shoulder arthroplasty: correlation with screw out of vault penetration and functional situation: prospective study.

BACKGROUND: Baseplate screws have been suggested as a possible cause of suprascapular neuropathy after reverse total shoulder arthroplasty. This study aims to investigate the association between screw penetration out of the vault, electromyographic study, and the clinical outcomes. METHODS: A total of 31 patients who underwent reverse total shoulder arthroplasty for cuff tear arthropathy were prospectively enrolled. They were followed up for a minimum of 24 months. All patients underwent computed tomography 6 months postoperatively to determine the extraosseous position of the screws (perforation of the second bone cortex and protrusion into the supra- or infraspinatus fossa). Electrodiagnostic evaluation was performed preoperatively and postoperatively to stablish any relation between cortex perforation of the screw and suprascapular nerve (SSN) injury. Clinical outcomes pre- and postoperatively (Constant score, ranges of motion, and visual analog scale) of patients with and without documented injury were recorded. RESULTS: A total of 14 patients (45.2%) had an abnormal preoperative SSN electrodiagnostic study (chronic or disuse injuries), and 6 patients (19.4%) had an abnormal postoperative study (acute injury). Of the 6 patients, 2 cases appeared over the pre-existing lesion and 4 appeared over an intact preoperative nerve, all of them affecting the infraspinatus branch of the SSN. Perforation of the second cortex was detected for 60% of superior screws and 40% of posterior screws. The mean lengths of the superior and posterior screws were 30 and 18.2 mm, respectively. Patients with screw perforation of the second cortex were assessed as having a high risk of nerve injury (40% vs. 9.5%). CONCLUSIONS: Preoperative SSN injuries do not have a significant clinical impact and do not predispose to an acute postoperative SSN lesion. The Constant score and visual analog scale score for patients with acute SSN injuries were not statistically different from those without SSN injury. The extraosseous position of the screw increases the probability of an SSN injury to 31%. This risk is higher with the posterior screw, which leads us to question whether it is really necessary to use it.

Klippel-Trenaunay-Weber Syndrome Associated with Multiple Cerebral Arteriovenous Malformations: Usefulness of Gamma Knife Stereotactic Radiosurgery in This Syndrome.

BACKGROUND: Klippel-Trenaunay-Weber syndrome (KTWS) is characterized by the presence of a combined vascular malformation of capillaries, veins, and lymphatic vessels; congenital venous abnormalities; and limb hypertrophy. Its association with neurovascular abnormalities is infrequent, and the presence of intracranial arteriovenous malformations (AVMs) is extremely rare. CASE DESCRIPTION: We report a case of a 48-year-old male diagnosed with KTWS who spontaneously presented with a cerebral hemorrhage. Computed tomography scan and angio-computed tomography studies revealed bleeding associated with AVM rupture. In the conventional arteriography study, 10 small (<1 cm) AVMs were observed. The patient presented a good clinical recovery. These multiple small lesions were not considered susceptible to surgical or endovascular treatments. Therefore all lesions were treated with Gamma Knife stereotactic radiosurgery since it attains the highest dose drop and minimal irradiation of the healthy parenchyma. One year after the treatment, the lesions have shrunk. CONCLUSIONS: Cerebral AVMs are extremely rare in KTWS cases; however, their presence can have serious consequences if they are treated. We find it advisable to include brain imaging tests, such as nuclear magnetic resonance imaging, to diagnose and monitor KTWS. Furthermore, a Gamma Knife may be useful when multiple AVMs are present.