Effect of Glenoid Bone Loss and Shoulder Position on Axillary Nerve Anatomy During the Latarjet Procedure.

BACKGROUND: The Latarjet procedure is increasingly being utilized for the treatment of glenoid bone loss and has a relatively high neurological complication rate. Understanding the position-dependent anatomy of the axillary nerve (AN) is crucial to preventing injuries. PURPOSE: To quantify the effects of changes in the shoulder position and degree of glenoid bone loss during the Latarjet procedure on the position of the AN. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 10 cadaveric shoulders were dissected, leaving the tendons of the rotator cuff and deltoid for muscle loading. The 3-dimensional position of the AN was quantified relative to the inferior glenoid under 3 conditions: (1) intact shoulder, (2) Latarjet procedure with 15% bone loss, and (3) Latarjet procedure with 30% bone loss. Measurements were obtained at 0°, 30°, and 60° of glenohumeral abduction (equivalent to 0°, 45°, and 90° of shoulder abduction) and at 0°, 45°, and 90° of humeral external rotation (ER). RESULTS: Abduction of the shoulder to 60° resulted in a posterior (9.5 ± 1.1 mm; P < .001), superior (3.0 ± 1.2 mm; P = .013), and lateral (19.1 ± 2.3 mm; P < .001) shift of the AN, and ER to 90° resulted in anterior translation (10.0 ± 1.2 mm; P < .001). Overall, ER increased the minimum AN-glenoid distance at 30° of abduction (14.9 ± 1.3 mm [0° of ER] vs 17.3 ± 1.5 mm [90° of ER]; P = .045). The Latarjet procedure with both 15 and 30% glenoid bone loss resulted in a superior and medial shift of the AN relative to the intact state. A decreased minimum AN-glenoid distance was seen after the Latarjet procedure with 30% bone loss at 60° abduction and 90° ER (17.7 ± 1.6 mm [intact] vs 13.9 ± 1.6 mm [30% bone loss]; P = .007), but no significant differences were seen after the Latarjet procedure with 15% bone loss. CONCLUSION: Abduction of the shoulder induced a superior, lateral, and posterior shift of the AN, and ER caused anterior translation. Interestingly, the Latarjet procedure, when performed on shoulders with extensive glenoid bone loss, significantly reduced the minimum AN-glenoid distance during shoulder abduction and ER. These novel findings imply that patients with substantial glenoid bone loss may be at a higher risk of AN injuries during critical portions of the procedure. Consequently, it is imperative that surgeons account for alterations in nerve anatomy during revision procedures. CLINICAL RELEVANCE: This study attempts to improve understanding of the position-dependent effect of shoulder position and glenoid bone loss after the Latarjet procedure on AN anatomy. Improved knowledge of AN anatomy is crucial to preventing potentially devastating AN injuries during the Latarjet procedure.

A rare presentation of a large suprascapular fossa lipoma causing suprascapular nerve traction injury leading to massive rotator cuff tear, treated arthroscopically - case report.

Suprascapular fossa lipoma extending to the suprascapular notch causing traction injury to the suprascapular nerve is a rare presentation. We report a 47-year-old male with progressive weakness of the right shoulder joint of 8 months duration, with a palpable mass over the spine of the scapula was noticed 2 months earlier and developed a sudden drop in arm following a moderate strain. A magnetic resonance imaging (MRI) scan revealed a rotator cuff tear involving the supraspinatus and infraspinatus muscles with a tumor like lesion in the suprascapular fossa, displacing the suprascapular muscle mass and extending into the suprascapular notch. Electromyography and nerve conduction velocity studies revealed suprascapular neuropathy. After histopathologic confirmation, an arthroscopic excision of the mass with decompression of the suprascapular notch was performed along with repair of the rotator cuff. Six months after the procedure, the patient had improved considerably in terms of function and postoperative MRI revealed a complete excision of the mass, and further follow-up of 2 years showed no recurrence. Suprascapular nerve entrapment can be caused by a lipoma in the shoulder, leading to weakness, atrophy, and consequent tear of the rotator cuff tendons. Arthroscopic management, after histopathological confirmation, gives good results in this situation. LEVEL OF EVIDENCE: Level IV.

Risk of suprascapular nerve injury in open Trillat procedure: an anatomical study.

PURPOSE: The open Trillat Procedure described to treat recurrent shoulder instability, has a renewed interest with the advent of arthroscopy. The suprascapular nerve (SSN) is theoretically at risk during the drilling of the scapula near the spinoglenoid notch. The purpose of this study was to assess the relationship between the screw securing the coracoid transfer and the SSN during open Trillat Procedure and define a safe zone for the SSN. METHODS: In this anatomical study, an open Trillat Procedure was performed on ten shoulders specimens. The coracoid was fixed by a screw after partial osteotomy and antero-posterior drilling of the scapular neck. The SSN was dissected with identification of the screw. We measured the distances SSN-screw (distance 1) and SSN-glenoid rim (distance 2). In axial plane, we measured the angles between the glenoid plane and the screw (α angle) and between the glenoid plane and the SSN (ß angle). RESULTS: The mean distance SSN-screw was 8.8 mm +/-5.4 (0-15). Mean α angle was 11°+/-2.4 (8-15). Mean ß angle was 22°+/-6.7 (12-30). No macroscopic lesion of the SSN was recorded but in 20% (2 cases), the screw was in contact with the nerve. In both cases, the ß angle was measured at 12°. CONCLUSION: During the open Trillat Procedure, the SSN can be injured due to its anatomical location. Placement of the screw should be within 10° of the glenoid plane to minimize the risk of SSN injury and could require the use of a specific guide or arthroscopic-assisted surgery.

Winged Scapula: Clinical and Electrophysiological Features and Common Causes Based on 20 Years of Experience in a Referral Center in Turkey.

PURPOSE: Winged scapula (WS) is a functionally disabling problem and it occurs because of neurogenic causes frequently. The authors aimed to assess WS patients by physical and electrodiagnostic examinations as well as some further investigations and define the common causes of WS. METHODS: The authors reviewed clinical and neurophysiological findings of 52 patients who were referred for electrodiagnostic examination because of WS in the period of 20 years. RESULTS: The mean age was 39 (range, 11-73) years and 32 were male patients. Right side was involved in 60% of patients (n = 31). According to electrodiagnostic examinations, 44 patients (85%) had neurogenic causes; 29 spinal accessory nerve palsy (17 occurred after surgical procedure), nine long thoracic nerve palsy (four occurred after strenuous activity), two dorsal scapular nerve (both neuralgic amyotrophy), one long thoracic nerve and spinal accessory nerve (relevant with strenuous trauma), one spinal accessory nerve and dorsal scapular nerve palsies (after surgical procedure and radiotherapy), one C5-7 radiculopathy (avulsion), and one brachial plexopathy (obstetric trauma). Five patients (10%) had muscle-related findings (four facio-scapulo-humeral dystrophy and one Duchenne muscular dystrophia) and three patients (5%) had normal findings (bone-joint related). CONCLUSIONS: This study presents a relatively large series of patients with WS because of several causes from a referral tertiary EMG laboratory. The authors found that spinal accessory nerve palsy after neck surgery is the most common cause and long thoracic nerve palsy is the second common cause of unilateral WS. Electrodiagnostic examinations should be performed in WS patients to establish exact diagnosis and reveal some coexistence of WS causes.

[Neurological shoulder pain and weakness : practical attitudes]. / Douleurs et faiblesse de l'épaule neurologique : attitudes pratiques.

Shoulder pain or paresis should be assessed carefully, as there are many possible causes, which can be osteoarticular, degenerative, inflammatory, or neurological. Weakness or pain can be related to cervicobrachialgia, plexitis, or focal mononeuropathy. The clinical picture should identify any muscular or mechanical origin of paresis responsible for pseudo-paretic functional limitation. Neurogenic scapulalgia with functional deficit implies the compression or entrapment of a nerve trunk including the axillary, long thoracic, accessory, suprascapular, or dorsal scapular nerves. Nerve conduction study and myography together with medical imaging help to identify the relevant etiology. Treatment mostly includes pain relief and physiotherapy, but surgery is rarely necessary.

L'épaule douloureuse ou parétique est d'appréhension délicate et de causes variées : ostéoarticulaire, dégénérative, inflammatoire ou neurologique. La faiblesse ou la douleur peuvent être liées à une cervicobrachialgie, une plexite ou une mononeuropathie focale. Le tableau clinique doit distinguer une parésie d'origine musculaire ou mécanique responsable alors d'une limitation fonctionnelle pseudo-parétique. Une scapulalgie déficitaire neurogène implique la recherche d'une mononeuropathie d'enclavement ou compressive d'un tronc nerveux, axillaire, long thoracique, accessoire du XIe nerf crânien, suprascapulaire ou dorsal de la scapula. Au besoin l'ENMG (électroneuromyogramme)et l'imagerie débrouilleront les multiples étiologies. Le traitement requiert le plus souvent une antalgie et une rééducation, rarement une chirurgie.

Accuracy of sonographic identification of suprascapular nerve at supraclavicular fossa: a cadaveric study / Precisión de la identificación ecográfica del nervio supraescapular en la fosa supraclavicular: un estudio cadavérico

SUMMARY: Sonographic identification of suprascapular nerve (SSN) is essential for diagnosis of suprascapular neuropathy and ultrasound-guided suprascapular nerve block. This study aims to demonstrate the accuracy of identification of SSN at supraclavicular region by ultrasonography in fresh cadavers. Ninety-three posterior cervical triangles were examined. With ultrasonography, SSN emerging from the upper trunk of brachial plexus was identified and followed until it passed underneath the inferior belly of omohyoid muscle. Sonographic visualization of SSN in supraclavicular fossa was recorded. Then, cadaveric dissection was performed to determine the presence or absence of SSN. An agreement between sonographic identification and direct visualization was specified and categorized the following three patterns: "correctly identified" (pattern I), "incorrectly identified" (pattern II), and "unidentified" (pattern III). The identification of SSN using sonography was correct in almost 90 %. The diameter of SSN with pattern I was the largest compared to those of other two patterns. In pattern I, SSN ran laterally from the upper trunk of brachial plexus and passed underneath the inferior belly of omohyoid muscle. Therefore, SSN was easily identified under ultrasonography. In pattern II, nerve identified by ultrasonography was literally the dorsal scapular nerve. In pattern III, SSN was unable to be identified because of its anatomical variation. The accuracy of ultrasonographic identification of SSN at supraclavicular fossa is high and the key sonoanatomical landmarks are the lateral margin of brachial plexus and the inferior belly of omohyoid muscle. The anatomical variants of SSN are reasons of incorrect or unable identification of SSN under ultrasonography.

RESUMEN: La identificación ecográfica del nervio supraescapular (NSE) es esencial para el diagnóstico de neuropatía supraescapular y bloqueo del nervio supraescapular mediante la ecografía. Este estudio tiene como objetivo demostrar la precisión de la identificación de NSE en la región supraclavicular por ecografía en cadáveres frescos. Se examinaron noventa y tres triángulos cervicales posteriores. Se identificó el NSE emergente de la parte superior del tronco del plexo braquial con la ecografía, y se siguió hasta su trayecto por debajo del vientre inferior del músculo omohioideo. Se registró la visualización ecográfica del NSE en la fosa supraclavicular. Luego, se realizó disección cadavérica para determinar la presencia o ausencia de NSE. Se especificó un acuerdo entre la identificación ecográfica y la visualización directa y se categorizaron los siguientes tres patrones: "identificado correctamente" (patrón I), "identificado incorrectamente" (patrón II) y "no identificado" (patrón III). La identificación de NSE mediante ecografía fue correcta en casi el 90 %. El diámetro del NSE con el patrón I fue el más grande en comparación con los de los otros dos patrones. En el patrón I, NSE corría lateralmente desde la parte superior del tronco del plexo braquial y pasaba por debajo del vientre inferior del músculo omohioideo. Por lo tanto, el NSE se identificó fácilmente mediante ecografía. En el patrón II, el nervio identificado por ecografía era literalmente el nervio escapular dorsal; en el patrón III, el NSE no pudo ser identificado debido a su variación anatómica. La precisión de la identificación ecográfica del NSE en la fosa supraclavicular es alta y los puntos de referencia sonoanatómicos clave son el borde lateral del plexo braquial y el vientre inferior del músculo omohioideo. Las variantes anatómicas de NSE son razones de identificación incorrecta o incapaz de NSE bajo ecografía.

Decompression of the suprascapular nerve at the suprascapular notch under combined arthroscopic and ultrasound guidance.

Decompression of the suprascapular nerve (SSNe) at the suprascapular notch (SSNo) is usually performed with an arthroscopic procedure. This technique is well described but locating the nerve is complex because it is deeply buried and surrounded by soft tissue. We propose to combine ultrasound and arthroscopy (US-arthroscopy) to facilitate nerve localization, exposure and release. The main objective of this study was to assess the feasibility of this technique. This is an experimental, cadaveric study, carried out on ten shoulders. The first step of our technique is to locate the SSNo using an ultrasound scanner. Then an arthroscope is introduced under ultrasound control to the SSNo. A second portal is then created to dissect the pedicle and perform the ligament release. Ultrasound identification of the SSNo, endoscopic dissection and decompression of the nerve were achieved in 100% of cases. Ultrasound identification of the SSNo took an average of 3 min (± 4) while dissection and endoscopic release time took an average of 8 min (± 5). Ultrasound is an extremely powerful tool for non-invasive localization of nerves through soft tissues, but it is limited by the fact that tissue visualization is limited to the ultrasound slice plane, which is two-dimensional. On the other hand, arthroscopy (extra-articular) allows three-dimensional control of the surgical steps performed, but the locating of the nerve involves significant tissue detachment and a risk of damaging the nerve with the dissection. The combination of the two (US-arthroscopy) offers the possibility of combining the advantages of both techniques.

Suprascapular nerve block is a clinically attractive alternative to interscalene nerve block during arthroscopic shoulder surgery: a meta-analysis of randomized controlled trials.

BACKGROUND: The interscalene brachial plexus block (ISB) is a commonly used nerve block technique for postoperative analgesia in patients undergoing shoulder arthroscopy surgery; however, it is associated with potentially serious complications. The use of suprascapular nerve block (SSNB) has been described as an alternative strategy with fewer reported side effects for shoulder arthroscopy. This review aimed to compare the impact of SSNB and ISB during shoulder arthroscopy surgery. METHODS: A meta-analysis was conducted to identify relevant randomized controlled trials involving SSNB and ISB during shoulder arthroscopy surgery. Web of Science, PubMed, Embase, Cochrane Controlled Trials Register, Cochrane Library, Highwire, CNKI, and Wanfang database were searched from 2010 through March 2021. RESULTS: We identified 1255 patients assessed in 17 randomized controlled trials. Compared with the ISB group, the SSNB group had higher VAS at rest in PACU (P = 0.003), 1 h after operation (P = 0.005), similar pain score 2 h (P = 0.39), 3-4 h (P = 0.32), 6-8 h after operation (P = 0.05), then lower VAS 12 h after operation (P = 0.00006), and again similar VAS 1 day (P = 0.62) and 2 days after operation (P = 0.70). As for the VAS with movement, the SSNB group had higher pain score in PACU (P = 0.03), similar VAS 4-6 h after operation (P = 0.25), then lower pain score 8-12 h after operation (P = 0.01) and again similar VAS 1 day after operation (P = 0.3) compared with the ISB group. No significant difference was found for oral morphine equivalents use at 24 h (P = 0.35), duration of PACU stay (P = 0.65), the rate of patient satisfaction (P = 0.14) as well as the rate of vomiting (P = 0.56), and local tenderness (P = 0.87). However, the SSNB group had lower rate of block-related complications such as Horner syndrome (P < 0.0001), numb (P = 0.002), dyspnea (P = 0.04), and hoarseness (P = 0.04). CONCLUSION: Our high-level evidence established SSNB as an effective and safe analgesic technique and a clinically attractive alternative to interscalene block with the SSNB'S advantage of similar pain control, morphine use, and less nerve block-related complications during arthroscopic shoulder surgery, especially for severe chronic obstructive pulmonary disease, obstructive sleep apnea, and morbid obesity. Given our meta-analysis's relevant possible biases, we required more adequately powered and better-designed RCT studies with long-term follow-up to reach a firmer conclusion.

Clinical Outcomes of Arthroscopic Suprascapular Nerve Decompression for Suprascapular Neuropathy.

PURPOSE: To report clinical outcomes following arthroscopic suprascapular nerve (SSN) decompression for suprascapular neuropathy at the suprascapular and/or spinoglenoid notch in the absence of major concomitant pathology. METHODS: We retrospectively reviewed prospectively collected data of 19 patients who underwent SSN release at the suprascapular and/or spinoglenoid notch between April 2006 and August 2017 with ≥2 years of follow-up. Patients who underwent concomitant rotator cuff or labral repairs or had severe osteoarthritis were excluded. Pre- and postoperative strength and patient-reported outcomes were collected, including the American Shoulder and Elbow Surgeons (ASES), Single Assessment Numerical Evaluation (SANE), Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH), 12-item Short Form (SF-12), and satisfaction. Complications and revisions were recorded. RESULTS: At a mean final follow-up of 4.8 years, pre- to postoperative ASES (64.9 ± 18.7 versus 83.5 ± 23.1; P = .018), QuickDASH (28.7 ± 17.2 versus 12.7 ± 17.1; P = .028), SANE (64.3 ± 16.4 versus 80.8 ± 22.3; P = .034), and SF-12 PCS (41.1 ± 10.8 versus 52.3 ± 5.8; P = .007) scores all significantly improved. Median strength for external rotation improved significantly (4 [range 2 to 5] versus 5 [range 3 to 5]; P = .014). There was no statistically significant improvement in median strength for abduction (4 [range 3 to 5] versus 5 [5]; P = .059). Median postoperative satisfaction was 9 (range 1 to 10), with 8 patients (50%) rating satisfaction ≥9. No complications were observed, and no patients went on to revision surgery. CONCLUSION: Arthroscopic SSN decompression for suprascapular neuropathy at the suprascapular and/or spinoglenoid notch in the absence of major concomitant glenohumeral pathology results in good functional outcomes with significant improvements from before to after surgery. LEVEL OF EVIDENCE: IV, therapeutic case series.

Applied anatomical study on suprascapular nerve protection in reverse total shoulder arthroplasty.

BACKGROUND: This study aimed to investigate the three-dimensional (3D) anatomical relationship between the suprascapular nerve and scapula, and the method of protecting the suprascapular nerve in reverse total shoulder arthroplasty (RTSA) METHODS: In the present study, 12 fresh adult cadaver shoulder specimens were dissected. X-ray and computed tomography (CT) were used to investigate the 3D scapular and suprascapular nerve images. RESULTS: The results revealed that the best fitting baseplate diameter was 24.73 ± 1.56 mm. Furthermore, the baseplate diameter correlated with the glenoid cavity width. After the osteotomy, a simulated screw placement on the baseplate was performed. The dangerous area for the posterior screw placement was at the angle between the upper edge and transverse axis exceeding 38° and between the lower edge and transverse axis exceeding 76°. The distance between the nearest point of the nerve and osteotomy plane was 15.38 ± 2.02 mm, and the angle between the projection point of the nearest point and transverse axis was 27.33 ± 7.96°, which was the dangerous area for retractor placement. The suitable angle between the superior screw and longitudinal axis was 21.67 ± 13.27°, and the suitable superior screw length was 34.66 ± 2.41 mm. CONCLUSION: In RTSA, the baseplate size correlates with the glenoid cavity width. The relationship between the screw and suprascapular nerve and retractor placement position should be carefully considered to avoid damaging the suprascapular nerve.

The Evaluation and Management of Suprascapular Neuropathy.

Suprascapular neuropathy is a potential source of shoulder pain and functional limitation that can present secondary to various etiologies including entrapment or compression. Cystic lesions arising from a labral or capsular tear can compress the nerve along its course over the scapula. Nerve traction is theorized to arise from chronic overhead athletics or due to a retracted rotator cuff tear. The diagnosis of suprascapular neuropathy is based on a combination of a detailed history, a comprehensive physical examination, imaging, and electrodiagnostic studies. Although the anatomic course and variations in bony constraint are well understood, the role of surgical treatment in cases of suprascapular neuropathy is less clear. Recent reviews on the topic have shed light on the outcomes after the treatment of suprascapular neuropathy because of compression, showing that surgical release can improve return to play in well-indicated patients. The incidence of compressive neuropathy is quite high in the overhead athletic cohort, but most patients do not show clinically relevant deficiencies in function. Surgical release is therefore not routinely recommended unless patients with pain or deficits in strength fail appropriate nonsurgical treatment.

Suprascapular nerve decompression in addition to rotator cuff repair: a prospective, randomized observational trial.

BACKGROUND: Tear and retraction of the supraspinatus (SS) and infraspinatus (IS) musculotendinous units and/or their repair may be associated with traction damage to the suprascapular nerve, potentially responsible for pain or weakness of the rotator cuff (RC). Arthroscopic release of the transverse scapular ligament at the suprascapular notch has been advocated to prevent or treat suprascapular nerve impairment associated with RC retraction and/or repair. The effect of this procedure on preoperative normal nerve function is, however, not well studied.We hypothesize that (1) decompression of the suprascapular nerve without preoperative pathologic neurophysiological findings will not improve clinical or imaging outcome and (2) suprascapular decompression will not measurably change suprascapular nerve function. METHODS: Nineteen consecutive patients with a magnetic resonance arthrography documented RC tear involving SS and IS but normal preoperative electromyography (EMG)/nerve conduction studies of the SS and IS were enrolled in a prospective, controlled trial involving RC repair with or without suprascapular nerve decompression at the suprascapular notch. Nine patients were randomized to undergo, and 10 not to undergo, a decompression of the suprascapular nerve. Patients were assessed clinically (Constant score, mobility, pain, strength, subjective shoulder value), with magnetic resonance imaging and neurophysiology preoperatively and at 3- and 12-month follow-up. RESULTS: There was no clinically relevant difference between the release and the non-release group in any clinical parameter at any time point. At magnetic resonance imaging, there was a slightly greater increase of fatty infiltration of the IS in the release group without any other differences between the 2 groups. Electromyographically, there were no pathologic findings in the non-release group at any time point. Conversely, 3 of the 9 patients of the release group showed pathologic EMG findings at 3 months, of whom 2 had recovered fully and 1 only partially at 12 months. CONCLUSION: In the presence of normal EMG findings, suprascapular nerve release added to arthroscopic RC repair is not associated with any clinical benefit, but with electromyographically documented, postoperative impairment of nerve function in 1 of 3 cases. Suprascapular nerve release does not therefore seem to be justified as an adjunct to RC repair if preoperative EMG findings document normal suprascapular nerve function. Based on these findings, the ongoing prospective randomized trial was terminated.

Winged scapula following axillary thoracotomy with long thoracic nerve preservation.

Winged scapula is a rare condition caused by injuries to the long thoracic nerve (LTN) and accessory nerves. A 69-year-old man underwent surgery for right lung cancer. Video-assisted thoracic surgery was converted to axillary thoracotomy at the fourth intercostal space. The latissimus dorsi was protected, and the serratus anterior was divided on the side anterior to the LTN. Two months after discharge, he presented with difficulty in elevating his right arm and protrusion of the scapula from his back. Active forward flexion of the right shoulder was limited to 110° and abduction to 130°. He was diagnosed with winged scapula. After 6 months of occupational therapy, the symptoms improved. The LTN may have been overstretched or damaged by the electric scalpel. We recommend an increased awareness of the LTN, and to divide the serratus anterior at a site as far as possible from the LTN to avoid postoperative winged scapula.

An anatomical study of the superior transverse scapular ligament of Jining population.

PURPOSE: The aim of this study was to determine the anatomical variations of the superior transverse scapular ligament (STSL) for better understanding the possible predisposing factors for suprascapular nerve entrapment. METHODS: The study was using fifty 10% formalin solution-fixed human cadaveric shoulders. After dissection of the suprascapular region, the length, medial width, lateral width and middle width of the suprascapular opening were measured for each STSL. RESULTS: The STSL displayed six types as: (1) band-shaped in 11 cases; (2) fan-shaped in 27 cases; (3) triangular-shaped in 5 cases; (4) linear type in 2 cases; (5) bifid in 1 case; (6) absent in 1 case. The ossified type of STSL was found in 3 cases. There were statistically significant differences in the length (P = 0.009), medial width (P = 0.001), lateral width (P = 0.029) of the three types of fan-shaped, band-shaped and triangular-shaped. However, there was no statistical difference in the middle width of the suprascapular opening of the three types (P = 0.340). CONCLUSION: Knowing the morphological features and variations of the STSL is important for better understanding the anatomical conditions, which could be taken into consideration during open suprascapular operations or arthroscopic decompressions.

MRI diagnosis of suprascapular neuropathy using spinoglenoid notch distension.

PURPOSE: To assess the use of a spinoglenoid notch distension measurement as a radiographic marker on MRI to aid the diagnosis of suprascapular neuropathy. METHODS: Spinoglenoid notch distension was compared on MRI by blinded independent observers for two patient cohorts: one group with an electromyography/nerve conduction study confirmed diagnosis of suprascapular neuropathy who underwent arthroscopic suprascapular nerve decompression, and a control group of patients aged 18-30 years with a normal shoulder MRI. RESULTS: Sixty suprascapular nerve patients (average age 52 years) were compared to 47 control patients (average age 24 years). Intra-rater and inter-rater reliability showed excellent agreement between reviewers for all measurements. There was a significant difference in the mean spinoglenoid notch distension for the SSN group (m = 8.36, SD = 2.42) compared to the control group (m = 5.7, SD = 1.56); [t(212) = 9.40, p < 0.0001]. CONCLUSION: The spinoglenoid notch distension is significantly increased in patients with suprascapular neuropathy. We hypothesize that hypertrophy of the transverse scapular ligament creates a venous obstruction resulting in varicosities of the suprascapular vein which runs with the nerve under the ligament. This distends the spinoglenoid notch and can be enlarged in cases of suprascapular neuropathy which is evident on MRI.

The surgical anatomy of the dorsal scapular nerve: a triple-tendon transfer perspective.

BACKGROUND: Iatrogenic or traumatic injury to the spinal accessory nerve is a rare but debilitating injury. An effective treatment, known as the Eden-Lange modification triple-tendon transfer procedure, involves the transfer of the rhomboid major (RM), rhomboid minor (Rm), and levator scapulae (LS). Careful detachment of their insertions is necessary to avoid injury of the dorsal scapular nerve (DSN). This study evaluated the surgical anatomy and safety of the DSN relative to this procedure. METHODS: The study used 12 cadavers (22 shoulders). The RM, Rm, and LS were detached from their insertions, and the DSN was dissected. Measurements were taken to evaluate the anatomy of each relative to the triple-tendon transfer procedure. Additional measurements were taken to identify "danger zones" for DSN injury, regarding detachment of RM, Rm, and LS from their respective insertions. RESULTS: Measurements of the 22 shoulders included in the study showed wide variation in anatomy. The minimum distance between the scapula and the DSN at the vertebral scapular border was 0.7 cm, suggesting that care and precision are needed to perform this technique. The region where the DSN crosses the superior border of the Rm was shown to be the greatest "danger zone" of this technique, with a mean distance to the scapula of 1.61 ± 0.53 cm CONCLUSIONS: This study provides insight into the surgical anatomy of the DSN relative to a rare but successful procedure used to treat trapezius paralysis. The results of this study can inform the surgeon regarding potential anatomic considerations when performing the triple-tendon transfer.

A rare sonographic finding for suprascapular nerve entrapment: engorged suprascapular artery not vein.

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Spinal accessory nerve repair using a direct nerve transfer from the upper trunk: results with 2 years follow-up.

Spinal accessory nerve grafting requires identification of both nerve stumps in the scar tissue, which is sometimes difficult. We propose a direct nerve transfer using a fascicle from the posterior division of the upper trunk. We retrospectively reviewed 11 patients with trapezius palsy due to an iatrogenic injury of the spinal accessory nerve in nine cases. The mean age was 38 years (range 21-59). Preoperatively, patients showed shoulder weakness and limited range of motion. At a mean follow-up of 25 months, active shoulder abduction improvement averaged 57°. Trapezius muscle strength graded M4 or M5 in 10 cases and M3 in one case. No deltoid or triceps impairment was reported. Scapula kinematics was considered normal in seven patients. This technique gave satisfactory functional results and may be an alternative to spinal accessory nerve grafting for the management of trapezius palsies if direct repair is not feasible. LEVEL OF EVIDENCE: IV.

Evaluation of Risk to the Suprascapular Nerve During Arthroscopic SLAP Repair: Is a Posterior Portal Safer?

PURPOSE: The purpose of this study was to compare the risk of glenoid perforation during SLAP repair for suture anchors placed through an anterolateral portal versus a posterolateral portal of Wilmington. METHODS: Ten bilateral cadaveric shoulders were randomized to suture anchor placement through an anterolateral portal on one shoulder and a posterolateral portal on the contralateral shoulder. Anchors were placed into anterior, posterior, and far posterior positions on the glenoid rim (1 o'clock, 11 o'clock, and 10 o'clock positions for right shoulders). The shoulder was then dissected, and the distance from the suture anchor tip to the nerve was measured if perforation occurred. The maximum load and failure mechanism of each anchor was assessed with a materials testing system machine. RESULTS: Only 2 of 20 anchors placed in the posterosuperior glenoid through the posterolateral portal perforated compared with 16 of 20 of the anchors placed through the anterolateral portal (P < .05). The mean distance from the perforated anchor tip to the suprascapular nerve was 2.5 ± 1.4 mm for the anterolateral portal and 4.4 ± 0.6 mm for the posterolateral portal (P = .18). We did not observe a significant difference in biomechanical strength (P > .05). CONCLUSIONS: There is a high rate of glenoid perforation in close proximity to the suprascapular nerve when placing anchors in the posterosuperior glenoid through an anterolateral portal. Use of the posterolateral portal results in a much lower incidence of glenoid perforation for anchors placed in the posterosuperior glenoid, but there is a higher risk of glenoid perforation for an anchor placed in the anterosuperior glenoid from the posterolateral portal. CLINICAL RELEVANCE: There is a higher risk of injury to the suprascapular nerve when suture anchors are placed in the posterosuperior glenoid through an anterolateral portal compared with a posterolateral portal for SLAP repair.