Suprascapular Nerve Compression Research Articles

Interobserver and Intraobserver Variability of Four Suprascapular Notch Classification Systems.

Knowledge of the morphology of the suprascapular notch is clinically beneficial in patients withsuspected suprascapular nerve compression or palsy. Several classification systems have been proposed for the morphological classification of the suprascapular notch and its severalanatomical variations. The purpose of this study was to evaluate the inter- and intraobserver reliability of four different classification systems for suprascapular notch typing analysing shoulder computed tomography (CT) scans. Shoulder CT scans from 109 subjects (71.5% males) were examined by three raters of various experience levels, one senior, one experienced, and one junior orthopaedic surgeon. The CT scans were evaluated quantitatively and qualitatively and the suprascapular notch was classified according to four classification systems at two separate timepoints, four weeks apart. To determine consistency among the same or different raters, the Kappa statistic was performed and intrarater reliability for each rater between the first and the second evaluation was assessed using Cohen's kappa. Reliability across all raters at each timepoint was assessed using the Fleiss kappa. Agreement was almost perfect for all the classification systems and amongst all raters, regardless of their experience level. There were no significant differences between the raters on any of the evaluations. The overall interobserver agreement for all classifications was almost perfect. The four suprascapular notch classification systems are reliable, and the rater's experience level has no impact on the evaluation.

Arthroscopic repair of the supraspinatus tendon with single-stage decompression of the suprascapular nerve at the superscapular notch

The history of shoulder problems dates back to ancient times, and the shoulder joint plays a significant role in various aspects of human life. Throughout history, doctors have been providing assistance to individuals experiencing shoulder pain. In the 20th century, significant advancements were made in shoulder surgery, driven by an improved understanding of joint biomechanics and the recognition of new diagnostic methods. Arthroscopy, a minimally invasive surgical technique, was first used for diagnosing shoulder conditions only about 30 years ago. Since then, it has replaced many open surgical procedures due to its enhanced visualization capabilities and lower invasiveness, leading to reduced injury rates. Suprascapular nerve decompression at the suprascapular notch is an example of a procedure that has benefited from arthroscopy. Dr. Laurent Lafosse's detailed description of arthroscopic manipulation in 2007 has been crucial in advancing this technique.This article aims to shed light on the pathogenesis of suprascapular nerve compression at the suprascapular notch following supraspinatus tendon retraction and examine the potential complications of suprascapular neuropathy. The principal author of this article has successfully performed 20 supraspinatus tendon repair operations with simultaneous decompression of the suprascapular nerve at the suprascapular notch, achieving positive outcomes in the postoperative period.

Surgical Decompression for Acute Axillary and Suprascapular Neuropathy

Case: We present the case of a 25-year-old man, who sustained a ground level fall and presented with a left shoulder inferior labral tear with paralabral cyst and associated axillary nerve compression. He had electromyogram evidence of axillary and suprascapular nerve compression. Surgical decompression of the cyst, repair of the labrum, and suprascapular notch decompression relieved his previously progressive symptoms. Conclusion: This case demonstrates that individuals who have a paralabral cyst with acute, severe axillary neuropathy and suprascapular neuropathy can benefit from decompression of the paralabral cyst, repair of the labrum, and decompression of the suprascapular notch.

Ossification of Superior Transverse Scapular Ligament - Incidence, Embryology and Association with Suprascapular Neuropathy.

Suprascapular notch is present at superior border of scapula just medial to coracoid process. This is covered by superior transverse scapular ligament (STSL). Suprascapular nerve passes below this ligament while suprascapular vessels pass above it. STSL ossification is a rare finding with variable incidences in different population groups. We observed 60 dry bony scapulae, 30 prosected formalin fixed upper limbs with scapula and 10 embalmed cadavers for the presence of ossified STSL. There were complete ossification of STSL in two dried bony specimens of sacpula. Ossified STSL may be the causative factor for suprascapular neuropathy. The mainstay of management in cases of neuropathy or compression of suprascapular nerve is release of suprascapular ligament by either open or arthroscopic surgical approach. So, it is extremely important to know this type of variation to minimize any damage to related structure and plan the management accordingly.

Endoscopic/arthroscopic decompression of the suprascapular nerve at the spinoglenoid notch: indications and surgical technique

Suprascapular nerve compression at the spinoglenoid notch can lead to posterior shoulder pain, muscle weakness, and longstanding muscle atrophy of the infraspinatus. Although rare, it is most commonly seen in overhead athletes and laborers who perform repetitive overhead activities. Early diagnosis requires a thorough history and physical examination including imaging, diagnostic injections, and electromyography to avoid a missed diagnosis. While a course of nonoperative treatment is most often prescribed, early surgical intervention may be prudent to avoid irreversible damage especially if a space occupying lesion is present. This article will describe the history, physical examination findings, diagnostic workup, and our surgical technique for arthroscopic decompression of the suprascapular nerve at the spinoglenoid notch through a simple posterior approach avoiding the subacromial space.

Suprascapular Nerve Entrapment at the Spinoglenoid Notch By A Ganglion Cyst

Suprascapular nerve entrapment at the spinoglenoid notch by a ganglion cyst results in the paralysis of the terminal motor branch of the nerve, with isolated atrophy of the infraspinatus muscle, loss of strength in external rotation, and posterior shoulder pain. Increased awareness of this nerve compression is paramount in order to avoid the stage of irreversible infraspinatus muscle wasting and long term disability. Magnetic resonance imaging scan, electromyography and nerve conduction velocity studies can confirm the diagnosis and lead to an early arthroscopic nerve decompression and favorable functional results. We present a rare case of spinoglenoid ganglion cyst compression of the distal suprascapular nerve and discuss the recent developments in anatomy, aetiology, diagnosis, and review the treatment and current trends in the management of this condition.

Morphometry and Contents of the Suprascapular Notch with Potential Clinical Implications: Α Cadaveric Study.

Background The suprascapular notch (SN) represents the point along the route of the suprascapular nerve (SSN) with the greatest potential risk for injury and compression. Thus, factors reducing the area of the notch have been postulated for suprascapular neuropathy development. Methods Thirty-one fresh-frozen shoulders were dissected. The contents of the SN were described according to four types as classified by Polguj et al and the middle-transverse diameter of the notch was measured. Also, the presence of an ossified superior transverse scapular ligament (STSL) was identified. Results The ligament was partially ossified in 8 specimens (25.8%), fully ossified in 6 (19.35%), and not ossified in the remaining 17 (54.85%). The mean middle-transverse diameter of the SN was 9.06 mm (standard deviation [SD] = 3.45). The corresponding for type-I notches was 8.64 mm (SD = 3.34), 8.86 mm (SD = 3.12) was for type-II, and 14.5 mm (SD = 1.02) was for type III. Middle-transverse diameter was shorter when an ossified ligament was present (mean = 5.10 mm, SD = 0.88 mm), comparing with a partially ossified ligament (mean =7.67 mm, SD = 2.24 mm) and a nonossified one (mean = 11.12 mm, SD = 2.92 mm). No statistically significant evidence was found that the middle-transverse diameter depends on the number of the elements, passing below the STSL. Conclusion Our results suggest that SSN compression could be more likely to occur when both suprascapular vessels pass through the notch. Compression of the nerve may also occur when an ossified transverse scapular ligament is present, resulting to significant reduction of the notch's area.

Arthroscopic Decompression of Spinoglenoid Notch Cyst and SLAP Repair Through a Single Working Portal

A SLAP lesion can be found with a concomitant spinoglenoid notch cyst. The cyst can cause suprascapular nerve compression, resulting in shoulder pain and weakness of external rotation. Their management varies from conservative treatment to operative treatment. Cyst decompression through the labral tear is our preferred treatment. Previous studies demonstrated a good result after arthroscopic decompression of the cyst through the labral tear combined with SLAP repair. Many surgeons usually use 3 portals to perform this procedure. However, we prefer to use only 2 portals, 1 anterior viewing portal and 1 posterior working portal. This strategy is more time and cost efficient. The patient is positioned in lateral decubitus. The SLAP lesion is demonstrated by using a probe. Tissue elevator is inserted into the labral lesion to penetrate into the cyst wall. A soft anchor is placed. A birdbeak suture passer penetrates the posterior labrum. Then knot tying is done. The advantages of this single working portal technique are short operative time, a decreased risk of iatrogenic rotator cuff injury from accessory anterolateral portal or posterior labral injury from posterolateral portal, and avoiding unnecessary superior capsule incision for cyst exposure.

Reversal of Fatty Infiltration After Suprascapular Nerve Compression Release Is Dependent on UCP1 Expression in Mice.

In large rotator cuff tears, retraction of the supraspinatus muscle creates suprascapular nerve traction and compression. However, suprascapular nerve transection, when used in previous models, is different from chronic compression of the suprascapular nerve in patients. To define the role of suprascapular nerve chronic injury in rotator cuff muscle atrophy and fatty infiltration, we developed a novel reversible suprascapular nerve compression mouse model. We asked: (1) Can suprascapular nerve injury be induced by compression but reversed after compression release? (2) Can muscle fatty infiltration be induced by suprascapular nerve compression and reversed after compression release? (3) Is white fat browning involved in fatty infiltration resorption? Mice in a common strain of C57BL/6J were randomly assigned to suprascapular nerve transection (n = 10), nerve compression (n = 10), nerve compression and release (n = 10), or sham control (n = 10) groups. To study the role or white fat browning on muscle fatty infiltration, additional UCP1 reporter mice (n = 4 for nerve compression and n = 4 for nerve compression release) and knockout mice (n = 4 for nerve compression and n = 4 for nerve compression release) were used. Nerve injury was testified using osmium tetroxide staining and neural muscular junction staining and then semiquantified by counting the degenerating axons and disrupted junctions. Muscle fatty infiltration was evaluated using Oil Red O staining and then semiquantified by measuring the area fraction of fat. Immunofluorescent and Oil Red O staining on UCP1 transgenic mice was conducted to testify whether white fat browning was involved in fatty infiltration resorption. Ratios of UCP1 positively stained area and fat area to muscle cross-section area were measured to semiquantify UCP1 expression and fatty infiltration in muscle by blinded reviewers. Analysis of variance with Tukey post hoc comparisons was used for statistical analysis between groups. Suprascapular nerve injury was induced by compression but reversed after release. The ratios of degenerating axons were: sham control: 6% ± 3% (95% confidence interval [CI], 3%-10%); nerve compression: 58% ± 10% (95% CI, 45%-70% versus sham, p < 0.001); and nerve compression and release: 15% ± 9% (95% CI, 5%-26% versus sham, p = 0.050). The supraspinatus muscle percentage area of fatty infiltration increased after 6 weeks of nerve compression (19% ± 1%; 95% CI, 18%-20%; p < 0.001) but showed no difference after compression release for 6 weeks (5% ± 3%; 95% CI, 1%-10%; p = 0.054) compared with sham (2% ± 1%; 95% CI, 1%-3%). However, the fat area fraction in UCP1 knockout mice did not change after nerve compression release (6% ± 1%; 95% CI, 4%-8% at 2 weeks after compression and 5% ± 0.32%; 95% CI, 4%-6% after 2 weeks of release; p = 0.1095). We developed a clinically relevant, reversible suprascapular nerve compression mouse model. Fatty infiltration resorption after compression release was mediated through white fat browning. If the mechanism of browning of white fat in rotator cuff muscle fatty infiltration can be confirmed in humans, a UCP1 agonist may be an effective treatment for patients with suprascapular nerve injury.

Clinical treatment of suprascapular nerve compression syndromes via posterior portal by arthroscopic decompression of spinoglenoid notch cysts and release of suprascapular nerve

Objective To investigate the clinical outcomes of arthroscopic decompression of spinoglenoid notch cysts and release of suprascapular nerve in treating suprascapular nerve compression syndromes via posterior portal. Methods Eleven patients from January 2010 to January 2017 with spinoglenoid notch cysts complicated suprascapular nerve compression syndromes were included. There were 7 males and 4 females with the average age of 41.5±5.3 years old (range 29-56 years) with 3 patients left side involved and 8 right side. All patients were diagnosed with MRI and EMG. The surgical procedure began with posterior capsule arthroscopic releasement from the labrum, then found the spinoglenoid notch cyst. Split of the cyst was made for internal drainage, then found the suprascapular nerve and vessel bundle for clearing the bursal tissue with probe, decompressed the suprascapular nerve finally. Mecobalamin was taken (0.5 mg, tid) until 3 months postoperatively. The patients were evaluated by functional scores from American Shoulder Elbow Surgeons (ASES) and Constant-Murley preoperatively and postoperatively. Statistical analysis was conducted by student t-test. Results All patients were followed up at 7-15 months (with an average of 10 months). The mean preoperative ASES score increased from 46.5±3.7 to 93.8±2.2 at the time of final follow-up with the significant difference (t=3.359, P<0.05). Preoperative ASES score were good in 5 cases, fair in 4 cases and poor in 2 cases. The postoperative score were excellent in all patients. The Constant-Murley score was 47.3±4.2 preoperatively and 94.0±1.8 postoperatively with significant difference (t=4.776, P<0.05). Preoperative score were good in 6 cases and fair in 5 cases. The postoperative score were excellent in all patients. These patients had no recurrence of cyst after surgery and returned to work. Conclusion Arthroscopic decompression of spinlglenoid notch cyst and suprascapular nerve release via posterior portal can successfully treat suprascapular nerve compression syndrome resulting in spinoglenoid notch cyst. Key words: Shoulder; Arthroscopy; Cysts; Nerve compression syndromes

Arthroscopic management of suprascapular neuropathy of the shoulder improves pain and functional outcomes with minimal complication rates.

The purpose of this study was to systematically assess the arthroscopic management of suprascapular neuropathy, including the aetiology, surgical decision-making, clinical outcomes, and complications associated with the procedure. Three databases [PubMed, Ovid (Medline), and Embase] were searched. Systematic literature screening and data abstraction was performed in duplicate to present a review of studies reporting on arthroscopic management of suprascapular neuropathy. The quality of the included studies was assessed using level of evidence and the MINORS (Methodological Index for Nonrandomized Studies) checklist. In total, 40 studies (17 case reports, 20 case series, 2 retrospective comparative studies, and 1 prospective comparative study) were identified, including 259 patients (261 shoulders) treated arthroscopically for suprascapular neuropathy. The most common aetiology of suprascapular neuropathy was suprascapular nerve compression by a cyst at the spinoglenoid notch (42%), and the decision to pursue arthroscopic surgery was most commonly based on the results of clinical findings and investigations (47%). Overall, 97% of patients reported significant improvement in or complete resolution of their pre-operative symptoms (including pain, strength, and subjective function of the shoulder) over a mean follow-up period of 23.7months. Further, there was a low overall complication rate (4%) associated with the arthroscopic procedures. While most studies evaluating arthroscopic management of suprascapular neuropathy are uncontrolled studies with lower levels of evidence, results indicate that such management provides patients with significant improvements in pain, strength, and subjective function of the shoulder, and has a low incidence of complications. Patients managed arthroscopically for suprascapular neuropathy may expect significant improvements in pain, strength, and subjective function of the shoulder. Level IV, systematic review of level II to IV studies.

The Influence of Suprascapular Notch Shape on the Visualization of Structures in the Suprascapular Notch Region: Studies Based on a New Four-Stage Ultrasonographic Protocol.

Evaluation of the morphology of the suprascapular notch region is important from a clinical point of view because it is the most common site of suprascapular nerve compression and injury. A group of 120 patients underwent ultrasound examination of the suprascapular notch region according to our original four-stage “step-by-step” protocol. The notches were classified based on their morphology and measurements like maximal depth (MD) and superior transverse diameter (STD) as follows: type I-MD is longer than STD, type II-MD and STD are equal, type III-STD is longer than MD, and in type IV/V-notches only the bony margin was visualized without depression. Both suprascapular notches were fully visualized in 115 of 120 patients. The type III suprascapular notch was the most prevalent (64.2%), followed by type IV/V (18.7%), type I (11.1%), and type II (6.0%). Color Doppler analysis allowed the suprascapular artery to be recognized in all visualized notches. The suprascapular vein was visible in 176 notches and the suprascapular nerve in 150. Notches containing both suprascapular nerve and vein were significantly wider and shallower than average. As the suprascapular artery is the most easily recognised structure in the area, it may serve as a useful landmark of the suprascapular notch.

Are spinoglenoid ganglion cysts early markers of glenohumeral arthritis?

The objective of this study was to improve our understanding of the pathogenesis and symptoms of ganglion cysts (GCs) in the spinoglenoid notch. Two hypotheses were tested: (1) the labral tears responsible for these cysts are mainly degenerative and nontraumatic, (2) spinoglenoid cysts are early magnetic resonance image (MRI) markers of eccentric posterior glenoid wear. This was a descriptive diagnostic study. Patients were included when a spinoglenoid cyst was discovered after complaints of pain in the posterosuperior aspect of the shoulder. MRI and arthroscopy were used to classify the glenoid GC and characterize the glenohumeral joint. The GCs were classified into 1 of 3 types: GC0 (isolated cyst), GC1 (cyst and associated labral lesion), and GC2 (cyst and associated labral and cartilage lesion). Twenty patients (average age, 43 years) were included between 2000 and 2014. There were 7 GC0, 8 GC1, and 5 GC2 type cysts. Isolated labral tears (GC1) were always located posteriorly, without anterior extension or glenoid detachment. The humeral subluxation index was above 55% in 75% of shoulders, including all of the type GC2 shoulders. The 5 GC2 shoulders had type B1, B2, or C glenoids. The management of paraglenoid labral cysts must go beyond addressing the suprascapular nerve compression related to traumatic labral detachment, and surgeons should look automatically for associated degenerative joint damage. The diagnosis of GCs should be supplemented by humeral subluxation index measurement on computed tomography scan or MRI, and the patient should be informed that joint-related posterior shoulder pain might persist in cases of GC1 and GC2. Basic Science Study; Anatomy; Imaging and In Vivo.

Supraspinatus Unusual Atrophy Pattern: A Case Report

We present the case of an unusual atrophy pattern of the supraspinatus muscle subsequent to suprascapular nerve compression by a paralabral cyst located in the spinoglenoid notch. A 58-year-old right-handed manual female worker presented to a specialized shoulder consultation with severe progressive pain in her right shoulder. Clinical exam revealed isolated limitation in active abduction and a painful Jobe test. MR-arthrogram showed a 12 × 10 mm paralabral cyst consecutive to a superior labral anterior to posterior (SLAP) II lesion, associated with an isolated supraspinatus Thomazeau stage II atrophy and Goutallier stage II fatty infiltration. A rotator cuff tear was excluded. After a failed nonoperative management, the patient underwent arthroscopic cyst decompression, SLAP debridement and biceps tenodesis, and presented satisfactory pain relief at 12 months follow-up with a constant score of 76 points. A control MR-arthrogram showed no recurrence of the cyst with regression of atrophy to stage I. In addition to confirm the known association between SLAP lesions and paralabral cysts, and to support the debated reversibility of atrophy, this presented case reveals the existence of a new type of lesion induced by suprascapular nerve compression, consisting in isolated denervation of the supraspinatus muscle. This can be explained by an anatomic variation of the supraspinatus branch of the nerve which had an unusually distal origin, whereas typical compression patterns involve either supraspinatus and infraspinatus, or infraspinatus alone.

Clinical evaluation of the shape of the suprascapular notch--an ultrasonographic and computed tomography comparative study: Application to shoulder pain syndromes.

The most common site of suprascapular nerve compression and injury is the suprascapular notch. The aim of this study was to assess the sensitivity and specificity of sonography in determining the type of suprascapular notch (SSN). Thirty randomized patients (60 upper extremities) underwent USG examination of the shoulder area. The results were further compared with three-dimensional reconstructions of the scapulae obtained through CT examination to place the SSNs within a fivefold classification. For identification of type I, the sensitivity was 73.3% and the specificity 97.8%. For identification of type III, the values was 96.9% and 85.7%, respectively. Type II was not found in USG examination. Discrimination between type IV and V was not possible. The mean distance between the line connecting the edges of the SSN and the skin was 38 mm in right-handed patients and 34 mm in ambidextrous subjects. Ultrasonographic examination of the SSN is characterized by high specificity for type I, and high sensitivity for type III SSN. Discrimination between type IV and V of the SSN is not recommended based on sonographic evaluation.

Arthroscopic decompression of paralabral cyst around suprascapular notch causing suprascapular neuropathy.

A case of 22 year old male gymnast, who suffered from suprascapular neuropathy due to compression of suprascapular nerve by paralabral cysts around suprascapular notch, leading to marked atrophy of supraspinatus and infraspinatus muscles. After arthroscopic decompression of paralabral cysts, weakness and atrophy of the supraspinatus and infraspinatus muscles improved.

Double suprascapular foramina: an anatomical variation

Suprascapular notch transmit supra scapular nerve to the supraspinous fossa. Transverse scapular ligament bridges the notch to form a supra scapular foramen. This region is the most common location of supra scapular nerve injury & compression. Most important predisposing factor of supra scapular neuropathy is an ossified superior transverse scapular ligament. We report here a case of double supra scapular foramen found during our routine osteology demonstrations. The etiopathogenesis and clinical implications of such variations are discussed.

Spinoglenoid notch syndrome

Spinoglenoid notch syndrome is due compression of suprascapular nerve, due to a cyst, at the spinoglenoid notch causing pain, which is often mistaken for rotator cuff injury or cervical spondylosis. This patient presented with pain on the back of the right shoulder with weakness of external rotation and abduction. On examination, he had wasting, and weakness of the infraspinatus muscle and rest of the neurological examination was normal. His right shoulder magnetic resonance imaging scan revealed a cystic lesion at the spinoglenoid notch. An ultrasound guided aspiration of the cyst was done. He improved well with physiotherapy. One year later, the bulk and power of his infraspinatus muscle was normal.

Morfometrical and morphological analysis of the suprascapular notch with multidetector computerized tomography

IntroductionSuprascapular notch is situated in lateral section of margo superior of scapula as adjacent to substratum of processus coracoideus. Suprascapular nerve compression is characterized with chronic localized pain spreading to shoulder posterior and/or lateral areas, to under brachion and into the neck; and with weakness in shoulder abduction, and also atrophy of supraspinatus and infraspinatus muscles. In our study, we aimed to exhibit notch suprascapularis morphology and the variations of this structure which creates an important passage for suprascapular nerve. MethodsThis study was conducted on 100 patients (35 females–65 males). Average age of individuals included into the study was 17–87 years. ResultsThe morphological study of the suprascapular notch revealed six different types of notches. DiscussionThe data we have obtained in our study are important to constitute a reference space of Turkish society. Furthermore, the fact that the differences between genders and right-left are exhibited will be helpful for surgeons who perform surgery in this region. Therefore, we conclude that the exhibited results will provide a better detail of information regarding morphometry of suprascapular notch and will aid in diagnosing and surgical treatment for shoulder pain.

Subclavius posticus: an anomalous muscle in association with suprascapular nerve compression in an athlete.

Subclavius posticus is a rare anomalous muscle that traverses from the costal cartilage of the first rib posterolaterally to the superior border of the scapula. We present an athlete who presented with incapacitating suprascapular nerve compression associated with a subclavius posticus diagnosed by MRI. Symptoms were relieved, and function was restored by decompression of the nerve and excision of the anomalous muscle. We present this case to bring awareness of the subclavius posticus as an anatomic variant and a potential additional source for compression in suprascapular neuropathy. We recommend high-resolution magnetic resonance imaging to evaluate cases of isolated suprascapular neuropathy. V.