Spinoglenoid Ligament Research Articles

ДИНАМИЧЕСКАЯ НЕВРОПАТИЯ НАДЛОПАТОЧНОГО НЕРВА – «БОЛЬ В ЛОПАТКЕ И ПЛЕЧЕ». МАНУАЛЬНАЯ ДИАГНОСТИКА И ЛЕЧЕНИЕ

Dynamic suprascapular nerve neuropathy is a cause of shoulder pain and weakness that is often overlooked. The difficulty in diagnosing the nerve dynamic damages is conditioned by the fact that the symptoms are provoked by physical exertion(s) or a certain position of the limb due to compression and(or) overstretching as well as violations of the longitudinal and transverse sliding of the nerve. These symptoms subside when the provoking factor ceases to act and return when movements repeat. Neurologic examinations and nerve conduction studies performed at rest usually show no change. The suprascapular nerve dysfunction is closely related to rotator cuff pathology. The nerve damage is often caused by a dynamic microtrauma during repetitive arm movements over the head with maximum deflection and external rotation of the arm. Suprascapular neuropathy can be caused by the nerve compression or traction in the suprascapular notch or spinoglenoid region. The nerve damage in the suprascapular notch causes weakness in both the supraspinatus and infraspinatus muscles, while damage under the spinoglenoid ligament affects only the infraspinatus muscle. Diagnostics should include manual testing of the supraspinatus and infraspinatus muscles with a neutral position of the arm and neck of the patient being examined and during provocative neurodynamic tests of stretching the suprascapular nerve. Therapeutic measures should be directed to all interdependent components of the peripheral nervous system in the following sequence: osteopathic treatment of the nerve trunk interface (tissues surrounding the nerve trunk); osteopathic treatment of the innervated tissue; osteopathic treatment of the connective tissue of the suprascapular nerve.

Posterior Shoulder Pain and Arthroscopic Decompression of the Suprascapular Nerve at the Spinoglenoid Notch

Suprascapular nerve compression is a disease entity not easily recognized or well understood by many surgeons. Posterior shoulder pain, muscle weakness, and muscle atrophy can result from compression of the nerve at either the transverse scapular ligament or the spinoglenoid ligament in many young adults. Compression at the spinoglenoid ligament, although thought to be rare, is often the result of repetitive overhead activities in either athletes or laborers and results in weakness and atrophy of the infraspinatus muscle. More recently, compression at this site occurs in patients with a massive rotator cuff tear. While this diagnosis is complex and other diagnoses must be considered and ruled out, early intervention is important to successfully manage this patient and return them to their desired activities to avoid permanent muscle atrophy. This paper will discuss the detailed physical examination, adjunct diagnostic procedures, and appropriate arthroscopic surgical treatment of this disease entity to provide the expected outcome with great satisfaction.

Posterior Shoulder Pain and Arthroscopic Decompression of the Suprascapular Nerve at the Transverse Scapular Ligament

The etiology of posterior shoulder pain can be elusive for the treating physician. Compression of the suprascapular nerve at either the transverse scapular ligament or the spinoglenoid ligament can lead to resultant posterior shoulder pain, muscle weakness, and permanent muscle atrophy. Compression at the transverse scapular ligament, the more common finding than realized in the past in patients, can often result in weakness and atrophy of both the supraspinatus and infraspinatus muscles as compression occurs at the suprascapular notch prior to the nerve giving off motor branches to each of these muscles. Patients with this pathology often have a long-standing disease course of missed diagnoses and even wrong surgical procedures. This paper will discuss the anatomy, pathophysiology, and presentation of symptoms in patients. A thorough discussion of the physical examination as well as appropriate adjunct diagnostic procedures will follow to aid the clinician in making a correct diagnosis with detailed recommendations for appropriate arthroscopic decompression allowing the athlete and patient to return to activities of daily living with a short recuperation period.

Morphological study of the inferior transverse scapular ligament

The suprascapular nerve can be compressed by the inferior transverse scapular ligament (ITSL), also known as the spinoglenoid ligament, and this entrapment results in dysfunction of the external rotation of the upper arm owing to isolated weakness of the infraspinatus muscle. The morphology of the ITSL has not been adequately characterized. The aim of this study was to clarify the morphological characteristics of the ITSL. In total, 110 shoulders from 72 cadavers were dissected in this study. The ITSL was present in 73 (66.4%) of the 110 specimens, and comprised membrane in 40 (36.4%), ligament in 25 (22.7%), and both membrane and ligament in eight (7.3%). This structure could be classified into three types on the basis of its shape: band-like (33.6%, type I), triangular (15.5%, type II), or irregular (17.3%, type III). In the spinoglenoid notch, the suprascapular nerve was always close to the lateral margin of the scapular spine. The length of the ligament between its origin and insertion sites ranged from 8.7 to 23.4 mm at its superior margin and from 8.9 to 17.5 mm at its inferior margin. The ligament width and thickness at its midportion ranged from 1.6 to 10.0 mm and from 0.1 to 1.2 mm, respectively. The results of this study improve understanding of the ITSL and will be helpful for successful diagnoses and treatments for selective suprascapular nerve entrapment.

Das spinoglenoidale Ligament – eine anatomische Studie

In over-head motion athletes a dysfunction of the suprascapular nerve has been described. In the literature a relation between the spinoglenoid ligament and the dysfunction of the suprascapular nerve is mentioned. An appreciable variability of this ligament is described. The purpose of the present study was the anatomic documentation of the spinoglenoid ligament and its relation to the suprascapular nerve. In 36 shoulder specimen the suprascapular nerve, the spinoglenoid and bony parameter of the scapula were documented. The statistic evaluation was performed with SPSS12.0. In all but one specimen a spinoglenoid ligament was present. In 20 cases (56 %) the infraspinatus muscle inserted at the spinoglenoid ligament. In five cases (14 %) the spinoglenoid ligament reached the glenohumeral joint capsule. In two cases the suprascapular nerve was completely fixed with the ligament, in four cases the perineural soft tissue had a close connection to the ligament. In four cases a branch of the nerve passed through the ligament. All together in 28 % of the specimen there were mechanical conflicts. In one case a ganglion compressed the nerve. Our anatomic study showed in a significant number of cases a possible entrapment of different origins. These findings have implications both for diagnostics and treatment.

Paper # 27: Endoscopic Release of the Spinoglenoid Ligament: A Safe and Efficacious Alternative to an Open Approach

Paper # 27: Endoscopic Release of the Spinoglenoid Ligament: A Safe and Efficacious Alternative to an Open Approach

Anatomical basis of the suprascapular nerve entrapment, and clinical relevance of the supraspinatus fascia

The entrapment of the suprascapular nerve (SSN) is commonly considered at the level of the suprascapular notch and more rarely in the spinoglenoid notch. Recent per-operative findings showed a compression of the SSN along its course in the supraspinatus fossa. The removal of a fascia for releasing the nerve between the suprascapular notch and spinoglenoid notch led us to purchase an anatomical study. 30 cadaver shoulders have been dissected. The morphological features about the suprascapular notch, the supraspinatus fascia, and the spinoglenoid notch have been observed. Histological studies of the fascia and the spinoglenoid ligament have been performed. Morphometric parameters such as shape of the suprascapular notch, diameters of the SSN before and after the suprascapular notch, distance between the two notches, length of the course of the SSN into the supraspinatus fossa, diameters of the spinoglenoid notch have been measured. The shape of the suprascapular notch could be seen as "U"- or "V" as previously reported. The fascia was quite constant (completely identified in 29 shoulders) and was the lateral extension of the supraspinatus fascia. The SSN coursed between the bone and the fascia and was surrounded by fat tissue. This fascia was thickened at the level of the spinoglenoid notch and joined the infraspinatus fascia. The spinoglenoid ligament was seen in 28 shoulders. In pathologic and post-trauma conditions, the fascia can be retracted or thickened and the SSN may be entrapped along its course in the supraspinatus fossa, between the suprascapular notch and the spinoglenoid notch and without any compression in any notch. These anatomical data lead us to consider that a tunnel syndrome may concern the SSN.

Posterior Shoulder Pain: A Dynamic Study of the Spinoglenoid Ligament and Treatment With Arthroscopic Release of the Scapular Tunnel

The purpose of this study was to determine the pressure exerted on the suprascapular nerve by compression of the spinoglenoid ligament during glenohumeral range of motion. In addition, a 2-portal technique was described to arthroscopically visualize and safely release the spinoglenoid ligament while visualizing the suprascapular nerve, artery, and vein. Ten cadaveric shoulders were used for visual observation of variation in the position and tension of the spinoglenoid ligament. In 15 additional shoulders, a transducer was used to sense the pressure changes and was recorded in voltage. Pressure changes created by the spinoglenoid ligament on the distal suprascapular nerve in the scapular tunnel during glenohumeral motion were recorded. Internal rotation, rather than external rotation, in any position of the shoulder created a visual increase of tension in the spinoglenoid ligament. Increased pressure readings were noted with internal rotation and with 90 degrees of abduction, full abduction, and full adduction of the shoulder. The suprascapular nerve occupying the space created by the spinoglenoid ligament experiences an increased pressure during glenohumeral range of motion and positions that mimic overhead throwing. The dynamic nature of the ligament with its insertion on the posterior capsule required a new minimally invasive technique for its release that can be safe and straightforward. The spinoglenoid ligament was affected by the position of the glenohumeral joint. These changes in pressure in combination with repetitive shoulder movement are likely components that cause repeated trauma or compression on the distal suprascapular nerve created by a scapular tunnel syndrome. The surgical technique provides a treatment option when conservative treatment fails in the patient with posterior shoulder pain. The spinoglenoid ligament was affected by the position of the shoulder, with the most pressure noted with the arm in full adduction and internal rotation. This pressure can be treated with arthroscopic release.

33

Purpose: Spinoglenoid ligament entrapment of the suprascapular nerve presents with acute onset of deep, diffuse, posterolateral shoulder pain. Patients demonstrate consistent findings of pain with palpation over the suprascapular notch, spinati muscle atrophy, or isolated infraspinatus muscle atrophy often secondary to a ganglion at the spinoglenoid notch. The current trend is toward early surgical decompression through an open posterior approach. The purpose of this study was to determine the outcome following endoscopic release of the spinoglenoid ligament, in treatment of suprascapular nerve entrapment syndromes (SNES). Methods: Between 1/1998 and 3/2006, 16 patients presented with posterior shoulder pain, presumed to have SNES. Diagnosis was determined by physical exam, and confirmed by MRI and EMG/NCV studies. The average patient age was 39 (range 23 to 69). There were 6 males and 10 females. All patients had limited use of their shoulder prior to surgery. All patients underwent endoscopic spinoglenoid ligament release performed by one surgeon, in the beach chair position using standard posterior, lateral, and accessory portals as needed. Pre-operative and post-operative ASES score, shoulder pain, strength, and ROM were documented. A paired sample t-test was applied to preoperative and postoperative measurements which were continuous variables. Results: Four patients were excluded from the study secondary to concomitant open supraspinatus medial wedge resection. At 4 years average follow-up (range 1 to 8 years), 11 of the 12 (94%) remaining patients had relief of their shoulder pain. All had full range of motion, and improvement in ASES score (p<0.05). All patients returned to full activities of daily living. The average time of return to full function was 6 months. No nerve or vascular complications were noted. Seven of the patients did not have full return of function of the infraspinatus; however these patients had significantly longer time from injury to surgery. No patient required open decompression of the spinoglenoid notch. Conclusions: Entrapment of the suprascapular nerve by the spinoglenoid ligament can be a common cause of posterior shoulder pain. This simple minimally invasive technique of endoscopic release of the spinoglenoid ligament can provide for patients symptomatic relief and allow them to return to function faster and with less complications than traditional open posterior release. Early treatment is recommended to improve return of function of the infraspinatus. If noted, the author indicates something of value received. The codes are identified as follows: a, research or institutional support; b, miscellaneous funding; c, royalties; d, stock options; e, consultant or employee. *The Food and Drug Administration has not cleared the drug and/or medical device for the use described in this presentation (ie, the drug or medical device is being discussed for an “off-label” use). If noted, the author indicates something of value received. The codes are identified as follows: a, research or institutional support; b, miscellaneous funding; c, royalties; d, stock options; e, consultant or employee. *The Food and Drug Administration has not cleared the drug and/or medical device for the use described in this presentation (ie, the drug or medical device is being discussed for an “off-label” use).

THE SPINOGLENOID LIGAMENT

Background: Dysfunction of the distal branch of the suprascapular nerve has been reported in athletes involved in throwing or overhead sports. The consistent presence of a dynamic anatomic structure, the spinoglenoid ligament, overlying the nerve in the spinoglenoid notch may be a contributing factor to the dysfunction of this nerve. The purpose of this study was to report the anatomy, morphology, and histological characteristics of the spinoglenoid ligament. Methods: The spinoglenoid ligaments of fifty-eight fresh-frozen cadaver shoulders were dissected to evaluate their anatomic dimensions, histological characteristics, and relationship to the suprascapular nerve, the posterior part of the capsule, and the glenoid rim. The spinoglenoid ligament was harvested, with its insertions on the scapular spine and on the capsule and glenoid left intact, for the histological analysis. Results: Dissection revealed that a spinoglenoid ligament was present in all specimens. The ligament was found to form an irregular quadrangular shape. On gross examination, the deep fibers of the ligament extended from the lateral aspect of the scapular spine to the posterior part of the glenoid and the superficial fibers blended with the posterior aspect of the shoulder capsule. Histological sections demonstrated Sharpey fibers inserting into bone at the scapular spine and blending with the posterior aspect of the shoulder capsule to insert into the posterior surface of the glenoid, findings that confirmed the ligamentous nature of this structure. Conclusions: This study revealed the presence of the spinoglenoid ligament in all of the shoulders that were examined, with some variation in the size of the ligament. Clinical Relevance: In this study, we identified a complex, multilayer, distinct spinoglenoid ligament with superficial and deep attachments to the glenoid. These findings support a possible relationship between this ligament and entrapment neuropathy of the distal suprascapular nerve.

The Spinoglenoid Ligament

Dysfunction of the distal branch of the suprascapular nerve has been reported in athletes involved in throwing or overhead sports. The consistent presence of a dynamic anatomic structure, the spinoglenoid ligament, overlying the nerve in the spinoglenoid notch may be a contributing factor to the dysfunction of this nerve. The purpose of this study was to report the anatomy, morphology, and histological characteristics of the spinoglenoid ligament. The spinoglenoid ligaments of fifty-eight fresh-frozen cadaver shoulders were dissected to evaluate their anatomic dimensions, histological characteristics, and relationship to the suprascapular nerve, the posterior part of the capsule, and the glenoid rim. The spinoglenoid ligament was harvested, with its insertions on the scapular spine and on the capsule and glenoid left intact, for the histological analysis. Dissection revealed that a spinoglenoid ligament was present in all specimens. The ligament was found to form an irregular quadrangular shape. On gross examination, the deep fibers of the ligament extended from the lateral aspect of the scapular spine to the posterior part of the glenoid and the superficial fibers blended with the posterior aspect of the shoulder capsule. Histological sections demonstrated Sharpey fibers inserting into bone at the scapular spine and blending with the posterior aspect of the shoulder capsule to insert into the posterior surface of the glenoid, findings that confirmed the ligamentous nature of this structure. This study revealed the presence of the spinoglenoid ligament in all of the shoulders that were examined, with some variation in the size of the ligament.

The spinoglenoid ligament: an anatomic study.

The spinoglenoid ligament and its anatomic variations are described in 27 shoulders from 15 cadavers. In each shoulder one or two distinct spinoglenoid ligaments originated from the base of the spine of the scapula; they inserted on the neck of the scapula or the shoulder joint capsule. In the 19 shoulders in which only one spinoglenoid ligament was present, it inserted into the neck of the scapula in 14 cases and into the shoulder joint capsule in five instances. In the eight shoulders in which there were two ligaments, one inserted into the neck of the scapula and the other into the shoulder joint capsule. We did not observe any hypertrophic spinoglenoid ligaments that may have compressed the suprascapular nerve.

Spinoglenoid septum: a new anatomic finding

The spinoglenoid ligament has been implicated in compression of the suprascapular nerve in cases with isolated atrophy of the infraspinatus muscle. We dissected 32 shoulders of 16 embalmed cadavers. We could detect a spinoglenoid ligament in only 5 shoulders, and it was thin, loose, and weak. Instead of the spinoglenoid ligament, we observed a septum formed by the thickening of the fascial cover of the distal third of the supraspinatus and infraspinatus muscles. It originated from the spinoglenoid notch and extended into the posterior capsule. We named this structure the spinoglenoid septum. The suprascapular nerve passed between the bony margin of the spinoglenoid notch and the medial concave margin of the spinoglenoid septum. This septum may be a cause of dynamic compression of the suprascapular nerve.

Paper #102 Richard Caspari award finalist: Spinoglenoid ligament: anatomy, morphology, histology with clinical correlations

To report 100 percent prevalence of the spinoglenoid ligament, the anatomy, morphology and histology of the ligament. Secondly, this dynamic structure is involved in causing repetitive trauma to the branch of the suprascapular nerve supplying the infraspinatus muscle. Dysfunction of the distal suprascapular nerve is reported in athletes involved in throwing and overhead sports. No study has been done to evaluate the dynamics of the space, created by the spinoglenoid ligament and occupied by the suprascapular nerve. Documenting a pressure change in this compartment and the relationship to shoulder position gives valuable information to the possible etiology of infraspinatus muscle atrophy and formation of ganglion cyst. The last part of this study is to verify the safety of performing arthroscopic release of the spinoglenoid ligament through the newly described technique.

Does the inferior transverse scapular ligament cause distal suprascapular nerve entrapment? An anatomic and morphologic study

The number of reports on entrapment of the distal suprascapular nerve is increasing, but the incidence with regard to the inferior transverse scapular ligament remains controversial. Therefore, we investigated its incidence and anatomy in a series of cadaveric specimens; 115 shoulders (62 cadavers) were examined. The ligament was classified as either ligament- or membrane-type depending on its thickness. The width of the ligament and its maximal distance to bone and nerve were measured. Among the 115 specimens, the ligament was absent in 21 cases (18.3%), the ligament-type was present in 25 (21.7%), and the membrane-type was present in 69 (60.0%). The ligament width varied from 1.8 to 9.0 mm (mean, 5.4 mm), the maximal distance from ligament to bone varied from 3.0 to 11.1 mm (mean, 5.7 mm), and the distance from ligament to nerve was from 0.1 to 7.0 mm (mean, 3.1 mm). As there was considerable variation in the distances from the ligament to bone and nerve, the ligament may play a role in paralysis of the infraspinatus muscle, depending on these distances.

Anatomical basics, variations, and degenerative changes of the shoulder joint and shoulder girdle

This paper summarizes the anatomical basics of the shoulder, their variations, and precise definitions, including differential diagnoses. It also describes the characteristic degenerative changes caused by aging. A typical variation (7–15%) is the os acromiale, which forms the triangular epiphysis of the scapular spine. This abnormality must be differentiated from a fracture of the acromion or a pseudarthrosis. Because ossification of the acromion is complete after age 25, the os acromiale should be diagnosed only after this age. The shape of the acromion is a further important feature. In a recent anatomical study, the following frequencies of the Bigliani-types of the acromial shape were anatomically determined — type 1 (flat), 10.2% and type 2 (curved), 89.8%. Type 3 (hooked) was not observed, which indicates that this type is probably a misinterpretation of the so-called acromial spur. Minor dehiscences and perforations in the infraspinate or supraspinate fossa should not be confused with malignant osteolyses. The scapula has three ligaments of its own, (1) the coracoacromial ligament and its osseous fixations form an osteofibrous arch above the shoulder joint, which plays a part in impingement syndrome; (2) the superior transverse scapular ligament or its ossified correlate arches the scapular incisure and can cause a typical compression syndrome of the suprascapular nerve; (3) the inferior transverse scapular ligament is of no great clinical importance. Two intraarticular structures (glenoid labrum and tendon of the long bicipital head) must be mentioned. The glenoid labrum consists of dense connective tissue and surrounds the margin of the glenoid cavity. Two areas exhibit specialized conditions, cranial at the supraglenoid tubercle an intimate relationship exists to the tendon of the long bicipital head and in about 55% of cases, the labrum is stretched over the glenoid rim at the ventral side. At the area of the biceps-tendon-labrum complex, so-called SLAP-lesions may occur and at the glenoid rim, where the labrum is often not fixed to the bony margin, avulsions of the labrum may occur. This well-established anatomical condition must not be mistaken for a manifest Bankart-lesion. The glenohumeral ligaments, which are located in the ventral articular capsule, have a stabilizing function for the ventral part of the glenoid labrum. The glenohumeral ligaments lift the articular lip where it crosses the glenoid notch. This ‘labrum-lift effect’ supports the stabilizing features of the articular lip and the glenohumeral ligaments. The rotator cuff is composed of the tendons of the teres minor, infraspinatus, supraspinatus, and subscapularis muscles. This cuff has a poorly vascularized area, due to mechanical conditions, about 1.5 cm from the major tubercle, which causes degenerative changes and eventually may lead to ruptures. Results of the impingement-syndrome and the osteoarthrotic changes of the shoulder and acromioclavicular joint are also presented and discussed. Finally, the coracoclavicular joint, which probably represents no congenital entity but appears due to a changed, lowered position of the shoulder girdle, is discussed. The paper also presents instructive figures of anatomical preparations that can be used to make more precise radiological and differential diagnoses. All preparations were done by the author and are part of a series of more than 300 preparations of the shoulder joint and girdle.

Suprascapular neuropathy.

Suprascapular neuropathy is an uncommon cause of shoulder pain and weakness and therefore may be overlooked as an etiologic factor. The suprascapular nerve is vulnerable to compression at the suprascapular notch as well as at the spinoglenoid notch. Other causes of suprascapular neuropathy include traction injury at the level of the transverse scapular ligament or the spinoglenoid ligament and direct trauma to the nerve. Sports involving overhead motion, such as tennis, swimming, and weight lifting, may result in traction injury to the suprascapular nerve, leading to dysfunction. The diagnosis of suprascapular neuropathy is based on clinical findings and abnormal electrodiagnostic test results, after the exclusion of other causes of shoulder pain and weakness. Magnetic resonance imaging may provide an anatomic demonstration of nerve entrapment and muscle atrophy. With this modality, ganglion cysts are recognized with increasing frequency as a source of external compression of the suprascapular nerve. Without evidence of a discrete lesion compressing the nerve, nonoperative treatment should include physical therapy and avoidance of precipitating activities. When nonoperative treatment fails to alleviate symptoms or when a discrete lesion such as a ganglion cyst is present, surgical decompression is warranted. Decompression gives reliable pain relief, but recovery of shoulder function and restoration of atrophied muscle tissue may be incomplete.

Anatomy and histological characteristics of the spinoglenoid ligament.

The spinoglenoid (inferior transverse scapular) ligament, when present, is located at the spinoglenoid notch. The ligament originates on the spine of the scapula and inserts on the superior margin of the glenoid neck. Because of discrepancies in the literature, we sought to determine its prevalence and to define its histological characteristics. We dissected 112 shoulders of seventy-six cadavera and classified the ligament as absent or an insubstantial structure, a thin fibrous band (type I), or a distinct ligament (type II). We found no distinct ligamentous structure in twenty-two shoulders (20 percent), a type-I ligament in sixty-eight shoulders (61 percent), and a type-II ligament in twenty-two shoulders (20 percent). Overall, ninety (80 percent) of the shoulders had a fibrous band of tissue that, together with the spine of the scapula, formed a narrow fibro-osseous tunnel through which the suprascapular nerve traveled. The bone-spinoglenoid ligament-bone complexes from three specimens were analyzed histologically. There were two type-I ligaments and one type-II ligament; all three ligaments were composed of collagen fibers. One type-I ligament and the type-II ligament demonstrated Sharpey fibers at their origin on the spine of the scapula. The other type-I ligament attached to the spine of the scapula through the periosteum. All three ligaments inserted into the periosteum of the glenoid neck.

The incidence of ganglion cysts and other variations in anatomy along the course of the suprascapular nerve

When the diagnosis of suprascapular nerve entrapment syndrome is being considered, variations in anatomy are possible etiologic factors. Seventy-nine shoulders from 41 cadavers were examined for anatomic variations and for ganglion cyst formation in the suprascapular notch, superior transyerse scapular ligament, and inferior transverse scapular ligament. The morphologic evaluation of the suprascapular notch revealed a “U” shape in 77% and a “V” shape in 23%, with 89% of cadavers having the same notch shape bilaterally. In 23% of shoulders a variation of the superior transverse scapular ligament was demonstrated such as partial and complete ossification and multiple bands including the first report of a trifid superior transverse scapular ligament. An inferior transverse scapular ligament was observed in only 14% of shoulders. One ganglion cyst was identified, for an incidence of 1%. The mass was located in the supraspinatus fossa adjacent to the superior transverse scapular ligament and appeared to compress and alter the course of the suprascapular nerve. When operative treatment is elected for suprascapular nerve entrapment syndrome and an open surgical approach is undertaken, the location and source of disease and morphologic and anatomic variants must be recognized to ensure adequate access and complete decompression of the suprascapular nerve. The classical description of the superior transverse scapular ligament as a completely nonossified single band should be expected, on average, in approximately three fourths of the cases. Partial or complete ossification and anomalous bands of the superior transverse scapular ligament or a ganglion cyst along the course of the suprascapular nerve may be encountered. Although a superior transverse scapular ligament should be anticipated in all shoulders, an inferior transverse scapular ligament will be a much less frequent finding. The role and significance of suprascapular notch morphologic characteristics warrant further investigation.

Suprascapular nerve rotator cuff compression syndrome in volleyball players

Selective denervation of the infraspinatus muscle producing weakness and wasting has been reported in certain sports (eg, volleyball and baseball). Nerve kinking or friction caused by excessive infraspinatus motion and compression by superior or inferior transverse scapular ligament or ganglions have been proposed as possible causes. However, in extreme abduction with full external rotation of the shoulder, the medial tendinous margin between the infraspinatus and supraspinatus muscles impinges strongly against the lateral edge of scapular spine, compressing the intervening infraspinatus branch of the suprascapular nerve. Spinoglenoid notchplasty has been performed in 5 elite volleyball players with infraspinatus neuropathy, allowing recovery of shoulder function in all patients and correction of infraspinatus muscle wasting. All returned to the same or higher level of volleyball by 8 months after surgery. An alternative cause of infraspinatus compromise in volleyball players is proposed and has been treated surgically with satisfactory outcome.