Morphological and radiological study of ossified superior transverse scapular ligament as potential risk factor of suprascapular nerve entrapment

Correlation of suprascapular notch morphology with suprascapular nerve palsy: a 3D-computed tomography study

Background

The morphology of the suprascapular (SS) notch is a very important factor in treatment of suprascapular nerve (SSN) palsy. Several studies have reported SS notch morphology in cadavers or using a three-dimensional computed tomography (3D-CT); however, none has reported the distribution of SS notch morphology according to the age group. In addition, the correlation between SS notch morphology and SSN palsy remains unclear. The purposes of this study were to investigate the morphological distribution of the SS notch by age group in a large population and to assess the relationship between SS notch morphology and SSN palsy.

Methods

We studied the 3D-CT images of 1063 shoulders in 1009 patients (mean age, 60.8 years; age range, 14-96 years). There were 53 shoulders with SSN palsy and 1010 shoulders without SSN palsy. Morphology of the SS notch was classified by Rengachary's classification (types I-VI). Shoulders with types I-IV were classified into the nonossified superior transverse scapular ligament (STSL) group (group N) and those with types V and VI into the ossified STSL group (group O).

Results

The Rengachary's classifications of the 1063 shoulders were as follows: type I: n = 113, 10.6%; type II: n = 313, 29.4%; type III: n = 383, 36.0%; type IV: n = 109, 10.3%; type V: n = 107, 10.0%; and type VI: n = 38, 3.6%. Mean age was significantly older in the ossified STSL group, and the age was <40 years for only two shoulders in this group. The Rengachary's classifications of the SSN palsy cases were as follows: type I: 7.5%, II: 24.5%, III: 34.0%, IV: 15.1%, V: 13.2%, and VI: 5.7%. There was no statistical difference in age and sex, Rengachary type, or ossification between SSN palsy and non-SSN palsy cases.

Conclusions

Ossification of the STSL was significantly more common in older patients, which suggests age-related change. In addition, no relation was identified between narrow notch or ossification of the STSL with the onset of SSN palsy.

Accuracy of suprascapular notch cross-sectional area by MRI in the diagnosis of suprascapular nerve entrapment syndrome: a retrospective pilot study

BACKGROUND

Previous studies have demonstrated that morphological changes in the suprascapular notch are closely associated with suprascapular nerve entrapment syndrome (SNES). Thus, we hypothesized that the suprascapular notch cross-sectional area (SSNCSA) could be a good diagnostic parameter to assess SNES.

METHODS

We acquired suprascapular notch data from 10 patients with SNES and 10 healthy individuals who had undergone shoulder magnetic resonance imaging (S-MRI) and had no evidence of SNES. T2-weighted coronal magnetic resonance images were acquired from the shoulder. We analyzed the SSNCSA at the shoulder on S-MRI using our image-analysis program (INFINITT PACS). The SSNCSA was measured as the suprascapular notch, which was the most affected site in coronal S-MRI images.

RESULTS

The mean SSNCSA was 64.50 ± 8.93 mm2 in the control group and 44.94 ± 10.40 mm2 in the SNES group. Patients with SNES had significantly lower SSNCSA (P < 0.01) than those in the control group. Receiver operating curve analysis showed that the best cut-off of the SSNCSA was 57.49 mm2, with 80.0% sensitivity, 80.0% specificity, and an area under the curve of 0.92 (95% CI [0.79, 1.00]).

CONCLUSIONS

The SSNCSA was found to have acceptable diagnostic properties for detecting SNES. We hope that these results will help diagnose SNES objectively.

Outcomes after minimally invasive and surgical management of suprascapular nerve entrapment: A systematic review

Background

The prevalence of suprascapular neuropathy is higher than previously estimated. Recent literature highlights a myriad of treatment options for patients ranging from conservative treatment and minimally invasive options to surgical management. However, there are no comprehensive review articles comparing these treatment modalities.

Objective

The purpose of this review article is to summarize the current state of knowledge on suprascapular nerve entrapment and to compare minimally invasive treatments to surgical treatments.

Methods

The literature search was performed in Mendeley. Search fields were varied redundant. All articles were screened by title and abstract and a preliminary decision to include an article was made. A full-text screening was performed on the selected articles. Any question regarding the inclusion of an article was discussed by 3 authors until an agreement was reached.

Results

Recent studies have further elucidated the pathoanatomy and described several risk factors for entrapment ranging. Four studies met our inclusion criteria regarding peripheral nerve stimulation with good pain and clinical outcomes. Two studies met our inclusion criteria regarding pulsed radiofrequency and showed promising pain and clinical outcomes. One study met our inclusion criteria regarding transcutaneous electrical nerve stimulation and showed good results that were equivalent to pulsed radiofrequency. Surgical treatment has shifted to become nearly all arthroscopic and surgical outcomes remain higher than minimally invasive treatments.

Conclusions

Many recently elucidated anatomical factors predispose to entrapment. A history of overhead sports or known rotator cuff disease can heighten a clinician’s suspicion. Entrapment at the suprascapular notch is more common overall, yet young athletes may be predisposed to isolated spinoglenoid notch entrapment. Pulsed radiofrequency, peripheral nerve stimulation, and transcutaneous electrical nerve stimulation may be effective in treating patients with suprascapular nerve entrapment. Arthroscopic treatment remains the gold-standard in patients with refractory entrapment symptoms.

Bilateral suprascapular notches are asymmetrically shaped in a third of the Asian population

PURPOSE

The side-to-side differences within an individual's suprascapular notch (SSN) and the clinical characteristics of an ossified superior transverse scapular ligament are unclear. Therefore, the morphological asymmetry of the SSN was investigated, and the factors associated with the ossification of the superior transverse scapular ligament were analyzed.

METHODS

Two hundred and seventy-six computed tomography images were retrospectively analyzed, which included those of both scapulae of Asian patients (mean age, 62.1 ± 19.1 years; males, 197) with high-energy injuries or respiratory diseases. Variations in the SSN were classified into six types based on Rengachary's classification using reconstructed three-dimensional computed tomography. The group with a type VI SSN (completely ossified superior transverse scapular ligament) in at least one scapula was compared with the other group for age, sex, and chronic comorbidities.

RESULTS

Among 276 patients, 95 (34.4%) had asymmetric SSNs and 15 (5.4%) had type VI SSNs. There were no significant differences in age, sex, or comorbidities between both the groups. However, on comparing age groups, the prevalence of type VI SSN was higher in patients aged > 70 years than in those aged < 70 years. Fifteen patients had type VI SSNs, which were unilateral in 10 patients.

CONCLUSION

Asymmetric SSNs were observed in a third of the Asian patients. There were variations in SSNs between individuals and also within an individual. In the cases with suprascapular nerve paralysis, the difference in SSN morphology compared to a healthy side should be considered.

LEVEL OF EVIDENCE

III.

The morphological stenosis pattern of the suprascapular notch is revealed yielding higher incidence in the discrete type and elucidating the inevitability of osteoplasty in horizontally oriented stenosis

PURPOSE

To identify the morphological patterns of suprascapular notch stenosis.

METHODS

Suprascapular notch space capacity was assessed by morphometric analysis of 333 dry scapulae. Suprascapular notch parameters-superior transverse distance, middle width, depth, medial border length and lateral border length-were measured. The probable suprascapular notch stenosis was referenced by (1) comparing each obtained parameter measurement to the range of the suprascapular nerve diameter, and (2) quantifying the reduced parameters. Finally, the morphological pattern was determined based on the collective reduction of the parameters and their alignments.

RESULTS

Five types of suprascapular notch based on depth to superior transverse distance ratio were identified and assessed. Type-I showed low incidence of stenosis (6/333) and low frequency within type (6/28) with potential risk of horizontal compression. Type-II showed relatively low incidence of stenosis (9/333) and low frequency within type (9/50) with undetermined pattern. Type-III showed relatively higher incidence of stenosis (47/333) but low frequency within type (47/158) with potential risk of vertical compression. Type-IV (foramen) showed low incidence of stenosis (6/333) and relatively lower frequency within type (6/26) with potential risk of encircled compression. Finally, type-V (discrete) showed relatively high incidence of stenosis (40/333) and high frequency within type (40/71) with potential risk of vertical compression. The suprascapular notch was found to be stenosed beyond its capacity to accommodate the suprascapular nerve in 49/333. Type-V is at most risk followed by Type-III.

CONCLUSIONS

Suprascapular notch stenosis takes three morphological patterns: horizontal, vertical or mixed. An osteoplasty of suprascapular notch margins may be required beside the common surgical approach of the superior transverse scapular ligamentectomy.

"Suprascapular canal": Anatomical and topographical description and its clinical implication in entrapment syndrome

BACKGROUND

Suprascapular nerve (SN) entrapment syndrome accounts for 1-2% of all shoulder pain. The SN travels within a space between the suprascapular notch (SSN) and the spinoglenoid notch (SGN).

PURPOSE

To report a detailed topographical study of the suprascapular canal (SSC) and ultimately sort the different types of SN entrapment by its anatomical localization within the canal.

BASIC PROCEDURES

Observational study on 30 free dissected limbs of formaldehyde-fixed cadavers. The SN and vessels were traced as they passed through the SSC and the boundaries of the SSC were observed and documented. The SSC was then exposed by reflecting away the bordering muscles. Dimensions of the SSC as well as parameters of the SSN and SGN were measured using a digital caliper. Finally, a thorough literature review was made to survey the SN entrapment occurrence by site.

MAIN FINDINGS

The SSC is situated in the spinoglenoid fossa, has an average width of 13 mm, and runs underneath the supraspinatus muscle with an average distance of 25 mm between the SSN and SGN sloping in an infero-postero-lateral direction. The first segment represents the SSC entrance site and is composed of two spaces: osteofibrous and musculofibrous. The second segment is bordered by the supraspinatus muscle fascia, lateral margin of the supraspinous fossa, glenohumeral joint capsule, and the bony surface of the scapula (spinoglenoid fossa). This represents the SSC passage site. The third segment represents the SSC exit site around the spinoacromial arch at the SGN.

PRINCIPAL CONCLUSIONS

The SSC is defined as an osteofibrous canal running between the SSN and SGN enclosed by the supraspinatus fascia. It is anatomically composed of three segments: an entrance, a passage, and an exit. The distal SN passes through the SSC via five intervals that correspond to five potential sites of anatomical nerve entrapment: at the pre-entrance site, entrance site, passage site, exit site, and post-exit site. Each of those sites was found to be associated with specific causes and forms of entrapment.

Clinico-radiological review of peripheral entrapment neuropathies - Part 1 upper limb

PURPOSE

This article aims to review the pertinent anatomy, etiopathogenesis, current clinical and radiological concepts and principles of management in case of upper limb entrapment neuropathies.

METHODS

The review is based on critical analysis of the existing literature as well as our experience in dealing with entrapment neuropathies.

RESULTS

Entrapment neuropathies of the upper limb peripheral nerves are common conditions that are often misdiagnosed because of their varying clinical presentations and lack of standardized diagnostic methods. Clinical assessment and electrodiagnostic studies have been the mainstay; however, imaging techniques have provided newer insights into the pathophysiology of these entities, leading to a paradigm shift in their diagnosis and management. The current best practice protocols for entrapment syndromes are constantly evolving with increasing emphasis on the role high-resolution ultrasound and magnetic resonance imaging. Many imaging criteria are described and we have tried to present the most validated measurements for diagnosing entrapment neuropathies.

CONCLUSION

It is imperative for a clinical radiologist to be familiar with the etiopathogenesis and clinical features of these conditions, in addition to being thorough with the anatomy and the latest imaging strategies.

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 entrapment in young kayaker: a case report

Kayaking has become one of the most popular paddle sports throughout the world. The shoulder is the most commonly injured area of the body among kayaking participants as a result of acute traumatic events and chronic overuse injuries. Therefore, kayaking participants may often seek advice for shoulder problems and there is a scarcity of studies regarding shoulder injuries in this population. In this case report, we present a young male recreational whitewater kayaker with a severe suprascapular nerve (SSN) entrapment who presented with shoulder pain and inability to perform his sport. He was initially evaluated elsewhere and was treated with nonsteroidal anti-inflammatory medications and physical therapy for presumptive diagnosis of subacromial impingement. After 5 months of failed non-operative treatment, the patient sought a second opinion with our group. SSN entrapment diagnosis was confirmed by a thorough careful physical examination, magnetic resonance imaging and electrodiagnostic study. Given the failure of non-operative treatment, the patient was treated with arthroscopic SSN decompression and successfully returned to kayaking without symptoms. While SSN entrapment has been reported in a variety of sports, especially those involving overhead movements, this is the first case report of SSN entrapment reported which impaired participation in kayaking. This case report supports the consideration of SSN entrapment in the differential diagnosis of painful shoulder among kayaking participants and highlights the importance of undressing the patient and examining the posterior shoulder for atrophy, winging or deformity.

Coexistence of a rare case of a suprascapular artery with other vascular abnormalities: case report and potential surgical relevance

PURPOSE

The suprascapular artery originates in the thyrocervical trunk; however, several variations regarding both the origin and the path have already been described. This article aims to describe a complex and rare variation of the suprascapular artery originating as a branch of the subscapular artery. We described, reviewed the literature, and highlighted the clinical relevance of such variations to the medical practice.

METHODS

A routine dissection was performed on a male adult cadaver approximately 60-70 years old, embalmed in formalin 10%. In addition, the diameter of the axillary, subscapular and suprascapular arteries was measured.

RESULTS

During the dissection, we identified the suprascapular artery emerging from the medial side of the subscapular artery with a long and tortuous pathway to the supraspinatus fossa, under the superior transverse scapular ligament. Associated with this, three other anatomical variations stand out: the posterior circumflex humeral artery emerging from the subscapular artery, the absence of the anterior circumflex humeral artery, and two pectoral branches emerging from the third part of the axillary artery and from the subscapular artery, respectively.

CONCLUSION

Such variations are of great clinical relevance to orthopedists, mastologists, vascular surgeons and other specialties for both surgical approaches and suprascapular neuropathy.

The Anatomical Variation of the Scapular Spine in A Chinese Population

Background

The occurrence of fractures and risks following reverse total shoulder arthroplasty (rTSA) is common due to the variation of scapular spine (SS). Therefore, the consideration of the variable osteological features of SS prior to surgery may prove to be significant for the implementation of rTSA. This study aimed to propose a classification of SS through particular and quantitative parameters.

Material/Methods

In total, 354 intact dry scapulae were geometrical measured and classified on account of anatomical characteristics and the shapes of SS.

Results

Type I SS was found, and this was the most frequency was type (27.97%). The least common type was type II. The type of SS had a direct association with bone stock and bone mineral density. Type II represented an association with a much thinner spine and restricted cortical and cancellous bone; types II and V were also associated with a crooked SS, which had a more complex morphology.

Conclusions

This study offered a comprehensive classification of SS in the Chinese population. On the whole, this study indicates that knowledge of the morphological variations of SS can prompt the diagnosis of scapular fractures and can promote more successful rTSA procedures, and the relative clinical trial is necessary to support it.

Anatomical and radiographic study of the scapula in juveniles and adults of Tamandua mexicana (Xenarthra: Myrmecophagidae)

Tamandua mexicana is a mammal of the superorder Xenarthra geographically located between Mexico and Peru that remains insufficiently studied. These species are characterized by their movement, resting, and eating of termites and ants in arboreal and terrestrial environments, and therefore, their thoracic limbs have been adapted morphologically to move in these environments. Tamandua mexicana is a species constantly threatened by different causes, and their thoracic limbs can be affected in the scapular and shoulder regions as a result; therefore, specific anatomical knowledge of the scapula allows for better clinical procedures, surgical approaches, radiological diagnosis and muscular reconstructions in extinct species of anteaters. The main objective of this study was to report the anatomical and radiographic features of the scapula in juvenile and adult specimens of T. mexicana. Gross dissections and radiographic study were performed in six cadavers. The scapula had large differences compared with other mammals, such as two spines, a foramen for the suprascapular nerve, a long acromion, a cranial transverse scapular ligament and caudolateral fossa for the origin of the muscles teres major, tensor fasciae antebrachii and subscapular. In juvenile specimens, a scapular cartilage, an acromial cartilage, craniomedial and caudolateral coracoscapular ligaments forming the foramen for the suprascapular nerve, and progressive ossification of those ligaments and the cranial transverse scapular ligament were observed. These findings were corroborated by radiography; therefore, these characteristics change with age. The bony reliefs of the scapula of T. mexicana corroborate the specialization of the shoulder in this species.

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.

The Incidence of Ossified Superior Transverse Scapular Ligament during Nerve Transfer through Posterior Shoulder Approach

BACKGROUND

The purpose of this study was to assess the incidence and importance of bony bridge that covers the supra scapular notch during posterior approach to transfer accessory nerve to suprascapular nerve.

METHODS

Between 2010 and 2015, the frequency and importance of suprascapular bony bridge instead of transverse ligament was assessed among patients with brachial plexus injury candidate to shoulder function restoration by accessory to suprascapular nerve transfer through posterior approach.

RESULTS

Forty three patients, 41 male and 2 female, (mean age: 32.5 years, range 14 to 36) were included in this study. Five male patients (11.6%) had a complete bony rim on the superior scapular notch. Suprascapular nerve release needed osteotomy of the bony bridge and related equipment.

CONCLUSION

Although all previous cadaveric studies among different ethnic groups had reported the prevalence between 0.3 to 30% of suprascapular canal, this in vivo study showed the incidence of 11.6%. Preoperative alertness about this variation could make the exploration and release of the suprascapular nerve easier and reduce the risk of nerve injury or failing to anatomize it.

LEVEL OF EVIDENCE

IV.

Distribution and Morphological Measurement of Bony Spurs on the Coracoid Process in a Chinese Population

Background

There are few studies on distributions or morphological measurements for bony spurs form at the attachment points of the ligaments and tendons on the coracoid process. The aim of this study was to investigate their most common sites and morphological characteristics, and to propose possible reasons.

Material/Methods

Scapulae with bony spurs on the coracoid process were selected from 377 intact and dry Chinese scapulae. The distribution, height, and transverse and longitudinal diameter of the bony spurs were measured in each coracoid process.

Results

We selected 71 scapulae, 36 left and 35 right, that had bony spurs, from 377 scapulae. The bony spurs were most commonly located at the attachment point of the superior transverse scapular ligament (STSL) (31, 23.66%), while the trapezoid ligament (TL) accounted for the smaller proportion (8, 6.11%). The TSL was the highest, with the minimum transverse and longitudinal diameter, while the TL had the greatest transverse and longitudinal diameters. Only the TSL and TL had a statistically significant difference between the left and the right bony spur regarding the longitudinal diameter (P<0.05).

Conclusions

Bony spurs are more likely to form at the attachment points of ligaments and tendons on the coracoid process, which has a greater risk of traction injuries or attachment points avulsion fractures.

Morphometric, anatomic and radiographic study of the scapula in the white-footed tamarin (Saguinus leucopus): report of scapular cartilage and one variation in cranial (superior) transverse scapular ligament

The white-footed tamarin (Saguinus leucopus) is an endangered endemic primate of Colombia, mainly due to the deforestation of its habitat and illegal trade, which generates a high incidence of these animals in wildlife care centres. Musculoskeletal system disorders in S. leucopus are one of the most common diseases and therefore the aim of this study was to contribute to the morphologic studies with a morphometric, anatomic and radiographic description of the scapula in this species to provide a basis for medical interventions, surgical approaches, radiologic diagnoses and comparative functions of this bone. Gross dissections of each scapular region were made in eight specimens without a diagnosis of osteomuscular disease. These specimens died from natural cases in the wildlife care centres of the Corporación Autónoma Regional de Caldas (CORPORCALDAS); after necropsy their carcasses were fixed with 10% formaldehyde, 5% mineral oil and 1% phenic acid in these centres over the course of at least 1 week. X-rays of the scapula were taken in the small animal clinic of the Universidad del Tolima, and morphometric data of the scapulae were obtained with a digital calliper. The scapula of the white-footed tamarin was a flat triangular bone with a deep scapular notch in its cranial margin, where there was a cranial transverse scapular ligament that was absent in two specimens. The coracoid process was highly developed, medially covering the humeral joint. The dorsal margin was covered by the scapular cartilage, which was highly developed in the caudal angle. In the dorsal fourth of the caudal margin, there was a surface from which the m. teres major originated. The lateral surface had a scapular spine with a long hamatus process of the acromion until the lateral part of the humeral joint. The infraspinatus fossa was wider than the supraspinous fossa. On the costal surface, the subscapular fossa was formed by three subscapular lines and one subscapular ridge, the latter helping to form the surface for the m. teres major. In the two radiographic views, caudocranial to the scapula and dorsoventral to the thorax, the scapular spine, acromion, coracoid process, scapular incisura, supraglenoid tubercle, caudal margin, subscapular ridge, and the joints with the clavicle and the humerus could be observed. The scapula of the white-footed tamarin presented bony reliefs that share characteristics with other primates but also with domestic mammals due to its quadrupedal locomotion, which allowed us to correlate its morphologic adaptation with its quadrupedal arboreal displacement.

Morphological Aspects in Ultrasound Visualisation of the Suprascapular Notch Region: A Study Based on a New Four-Step Protocol

Background: Sonographic evaluation of the suprascapular notch (SSN) region is clinically important, because it is the most common location for performing suprascapular nerve block. The aim of the study was to describe the morphology of the SSN region based on ultrasound examination and in accordance with the patients’ body mass index (BMI). Material and Methods: The SSN region was sonographically examined in 120 healthy volunteers according to our new four-step protocol. The morphometry of the SSN and the neurovascular bundle was assessed, and patients’ BMI were calculated. The shape of the suprascapular notch was classified based on its superior transverse diameter (STD) and maximal depth (MD). Result: The type III scapular notch was the most prevalent (64%). The BMI was higher in type IV/V (27.38 ± 3.76) than in type I (24.77 ± 3.49). However, no significant differences were observed in the distribution of SSN notch types with regard to BMI (p = 0.0536). The suprascapular artery was visualised in all of the recognised SSNs, while the suprascapular vein and nerve were visualised only in 74.9% and 48.1% of the SSNs, respectively. The suprascapular nerve was significantly thicker on the right side (3.5 ± 1.1 mm) than on the left (1.3 ± 0.4 mm) (p = 0.001). In contrast, the suprascapular vein (1.5 ± 0.9 mm) was found to be a significantly wider on the left side than the right (1.2 ± 0.7 mm) (p = 0.001). Conclusion: Our original four-step sonographic protocol enabled characterising the morphology of the SSN region, despite the SSN notch types. The suprascapular artery is the best sonographic landmark for the suprascapular notch region. No significant differences were found between sides regarding the thickness of the soft tissue above the suprascapular nerve and vessels. Recognition of the SSN morphology is not affected by the BMI.

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.

Protective and Predisposing Morphological Factors in Suprascapular Nerve Entrapment Syndrome: A Fundamental Review Based on Recent Observations

Suprascapular nerve entrapment syndrome (SNES) is a neuropathy caused by compression of the nerve along its course. The most common compression sites include the suprascapular notch and the spinoglenoid notch. The aim of this article was to review the anatomical factors influencing the occurrence of SNES in the light of the newest reports. Potential predisposing morphological factors include a V-shaped, narrow, or "deep" suprascapular notch; a band-shaped, bifurcated, or completely ossified superior transverse scapular ligament (STSL); particular arrangements of the suprascapular nerve and vessels at the suprascapular notch. A very recent report indicates structures at the suprascapular notch region that may protect from SNES, such as the suprascapular notch veins (SNV). The role of the anterior coracoscapular ligament (ACSL) is still not clear. While some studies indicate that it may predispose for SNES, the newest study proposes a protective function. Knowledge of these variations is essential for arthroscopic and other surgical procedures of this area in order to avoid iatrogenic injury of the suprascapular nerve or unexpected bleeding from the suprascapular vessels running alongside the STSL.

Unusual morphology of scapulae: incidence and dimensions of ossified ligaments and supraspinous bony tunnels for clinical consideration

INTRODUCTION

Knowledge of morphological variations of the suprascapular region is important in the management of entrapment neuropathy and interventional procedures. The objective of this study was to collect data on the morphological features and dimensions of ossified ligaments and unusual bony tunnels of scapulae from a North Indian population.

METHODS

A total of 268 adult human scapulae of unknown gender were obtained from the bone bank of the Department of Anatomy, Dayanand Medical College and Hospital, Ludhiana, Punjab, India. The scapulae were evaluated for the incidence of ossified superior transverse scapular ligaments (STSLs), ossified inferior transverse scapular ligaments (ITSLs) and bony tunnels (i.e. the bony canal between the suprascapular notch and spinoglenoid notch), found along the course of the suprascapular nerve (SSN). The dimensions of these structures were measured and noted down. Ossified STSLs were classified based on their shape (i.e. fan- or band-shaped) and the dimensions of the ossified suprascapular openings (SSOs) were measured.

RESULTS

Ossified STSLs were present in 26 (9.7%) scapulae. Among the 26 scapulae, 16 (61.5%) were fan-shaped (mean area of SSO 16.6 mm(2)) and 10 (38.5%) were band-shaped (mean area of SSO 34.2 mm(2)). Bony tunnels were observed in 2 (0.75%) specimens, while an ossified ITSL was observed in 1 (0.37%) specimen.

CONCLUSION

The data obtained in the present study augments the reference literature for SSN decompression and the existing anatomical databases, especially those on Indian populations. This data is useful to clinicians, radiologists and orthopaedic surgeons.

Anterior Coracoscapular Ligament as a Factor Predisposing to or Protective for Suprascapular Neuropathy

Suprascapular neuropathy is a pathology caused by injury or compression of the suprascapular nerve. As the nerve runs from the anterior to posterior side of the scapula, the hot point where it is most susceptible to both injury and compression is the suprascapular notch. A literature search reveals several potential predisposing morphological factors in this area. However the most recent reports indicate that the structures at the suprascapular notch region may also prevent nerve injury and compression. The role of the anterior coracoscapular ligament (ACSL) remains unclear. While some studies indicate that it may predispose to suprascapular neuropathy, the newest study proposes a protective function. The aim of the article was to review the function of the anterior coracoscapular ligament in the light of the most recent studies. An understanding of the role of the ligament is essential for arthroscopic and other surgical procedures of this area in order to avoid iatrogenic injury of the suprascapular nerve.

Sex and gender disparity in pathology, disability, referral pattern, and wait time for surgery in workers with shoulder injury

BACKGROUND

The role of sex as an important biological determinant of vulnerability to sustaining injury and gender as a social determinate of access to resources, referral for medical care and perceived disability remains conflicted in injured workers. The purpose of this study was to examine sex and gender disparity following a compensable work-related shoulder injury.

METHODS

This study involved cross-sectional analyses of data of two independent samples of workers with shoulder injury. Measures of disability and pain were the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) and Numerical Pain Rating Scale (NPRS) for patients seen at an Early Shoulder Physician Assessment (ESPA) program and the American Shoulder and Elbow Surgeons (ASES) assessment form and Visual Analogue Scale (VAS) for the sample who underwent surgery.

RESULTS

The files of 1000 (443 females, 557 men) consecutive patients seen at an ESPA program and 150 (44 females, and 106 men) consecutive patients who underwent rotator cuff surgery (repair or decompression) were reviewed. Significant gender disparity was observed in the referral pattern of injured workers seen at the ESPA program who were referred for surgical consultation (22 vs. 78 % for females and males respectively, p < 0.0001). The independent rotator cuff surgical group had a similar gender discrepancy (29 % vs. 71 %, p < 0.0001). The timeframe from injury to surgery was longer in women in the surgical group (p = 0.01). As well, women waited longer from the date of consent to date of surgery (p = 0.04). Women had higher incidence of repetitive injuries (p = 0.01) with men reporting higher incidence of falls (p = 0.01). Women seen at the ESPA program were more disabled than men (p = 0.02). Women in both samples had a higher rate of medication consumption than men (p = 0.01 to <0.0001). Men seen at the ESPA program had a higher prevalence of full thickness rotator cuff tears (p < 0.0001) and labral pathology (p = 0.01). However, these pathologies did not explain gender disparity in the subsample of ESPA who were referred for surgical consultation or those who had surgery.

CONCLUSIONS

Sex and gender disparity exists in workers with shoulder injuries and is evident in the mechanism of injury, perceived disability, medication consumption, referral pattern, and wait time for surgery.

The Ossified Bifid Superior Transverse Scapular Ligament Causing a Double Suprascapular Foramen: A Case Report

Ossified bifid superior transverse scapular ligament causing a double suprascapular foramen is a very rare finding. This ossified ligament reduces the suprascapular space by half of its original size. It is one of the precipitating factors of suprascapular nerve entrapment. Here we describe a double suprascapular foramen in a dry left scapula of Indian origin. There were two bony bars bridging the suprascapular notch thereby making two foramina. The bony bars were 'V' shaped with its apex attached to the lateral side of the suprascapular notch. The upper foramen was large and triangular whereas the lower foramen was small and oval. Considering the shape of the foramen and the 'V' shaped attachment of the bony bars, we conclude it to be due to the ossification of bifid superior transverse scapular ligament. A double suprascapular foramen should always be kept in mind while diagnosing and treating suprascapular nerve entrapment. Knowledge about the double suprascapular foramen would be useful to orthopaedic surgeons who perform decompression for suprascapular nerve entrapment through arthroscopy and open procedures.