Superior Transverse Scapular Ligament Research Articles

Occupancy of the Suprascapular Notch by the Suprascapular Nerve: An Anatomic Study

The purpose of the study was to evaluate the dimensions of the suprascapular nerve and the suprascapular notch in freshfrozen cadaveric shoulders and to calculate the occupancy ratio of the notch, i.e. the space occupied by the suprascapular nerve and the superior transverse scapular ligament (STSL). The suprascapular nerve and the suprascapular notch were dissected, and the following parameters were included in the study: presence and shaper of the notch, dimensions of the lower border of the superior transverse scapular ligament and dimensions of the notch and the dimensions of the suprascapular nerve in two directions perpendicular to each other. All measurements were performed using a digital Vernier caliper. The cross-sectional area of the suprascapular nerve was assumed to be elliptical; the area of a U-shaped notch was assumed to be semi-elliptical and the area of the triangular-shaped notch were calculated accordingly. The area of the between the various notch types and the cross-sectional area of the suprascapular nerve in the various notch types were statistically compared. The reliability of continuous measurements was analyzed using intraclass correlation coefficients (ICCs). The suprascapular notch was present in all cases. A U-shaped notch was the most common type (22, 69%) followed by a triangular-shaped notch (10, 31%). The interobserver reliability of the suprascapular nerve and notch dimensions was excellent (ICC = 0.92 and 0.96 respectively). The cross-sectional area of the suprascapular nerve was 5.982.34 mm2 with no difference between the two body sides. The cross-sectional area of the U-shaped suprascapular notch was significantly larger than that of the V-shaped notch (19.98 5.34 mm2 versus 13.777.34 mm2, p=0.02). Correspondingly, the occupancy of the suprascapular notch by the suprascapular nerve was higher in V-shaped rather than U-shaped notches (37.199.34% versus 49.417.32%, p=0.03).

The superior transverse scapular ligament and its relation to the suprascapular Neurovascular triad: Anatomical study and clinical significance

BackgroundThe anatomical variations at the suprascapular region have great impact on the suprascapular nerve and its entrapment syndrome. AimThis study aimed to describe the morphological types and morphometric parameters of the superior transverse scapular ligament (STSL) and its relation to suprascapular neurovascular triad. Material & methodsThe suprascapular region was dissected in 60 (40 male & 20 female) cadaveric shoulders. The morphological variants, length, widths, thickness of STSL, and its relation to suprascapular triad were evaluated. ResultsFive morphological types of STSL were identified. The common variant was the fan-shaped followed by the band-shaped and the triangular-shaped, while the ossified and bifid forms revealed lower incidence rates with no side or sex significant difference. Morphometrically, the length of STSL measured 16.4 ± 2.4 mm, medial width was 13.3 ± 3 mm and its lateral width measured 5.4 ± 1.3 mm with no side significant difference (p > 0.05). Moreover, its length measured 16.6 ± 2.6 mm in male and 15.8 ± 1.9 mm in female, its medial width was 13.7 ± 2.2 mm in male and 12.2 ± 2 in female, and its lateral width measured 5.6 ± 1.3 in male and 5.1 ± 1.1 mm in female specimens. The relation between the suprascapular triad and STSL showed three main variants: where the blood vessels pass above the STSL (56.7 %), followed by the passage of the artery above and the vein below STSL (23.3 %), and the blood vessels below STSL (11.7 %). ConclusionKnowledge the morphological variants and morphometric measurements of STSL and its relation to the suprascapular triad are important during surgical and arthroscopic procedures of the shoulder region.

Morphological types and morphometrical measurements of the suprascapular notch in both dry bones and human cadavers: anatomical study to improve the outcomes of the diagnostic and interventional procedures in the shoulder region.

Understanding the anatomy of suprascapular area helps the clinicians and surgeons in management of any disability at the shoulder region. This work aimed to clear the different morphological and morphometrical types of suprascapular notch (SSN). Unknown 120 dry human scapulae of both sides and 60 formalin-embalmed cadaveric upper limbs (40 males and 20 females) were used in the present study. Three main morphological forms of SSN were reported: J, U, and V-shaped. J-shaped notch showed the highest incidence followed by U-shaped then V-shaped one. Morphometrically, type (III) notch was the most prevalent in both dry bones and cadavers, while the incidence of type (II) was the lowest form. Also, the measurements of superior transverse diameter, middle transverse diameter and vertical dimension of the different types of the notch showed no side or sex significant difference. The suprascapular foramen with ossified superior transverse scapular ligament (STSL) was seen in 5.8% of dry bones and 10% of cadaveric specimens. Fan and band-shaped ossified transverse scapular ligaments were reported. Absence of SSN was seen in 10.8% of dry bones, 7.5% of male and 10% of female specimens with left side predominance. V-shaped, absence, and ossified STSL were considered as predisposing factors of suprascapular nerve entrapment syndrome. Knowledge of the morphology and morphometric parameters of SSN is of great clinical significance for anatomists, radiologists, physiotherapists, orthopedics and neurosurgeons to perform good diagnosis and best planning for surgical or arthroscopic interventions within the shoulder region.

An unusual combination of a bilateral aberrant suprascapular artery with neurovascular structures variants

PurposeThe report describes a bilateral suprascapular artery (SPSA) of atypical origin in coexistence with neurovascular aberrant structures.MethodsThe variants were identified in a 91-year-old formalin-embalmed male cadaver, derived from a body donation program after a signed informed consent.ResultsThe left-sided SPSA emanated from the 1st part of the axillary artery, coursed between the brachial plexus lateral and medial cords, accompanied by the suprascapular nerve, and passed below the superior transverse scapular ligament. Ipsilateral coexisted variants were the lateral thoracic artery multiplication, the subscapular trunk formation, and the musculocutaneous nerve duplication. In the right supraclavicular area, a SPSA duplication was identified. The main artery emanated from the thyrocervical trunk in common with the transverse cervical artery and the accessory SPSA emanated from the dorsal scapular artery. Both SPSAs coursed over the superior transverse scapular ligament, while the suprascapular nerve ran below the ligament.ConclusionsThe current study reported a bilateral aberrant SPSA, originating from the AA 1st part (left side) and from the dorsal scapular artery (right side), which coexisted with adjacent neurovascular structures’ variants. The left SPSA atypically coursed below the superior transverse scapular ligament. Such an unusual combination of variations, present bilaterally in the current study, may be challenging for radiologists and surgeons.

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.

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

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. 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). 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. 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.

Comparison of Anterior vs. Dorsal Approach for Spinal Accessory to Suprascapular Nerve Transfer in Patients With a Brachial Plexus Injury and Its Outcome on Shoulder Function.

BackgroundBrachial plexus injuries are frequently encountered in the domain of plastic surgery, mostly secondary to road traffic accidents, gunshot injuries, or falls from a height. Many modalities have been described in the management, depending on the level and duration of the injury. C5, C6 and C5, C6, C7 are two common patterns in which nerve repair and transfers are described. At our center, we practice spinal accessory to suprascapular nerve transfer in all patients with upper trunk brachial plexus injury. There are two described approaches for the spinal accessory nerve to suprascapular nerve transfer, i.e. anterior or dorsal. The rationale for doing the posterior approach is that this approach avoids damaging the suprascapular nerve at its entrance in the suprascapular notch under the suprascapular ligament during exploration due to traction.Materials and methodsThis is a retrospective study with a consecutive sampling of 23 patients presenting at Liaquat National Hospital, Karachi, with upper trunk brachial plexus injuries during the time period from January 2016 to December 2017, i.e. two years. We divided these 23 patients into two groups, one with the anterior approach and the other with a dorsal approach for spinal accessory to suprascapular nerve transfer for shoulder abduction. The mean duration of post-surgical follow-up was from 18 to 24 months and recovery and functional outcomes were assessed.ResultsOut of the 23 patients that were included, 10 patients were operated on with an anterior approach and 13 with a posterior approach. Fifty percent (50%) of patients operated with the anterior approach and 84% of patients with the posterior showed the best motor grade recovery of M4, respectively, with better performance in patients with the posterior approach as compared to the anterior approach.ConclusionWe advocate taking a posterior approach for spinal accessory to suprascapular nerve transfer for shoulder abduction, as it has shown better results with reliable outcomes concerning shoulder abduction, angle of abduction, and range of motion.

Variations in the Course and Diameter of the Suprascapular Nerve: Anatomical Study.

(1) Background: Suprascapular neuropathy is an important factor contributing to shoulder pain. Given the prevalence of nerve injury and nerve block in the suprascapular notch region, as well as the frequency of arthroscopic procedures on the suprascapular notch, which are recommended in shoulder pain management, its morphology is relevant from a clinical perspective. (2) Methods: Suprascapular nerve course was studied in twelve shoulders by dissection. Its diameter was measured at omohyoid level, proximal to the suprascapular notch and distal to the spinoglenoid notch. A multi-vari chart was used in order to descriptively visualize the results. The variations found were analyzed with a mixed linear model. (3) Results: In two of the six subjects, the suprascapular nerve was divided into two motor branches proximal to the superior transverse scapular ligament. An increase in diameter around the suprascapular notch was detected, with an estimated difference between diameter means of 2.008 mm at the suprascapular notch level and 2.047 mm at the spinoglenoid notch level. (4) Conclusions: A difference in the estimated diameter detected and the fact that the motor branches, which innervate supraspinatus and infraspinatus muscle, were divided proximal to the suprascapular notch may be relevant in the diagnosis and treatment of suprascapular neuropathy and arthroscopic procedures.

Morphological and Morphometric study of suprascapular notch

Variation in the morphology of suprascapular notch is associated with suprascapular nerve entrapment neuropathy. So, the knowledge about different shapes of suprascapular notch is important for clinicians in understanding the source of the entrapment syndrome. The Shapes of suprascapular notch are of five in types - Deep U Shaped, shallow U Shaped, J Shaped, V Shaped &amp; indented shaped. Deep U shape is most common &amp; Indented is least common type of suprascapular notch. Suprascapular notch is semicircular in shape, situated in the superior border of the scapula just below the base of the coracoid process. Suprascapular notch is converted to the foramen by the attachment of the suprascapular ligament. Suprascapular vessels passes above the ligament &amp; Suprascapular nerve passes below the ligament. In present study morphological data were obtained and classify the suprascapular notch according to their shape. Present study was conducted on 70 dry human scapulae of both sides with unknown age &amp; sex. This study was conducted in the Department of Anatomy, Hind Institute of Medical Sciences, Barabanki. In the Present study Anatomical variation were found in suprascapular notch which included shape, partial &amp; complete ossification of superior transverse ligament.

Correlation between Morphological Variations and Morphometry of Scapula and Suprascapular Notch with Its Clinical Significance in South Indian Population

Introduction: The biological profile is one of the most important things that forensic anthropologists accomplish in their work, which includes determination of age, sex, race and stature. These components aid in identification of an individual in forensic context. Since the beginning of the field of physical anthropology, anthropologists and anatomists have studied human remains in order to provide new and more accurate ways of building the biological profile. Aim: To compare the metric difference between right and left scapula, calculate scapular index, and to correlate the morphometry between the scapula and the suprascapular notch. Materials and Method: This study was carried out in 200 dry ossified adult human scapula bones collected from the Department of Anatomy and from the students of 1st year MBBS of Yenepoya Medical College. Study done using vernier calliper and measuring tape. Scapula having gross deformity or any pathological alterations were excluded from the study. Results and Discussion: Out of 100 right and left scapulae, maximal width and projection length of scapular spine and maximal length of coracoid process were more on the right sided scapula. The superior- transverse diameter of suprascapular notch, maximal depth of suprascapular notch, morphological length and width of scapula and scapular index were more on the left sided scapulae. The mean scapular index of right side scapula was 70.11 and left side was 70.26, which shows that the left scapula is slightly shorter than right. Also there were more scapulae with longer superior transverse diameter of suprascapular notch (STD&gt;MD) with 52% than the scapulae with longer maximal depth of suprascapular notch (MD&gt;STD) 24% and STD=MD was 9%. Absent notches were seen in 15% of scapulae. The superior transverse scapular ligament was completely ossified in 12% of cases. Both right and left scapula shows more of ‘U-shaped’ suprascapular notch. There was no statistically significant difference between anthropometric measurements of the group with higher maximal depth and the group with higher superior transverse diameter of the suprascapular notch. Conclusion: The scapular index was more in left scapula, which shows that left scapula is slightly shorter than the right scapula compared to other populations. This may be due to the difference in general built and stature of South Indians compared to other populations. Completely ossified superior transverse scapular ligament can result in entrapment of suprascapular nerve. Keywords: Scapula, Suprascapular notch, Spine of scapula, Coracoid process.

Morphometric study of the suprascapular notch and scapular dimensions in adult Malawian cadavers and implications of completely ossified superior transverse scapular ligament.

Introductionthe anatomy of the suprascapular notch and its relationship to scapular dimensions are critical in the management of suprascapular neuropathies. Individuals show considerable differences in the dimensions of the suprascapular notch across populations. The purpose of this study was to determine the morphology and morphometric dimensions of the suprascapular notch in adult Malawian cadavers and to suggest clinical implications associated with complete ossification of the suprascapular ligament.Methodsadult dry scapulae from undetermined sex specimens (n=125) obtained from the skeletal collection at Kamuzu University of Health Sciences were classified according to the Rengachary categorization method to assess the suprascapular notch superior transverse distance, mid transverse distance, depth, scapula length and width using a standard Vernier caliper.Resultsthe most prevalent suprascapular notch class was type I, which was found in 46 (36.8%) of all scapulae. Type VI was the least common, found in only 1 (0.8%) of the scapulae. The mean notch superior transverse distance was 1.3 ± 0.6 cm, while the mean maximum depth was 0.6 ± 0.3 cm. Only the differences in depth, however, were statistically significant (p=0.001).Conclusionthe current study has described the morphology and morphometry of the suprascapular notch in relation to the risk of suprascapular nerve entrapment associated with complete ossification of the suprascapular ligament. Our sample population generally showed smaller suprascapular notch and scapular dimensions than other populations. This should be considered during the management of suprascapular neuropathy and preoperative planning of surgical operations of the shoulder region.

Suprascapular Nerve Entrapment by Labral Cyst Associated with Labral Lesion: A Case Report

Background: The suprascapular nerve is a mixed motor and sensory nerve originating from the brachial plexus. It passes between the suprascapular notch and superior transverse scapular ligament into the posterior surface of the scapula, which dominates the supra- and infraspinatus muscles. Suprascapular nerve entrapment is an uncommon but significant cause of shoulder pain. Objective: We report a 30-year-old man who had a complaint of right shoulder pain and external rotation weakness that lasted for 4 years which was diagnosed as labral lesion associated with suprascapular nerve entrapment. Conclusion: Patient underwent surgical repair of labral lesion with debridement of the cyst. Follow-up for 12 months postoperatively showed that patient shoulder pain improved significantly and external rotation improved (45-50°).

A Study on Suprascapular Foramen and Its Clinical Importance: A Cadaveric Study in Western Part of Tamilnadu, India

Background: Suprascapular notch is present along the superior border of the scapula close to the lateral angle, which is converted into a Suprascapular foramen by the transverse Suprascapular ligament. Normally the Suprascapular nerve and vein pass through the foramen below the ligament, while the Suprascapular artery runs above the ligament. Suprascapular nerve entrapment is an interesting clinical condition which is widely involved in this area. Aim of the study: To find out the presence of Suprascapular artery passing along with the Suprascapular nerve and vein within the foramen and any pathology associated with it. Materials and Methods: The proposed study is carried out in the Department of Anatomy, Karpagam Faculty of Medical Sciences and Research, Coimbatore, where 51 well embalmed cadavers of both the sexes and various age groups was utilised. Results: Out of 51 cadavers dissected, we found Suprascapular artery was found passing along with the Suprascapular nerve and vein in 2 of the cadavers, of which one each is found in a male and a female cadaver with an incidence of 3.92%. Conclusion: Studies done earlier pointed out the importance of Suprascapular nerve entrapment, the various causes and predisposing factors responsible for it ,and a knowledge of safe zone around the shoulder region should be known well to the operating surgeon and the available imaging techniques should be utilised by the radiologists in order to avoid the complications while dealing with the Suprascapular nerve entrapment. KEY WORDS: Cadaver, Suprascapular foramen, Suprascapular artery, Nerve entrapment, Transverse Suprascapular ligament.

Pathological findings identified during the posterior approach to the spinal accessory nerve after high-energy trauma.

The spinal accessory to suprascapular nerve transfer is a key procedure for restoring shoulder function in upper brachial plexus injuries and is typically undertaken via an anterior approach. The anterior approach may miss injury to the suprascapular nerve about the suprascapular notch, which may explain why functional outcomes are often limited. In 2014 we adopted a posterior approach to enable better visualization of the suprascapular nerve at the notch. Over the next 6years we have used this approach for 20 explorations after high-energy trauma. In 7/20 we identified abnormalities at the level of the suprascapular ligament, which we would not have identified with an anterior approach: there were two ruptures, two neuromas-in-continuity and three cases of scar encasement, necessitating neurolysis. Nerve transfer could be undertaken distal to the suprascapular notch, bypassing the site of injury. These pathological findings support the wider adoption of the posterior approach in cases of high-energy trauma.Level of evidence: IV.

Suprascapular Nerve Entrapment by a Trifid Superior Transverse Scapular Ligament

AbstractAnatomical variations at the suprascapular notch may limit the available space for the suprascapular nerve (SSN), and cause its entrapment in the tight osseoligamentous tunnel. The author encountered the presence of a trifid superior transverse scapular ligament (STSL) while operating on a patient with SSN entrapment. Surgical division of the three bands resulted in complete regression of symptoms.

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

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. Two hundred and seventy-six computed tomography images were retrospectively analyzed, which included those of both scapulae of Asian patients (mean age, 62.1 ± 19.1years; 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. 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 > 70years than in those aged < 70years. Fifteen patients had type VI SSNs, which were unilateral in 10 patients. 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. III.

Outcomes of Arthroscopic Nerve Release in Patients Treated for Large or Massive Rotator Cuff Tears and Associated Suprascapular Neuropathy: A Prospective, Randomized, Double-Blinded Clinical Trial

Background: Suprascapular neuropathy has been observed in the setting of rotator cuff tears (RCTs), but its association with these tears and their treatment are unclear. Hypothesis: Arthroscopic suprascapular nerve release during rotator cuff repair will not alter the outcomes of neuropathy. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 42 patients with large/massive reparable RCTs and suprascapular neuropathy were recruited and followed up at 6 and 12 months. Electrophysiological results as well as Disabilities of the Arm, Shoulder and Hand (DASH), American Shoulder and Elbow Surgeons (ASES), and Constant scores were evaluated at selected time periods. Patients were randomly assigned to 2 groups. Patients in the control group underwent arthroscopic repair of the rotator cuff without combined arthroscopic release of the superior transverse scapular ligament; in the second group, the superior transverse ligament was released. The primary outcome was to examine full suprascapular nerve recovery through electrophysiological changes between groups. The secondary/tertiary outcomes were analysis of clinical outcomes and assessment of the relation between RCT size and the degree of suprascapular nerve recovery. Patients, clinical staff members, and the neurologist were blinded to the type of surgical procedure. Results: Of 42 patients, 37 completed the follow-up at 12 months (median age, 64 years [range, 50-75 years]). Overall, 17 of 19 (89.5%) patients in the control group and 15 of 18 (83.3%) patients in the nerve release group had full nerve recovery, with no significant difference between the 2 groups. Clinically, all patients in both groups showed a significant improvement (P < .001), but no significant difference was observed between the 2 groups in terms of 12-month postoperative scores (control group: DASH: median, 5 [range, 0-21]; ASES: median, 88 [range, 83-98]; Constant: median, 86 [range, 70-98]) (nerve release group: DASH: median, 6 [range, 0-25]; ASES: median, 90 [range, 83-98]; Constant: median, 88 [range, 75-98]). Also, no significant difference was found between the 2 groups regarding other secondary and tertiary outcomes. Conclusion: Combined arthroscopic release of the superior transverse scapular ligament and rotator cuff repair in patients with large/massive RCTs and suprascapular neuropathy did not produce statistically significant improved outcomes compared with repair of the rotator cuff alone. Registration: NCT02318381 (ClinicalTrials.gov identifier).

Letter to the Editor: Regarding "An Unusual Bilateral Duplication of the Suprascapular Vein and Its Relation to the Superior Transverse Scapular Ligament Revealed by Anatomage Table".

No abstract available.

MRI-Evaluation of Suprascapular Notch Morphometry and Its Clinical Applications

The suprascapular notch, a depression on the lateral part of the superior border of the scapula, medial to the coracoid process, is covered by the superior transverse scapular ligament, which is converted into a foramen. Sometimes it might be ossified forming a complete osseous foramen. The Suprascapular Notch (SN) served as a passage for the Suprascapular Nerve (SSN). Study the morphology of the suprascapular notch and the suprascapular transverse ligament based on MRI, variations in shape and dimensions of the suprascapular notch. A group of 100 patients underwent MRI examination of the scapular region through the period from 10th July 2019 to 15th Feb 2020. Different morphological types of the suprascapular notch were encountered in the study, the most common type was type III, while type I was less common in the study. The symmetry of the morphological feature of SN bilaterally was seen in 51% of the cases. Conclusively, the symmetry of the suprascapular notch is not a constant feature bilaterally.

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.