Concept: Suprascapular notch
A unique anatomical variation of the suprascapular notch was discovered in one scapula from 610 analyzed by three-dimensional CT reconstruction. Two bony bridges were found, converting it into a double suprascapular foramen, in the left upper extremity of an 56-year-old Caucasian female. This variation might be a risk factor for suprascapular nerve entrapment. Suprascapular nerve running through inferior suprascapular foramen was discovered. Suprascapular vessels passed through superior suprascapular foramen (artery lay medially and vein laterally). A new hypothesis of double suprascapular foramen formation (mechanism of creation) is presented based on recent anatomical findings (e.g., the discovery in 2002 of the anterior coracoscapular ligament). Knowledge of the anatomical variations described in this study should be helpful in arthroscopic and open procedures at the suprascapular region and also confirms the safety of operative decompression for the suprascapular nerve.
The suprascapular notch is the most common site of suprascapular nerve entrapment, which can manifest in disability and pain of the upper limb. Here, we present three cases of a very rare anatomical variation in the suprascapular region: the coexistence of the suprascapular notch and the suprascapular foramen. The variation was found during radiological and anatomical investigations. The suprascapular foramen was situated inferior to the suprascapular notch. A bony bridge lay between them, likely created by an ossified anterior coracoscapular ligament (ACSL). This anatomical variation probably increased the risk of suprascapular nerve entrapment by nerve irritation of the bony margins during passsage through the foramen and by a lack of the elasticity that the ACSL normally demonstrates. Also, a bony bridge passing through the middle part of the suprascapular notch reduces the space available for nerve passage (bony bridge decreases the space by about 36.5-38.6 %). One patient who underwent the radiological study had typical symptoms of suprascapular nerve entrapment. Based on his medical history and the presence of this rare variation of the suprascapular notch at the suprascapular region we suspect this neuropathy.
BACKGROUND: Better knowledge of the suprascapular notch anatomy may help to prevent and to assess more accurately suprascapular nerve entrapment syndrome. Our purposes were to verify the reliability of the existing data, to assess the differences between the two genders, to verify the correlation between the dimensions of the scapula and the suprascapular notch, and to investigate the relationship between the suprascapular notch and the postero-superior limit of the safe zone for the suprascapular nerve. METHODS: We examined 500 dried scapulae, measuring seven distances related to the scapular body and suprascapular notch; they were also catalogued according to gender, age and side. Suprascapular notch was classified in accordance with Rengachary’s method. For each class, we also took into consideration the width/depth ratio. Furthermore, Pearson’s correlation was calculated. RESULTS: The frequencies were: Type I 12.4%, Type II 19.8%, Type III 22.8%, Type IV 31.1%, Type V 10.2%, Type VI 3.6%. Width and depth did not demonstrate a statistical significant difference when analyzed according to gender and side; however, a significant difference was found between the depth means elaborated according to median age (73 y.o.). Correlation indexes were weak or not statistically significant. The differences among the postero-superior limits of the safe zone in the six types of notches was not statistically significant. CONCLUSIONS: Patient’s characteristics (gender, age and scapular dimensions) are not related to the characteristics of the suprascapular notch (dimensions and Type); our data suggest that the entrapment syndrome is more likely to be associated with a Type III notch because of its specific features.
The shape and size of the suprascapular notch (SSN) is one of the most important risk factors in suprascapular nerve entrapment. The aim of the study was to perform a morphological study of SSN variations.
A proposal for classification of the superior transverse scapular ligament: variable morphology and its potential influence on suprascapular nerve entrapment
- Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.]
- Published almost 8 years ago
BACKGROUND: The suprascapular region is the most common site of suprascapular nerve entrapment. The aim of the present study was to determine the morphologic variation of the superior transverse scapular ligament (STSL) and measure the reduction in size of the suprascapular opening. Other structures that might be potentially significant during open and arthroscopic procedures in this region are also described. MATERIALS AND METHODS: The study used 86 randomized formalin-fixed human cadaveric shoulders. After dissection of the suprascapular region, the following measurements were defined and collected for every STSL: length, proximal width, distal width, and thickness at the proximal and distal ends. Measurements were also taken of the area of the suprascapular opening (aSSO) and the middle width of the suprascapular opening (mwSSO). RESULTS: Three types of STSL may be distinguished: a fan-shaped type (54.6%), a band-shaped type (41.9%), and a bifid type (3.5%). Statistically significant differences between the specimens with fan-shaped and band-shaped types of STSL were observed in aSSO and mwSSO of the suprascapular opening. Anterior coracoscapular ligaments (ACSL) were present in 44 of 86 shoulders. The aSSO and mwSSO were smaller in specimens with an ACSL than in those without; however, this difference was only significant in the band-shaped type of STSL. CONCLUSION: Knowledge of the morphologic variations of STSL presented in this study is important for better understanding the possible anatomic conditions that can promote suprascapular nerve entrapment and should be taken into particular consideration during surgical and arthroscopic procedures around the suprascapular notch.
The vascular anatomy at the spinoglenoid and suprascapular notches appears to be more variable than previously thought. In patients presenting with signs of suprascapular nerve compression, vascular causes must be considered. Especially when considering percutaneous or arthroscopic treatment, awareness of these entities may help to guide treatment decisions, aid in identification of the anatomy, and prevent unwanted vascular insult.
Multiple versus single ultrasound guided suprascapular nerve block in treatment of frozen shoulder in diabetic patients
- Journal of back and musculoskeletal rehabilitation
- Published about 4 years ago
Suprascapular nerve block (SSNB) is used in the management of frozen shoulder. There are no evidences from the literature that can determine how many blocks and the interval between them.
Although the pathomechanism of isolated infraspinatus atrophy (ISA) in throwing sports is known to be traction, it is unclear why only some players are affected. One likely explanation is that the infraspinatus pulling force exerted by its contracture generate the compressive resultant component force (Fn) compressing the lateral trunk of the suprascapular nerve (LTSN) against the edge of scapular spine. This paper makes two key assumptions (1) the course of LTSN in relation to the scapular spine, defined as the suprascapular-scapular spine angle (SSSA) is the key individual anatomical feature influencing the Fn magnitude, and thus potentially ISA development (2) SSSA is correlated with scapular notch type.
Additional landmarks for identifying the suprascapular nerve at its entrance into the suprascapular foramen from an anterior approach would be useful to the surgeon.
Monocortical fixation of the coracoid in the Latarjet procedure is significantly weaker than bicortical fixation
- Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA
- Published about 3 years ago
A crucial step of the Latarjet procedure is the fixation of the coracoid process onto the glenoid. Multiple problems associated with the fixation have been described, including lesions of the suprascapular nerve due to prominence of the screw or bicortical drilling. The purpose of the present study was to evaluate whether monocortical fixation, without perforating the posterior glenoid cortex, would provide sufficient graft stability.