Foramen escapular osificado en una muestra poblacional colombo-chilena / Ossified scapular foramen in a Colombian-Chilean population sample

RESUMEN: Ocasionalmente la incisura escapular puede ser reemplazada por un foramen óseo producto de la osificación del ligamento transverso superior de la escápula. Esta formación ósea se considera un factor precipitante de la compresión del nervio supraescapular. Ciento noventa y cinco escápulas de individuos adultos pertenecientes a osteotecas de universidades de Colombia (114 escápulas) y de Chile (81 escápulas), fueron estudiadas macroscópicamente para determinar la presencia de un foramen escapular óseo. Ambas escápulas de un mismo individuo colombiano (1,75 % del total) presentaban el foramen escapular y una escápula izquierda (1,23 %) presentaba esta formación en un individuo chileno. La prevalencia de la osificación del ligamento transverso superior de la escápula es muy variable en los distintos estudios y tiende a situarse inferior al 10 %, sin embargo, puede constituirse en un factor de riesgo debido al atrapamiento o compresión del nervio supraescapular, hecho conocido como neuropatía supraescapular.

SUMMARY: Occasionally the scapular notch can be replaced by a bony foramen product of the ossification of the superior transverse scapular ligament. This bone formation is considered a precipitating factor for compression of the suprascapular nerve. One hundred and ninety-five adult scapulae from Colombian (114 scapulae) and Chilean (81 scapulae) university osteotheques were studied macroscopically to determine the presence of a bony scapular foramen. Both scapulae of the same Colombian individual (1.75% of the total) presented the scapular foramen and one left scapula (1.23%) presented this formation in a Chilean individual. The prevalence of ossification of the superior transverse scapular ligament is highly variable in the different studies and tends to be less than 10%; however, it can become a risk factor due to entrapment or compression of the suprascapular nerve, a fact known as suprascapular neuropathy.

Positioning of the metaglene in reverse shoulder arthroplasty: deltopectoral versus anterosuperior approach: a prospective randomized trial.

BACKGROUND: The primary objective of this study was to determine whether there are differences in metaglene positioning related to the approach used (deltopectoral vs. anterosuperior) in primary reverse shoulder prosthesis (reverse shoulder arthroplasty) implantation. The hypothesis was that there would be no differences in metaglene positioning between the 2 approaches. METHODS: A prospective randomized trial was designed to evaluate metaglene positioning in primary reverse shoulder arthroplasty. The patients included were allocated to either the deltopectoral approach (group I) or the anterosuperior approach (group II). Glenosphere overhang and glenosphere tilt were assessed using the methods described by Lévigne et al, Simovitch et al, and Kempton et al, and the beta angle was assessed as described by Maurer et al. The functional outcome was assessed with the Constant score at 2 years' follow-up. Scapular notch development and complication rates were also recorded. RESULTS: A total of 98 patients (77 women and 21 men) were randomized and allocated to group I (49 patients) or group II (49 patients). The mean age of the patients was 74.4 years (standard deviation, 6.3 years). Glenosphere overhang did not show significant differences between groups (6.5 mm in group I vs. 6.1 mm in group II by the Lévigne method, P = .482; 2.2 mm in group I vs. 2.1 mm in group II by the Simovitch method, P = .08). Glenosphere tilt was significantly different between groups (94.6° in group I vs. 86.8° in group II by the Lévigne method, P < .001; 125.9° in group I vs. 119.4° in group II by the Kempton method, P = .002). This was also the case for the prosthesis-scapular neck angle (94.6° in group I vs. 86.8° in group II, P < .001). Moreover, the postoperative beta angle was significantly different between groups (78.6° in group I vs. 73.8° in group II, P = .001). No significant differences were noted in terms of functional outcomes as measured with the Constant score (P = .16). No significant differences between groups were noted relative to scapular notch development and the overall complication rate. DISCUSSION: The deltopectoral and anterosuperior approaches do not differ relative to the craniocaudal positioning of the metaglene, but a slight superior tilt can be expected when using the anterosuperior approach. Both approaches yield comparable functional outcomes, scapular notch development, and complication rates at 2 years' follow-up.

Can small glenospheres with eccentricity reduce scapular notching as effectively as large glenospheres without eccentricity? A prospective randomized study.

BACKGROUND: The objective of this study was to analyze whether small glenospheres with eccentricity were comparable to large glenospheres in scapular notch development. METHODS: This prospective randomized study included 82 patients who had undergone a reverse shoulder arthroplasty with a 2-year follow-up period. After randomization, 43 patients were allocated to receive a 42-mm glenosphere and 39 patients were allocated to receive a 38-mm glenosphere with 2 mm of eccentricity. Scapular notch development was defined after examination of an anteroposterior radiograph at the end of follow-up. Functional outcomes were recorded using the Constant score before surgery and at the end of follow-up. RESULTS: Scapular notch development was present in 16.6% of patients who received a 42-mm glenosphere and 34.2% of patients who received a 38-mm eccentric glenosphere. No significant difference was found between the groups with the number of cases available (P = .07). Functional outcomes significantly increased from preoperatively to postoperatively in both groups, with no significant difference found between them (P = .77). The mean glenosphere overhang measure was 6.3 mm in patients with a 42-mm glenosphere and 6.0 mm in those with a 38-mm eccentric glenosphere (P = .68). No significant differences were noted between patients with a scapular notch and patients without a scapular notch in terms of functional outcomes. DISCUSSION: Small glenospheres with eccentricity fared slightly worse than large glenospheres regarding scapular notch development, even though no significant differences were noted. Functional outcomes were comparable between the 2 designs.

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

OBJECTIVE: The aim of our paper is to present a rare variation of the suprascapular vein, its incidence and clinical significance. CASE REPORT: A rare case of a double suprascapular vein was observed in a digitalized human cadaver on Anatomage Table 5.0. The vein divided into two branches, one passing over the transverse scapular ligament, while the other one coursed underneath the ligament, inside the notch. CONCLUSION: This variation has major clinical importance as it is associated with the appearance of Suprascapular nerve entrapment syndrome.

Geometric modification of the humeral position after total reverse shoulder arthroplasty: what is the optimal lowering of the humerus?

BACKGROUND: The main mechanical effect after reverse shoulder arthroplasty (RSA) is the lowering of the glenohumeral rotation center. The optimal value of the humeral lowering after RSA is still debated. The main objective of our study was to determine the lowering and medialization of the humerus and to correlate these parameters with short-term functional results. MATERIALS AND METHODS: The study included 70 patients with complete radiographic and clinical data. A multivariate analysis was used to compare the clinical and radiographic outcomes with the humeral lowering. RESULTS: The mean humeral lowering was 25.4 mm (range, 6-38 mm), and the mean medialization was 9.2 mm (range, 0-20 mm). Humeral lowering significantly influenced active forward elevation and the rate of scapular notching. DISCUSSION: The best clinical results and the lowest incidence of scapular notching were found after a lowering of more than 24 mm in our series. We recommend humeral lengthening of at least 24 mm after implanting a total reverse shoulder prosthesis.

Morphometry and variations of the human suprascapular notch.

AIM: The present study proposes a simple method to study variations in shape and dimensions of suprascapular notch, to classify different types and subtypes of notch and to measure the thickness of superior transverse scapular bar (ossified superior transverse ligament of scapula). MATERIAL AND METHODS: Seven hundred and twenty-eight dried scapulae were observed, examined and studied in detail. Scapulae with suprascapular notch, with suprascapular foramen having varying degree of ossification in the form of transverse scapular bar were included in the present study. Measurements of suprascapular notch and superior transverse scapular bar were taken with the help of digital vernier calliper and recorded in millimetres. The superior transverse diameter, inferior transverse diameter, depth, maximum thickness of suprascapular notch and thickness at lateral and medial end of transverse scapular bar, mean thickness of superior transverse scapular bar were recorded. The data was analyzed statistically. OBSERVATIONS AND RESULTS: We observed five types of notch in scapulae, type I: without a discrete notch (ill defined), 25 (3.43%); type II: a "V" shaped notch, 192 (26.37%); type III: "U" shaped notch, 383 (52.60%); type IV: inverted "V" shaped notch, 28 (3.84%); type V with absent suprascapular notch: 6 (0.82%). Type II and type III were again subclassified into subtypes (a, b, c and d) on the basis of depth of notch. Scapulae with superior transverse scapular bar (n=94, 12.91%) were classified according to variation in mean thickness of transverse scapular bar (MTSB). CONCLUSION: This study will help clinicians to correlate suprascapular nerve entrapment with a specific type of suprascapular notch and notch with ossified transverse scapular ligament.

The influence of humeral head inclination in reverse total shoulder arthroplasty: a systematic review.

BACKGROUND: Humeral component inclination may play an important role in implant stability and the incidence of scapular notching in reverse total shoulder arthroplasty (RTSA). This study was conducted to determine if a difference exists between RTSA prostheses with a 135° vs 155° humeral component inclination angle with respect to dislocation rates and scapular notching rates. We hypothesized that the rate of dislocation would be significantly higher with the 135° inclination design and that the rate of scapular notching would be significantly higher with the 155° inclination design. METHODS: A systematic review was registered with PROSPERO and performed with Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines using 3 publicly available free databases. Therapeutic clinical outcome investigations reporting the number of dislocations, number of patients with scapular notching, and postoperative range of motion after RTSA with levels of evidence I to IV were eligible for inclusion. All study and subject demographics were analyzed. Statistics were calculated using 2-proportion z tests. RESULTS: Thirty-eight studies including 2222 shoulders (average age, 70.3 ± 3.91 years; 67% female) undergoing RTSA were included. Of these, 1762 (79.3%) used the 155° inclination prosthesis and 460 (20.7%) used the 135° inclination prosthesis with a lateralized glenosphere. The rate of scapular notching was 2.83% in the 135° group and 16.80% in the 155° group (P < .0001, z = -7.7107). The rate of dislocation was 1.74% in the 135° group and 2.33% in the 155° group (P = .4432, z = -0.7669). CONCLUSIONS: Our systematic review of 38 studies and 2222 shoulders found that the rate of scapular nothing was significantly higher with the 155° prosthesis than with the 135° prosthesis with a lateralized glenosphere, with no difference in dislocation rates between prostheses.