Scapular notching in reverse shoulder arthroplasty. Relationship with surgeon̈s experience and clinical outcomes

BACKGROUND

Scapular Notching is a problem frequently seen in Reverse shoulder arthroplasties (RSAs), produced by a collision between the humeral component and the scapula. The main objective of this study is to analyze whether this problem decreases with the surgeons experience. As secondary objectives, assessing whether there is a relationship between its appearance and the clinical and functional outcome of patients.

METHODS

We retrospectively reviewed 101 patients with 105 RSAs; we analyzed complications, focusing on scapular notching. Main follow-up time was 36 month (12-72). The clinical and functional outcomes were evaluated with the Constant scale and the QuickDash questionnaire.

RESULTS

Forty-two patients (40%) had some degree of scapular notching. Of these, 25 patients had grade I, 14 had grade II and 3 had grade III notching. The average postoperative Constant score for the entire series was 60.72. A tendency toward a reduced incidence of notching was observed with increasing numbers of operated cases and experience of the surgeon (p=0.04). In the group of patients who had notching, the average postoperative Constant score was 56, and in the group that developed notching, the average score was 63. Patients with notching had significantly lower pain scores (p=0.012).

CONCLUSIONS

Scapular notching is a common problem of RSA. In RSA, the experience of the surgeon reduces the appearance of problems and complications. Scapular notching is related to poorer clinical outcomes with respect to pain.

Anthropometrical study of the human glenoid in a normal Spanish population

OBJECTIVE

To evaluate the size of the glenoid in a southern Spanish population, to compare it with previous results from other populations and determine the size of the implants that are marketed for shoulder arthroplasty.

MATERIAL AND METHODS

Between January 2015 and December 2017, an anthropometrical study of the human glenoid was performed using computed axial tomography scans (CT) of 154 patients over 30 years old. The glenoid dimensions were analysed 3-dimensionally using 2mm interval thicknesses, determining the average height and width of the glenoid. The upper point of the glenoid geometry was determined as the supraglenoid tubercle of the ovoid glenoid surface, where the long head of the biceps tendon is thought to originate. The lower point was then positioned at the furthest point from the upper point on the glenoid contour. Anterior and posterior points were determined such that the 3-dimensional anterior-posterior distance was maximized on the plane perpendicular to the upper-lower axis. Sex differences and correlations between sides and among the respective parameters in the glenohumeral dimensions were also evaluated.

RESULTS

The glenoid had an average height of 28.78mm and width of 20.27mm. The values were significantly different between the men and the women, being greater in the men. The glenoid size is well correlated with the patient's size. Direct correlations exist between the glenoid height and width and the glenoid size and the patient's height. The available metaglenoids currently on the market are no bigger than 25-24mm.

CONCLUSION

In comparison, the southern Spanish population have a glenoid size similar to the Caucasian population, but smaller than that of the American population. The data shown could be useful to improve the design of shoulder prostheses for the southern Spanish population.

Reverse shoulder arthroplasty due to glenoid bone defects

OBJECTIVE

Reverse shoulder arthroplasty is becoming a useful tool for many diseases of the shoulder. Any severe glenoid bone defect may affect the fixing of the glenoid component. The aim of this paper is to evaluate the medium-term outcomes of reverse shoulder arthroplasty associated with a glenoplasty.

MATERIALS AND METHODS

A retrospective study was conducted on 5 patients from our hospital, selected due to glenoid defects of different etiology. All of them where treated with reverse shoulder arthroplasty associated with glenoplasty with bone graft.

RESULTS

The minimum follow-up was one year (mean 30.4 months). All grafts were radiologically integrated, with no signs of resorption or necrosis being observed. At 12 months, the Constant score was 66.75 and the mean EVA score was 1.

DISCUSSION

Glenoplasty surgery is technically demanding for restoring original bone size in patients with glenoid structural defects, enabling a reverse shoulder arthroplasty to be implanted. Thus improving both the function and clinical outcomes in selected patients with glenohumeral pathology and providing them with a solution.