Introduction
Severe glenoid bone loss in reverse total shoulder arthroplasty presents significant challenges with high failure rates with bone grafting. Custom glenoid components have been reported to be a viable short term solution to with these large bone defects. However, strengths and limitation of using these implants has not been previously described. The purpose of this study was to evaluate the clinical and radiographic outcomes of reverse shoulder arthroplasty using a custom-made glenoid baseplate and to report the benefits and limitations of the use of these implants.
Material & Methods: the years 2017 and 2022 we implanted 18 custom RTSA in 18 patients with severe glenoid bone loss. 11 implants were in patients with failed previous arthroplasty and 7 were primary procedures. Complications were recorded for all patients. All patients underwent preoperative and postoperative physical examinations and radiographs. Of these 18 patients, 9 were available for 2 year follow up and also had repeated physical examinations, radiographs, and PROM’s.
Results
and Discussion: Of the original 25 patients identified for a custom glenoid component, 4 were unable to have the procedure. At the time of surgery there were 3 implants which did not fit the glenoid, and as a last resort all had pre-made RSA components inserted. Two implants were inserted but did not have complete seating in the glenoid. For this group of 5 patients the length of time from CT scan to inability to implant of the glenoid components averaged 7.3 months (range 5 to 10.7 months), compared to 5.1 months of those implanted with no difficulty. There were 5 intra-operative complications including 3 greater tuberosities fractures, 1 scapular spine fracture and 1 medial calcar of proximal humerus fracture. Of the 9 patients with a minimum of 2 year follow there was not radiographic baseplate failure or loosening in any patients. For the patients with a minimum of 2 years follow-up, there were statistically significant and minimal clinically important difference (MCID) changes from preoperatively to postoperatively for all patients for the VAS for pain, all of the PROM’s, and range of motion in abduction, internal rotation up the back, and external rotation at 90 degrees of elevation (p<0.01).
Conclusion
While custom glenoid components show promise in the treatment of significant glenoid bone loss, they are not without their challenges. This study found that a prolonged time of over 6 months between CT scanning to device implantation resulted in bone loss which rendered the implants not usable. However, when the device does fit the glenoid, satisfactory short term results can be achieved.