Complications of Reverse Total Shoulder Arthroplasty: A Computational Modelling Perspective

Abstract

Reverse total shoulder arthroplasty (RTSA) is an established treatment for elderly patients with irreparable rotator cuff tears, complex proximal humerus fractures, and revision arthroplasty; however, with the increasing indications for RTSA over the last decade and younger implant recipients, post-operative complications have become more frequent, which has driven advances in computational modeling and simulation of reverse shoulder biomechanics. The objective of this study was to provide a review of previously published studies that employed computational modeling to investigate complications associated with RTSA. Models and applications were reviewed and categorized into four possible complications that included scapular notching, component loosening, glenohumeral joint instability, and acromial and scapular spine fracture, all of which remain a common cause of significant functional impairment and revision surgery. The computational shoulder modeling studies reviewed were primarily used to investigate the effects of implant design, intraoperative component placement, and surgical technique on postoperative shoulder biomechanics after RTSA, with the findings ultimately used to elucidate and mitigate complications. The most significant challenge associated with the development of computational models is in the encapsulation of patient-specific anatomy and surgical planning. The findings of this review provide a basis for future direction in computational modeling of the reverse shoulder.

Patient-specific implants in reverse shoulder arthroplasty

“…(1) Meticulous care should be taken when choosing the right patients for PSI because the technology is relatively novel, and long-term outcomes remain equivocal. (2) The choice of technique to overcome glenoid bone loss must consider the needs of individual patients. Each of the relevant methods has its own strengths and limitations, and any surgical decision, be it excessive reaming, the use of an alternate centerline, bone grafting, or PSI, must be patient-centered and discussed with them.…”

“…Total shoulder arthroplasty has become more common in recent years because of its high success with excellent outcomes [ 1 ]. Reverse total shoulder arthroplasty (RTSA) reverses the ball-and-socket shoulder joint and medializes the center of the joint to enhance the function of the deltoid muscle and increase stability in rotator cuff-deficient shoulders in a semi-constrained way [ 2 ]. Since the introduction of RTSA in 1985 by Paul Grammont and its approval by the Food and Drug Administration in 2004, it has gained a massive boost in popularity, which has contributed to an increase in the incidence of shoulder arthroplasty procedures [ 1 ].…”

“…A recent study with a large population reported that RTSA has a complication rate of 16.1% [ 5 ]. Some of the most frequent complications are scapular notching, acromial fracture, instability, component loosening (humeral and glenoid), infection, and neurologic injury [ 2 , 4 , 6 , 7 ]. Glenoid component mispositioning is a common and serious complication of RTSA that requires special consideration, even in seemingly straightforward cases [ 8 ].…”

Safety and Early Results for Off-Label Use of Intranasal Calcitonin for Treatment of Nondisplaced Acromial and Scapular Spine Stress Fractures After Reverse Total Shoulder Arthroplasty

“…3 The most frequently reported complications of RSA are scapular notching, implant loosening, glenohumeral joint instability, and acromial and scapular spine stress fractures (AF/SSF). 3,4 As implant designs, techniques, and overall understanding of RSA biomechanics have improved with time, rates of many early complications, such as implant loosening and instability, have markedly decreased in recent years. Despite these advancements, the rate of AF/ SSF remains steady at 2% to 3%, 3 with some studies reporting rates as high as 7%.…”

Orientation of the Scapula in the Standing Position

“…The integration of patient-specific morphological and functional data into computer model-based planning devices is one of the major challenges and could still improve postoperative results. 9,10 The extraction of patient anatomical data is based on static threedimentional (3D) imaging in the supine position. 11 However, the scapula may have a different position depending on the position of the patient.…”