Glenoid revision is best treated with glenoid implants: Opposes

Glenoid component loosening is a common cause of failure for anatomic total shoulder arthroplasty. Revision options include reimplantation of an anatomic total shoulder, conversion to a reverse shoulder arthroplasty, or bone graft of the glenoid defect alone. In the presence of an intact rotator cuff with significant glenoid bone loss, the most predictable revision option is bone graft of the glenoid defect alone. Recent studies have demonstrated good clinical outcomes and a lower complication and re-revision rate with bone graft alone compared to attempted glenoid component reimplantation.     

Antibiotic-loaded bone cement vs. plain cement as an infection prophylaxis in primary elective shoulder arthroplasty

HypothesisThe use of antibiotic-loaded bone cement (ABC) in the setting of revision arthroplasty for deep infections is a broadly accepted practice. However, its use in the setting of primary arthroplasty continues to be controversial with few studies assessing the efficacy of ABC for primary total shoulder arthroplasty (TSA). The purpose of this study was to determine whether the use of ABC in primary TSA is associated with a difference in the risk of deep infections.MethodsA retrospective cohort study was conducted using data from a United States integrated health-care system’s shoulder arthroplasty registry. Patients aged ≥18 years who underwent primary elective anatomic TSA for osteoarthritis or reverse TSA (RTSA) for rotator cuff arthropathy with implanted cement information were included in the study (2009-2020). We compared patients that received ABC to those who received plain cement and are at risk of revision due to deep infection within 5 years of follow-up using Cox proportional hazard regression weighted with the inverse propensity score, stratified by procedure type.ResultsThe study sample included 6409 TSAs for osteoarthritis and 779 RTSAs for rotator cuff arthropathy performed by 198 surgeons at 58 hospitals. In the TSA group, 20% received ABC; the cumulative infection probability at 5 years of follow-up was 0.5% and 0.6% for the ABC and plain cement groups, respectively. After covariate adjustment, no significant difference in infection risk was found (hazard ratio = 0.72, 95% confidence interval = 0.43-1.21, P = .216). In the RTSA group, 19% received ABC; the cumulative infection probability at 5 years of follow-up was 2.7% and 0.9% for the ABC and plain cement groups, respectively. After covariate adjustment, no significant difference in infection risk was found between the 2 cement groups (hazard ratio = 1.47, 95% confidence interval = 0.66-3.26, P = .341).ConclusionIn this study of more than 7000 primary elective shoulder arthroplasties performed in patients with a standard risk of infection, antibiotic bone cement did not confer any risk-reduction for periprosthetic infection when compared to plain bone cement. Different at-risk pathogen profiles may develop with prolonged use of antibiotic bone cement.     

Managing glenoid bone loss virtual surgery—A software solution

Inaccurate placement of glenoid prosthesis in shoulder arthroplasty can lead to early loosening, instability, and failure. To address difficult glenoid morphology, patient-specific instrumentation and navigation techniques have been developed. Advanced imaging data has demonstrated utility in preoperative decision making. Cadaveric studies have subsequently shown that the application of advancing imaging and navigation can lead towards increased accuracy with prosthesis placement. Clinical trials have also shown increased accuracy with navigation and advanced imaging, but data demonstrating improved long-term outcomes and decreased complication rates is not yet available. This technology continues to evolve as a method to address glenoid bone loss and abnormal morphology.     

Effect of stress-shielding-induced bone resorption on glenoid loosening in reverse total shoulder arthroplasty

Aseptic loosening of the glenoid component is one of the main reasons for the high revision rates of reverse total shoulder arthroplasty (RTSA). It has been reported that the bulky implant designs may lead to stress shielding. However, it is uncertain whether the shielding effect is severe enough to lead to bone resorption and glenoid loosening. The purpose of this study was to evaluate the level of stress-shielding and assess whether bone resorption plays a role in aseptic glenoid loosening following RTSA. A cadaveric in vitro test model was used to validate a finite element model (FEM) of the scapula. The FEM of the scapula, incorporating adaptive bone remodeling algorithms, was used to predict changes in postoperative bone density after RTSA. Changes in bone strength after implantation were also analyzed. The strain values predicted from the FEM of the scapula were in agreement with the in vitro measurements. Analysis of postoperative bone adaptation revealed that strain-induced bone resorption began at the peg of the implant and around the resected bone surface and then gradually expended to the peripheral regions. The bone strength also reduced postoperatively and appeared particularly around the implant peg. Strain-induced bone resorption is a likely source of the bone loss commonly observed in RTSA. The finite element glenoid bone remodeling simulation may be used as a tool to evaluate glenoid implant design.     

Systematic Review and Meta-Analysis of Locked Posterior Dislocation of the Shoulder Treated with Shoulder Arthroplasty: Improved Outcomes for Total Shoulder Arthroplasty are Associated with Increased Age

Locked shoulder dislocations account for up to 5% of shoulder dislocations. These relatively rare injuries are characterized by dislocation of the humeral head from the scapular glenoid cavity with the humeral head incarcerated on the glenoid in a “locked” fashion. Diagnosis is often delayed because of the complexity of clinical presentation and subtle radiographic findings, resulting in locking of the humeral head out of the glenoid cavity with severe functional deficits. Most commonly, there are bony injuries to the glenoid and humeral head that engage and prevent closed reduction. Since few patients present with this injury, evidence-based treatment guidelines have not been established. The objective of this review is to assess postoperative outcomes following shoulder arthroplasty for locked posterior shoulder dislocations (LPSD) to guide best practices for treatment. This systematic review was conducted following PRISMA guidelines, searching the PubMed and Web of Science databases for original articles assessing outcomes following arthroplasty for locked posterior shoulder dislocations. Seven publications that evaluated 102 patients were included. Additionally, nine case studies were included, assessing 20 shoulder arthroplasties. Overall, the analysis demonstrated significant improvement in shoulder pain following total shoulder arthroplasty (TSA) (P = 0.0003). Older operative patient ages for TSA resulted in significantly improved modified Neer outcomes scores and patient satisfaction compared to younger patients (P = 0.047). A positive correlation was noted for the duration of dislocation and necessity for revision surgery following hemiarthroplasty (HSA) and TSA combined and TSA separately. The risk ratios assessing the incidence of postoperative complications (RR = 0.56, 95% CI = 0.28–1.11) and necessity for revision surgery (RR = 0.58, 95% CI = 0.24–1.39) were insignificant but noted outcomes favoring TSA. Data from the included studies show that both TSA and HSA are efficacious at treating locked posterior shoulder dislocation. Postoperative outcomes following TSA versus HSA are similar. TSA may be a more efficacious surgical treatment in elderly patients, with improved outcomes and patient satisfaction scores compared to younger patients. Early diagnosis and treatment of posterior locked dislocations may lead to reduced postoperative complications and revision surgery, signaling the importance of proper injury investigation and early treatment. The role of RSA in the management of locked posterior shoulder dislocation remains to be determined, as there is insufficient clinical outcome data currently in the literature.     

Shoulder arthroplasty in patients with ipsilateral hemiparesis: a safe and durable procedure? A case series

HypothesisShoulder arthroplasty is a safe and durable procedure that provides pain relief, improved range of motion (ROM), and minimal complications for shoulder pain and dysfunction in patients with ipsilateral hemiparesis.MethodsThis is a retrospective review of all adult patients who underwent primary reverse total shoulder arthroplasty (RSA) or total shoulder arthroplasty (TSA) in the hemiparetic upper extremity at a single quaternary care academic medical center from 1988 to 2019. Patients were excluded if their neurologic insult was secondary to a spinal-cord injury, cerebral palsy, or inflammatory arthritis, if they underwent a hemiarthroplasty, if they exhibited mild hemiparesis (Medical Research Council Scale of ≥4), or if they had less than 30 days of radiographic follow-up. The primary clinical outcome was revision surgery for any reason. The secondary clinical outcomes included pain using the visual analog scale, ROM via active-assisted manual muscle testing (AAROM), and postoperative complications. The primary radiographic outcome was implant lucency using a standard scale.ResultsA total of 5 shoulders in 5 patients were included, 4 RSAs and 1 TSA with a mean clinical follow-up of 6.2 years (range: 1.42-14.2 years) and mean radiographic follow-up of 3.7 years (range: 31 days-13.5 years). No patient underwent revision surgery. The mean visual analog scale score significantly improved from 7.6 to 1.4 at the last follow-up (P = .005). The mean forward elevation AAROM improved from 27° preoperatively to 88° at the last follow-up (P = .015). There was no significant difference in external rotation at the last follow-up (P = .105). One patient had asymptomatic grade 1 glenoid component lucency with superior subluxation of the humerus after undergoing TSA at a final follow-up of 4.5 years. No other complications were reported.ConclusionShoulder arthroplasty is a durable procedure that provides pain relief, improved AAROM, and minimal complications in patients with ipsilateral hemiparesis. The increase in active-assisted forward elevation ROM can improve caregiver ease with hygiene and dressing. Patients in this study who underwent RSA did not have subsequent glenohumeral dislocation. Larger numbers of patients would be required for adequate power analysis regarding instability in this cohort of patients who may be at risk; our small series did not identify any instability events.Level of evidenceLevel IV; Treatment Study