Accurate component placement in shoulder arthroplasty is crucial for avoiding complications, achieving superior biomechanical performance and optimizing functional outcomes. Shoulder and elbow surgeons have explored various methods to improve surgical understanding and precise execution including preoperative planning with 3D computed tomography (CT), patient-specific instrumentation (PSI), intraoperative navigation, and mixed reality (MR). 3D preoperative planning facilitated by CT scans and advanced software, enhances surgical precision, influences decision-making for implant types and approaches, reduces errors in guide pin placement, and contributes to cost-effectiveness. Navigation demonstrates benefits in reducing malpositioning, optimizing baseplate stability, improving humeral cut, and potentially conserving bone stock, although challenges such as varied operating times and costs warrant further investigation. The personalized patient care and enhanced operational efficiency associated with PSI are not only attractive for achieving desired component positions but also hold promise for improved outcomes in complex cases involving glenoid bone loss. Augmented reality (AR) and virtual reality (VR) technologies play a pivotal role in reshaping shoulder arthroplasty. They offer benefits in preoperative planning, intraoperative guidance, and interactive surgery. Studies demonstrate their effectiveness in AR-guided guidewire placement, providing real-time surgical advice during reverse total shoulder arthroplasty (RTSA). Additionally, these technologies show promise in orthopedic training, delivering superior realism and accelerating learning compared to conventional methods.

Reverse total shoulder arthroplasty (RTSA) is the standard of care for patients with glenohumeral osteoarthritis and rotator cuff deficiency. Preoperative RTSA planning based on medical images and patient-specific instruments has been established over the last decade. This study aims to determine the effects of using augmented reality-assisted intraoperative navigation (ARIN) for baseplate positioning in RTSA compared to preoperative planning. It is hypothesized that ARIN will decrease deviation between preoperative planning and postoperative baseplate positioning. Moreover, ARIN will decrease deviation between the (senior) more (>50 RTSAs/yr) and less experienced (junior) surgeon (5-10 RTSAs/yr). Preoperative CT scans of 16 fresh-frozen cadaveric shoulders were obtained. Baseplate placements were planned using a validated software. The data were then converted and uploaded to the augmented reality system (NextAR; Medacta International). Each of the 8 RTSAs were implanted by a senior and a junior surgeon, with 4 RTSAs using ARIN and 4 without. A postoperative CT scan was performed in all cases. The scanned scapulae were segmented, and the preoperative scan was laid over the postoperative scapula by the nearest iterative point cloud analysis. The deviation from the planned entry point and trajectory was calculated regarding the inclination, retroversion, medialization (reaming depth) and lateralization, anteroposterior position, and superoinferior position of the baseplate. Data are reported as mean ± standard deviation (SD) or mean and 95% confidence interval (CI). P values < .05 were considered statistically significant. The use of ARIN yielded a reduction in the absolute difference between planned and obtained inclination from 9° (SD: 4°) to 3° (SD: 2°) (P = .011). Mean difference in planned-obtained inclination between surgeons was 3° in free-hand surgeries (95% CI: -4 to 10; P = .578), whereas this difference reduced to 1° (95% CI: -6 to 7, P = .996) using ARIN. Retroversion, medialization (reaming depth) and lateralization, anteroposterior position, and superoinferior position of the baseplate were not affected by using ARIN. Surgical duration was increased using ARIN for both the senior (10 minutes) and junior (18 minutes) surgeon. The implementation of ARIN leads to greater accuracy of glenoid component placement, specifically with respect to inclination. Further studies have to verify if this increased accuracy is clinically important. Furthermore, ARIN allows less experienced surgeons to achieve a similar level of accuracy in component placement comparable to more experienced surgeons. However, the potential advantages of ARIN in RTSA are counterbalanced by an increase in operative time.

Background: The long-term results of arthroscopic Bankart repair are poorly reported in the literature and show recurrence rates as high as 37%. However, this high failure rate is based on historical studies of patients with critical defects stabilized using older techniques. Purpose: To evaluate the long-term clinical outcomes of arthroscopic Bankart repair using a contemporary technique with a minimum of 3 suture anchors in patients with traumatic anterior instability and to assess possible risk factors for recurrent instability. Study Design: Case series; Level of evidence, 4. Methods: A total of 181 patients (182 shoulders), who underwent arthroscopic Bankart repair because of traumatic anterior instability between 2005 and 2014, were included in this study and evaluated at a minimum follow-up of 10 years. Exclusion criteria were previous shoulder surgery, additional stabilization procedures, use of 20%, off-track Hill-Sachs lesion). The primary outcome was recurrent instability. Secondary outcomes were the Subjective Shoulder Value (SSV), visual analog scale (VAS), Constant score, Western Ontario Shoulder Instability Index (WOSI), and Rowe score as well as sports activity level and return to sports. Risk factors for recurrent instability were analyzed. Results: The overall recurrence rate was 20.9% at a mean follow-up of 13.8 ± 2.8 years. Age ≤20 years at the time of surgery was associated with a higher risk of recurrence ( P = .007). The failure rate was lower in patients who underwent surgery after the first-time dislocation (8/58 [13.8%]) compared with patients who underwent surgery after multiple instability events (30/124 [24.2%]), although this was not statistically significant ( P = .108). Patients without recurrent instability had statistically significant better scores on the SSV ( P < .001), VAS for pain during movements ( P = .016), Constant score ( P = .011), WOSI ( P = .001), and Rowe score ( P < .001) compared with patients with recurrence without revision surgery. A shorter interval between the first dislocation and surgery was associated with better shoulder outcomes, despite a consistent recurrence rate. Of all patients, 97.6% returned to sports, with 69.6% returning to 90% to 100% of their preoperative sports activity. Conclusion: Arthroscopic Bankart repair resulted in a relatively high recurrence rate, despite the use of a contemporary technique, particularly in patients with >1 dislocation before surgery. While younger age and a higher number of preoperative dislocations were potential risk factors for recurrence, a shorter interval between the first dislocation and surgery was associated with improved clinical outcomes. Therefore, patients with a high risk of redislocations should be considered for early soft tissue stabilization, while additional procedures such as remplissage should be performed for those with nonmodifiable high-risk factors.

Posterior shoulder instability (PSI) is less common than anterior shoulder instability, accounting for 2–12% of total shoulder instability cases. However, a much higher frequency of PSI has been recently indicated, suggesting that PSI accounts for up to 24% of all young and active patients who are surgically treated for shoulder instability. This differentiation might be explained due to the frequent misinterpretation of vague symptoms, as PSI does not necessarily present as a recurrent posterior instability event, but often also as mere shoulder pain during exertion, limited range of motion, or even as yet asymptomatic concomitant finding. In order to optimize current treatment, it is crucial to identify the various clinical presentations and often unspecific symptoms of PSI, ascertain the causal instability mechanism, and accurately diagnose the subgroup of PSI. This review should guide the reader to correctly identify PSI, providing diagnostic criteria and treatment strategies.

Background: Patients with a periprosthetic joint infection (PJI) of the shoulder, who fail to undergo reimplantation in an attempted two-stage exchange seem to be neglected in the current literature. The aim of this study was to assess the clinical course of patients after the first stage in the process of an attempted two-stage exchange for shoulder PJI. Methods: After a retrospective review of our institutional database between 2008 and 2018, 49 patients, who were treated with an intended two-stage exchange for shoulder PJI, were identified. Patients’ demographics, laboratory and health status parameters, along with records of clinical outcome were collected. The primary outcome measurements analyzed were infection eradication, successful reimplantation, and patient survival. Results: Reimplantation was completed in only 35 (71%) of 49 cases and eradication of infection was achieved in 85.7% of patients with successful reimplantation after a mean follow-up duration of 5.1 years (1.1 to 10.2 years). Reasons for failure to reimplant were premature death in 36%, high general morbidity in 29%, satisfaction with the current status in 21%, or severe infection with poor bone and soft tissues in 14% of the patients. Of the 14 cases without reimplantation, eradication rate of infection was 57% after a mean follow-up of 5 years (2.6 to 11 years). The overall mortality rate of the entire cohort was 25% at the latest follow-up and 10% within ninety days after implant removal. Patients who deceased or did not undergo reimplantation during the follow-up were significantly older and had a significantly higher Charlson comorbidity index (CCI). Conclusions: While the two-stage exchange arthroplasty can lead to high rates of infection eradication, a considerable subset of patients never undergoes the second stage for a variety of reasons. Shoulder PJI and its treatment are associated with a high risk of mortality, especially in patients with older age and higher CCI.

Introduction: The risk of prosthetic joint infection (PJI) in mega-prosthesis for malignancy is increased compared with non-tumor cases. While several studies describe PJI in tumor-related arthroplasty, prospective studies comparing infection characteristics among different joints are limited. The present study analyzes mega-arthroplasty for hip, knee, and shoulder malignancy and compares the epidemiology, diagnosis, microbe spectrum, treatments, and outcomes between the different entities. Methods: The retrospective inclusion criteria were as follows: (1) mega-arthroplasty (2) in the hip, knee, or shoulder joint and a total femur arthroplasty (3) following a malignant bone tumor or metastasis (4) between 1996 and 2019. All included patients were prospectively followed and invited for a renewed hospital examination, and their PJI characteristics (if identified) were analyzed using both retrospective as well as newly gained prospective data. A PJI was defined according to the Infectious Disease Society of America (IDSA) and re-infection was defined according to the modified Delphi Consensus criteria. Results: In total, 83 cases of tumor mega-arthroplasty at a mean follow-up of 3.9 years could be included (32 knee, 30 hip, and 19 shoulder cases and 2 cases of total femur arthroplasty). In total, 14 PJIs were identified, with chondrosarcoma in 6 and osteosarcoma in 3 being the leading tumor entities. Knee arthroplasty demonstrated a significantly higher rate of PJI (p = 0.027) compared with hips (28.1% vs. 6.7%), while no significant difference could be found between the knee and shoulder (10.5%) (p = 0.134) or among shoulder and hip cases (p = 0.631). The average time of PJI following primary implantation was 141.4 months in knee patients, 64.6 in hip patients, and 8.2 months in shoulder patients. Age at the time of the primary PJI, as well as the time of the first PJI, did not show significant differences among the groups. Thirteen of the fourteen patients with PJI had a primary bone tumor. Statistical analysis showed a significant difference in the disadvantage of primary bone tumors (p = 0.11). While the overall cancer-related mortality in the knee PJI group (10%) was low, it was 50% in the hip and 100% in the shoulder group. Conclusion: The risk of PJI in knee tumor arthroplasty is significantly increased compared with hips, while cancer-related mortality is significantly higher in hip PJI cases. At the same time, mega-prostheses appear to be associated with a higher risk of infection due to a primary bone tumor compared with metastases. The study confirms existing knowledge concerning PJI in tumor arthroplasty, while, being one of the few studies to compare three different joints concerning PJI characteristics.