The biomechanical assessment of two stemless shoulder arthroplasty prostheses in uniformly poor-quality bone mineral density cadaveric specimens.

BACKGROUND: Stemless shoulder arthroplasty offers several advantages, such as preserving bone stock and reducing periprosthetic fracture risk. However, implant motion can deter osteointegration and increase bone resorption, where micromotion less than 0.150 mm is crucial for bony ingrowth and vital to the success of the implant. The interaction between the implant and the metaphyseal bone and its effects on stability remains unclear. Therefore, this cadaveric study aims to assess the immediate stability of two stemless prostheses in low bone density specimens. METHODS: Twenty cadaveric shoulders were used to compare the stability of two stemless shoulder implants by Zimmer-Biomet (model A) and Exactech (model B), subjected to loads of 220 N, 520 N, and 820 N to assess strain and micromotion. FINDINGS: Micromotion at 220 N load was 0.061 ± 0.080 mm and 0.053 ± 0.050 mm, and at 520 N load, 0.279 ± 0.37 mm and 0.311 ± 0.35 mm for models A and B, respectively. The estimated mean force required to achieve a 150 µm micromotion was 356 ± 116 N and 315 ± 61 N for models A and B, respectively. Motion analysis revealed distinct movement patterns for each implant, with model B demonstrating better force distribution on the bone despite no significance. INTERPRETATION: Forces over 520 N (high postoperative rehabilitation force) could hinder bone integration with prostheses due to excessive micromotion. Conversely, forces around 220 N (preconditioning loading force) are considered safe for prosthesis stability even with low bone density. These insights may caution against using stemless implants when bone density is low, and help guide clinical decisions on the duration of rehabilitation and sling use after stemless arthroplasty.

Stress shielding in stemmed reverse shoulder arthroplasty: an updated review.

BACKGROUND: Reverse shoulder arthroplasty (RSA) is popular for the treatment of degenerative glenohumeral joint disease. Bone remodeling around the humeral stem related to stress shielding (SS) has been described. This review focuses on the specific radiological characteristics, risk factors, and clinical consequences of SS in RSA. METHODS: A meticulous review was conducted of articles published between 2013 and 2023. Data on the definition, risk factors, and clinical impact of stress shielding were recorded. RESULTS: Twenty-eight studies describing 2691 patients who had undergone RSA were included. The mean age of patients ranged from 63 to 80 years with mean follow-up periods of 12 months to 9.6 years. The prevalence of SS reached up to 39% at a 2-year follow-up. Females and elderly are typically at higher risk due to osteopenia. SS was more frequent with the use of long stems(>100 mm) compared to short stems(<100 mm). Stem design, onlay or inlay, and neck-shaft-angle did not influence SS. Frontal misalignment and a high filling ratio are riskfactors for SS. Biological factors also contribute to SS, associated with scapular notching. No correlation was found between SS and clinical outcomes. CONCLUSIONS: SS is common in patients with cementless implants after RSA, especially in female and elderly patients. It can be limited by implanting stems with a low diaphyseal filling-ratio, in correct coronal alignment. Risk factors for polyethylene debris, primarily scapular notching, should be avoided. The authors found no clinical consequences of stress shielding, but longer-term follow-up studies are required to confirm these findings.

Mid- to long-term outcome of reverse total shoulder arthroplasty as revision procedure for failed hemiarthroplasty after proximal humerus fracture.

BACKGROUND: Insufficient tuberosity healing is the most common reason for poor outcome after treatment of proximal humerus fractures (PHFs) using hemiarthroplasty (HA). In these cases, revision to reverse total shoulder arthroplasty (RTSA) can improve function and reduce pain in the short term, however, long-term results remain scarce. Aim of this study was to evaluate the clinical and radiological mid- to long-term results in patients with a revision RTSA after failed HA for PHF. METHODS: In this retrospective study all patients that received a revision to RTSA after failed fracture HA between 2006 and 2018 were included. A total of 49 shoulders in 48 patients (38 female, 10 male; mean age 82 ± 9 years) were identified in our database. A total of 20 patients (17 female, 3 male; mean age was 79 ± 9 years) were available for follow-up examination after a mean time period of approximately eight years (3-14 years) after revision surgery. At final follow-up, patients were assessed using a subjective shoulder value (SSV), range of motion (ROM), visual analogue score (VAS), the Constant Score (CS) and the 12-Item Short Form Survey (SF-12). RESULTS: At final follow-up, mean CS was 55 ± 19 (19-91), VAS averaged 3 ± 3 (0-8) and mean SSV was 61 ± 18% (18-90%). Mean SF-12 was 44 (28-57) with a mean physical component summary (PCS) of 38 (21-56) and a mean mental component summary (MCS) of 51 (29-67). On average active forward flexion (FF) was 104° (10-170°), active abduction (ABD) was 101° (50-170°), active external rotation (ER) was 19° (10-30°) and active internal rotation (IR) of the lumbosacral transition was reached. Three patients presented with a periprosthetic humeral fracture after RTSA implantation and underwent a reoperation (15%) during follow-up period. CONCLUSIONS: Revision RTSA results in promising clinical results in patients after initial failed HA after PHF. A complication and reoperation rate of 15% is tolerable in consideration of satisfactory functional and psychological outcome. TRIAL REGISTRATION: Retrospectively registered.

Can ChatGPT Answer Patient Questions Regarding Reverse Shoulder Arthroplasty?

INTRODUCTION: In recent years, Artificial Intelligence (AI) has seen substantial progress in its utilization, with Chat Generated Pre-Trained Transformer (ChatGPT) emerging as a popular language model. The purpose of this study was to test the accuracy and reliability of ChatGPT's responses to frequently asked questions (FAQ) pertaining to reverse shoulder arthroplasty (RSA). METHODS: The ten most common FAQs were queried from institution patient education websites. These ten questions were then input into the chatbot during a single session without additional contextual information. The responses were then critically analyzed by two orthopedic surgeons for clarity, accuracy, and the quality of evidence-based information using The Journal of the American Medical Association (JAMA) Benchmark criteria and the DISCERN score. The readability of the responses was analyzed using the Flesch-Kincaid Grade Level. RESULTS: In response to the ten questions, the average DISCERN score was 44 (range 38-51). Seven responses were classified as fair and three were poor. The JAMA Benchmark criteria score was 0 for all responses. Furthermore, the average Flesch-Kincaid Grade Level was 14.35, which correlates to a college graduate reading level. CONCLUSION: Overall, ChatGPT was able to provide fair responses to common patient questions. However, the responses were all written at a college graduate reading level and lacked reliable citations. The readability greatly limits its utility. Thus, adequate patient education should be done by orthopedic surgeons. This study underscores the need for patient education resources that are reliable, accessible, and comprehensible. LEVEL OF EVIDENCE: IV.

Comparison between arthroplasty and non-operative treatment for proximal humeral fractures: a systematic review and meta-analysis.

Background: The clinical efficacy of reverse shoulder arthroplasty (RSA), hemiarthroplasty (HA), and non-surgical management in the treatment of proximal humeral fractures (PHFs) is inconclusive. This systematic review and meta-analysis compared the clinical outcomes of arthroplasty and non-surgical management of PHFs. Methods: The databases of PubMed, Embase, Web of Science, and Cochrane Library were searched on 5 May 2023 for studies comparing arthroplasty and non-surgical treatment of PHFs. Both randomized controlled trials (RCTs) and non-randomized controlled trials (nRCTs), were included. Standard methodological quality assessments were conducted for both types of studies. The primary outcome was the Constant-Murley Score (CMS) after surgical or non-surgical treatment. Secondary study outcomes included the visual analog scale (VAS), range of motion, and complications. All functional scores and complications were subjected to subgroup and sensitivity analyses. Results: A total of four RCTs and six nRCTs were included in this study, which provided 508 patients in total for meta-analysis: 238 treated with arthroplasty and 270 treated non-surgically, of which 83 were treated with HA and 155 with RSA. All relevant information was collected, including functional scores, VAS, range of motion, and complications. The study found no significant difference in functional outcomes (mean difference, 2.82; 95% confidence interval, -0.49 to 6.14; P = 0.10; I 2 = 77%) and complications (mean difference, 1.08; 95% confidence interval, 0.51-2.25; P = 0.85; I 2 = 47%) between arthroplasty and non-surgical treatment. Both RCTs and nRCTs showed the same results. However, VAS scores were significantly lower in surgical treatment compared to non-surgical treatment. Subgroup and sensitivity analyses showed that RSA could achieve better functional scores than non-surgical treatment (mean difference, 6.00; 95% confidence interval, 1.97-10.03; P = 0.004; I 2 = 0%), while the results for HA were not significant (P > 0.05). Conclusion: There were no significant differences in complications between arthroplasty and non-surgical treatment for PHFs. RSA could achieve better functional results than non-surgical treatment, while HA could only achieve better forward flexion.

Bone support correlation of X-Ray and CT for a new PE-glenoid.

INTRODUCTION: The radiographic evaluation of novel cementless anatomic polyethylene (PE) glenoid components featuring a titanium-coated back is still unclear. This study explores potential radiolucent lines (RLL) between the radiopaque titanium layer and sclerotic convex reamed bone in an intermodal comparison analysis with computed tomography (CT) scans. MATERIALS AND METHODS: Eight RM pressfit vitamys glenoids (Mathys®) were implanted into cadaveric scapulae. In the CT scans, glenoids were quantified by evaluating ideal complete bony support (NO GAP) and gap between bone and titanium coating (GAP). X-rays were in perfect 0-degree projection and tilted in ± 10° and ± 20° mediolateral (ml) and craniocaudal (cc) directions. Radiographs evaluated were graded as NO RLL, RLL (gap > 1 mm) or DL (double line, gap < 1 mm) in an intermodal comparison of CT and X-ray findings. RESULTS: The inter-rater (Cohen's = 0.643) and intra-rater reliability (Cohen's = 0.714) were good. The overall evaluation showed a significant agreement between (NO) RLL on X-ray and (NO) GAP on CT (p < 0.001). The - 10-degree ml projection showed good agreement between CT and X-ray (Cohen's = 0.628). Adequate agreement was shown at 0 degrees (Cohen's = 0.386), + 10 degrees ml (Cohen's = 0.338), and + 20 degrees cc (Cohen's = 0.327). Compared to the scenario DL = NO RLL, the true a.p. view showed better sensitivity when the DL is classified as RLL. Conversely, the true a.p. view demonstrated both better specificity and significant agreement between the X-ray and CT findings in scenario when DL = No RLL. CONCLUSION: Standard true a. p. projections are reliable in ruling out gaps when no RLL or DL is visible and the detection of RLL shows high intermodal agreement. Varying agreement across tilting angles emphasizes the importance of a comprehensive approach in evaluating bone support and CT is indispensable for a scientifically reliable assessment. LEVEL OF EVIDENCE: Level III Treatment Study.

An in vitro study of glenoid implant peripheral peg interface mechanics during eccentric loading and lift-off.

Glenoid implants used in anatomic total shoulder arthroplasties typically incorporate peripheral pegs as a design feature to support eccentric loads. These peripheral pegs and the implant-cement-bone interface undergo substantial cyclic tensile-compressive loads during normal activity. Therefore, these pegs are of interest in translating the micromechanics of local implant fixation failure to the biomechanics of gross anatomic failure of the glenoid implant after total shoulder arthroplasty. This study used an in vitro peg-cement-bone construct which incorporated bone tissue acquired from osteoarthritic patients undergoing total shoulder arthroplasty. Strain distributions in the peripheral peg-cement-bone interfaces were analyzed under loading conditions emulating glenoid implant edge displacements. It was found that tensile strains in the interfaces were highest near the backside-peg junction and were greater in magnitude than compressive strains. Notably, strains near the peg's fixation channels were relatively low. These results suggest that cracks may initiate around the peg near the backside and travel downward to cause broader fixation failure.

[Application of tuberosity suture combined with autogenous bone grafting in reverse total shoulder arthroplasty for elderly patients with proximal humeral fractures].

Objective: To analyze the effectiveness of tuberosity suture combined with autogenous bone grafting in reverse total shoulder arthroplasty for elderly patients with proximal humerus fracture. Methods: A clinical data of 28 patients with fresh proximal humerus fractures, who met the selection criteria and admitted between June 2014 and April 2022, was retrospectively analyzed. There were 7 males and 21 females. Age ranged from 65 to 81 years, with an average of 73.8 years. The causes of injury were 21 cases of fall, 6 cases of traffic accident, and 1 case of falling from height. The time from injury to operation ranged from 5 to 20 days with an average of 9.2 days. There were 8 cases of Neer three-part fracture and 20 cases of four-part fracture. The reverse total shoulder arthroplasty was performed, and the greater and lesser tuberosities were sutered and reconstructed with autogenous bone grafting. After operation, the Constant score, American Society for Shoulder Surgery (ASES) score, and visual analogue scale (VAS) score were used to evaluate shoulder function and pain; and the active range of motion of the shoulder joint was recorded, including flexion, external rotation, and internal rotation. X-ray films were taken to observe the position of prosthesis. According to the evaluation criteria proposed by Boileau, the healing of greater tuberosity was evaluated, and the effectiveness was compared between the patients with healed and non-healed (displacement and absorption) greater tuberosity. Results: All incisions healed by first intention after operation. All patients were followed up 24-106 months, with an average of 60.9 months. At last follow-up, the VAS score of shoulder joint ranged from 0 to 6 (mean, 1.1). The Constant score ranged from 45 to 100 (mean, 80.1). The ASES score ranged from 57 to 100 (mean, 84.7). The active range of motions of shoulder joint were 60°-160° (mean, 118°) in flexion, 0°-50° (mean, 30°) in external rotation, and corresponding to reaching the S 5-T 8 vertebral body level in internal rotation. During follow-up, no shoulder joint re-dislocation or severe shoulder instability occurred, and no revision surgery was performed. X-ray film reexamination showed that there was no loosening of the prosthesis. According to the evaluation criteria proposed by Boileau, the greater tuberosity fused in 22 cases (78.6%), displaced in 3 cases (10.7%), and absorbed in 3 cases (10.7%). The shoulder joint function and pain related evaluation indicators in the healed group were significantly better than those in the non-healed group ( P<0.05). Conclusion: Tuberosity suture combined with autogenous bone grafting is a relatively simple procedure that provides a reliable fixation for the anatomic recovery of greater and lesser tuberosities and is beneficial for the recovery of shoulder function in elderly patients with proximal humeral fractures.

Finite element analysis part 1 of 2: Influence of short stem implant polyethylene configuration on glenohumeral joint biomechanics.

Purpose: Stress shielding in short-stem arthroplasty can cause critical metaphyseal bone loss. If the size and shape of the humeral shaft are important factors, it is unknown whether the shape of the polyethylene component in reverse shoulder arthroplasty (RSA) affects bone stress around or within the stem. We explored the impact of polyethylene shape on humeral and scapular stress distribution using a finite element model. Methods: We developed a shoulder-specific finite element model. A defined set of muscle forces was applied to simulate movements. An intact rotator cuff state and a superior deficient rotator cuff state were modelled. We used the FX V135 short stem in three conditions: total shoulder arthroplasty (TSA), and RSA with symmetrical and asymmetrical polyethylene (145°/135°). We measured biomechanical markers related to bone stress for different implant sizes. Joint kinematics and the mechanical behaviour of the implant were compared. Results: Rupture of the supraspinatus muscle produced a functionally limited shoulder. The placement of an anatomic TSA with an intact rotator cuff restored function similar to that of a healthy shoulder. RSA in the rotator cuff-deficient shoulder restored function regardless of stem size and polyethylene shape. While stem size had an impact on the stress distribution in the bone and implant, it did not show significant potential for increasing or decreasing overall stress. For the same stem, stress distribution at the humerus is different between TSA and RSA. Polyethylene shape did not alter the transmission of stress to the bone in RSA. Asymmetric polyethylene produced a greater abduction range of motion. Conclusions: In terms of bone stress distribution, smaller stems seemed more appropriate for TSA, while larger stems may be more appropriate for RSA. Polyethylene shape resulted in different ranges of motion but did not influence bone stress. Level of Evidence: Diagnostic Tests or Criteria; Level IV.

Finite element analysis part 2 of 2: Glenohumeral bone stress distribution depends on implant configuration for anatomic and reverse stemless shoulder implants.

Purpose: Our purpose was to quantify stresses in the bone surrounding stemless implants in various configurations. Methods: A detailed finite element model of the glenohumeral joint was used to simulate abduction kinematics before and after arthroplasty and to measure bone stresses around the implants. Two digital patients were simulated: one healthy and one with supraspinatus muscle impairment (deficiency). Two anatomic total shoulder arthroplasty (TSA) configurations were placed in a 135° cutting plane. Two reverse shoulder arthroplasty (RSA) configurations with cutting angles of 135° and 145° were simulated with asymmetrical and symmetrical polyethylene cups, respectively, to obtain humeral neck-shaft angles of 145°. Results: Compared with preoperative models, TSA preserved and RSA restored abduction kinematics. The bone mechanical stresses were located mainly around the central stud of the TSA and were more peripheral to the RSA humeral components. The RSA configuration with the 145° cutting angle and symmetrical cup generated the lowest maximal bone stress and bone volume involvement. Stresses in the scapular cortical bone were highest in the supraspinatus fossa for TSA and the crest of the acromion for RSA. Conclusion: Early stability and glenohumeral bone stress change with implant configuration and should not be extrapolated from anatomic clinical data to reverse configurations. Level of Evidence: Diagnostic tests or criteria; Level IV.

Demographic-, Radiographic-, and Surgery-Related Factors Do Not Affect Functional Internal Rotation Following Reverse Total Shoulder Arthroplasty: A Retrospective Comparative Study.

PURPOSE: This study aimed to identify the demographic-, radiographic-, and surgery-related factors influencing postoperative functional internal rotation (fIR) following reverse total shoulder arthroplasty (RTSA). METHODS: In this retrospective cohort study, patients who underwent RTSA between June 2013 and April 2018 at a single institution were assigned to two groups ("IROgood" or "IRObad"). Patients were classified as having good fIR (≥8 points in the Constant-Murley score (CS) and fIR to the twelfth thoracic vertebra or higher) or poor fIR (≤2 points in the CS and fIR to the twelfth thoracic vertebra or lower) after RTSA with a single implant model. The minimum follow-up period was two years. Standardized shoulder-specific scores (Visual Analogue Scale (VAS), Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons Score (ASES), Constant-Murley score (CS)) were used to assess the pre- and postoperative functional status of patients. Postoperative radiographic evaluation included the distalization shoulder angle (DSA), lateralization shoulder angle (LSA), critical shoulder angle (CSA), acromiohumeral distance (AHD), glenoid inclination (GI), medialization of the center of rotation (COR), lateralization of the humerus, and distalization of the greater tuberosity. Additionally, preoperative evaluation included rotator cuff arthropathy according to Hamada, glenoid version, anterior or posterior humeral head subluxation, and fatty infiltration of the rotator cuff according to Goutallier. Univariate analysis of demographic, surgical, radiographic, and implant-associated parameters was performed to identify factors associated with postoperative fIR. The Shapiro-Wilk test assessed the normal distribution of the data. Intergroup comparisons regarding demographic and surgery-related factors were conducted using the Mann-Whitney-U Test. Radiographic changes were compared using chi-square or Fisher's exact tests. The significance level was set at p < 0.05. RESULTS: Of a total of 42 patients, 17 (age: 73.7 ± 5.0 years, follow-up (FU) 38 months [IQR 29.5-57.5]) were included in the "IRObad" group, and 25 (age: 72 ± 6.1 years, FU 47 months [IQR 30.5-65.5]) were included in the "IROgood" group. All patients were treated with the same type of implant (glenosphere size: 36 mm, 14.3%; 39 mm, 38.1%; 42 mm, 47.6%; neck-shaft angle: 135° in 68.0%; 155° in 32.0%) and had comparable indications. Univariate analysis did not reveal any of the investigated demographic, radiographic, or surgery-related parameters as risk factors for poor postoperative fIR (p > 0.05). CONCLUSION: None of the investigated factors, including implant-associated parameters, influenced postoperative fIR after RTSA in this cohort.

Do modifiable patient factors increase the risk of postoperative complications after total joint arthroplasty?

INTRODUCTION: Numerous studies demonstrate that modifiable lifestyle risk factors can influence patient outcomes including survivability, quality of life, and postoperative complications following orthopaedic surgery. The purpose of this study was to determine the impact of modifiable lifestyle risk factors on postoperative medical and surgical complications following a total joint arthroplasty (TJA) in a large national healthcare system. METHODS: A retrospective chart review of a large national health system database was performed to identify patients who underwent TJA between 2017 and 2021. TJA included total knee arthroplasty, total hip arthroplasty, and total shoulder arthroplasty. Modifiable lifestyle risk factors were defined as tobacco use, narcotic drug abuse, hypertension, and diabetes mellitus. Postoperative medical complications and postoperative surgical complications were collected. Logistic regression and odds ratio point estimate analysis were conducted to assess for associations between postoperative complications and modifiable lifestyle risk factors. RESULTS: Of the 16,940 patients identified, the mean age was 71 years, mean BMI was 29.7 kg/m2, and 62% were women. We found that 3.5% had used narcotics, 8.7% were past or current smokers, 24% had diabetes, and 61% had hypertension; in addition, 5.4% experienced postoperative medical complications and 6.4% experienced postoperative surgical complications. Patients who used narcotics were 90% more likely to have postoperative complications (p < 0.0001) and 105% more likely to experience prosthetic complications (p < 0.0001). Similarly, patients with tobacco use were 65% more likely to have postoperative complications (p < 0.0001) and 27% more likely to experience prosthetic complications. CONCLUSIONS: Our results demonstrate critical rates of increased postoperative medical and surgical complications after TJA for patients with narcotic abuse, tobacco use, or diabetes mellitus. Furthermore, adopting preoperative interventions and optimization programs informed by our findings on specific modifiable risk factors could aid orthopaedic surgeons in optimizing patient health. LEVEL OF EVIDENCE: III; Retrospective study.

Predicting Unplanned Return to Operating Room Following Primary Total Shoulder Arthroplasty: Insights from Fair and Explainable Ensemble Machine Learning.

Reoperation is the most significant complication following any surgical procedure. Developing machine learning methods that predict the need for reoperation will allow for improved shared surgical decision making and patient-specific and preoperative optimisation. Yet, no precise machine learning models have been published to perform well in predicting the need for reoperation within 30 days following primary total shoulder arthroplasty (TSA). This study aimed to build, train, and evaluate a fair (unbiased) and explainable ensemble machine learning method that predicts return to the operating room following primary TSA with an accuracy of 0.852 and AUC of 0.91.

Clinical and radiological results of the SIMPLICITI* stemless shoulder arthroplasty: a twenty five patients retrospective cohort.

PURPOSE: For preserving the humeral bone stock, some surgeons proposed a stemless humeral prosthetic component. This study reports the functional and radiologic results of the stemless anatomic prosthesis Simpliciti*(Tornier, Wright, Stryker), with the hypothesis that it can achieve a good metaphyseal fixation. METHODS: 28 patients underwent 30 shoulder replacements with the Simpliciti* humeral prosthesis followed for an average of three years (2 months to 8 years). The clinical outcome used the Constant-Murley score and the Bankes resistance and force evaluation. The radiologic assessment looked after radiolucent lines, signs of implant migration, osteolysis or loosening. RESULTS: The Constant score improved from 19.03 preoperatively to 54.03 points post operatively. Radiographic analysis showed one early component loosening, and at the longer follow-up, one radiolucent line. All the other implants appeared well fixed. CONCLUSION: This study verified the quality of the metaphyseal fixation of this stemless implant, with achieving a significant functional improvement. LEVEL OF EVIDENCE: Level IV, Case Series, Treatment Study.

Access to Shoulder Arthroplasty in Australia - A balance of regulation, surveillance and monitored efficacy to maximise patient outcome and optimum care.

Prosthetic arthroplasty has emerged as a major contributor to the management of shoulder disorders. This paper outlines the situation in Australia regarding the process by which shoulder replacement devices are made available. While entry of joint replacement devices to the Australian market is relatively unrestricted, they must be first be approved by the Therapeutic Goods Administration (TGA) - based on safety and efficacy - to be legally used. In addition, to obtain a private insurance rebate (Prescribed List) and thus be commercially viable, the Federal Department of Health and Aged Care requires a more stringent benchmark of comparative clinical effectiveness, and value for money. The AOANJRR (Australian Orthopaedic Associate National Joint Replacement Registry)1 records the implantation and possible revision of virtually all (>98%) major joint arthroplasties in Australia and plays an important role informing surgeons about their implant selection, but also in identifying and highlighting devices with a higher than anticipated rate of revision. While the increased cost of health care is placing pressure on health care systems around the world, in Australia access to shoulder arthroplasty remains relatively unrestricted - but carefully controlled and monitored.

Appropriateness of Prior Authorization Requirements for Total Shoulder Arthroplasty: A Systematic Review.

INTRODUCTION: Total shoulder arthroplasty (TSA) has become increasingly utilized for managing glenohumeral osteoarthritis (GHOA), with procedure rates expected to rise. Consequently, there has been a surge in prior authorization (PA) requests for TSA, imposing a substantial administrative burden and highlighting the need for physician advocates to challenge the current PA system. A notable PA requirement is preoperative physical therapy (PT), a treatment modality for GHOA that has not been extensively studied and is not endorsed by the American Academy of Orthopedic Surgery (AAOS) as necessary for the treatment for GHOA. METHODS: We conducted a systematic literature search using PubMed, Embase, and Medline, adhering to PRISMA guidelines. Our search focused on studies with level IV evidence or higher that examined the efficacy preoperative PT for patients with GHOA. RESULTS: We found 210 studies of which three met our inclusion criteria. Our results were mixed, with two of the three studies supporting the use of preoperative PT. Only one study employed a randomized controlled trial (RCT) design, underscoring the need for more high-quality studies in this area. DISCUSSION/CONCLUSION: Our findings suggest that there is limited evidence for the benefit of preoperative PT in GHOA. This contradicts the current PA requirements which require patients to undergo preoperative PT to receive coverage for treatment. This review highlights the need for physician engagement in advocacy efforts to challenge these current requirements and improve patient care.

Does Use of GLP-1 Agonists Increase Postoperative Complications in Patients Undergoing Shoulder Arthroplasty?

BACKGROUND: Amidst the rising prevalence of type 2 diabetes mellitus (T2DM) and obesity among individuals undergoing total shoulder arthroplasty (TSA), the impact of glucagon-like-peptide-1 (GLP-1) therapy on surgical outcomes merits thorough investigation. Though it is known that GLP-1 therapy poses an interesting challenge for anesthesia during the perioperative period, little is known regarding the effects of these medications on surgical outcomes. This study aimed to evaluate the influence of GLP-1 on postoperative outcomes and length of stay (LOS) in T2DM patients undergoing TSA. METHODS: A retrospective cohort analysis was performed using a national database to identify primary TSA patients aged 18 and above with T2DM prescribed GLP-1 therapy at the time of surgery. Exclusion criteria included revision surgery, TSA for fracture, type 1 diabetes, steroid-induced diabetes, and contraindications for GLP-1 therapy. A control group of T2DM TSA patients not on GLP-1 therapy was used, and a 1:4 propensity-score match was performed. Incidence rates and odds ratios (OR) via multivariable logistic regression were calculated. The primary outcomes were 90-day major medical complications and LOS. Secondary outcomes included 2-year joint-related complications. RESULTS: In the 90-day follow-up cohort, 64,567 patients met inclusion criteria, with 8,481 (13.1%) on GLP-1 therapy. No significant increase in 90-day major complications, including DVT, cardiac arrest, myocardial infarction, cerebrovascular accident, pneumonia, pulmonary embolism, urinary tract infection, surgical site infection, hypoglycemic event, sepsis, or readmission, was found between GLP-1 and non-GLP-1 cohorts after multivariable logistic regression. In the 2-year follow-up cohort, 47,814 patients were included, with 5,969 (12.5%) on GLP-1 therapy. Similarly, 2-year joint-related complications, including all-cause revision, prosthetic joint infection, periprosthetic fracture, and aseptic revision, showed no significant differences between the GLP-1 and non-GLP-1 cohorts. No significant difference was observed in LOS in the 90-day cohort. CONCLUSION: This study provides a comprehensive analysis of GLP-1 therapy's impact on TSA outcomes, revealing no significant change in postoperative complications or LOS. The lack of increased postoperative risk underscores the potential of GLP-1 therapy in managing T2DM without adverse effects on TSA recovery. These insights contribute to understanding postoperative management in orthopedic surgery, indicating that we did not note any increased risk with GLP-1 use perioperatively in TSA patients, unlike in other populations like the TKA patients. Future research should focus on prospective analyses to further elucidate the role of GLP-1 therapy in surgical outcomes, aiming to enhance patient care and optimize postoperative strategies for T2DM patients undergoing TSA.

Reverse Allograft Prosthetic-Composite Versus Endoprosthesis Reconstruction for Massive Proximal Humerus Bone Loss: A Systematic Review and Meta-analysis of Outcomes and Complications.

Background: This systematic review and meta-analysis sought to compare the clinical outcomes after proximal humerus reconstruction with a reverse allograft-prosthetic composite (APC) versus reverse endoprosthesis. Methods: Per PRISMA guidelines, we queried PubMed/MEDLINE, Embase, Web of Science, and Cochrane databases to identify articles reporting clinical outcomes of reverse APC or reverse endoprosthesis reconstruction of the proximal humerus for massive bone loss secondary to tumor, fracture, or failed arthroplasty. We compared postoperative range of motion, outcome scores, and the incidence of complications and revision surgery. Results: Of 259 unique articles, 18 articles were included (267 APC, 260 endoprosthesis). There were no significant differences between the APC and endoprosthesis cohort for postoperative forward elevation (P = .231), external rotation (P = .634), ASES score (P = .420), Constant score (P = .414), MSTS (P = .815), SST (P = .367), or VAS (P = .714). Rate of complications was 15% (31/213) in the APC cohort and 19% (27/144) in the endoprosthesis cohort. The rate of revision surgery was 12% after APC cohort and 7% after endoprosthesis. APC-specific complications included a 10% APC nonunion/malunion/resorption rate and 6% APC fracture/fragmentation rate. Discussion: Reverse APC and endoprosthesis are reasonable options for proximal humerus reconstruction. APC carries additional risks for complications, warranting evaluation of patients' healing capacity and surgeon experience. Level of Evidence: Level IV; Systematic Review. Supplementary Information: The online version contains supplementary material available at 10.1007/s43465-024-01248-7.