Oxidized Zirconium Versus Cobalt Chromium for Primary TKA: No Difference in Midterm Revision Rates From the American Joint Replacement Registry.

BACKGROUND: Cobalt chromium (CoCr) is the most commonly used material in TKA; however, the use of oxidized zirconium (OxZr) implants has increased. The advantages to this material demonstrated in basic science studies have not been borne out in clinical studies to date. QUESTION/PURPOSE: In the setting of the American Joint Replacement Registry (AJRR), how do revision rates differ between CoCr and OxZr after primary TKA? METHODS: The AJRR was accessed for all primary TKAs performed between 2012 and 2020 for osteoarthritis, resulting in 441,605 procedures (68,506 with OxZr and 373,099 with CoCr). The AJRR is the largest joint replacement registry worldwide and collects procedure-specific details, making it ideal for large-scale comparisons of implant materials in the United States. Competing risk survival analyses were used to evaluate the all-cause revision rates of primary TKAs, comparing CoCr and OxZr implants. Data from the Centers for Medicare and Medicaid Services claims from 2012 to 2017 were also cross-referenced to capture additional revisions from other institutions. Revision rates were tabulated and subclassified by indication. Multivariate Cox regression was used to account for confounding variables such as age, gender, region, and hospital size. RESULTS: After controlling for confounding variables, there were no differences between the OxZr and CoCr groups in terms of the rate of all-cause revision at a mean follow-up of 46 ± 23 months and 44 ± 24 months for CoCr and OxZr implants, respectively (hazard ratio 1.055 [95% confidence interval 0.979 to 1.137]; p = 0.16) The univariate analysis demonstrated increased rates of revisions for pain and instability in the OxZr group (p = 0.003 and p < 0.001, respectively). CONCLUSION: These findings suggest there is no difference in all-cause revision between OxZr and CoCr implants in the short-term to mid-term. However, further long-term in vivo studies are needed to monitor the safety and all-cause revision rate of OxZr implants compared with those of CoCr implants. OxZr implants may be favorable in patients who have sensitivity to metal. Despite similar short-term to mid-term all-cause revision rates to CoCr implants, because of the limitations of this study, definitive recommendations for or against the use of OxZr cannot be made. LEVEL OF EVIDENCE: Level III, therapeutic study.

Prediction of Admission Costs Following Anterior Cervical Discectomy and Fusion Utilizing Machine Learning.

STUDY DESIGN: Retrospective case series. OBJECTIVE: Predict cost following anterior cervical discectomy and fusion (ACDF) within the 90-day global period using machine learning models. BACKGROUND: The incidence of ACDF has been increasing with a disproportionate decrease in reimbursement. As bundled payment models become common, it is imperative to identify factors that impact the cost of care. MATERIALS AND METHODS: The Nationwide Readmissions Database (NRD) was accessed in 2018 for all primary ACDFs by the International Classification of Diseases 10th Revision (ICD-10) procedure codes. Costs were calculated by utilizing the total hospital charge and each hospital's cost-to-charge ratio. Hospital characteristics, such as volume of procedures performed and wage index, were also queried. Readmissions within 90 days were identified, and cost of readmissions was added to the total admission cost to represent the 90-day healthcare cost. Machine learning algorithms were used to predict patients with 90-day admission costs >1 SD from the mean. RESULTS: There were 42,485 procedures included in this investigation with an average age of 57.7±12.3 years with 50.6% males. The average cost of the operative admission was $24,874±25,610, the average cost of readmission was $25,371±11,476, and the average total cost was $26,977±28,947 including readmissions costs. There were 10,624 patients who were categorized as high cost. Wage index, hospital volume, age, and diagnosis-related group severity were most correlated with the total cost of care. Gradient boosting trees algorithm was most predictive of the total cost of care (area under the curve=0.86). CONCLUSIONS: Bundled payment models utilize wage index and diagnosis-related groups to determine reimbursement of ACDF. However, machine learning algorithms identified additional variables, such as hospital volume, readmission, and patient age, that are also important for determining the cost of care. Machine learning can improve cost-effectiveness and reduce the financial burden placed upon physicians and hospitals by implementing patient-specific reimbursement.

Prediction of total healthcare cost following total shoulder arthroplasty utilizing machine learning.

BACKGROUND: Given the increase in demand in treatment of glenohumeral arthritis with anatomic total (aTSA) and reverse shoulder arthroplasty (RTSA), it is imperative to improve quality of patient care while controlling costs as private and federal insurers continue its gradual transition toward bundled payment models. Big data analytics with machine learning shows promise in predicting health care costs. This is significant as cost prediction may help control cost by enabling health care systems to appropriately allocate resources that help mitigate the cause of increased cost. METHODS: The Nationwide Readmissions Database (NRD) was accessed in 2018. The database was queried for all primary aTSA and RTSA by International Classification of Diseases, Tenth Revision (ICD-10) procedure codes: 0RRJ0JZ and 0RRK0JZ for aTSA and 0RRK00Z and 0RRJ00Z for RTSA. Procedures were categorized by diagnoses: osteoarthritis (OA), rheumatoid arthritis (RA), avascular necrosis (AVN), fracture, and rotator cuff arthropathy (RCA). Costs were calculated by utilizing the total hospital charge and each hospital's cost-to-charge ratio. Hospital characteristics were included, such as volume of procedures performed by the respective hospital for the calendar year and wage index, which represents the relative average hospital wage for the respective geographic area. Unplanned readmissions within 90 days were calculated using unique patient identifiers, and cost of readmissions was added to the total admission cost to represent the short-term perioperative health care cost. Machine learning algorithms were used to predict patients with immediate postoperative admission costs greater than 1 standard deviation from the mean, and readmissions. RESULTS: A total of 49,354 patients were isolated for analysis, with an average patient age of 69.9 ± 9.6 years. The average perioperative cost of care was $18,843 ± $10,165. In total, there were 4279 all-cause readmissions, resulting in an average cost of $13,871.00 ± $14,301.06 per readmission. Wage index, hospital volume, patient age, readmissions, and diagnosis-related group severity were the factors most correlated with the total cost of care. The logistic regression and random forest algorithms were equivalent in predicting the total cost of care (area under the receiver operating characteristic curve = 0.83). CONCLUSION: After shoulder arthroplasty, there is significant variability in cumulative hospital costs, and this is largely affected by readmissions. Hospital characteristics, such as geographic area and volume, are key determinants of overall health care cost. When accounting for this, machine learning algorithms may predict cases with high likelihood of increased resource utilization and/or readmission.

Predicting Patient Satisfaction With Maximal Outcome Improvement After Biceps Tenodesis.

The goal of this study was to determine the threshold for achieving maximal outcome improvement (MOI) on the American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), and Constant-Murley (CM) questionnaires that predict satisfaction after isolated biceps tenodesis without concomitant rotator cuff repair. A retrospective analysis of prospectively collected data was performed for patients undergoing isolated biceps tenodesis from 2014 to 2017 at a single institution with minimum 6-month follow-up. Receiver operating characteristic curve analysis was used to determine thresholds for MOI for the ASES, SANE, and CM questionnaires. Stepwise multivariate logistical regression analysis was performed to identify predictors for achieving the threshold for MOI. A total of 123 patients were included in the final analysis. Receiver operating characteristic analysis determined that achieving 43.1%, 62.1%, and 61.4% MOI was the threshold for satisfaction for the ASES, SANE, and CM questionnaires, respectively. Regression analysis showed that concomitant superior labrum anterior-posterior (SLAP) repair was predictive of achieving MOI on the ASES and SANE questionnaires, whereas partial rotator cuff tear was predictive of achieving MOI on the CM questionnaire (P<.05 for both). Further, workers' compensation status, diabetes, history of ipsilateral shoulder surgery, and hypertension were negative predictors of achieving MOI on the SANE and CM questionnaires (P<.05 for all). Achieving MOI of 43.1%, 62.1%, and 61.4% is the threshold for satisfaction after biceps tenodesis for the ASES, SANE, and CM questionnaires, respectively. Concomitant SLAP repair was positively predictive of achieving MOI, whereas workers' compensation status, diabetes, history of ipsilateral shoulder surgery, and hypertension were negative predictors. [Orthopedics. 2021;44(3):e359-e366.].

Correlation of Voice Hoarseness and Vocal Cord Palsy: A Prospective Assessment of Recurrent Laryngeal Nerve Injury Following Anterior Cervical Discectomy and Fusion.

BACKGROUND: Injury to the recurrent laryngeal nerve (RLN) has been implicated as a common complication following anterior cervical discectomy and fusion (ACDF) surgery. The purpose of this study is to determine the true incidence of voice hoarseness and RLN palsy following ACDF surgery, to determine the reliability of symptoms in the diagnosis of RLN injury, and to evaluate factors related to the development of these symptoms. METHODS: All patients undergoing elective (primary or secondary) ACDF surgery at a single institution consented to and enrolled in the present study. All approaches were through the left side. Enrolled patients received both preoperative and postoperative (within 1 month following surgery) laryngoscopy by a fellowship-trained ENT physician for evaluation of RLN function. Patients also responded as to whether they were experiencing postoperative symptoms of dysphagia, aspiration, and voice changes. RESULTS: In total, 108 patients were included in this study. Mean age of the population was 59.2 ± 10.7 years and mean body mass index was 31.2 ± 7.1 kg/m2. Three patients had previously undergone a thyroidectomy, whereas 20 patients had undergone a previous ACDF. Average intubation time for ACDF surgery was 121.6 ± 38.5 minutes. After surgery and excluding patients who were experiencing preoperative symptoms, 19 patients (20.4%) complained of dysphagia, 2 patients (1.9%) complained of aspiration symptoms, and 5 patients (4.6%) complained of voice hoarseness. There was no incidence of vocal cord palsy from postoperative laryngoscopy. From multivariate analysis, endotracheal cuff pressure after retractor placement was correlated to postoperative voice hoarseness, dysphagia, and aspiration symptoms. CONCLUSIONS: From the results of this prospective study, the RLN remained functional even a month after surgery despite several cases of postoperative dysphagia, aspiration, and voice changes. Endotracheal cuff pressure, number of vertebral levels, body mass index, and intubation time were important variables related to postoperative symptoms. CLINICAL RELEVANCE: Voice hoarseness does not necessarily indicate recurrent laryngeal nerve injury after ACDF but may be caused by compressive forces on laryngeal tissue during retraction or intubation. Laryngoscopy should be performed in cases with high clinical suspicion. LEVEL OF EVIDENCE: 2.

Assessment and Trends of the Methodological Quality of the Top 50 Most Cited Articles on Patellar Instability.

BACKGROUND: Studies with a low level of evidence (LOE) have dominated the top cited research in many areas of orthopaedics. The wide range of treatment options for patellar instability necessitates an investigation to determine the types of studies that drive clinical practice. PURPOSE: To determine (1) the top 50 most cited articles on patellar instability and (2) the correlation between the number of citations and LOE or methodological quality. STUDY DESIGN: Cross-sectional study. METHODS: The Scopus and Web of Science databases were assessed to determine the top 50 most cited articles on patellar instability between 1985 and 2019. Bibliographic information, number of citations, and LOE were collected. Methodological quality was calculated using the Modified Coleman Methodology Score (MCMS) and the Methodological Index for Non-Randomized Studies (MINORS). Mean citations and mean citation density (citations per year) were correlated with LOE, MCMS, and MINORS scores. RESULTS: Most studies were cadaveric (n = 10; 20.0%), published in the American Journal of Sports Medicine (n = 13; 26.0%), published between 2000 and 2009 (n = 41; 82.0%), and conducted in the United States (n = 17; 34.0%). The mean number of citations and the citation density were 158.61 ± 59.53 (range, 95.5-400.5) and 12.74 ± 5.12, respectively. The mean MCMS and MINORS scores were 59.62 ± 12.58 and 16.24 ± 3.72, respectively. No correlation was seen between mean number of citations or citation density versus LOE. A significant difference was found in the mean LOE of articles published between 1990 and 1999 (5.0 ± 0) versus those published between 2000 and 2009 (3.12 ± 1.38; P = .03) and between 2010 and 2019 (3.00 ± 1.10; P = .01). CONCLUSION: There was a shift in research from anatomy toward outcomes in patellar instability; however, these articles demonstrated low LOE and methodological quality. Higher quality studies are necessary to establish informed standards of management of patellar instability.

Cost and Complications of Single-Level Lumbar Decompression in Those Over and Under 75: A Matched Comparison.

STUDY DESIGN: Retrospective database analysis. OBJECTIVE: This study aimed to compare costs and complication rates following single-level lumbar decompression in patients under age 75 versus patients aged 75 and older. SUMMARY OF BACKGROUND DATA: Lumbar decompression is a common surgical treatment for lumbar pathology; however, its effectiveness can be debated in elderly patients because complication rates and costs by age group are not well-defined. METHODS: The Medicare database was queried through the PearlDiver server for patients who underwent single-level lumbar decompression without fusion as an index procedure. The 90-day complication and reoperation rates were compared between age groups after matching for sex and comorbidity burden. Same day and 90-day costs are compared. RESULTS: The matched cohort included 89,388 total patients (n = 44,694 for each study arm). Compared to the under 75 age group, the 75 and older age group had greater rates of deep venous thrombosis (odds ratio [OR] 1.443, P = 0.042) and dural tear (OR 1.560, P = 0.043), and a lower rate of seroma complicating the procedure (OR 0.419, P = 0.009). There was no difference in overall 90-day reoperation rate in patients under age 75 versus patients aged 75 and older (9.66% vs. 9.28%, P = 0.051), although the 75 and older age group had a greater rate of laminectomy without discectomy (CPT-63047; OR 1.175, P < 0.001), while having a lower rate of laminotomy with discectomy (CPT-63042 and CPT-63030; OR 0.727 and 0.867, respectively, P = 0.013 and <0.001, respectively). The 75 and older age group had greater same day ($3329.24 vs. $3138.05, P < 0.001) and 90-day ($5014.82 vs. $4749.44, P < 0.001) mean reimbursement. CONCLUSION: Elderly patients experience greater rates of select perioperative complications, with mildly increased costs. There is no significant difference in overall 90-day reoperation rates. LEVEL OF EVIDENCE: 3.

Return to work following distal triceps repair.

PURPOSE: The purpose of this study was to evaluate the rate and duration of return to work in patients undergoing distal triceps repair (DTR). METHODS: Consecutive patients undergoing DTR from 2009 to 2017 at our institution were retrospectively reviewed at a minimum of 1 year postoperatively. Patients completed a standardized and validated work questionnaire; a visual analog scale for pain; the Mayo Elbow Performance Score; the short version of the Disabilities of the Arm, Shoulder and Hand questionnaire; and a satisfaction survey. RESULTS: Of 113 eligible patients who underwent DTR, 81 (71.7%) were contacted. Of these patients, 74 (91.4%) were employed within 3 years prior to surgery (mean age, 46.0 ± 10.7 years; mean follow-up, 5.9 ± 3.9 years). Sixty-nine patients (93.2%) returned to work by 2.2 ± 3.2 months postoperatively. Sixty-six patients (89.2%) were able to return to the same level of occupational intensity. Patients who held sedentary-, light-, medium-, and high-intensity occupations were able to return to work at a rate of 100.0%, 100.0%, 80.0%, and 76.9%, respectively, by 0.3 ± 0.5 months, 1.8 ± 1.5 months, 2.5 ± 3.6 months, and 4.8 ± 3.9 months, respectively, postoperatively. Of the workers' compensation patients, 15 (75%) returned to work by 6.5 ± 4.3 months postoperatively, whereas 100% of non-workers' compensation patients returned to work by 1.1 ± 1.6 months (P < .001). Seventy-one patients (95.9%) were at least somewhat satisfied, with 50 patients (67.6%) reporting excellent satisfaction. Seventy-two patients (97.3%) would undergo the operation again if presented the opportunity. A single patient (1.4%) required revision DTR. CONCLUSIONS: Approximately 93% of patients who underwent DTR returned to work by 2.2 ± 3.2 months postoperatively. Patients with higher-intensity occupations had an equivalent rate of return to work but took longer to return to their preoperative level of occupational intensity. Information regarding return to work is imperative in preoperative patient consultation to manage expectations.

Assessment and Trends in the Methodological Quality of the Top 50 Most Cited Articles in Shoulder Instability.

BACKGROUND: Citation counts have often been used as a surrogate for the scholarly impact of a particular study, but they do not necessarily correlate with higher-quality investigations. In recent decades, much of the literature regarding shoulder instability is focused on surgical techniques to correct bone loss and prevent recurrence. PURPOSE: To determine (1) the top 50 most cited articles in shoulder instability and (2) if there is a correlation between the number of citations and level of evidence or methodological quality. STUDY DESIGN: Cross-sectional study. METHODS: A literature search was performed on both the Scopus and the Web of Science databases to determine the top 50 most cited articles in shoulder instability between 1985 and 2019. The search terms used included "shoulder instability," "humeral defect," and "glenoid bone loss." Methodological scores were calculated using the Modified Coleman Methodology Score (MCMS), Jadad scale, and Methodological Index for Non-Randomized Studies (MINORS) score. RESULTS: The mean number of citations and mean citation density were 222.7 ± 123.5 (range, 124-881.5) and 16.0 ± 7.9 (range, 6.9-49.0), respectively. The most common type of study represented was the retrospective case series (evidence level, 4; n = 16; 32%) The overall mean MCMS, Jadad score, and MINORS score were 61.1 ± 10.1, 1.4 ± 0.9, and 16.0 ± 3.0, respectively. There were also no correlations found between mean citations or citation density versus each of the methodological quality scores. CONCLUSION: The list of top 50 most cited articles in shoulder instability comprised studies with low-level evidence and low methodological quality. Higher-quality study methodology does not appear to be a significant factor in whether studies are frequently cited in the literature.

Single Assessment Numeric Evaluation (SANE) is a reliable metric to measure clinically significant improvements following shoulder arthroplasty.

BACKGROUND: Single Assessment Numeric Evaluation (SANE) offers a simple method of evaluating patients' sense of functional improvement after shoulder arthroplasty. METHODS: Patients receiving total shoulder arthroplasties were retrospectively queried between 2014 and 2017. Patients completed questionnaires involving SANE, American Shoulder and Elbow Surgeons (ASES) score, and Constant scores at the 1-year interval. Minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) were calculated using the anchor-based methodology. RESULTS: A total of 207 patients with an average age of 66.7 ± 10.3 years and a body mass index of 31.5 ± 7.3 were available for analysis. The SANE score was the only score to have acceptable area under curve (AUC) (70.5%) for achieving MCID with a cutoff of 28.8. In terms of SCB, ASES (88%) and SANE (70.5%) had acceptable AUC with cutoffs of 20.7 and 50.2, respectively. All 3 scores had excellent AUC (>80%) for PASS with cutoffs of 81.9, 75.5, and 24.5 for ASES, SANE, and Constant scores, respectively. Normalized SANE scores were weakly correlated with ASES and Subjective Constant after normalizing for scale (R2 < 0.4). Achieving MCID by SANE was correlated with achieving MCID by Constant (P < .001). Achieving SCB and PASS by SANE was correlated with achieving SCB and PASS by ASES and Constant (ASES: P = .007, P < .001; Constant: P < .001, P < .001). CONCLUSION: The present study establishes clinically significant outcomes for SANE. Achievement of clinically significant outcomes in SANE was correlated with achieving meaningful outcomes with legacy measures of ASES and Constant scores. SANE may be used as a simple and efficient measure of patient outcome after total shoulder arthroplasty.

Establishing minimal clinically important difference, substantial clinical benefit, and patient acceptable symptomatic state after biceps tenodesis.

BACKGROUND: The purposes of this study were to establish thresholds for improvement in patient-reported outcome scores that signify the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) after biceps tenodesis (BT) and to assess patient variables that are associated with these clinically important outcomes. METHODS: A prospectively maintained institutional shoulder registry was queried for patients undergoing isolated BT between 2014 and 2017. Anchor-based and distribution-based approaches were used to calculate the MCID whereas an anchor-based method was used to calculate the SCB and PASS for the Constant-Murley score, Single Assessment Numerical Evaluation (SANE) score, and American Shoulder and Elbow Surgeons score. RESULTS: A total of 123 patients who underwent isolated BT were included for analysis. The MCID, SCB, and PASS calculated for the American Shoulder and Elbow Surgeons score were 11.0, 16.8, and 59.6, respectively. For the Constant-Murley score, the calculated MCID and PASS were 3.8 and 19.5, respectively. The MCID, SCB, and PASS calculated for the SANE score were 3.5, 5.8, and 65.5, respectively. The following patient variables were significantly associated with decreased odds of achieving the MCID: workers' compensation status, male sex, and higher preoperative SANE score. Patients with a history of ipsilateral shoulder surgery had significantly reduced odds of achieving SCB. The only factor significantly associated with failing to reach the PASS was workers' compensation status. CONCLUSION: This study established values for the MCID, SCB, and PASS after BT without concomitant rotator cuff repair. Workers' compensation status, previous shoulder surgery, male sex, and higher preoperative patient-reported outcome measure scores are associated with lower odds of achieving clinically significant improvement after BT.

Inferior outcomes and higher complication rates after shoulder arthroplasty in workers' compensation patients.

BACKGROUND: Outcomes of shoulder surgery in workers' compensation (WC) patients have generally been inferior to those in non-WC patients. The purpose of this study was to compare the complication rates and clinical outcomes after shoulder arthroplasty in WC patients and control non-WC patients. METHODS: An institutional shoulder arthroplasty database was queried for patients with minimum 2-year follow-up who underwent total shoulder arthroplasty, reverse total shoulder arthroplasty, or hemiarthroplasty. WC patients were age and sex matched with non-WC patients and retrospectively evaluated for complication rates, patient-reported outcome (PRO) scores, and range of motion. RESULTS: We matched 45 WC and 45 non-WC patients by age and sex, with the WC group having a higher rate of prior surgery (82% vs 38%, P < .001). Both groups experienced significant improvements in all PROs, forward elevation, and external rotation (P < .05 for all). The WC group had inferior 2-year outcomes for all PROs and forward elevation (P ≤ .001 for all), as well as a higher reoperation rate (16% vs 2%, P = .030) and higher rate of persistent pain at final follow-up (33% vs 11%, P = .021). On multivariate regression controlling for other variables including number of prior surgical procedures, WC status remained associated with lower improvements in American Shoulder and Elbow Surgeons (P < .001), functional (P < .001), and Simple Shoulder Test (P < .001) scores, as well as a higher reoperation rate (P = .015) and higher rate of persistent pain (P = .027). CONCLUSION: Although both WC and non-WC patients experienced significant clinical improvements after shoulder arthroplasty, WC patients had a higher reoperation rate, inferior PROs, and a higher rate of persistent pain.