Isolated Osteochondral Autograft Versus Allograft Transplantation for the Treatment of Symptomatic Cartilage Lesions of the Knee: A Systematic Review and Meta-analysis

BACKGROUND

Focal cartilage lesions of the knee remain a difficult entity to treat. Current treatment options include arthroscopic debridement, microfracture, autograft or allograft osteochondral transplantation, and cell-based therapies such as autologous chondrocyte transplantation. Osteochondral transplantation techniques restore the normal topography of the condyles and provide mature hyaline cartilage in a single-stage procedure. However, clinical outcomes comparing autograft versus allograft techniques are scarce.

PURPOSE

To perform a comprehensive systematic review and meta-analysis of high-quality studies to evaluate the results of osteochondral autograft and allograft transplantation for the treatment of symptomatic cartilage defects of the knee.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 2.

METHODS

A comprehensive search of the literature was conducted using various databases. Inclusion criteria were level 1 or 2 original studies, studies with patients reporting knee cartilage injuries and chondral defects, mean follow-up ≥2 years, and studies focusing on osteochondral transplant techniques. Exclusion criteria were studies with nonknee chondral defects, studies reporting clinical outcomes of osteochondral autograft or allograft combined with other procedures, animal studies, cadaveric studies, non-English language studies, case reports, and reviews or editorials. Primary outcomes included patient-reported outcomes and failure rates associated with both techniques, and factors such as lesion size, age, sex, and the number of plugs transplanted were assessed. Metaregression using a mixed-effects model was utilized for meta-analyses.

RESULTS

The search resulted in 20 included studies with 364 cases of osteochondral autograft and 272 cases of osteochondral allograft. Mean postoperative survival was 88.2% in the osteochondral autograft cohort as compared with 87.2% in the osteochondral allograft cohort at 5.4 and 5.2 years, respectively (P = .6605). Patient-reported outcomes improved by an average of 65.1% and 81.1% after osteochondral autograft and allograft, respectively (P = .0001). However, meta-analysis revealed no significant difference in patient-reported outcome percentage change between osteochondral autograft and allograft (P = .97) and a coefficient of 0.033 (95% CI, -1.91 to 1.98). Meta-analysis of the relative risk of graft failure after osteochondral autograft versus allograft showed no significant differences (P = .66) and a coefficient of 0.114 (95% CI, -0.46 to 0.69). Furthermore, the regression did not find other predictors (mean age, percentage of female patients, lesion size, number of plugs/grafts used, and treatment location) that may have significantly affected patient-reported outcome percentage change or postoperative failure between osteochondral autograft versus allograft.

CONCLUSION

Osteochondral autograft and allograft result in favorable patient-reported outcomes and graft survival rates at medium-term follow-up. While predictors for outcomes such as mean age, percentage of female patients, lesion size, number of plugs/grafts used, and treatment location did not affect the comparison of the 2 cohorts, proper patient selection for either procedure remains paramount to the success and potentially long-term viability of the graft.

Machine Learning Can Accurately Predict Overnight Stay, Readmission, and 30-Day Complications Following Anterior Cruciate Ligament Reconstruction

PURPOSE

This study aimed to develop machine learning (ML) models to predict hospital admission (overnight stay) as well as short-term complications and readmission rates following anterior cruciate ligament reconstruction (ACLR). Furthermore, we sought to compare the ML models with logistic regression models in predicting ACLR outcomes.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was queried for patients who underwent elective ACLR from 2012 to 2018. Artificial neural network ML and logistic regression models were developed to predict overnight stay, 30-day postoperative complications, and ACL-related readmission, and model performance was compared using the area under the receiver operating characteristic curve. Regression analyses were used to identify variables that were significantly associated with the predicted outcomes.

RESULTS

A total of 21,636 elective ACLR cases met inclusion criteria. Variables associated with hospital admission included White race, obesity, hypertension, and American Society of Anesthesiologists classification 3 and greater, anesthesia other than general, prolonged operative time, and inpatient setting. The incidence of hospital admission (overnight stay) was 10.2%, 30-day complications was 1.3%, and 30-day readmission for ACLR-related causes was 0.9%. Compared with logistic regression models, artificial neural network models reported superior area under the receiver operating characteristic curve values in predicting overnight stay (0.835 vs 0.589), 30-day complications (0.742 vs 0.590), reoperation (0.842 vs 0.601), ACLR-related readmission (0.872 vs 0.606), deep-vein thrombosis (0.804 vs 0.608), and surgical-site infection (0.818 vs 0.596).

CONCLUSIONS

The ML models developed in this study demonstrate an application of ML in which data from a national surgical patient registry was used to predict hospital admission and 30-day postoperative complications after elective ACLR. ML models developed performed well, outperforming regression models in predicting hospital admission and short-term complications following elective ACLR. ML models performed best when predicting ACLR-related readmissions and reoperations, followed by overnight stay.

LEVEL OF EVIDENCE

IV, retrospective comparative prognostic trial.

Mortality Rate Increase in Elderly Patients With Hip Fractures Presenting During the COVID-19 Pandemic to a Hospital in the United States Epicenter: Minimum 30-day Follow Up Comparative Study

The purpose of this study was to compare mortality and complication rates among geriatric patients who sustained a hip fracture before the coronavirus disease (COVID-19) pandemic began to those who presented during the peak of the pandemic. Patients greater than or equal to 50 years of age who presented with a diagnosis of hip fracture from March 16, 2020 to May 1, 2020 were compared with a historical control group who presented between December 1, 2019 and January 16, 2020. Minimum follow up was 30 days. The primary outcome was a 30-day mortality rate. Thirty-day mortality was significantly different between groups, with no deaths of 24 patients in the pre-COVID-19 cohort versus six deaths of 23 patients (26.1%) in the COVID-19 cohort (chi-squared test, p-value = 0.02). The study concluded that the COVID-19 pandemic increased mortality risk for geriatric hip fracture patients. (Journal of Surgical Orthopaedic Advances 32(4):232-237, 2023).

Artificial Learning and Machine Learning Applications in Spine Surgery: A Systematic Review

OBJECTIVES

This current systematic review sought to identify and evaluate all current research-based spine surgery applications of AI/ML in optimizing preoperative patient selection, as well as predicting and managing postoperative outcomes and complications.

METHODS

A comprehensive search of publications was conducted through the EMBASE, Medline, and PubMed databases using relevant keywords to maximize the sensitivity of the search. No limits were placed on level of evidence or timing of the study. Findings were reported according to the PRISMA guidelines.

RESULTS

After application of inclusion and exclusion criteria, 41 studies were included in this review. Bayesian networks had the highest average AUC (.80), and neural networks had the best accuracy (83.0%), sensitivity (81.5%), and specificity (71.8%). Preoperative planning/cost prediction models (.89,82.2%) and discharge/length of stay models (.80,78.0%) each reported significantly higher average AUC and accuracy compared to readmissions/reoperation prediction models (.67,70.2%) (P < .001, P = .005, respectively). Model performance also significantly varied across postoperative management applications for average AUC and accuracy values (P < .001, P < .027, respectively).

CONCLUSIONS

Generally, authors of the reviewed studies concluded that AI/ML offers a potentially beneficial tool for providers to optimize patient care and improve cost-efficiency. More specifically, AI/ML models performed best, on average, when optimizing preoperative patient selection and planning and predicting costs, hospital discharge, and length of stay. However, models were not as accurate in predicting postoperative complications, adverse events, and readmissions and reoperations. An understanding of AI/ML-based applications is becoming increasingly important, particularly in spine surgery, as the volume of reported literature, technology accessibility, and clinical applications continue to rapidly expand.

Incidental Pulmonary Nodules Found on Shoulder Arthroplasty Preoperative CT Scans

With current emphasis on preoperative templating of anatomical and reverse shoulder arthroplasty (aTSA and rTSA, respectively), patients often receive thin slice (<1.0 mm) computerized tomography (CT) scans of the operative shoulder, which includes about two-thirds of the ipsilateral lung. The purpose of this study is to evaluate the prevalence and management of incidentally detected pulmonary nodules on preoperative CT scans for shoulder arthroplasty. In this single-center retrospective study, we queried records of aTSA and rTSA patients from 2015 to 2020 who received preoperative CT imaging of the shoulder. Compared to patients with negative CT findings, there were significantly more females (63.8% vs. 46.4%; P = .011), COPD (13.0% vs. 4.7%; P = .015), and asthma (18.8% vs. 6.9%; P = .003) among the patients with incidental nodules on CT. Binary logistic regression confirmed that female sex (odds ratio = 2.00; 95% CI = 1.04 to 3.88; P = .037), COPD history (OR = 3.02; 95% CI = 1.05 to 8.65; P = .040), and asthma history (OR = 3.17; 95% CI = 1.30 to 7.77; P = .011) were significantly associated with an incidental nodule finding. Incidental pulmonary nodules found on shoulder arthroplasty preoperative CT scans are often low risk in size with low risk of malignancy, and do not require further workup. This study may provide guidance to orthopedic surgeons on how to manage patients with incidental pulmonary nodules to increase chances of early cancer detection, avoid unnecessary referrals, reduce potentially harmful radiation exposure of serial CT scans, and improve cost efficiency.

Machine Learning Model Developed to Aid in Patient Selection for Outpatient Total Joint Arthroplasty

Background

Patient selection for outpatient total joint arthroplasty (TJA) is important for optimizing patient outcomes. This study develops machine learning models that may aid in patient selection for outpatient TJA based on medical comorbidities and demographic factors.

Methods

This study queried elective total knee arthroplasty (TKA) and total hip arthroplasty (THA) cases during 2010-2018 in the American College of Surgeons National Surgical Quality Improvement Program. Artificial neural network models predicted same-day discharge and length of stay (LOS) fewer than 2 days (short LOS). Multiple linear and logistic regression analyses were used to identify variables significantly associated with predicted outcomes.

Results

A total of 284,731 TKA cases and 153,053 THA cases met inclusion criteria. For TKA, prediction of short LOS had an area under the receiver operating characteristic curve (AUC) of 0.767 and accuracy of 84.1%; prediction of same-day discharge had an AUC of 0.802 and accuracy of 89.2%. For THA, prediction of short LOS had an AUC of 0.757 and accuracy of 70.6%; prediction of same-day discharge had an AUC of 0.814 and accuracy of 78.8%.

Conclusion

This study developed machine learning models for aiding patient selection for outpatient TJA, through accurately predicting short LOS or outpatient vs inpatient cases. As outpatient TJA expands, it will be important to optimize preoperative patient selection and effectively screen surgical candidates from a broader patient population. Incorporating models such as these into electronic medical records could aid in decision-making and resource planning in real time.

Artificial Learning and Machine Learning Decision Guidance Applications in Total Hip and Knee Arthroplasty: A Systematic Review

Background

Artificial intelligence (AI) and machine learning (ML) modeling in hip and knee arthroplasty (total joint arthroplasty [TJA]) is becoming more commonplace. This systematic review aims to quantify the accuracy of current AI- and ML-based application for cognitive support and decision-making in TJA.

Methods

A comprehensive search of publications was conducted through the EMBASE, Medline, and PubMed databases using relevant keywords to maximize the sensitivity of the search. No limits were placed on level of evidence or timing of the study. Findings were reported according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Analysis of variance testing with post-hoc Tukey test was applied to compare the area under the curve (AUC) of the models.

Results

After application of inclusion and exclusion criteria, 49 studies were included in this review. The application of AI/ML-based models and average AUC is as follows: cost prediction-0.77, LOS and discharges-0.78, readmissions and reoperations-0.66, preoperative patient selection/planning-0.79, adverse events and other postoperative complications-0.84, postoperative pain-0.83, postoperative patient-reported outcomes measures and functional outcome-0.81. Significant variability in model AUC across the different decision support applications was found (P < .001) with the AUC for readmission and reoperation models being significantly lower than that of the other decision support categories.

Conclusions

AI/ML-based applications in TJA continue to expand and have the potential to optimize patient selection and accurately predict postoperative outcomes, complications, and associated costs. On average, the AI/ML models performed best in predicting postoperative complications, pain, and patient-reported outcomes and were less accurate in predicting hospital readmissions and reoperations.

Recent Trends in Medicare Utilization and Reimbursement for Orthopaedic Procedures Performed at Ambulatory Surgery Centers

BACKGROUND

As part of a market-driven response to the increasing costs of hospital-based surgical care, an increasing volume of orthopaedic procedures are being performed in ambulatory surgery centers (ASCs). The purpose of the present study was to identify recent trends in orthopaedic ASC procedure volume, utilization, and reimbursements in the Medicare system between 2012 and 2017.

METHODS

This cross-sectional, national study tracked annual Medicare claims and payments and aggregated data at the county level. Descriptive statistics and multivariate regression models were used to evaluate trends in procedure volume, utilization rates, and reimbursement rates, and to identify demographic predictors of ASC utilization.

RESULTS

A total of 1,914,905 orthopaedic procedures were performed at ASCs in the Medicare population between 2012 and 2017, with an 8.8% increase in annual procedure volume and a 10.5% increase in average reimbursements per case. ASC orthopaedic procedure utilization, including utilization across all subspecialties, is strongly associated with metropolitan areas compared with rural areas. In addition, orthopaedic procedure utilization, including for sports and hand procedures, was found to be significantly higher in wealthier counties (measured by average household income) and in counties located in the South.

CONCLUSIONS

This study demonstrated increasing orthopaedic ASC procedure volume in recent years, driven by increases in hand procedure volume. Medicare reimbursements per case have steadily risen and outpaced the rate of inflation over the study period. However, as orthopaedic practice overhead continues to increase, other Medicare expenditures such as hospital payments and operational and implant costs also must be evaluated. These findings may provide a source of information that can be used by orthopaedic surgeons, policy makers, investors, and other stakeholders to make informed decisions regarding the costs and benefits of the use of ASCs for orthopaedic procedures.

Three-Dimensional Printing for Preoperative Planning and Pedicle Screw Placement in Adult Spinal Deformity: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

This current systematic review seeks to identify current applications and surgical outcomes for 3-dimensional printing (3DP) in the treatment of adult spinal deformity.

METHODS

A comprehensive search of publications was conducted through literature databases using relevant keywords. Inclusion criteria consisted of original studies, studies with patients with adult spinal deformities, and studies focusing on the feasibility and/or utility of 3DP technologies in the planning or treatment of scoliosis and other spinal deformities. Exclusion criteria included studies with patients without adult spinal deformity, animal subjects, pediatric patients, reviews, and editorials.

RESULTS

Studies evaluating the effect of 3DP drill guide templates found higher screw placement accuracy in the 3DP cohort (96.9%), compared with non-3DP cohorts (81.5%, P < .001). Operative duration was significant decreased in 3DP cases (378 patients, 258 minutes) relative to non-3DP cases (301 patients,272 minutes, P < .05). The average deformity correction rate was 72.5% in 3DP cases (245 patients). There was no significant difference in perioperative blood loss between 3DP (924.6 mL, 252 patients) and non-3DP cases (935.6 mL, 177 patients, P = .058).

CONCLUSIONS

Three-dimensional printing is currently used for presurgical planning, patient and trainee communication and education, pre- and intraoperative guides, and screw drill guides in the treatment of scoliosis and other adult spinal deformities. In adult spinal deformity, the usage of 3DP guides is associated with increased screw accuracy and favorable deformity correction outcomes; however, average costs and production lead time are highly variable between studies.

Using machine learning methods to predict nonhome discharge after elective total shoulder arthroplasty

Background

Machine learning has shown potential in accurately predicting outcomes after orthopedic surgery, thereby allowing for improved patient selection, risk stratification, and preoperative planning. This study sought to develop machine learning models to predict nonhome discharge after total shoulder arthroplasty (TSA).

Methods

The American College of Surgeons National Surgical Quality Improvement Program database was queried for patients who underwent elective TSA from 2012 to 2018. Boosted decision tree and artificial neural networks (ANN) machine learning models were developed to predict non-home discharge and 30-day postoperative complications. Model performance was measured using the area under the receiver operating characteristic curve (AUC) and overall accuracy (%). Multivariate binary logistic regression analyses were used to identify variables that were significantly associated with the predicted outcomes.

Results

There were 21,544 elective TSA cases identified in the National Surgical Quality Improvement Program registry from 2012 to 2018 that met inclusion criteria. Multivariate logistic regression identified several variables associated with increased risk of nonhome discharge including female sex (odds ratio [OR] = 2.83; 95% confidence interval [CI] = 2.53-3.17; P < .001), age older than 70 years (OR = 3.19; 95% CI = 2.86-3.57; P < .001), American Society of Anesthesiologists classification 3 or greater (OR = 2.70; 95% CI = 2.41-2.03; P < .001), prolonged operative time (OR = 1.38; 95% CI = 1.20-1.58; P < .001), as well as history of diabetes (OR = 1.56; 95% CI = 1.38-1.75; P < .001), chronic obstructive pulmonary disease (OR = 1.71; 95% CI = 1.46-2.01; P < .001), congestive heart failure (OR = 2.65; 95% CI = 1.72-4.01; P < .001), hypertension (OR = 1.35; 95% CI = 1.20-1.52; P = .004), dialysis (OR = 3.58; 95% CI = 2.01-6.39; P = .002), wound infection (OR = 5.67; 95% CI = 3.46-9.29; P < .001), steroid use (OR = 1.43; 95% CI = 1.18-1.74; P = .010), and bleeding disorder (OR = 1.84; 95% CI = 1.45-2.34; P < .001). The boosted decision tree model for predicting nonhome discharge had an AUC of 0.788 and an overall accuracy of 90.3%. The ANN model for predicting nonhome discharge had an AUC of 0.851 and an overall accuracy of 89.9%. For predicting the occurrence of 1 or more postoperative complications, the boosted decision tree model had an AUC of 0.795 and an overall accuracy of 95.5%. The ANN model yielded an AUC of 0.788 and an overall accuracy of 92.5%.

Conclusions

Both the boosted decision tree and ANN models performed well in predicting nonhome discharge with similar overall accuracy, but the ANN had higher discriminative ability. Based on the findings of this study, machine learning has the potential to accurately predict nonhome discharge after elective TSA. Surgeons can use such tools to guide patient expectations and to improve preoperative discharge planning, with the ultimate goal of decreasing hospital length of stay and improving cost-efficiency.

Number of screws in the articular segment of distal humerus AO/OTA C-type fractures treated with open reduction internal fixation is associated with complication rate

Introduction: Surgical treatment of distal humerus fractures can lead to numerous complications. Data suggest that the number of screws in the distal (articular) segment may be associated with complication rate. The purpose of this study is to evaluate the association between a number of screws in the distal segment and complication rate for surgical treatment of distal humerus fractures. We hypothesize that the number of screws in the articular segment of distal humerus AO/OTA C-type fractures treated with open reduction internal fixation (ORIF) will be inversely proportional to the complication rate. Methods: We performed a single-center retrospective cohort study of 27 patients who underwent ORIF of distal humerus fractures C-type with at least six months of radiographic and clinical follow-up. Clinical outcomes including a range of motion, pain, revision surgery for stiffness and/or heterotopic ossification (HO), nonunion, and persistent ulnar nerve symptoms requiring revision neurolysis were recorded. Results: In C-type fractures, the use of three or fewer articular screws was significantly associated with nonunion or loss of fixation (RR 17, p = 0.006). Nineteen of 36 (53%) patients experienced at least one complication. The surgical approach, plate configuration, age, and ulnar nerve treatment (none, in situ release, transposition) were not associated with the need for revision surgery. Men had a higher risk of requiring surgical contracture release due to improving post-operative stiffness (RR 12, p = 0.02). Conclusion: In this retrospective study, the use of three or fewer screws to fix articular fragments in AO type C fractures was a significant risk for nonunion or loss of fixation. Plate configuration and surgical approach did not correlate with outcomes. Men had higher rates of complications and required more frequent revision surgery compared to women.

Recent trends in Medicare utilization and surgeon reimbursement for shoulder arthroplasty

BACKGROUND

Recent efforts to contain health care costs and move toward value-based health care have intensified, with a continued focus on Medicare expenditures, especially for high-volume procedures. As total shoulder arthroplasty (TSA) volume continues to increase, especially within the Medicare population, it is important for orthopedic surgeons to understand recent trends in the allocation of health care expenditures and potential effects on reimbursements. The purpose of this study was to evaluate trends in annual Medicare utilization and provider reimbursement rates for shoulder arthroplasty procedures between 2012 and 2017.

METHODS

This study tracked annual Medicare claims and payments to shoulder arthroplasty surgeons via publicly available databases and aggregated data at the county level. Descriptive statistics were used to evaluate trends in procedure volume, utilization rate (per 10,000 Medicare beneficiaries), and reimbursement rate. We used adjusted multiple linear regression models to examine associations between county-specific variables (ie, urban or rural, average household income, poverty rate, percentage Medicare population, and race and ethnicity demographics) and procedure volume, utilization rate, and reimbursement rate.

RESULTS

Between 2012 and 2017, there was an 81.3% increase in primary TSA volume and 55.5% increase in primary TSA utilization. The Midwest and South had higher utilization rates than the Northeast and West (P < .001). TSA utilization rates in metropolitan areas were significantly higher than in rural areas (P < .001). Utilization rates for primary TSA procedures also had a significant negative association with poverty rate (P < .001). Regarding reimbursements, the Medicare payment per TSA case decreased from 2012 to 2017, with overall inflation-adjusted decreases of 7.1% and 11.8% for primary and revision cases, respectively. TSAs performed in metropolitan areas received significantly higher reimbursements per case than TSAs performed in rural areas ($1108.05 and $1066.40, respectively; P = .002). Furthermore, reimbursements per case were on average higher in the Northeast and West than in the South and Midwest (P < .001).

CONCLUSIONS

Our study confirms that although TSA volume and per capita utilization have increased dramatically since 2012, Medicare Part B reimbursements to surgeons have continued to fall even after the adoption of bundled-payment models for orthopedic procedures. Cost-containment efforts continue to focus on Medicare reimbursements to surgeons, although other expenditures such as hospital payments and operational and implant costs must also be evaluated as part of an overall transition to value-based health care.

Recent trends in medicare utilization and reimbursement for anterior cervical discectomy and fusion

BACKGROUND CONTEXT

Anterior cervical discectomy and fusion (ACDF) has been considered the gold standard for treating various cervical spine pathologies stemming from cervical degenerative disorders. While cervical artificial disc replacement has emerged as an alternative in select cases, ACDF still remains a commonly performed procedure.

PURPOSE

This study seeks to define the costs of ACDF and identify trends and variations in ACDF volume, utilization, and surgeon and hospital reimbursement rates.

STUDY DESIGN/SETTING

Retrospective analysis of patients undergoing ACDF PATIENT SAMPLE: Medicare patients undergoing ACDF between 2012 and 2017 OUTCOME MEASURES: ACDF volume, utilization rates, and surgeon/hospital reimbursement rates METHODS: This study tracked annual Medicare claims and payments to ACDF surgeons using publicly-available databases and aggregated data at the county level. Descriptive statistics and multivariate regression models were used to evaluate trends in procedure volume, utilization rates (per 10,000 Medicare beneficiaries), and reimbursement rates, and to examine associations between county-specific variables (ie, urban or rural, average household income, poverty rate, percent Medicare population, race/ethnicity demographics), and ACDF utilization and reimbursement rates.

RESULTS

A total of 264,673 ACDF surgeries were performed in the Medicare population from 2012 to 2017, with a 24.2% increase in annual procedure volume. Utilization also increased by 6.5% from 8.0 surgeries per 10,000 Medicare beneficiaries in 2012 to 8.5 in 2017. Hospital reimbursements for cervical spine fusion surgeries without complications or co-morbidities experienced nominal and inflation-adjusted increases of 9.5% and 0.7%, respectively, from $12,030.11 in 2012 to $13,167.64 in 2017. Surgeon reimbursements for single-level and multilevel ACDF each nominally decreased from $958.11 and $1,173.01, respectively, in 2012 to $950.34 and $1,138.41 in 2017 (a 0.8% and 2.9% decrease, respectively), but after adjusting for inflation, reimbursements per case fell by an average of 8.7% and 10.7%, respectively. In contrast, mean reimbursements per case for hospitals rose by 7.1% (1.5% inflation-adjusted decrease). A significant upward yearly trend in ambulatory surgical centers volume, resulted in a net increase of 184.5% between 2015 and 2017 (p<.001).

CONCLUSIONS

While ACDF volume and utilization has continued to increase since 2012, Medicare payments to hospitals and surgeons have struggled to keep up with inflation. Our study confirms that Medicare reimbursement per case continues to decrease at a disproportionate rate for surgeons, compared to hospitals. The increasing trend in procedures performed at ambulatory surgical centers shows promise for a future model of cost-efficient and value-based care.

A Systematic Review of the Orthopedic Literature Involving National Hockey League Players

Background

Orthopedic injuries of National Hockey League (NHL) players are common and may significantly affect players’ health and careers. Evidence-based injury management is important in guiding players’ timely return to sport and their ability to play at their pre-injury levels of competition.

Purpose

To summarize all data published between January 1980 and March 2020 on orthopedic injuries experienced by professional ice hockey players competing in the NHL.

Study Design

Systematic review.

Methods

A literature review of studies examining orthopedic injuries in the NHL was performed using the Embase, PubMed, and CINAHL databases. The review included studies focusing on NHL players and players attending the NHL Combine and preseason NHL team camps. Studies pertaining to non-orthopedic injuries and case reports were excluded.

Results

A total of 39 articles met the inclusion criteria and were analyzed. The articles were divided by anatomic site of injury for further analysis: hip and pelvis (24%), general/other (14%), ankle (10%), knee (10%), foot (7%), shoulder (7%), thigh (7%), trunk (7%), spine (6%), elbow (4%), and hand and wrist (4%). The majority of articles were Level IV Evidence (51.3%), followed by Level III Evidence (38.5%). Most studies obtained data from publicly available internet resources (24.7%), player medical records (19.5%) or surveys of team physicians and athletic trainers (15.5%). A much smaller number of studies utilized the NHL Injury Surveillance System (NHLISS) (6.5%) or the Athlete Health Management System (AHMS) (2.6%).

Conclusion

This systematic review provides NHL team physicians with a single source of the current literature regarding orthopedic injuries in NHL players. Most research was published on hip and pelvis (24%) injuries, did not utilize the NHLISS and consisted of Level IV Evidence.

Recent trends in medicare utilization and reimbursement for lumbar spine fusion and discectomy procedures

BACKGROUND CONTEXT

Understanding the scope of the volume and costs of lumbar fusions and discectomy procedures, as well as identifying significant trends within the Medicare system, may be beneficial in enhancing cost-efficiency and care delivery. However, there is a paucity of studies which analyze recent trends in lumbar fusion volume, utilization, and reimbursements.

PURPOSE

This study seeks to define the costs of lumbar fusions and discectomy procedures and identify trends and variations in volume, utilization, and surgeon and hospital reimbursement rates in the Medicare system between 2012 and 2017.

STUDY DESIGN

Retrospective database study.

PATIENT SAMPLE

Medicare Part A and Part B claims submitted for lumbar spine procedures from 2012 to 2017, as documented in the Centers for Medicare & Medicaid Services Physician and Other Supplier Public Use Files.

OUTCOME MEASURES

Procedure numbers and payments per episode.

METHODS

This cross-sectional study tracked annual Medicare claims and payments to spine surgeons using publicly-available databases and aggregated data at the county level. Descriptive statistics and multivariate regression models were used to evaluate trends in procedure volume, utilization rates (per 10,000 Medicare beneficiaries), and reimbursement rates, and to examine associations between county-specific and lumbar spine procedure utilization and reimbursements.

RESULTS

A total of 772,532 lumbar spine procedures were performed in the Medicare population from 2012 to 2017, including 634,335 lumbar fusion surgeries and 138,197 primary lumbar discectomy and microdiscectomy single-level surgeries. There was a 26.0% increase in annual lumbar fusion procedure volume during the study period, with a compound annual growth rate (CAGR) of 4.7%. Lumbar discectomy/microdiscectomy experienced a 23.5% decrease in annual procedure volume (CAGR, -5.2%). Mean Medicare surgeon reimbursements for lumbar fusions nominally decreased by 3.7% from $767 in 2012 to $738 in 2017, equivalent to an inflation-adjusted decrease of 11.4% (CAGR, -0.7%). Mean Medicare payments for lumbar discectomy and microdiscectomy procedures nominally increased by 16.3% from $517 in 2012 to $601 in 2017, equivalent to an inflation-adjusted increase of 6.9% (CAGR, 3.1%).

CONCLUSIONS

This present study found the volume and utilization of lumbar fusions have increased since 2012, while lumbar discectomy and microdiscectomy volume and utilization have fallen. Medicare payments to hospitals and surgeons for lumbar fusions have either declined or not kept pace with inflation, and reimbursements for lumbar discectomy and microdiscectomy to hospitals have risen at a disproportionate rate compared to surgeon payments. These trends in Medicare payments, especially seen in decreasing allocation of reimbursements for surgeons, may be the effect of value-based cost reduction measures, especially for high-cost orthopedic and spine surgeries.

Hospital and Surgeon Medicare Reimbursement Trends for Total Joint Arthroplasty

BACKGROUND

Over 1 million total joint arthroplasties (TJAs) are performed every year in the United States, creating Medicare cost concerns for policy makers. The purpose of this study is to evaluate recent trends in Medicare utilization and reimbursements to hospitals/surgeons for TJAs between 2012 and 2017.

METHODS

We tracked annual Medicare claims and payments to TJA surgeons using publicly available Medicare databases and aggregated data at the county level. Descriptive statistics and multivariate regression models were used to evaluate trends in procedure volume, utilization (per 10,000 Medicare beneficiaries), and reimbursement rates and to examine associations between county-specific variables and TJA utilization and reimbursements.

RESULTS

Between 2012 and 2017, there was an 18.9% increase in annual primary TJA volume (357,500 cases in 2012 to 425,028 cases in 2017) and a 2.0% increase in annual primary TJA per capita utilization (73.4 cases per 10,000 Medicare beneficiaries in 2012 to 74.8 in 2017). The Midwest and the South had higher utilization rates compared with the Northeast and West (P < .001). Utilization rates for primary TJA procedures also had a significant negative association with the poverty rate (P < .001). Medicare Part B payments to surgeons fell by 7.5%, equivalent to a 14.9% inflation-adjusted decline, whereas hospital reimbursements and charges increased by 0.3% and 18.6%, respectively, during the study period.

CONCLUSIONS

Despite increasing TJA volume and utilization, surgeon reimbursements have continued to decline, whereas hospital payments and hospital charges have increased significantly more than surgeon charges. Cost containment efforts will need to address other expenditures such as hospital costs and implant costs to better align financial risks and incentives for TJA surgeons.

Outcomes of lesser tuberosity osteotomy in revision anatomic shoulder arthroplasty

BACKGROUND

Lesser tuberosity osteotomy (LTO) is a common surgical approach during anatomic shoulder arthroplasty. Outcomes of LTO have been shown to be similar to subscapularis tenotomy and peel techniques, but little is known about the outcomes of LTO during revision arthroplasty.

METHODS

This retrospective case series included 10 consecutive patients who underwent LTO during revision shoulder arthroplasty at a single institution from 2012 to 2016. Patients underwent a preoperative computed tomography scan to evaluate the lesser tuberosity bone stock. Demographic information, radiographic evidence of LTO healing, outcomes of range of motion, subscapularis strength, and visual analog scale pain scores were analyzed.

RESULTS

Revision total shoulder arthroplasty with LTO was performed for glenoid arthritis after hemiarthroplasty in 10 patients. Average age at surgery was 59.8 years, and no humeral stems were revised. Eight of 10 patients had prior subscapularis tenotomy. Average follow-up after revision surgery was 9.2 months. LTO union was documented in 80% and nondisplaced nonunion in 20%. At follow-up, 50% reported mild pain. Subscapularis strength testing was graded normal in 80% and weak in 20%. Average visual analog scale pain improved from 9.4 prerevision to 4.8 postrevision (P < .05). On average, range of motion improved in active forward elevation from 123° to 141° and remained unchanged in active external rotation from 42° to 42°.

CONCLUSION

Patients undergoing LTO during revision anatomic shoulder arthroplasty demonstrate successful LTO bony healing, improvement in pain, and improved forward elevation. In select patients not requiring humeral stem revision, LTO is a safe and effective surgical approach to subscapularis management during revision anatomic shoulder arthroplasty.

Lesser Tuberosity Osteotomy Outcomes After Anatomic Shoulder Arthroplasty in Patients With Atraumatic Avascular Necrosis

Introduction

Lesser tuberosity osteotomy (LTO) is an attractive option for subscapularis management during anatomic shoulder arthroplasty due to the biomechanical strength and reliable bone-to-bone healing. Patients with humeral head avascular necrosis (AVN) may have compromised bone healing, and the outcomes of LTO during AVN are unknown.

Methods

A retrospective consecutive case series of 6 patients with Cruess grade 4 or 5 humeral head AVN who underwent anatomic shoulder arthroplasty with LTO from 2010 to 2016 was performed. Postoperative radiographic evaluation for LTO healing at 6 months was analyzed, and clinical outcomes at latest follow-up, including range of motion (ROM), strength, and pain were studied.>

Results

Average age was 50.3 years. AVN was secondary to sickle cell in 1 patient, steroid use for systemic lupus erythematosus in 4, and chronic alcoholism in 1. By 6 months after arthroplasty, 100% had radiographically united and healed LTO. Patients averaged 140 ± 21° of active forward elevation and 42 ± 7° of active external rotation. Patients reported an improvement in visual analogue scale pain from 8.3 preoperatively to 3.8 postoperatively. All patients had a normal abdominal compression test. No patients required revision surgery.

Conclusion

The use of LTO during anatomic shoulder arthroplasty for AVN has an excellent bony healing rate with improvements in pain, ROM, and strength. The diseases that cause humeral head AVN do not negatively influence LTO healing outcomes during anatomic shoulder replacement.

Level of Evidence

IV Case Series

Total penile reconstruction: A systematic review

BACKGROUND

Phalloplasty poses a unique challenge to the plastic and reconstructive surgeon. The development of advanced microsurgical techniques has greatly augmented the range of surgical approaches available.

METHODS

A systematic review of the MEDLINE and Cochrane databases was performed to identify clinical studies of total penile reconstruction published within the last 10 years using the search algorithm: "(phallus or penis or penile) and (reconstruction or phalloplasty or transplant)".

RESULTS

The primary literature search retrieved 1400 articles. After applying inclusion and exclusion criteria, 30 studies were selected for review. The radial forearm free flap is the preferred technique for total phalloplasty; however, other techniques including the fibular osteocutaneous flap, anterolateral thigh flap, latissimus dorsi flap, scapular free flap, and abdominal flap are described. Background, indications, and preoperative and postoperative care are also discussed.

CONCLUSIONS

Total penile reconstruction can provide functional, aesthetic, and psychosocial benefits to the patient. Use of the radial forearm free flap has been proposed as the gold standard; however, the wide range of potential complications associated with phalloplasty warrants an individualized approach to each patient.

Apoptosis-stimulating protein of p53-2 (ASPP2/53BP2L) is an E2F target gene

The p53 pathway is a central apoptotic regulator. Deregulation of the Rb/E2F pathway occurs in a majority of tumors, resulting in both unrestrained proliferation and enhanced apoptosis sensitivity via p53-dependent and independent mechanisms. However, the mechanisms coupling the p53 and Rb/E2F pathways remain incompletely understood. We report that ASPP2/53BP2L, a p53/p73-binding protein that promotes p53/p73-dependent apoptosis, is an E2F target gene. The ASPP2/53BP2L promoter was identified and ectopic expression of transcription-competent E2F-1 (E2F-2 and E2F-3) stimulated an ASPP2/53BP2L promoter-luciferase reporter. Mutational analysis of the ASPP2/53BP2L promoter identified E2F-binding sites that cooperate for E2F-1 induction and basal repression of ASPP2/53BP2L. Moreover, endogenous ASPP2/53BP2L levels increased after E2F-1 expression, and E2F-1 bound the endogenous ASPP2/53BP2L promoter after chromatin immunoprecipitation. Typical for an E2F target, ASPP2/53BP2L expression was maximal in early S-phase. Thus, ASPP2/53BP2L is downstream of E2F, suggesting that it functions as a common link between the p53/p73 and Rb/E2F apoptotic pathways.

Proapoptotic p53-interacting protein 53BP2 is induced by UV irradiation but suppressed by p53

p53 is an important mediator of the cellular stress response with roles in cell cycle control, DNA repair, and apoptosis. 53BP2, a p53-interacting protein, enhances p53 transactivation, impedes cell cycle progression, and promotes apoptosis through unknown mechanisms. We now demonstrate that endogenous 53BP2 levels increase following UV irradiation induced DNA damage in a p53-independent manner. In contrast, we found that the presence of a wild-type (but not mutant) p53 gene suppressed 53BP2 steady-state levels in cell lines with defined p53 genotypes. Likewise, expression of a tetracycline-regulated wild-type p53 cDNA in p53-null fibroblasts caused a reduction in 53BP2 protein levels. However, 53BP2 levels were not reduced if the tetracycline-regulated p53 cDNA was expressed after UV damage in these cells. This suggests that UV damage activates cellular factors that can relieve the p53-mediated suppression of 53BP2 protein. To address the physiologic significance of 53BP2 induction, we utilized stable cell lines with a ponasterone A-regulated 53BP2 cDNA. Conditional expression of 53BP2 cDNA lowered the apoptotic threshold and decreased clonogenic survival following UV irradiation. Conversely, attenuation of endogenous 53BP2 induction with an antisense oligonucleotide resulted in enhanced clonogenic survival following UV irradiation. These results demonstrate that 53BP2 is a DNA damage-inducible protein that promotes DNA damage-induced apoptosis. Furthermore, 53BP2 expression is highly regulated and involves both p53-dependent and p53-independent mechanisms. Our data provide new insight into 53BP2 function and open new avenues for investigation into the cellular response to genotoxic stress.

Unusual topogenic sequence directs prion protein biogenesis

Biosynthetic studies of the prion protein (PrP) have shown that two forms of different topology can be generated from the same pool of nascent chains in cell-free translation systems supplemented with microsomal membranes. A transmembrane form is the predominant product generated in wheat germ (WG) extracts, whereas a completely translocated (secretory) form is the major product synthesized in rabbit reticulocyte lysates (RRL). An unusual topogenic sequence within PrP is now shown to direct this system-dependent difference. The actions of this topogenic sequence were independent of on-going translation and could be conferred to heterologous proteins by the engineering of a discrete set of codons. System-dependent topology conferred by addition of RRL to WG translation products suggests that this sequence interacts with one or more cytosolic factors.

Non-hydrophobic extracytoplasmic determinant of stop transfer in the prion protein

A universal feature of integral transmembrane proteins is a hydrophobic peptide segment that spans the lipid bilayer. These hydrophobic domains are important for terminating the translocation of the polypeptide chain across the membrane of the endoplasmic reticulum (a process termed stop transfer) and for integrating the protein into the bilayer. But a role for extracytoplasmic sequences in stop transfer and transmembrane integration has not previously been shown. Recently, a sequence which directs an unusual mode of stop transfer has been identified in the prion protein. This brain glycoprotein exists in two isoforms, which are identical both in primary amino-acid sequence and in containing phosphatidylinositol glycolipid linkages at their C termini, which can be cleaved by a phosphatidylinositol-specific phospholipase C9. But only one of the isoforms (PrPC) is released from cells on treatment with this phospholipase, indicating that the two isoforms have either different subcellular locations or transmembrane orientations. Consistent with this is the observation of two different topological forms in cell-free systems. An unusual topogenic sequence in the prion protein seems to direct these alternative topologies (manuscript in preparation). In the wheat-germ translation system, this sequence directs nascent chains to a transmembrane orientation; by contrast, in the rabbit reticulocyte lysate system, this sequence fails to cause stop transfer of most nascent chains. We have now investigated determinants in this unusual topogenic sequence that direct transmembrane topology, and have demonstrated that (1) a luminally disposed charged domain is required for stop transfer at the adjacent hydrophobic domain, (2) a precise spatial relationship between these domains is essential for efficient stop transfer, and (3) codons encompassing this hydrophilic extracytoplasmic domain confer transmembrane topology to a heterologous protein when engineered adjacent to the codons for a normally translocated hydrophobic domain. These results identify an unexpected functional domain for stop transfer in the prion protein and have implications for the mechanism of membrane protein biogenesis.