The Ideal Timing of Bilateral Total Knee Arthroplasty: Simultaneous Versus Staged

Objectives

The ideal timing for patients undergoing bilateral total knee arthroplasty (TKA) remains unknown. The purpose of this study was to compare 90-day outcomes between unilateral, simultaneous bilateral, and staged bilateral TKA.

Methods

The PearlDiver database was used to retrospectively identify 231,119 patients undergoing primary TKA during 2015-2020, of which 67,956 (29.4%) were bilateral. Bilateral TKA patients were divided into cohorts of simultaneous bilateral TKA and staged bilateral TKA at 1-14 days, 15-30 days, 31-90 days, and 91-365 days. Each bilateral TKA cohort underwent one-to-one matching with unilateral TKA patients based on age, gender, year, Elixhauser Comorbidity Index (ECI), and a history of obesity, diabetes, and tobacco use. Ninety-day outcomes were compared between matched groups via univariate and multivariate analysis. In staged bilateral TKA groups, outcomes were collected beginning after the second TKA.

Results

Compared to unilateral TKA, simultaneous bilateral TKA was associated with higher rates of venous thromboembolism (VTE; odds ratio [OR] 1.28, 95% confidence interval [CI] 1.07-1.54, p=0.007), acute kidney injury (AKI; OR 1.47, CI 1.17-1.84, p=0.001), blood transfusion (OR 6.81, CI 5.43-8.65, p<0.001), and any complication (OR 1.63, CI 1.49-1.78, p<0.001). Staged bilateral TKA at any time interval studied was associated with a similar or decreased risk of individual complications, emergency department visits, readmissions, reoperations, and any complication relative to unilateral TKA.

Conclusion

Simultaneous bilateral TKA is associated with an increased risk of adverse events compared to unilateral TKA. However, bilateral TKA staged at a short interval appears safe in appropriately selected patients.

Intra-articular corticosteroids associated with increased risk of total hip arthroplasty at 5 years

BACKGROUND

Intra-articular corticosteroid injections are commonly administered for hip pain. However, guidelines are conflicting on their efficacy, particularly in patients without arthritis. This study assessed for an association of corticosteroid injections and the incidence of total hip arthroplasty at 5 years.

METHODS

Patients with a diagnosis of hip pain without femoroacetabular osteoarthritis who were administered an intra-articular corticosteroid injection of the hip within a 2-year period were identified from the Mariner PearlDiver database. Patient were matched to patients with a diagnosis of hip pain who did not receive an injection. 5-year incidence of total hip arthroplasty was compared between matched patients who received an intra-articular corticosteroid injection and those who did not.

RESULTS

2,540,154 patients diagnosed with hip pain without femoroacetabular arthritis were identified. 25,073 (0.9%) patients received a corticosteroid injection and were matched to an equal number of control patients. The incidence of total hip arthroplasty (THA) at 5-year-follow up was significantly higher for the corticosteroid cohort compared to controls (1.1% vs. 0.5%; p < 0.001). The incidence and risk of THA increased along with number of injections (1 injection: 0.8%, OR 1.37; 95% CI, 1.34-1.42; p < 0.001, 2 injections: 1.1%; OR 1.45; CI, 1.40-1.50; p < 0.001, ⩾3 injections: 1.5%; OR 1.48; CI, 1.40-1.56; p < 0.001).

CONCLUSIONS

There may be a dose-dependent association of corticosteroid injections and a greater risk of total hip arthroplasty at 5 years. These results along with the conflicting guidelines on the efficacy of intra-articular steroids for hip pain should prompt physicians to consider osteoarthritis progression that may occur in the setting of corticosteroid injections in non-arthritic hips.

Outpatient Total Knee Arthroplasty Shows Decreasing Complication Burden From 2010 to 2020

BACKGROUND

The number of total knee arthroplasties (TKAs) performed on an outpatient basis continues to increase. The purpose of this study was to compare complication rates over the last decade to evaluate trends in the safety of outpatient TKA.

METHODS

Patients who underwent TKA from 2010 to 2020 from a large administrative claims database were retrospectively identified and stratified based on the year of surgery. Propensity-score matching was performed to match patients who were discharged within 24 hours of surgery to inpatients based on age, sex, comorbidity index, and year of surgery. Linear regression analyses were used to compare trends from 2010 to 2020. The 90-day adverse events in the early cohort (2010-2012) were compared to those in the late cohort (2018-2020) using multivariable regression analyses. Of the 547,137 patients in the sample, 28,951 outpatients (5.3%) were propensity matched to inpatients.

RESULTS

The incidence of outpatient TKA increased from 2010 to 2018 (1.9 versus 13.8%, P < .001). Despite a similar complication rate early (24.1 versus 22.6%, P = .164), outpatient TKA had fewer complications at the end of the study period (13.7 versus 16.7%, P < .001). Multivariate analyses demonstrated that the risk of any complication after outpatient TKA was lower than inpatient from 2018 to 2020 (odds ratio, 0.78; 95% confidence interval, 0.71-0.84).

CONCLUSIONS

Complications in both cohorts declined dramatically suggesting improvements in quality of care over time, with the greatest decline in patients undergoing outpatient surgery. These results suggest that outpatient TKA today is not higher risk for the patient than inpatient TKA.

LEVEL OF EVIDENCE

Level III.

Elective Joint Arthroplasty Should be Delayed by One Month After COVID-19 Infection to Prevent Postoperative Complications

BACKGROUND

It remains unclear whether a history of recent COVID-19 infection affects the outcomes and risks of complications of total joint arthroplasty (TJA). The purpose of this study was to compare the outcomes of TJA in patients who have and have not had a recent COVID-19 infection.

METHODS

A large national database was queried for patients undergoing total hip and total knee arthroplasty. Patients who had a diagnosis of COVID-19 within 90-days preoperatively were matched to patients who did not have a history of COVID-19 based on age, sex, Charlson Comorbidity Index, and procedure. A total of 31,453 patients undergoing TJA were identified, of which 616 (2.0%) had a preoperative diagnosis of COVID-19. Of these, 281 COVID-19 positive patients were matched with 281 patients who did not have COVID-19. The 90-day complications were compared between patients who did and did not have a diagnosis of COVID-19 at 1, 2, and 3 months preoperatively. Multivariate analyses were used to further control for potential confounders.

RESULTS

Multivariate analysis of the matched cohorts showed that COVID-19 infection within 1 month prior to TJA was associated with an increased rate of postoperative deep vein thrombosis (odds ratio [OR]: 6.50, 95% confidence interval: 1.48-28.45, P = .010) and venous thromboembolic events (odds ratio: 8.32, confidence interval: 2.12-34.84, P = .002). COVID-19 infection within 2 and 3 months prior to TJA did not significantly affect outcomes.

CONCLUSION

COVID-19 infection within 1 month prior to TJA significantly increases the risk of postoperative thromboembolic events; however, complication rates returned to baseline after that time point. Surgeons should consider delaying elective total hip arthroplasty and total knee arthroplasty until 1 month after a COVID-19 infection.

Ultrasound-Guided Iliopsoas Bursal Injections for Management of Iliopsoas Bursitis After Total Hip Arthroplasty

BACKGROUND

Iliopsoas tendonitis can cause persistent pain after total hip arthroplasty (THA). Nonoperative management of iliopsoas tendonitis includes anti-inflammatory drugs and image-guided corticosteroid injections. This study evaluated the efficacy of ultrasound-guided corticosteroid injections (US-CSIs) for iliopsoas tendonitis following THA.

METHODS

We retrospectively reviewed 42 patients who received an US-CSI for iliopsoas tendonitis after primary THA between 2009 and 2020 at a single institution. Outcomes including reoperation, groin pain at last follow-up, additional intrabursal injection, and Harris Hip Score (HHS) were evaluated at a minimum of 1 year. Cross-table lateral radiographs (36 patients) or computed tomography scans (6 patients) were reviewed to determine if anterior cup overhang was present, indicating a mechanical etiology of iliopsoas tendonitis. Descriptive statistics and univariate comparison of HHS preinjection and postinjection were performed, with alpha < 0.05.

RESULTS

Among the 22 patients who did not have cup overhang, four (18.2%) had persistent groin pain at mean follow-up of 40 months (range, 14-94) after US-CSI. Three patients had a second injection; none had groin pain at most recent follow-up. No patients required acetabular revision. Mean HHS improved from 74 points (range, 52-94 points) to 91 points (range, 76-100 points; P < .001) at last follow-up. Among the 20 patients who had anterior cup overhang, five underwent acetabular revision after only temporary pain relief from injection. Groin pain was resolved in all revised patients at mean follow-up of 43 months (range, 12-60) after revision. Of the remaining 15 patients, five had persistent groin pain at mean follow-up of 35 months (range, 12-83). Mean HHS improved from 69 points (range, 50-96 points) preinjection to 81 (range, 56-98 points; P = .007) at last follow-up.

CONCLUSION

Resolution of groin pain was demonstrated in 78.6% of patients in the cohort; however, those who did not have acetabular overhang had higher rates of success. The overall revision rate was 11.9%. US-CSI appears to be safe and effective in the diagnosis and treatment of iliopsoas tendonitis following primary THA.

LEVEL OF EVIDENCE

Level IV, Therapeutic Study.

Intra-articular corticosteroid injections are associated with a dose-dependent risk of total knee arthroplasty at 5 years

PURPOSE

Intra-articular corticosteroid injections (CSI) are used commonly for the non-operative management of patients with knee pain. Recent literature has raised concern for chondrotoxicity of CSI. The purpose of the present study is to evaluate for any dose-dependent association between CSI in non-osteoarthritic knees and subsequent total knee arthroplasty (TKA).

METHODS

The Pearl Diver database identified patients with a diagnosis of knee pain without concomitant osteoarthritis who were administered CSI over a 2-year period. Patients were compared to matched and unmatched cohorts. The primary endpoint was the incidence of TKA at 5 years. Multivariable regression analysis was used to assess CSI quantity as an independent risk factor.

RESULTS

49,443 of 986,162 (5.0%) Patients diagnosed with knee pain without concomitant knee osteoarthritis who received at least one CSI were identified. At 5 years, there was a higher incidence of TKA in the matched injection cohort relative to the non-injection matched cohort (0.26 vs 0.13%; p < 0.001) and unmatched cohort (0.26 vs. 0.10%, p < 0.001). The quantity of CSI corresponded with an increased probability of TKA at 5 years; one injection: 0.22% (OR 1.23, 95% CI [0.87-1.74], p = 0.236); two injections: 0.39% (OR 1.98 CI [1.06-3.67], p = 0.03, three or more injections: 0.49% (OR 3.22 CI [1.60-6.48], p = 0.001). The average time to TKA after one CSI was 3.03 ± 2.29 years. This time was nearly halved with three CSI (1.78 ± 0.80 years, p < 0.001).

CONCLUSIONS

Intra-articular corticosteroid injections in patients without knee osteoarthritis at the time of injection are associated with a dose-dependent risk of TKA at 5 years. CSI may not be as benign of a treatment modality as previously thought.

Mid-Flexion Instability After Total Knee Arthroplasty: Diagnosis, Implant Design, and Outcomes

Mid-flexion instability (MFI) in total knee arthroplasty refers to a distinct clinical entity where the knee is stable at full extension and 90° of flexion, but unstable somewhere between these 2 points. The presentation of MFI is often vague, and studies defining objective clinical or intraoperative measurements are limited. In this review, we aim to properly define the condition, describe diagnostic criteria and risk factors contributing to MFI, review current implant design, and present outcomes of revision surgery performed for MFI. [Orthopedics. 2023;46(1):e13-e19.].

Complications and costs of patellofemoral arthroplasty versus total knee arthroplasty

BACKGROUND

Patellofemoral arthroplasty (PFA) is an alternative to total knee arthroplasty (TKA) for the treatment of patellofemoral arthritis. Although PFA may preserve native kinematics and accelerate recovery, it has been associated with higher revision rates. The purpose of this study is to compare complication rates and costs between PFA and TKA.

METHODS

Using the PearlDiver database, 6,179 patients with isolated patellofemoral arthritis treated with PFA or TKA from 2010-2015 were retrospectively reviewed with 5-year follow up. PFA and TKA patients were matched by age, sex, and Elixhauser Comorbidity Index via a 1:1 stepwise algorithm. Five-year costs and complications were compared between matched cohorts. The lifetime costs of PFA and TKA were evaluated with Markov decision modeling.

RESULTS

Compared to TKA, PFA was associated with fewer Emergency Department (ED) visits (6.1% vs 3.9%, p = 0.004) but a higher 5-year revision rate (9.9% vs 4.2%, p < 0.001). After multivariate regression, PFA was independently more likely to require revision (odds ratio 2.60, 95% confidence interval 1.32-4.71, p = 0.003). PFA was associated with lower total healthcare costs at every time point between 3 months ($18,014 vs $26,473, p < 0.001) and 5 years ($20,837 vs $27,942, p < 0.001). On average, the lifetime cost of PFA per patient was $5,235 less than for TKA ($26,343 vs $31,578).

CONCLUSIONS

PFA is a less expensive alternative to TKA with a similar risk of medical complications but is associated with a significantly higher 5-year revision rate. Future studies should examine the reasons for PFA failure and methods to mitigate this risk.

Over Half of All Medicare Total Knee Arthroplasty Patients Are Now Classified as an Outpatient-Three-Year Impact of the Removal From the Inpatient-Only List

BACKGROUND

In 2018, Centers for Medicare & Medicaid Services removed total knee arthroplasty (TKA) from its inpatient-only list, triggering many unintended consequences. The purpose of this study was to determine how the impact of TKA removal affected the number of outpatient TKA patients, which patients were being labeled outpatient, and how outpatient classification affected discharge location and readmission rates.

METHODS

Using a large administrative claims database, we reviewed a consecutive series of 216,365 primary TKA Medicare patients from 2015 to 2020. Patients who had an inpatient status (n = 63,356) were compared to patients who had an outpatient status (n = 38,510) from 2018 to 2020 based on demographics, comorbidities, discharge dispositions, and readmissions.

RESULTS

In 2015, only 1.8% of TKA patients were designated as outpatients, but by 2020, 57.2% of Medicare TKA patients were classified as outpatients. A majority of patients (72%) who had an outpatient designation remained in the hospital for >24 hours (average length of stay was 2.7 days). Patients who had an outpatient status were discharged to skilled nursing facilities more frequently than patients who had an inpatient status (3.1 versus 2.0%, P < .001) with increased emergency visits (5.1 versus 3.9%, P < .001) and 90-day readmissions (2.2 versus 0.9%, P < .001).

CONCLUSION

Over half of all Medicare TKA patients are being classified as outpatients 3 years following the policy to remove TKA from the inpatient-only list. Patients designated as outpatients had higher readmissions than those designated as inpatients. This policy should be re-evaluated in the context of failure to demonstrate safer discharge of Medicare patients who undergo TKA.

Contralateral Total Hip Arthroplasty Staged Within Six Weeks Increases the Risk of Adverse Events Compared to Unilateral Surgery

BACKGROUND

The ideal timing for bilateral total hip arthroplasty (THA) remains controversial. This study compared 90-day outcomes after simultaneous bilateral THA and contralateral surgery in staged bilateral THA to a matched cohort of unilateral procedures.

METHODS

Patients undergoing primary, elective THA during 2015 to 2020 were reviewed in a national database. Of the 273,281 patients identified, 39,905 (14.6%) were bilateral. Patients were divided into cohorts of unilateral THA, simultaneous bilateral THA, and staged bilateral THA at 1 to 14 days, 15 to 42 days, 43 to 90 days, and 91 to 365 days. Bilateral THA cohorts were matched with unilateral THA patients based on demographics and comorbidities. Ninety-day outcomes after the second THA were compared between matched groups.

RESULTS

Simultaneous bilateral THA resulted in higher rates of transfusion (odds ratio [OR] 4.43, 95% confidence interval 2.31-2.63, P < .001), readmission (OR 2.60, 2.01-3.39, P < .001), and any complication (OR 1.86, 1.55-2.24, P < .001) compared to unilateral THA. Contralateral THA staged at 1 to 14 days increased the risk of readmission (OR 1.83, 1.49-2.24, P < .001) and any complication (OR 1.45, 1.26-1.66, P < .001) relative to unilateral THA. Contralateral THA staged at 15 to 42 days increased the risk of periprosthetic joint infection (OR 3.15, 1.98-5.19, P < .001), readmission (OR 1.92, 1.55-2.39, P < .001), and any complication (OR 1.70, 1.46-1.97, P < .001). Contralateral THA staged beyond 42 days resulted in similar or decreased rates of adverse events relative to unilateral THA.

CONCLUSIONS

Bilateral THA should be staged a minimum of 6 weeks apart in appropriately selected patients to avoid an increased risk of adverse events after the second THA compared to unilateral THA.

A validated preoperative risk prediction tool for extended inpatient length of stay following anatomic or reverse total shoulder arthroplasty

BACKGROUND

Recent work has shown inpatient length of stay (LOS) following shoulder arthroplasty to hold the second strongest association with overall cost (after implant cost itself). In particular, a preoperative understanding for the patients at risk of extended inpatient stays (≥3 days) can allow for counseling, optimization, and anticipating postoperative adverse events.

METHODS

A multicenter retrospective review was performed of 5410 anatomic (52%) and reverse (48%) total shoulder arthroplasties done at 2 large, tertiary referral health systems. The primary outcome was extended inpatient LOS of at least 3 days, and over 40 preoperative sociodemographic and comorbidity factors were tested for their predictive ability in a multivariable logistic regression model based on the patient cohort from institution 1 (derivation, N = 1773). External validation was performed using the patient cohort from institution 2 (validation, N = 3637), including area under the receiver operator characteristic curve (AUC), sensitivity, specificity, and positive and negative predictive values.

RESULTS

A total of 814 patients, including 318 patients (18%) in the derivation cohort and 496 patients (14%) in the validation cohort, experienced an extended inpatient LOS of at least 3 days. Four hundred forty-five (55%) were discharged to a skilled nursing or rehabilitation facility. Following parameter selection, a multivariable logistic regression model based on the derivation cohort (institution 1) demonstrated excellent preliminary accuracy (AUC: 0.826), with minimal decrease in accuracy under external validation when tested against the patients from institution 2 (AUC: 0.816). The predictive model was composed of only preoperative factors, in descending predictive importance as follows: age, marital status, fracture case, ASA (American Society of Anesthesiologists) score, paralysis, electrolyte disorder, body mass index, gender, neurologic disease, coagulation deficiency, diabetes, chronic pulmonary disease, peripheral vascular disease, alcohol dependence, psychoses, smoking status, and revision case.

CONCLUSION

A freely-available, preoperative online clinical decision tool for extended inpatient LOS (≥ 3 days) after shoulder arthroplasty reaches excellent predictive accuracy under external validation. As a result, this tool merits consideration for clinical implementation, as many risk factors are potentially modifiable as part of a preoperative optimization strategy.

Single-Stage Revision of Infected Total Femoral Replacement

We present 2 cases of infected total femur prosthetic devices treated with a single-stage revision with extensive irrigation and debridement, followed by reimplantation with a prosthesis coated in antibiotic-impregnated cement. Single-stage total femoral replacement with antibiotic-eluting cement around the device was used for 2 cases of limb salvage arthroplasty to reduce complications, maintain patient function, and minimize hospital-associated cost. [Orthopedics. 2022;45(5):e280-e283.].

Home Health Care in Medicare-Aged Patients is Associated With Increased Early Emergency Visits, Readmissions, and Costs Following Total Knee Arthroplasty

BACKGROUND

Home health services are utilized in order to provide at-home care following total knee arthroplasty (TKA). The purpose of this study is to determine whether patients receiving home health services post-operatively had lower rates of complications, emergency room visits, and readmissions as well as to determine if home health provided value by reducing total episode-of-care costs.

METHODS

The PearlDiver database was retrospectively reviewed to identify all primary TKA patients over 65 years old from 2010 to 2018. Patients who received home health services were matched using a propensity score algorithm to a set of similar patients who were discharged home under self-care. We compared complication rates, emergency room visits, readmissions, and 90-day episode-of-care claims costs between the groups. Multivariate regression analysis was performed to determine the independent effect of home health services on emergency department (ED) visits and hospital readmissions.

RESULTS

Of the 185,444 TKA patients discharged home, 15,849 (8.5%) received home health services. Patients who received home health services had higher rates of ED visits at 2 weeks (3.3% vs 2.8%, P = .014) and 3 months (7.1% vs 6.5%, P = .038) as well as increased readmissions at 2 weeks (0.9% vs 0.7%, P = .028); complication rates were similar between groups (11.4% vs 10.9%, P = .159). Episode-of-care costs for home health patients were higher than those discharged under self-care ($24,266 vs $22,539, P < .001).

CONCLUSION

Home health services do not appear to provide value as they are associated with significantly increased costs and do not lower the rates of complications, ED visits, or readmissions following TKA.

Adult Reconstruction Fellowship: What is Important to the Applicants?

Background

Orthopaedic surgery trainees who aim to specialize in total joint arthroplasty commonly complete an additional year of fellowship training. Limited information regarding individual programs is readily available to potential applicants. The purpose of this study is to determine what information applicants value when considering an adult reconstruction fellowship program.

Methods

An anonymous survey was distributed to all 470 junior members of AAHKS. The 12-question survey gathered demographic information as well as average weighted scores (1-10) of various components regarding fellowship education, recruitment, and experiences. Subgroup analysis was performed on survey responses based on the following 3 different categories: Gender, year of training, and geographical location.

Results

A total of 135 respondents completed the survey (135 of 470, 28.7% response rate). Sixty-two (45.9%) participants held the position of postgraduate year 5, 43 (31.9%) participants held the position of postgraduate year 4. Exposure to operative techniques in revision surgery (9.62), exposure to operative techniques in primary surgery (9.51), and ability to obtain desired job opportunity after fellowship (8.89) were the 3 most considered components. Higher level trainees valued information regarding average number of hours worked relative to junior trainees (P = .046). Geographic differences were noted in the following 3 variables: the number of cases performed (P = .010), whether fellows had a dedicated clinic and/or operating room (P = .002), and the average number of hours worked (P = .020).

Conclusions

Amongst the 3 domains studied, applicants most valued educational components, such as exposure to various techniques surrounding total joint arthroplasty. There is a need for a centralized, comprehensive database that contains information applicants value most and this database should be customizable toward training level and location.

Preoperative Opioids and the Dose-Dependent Effect on Outcomes After Total Hip Arthroplasty

BACKGROUND

The purpose of this study is to identify the preoperative daily opioid dose associated with increased complications after primary total hip arthroplasty (THA).

METHODS

Primary THA patients in the Humana claims database (2007-2020) with an opioid prescription within 3 months prior to surgery were identified. Patients were stratified based on daily opioid dose: Tier 1, <5 milligram morphine equivalents (MME); Tier 2, 5-10 MME; Tier 3, 11-25 MME; Tier 4, 26-50 MME; Tier 5, >50 MME. Each tier was matched 1:1 to opioid-naïve patients. Emergency department (ED) visits, readmissions, and postoperative complications were compared.

RESULTS

In total, 67,719 patients using preoperative opioids were identified and matched. 17.0% of patients using preoperative opioids visited the ED within 90 days, compared to 13.3% of opioid-naïve patients (P < .001). About 9.5% of patients using preoperative opioids were readmitted within 90 days, compared to 7.4% of opioid-naïve patients (P < .001). When stratified by tier, opioid users in all tiers had higher risk of ED visits and readmission. Rates of superficial infection, periprosthetic joint infection, and dislocation were increased in patients taking preoperative opioids in Tiers 2 through 5. Patients in Tiers 3 through 5 had an increased risk of revision surgery.

CONCLUSION

Preoperative opioid use is associated with a dose-dependent increase in complications after THA. Just one 5 mg hydrocodone tablet daily leads to a significant increase in ED visits and readmission, while higher doses are associated with dislocation, superficial infection, periprosthetic joint infection, and revision surgery. Continued education regarding the harmful effects of opioids prescribed for the nonoperative treatment of osteoarthritis is still needed.

LEVEL OF EVIDENCE

Level III.

The Cost-Effectiveness of Tibial Metaphyseal Cones in Revision Total Knee Arthroplasty

BACKGROUND

The purpose of this study is to evaluate the cost-effectiveness of tibial cones in revision total knee arthroplasty.

METHODS

A Markov model was used for cost-effectiveness analysis. The average cone price was obtained from Orthopedic Network News. The average cone aseptic loosening rate was determined by literature review. Hospitalization costs and baseline re-revision rates were calculated using the PearlDiver Database.

RESULTS

The maximum cost-effective cone price varied from $3514 at age 40 to $648 at age 90, compared to the current average selling price of $4201. Cones became cost-effective with baseline aseptic loosening rates of 0.89% annually at age 40 to 4.38% annually at age 90, compared to the current average baseline loosening rate of 0.76% annually.

CONCLUSION

For the average patient, tibial cones are not cost-effective, but may become so at lower prices, in younger patients, or in patients at substantially increased risk of aseptic loosening.

A validated preoperative risk prediction tool for discharge to skilled nursing or rehabilitation facility following anatomic or reverse shoulder arthroplasty

BACKGROUND

As bundled payment models continue to spread, understanding the primary drivers of cost excess helps providers avoid penalties and ensure equal health care access. Recent work has shown discharge to rehabilitation and skilled nursing facilities (SNFs) to be a primary cost driver in total joint arthroplasty, and an accurate preoperative risk calculator for shoulder arthroplasty would not only help counsel patients in clinic during shared decision-making conversations but also identify high-risk individuals who may benefit from preoperative optimization and discharge planning.

METHODS

Anatomic and reverse total shoulder arthroplasty cohorts from 2 geographically diverse, high-volume centers were reviewed, including 1773 cases from institution 1 (56% anatomic) and 3637 from institution 2 (50% anatomic). The predictive ability of a variety of candidate variables for discharge to SNF/rehabilitation was tested, including case type, sociodemographic factors, and the 30 Elixhauser comorbidities. Variables surviving parameter selection were incorporated into a multivariable logistic regression model built from institution 1's cohort, with accuracy then validated using institution 2's cohort.

RESULTS

A total of 485 (9%) shoulder arthroplasties overall were discharged to post-acute care (anatomic: 6%, reverse: 14%, P < .0001), and these patients had significantly higher rates of unplanned 90-day readmission (5% vs. 3%, P = .0492). Cases performed for preoperative fracture were more likely to require post-acute care (13% vs. 3%, P < .0001), whereas revision cases were not (10% vs. 10%, P = .8015). A multivariable logistic regression model derived from the institution 1 cohort demonstrated excellent preliminary accuracy (area under the receiver operating characteristic curve [AUC]: 0.87), requiring only 11 preoperative variables (in order of importance): age, marital status, fracture, neurologic disease, paralysis, American Society of Anesthesiologists physical status, gender, electrolyte disorder, chronic pulmonary disease, diabetes, and coagulation deficiency. This model performed exceptionally well during external validation using the institution 2 cohort (AUC: 0.84), and to facilitate convenient use was incorporated into a freely available, online prediction tool. A model built using the combined cohort demonstrated even higher accuracy (AUC: 0.89).

CONCLUSIONS

This validated preoperative clinical decision tool reaches excellent predictive accuracy for discharge to SNF/rehabilitation following shoulder arthroplasty, providing a vital tool for both patient counseling and preoperative discharge planning. Further, model parameters should form the basis for reimbursement legislation adjusting for patient comorbidities, ensuring no disparities in access arise for at-risk populations.

National Trends in Post-Acute Care Costs Following Total Hip Arthroplasty from 2010 through 2018

BACKGROUND

Post-acute care remains a target for episode-of-care cost reduction following total hip arthroplasty (THA). The introduction of bundled payment models in the United States in 2013 aligned incentives among providers to reduce post-acute care resource utilization. Institution-level studies have shown increased rates of home discharge with substantial cost savings after adoption of bundled payment models; however, national data have yet to be reported. The purpose of this study was to evaluate national trends in post-acute care utilization and costs following primary THA over the last decade.

METHODS

We reviewed the cases of 189,847 patients undergoing primary THA during 2010 through 2018 from the PearlDiver database. Annual trends in patient demographics, discharge disposition, and post-acute care resource utilization were evaluated. Post-acute care reimbursements were standardized to 2020 dollars and included outpatient visits, prescriptions, physical therapy, home health, inpatient rehabilitation, skilled nursing facilities, and any rehospitalizations or emergency department (ED) visits within 90 days of surgery.

RESULTS

From 2010 to 2018, the mean episode-of-care costs ($31,562 versus $24,188; p < 0.001) and overall post-acute care costs ($5,903 versus $3,485; p < 0.001) both declined. Post-acute care savings were primarily driven by reduced costs of skilled nursing facilities ($1,533 versus $627; p < 0.001), home health ($1,041 versus $763; p = 0.002), inpatient rehabilitation ($949 versus $552; p < 0.001), ED visits ($508 versus $102; p < 0.001), and rehospitalizations ($367 versus $179; p < 0.001). Post-acute care costs declined by $578 (p = 0.025) during 2010 to 2012, $768 (p = 0.038) during 2013 to 2015, and $884 (p = 0.020) during 2016 to 2018.

CONCLUSIONS

Over the last decade, the rate of home discharge after THA increased while rehospitalization and ED visit rates declined, resulting in a substantial decrease in total and post-acute care costs. Post-acute care costs declined most rapidly after the introduction of the new Medicare bundled payment programs in 2013 and 2016.

Appropriate patient selection for outpatient shoulder arthroplasty: a risk prediction tool

BACKGROUND

The transition from inpatient to outpatient shoulder arthroplasty critically depends on appropriate patient selection, both to ensure safety and to counsel patients preoperatively regarding individualized risk. Cost and patient demand for same-day discharge have encouraged this transition, and a validated predictive tool may help decrease surgeon liability for complications and help select patients appropriate for same-day discharge. We hypothesized that an accurate predictive model could be created for short inpatient length of stay (discharge at least by postoperative day 1), potentially serving as a useful proxy for identifying patients appropriate for true outpatient shoulder arthroplasty.

METHODS

A multicenter cohort of 5410 shoulder arthroplasties (2805 anatomic and 2605 reverse shoulder arthroplasties) from 2 geographically diverse, high-volume health systems was reviewed. Short inpatient stay was the primary outcome, defined as discharge on either postoperative day 0 or 1, and 49 patient outcomes and factors including the Elixhauser Comorbidity Index, sociodemographic factors, and intraoperative parameters were examined as candidate predictors for a short stay. Factors surviving parameter selection were incorporated into a multivariable logistic regression model, which underwent internal validation using 10,000 bootstrapped samples.

RESULTS

In total, 2238 patients (41.4%) were discharged at least by postoperative day 1, with no difference in rates of 90-day readmission (3.5% vs. 3.3%, P = .774) between cohorts with a short length of stay and an extended length of stay (discharge after postoperative day 1). A multivariable logistic regression model demonstrated high accuracy (area under the receiver operator characteristic curve, 0.762) for discharge by postoperative day 1 and was composed of 13 variables: surgery duration, age, sex, electrolyte disorder, marital status, American Society of Anesthesiologists score, paralysis, diabetes, neurologic disease, peripheral vascular disease, pulmonary circulation disease, cardiac arrhythmia, and coagulation deficiency. The percentage cutoff maximizing sensitivity and specificity was calculated to be 47%. Internal validation showed minimal loss of accuracy after bias correction for overfitting, and the predictive model was incorporated into a freely available online tool to facilitate easy clinical use.

CONCLUSIONS

A risk prediction tool for short inpatient length of stay after shoulder arthroplasty reaches very good accuracy despite requiring only 13 variables and was derived from an underlying database with broad geographic diversity in the largest institutional shoulder arthroplasty cohort published to date. Short inpatient length of stay may serve as a proxy for identifying patients appropriate for same-day discharge, although perioperative care decisions should always be made on an individualized and holistic basis.

Characteristics and risk factors for 90-day readmission following shoulder arthroplasty

BACKGROUND

Anatomic total shoulder arthroplasty (TSA) and reverse TSA are the standard of care for end-stage shoulder arthritis. Advancements in implant design, perioperative management, and patient selection have allowed shorter inpatient admissions. Unplanned readmissions remain a significant complication. Identification of risk factors for readmission is prudent as physicians and payers prepare for the adoption of bundled care reimbursement models. The purpose of this study was to identify characteristics and risk factors associated with readmission following shoulder arthroplasty using a large, bi-institutional cohort.

METHODS

A total of 2805 anatomic TSAs and 2605 reverse TSAs drawn from 2 geographically diverse, tertiary health systems were examined for unplanned inpatient readmissions within 90 days following the index operation (primary outcome). Forty preoperative patient sociodemographic and comorbidity factors were tested for their significance using both univariable and multivariable logistic regression models, and backward stepwise elimination selected for the most important associations for 90-day readmission. Readmissions were characterized as either medical or surgical, and subgroup analysis was performed. A short length of stay (discharge by postoperative day 1) and discharge to a rehabilitation or skilled nursing facility were also examined as secondary outcomes. Parameters associated with increased readmission risk were included in a predictive model.

RESULTS

Within 90 days of surgery, 175 patients (3.2%) experienced an unanticipated readmission, with no significant difference between institutions (P = .447). There were more readmissions for surgical complications than for medical complications (62.9% vs. 37.1%, P < .001). Patients discharged to a rehabilitation or skilled nursing facility were significantly more likely to be readmitted (13.1% vs. 8.8%, P = .049), but a short inpatient length of stay was not associated with an increased rate of 90-day readmission (42.9% vs. 41.3%, P = .684). Parameter selection based on predictive ability resulted in a multivariable logistic regression model composed of 16 preoperative patient factors, including reverse TSA, revision surgery, right-sided surgery, and various comorbidities. The area under the receiver operator characteristic curve for this multivariable logistic regression model was 0.716.

CONCLUSION

Risk factors for unplanned 90-day readmission following shoulder arthroplasty include reverse shoulder arthroplasty, surgery for revision and fracture, and right-sided surgery. Additionally, there are several modifiable and nonmodifiable risk factors that can be used to ascertain a patient's readmission probability. A shorter inpatient stay is not associated with an increased risk of readmission, whereas discharge to post-acute care facilities does impose a greater risk of readmission. As scrutiny around health care cost increases, identifying and addressing risk factors for readmission following shoulder arthroplasty will become increasingly important.

Short stay after shoulder arthroplasty does not increase 90-day readmissions in Medicare patients compared with privately insured patients

BACKGROUND

As of January 1, 2021, total shoulder arthroplasty was removed from the Medicare inpatient-only list, reflecting a growing belief in the potential merits of same-day discharge regardless of insurance type. It is yet unknown whether Medicare populations, which frequently have more severe comorbidity burdens, would experience higher complication rates relative to privately insured patients, who are often younger with fewer comorbidities. Given the limited number of true outpatient cohorts available to study, discharge at least by postoperative day 1 may serve as a useful proxy for true same-day discharge, and we hypothesized that these Medicare patients would have increased 90-day readmission rates compared with their privately insured counterparts.

METHODS

Data on 4723 total shoulder arthroplasties (anatomic in 2459 and reverse in 2264) from 2 large, geographically diverse health systems in patients having either Medicare or private insurance were collected. The unplanned 90-day readmission rate was the primary outcome, and patients were stratified into those who were discharged at least by postoperative day 1 (short inpatient stay) and those who were not. Patients with private insurance (n = 1845) were directly compared with those with Medicare (n = 2878), whereas cohorts of workers' compensation (n = 198) and Medicaid (n = 58) patients were analyzed separately. Forty preoperative variables were examined to compare overall health burden, with the χ² and Wilcoxon rank sum tests used to test for statistical significance.

RESULTS

Medicare patients undergoing short-stay shoulder arthroplasty were not significantly more likely than those with private insurance to experience an unplanned 90-day readmission (3.6% vs. 2.5%, P = .14). This similarity existed despite a substantially worse comorbidity burden in the Medicare population (P < .05 for 26 of 40 factors). Furthermore, a short inpatient stay did not result in an increased 90-day readmission rate in either Medicare patients (3.6% vs. 3.4%, P = .77) or their privately insured counterparts (2.5% vs. 2.4%, P = .92). Notably, when the analysis was restricted to a single insurance type, readmission rates were significantly higher for reverse shoulder arthroplasty compared with total shoulder arthroplasty (P < .001 for both), but when the analysis was restricted to a single procedure (anatomic or reverse), readmission rates were similar between Medicare and privately insured patients, whether undergoing a short or extended length of stay.

CONCLUSIONS

Despite a substantially more severe comorbidity profile, Medicare patients undergoing short-stay shoulder arthroplasty did not experience a significantly higher rate of unplanned 90-day readmission relative to privately insured patients. A higher incidence of reverse shoulder arthroplasty in Medicare patients does increase their overall readmission rate, but a similar increase also appears in privately-insured patients undergoing a reverse indicating that Medicare populations may be similarly appropriate for accelerated-care pathways.

Daily Dose of Preoperative Opioid Prescriptions Affects Outcomes After Total Knee Arthroplasty

BACKGROUND

The use of preoperative opioids is associated with complications after total knee arthroplasty (TKA), but the dosing threshold that constitutes this risk is not known. The purpose of this study was to identify the preoperative daily opioid dose associated with increased complications after primary TKA.

METHODS

Patients who underwent primary TKA in the Humana claims database (2007-2016) with an opioid prescription within 3 months before surgery were identified. All opioids prescribed within 3 months before TKA were converted to milligram morphine equivalents. Patients were stratified based on daily opioid dose: tier 1) <10, tier 2) 10-25, tier 3) 25-50, tier 4) >50 milligram morphine equivalents. Patients were matched to opioid-naïve patients by comorbidities, age, and gender. Emergency department (ED) visits, readmissions, and surgical complications were compared.

RESULTS

A total of 20,019 patients using preoperative opioids were identified and matched. ED visits and readmissions within 90 days were significantly higher in opioid users in all tiers (relative risk (RR) of ED visit: 1.25, 1.28, 1.34, and 1.25, respectively; readmission: 1.13, 1.17, 1.22, and 1.19, respectively). Rates of prosthetic joint infection were increased in opioid users in tiers 2, 3, and 4, and the risk increased in a dose-dependent manner (RR 1.37, 1.39, and 1.50, respectively). Patients in tier 4 had an increased risk of revision surgery (RR 1.44) at 2 years.

CONCLUSION

Preoperative opioid use is associated with a dose-dependent increase in postoperative complications after TKA. Just two 5mg hydrocodone tablets daily lead to increased ED visits and readmission. Higher doses are associated with an increased risk of prosthetic joint infection and revision surgery.

National Trends in Post-Acute Care Costs Following Total Knee Arthroplasty From 2007 to 2016

BACKGROUND

Post-acute care continues to represent a target for cost savings with increasing popularity of value-based payment models in total knee arthroplasty (TKA). Rapid recovery and accelerated rehabilitation protocols have been successful in reducing costs at the institutional level, but national trends are less clear. This study aimed to determine if advancements in perioperative care led to a reduction in post-acute care costs and resource utilization following TKA.

METHODS

We reviewed a consecutive series of 79,843 primary TKA patients from the Humana claims dataset from 2007 to 2016. Post-acute care costs included any claims within 90 days of surgery for subacute or inpatient rehabilitation, home health, outpatient or emergency visits, prescription medications, physical therapy, and readmissions. Demographics, episode-of-care and post-acute care costs, readmissions, and discharge disposition were compared. Controlling for demographics and comorbidities, multivariate regression analyses were performed to compare trends in discharge disposition and post-acute care costs.

RESULTS

From 2007 to 2016, the average episode-of-care costs ($46,754 vs $31,856) and post-acute care costs per patient decreased ($20,224 vs $13,498). Rates of discharge to skilled nursing facilities (25.0% vs 22.5%) and inpatient rehabilitation also declined (12.4% vs 2.1%). Readmissions also decreased (8.1% vs 7.1%) saving an average of $324 per patient. When compared to 2007-2012, total costs declined most rapidly after 2013 primarily due to a $3516 (21%) decrease in post-acute spending.

CONCLUSION

There has been a substantial decline in post-acute care costs and resource utilization following TKA, with the largest decrease occurring following the introduction of Medicare bundled payment models in 2013.

Preoperative Corticosteroid Injections Demonstrate a Temporal and Dose-Dependent Relationship with the Rate of Postoperative Infection Following Total Hip Arthroplasty

BACKGROUND

Corticosteroid injections (CSI) are commonly used for the treatment of osteoarthritis of the hip. There is concern, however, that these injections may increase the risk of postoperative infection if a subsequent total hip arthroplasty (THA) is performed. The purpose of the present investigation is to determine the relationship between CSI and the risk of periprosthetic joint infection (PJI) and surgical site infections (SSIs) following THA.

METHODS

The PearlDiver database was reviewed for patients undergoing THA from 2011 to 2018. Patients with unilateral hip osteoarthritis who received an intra-articular hip CSI prior to ipsilateral THA were matched in a sequential 1:1 fashion based on age, gender, and Charlson Comorbidity Index with THA patients who did not receive an injection in the preoperative period. PJI and SSI within 6 months of the surgical procedure were recorded. Statistical analysis included chi-squared test and multivariate logistic regression. Results were considered significant at P < .05.

RESULTS

In total, 29,058 patients underwent a hip CSI within 6 months prior to THA. CSI within 4 months of surgery was associated with a higher incidence of PJI at 6-month follow up (1.6% vs 1.1%, P = .040). An injection within 1 month of surgery corresponded to a higher odds of PJI (odds ratio [OR] 1.97) than an injection 4 months prior to surgery (OR 1.24). Furthermore, the quantity of CSI administered within the 3 months prior to THA demonstrated a dose-dependent relationship, with each subsequent injection increasing odds of PJI (OR 1.45-3.59). A similar relationship was observed for SSI.

CONCLUSION

There appears to be both a time and dose-dependent association of hip CSI and PJI following THA. Surgeons should consider delaying elective THA if a CSI has been administered within the 4 months prior to the planned procedure.

Adipose-Derived Mesenchymal Stem Cell Treatments and Available Formulations

PURPOSE OF REVIEW

The use of human adipose-derived mesenchymal stem cells (ADSCs) has gained attention due to its potential to expedite healing and the ease of harvesting; however, clinical evidence is limited, and questions concerning optimal method of delivery and long-term outcomes remain unanswered.

RECENT FINDINGS

Administration of ADSCs in animal models has been reported to aid in improved healing benefits with enhanced repair biomechanics, superior gross histological appearance of injury sites, and higher concentrations of growth factors associated with healing compared to controls. Recently, an increasing body of research has sought to examine the effects of ADSCs in humans. Several available processing techniques and formulations for ADSCs exist with evidence to suggest benefits with the use of ADSCs, but the superiority of any one method is not clear. Evidence from the most recent clinical studies available demonstrates promising outcomes following treatment of select musculoskeletal pathologies with ADSCs despite reporting variability among ADSCs harvesting and processing; these include (1) healing benefits and pain improvement for rotator cuff and Achilles tendinopathies, (2) improvements in pain and function in those with knee and hip osteoarthritis, and (3) improved cartilage regeneration for osteochondral focal defects of the knee and talus. The limitation to most of this literature is the use of other therapeutic biologics in combination with ADSCs. Additionally, many studies lack control groups, making establishment of causation inappropriate. It is imperative to perform higher-quality studies using consistent, predictable control populations and to standardize formulations of ADSCs in these trials.

Trapezoidal Achilles Tendon Allograft Plug for Revision Quadriceps Tendon Repair With a Large Tendon Defect

Revision quadriceps tendon repair presents a challenging problem for the treating surgeon because of associated anatomic defects such as large tendon-gap deficits and preexistent poor tissue quality. Current methods for revision quadriceps tendon repair use tendon autograft, which may predispose to additional morbidity because the repair relies only on soft tissue fixation. In this Technical Note, we describe a technique for revision of a failed quadriceps tendon repair with a large tendon gap using a trapezoidal plug Achilles tendon allograft. This technique constitutes a safe and effective approach to revising failed primary quadriceps tendon repairs, is suitable for large-gap defects, and has the ability to withstand large force transmissions.

Intra-Articular Pathology Associated with Acute and Chronic Anterior Cruciate Ligament Reconstruction

BACKGROUND

Concomitant meniscal and chondral pathology is common at the time of anterior cruciate ligament reconstruction (ACL-R). The purpose of the present study was to report the prevalence of concomitant intra-articular pathology for patients undergoing acute or chronic anterior cruciate ligament reconstruction.

METHODS

This study represents a prospective, consecutively collected cohort of 255 patients undergoing both primary and revision ACL-R between January 2012 and December 2014 at a single institution. The cohort was divided into an acute surgical group, defined as surgery within six weeks of injury, and a chronic surgical group, greater than six weeks removed from injury. The median time from injury to surgery for the entire cohort was 37 days (range: 4 days to 855 days). Variables of interest included patient demographic characteristics, concomitant meniscal and chondral pathology, and meniscus treatment.

RESULTS

Patients treated in the chronic setting were slightly older (28.7 ± 11.6 years vs. 23.1 ± 8.6 years, P=0.001), had a higher prevalence of complex tears of the medial meniscus (37.2% vs. 7.7%, P=0.012) and cartilage injury (16.5% vs. 7.8%, P=0.03). After excluding revision ACL-R procedures, complex medial meniscus tears in chronic ACL-R were higher than in acute ACL-R (medial= 27.3% vs. 3.0%, P=0.022), however when age was considered, these tears were no longer more frequent than in the acute setting (P=0.056). Similarly, the prevalence of cartilage injury was equivalent between groups after correcting for age (P=0.167). Among primary ACL-R, there were more medial meniscus repairs in the acute surgical group compared to the chronic group (60.6% vs. 24.2%, P=0.003). After excluding complex tears, medial meniscus repair rates were no longer performed more frequently in patients undergoing acute ACL-R (59.4% vs. 33.3%, P=0.054).

CONCLUSIONS

Data from this prospective cohort suggest that with increasing time from ACL injury to ACL-R, medial meniscus pathology increases, with a lower likelihood of meniscal repair in all patients undergoing ACL-R. However, this finding is no longer statistically significant when considering only patients undergoing primary ACL-R. Age appears to play an important role in whether concomitant pathology develops following ACL rupture. Given these findings, early intervention may increase the ability to repair medial meniscus tears in the setting of ACL-R, but this conclusion is less supported in primary ACL-R.Level of Evidence: II.

Impact of Clinical Practice Guidelines on Use of Intra-Articular Hyaluronic Acid and Corticosteroid Injections for Knee Osteoarthritis

BACKGROUND

The efficacy of corticosteroid and hyaluronic acid injections for knee osteoarthritis has been questioned. The purpose of this study was to determine the impact of the American Academy of Orthopaedic Surgeons (AAOS) clinical practice guidelines on the use of these injections in the United States and determine if utilization differed by provider specialty.

METHODS

Patients with knee osteoarthritis were identified within the Humana database from 2007 to 2015, and the percentage of patients receiving a knee injection relative to the number of patients having an encounter for knee osteoarthritis was calculated and was trended for the study period. The impact of each edition of the AAOS clinical practice guidelines on injection use was evaluated with segmented regression analysis. Injection trends were also analyzed relative to the specialty of the provider performing the injection.

RESULTS

Of 1,065,175 patients with knee osteoarthritis, 405,101 (38.0%) received a corticosteroid injection and 137,005 (12.9%) received a hyaluronic acid injection. The rate of increase in hyaluronic acid use, per 100 patients with knee osteoarthritis, decreased from 0.15 to 0.07 injection per quarter year (p = 0.02) after the first clinical practice guideline, and the increase changed to a decrease at a rate of -0.12 injection per quarter (p < 0.001) after the second clinical practice guideline. After the first clinical practice guideline, the rate of increase in utilization of corticosteroids, per 100 patients with knee osteoarthritis, significantly lessened to 0.12 injection per quarter (p < 0.001), and after the second clinical practice guideline, corticosteroid injection use plateaued (p = 0.72). The trend in use of hyaluronic acid injections by orthopaedic surgeons and pain specialists decreased with time following the second-edition clinical practice guideline but did not change for primary care physicians or nonoperative musculoskeletal providers.

CONCLUSIONS

Subtle but significant changes in hyaluronic acid and corticosteroid injections occurred following the publication of both clinical practice guidelines. Although the clinical practice guidelines did impact injection use, given the high costs of these injections and their questionable clinical efficacy, further interventions beyond publishing clinical practice guidelines are needed to encourage higher-value care for patients with knee osteoarthritis.

Ganglion Cyst as a Rare Complication of Hip Arthroscopy Resolved With THA: A Case Report

BACKGROUND

A rare complication of hip arthroscopy is the development of a ganglion cyst. These cysts can affect structures surrounding the hip joint. In some cases, the femoral artery may be involved, leading to claudication or a pulsatile mass that can resemble an aneurysm.

CASE DESCRIPTION

We present the case of a 62 year-old male who complains of 3 months of right hip pain. Workup reveals a degenerative labrum with cam impingement. After a discussion of various treatment options, the patient elected for arthroscopy to correct the impingement. An anterior capsulotomy was created to establish access to the joint. Cam decompression was indicated to address the impingement. The patient developed a recurring ganglion cyst following the procedure that was not permanently prevented with cyst aspiration. Total hip arthroplasty with ganglion cyst decompression resolved the ganglion cyst and resolved the hip pain.

CONCLUSIONS

This is the first case report that describes the development of a ganglion cyst following hip arthroscopy. Arthroplasty and ganglion cyst decompression in the presence of degenerative joint disease presents a viable treatment option for these cysts. Additionally, this case suggests interportal capsulotomy closure may prevent ganglion cyst development and should be considered when performing hip arthroscopy.

Are We Still Prescribing Opioids for Osteoarthritis?

BACKGROUND

The United States is in the midst of an opioid epidemic. These medications continue to be used to manage pain associated with osteoarthritis, despite mounting evidence questioning the benefits. The rate at which opioids are prescribed for osteoarthritis is largely unknown. We sought to identify rates of opioid prescriptions for osteoarthritis and identify factors associated with higher rates of prescribing.

METHODS

We queried the Humana, Inc. administrative claims database from 2007 to 2014. Patients with osteoarthritis were identified using International Classification of Diseases 9th Revision codes and classified as having hip, knee, or any joint osteoarthritis. Claims data were reviewed to identify opioid prescriptions associated with a diagnosis of osteoarthritis. Rates of prescribing were trended over time and stratified by sex, age, and geographic region.

RESULTS

From 2007 to 2014, 17.0% of patients with any joint osteoarthritis, 13.4% of patients with hip osteoarthritis, and 15.9% with knee osteoarthritis were prescribed an opioid for their condition. Yearly rates of prescription were fairly stable over this period. Patients in the South had the highest odds of opioid prescription, while those in the Northeast had the lowest. Patients ≤49 years old were more likely to receive a prescription than those ≥50 years old.

CONCLUSION

This study provides important epidemiologic data about the use of opioids for osteoarthritis. Despite increasing evidence calling proposed benefits into question and increasing awareness of risks of opioids, prescribing rates remained stable between 2007 and 2014. This provides important baseline data as we work to combat excessive and inappropriate opioid use within the United States.

Are Trends in Total Hip Arthroplasty Bearing Surface Continuing to Change? 2007-2015 Usage in a Large Database Cohort

BACKGROUND

Bearing surface issues related to trunnionosis or metal-on-metal (MoM) articulations have likely impacted recent trends in bearing surface choice. The purpose of this study is to evaluate trends in total hip arthroplasty (THA) bearing surface use, including 2015 data, with respect to the date of operation and patient demographics.

METHODS

The Humana dataset was reviewed from 2007 through 2015 to analyze bearing surface usage in primary THA. Four bearing surface types were identified by International Classification of Disease, 10th Revision codes and trended throughout the years: metal-on-polyethylene (MoP), ceramic-on-ceramic (CoC), ceramic-on-polyethylene (CoP), and MoM. Prevalence was analyzed as a function of age and sex.

RESULTS

Of the 28,504 primary THA procedures, the most commonly used bearing was MoP (46.1%), followed by CoP (33.2%), MoM (17.1%), and ceramic-on-ceramic (3.6%). The use of CoP bearings significantly increased from 6.4% in 2007 to 52.0% in 2015, while MoM bearings decreased during this period. MoP bearings decreased over 2012-2015 (P < .001). CoP usage decreased with age, while MoP bearings increased with a transition occurring at 65-69 years of age. Women were more likely to receive MoP bearings (odds ratio [OR] 1.2), while men were more likely to receive MoM and CoP bearings (OR 1.1). Multivariate logistic regression showed age to be an independent predictor of bearing surface choice with patients 65 and older more likely to receive MoP bearings (OR 3.2).

CONCLUSION

Bearing surface choice in primary THA has changed tremendously from 2007 to 2015. MoM bearing use has decreased as a result of adverse effects. Age continues to remain a significant factor in bearing surface choice.

A new glucocerebrosidase-deficient neuronal cell model provides a tool to probe pathophysiology and therapeutics for Gaucher disease

Glucocerebrosidase is a lysosomal hydrolase involved in the breakdown of glucosylceramide. Gaucher disease, a recessive lysosomal storage disorder, is caused by mutations in the gene GBA1. Dysfunctional glucocerebrosidase leads to accumulation of glucosylceramide and glycosylsphingosine in various cell types and organs. Mutations in GBA1 are also a common genetic risk factor for Parkinson disease and related synucleinopathies. In recent years, research on the pathophysiology of Gaucher disease, the molecular link between Gaucher and Parkinson disease, and novel therapeutics, have accelerated the need for relevant cell models with GBA1 mutations. Although induced pluripotent stem cells, primary rodent neurons, and transfected neuroblastoma cell lines have been used to study the effect of glucocerebrosidase deficiency on neuronal function, these models have limitations because of challenges in culturing and propagating the cells, low yield, and the introduction of exogenous mutant GBA1. To address some of these difficulties, we established a high yield, easy-to-culture mouse neuronal cell model with nearly complete glucocerebrosidase deficiency representative of Gaucher disease. We successfully immortalized cortical neurons from embryonic null allele gba^−/− mice and the control littermate (gba^+/+) by infecting differentiated primary cortical neurons in culture with an EF1α-SV40T lentivirus. Immortalized gba^−/− neurons lack glucocerebrosidase protein and enzyme activity, and exhibit a dramatic increase in glucosylceramide and glucosylsphingosine accumulation, enlarged lysosomes, and an impaired ATP-dependent calcium-influx response; these phenotypical characteristics were absent in gba^+/+ neurons. This null allele gba^−/− mouse neuronal model provides a much-needed tool to study the pathophysiology of Gaucher disease and to evaluate new therapies.

Summary: This work describes the generation of a novel immortalized glucocerebrosidase-deficient neuronal cell model with utility for pathophysiology research and therapeutic development in Gaucher disease.

Interobserver variability in analysis of asbestos fibres and asbestos bodies in human lung tissue

Two different methods of quantifying asbestos fibre burden were assessed and the counts obtained were compared with semi-quantitative asbestos body counts in corresponding tissue sections. Comparison of the two methods found significantly different asbestos fibre counts between specimens. Each technique showed wide limits of agreement for reproducibility and interobserver variability as assessed by Bland-Altman plots, such that a repeated count could not necessarily be expected to lie within the same exposure category. Asbestos body counts in tissue sections were reproducible with good correlation between observers. Asbestos body and asbestos fibre counts showed correlation in some samples but not others. Counting of asbestos bodies is a valuable screening technique as the finding of asbestos bodies is accepted as a marker of significant asbestos exposure. When no asbestos bodies are identified asbestos fibres estimations may be useful in proving asbestos exposure. Different techniques are not interchangeable and each laboratory should establish a background range from unexposed individuals.

Observer variability in the Goseki grouping of gastric adenocarcinoma in resection and biopsy specimens

AIMS

The Goseki grouping of gastric adenocarcinoma has been suggested as a possible prognostic factor. In those centres where it is used, it may be valuable to assess the Goseki grouping of a tumour on the initial diagnostic biopsy as well as on the resection specimen since it may in theory influence management. We examined the robustness of Goseki grouping of gastric adenocarcinoma in representative sections from resection and biopsy specimens in order to assess the consistency of agreement among a group of pathologists.

METHODS

A single representative block from 100 gastric resection specimens was studied using a haematoxylin and eosin and mucin (alcian blue/periodic acid-Schiff) stain. These were circulated in batches to members of a group of 12 pathologists who each completed a simple proforma confirming the presence of carcinoma and assigning a Goseki group. In a second circulation the diagnostic biopsy specimen taken prior to resection was examined in the same way. This allowed comparison of the Goseki group of the biopsy and resection specimens.

RESULTS

In both studies kappa statistics showed good agreement on tubular differentiation of the carcinoma, but only moderate agreement for the intracellular mucin production, resulting in moderate agreement for the final Goseki group. Correlation between the Goseki group assigned on the biopsy and resected specimens was seen in 62% of the cases. However, the reproducibility was low (kappa 0.375).

CONCLUSIONS

The Goseki grouping of resected gastric adenocarcinoma is reproducible and can be used in prognostication. Goseki grouping of biopsy specimens is of limited value in predicting the Goseki group assigned to the resected carcinoma.

Malignant mesothelioma: a comparison of biopsy and postmortem material by light microscopy and immunohistochemistry

AIMS

The diagnosis of malignant mesothelioma in pleural biopsies can be difficult. Survival is short and consequently many of these cases are submitted to necropsy to assist with medicolegal claims. This study compares the histological appearances and immunohistochemical profile of nine biopsy specimens with corresponding postmortem specimens.

METHODS

Archival, formalin fixed, paraffin wax embedded material was obtained from nine biopsy and corresponding postmortem cases of malignant mesothelioma. The specimens were examined by light microscopy and stained with an immunohistochemical panel of 12 commercially available antibodies including CAM5.2, HBME-1, and Ber-EP4, and antibodies to thrombomodulin, calretinin, CD44H, WT-1, carcinoembryonic antigen, Leu-M1, epithelial membrane antigen and p53.

RESULTS

There was greater variation in the range of histological appearances of mesotheliomas in postmortem specimens compared with biopsy specimens. There was also variability in the immunohistochemical staining pattern for certain antibodies including HBME-1, and Ber-EP4 and antibodies to calretinin, CD44H, WT-1, and p53.

CONCLUSIONS

All available information should be taken into account in the histological diagnosis of malignant mesothelioma. Interpretation of the immunohistochemical profile should be regarded with some caution when only postmortem material is available. When reporting a postmortem case of suspected mesothelioma, the pathologist should seek to review all available biopsy material in conjunction with the necropsy.

Immunohistochemical analysis still has a limited role in the diagnosis of malignant mesothelioma. A study of thirteen antibodies

To identify the most accurate and useful panel to diagnose mesothelioma, we immunostained sections from 112 mesotheliomas, 18 adenocarcinomas, and 11 reactive pleural specimens with 13 antibodies. Positive results for mesotheliomas, adenocarcinomas, and reactive pleura, respectively, were CAM5.2, 111, 18, and 11; vimentin, 30, 3, and 3; HBME-1, 75, 10, and 8; thrombomodulin, 31, 2, and 2; calretinin, 43, 6, and 11; and CD44H, 68, 10, and 4. Positive results for adenocarcinoma markers in mesotheliomas and adenocarcinomas, respectively, were carcinoembryonic antigen, 1 and 15; LeuM1, 7 and 9; and Ber-EP4, 5 and 12. All reactive pleura were negative. Positive results for markers to help distinguish mesothelioma from reactive pleura in mesotheliomas, adenocarcinomas, and reactive pleura, respectively, were epithelial membrane antigen, 76, 17, and 6; p53, 78, 16, and 9; P-170 glycoprotein, 37, 4, and 2; and platelet-derived growth factor receptor beta, 31, 1, and 2. The differential diagnosis of mesothelioma from adenocarcinoma is based on negative markers. Individual mesothelial markers are of low sensitivity and specificity for mesothelioma. However, diagnostic accuracy is improved by the use of antibody panels. To date there are no antibodies that help distinguish mesothelioma from reactive pleura.

Consistency of histopathological reporting of laryngeal dysplasia. The Scottish Pathology Consistency Group

AIMS

Clinical management of premalignant and malignant lesions of the larynx is dependent on histopathological evaluation. The Scottish Pathology Consistency Group assessed interobserver variation in the evaluation of laryngeal dysplasia.

METHODS AND RESULTS

One hundred laryngeal biopsies ranging from normal to invasive carcinoma were assessed. The overall Kappa result of 0.32 was disappointing. However, agreement on those categories which dictate significantly different management was more favourable. The Kappa figure for mild dysplasia versus severe dysplasia/CIS was 0.7, the Kappa figure for mild dysplasia versus severe dysplasia/CIS and invasive carcinoma was 0.77. The Kappa figure for mild and moderate dysplasia versus severe dysplasia/ CIS and invasive carcinoma was 0.57. An attempt to use a two grade system gave a Kappa figure of 0.52.

CONCLUSIONS

Our group had a satisfactory agreement on the distinction of mild from severe dysplasia and on microinvasive carcinoma without any discussion as to histopathological criteria to be used. Clinical management--review endoscopy, repeat cord stripping, radiotherapy and laryngectomy--is in general dependent on histological assessment. Thus the agreement on categories which underpin clinical management is reassuring. However, assessment of moderate dysplasia remains problematic. An attempt to utilize a two grade system--low grade from high grade dysplasia/CIS--may have merit. The implications of the terminology used must be agreed among pathologists and clinicians working closely within clinicopathological cancer groups.

Coactivation of the antagonist muscle does not covary with steadiness in old adults

The purpose of the study was to determine the association between steadiness and activation of the agonist and antagonist muscles during isometric and anisometric contractions. Young (n = 14) and old (n = 15) adults used the first dorsal interosseus muscle to perform constant-force and constant-load tasks (2.5, 5, 20, 50, and 75% maximum) with the left index finger. Steadiness was quantified as the coefficient of variation of force and the SD of acceleration normalized to the load lifted. The old adults were less steady at most target forces with isometric contractions (2.5, 5, and 50%) and with most loads during the anisometric contractions (2.5, 5, and 20%). Furthermore, the old adults were less steady when performing lengthening contractions (up to 50%) compared with shortening contractions, whereas there was no difference for young adults. The reduced steadiness exhibited by the old adults during these tasks was not associated with differences in the average level of agonist muscle electromyogram or with coactivation of the antagonist muscle.

Apoptosis in cervical squamous carcinoma: predictive value for survival following radiotherapy

BACKGROUND

Apoptosis, or programmed cell death, can be induced by radiotherapy. The extent of apoptosis in a tumour before treatment may have important implications for response to radiotherapy and long term survival.

AIM

To examine the extent of apoptosis in tumour tissue from patients with squamous carcinoma of the cervix before radiotherapy, and to correlate this with response to treatment and prognosis.

METHODS

The percentage of apoptotic cells was assessed in 146 carcinomas of the cervix from patients scheduled to receive radiotherapy. The CAS 200 static image analysis system was used to count the number of tumour nuclei per high power field, while the numbers of apoptotic cells in the same field were visualised simultaneously on the image analyser and recorded manually.

RESULTS

The median apoptotic level was 0.73%. Patients were divided into two groups around the median. There was no statistically significant difference in outcome between the two groups as determined by long term survival following radiotherapy.

CONCLUSIONS

The CAS 200 static image analyser system can be used to assist in the rapid semiautomated assessment of apoptosis in conventionally prepared tissue. The results suggest that the apoptotic state of a tumour before treatment is of no value in predicting response to radiotherapy and subsequent prognosis. Tumour stage, size, and BrdU labelling index, as a measure of proliferation rate, remain the most important prognostic factors in terms of predicting local tumour control.

Observer variability in the histopathological reporting of needle biopsy specimens of the prostate

The Scottish Pathology Consistency Group has in previous studies examined the consistency of histopathological reporting of biopsies from the cervix, bladder, bronchus, and rectum. In the current study, consisting of 100 needle biopsy specimens of the prostate, a single hematoxylin-eosin (H&E) slide from each case was circulated in batches of 10 to the 12 pathologists, who filled in a simple proforma. This had two sections: a diagnostic category (benign; suspicious or malignant) along with a standard Gleason score for those regarded as malignant. The majority diagnosis of the 100 cases was benign, 53; suspicious, 1; and malignant, 46. The Kappa value for benign cases versus others was 0.86 and for malignant cases versus others was 0.91. Analysis of the data on Gleason scores showed a value of 0.54 when cases were divided into two categories (2 to 6 v 7 to 10) and 0.41 when three categories were used (2 to 4; 5 to 6; 7 to 10). Although not initially part of the design of the study, the majority diagnosis was compared with the original reported diagnosis. In a small subset, examination of further levels, basal cell antibody staining, along with further clinical information, was obtained. With this added information, it appears that there were probably 52 benign and 48 malignant cases. Of the 48 malignant cases, the group majority diagnosis was malignant, 46; suspicious, 1; and benign, 1. The original reported diagnosis was 56 benign, 1 suspicious, and 43 malignant. The group therefore appeared to perform better than the original reporting pathologists. When compared with the results of our previous studies, this study has shown that the diagnosis of carcinoma of the prostate on a needle biopsy is robust.

Effusion cytology of hepatocellular carcinoma with in situ hybridisation for human albumin

While the cytological features of hepatocellular carcinoma on fine needle aspiration cytology are well described, cases of hepatocellular carcinoma with malignant cells in ascitic fluid and their characteristics are not. A patient is described with cirrhosis resulting from chronic hepatitis B virus infection, ascites, and hepatocellular carcinoma diagnosed by effusion cytology. The malignant cells in the effusion were shown to be positive for alpha fetoprotein using immunocytochemistry, and for human albumin using in situ hybridisation, confirming the diagnosis of hepatocellular carcinoma. Further investigations in a terminally ill patient were thus avoided.

Adenocarcinoma of the anal glands

Adenocarcinoma of the anal glands is very rare but it is an important lesion to recognise as with early diagnosis, it has an excellent prognosis. Because it involves the submucosa widely and penetrates the mucosa late, it can be mistaken for metastatic gastrointestinal carcinoma, or tumour arising in sinuses and fistulae. Two cases, in a 44 year old man and a 73 year old woman, which illustrate the typical features are reported, in one of which the diagnosis was missed originally. In situ neoplastic change of the associated anal glands and secretion of mucin lacking O-acetyl groups are useful pointers.

Observer variability in histopathological reporting of non-small cell lung carcinoma on bronchial biopsy specimens

AIMS

To evaluate the ability of histopathologists to sub-classify non-small cell lung carcinomas on bronchial biopsy material using the current World Health Organisation (WHO) classification.

METHODS

Twelve histopathologists each reviewed 100 randomly selected bronchial biopsy specimens which had originally been reported as showing non-small cell lung carcinoma. For each case, two sections were circulated, one stained by haematoxylin and eosin and the other by a standard method for mucin (alcian blue/periodic acid Schiff). The participants were allowed to indicate their degree of confidence in their classification of each case. A standard proforma was completed and the results were analysed using kappa statistics.

RESULTS

Where the participants were confident in their classification, they were actually quite good at sub-classifying the non-small cell carcinoma sections (kappa = 0.71, standard error = 0.058). Overall, however, the results were only fair (kappa = 0.39, standard error = 0.034).

CONCLUSIONS

The majority of non-small cell lung carcinomas can be correctly categorised on adequate bronchial biopsy material. Where a confident diagnosis was made, both squamous carcinoma (kappa = 0.73) and adenocarcinoma (kappa = 0.83) were well recognised.

Observer variability in histopathological reporting of malignant bronchial biopsy specimens

AIMS

To evaluate the ability of histopathologists to classify lung carcinomas on bronchial biopsy material using the current World Health Organisation (WHO) classification.

METHODS

Eleven histopathologists each reviewed 100 randomly selected bronchial biopsy specimens which had originally been reported as showing lung carcinoma. A single haematoxylin and eosin stained section from each case was circulated and a standard proforma completed. These were analysed using kappa statistics.

RESULTS

The histopathologists were excellent at distinguishing between small cell and non-small-cell carcinoma kappa = 0.86), but not so good at subclassifying the non-small cell carcinoma group kappa = 0.25).

CONCLUSIONS

The clinically important distinction between small cell and non-small cell carcinoma of the lung is reliably made by competent histopathologists even on limited material.

Observer variability in the histopathological reporting of abnormal rectal biopsy specimens

AIMS

To study the consistency of reporting of abnormal rectal biopsy specimens, especially in the differentiation of inflammatory bowel disease from other causes of abnormality.

METHODS

Sixty rectal biopsy specimens were identified from patients presenting with bloody diarrhoea. These were then circulated to the 11 consultant pathologists in the study who filled in a proforma with a list of 12 diagnostic categories and 22 features.

RESULTS

Forty one of the 60 cases were examples of inflammatory bowel disease. In 33 of these cases nine or more pathologists had made the diagnosis. Further categorisation into ulcerative colitis and Crohn's disease showed better recognition of ulcerative colitis. In the 19 cases of non-inflammatory bowel disease recognition of pseudomembranous colitis and solitary rectal ulcer syndrome was good, but the results were poorer in the case of infective colitis.

CONCLUSION

The findings suggest that a group of consultant pathologists can differentiate between inflammatory bowel disease and other causes of an abnormal rectal biopsy specimen and can also recognise pseudomembranous colitis and solitary rectal ulcer syndrome satisfactorily.