bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quality Measure Public Reporting Is Associated with Improved Outcomes Following Hip and Knee Replacement
Authors: Bozic Kevin , Yu Huihui , Zywiel Michael G. , Li Li , Lin Zhenqiu , Simoes Jaymie L. , Dorsey Sheares Karen , Grady Jacqueline , Bernheim Susannah M. , Suter Lisa G. 
Published: August 2020

Background:
Given the inclusion of orthopaedic quality measures in the Centers for Medicare & Medicaid Services national hospital payment programs, the present study sought to assess whether the public reporting of total hip arthroplasty (THA) and total knee arthroplasty (TKA) risk-standardized readmission rates (RSRRs) and complication rates (RSCRs) was temporally associated with a decrease in the rates of these outcomes among Medicare beneficiaries.

Methods:
Annual trends in national observed and hospital-level RSRRs and RSCRs were evaluated for patients who underwent hospital-based inpatient hip and/or knee replacement procedures from fiscal year 2010 to fiscal year 2016. Hospital-level rates were calculated with use of the same measures and methodology that were utilized in public reporting. Annual trends in the distribution of hospital-level outcomes were then examined with use of density plots.

Results:
Complication and readmission rates and variation declined steadily from fiscal year 2010 to fiscal year 2016. Reductions of 33% and 25% were noted in hospital-level RSCRs and RSRRs, respectively. The interquartile range decreased by 18% (relative reduction) for RSCRs and by 34% (relative reduction) for RSRRs. The frequency of risk variables in the complication and readmission models did not systematically change over time, suggesting no evidence of widespread bias or up-coding.

Conclusions:
This study showed that hospital-level complication and readmission rates following THA and TKA and the variation in hospital-level performance declined during a period coinciding with the start of public reporting and financial incentives associated with measurement. The consistently decreasing trend in rates of and variation in outcomes suggests steady improvements and greater consistency among hospitals in clinical outcomes for THA and TKA patients in the 2016 fiscal year compared with the 2010 fiscal year. The interactions between public reporting, payment, and hospital coding practices are complex and require further study.

Level of Evidence:
Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
Risk Factors for Revision of Polished Taper-Slip Cemented Stems for Periprosthetic Femoral Fracture After Primary Total Hip Replacement
Authors: Lamb J.N. , Jain S. , King S.W. , West R.M. , Pandit H.G. 
Published: August 2020

Background:
Total hip replacement (THR) with a cemented polished taper-slip (PTS) femoral stem has excellent long-term results but is associated with a higher postoperative periprosthetic femoral fracture (PFF) risk compared with composite beam stems. This study aimed to identify risk factors associated with PFF revision following THR with PTS stems.

Methods:
In a retrospective cohort study, 299,019 primary THRs using PTS stems from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man (NJR) were included, with a median follow-up of 5.2 years (interquartile range [IQR], 3.1 to 8.2 years). The adjusted hazard ratio (HR) of PFF revision was estimated for each variable using multivariable Cox survival regression analysis.

Results:
Of 299,019 THR cases, 1,055 underwent revision for PFF at a median time of 3.1 years (IQR, 1.0 to 6.1 years). The mean age (and standard deviation) was 72 ± 9.7 years, 64.3% (192,365 patients) were female, and 82.6% (247,126 patients) had an American Society of Anesthesiologists (ASA) class of 1 or 2. Variables associated with increased PFF were increasing age (HR, 1.02 per year), intraoperative fracture (HR, 2.57 [95% confidence interval (CI), 1.42 to 4.66]), ovaloid (HR, 1.96 [95% CI, 1.22 to 3.16]) and round cross-sectional shapes (HR, 9.58 [95% CI, 2.29 to 40.12]), increasing stem offset (HR, 1.07 per millimeter), increasing head size (HR, 1.04 per millimeter), THR performed from 2012 to 2016 (HR, 1.45 [95% CI, 1.18 to 1.78]), cobalt-chromium stem material (HR, 6.7 [95% CI, 3.0 to 15.4]), and cobalt-chromium stems with low-viscosity cement (HR, 22.88 [95% CI, 9.90 to 52.85]). Variables associated with a decreased risk of PFF revision were female sex (HR, 0.52 [95% CI, 0.45 to 0.59]), increasing stem length (HR, 0.97 per millimeter), and a ceramic-on-polyethylene bearing (HR, 0.55 [95% CI, 0.36 to 0.85]).

Conclusions:
Increased risk of PFF revision was associated with PTS stems that are short, have high offset, are used with large femoral heads, are made of cobalt-chromium, or have ovaloid or round cross-sectional shapes. Large increases in PFF risk were associated with cobalt-chromium stems used with low-viscosity cement. Further study is required to confirm causation.

Level of Evidence:
Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
The Implications of Aging Population Demographics on the Delivery of Primary Total Joint Arthroplasty in a Bundled Payment System
Authors: Petersen William P. , Teo Greg Michael , Friedlander Scott , Schwarzkopf Ran , Long William J. 
Published: August 2020

Background:
The Centers for Medicare & Medicaid Services (CMS)’s Bundled Payments for Care Improvement (BPCI) program provides a set payment for the provision of primary total joint arthroplasty (TJA) care regardless of age and risk factors. Published literature indicates that the cost of care per episode of TJA increases with age. We examined the implication of this relationship and the effect of projected changes of age demographics on our center’s BPCI experience.

Methods:
A retrospective review of prospectively collected data on 1,662 Medicare BPCI patients undergoing primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) from 2013 to 2016 at a single orthopaedic institution was performed. The relationship between age and cost of care was first determined in our analysis of our BPCI experience. We then performed a cost analysis by age group with respect to our institution’s profit or loss per episode of care. A forecast for shifting age demographics in our region, modeled by the U.S. Census Bureau’s Federal-State Cooperative for Population Estimates (FSCPE) and Projections (FSCPP), was used to evaluate the financial implications for our BPCI program.

Results:
Our institution sustains a significant loss of $1,934 (p < 0.001) per case for patients 85 to 99 years of age, which is offset by profits associated with treating patients in younger age groups. This age group (85 to 99 years of age) will double by the year 2040 in our region, whereas the youngest age group (65 to 69 years of age) is projected to marginally increase by 12%. The average cost of care per primary TJA will rise because of the predicted shifting age demographics, compounded by an estimated 3% inflation rate. Utilizing the current BPCI reimbursement rate, we project an inflection point of declining profits after the year 2030 with the given projections for our regional population.

Conclusions:
The regional population served by our institution is aging. This shift will lead to an increased cost of care and diminishing profits for TJA after 2030. The CMS’s BPCI initiative and novel alternative payment models (APMs) should consider age as a modifier for reimbursement to incentivize care for the vulnerable and older age groups.

Clinical Relevance:
The findings of the present study are clinically relevant for decision-making regarding the allocation of resources in the setting of an aging population.
The 3 Sagittal Morphotypes That Define the Normal Cervical Spine
Authors: Virk Sohrab , Lafage Renaud , Elysee Jonathan , Louie Philip , Kim Han Jo , Albert Todd , Lenke Lawrence G. , Schwab Frank , Lafage Virginie 
Published: August 2020

Background:
Cervical alignment is vital for maintaining horizontal gaze and sagittal balance. The aims of this study were to summarize previously published descriptions of normative cervical alignment and to analyze a cohort of asymptomatic volunteers in order to identify natural clusters of normal radiographic parameters.

Methods:
We performed a systematic review of the literature on radiographic measurements of asymptomatic volunteers through a search of MEDLINE and ScienceDirect databases. We then performed an analysis of demographic and radiographic parameters of volunteers without back or neck complaints. Only subjects with a chin-brow vertical angle (CBVA) within previously published normal limits were retained for analysis. A 2-step cluster analysis was used to find natural groups of cervical alignment. Differences among groups were investigated with a post hoc analysis of variance (ANOVA).

Results:
We included 37 articles in our analysis. There was a broad spectrum of both C2-C7 lordosis-kyphosis and T1 slope across ages and sexes. Of the 119 asymptomatic volunteers who were available for analysis, 84 (with a mean age [and standard deviation] of 49.0 ± 17.1 years) had a CBVA ranging from −4.7° to 17.7°. The cluster analysis identified 3 alignment groups based on cervical lordosis-kyphosis and T1 slope (silhouette measure of cohesion, >0.6). Twenty-seven volunteers (32.1%) were identified as the “kyphotic curve cohort” (KCC) (mean C2-C7 Cobb angle, −8.6° ± 7.3°; mean T1 slope, 17.4° ± 6.6°), 43 volunteers (51.2%) were identified as the “medium lordosis cohort” (MLC) (mean C2-C7 Cobb angle, 8.7° ± 7.2°; mean T1 slope, 26.6° ± 4.0°), and 14 volunteers (16.7%) were identified as the “large lordosis cohort” (LLC) (mean C2-C7 Cobb angle, 21.2° ± 7.2°, mean T1 slope, 39.5° ± 6.4°) (p < 0.001 for both). Moving from KCC to LLC, there was a significant decrease in C0-C2 lordosis (p = 0.016). Examination of the cervical vertebral orientation demonstrated that C4 had a constant orientation relative to the horizontal (p = 0.665). Correlation analysis between C2-C7 and vertebral orientations again demonstrated that C4 orientation was independent of C2-C7 alignment.

Conclusions:
We have identified 3 morphotypes of the cervical spine based on C2-C7 alignment and T1 slope. These findings demonstrate the broad definition of normal cervical alignment and the range of cervical lordosis-kyphosis that is acceptable.
Microstructural and Mechanical Properties of Grafts Commonly Used for Cruciate Ligament Reconstruction
Authors: Castile Ryan M. , Jenkins Matthew J. , Lake Spencer P. , Brophy Robert H. 
Published: August 2020

Background:
Injuries to the anterior cruciate ligament and posterior cruciate ligament are common, and often are treated with reconstruction. Limited quantitative data are available describing material properties of grafts used for reconstructions such as the bone-patellar tendon-bone (BPTB), hamstring tendon (HS), and quadriceps tendon (QT). The purpose of this study was to quantify and compare microstructural and mechanical properties of BPTB, HS, and QT grafts.

Methods:
Forty specimens (13 BPTB, 13 HS, and 14 QT grafts) from 24 donors were used. Specimens were subjected to preconditioning, stress relaxation, and ramp to failure. Mechanical parameters were calculated for each sample, and polarization imaging was used to evaluate the direction and strength of collagen fiber alignment during testing.

Results:
QT had the largest modulus values, and HS had the smallest. BPTB exhibited the least disperse collagen organization, while HS were the least strongly aligned. Microstructural properties showed more strongly aligned collagen with increasing load for all grafts. All tissues showed stress relaxation and subtle microstructural changes during the hold period.

Conclusions:
The mechanical and microstructural properties differed significantly among BPTB, HS, and QT grafts. QT exhibited the largest moduli and greatest strength of collagen alignment, while HS had the smallest moduli and least strongly aligned collagen.

Clinical Relevance:
This study identified mechanical and microstructural differences among common grafts and between these grafts and the cruciate ligaments they replace. Further research is needed to properly interpret the clinical relevance of these differences.
An Update on Cementless Femoral Fixation in Total Hip Arthroplasty
Authors: Kheir Michael M. , Drayer Nicholas J. , Chen Antonia F. 
Published: August 2020

➤ Cementless stems can be categorized using the updated classification system.➤ Short stems were designed as an alternative to conventional stems with the advantage of bone preservation, and they have grown in popularity with promising results; however, long-term outcomes are lacking.➤ Hydroxyapatite coating appears to have no advantage with respect to stem loosening.➤ The literature has shown no difference in revision rates between modular and nonmodular stems; however, with the advantages of equalizing limb lengths and offset come the drawbacks of corrosion and junctional fatigue failure of modular implants.➤ There is increasing use of cementless stems, including in octogenarians, with promising outcomes compared with cemented stems; however, there is a higher risk of periprosthetic fractures with cementless fixation, particularly in elderly female patients.
Blood Management for Elective Orthopaedic Surgery
Authors: Palmer Antony J.R. , Gagné Sylvain , Fergusson Dean A. , Murphy Michael F. , Grammatopoulos George 
Published: August 2020

➤ Strategies to conserve blood and reduce exposure to allogeneic blood improve outcomes after orthopaedic surgery.➤ A multidisciplinary team approach, including surgeons, anesthesiologists, hematologists, and other medical specialties, is required to deliver optimal blood management.➤ Key steps are to optimize preoperative hemoglobin levels, administer antifibrinolytics, use cell salvage for procedures with high blood loss, and adhere to restrictive transfusion thresholds.
Acetabular Labral Reconstruction with Iliotibial Band Autograft
Authors: Philippon Marc J. , Arner Justin W. , Crawford Matthew D. , Bolia Ioanna K. , Briggs Karen K. 
Published: August 2020

Background:
Labral reconstruction has been shown to result in improved patient-reported outcomes (PROs) at mid-term follow-up in patients with a deficient labrum. The purpose of this study was to determine survivorship and PROs at a minimum 10-year follow-up.

Methods:
A retrospective evaluation of a prospectively collected single-surgeon database included 91 hips (89 patients) that underwent arthroscopic labral reconstruction with iliotibial band autograft between 2006 and 2008. The primary PRO was the Hip Outcome Score (HOS)-activities of daily living (ADL). The modified Harris hip score (mHHS), HOS-sports, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and patient satisfaction (on a scale of 1 to 10) were also collected at a 10-year minimum follow-up. Survivorship analysis curves were evaluated.

Results:
Eighty-two hips were evaluated at a 10-year minimum follow-up. Overall survivorship, with revision hip arthroscopy or total hip arthroplasty (THA) as the end point, was 70% at 5 years and 61% at 10 years, and the mean survival time was 9 years (95% confidence interval = 7.6 to 10 years). For the patients who did not undergo subsequent surgery, on average the mHHS increased from 60 preoperatively to 82 at the 10-year follow-up (p = 0.001), the HOS-ADL improved from 69 to 90 (p = 0.004), the HOS-sports improved from 43 to 76 (p = 0.001), and the median patient satisfaction was 10 of 10. Eighty percent of the patients achieved the minimal clinically important difference (MCID) in the HOS-ADL, and 87% obtained a patient acceptable symptom state (PASS).

Conclusions:
Following arthroscopic labral reconstruction with iliotibial band autograft, 9% of the hips underwent revision arthroscopy and 27% underwent THA. At 10 years, the survival rate, with revision hip arthroscopy or THA as the end point, was 61%; however, for those with >2 mm of joint space, the current indication for labral reconstruction, the 10-year survival rate was 90%. Excellent PROs and patient satisfaction were reported by those who did not require revision or THA. With appropriate patient selection and prevention of postoperative adhesions, labral reconstruction results in excellent outcomes and high patient satisfaction that is sustained at a minimum 10-year follow-up.

Level of Evidence:
Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Hitting the Target: Natural History of the Hip Based on Achieving an Acetabular Safe Zone Following Periacetabular Osteotomy
Authors: Wyles Cody C. , Vargas Juan S. , Heidenreich Mark J. , Mara Kristin C. , Peters Christopher L. , Clohisy John C. , Trousdale Robert T. , Sierra Rafael J. 
Published: August 2020

Background:
Periacetabular osteotomy (PAO) remains the gold-standard treatment for acetabular dysplasia in skeletally mature patients with preserved cartilage. The purpose of this multicenter cohort study was to delineate the long-term radiographic natural history of the dysplastic hip following PAO based on the final position of the acetabular fragment.

Methods:
We evaluated patients who underwent PAO performed by 4 hip preservation surgeons to treat acetabular dysplasia with or without concomitant retroversion from 1996 to 2012 at 3 academic institutions. There were 288 patients with a mean clinical and radiographic follow-up of 9 years (range, 5 to 21 years). Postoperative radiographs made at the first clinical visit were used to determine if the acetabular fragment fell into a safe zone according to the absence of retroversion, a lateral center-edge angle (LCEA) of 25° to 40°, an anterior center-edge angle (ACEA) of 25° to 40°, and a Tönnis angle of 0° to 10°. Every available subsequent radiograph was assessed for degenerative changes by the Tönnis classification (grades 0 to 3). The time to progression was analyzed using Cox proportional hazards regression and multistate modeling.

Results:
Only the absence of retroversion was independently associated with a decreased risk of progressing at least 1 Tönnis grade during follow-up: hazard ratio (HR), 0.60 (95% confidence interval [CI], 0.38 to 0.94; p = 0.025). Achieving the ACEA safe zone yielded the greatest time increase for remaining in Tönnis grade 0 or 1 (43 years for having an ACEA in the safe zone compared with 28 years for not having an ACEA in the safe zone), followed by the absence of retroversion (34 years for the absence of retroversion compared with 24 years for the presence of retroversion). However, attaining the Tönnis angle or LCEA safe zones did not delay progression. The achievement of additional safe zones generally increased the length of time that patients spent in Tönnis grade 0 or 1: 25 years for 0 safe zones, 36 years for 1 safe zone, 29 years for 2 safe zones, 37 years for 3 safe zones, and 44 years for 4 safe zones.

Conclusions:
This study demonstrates the importance of achieving appropriate acetabular reorientation to enhance the longevity of the native hip following PAO. Although the LCEA and the Tönnis angle are the most common metrics used to assess appropriate acetabular correction, this study shows that adequately addressing retroversion and the ACEA has a greater impact on improving the natural history.

Level of Evidence:
Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Hip Resurfacing Compared with 28-mm Metal-on-Metal Total Hip Replacement
Authors: Vendittoli Pascal-André , Shahin Maged , Rivière Charles , Roy Alain Guy , Barry Janie , Lavigne Martin 
Published: August 2020

Background:
Bone stock conservation, hip anatomy preservation, and greater stability are among the promoted advantages of hip resurfacing (HR). However, the disappointing failure of some implants nearly led to its abandonment. The aim of this study was to compare clinical scores and revision and complication rates after HR with those after total hip arthroplasty (THA).

Methods:
Two hundred and three hips were randomized to 28-mm metal-on-metal (MoM) THA (99 hips) or to HR (104 hips). Main outcome measures compared between groups were the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, the revision rate, and the complication rates. The radiographic findings were also assessed.

Results:
After a mean follow-up of 15 years (range, 14 to 16 years), 9 (4.4%) of the 203 patients were lost to follow-up and 15 (7.4%) had died. The Kaplan-Meier survivorship, with revision for any reason as the end point, was 89.2% (95% confidence interval [CI], 82.3% to 96.1%) for HR and 94.2% (95% CI, 89.3% to 99.1%) for THA (p = 0.292). The reasons for revision included infection (3 patients), recurrent dislocation (1 patient), and adverse reaction to metal debris (ARMD) (1 patient) in the THA group and ARMD (2 patients) and femoral head loosening (7 patients) in the HR group. With aseptic revision as the end point, the Kaplan-Meier survivorship was significantly higher in the THA group (97.4% versus 89.2%; p = 0.033). No dislocation occurred in the HR group compared with 4 in the THA group (p = 0.058). Both groups achieved a similar mean WOMAC score (10.7 in the HR group and 8.8 in the THA group; p = 0.749), Forgotten Joint Score (87.1 and 85.3, respectively; p = 0.410), University of California Los Angeles (UCLA) activity score (6.3 and 6.4, respectively; p = 0.189), and overall joint perception (p = 0.251).

Conclusions:
The specific HR and MoM 28-mm THA implants used in this study showed good long-term survival and function. The overall rates of complications and revisions were similar in both groups but were of different types. As it provides better femoral bone preservation and biomechanical reconstruction, HR may continue to have a role in selected patients when performed by experienced surgeons and using validated implants.

Level of Evidence:
Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.