Reliability of the Walch Classification for Characterization of Primary Glenohumeral Arthritis: A Systematic Review.

INTRODUCTION: The Walch classification has been widely accepted and further developed as a method to characterize glenohumeral arthritis. However, many studies have reported low and inconsistent measures of the reliability of the Walch classification. The purpose of this study was to review the literature on the reliability of the Walch classification and characterize how imaging modality and classification modifications affect reliability. METHODS: A systematic review of publications that included reliability of the Walch classification reported through intraobserver and interobserver kappa values was conducted. A search in January 2021 and repeated in July 2023 used the terms ["Imaging" OR "radiography" OR "CT" OR "MRI"] AND ["Walch classification"] AND ["Glenoid arthritis" OR "Shoulder arthritis"]. All clinical studies from database inception to July 2023 that evaluated the Walch or modified Walch classification's intraobserver and/or interobserver reliability were included. Cadaveric studies and studies that involved subjects with previous arthroplasty, shoulder débridement, glenoid reaming, interposition arthroplasty, and latarjet or bankart procedure were excluded. Articles were categorized by imaging modality and classification modification. RESULTS: Thirteen articles met all inclusion criteria. Three involved the evaluation of plain radiographs, 10 used CT, two used three-dimensional (3D) CT, and four used magnetic resonance imaging. Nine studies involved the original Walch classification system, five involved a simplified version, and four involved the modified Walch. Six studies examined the reliability of raters of varying experience levels with none reporting consistent differences based on experience. Overall intraobserver reliability of the Walch classifications ranged from 0.34 to 0.92, and interobserver reliability ranged from 0.132 to 0.703. No consistent trends were observed in the effect of the imaging modalities or classification modifications on reliability. DISCUSSION: The reliability of the Walch classification remains inconsistent, despite modification and imaging advances. Consideration of the limitations of the classification system is important when using it for treatment or prognostic purposes.

Funding bias in shoulder arthroplasty research.

BACKGROUND: Prior research has shown that industry funding can impact the outcomes reported in medical literature. Limited data exist on the degree of bias that industry funding may have on shoulder arthroplasty literature outside of the Journal of Shoulder and Elbow Surgery. The purpose of this study is to characterize the type and frequency of funding for recently published shoulder arthroplasty studies and the impact of industry funding on reported outcomes. We hypothesized that studies with industry funding are more likely to report positive outcomes than those without. MATERIALS AND METHODS: We performed a retrospective study searching all articles with the term "shoulder arthroplasty," "reverse shoulder arthroplasty," "anatomic total shoulder arthroplasty," or "total shoulder arthroplasty" on PubMed from the years January 2020 to December 2022. The primary outcome of studies was coded as either positive, negative, or neutral. A positive result was defined as one in which the null hypothesis was rejected. A negative result was defined as one in which the result did not favor the group in which the industry-funded implant was used. A neutral result was defined as one in which the null hypothesis was confirmed. Article funding type, subcategorized as National Institutes of Health funding or industry funding was recorded. Author disclosures were recorded to determine conflicts of interest. Statistical analysis was conducted using the χ2 test and Fisher exact test. RESULTS: A total of 750 articles reported on either conflict of interest or funding source and were included in the study. Of the total number of industry-funded studies, the majority were found to have a positive primary endpoint (58.1%, 104 of 179), as compared to a negative (7.8%, 14 of 179) or neutral endpoint (33.5%, 60 of 179) (P = .004). Overall, 363 articles reported an author conflict of interest, and the majority of these studies had positive primary endpoint (55.6%, 202 of 363) as compared to negative (9.1%, 33 of 363) or neutral endpoints (34.4%, 125 of 363) (P = .002). CONCLUSION: The results of this study suggest that there is a significant relationship between conflicts of interest and the primary outcome of shoulder arthroplasty studies, beyond the overall positive publication bias. Studies with industry funding and author conflicts of interest both report positive outcomes more frequently than negative outcomes. Shoulder surgeons should be aware of this potential bias when choosing to base clinical practice on published data.

Biomechanics of subscapularis V-shaped tenotomy compared to standard tenotomy.

BACKGROUND: Subscapularis function is critical after anatomic total shoulder arthroplasty (aTSA). Recently, however, a technique has been described that features a chevron or V-shaped subscapularis tendon cut (VT). This biomechanical study compared repair of the standard tenotomy (ST), made perpendicular to the subscapularis fibers, to repair of the novel VT using cyclic displacement, creep, construct stiffness, and load to failure. METHODS: This biomechanical study used 6 pairs of fresh frozen paired cadaveric shoulder specimens. One specimen per each pair underwent VT, the other ST. Subscapularis tenotomy was performed 1 cm from the insertion onto the lesser tuberosity. For VT, the apex of the V was 3 cm from the lesser tuberosity. After tenotomy, each humerus underwent humeral head arthroplasty. Eight figure-of-8 sutures were used to repair the tenotomy (Ethibond Excel; Ethicon, US LLC). Specimens were cyclically loaded from 2 to 100 N at 45 degrees abduction at a rate of 1 Hz for 3000 cycles. Cyclic displacement, creep, and stiffness and load to failure were measured. RESULTS: Cyclic displacement did not differ significantly between the ST and VT from 1 to 3000 cycles. The difference in displacement between the V-shaped and standard tenotomy at 3000 cycles was 1.57 mm (3.66 ± 1.55 mm vs. 5.1 ± 2.8 mm, P = .31, respectively). At no point was the V-shape tenotomy (VT) >3 mm of average displacement, whereas the standard tenotomy (ST) averaged 3 mm of displacement after 3 cycles. Creep was significantly lower for VT in cycles 1 through 3. For all cycles, stiffness was not significantly different in the VT group compared with the ST group. Load to failure was not statistically significant in the VT compared to the standard tenotomy throughout all cycles (253.2 ± 27.7 N vs. 213.3 ± 76.04 N; P = .25, respectively). The range of load to failure varied from 100 to 301 N for standard tenotomy compared with 216 to 308 N for VT. CONCLUSION: This study showed that VT and ST demonstrated equivalent stiffness, displacement, and load to failure. VT had the benefit of less creep throughout the first 3 cycles, although there was no difference from cycle 4 to 3000. The VT had equivalent biomechanical properties to the ST at time zero, an important first step in our understanding of the technique. The VT technique warrants further clinical study to determine if the technique has clinical benefits over ST following aTSA.

Predicting successful outpatient total shoulder arthroplasty.

BACKGROUND: Total shoulder arthroplasty (TSA) is increasingly performed safely and efficiently as an outpatient procedure in certain patients. Patient selection is often based on surgeon choice, surgeon expertise, or institutional guidelines. One orthopedic research group released a publicly available shoulder arthroplasty outpatient appropriateness risk calculator that considers patient demographic characteristics and comorbidities with the aim of helping surgeons to predict successful outpatient TSA. This study aimed to retrospectively assess the utility of this risk calculator at our institution. METHODS: Records were obtained for patients undergoing procedure code 23472 at our institution between January 1, 2018, and March 31, 2021. Patients undergoing anatomic TSA in the hospital setting were included. Records were reviewed for demographic characteristics, comorbidities, American Society of Anesthesiologists classification, and surgery duration. These data were entered into the risk calculator to calculate the likelihood of discharge by postoperative day 1. Charlson Comorbidity Index, complications, reoperations, and readmissions were also collected from patient records. Statistical analyses assessed the model's fit with our patient cohort and compared outcome measures between inpatient and outpatient groups. RESULTS: Of the 792 patients whose records were initially obtained, 289 met the inclusion criteria of anatomic TSA performed in the hospital setting. Of these patients, 7 were excluded because of missing data, leaving 282 patients: 166 (58.9%) in the inpatient group and 116 (41.1%) in the outpatient group. We found no significant differences in mean age (66.4 years in inpatient group vs. 65.1 years in outpatient group, P = .28), Charlson Comorbidity Index (3.48 vs. 3.06, P = .080), or American Society of Anesthesiologists class (2.58 vs. 2.66, P = .19). Surgery time was longer in the inpatient group than the outpatient group (85 minutes vs. 77 minutes, P = .001). Overall complication rates were low (4.2% in inpatient group vs. 2.6% in outpatient group, P = .07). Readmissions and reoperations did not differ between groups. There was no difference in the average percentage likelihood of same-day discharge (55.4% in inpatient group vs. 52.4% in outpatient group, P = .24), and a receiver operating characteristic curve to assess fit with the risk calculator demonstrated an area under the curve of 0.55. DISCUSSION: The shoulder arthroplasty risk calculator performed similarly to chance when retrospectively predicting discharge within 1 day after TSA in our patients. Complications, readmissions, and reoperations were not higher after outpatient procedures. Risk calculators for determining whether a patient should be admitted after TSA should be used cautiously because they may not provide measurable benefit over the use of surgeon experience and expertise in discharge decision making, and other factors may be relevant in the decision to perform outpatient TSA.

Effect of reverse shoulder arthroplasty humeral component retroversion on acromial strain.

INTRODUCTION: Acromion and scapular spine stress fractures can be catastrophic complications following reverse shoulder arthroplasty (RSA). A variety of host, implant, and technical factors have been identified that increase the risk of this complication. The glenoid component in particular has been closely evaluated for its impact on rates of stress fractures following RSA. The goal of this biomechanical study is to evaluate if humeral stem version has an impact on acromion and scapular spine strain after RSA. METHODS: Eight cadaveric specimens were tested on a custom dynamic shoulder frame. Commercially available RSA components were implanted with the humeral component inserted in 0° of retroversion. Acromion and scapular spine strain were measured at 0°, 30°, and 60° of abduction using strain rosettes secured to the acromion and scapular spine in the typical locations for Levy type II and type III stress fractures, respectively. The humeral stem was then removed and reimplanted in 30° of retroversion and the measurements were repeated. Student t test was performed to analyze the relationship between humeral stem version and acromion and scapular spine strain at various abduction angles. RESULTS: Strain at the both the acromion and scapular spine were found to have no significant difference at any abduction angle when comparing 0° and 30° version of the humeral stem. With 0° and 30° versions pooled together, there is significantly lower acromion and scapular spine strain at 60° of abduction when compared to 0° of abduction (strain at 0° abduction - strain at 60° abduction: acromion 313.1 µêœª; P = .0409, Scapular spine 304.9 µêœª; P = .0407). There was no significant difference in strain at either location when comparing 0° of abduction to 30° of abduction and when comparing 30° of abduction to 60° of abduction. CONCLUSIONS: This biomechanical study found no significant difference in scapular spine and acromion strain after RSA when comparing variations in humeral stem version. There does appear to be lower strain at both the acromion and scapular spine at 60° of abduction when compared to 0° of abduction regardless of stem version.

Does a High Postoperative Opioid Dose Predict Chronic Use After ACDF?

OBJECTIVE: The purpose of this study is to determine if increased postoperative prescription opioid dosing is an isolated predictor of chronic opioid use after anterior cervical diskectomy and fusion (ACDF). METHODS: A retrospective cohort analysis of patients undergoing ACDF for degenerative diseases from 2016-2019 at a single institution was performed. Preoperative and postoperative opioid and benzodiazepine prescriptions, including morphine milligram equivalents (MMEs) and duration of use, were obtained from the Pennsylvania Prescription Drug Monitoring Program. Univariate analysis compared patient demographics and surgical factors across groups on the basis of postoperative opioid dose (high: MME ≥90, low: MME <90) and chronicity of use (chronic: ≥120 days or >10 prescriptions). Logistic regressions identified predictors of high opioid dose and chronic use. RESULTS: A total of 385 patients were included. Preoperative opioid tolerance and tobacco use were associated with high postoperative opioid dose and chronic usage. Younger age correlated with high-dose prescriptions. Increased body mass index and preoperative benzodiazepine use were associated with chronic opioid use. Chronic postoperative opioid use correlated with high-dose prescriptions, change in opioid prescribed, private pay scripts, and more than 1 prescriber and pharmacy. Logistic regression identified high postoperative opioid dose, opioid tolerance, increased body mass index, and no prior cervical surgery as predictors of chronic opioid use. Regression analysis determined younger age, increased medical comorbidities, and opioid tolerance to be predictors for high MME prescriptions. CONCLUSIONS: High postoperative opioid dose independently predicted chronic opioid use after ACDF regardless of preoperative opioid tolerance.

Dual Semitendinosus Allograft Reconstruction of Chronic Achilles Tendon Ruptures: Operative Technique and Outcomes.

BACKGROUND: Dual semitendinosus allograft reconstruction of chronic Achilles tendon ruptures has several potential benefits including superior tensile strength compared with a turndown construct and avoidance of the morbidity and operative time associated with autograft augmentation. We present a series of chronic Achilles tendon ruptures reconstructed with dual semitendinosus allograft. METHODS: We retrospectively reviewed the charts of patients aged 18 years and older who underwent reconstruction of chronic Achilles tendon ruptures using dual semitendinosus allograft. The primary outcome of this study was to evaluate the need for revision surgery. Secondary outcomes included patient-reported outcomes, for which Achilles Tendon Rupture Scores (ATRS) were collected at final follow-up. Nine patients with a mean age of 58.9 (range, 43-75) years met inclusion criteria. RESULTS: Median follow-up was 66 months (range, 27-121 months). One patient (11.1%) required revision reconstruction after sustaining graft failure 9.5 years after her index procedure, and 1 patient reported a poor ATRS score at the 27-month final follow-up despite an intact surgical repair. At final follow-up, no patient required the use of an assistive device for ambulation or a walking boot. The median ATRS at final follow-up was 93 (range, 30-100). DISCUSSION: Good clinical outcomes without rerupture were observed in 7 of 9 patients (77.8%) at short- to midterm follow-up, suggesting that dual semitendinosus allograft reconstruction is a viable option for the reconstruction of chronic Achilles tendon tears. LEVEL OF EVIDENCE: Level IV, case series.

The 50 most impactful articles on the medial ulnar collateral ligament: An altmetric analysis of online media.

The purpose of this study was to use the Altmetric Attention Score to determine the 50 most impactful medial ulnar collateral ligament articles in online media and compare their characteristics to the most-cited medial ulnar collateral ligament articles in the scientific literature. The Altmetric database was queried to identify all published articles about the medial ulnar collateral ligament, and this list was stratified by the Altmetric Attention Score to identify the 50 highest scoring articles. Several data elements were extracted, including article topic, article type, journal name, and the number of online mentions on Facebook, Twitter, news, and other platforms. Each article's geographic origin was determined based on the institutional affiliation of the first author. Our index search yielded 1283 articles published between 1987 and 2020, from which the 50 articles with the highest Altmetric Attention Scores were included for analysis. Altmetric Attention Scores of the top 50 medial ulnar collateral ligament articles ranged from 20 to 482 (median: 32, interquartile range: 20-62). The most common article type was original research (72%), and the most common topic was epidemiology/risk factors (26%). A majority of studies were Level 3 (36%) or Level 4 evidence (36%). Of the top 50 medial ulnar collateral ligament articles, 94% originated from the United States. A few articles had a high Altmetric Attention Score, suggesting that medial ulnar collateral ligament research does not generate consistently high online attention. The lack of Level 1 studies suggests the need for high-level studies on the medial ulnar collateral ligament. Most studies originated in the United States and were published in the American Orthopaedic Society for Sports Medicine-affiliated journals. The medial ulnar collateral ligament articles included in this study differed substantially from a previous report of the most-cited medial ulnar collateral ligament articles in the literature, suggesting that alternative metrics add a unique dimension to understanding the overall impact of published research on the medial ulnar collateral ligament.

Effect of glenosphere lateralization with and without coracoacromial ligament transection on acromial and scapular spine strain in reverse shoulder arthroplasty.

Background: Small changes in deltoid tension and moment arm due to glenosphere lateralization may be associated with an increase in acromion or scapular spine strain in reverse shoulder arthroplasty (RSA), which can lead to stress fracture. The coracoacromial ligament (CAL) may be protective and lower the strain seen on the acromion or scapular spine. This biomechanical study investigated the impact of glenosphere lateralization and CAL integrity on acromion and scapular spine strain after RSA. Methods: Ten cadaveric specimens were tested on a custom dynamic shoulder frame. Acromial and scapular spine strain were measured at 0°, 30°, and 60° of abduction using strain rosettes fixed to the acromion (Levy Type 2) and the scapular spine (Levy Type 3). Specimens were first tested with a standard commercially available RSA implant with zero lateralization and then subsequently with the +3 and +6 lateralizing glenospheres for that implant. The CAL was then cut in each specimen and testing was repeated with the 0, +3, and +6 glenospheres. Maximal strain was recorded at both the acromion and scapular spine and analysis of variance compared strain across various abduction angles and glenospheres with and without CAL transection. Results: In the intact CAL group, maximal strain decreased significantly at the acromion with abduction from 0° to 30° and 0° to 60°, however, at the scapular spine abduction did not significantly impact strain. Maximal strain decreased significantly with increasing abduction from 0 to 30 and 0 to 60 at both the acromion and scapular spine in the cut CAL group. Average strain at the acromion was significantly higher in the cut group (844.7 µÎµ) versus the intact group (580.3 µÎµ), a difference of 31.3% (P = .0493). Average strain at the scapular spine, did not differ in the cut group (725 µÎµ) compared with the intact group (787 µÎµ) (P = .3666). There were no statistically significant differences in acromial or scapular spine strain between various levels of glenosphere lateralization in either the cut or intact state. Conclusion: In this biomechanical study, arm abduction decreased acromial and scapular spine strain following RSA. Cutting the CAL significantly increased strain at the acromion, and did not significantly alter strain at the scapular spine for all angles of abduction, differing from prior literature. Glenosphere lateralization did not have a significant effect on strain at the levels studied regardless of CAL status. Continued study of the complexion relationship between surgical and implant factors on strain following RSA is needed.

The 100 most impactful articles on the rotator cuff: an altmetric analysis of online media.

PURPOSE: The purpose of our study was to use the Altmetric Attention Score (AAS) to evaluate the 100 most impactful articles in online media pertaining to the rotator cuff and compare their characteristics to the most-cited rotator cuff articles in the scientific literature. METHODS: We performed an article extraction using Altmetric Explorer to identify all published articles pertaining to the rotator cuff. The top 100 articles with the highest AAS were included for analysis. Several data elements were extracted for each included article: title, article type, article topic, year of publication, journal name, authors, institutional affiliations, and online mentions (i.e. the number of times the article was mentioned in news, blog, Twitter, Facebook, and Wikipedia sources). The geographic origin of each article was also determined by the institutional affiliation of the first author, which was categorized as American (originating in the United States), European (originating in Europe), or other. RESULTS: The 100 articles with the highest AAS were published between 2009 and 2020, with AAS ranging from 47 to 676 (median: 74.5, 25th percentile: 59.5, 75th percentile: 114.5). Of all online media sources, Twitter correlated most strongly with AAS (r = 0.9007, r2 = 0.8112). The selected articles were most frequently published in the American Journal of Sports Medicine (13), the Journal of Shoulder and Elbow Surgery (11), and the Journal of Bone and Joint Surgery (7). The most common article type was Systematic Review/Meta-Analysis (29%), followed by Randomized Controlled Trial (15%). The top 3 AAS articles were all published by authors based in Europe. CONCLUSION: The most impactful rotator cuff articles in online media generated substantial online attention. These studies were often performed in Europe and tended to be high level of evidence, focusing on treatment of rotator cuff pathology. The rotator cuff articles that produced the most online attention differed from a previous report of the most-cited rotator cuff articles, suggesting that alternative metrics may be used in concert with conventional bibliometrics to obtain a more complete representation of scientific impact.

The top 100 most impactful articles on the anterior cruciate ligament: An altmetric analysis of online media.

Objectives: To identify the top 100 most impactful anterior cruciate ligament articles in online media as measured by the Altmetric Attention Score and compare their characteristics to the most-cited anterior cruciate ligament articles in the scientific literature. Methods: The Altmetric database was queried to identify all published articles pertaining to the anterior cruciate ligament. The search yielded 9445 articles, which were stratified by highest to lowest Altmetric Attention Score. The top 100 articles were included. Collected data included article type, article topic, journal name, and online mentions in news, blogs, Twitter, Facebook, Wikipedia, and other sources. The geographic origin of each article was also determined based on the institutional affiliation of the first author. Results: Altmetric Attention Score of the top 100 anterior cruciate ligament articles ranged from 109 to 2193 (median 172.0, interquartile range 137.5-271.5). Of the 100 articles, 65 were published in three journals: American Journal of Sports Medicine, British Journal of Sports Medicine, and Journal of Orthopaedic & Sports Physical Therapy. The most prevalent article type was original research (60%), followed by systematic review/meta-analysis (18%). The most prevalent article topic was rehabilitation and return to play after anterior cruciate ligament reconstruction (22%), followed by epidemiology/risk factors (16%), injury prevention (14%), and biomechanics of anterior cruciate ligament injuries (14%). Of the top 100 articles, 54% were American, 31% were European, and 15% were published in other countries outside of the United States and Europe. Conclusion: This study used Altmetric Attention Score to identify the 100 most engaged anterior cruciate ligament articles in online media. The characteristics of these articles differed substantially from the most-cited anterior cruciate ligament articles in the literature with regard to article type, article topic, geographic origin, and publication journal. These findings suggest that alternative metrics measure distinct components of anterior cruciate ligament article engagement and add an important dimension to understanding the overall impact of published research on the anterior cruciate ligament.

The relationship between academic influence, NIH funding, and industry payments among academic shoulder and elbow surgeons.

BACKGROUND: The effect of academic influence, or the volume and quality of a surgeon's publications, on industry payments and National Institutes of Health (NIH) funding has recently been studied in some academic orthopedic subspecialities. The purpose of this study is to evaluate the relationship between academic influence, industry payments, and NIH funding among American Shoulder and Elbow Surgeons accredited shoulder and elbow fellowship faculty. METHODS: Shoulder and elbow fellowships and affiliated faculty members were identified from the American Shoulder and Elbow Surgeons website. Academic influence, measured by the Hirsch (h)-index, and the number of articles published were determined for faculty members using the Scopus Database Author Identifier tool. Industry payments were derived from the Centers for Medicare and Medicaid Services Open Payments database. NIH funding was determined using the NIH's Research Portfolio Online Reporting tool. Statistical analysis used Spearman correlations and the Mann-Whitney U-test with an alpha value of 0.05 (P < .05). RESULTS: A total of 146 faculty members were included. Twenty-two percent (42 of 146) received nonresearch payments, whereas 78% (114 of 146) received industry research funding averaging $6364 (standard deviation = $21,213). NIH funding averaged $272,589 (standard deviation = $224,635), and 5% received NIH funding (7 of 146). Faculty members who received NIH funding had a higher average h-index than those who did not (38 ± 22 vs. 22.64 ± 22.7, P = .02), whereas those receiving industry research payments had a greater number of publications than those who did not (127.97 ± 127.2 vs. 100.3 ± 122.3, P = .03). Industry nonresearch payments did not impact the number of publications or the h-index. DISCUSSION/CONCLUSION: This study demonstrated that academic influence among academic shoulder and elbow surgeons is not greater in those who receive nonresearch industry funding. However, surgeons with industry research funding did produce more publications, whereas NIH funding is associated with greater academic influence.

Is Patient Geography a Risk Factor for Chronic Opioid Use After ACDF?

The social and medical implications intrinsic to patient zip codes with high opioid fatality may reveal residence in these locations to be a risk factor predicting chronic opioid use after anterior cervical discectomy and fusion (ACDF). The purpose of this study is to determine if residence in Pennsylvania zip codes with high incidence of opioid overdose deaths is a risk factor for chronic postoperative opioid use after ACDF. Preoperative opioid usage did not vary meaningfully between high- and low-risk zip code groups. Patients in high-risk opioid overdose zip codes were significantly more likely to exhibit chronic postoperative opioid use. The Kaplan-Meier curve demonstrated that opioid discontinuation was less probable at any postoperative time for patients residing in high opioid fatality zip codes. Logistic regression found opioid tolerance, smoking, and depression to predict extended opioid use.

The impact of preoperative motor weakness on postoperative opioid use after ACDF.

This study aims to determine if preoperative weakness is an isolated risk factor for prolonged postoperative opioid use after anterior cervical discectomy and fusion (ACDF). Patients with preoperative weakness were significantly more likely to have prolonged and inappropriate opioid use and have a single prescription mean morphine equivalent (MME) ≥ 200. Logistic regression isolated preoperative weakness, opioid tolerance, depression, and VAS Neck pain as independent predictors of extended opioid use. High postoperative opioid dose (MME ≥ 90) correlated with opioid tolerance, younger age, male sex, greater CCI, prior cervical surgery, and preoperative VAS Neck pain on regression.

The Cost of Robot-assisted Total Hip Arthroplasty: Comparing Safety and Hospital Charges to Conventional Total Hip Arthroplasty.

INTRODUCTION: Utilization of robotic assistance is increasing for total hip arthroplasty (THA). However, few studies have directly examined the efficacy of this technique at reducing complications. This research aims to compare the rates of perioperative complications of robotic-assisted THA (RA-THA) with conventional THA (C-THA). METHODS: This study screened more than 35 million hospital discharges between 2010 to 2014 using the National Inpatient Sample. The International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes were used to identify 292,836 patients who underwent C-THA (ICD 81.51) and 946 patients who underwent RA-THA (ICD 81.51 and ICD 17.41, 17.49). Perioperative complications were identified using ICD-9-CM diagnosis codes. Patient mortality was determined using the Uniform Bill patient disposition. The RA-THA cohort was statistically matched 1:1 to C-THA about patient age, sex, race, comorbidities, hospital type, and calendar year. Mean cost and length of stay (LOS) for each cohort were calculated and compared using the Kruskal-Wallis H test. Logistic regression was used to compare the risks of major and minor complications between the cohorts. RESULTS: We matched 758 (80.13%) RA-THA patients with 758 patients who underwent C-THA. No patient in our sample died. When compared with the conventional group, multivariate analysis revealed that the risk of major complications was similar in RA-THA patients (odds ratio = 0.698, 95% confidence interval = 0.282 to 1.727). In addition, although the rate of minor complications was higher in the RA-THA cohort (21.6% versus 12.5%, P = 0.004), no difference was observed on multivariate analysis (odds ratio = 1.248, 95% confidence interval = 0.852 to 1.829). The average inpatient hospital cost of a RA-THA was $20,046 (SD = 6,165) compared with $18,258 (SD = 6,147) for C-THA (P < 0.001). The average LOS was for RA-THA was 2.69 days (SD = 1.25) compared with 2.82 days for C-THA (SD = 1.18, P < 0.001). DISCUSSION: In a statistically matched cohort, the risk of perioperative complication in patients who underwent RA-THA versus C-THA patients were similar. However, RA-THA was costlier despite shorter LOS. LEVEL OF EVIDENCE: Level III, retrospective cohort analysis.

Biomimetic proteoglycans diffuse throughout articular cartilage and localize within the pericellular matrix.

Biomimetic proteoglycan (BPG) diffusion into articular cartilage has the potential to restore the lost proteoglycan content in osteoarthritic cartilage given these molecules mimic the structure and properties of natural proteoglycans. We examined the diffusion characteristics of BPGs through cartilage with the use of a custom-made in vitro cartilage diffusion model in both normal bovine and human osteoarthritic cartilage explants. BPGs were introduced into the cartilage through essentially one-dimensional diffusion using osteochondral plugs. The molecular diffusion was shown to be size and concentration dependent. Diffusion profiles were found over different diffusion time intervals and the profiles were fit to a nonlinear Fickian diffusion model. Steady state 011012-7diffusion coefficients for BPGs were found to be 4.01 and 3.53 µm2 /s for 180 and 1600 kDa BPGs, respectfully, and these values are similar to other large molecule diffusion in cartilage. In both bovine and osteoarthritic human cartilage, BPGs were found localized around the chondrocytes. BPG localization was examined by labeling collagen type VI and soaking 5 µm thick sections of cartilage with BPG solutions demonstrating that the BPGs diffused into the cartilage and preferentially localized alongside collagen type VI in the pericellular matrix.

Orthopaedic Sports Medicine Fellowship Interviews: Structure and Organization of the Interview Day.

BACKGROUND: Over the past few decades, there has been a trend toward an increasing subspecialization in orthopaedic surgery, with orthopaedic sports medicine being one of the most competitive subspecialties. Information regarding the application and interview process for sports medicine fellowships is currently lacking. PURPOSE: To survey orthopaedic sports medicine fellowship program directors (PDs) to better define the structure of the sports medicine fellowship interview and to highlight important factors that PDs consider in selecting fellows. STUDY DESIGN: Cross-sectional study. METHODS: A complete list of accredited programs was obtained from the American Orthopaedic Society for Sports Medicine (AOSSM) website. An anonymous survey was distributed to fellowship PDs of all Accreditation Council for Graduate Medical Education (ACGME)-accredited orthopaedic sports medicine fellowships in the United States. The survey included 12 questions about the fellowship interview and selection process. RESULTS: Of the 95 orthopaedic sports medicine fellowship PDs surveyed, 38 (40%) responded. Of these, 16 (42.1%) indicated that they interview between 21 and 30 applicants per year. Eleven of the 38 fellowship programs (28.9%) have only 1 fellow per year at their respective program. Most programs (27/37, 73%) reported that between 0 and 5 faculty members interview applicants, and 29 of the 38 programs (76.3%) arrange for applicants to have ≥4 interviews during their interview day. Large group interviews are conducted at 36 of 38 (94.7%) sports medicine fellowship programs, and most programs (24/38, 63.2%) hold individual interviews that last between 5 and 15 minutes. The most important applicant criterion taken into account by PDs was the quality of the interview, with an average score of 8.68 of 10. CONCLUSION: The most significant factor taken into account by PDs when deciding how to rank applicants was the quality of the interview. Many orthopaedic sports medicine fellowship programs interview between 21 and 30 applicants per year, with each applicant participating in an average of 2 to 4 individual interviews per interview day and interviews commonly lasting between 5 and 15 minutes.