Kartogenin Induces Chondrogenesis in Cartilage Progenitor Cells and Attenuates Cell Hypertrophy in Marrow-Derived Stromal Cells.

INTRODUCTION: Kartogenin (KGN) is a synthetic small molecule that stimulates chondrogenic cellular differentiation by activating smad-4/5 pathways. KGN has been proposed as a feasible alternative to expensive biologic growth factors, such as transforming growth factor ß, which remain under strict regulatory scrutiny when it comes to use in patients. METHOD: This study reports the previously unexplored effects of KGN stimulation on cartilage- derived mesenchymal progenitor cells (CPCs), which have been shown to be effective in applications of cell-based musculoskeletal tissue regeneration. Our findings demonstrate that KGN treatment significantly increased markers of chondrogenesis, SOX9 and COL2 following 3-10 days of treatment in human CPCs. RESULT: KGN treatment also resulted in a significant dose-dependent increase in GAG production in CPCs. The same efficacy was not observed in human marrow-derived stromal cells (BM-MSCs); however, KGN significantly reduced mRNA expression of cell hypertrophy markers, COL10 and MMP13, in BM-MSCs. Parallel to these mRNA expression results, KGN led to a significant decrease in protein levels of MMP-13 both at 0-5 days and 5-10 days following KGN treatment. CONCLUSION: In conclusion, this study demonstrates that KGN can boost the chondrogenicity of CPCs and inhibit hypertrophic terminal differentiation of BM-MSCs.

The effect of concurrent cervical spine degenerative disease on the outcome of rotator cuff repair: a national database study.

BACKGROUND: Cervical spine degenerative disease (CSD) can cause shoulder pain, potentially confounding the management of patients with rotator cuff tears. This study aimed to investigate the relationships between CSD and rotator cuff repair (RCR). METHODS: A national administrative database (PearlDiver) was used to study 4 patient cohorts: (1) RCR only (RCRo), (2) RCR with concurrent CSD (RCRC), (3) RCR after a cervical spine procedure (RCRA), and (4) RCR before a cervical spine procedure (RCRB). The outcomes of RCR were compared using multivariable logistic regression, controlling for age, sex, and Elixhauser Comorbidity Index, as well as preoperative opioid utilization in the analysis of opioid use. RESULTS: Between 2010 and 2021, a total of 889,977 patients underwent RCR. Of these patients, 784,230 (88%) underwent RCRo whereas 105,747 (12%) underwent RCRC, of whom 21,585 (2.4%) underwent cervical spine procedures (RCRA in 9670 [1.1%] and RCRB in 11,915 [1.3%]). At 2 years after RCR, compared with RCRo patients, RCRC patients had an increased risk of surgical-site infection (adjusted odds ratio [aOR] = 1.25, P = .0004), deep vein thrombosis (aOR = 1.17, P = .0002), respiratory complications (aOR = 1.19, P = .0164), and ipsilateral shoulder reoperations (débridement [aOR = 1.66, P < .0001], manipulation under anesthesia or arthroscopic lysis of adhesions [aOR = 1.23, P < .0001], distal clavicle excision [aOR = 1.78, P < .0001], subacromial decompression [aOR = 1.72, P < .0001], biceps tenodesis [aOR = 1.76, P < .0001], incision and drainage [aOR = 1.34, P = .0020], synovectomy [aOR = 1.48, P = .0136], conversion to shoulder arthroplasty [aOR = 1.62, P < .0001], revision RCR [aOR = 1.77, P < .0001], and subsequent contralateral RCR [aOR = 1.71, P < .0001]). At 2 years, compared with RCRC patients who did not undergo cervical spine procedures, RCRC patients who underwent cervical spine procedures had an increased risk of incision and drainage (aOR = 1.50, P = .0255), conversion to arthroplasty (aOR = 1.40, P < .0001), and revision RCR (aOR = 1.11, P = .0374), as well as a lower risk of contralateral RCR (aOR = 0.89, P = .0469). The sequence of cervical spine procedures did not affect the risk of shoulder reoperations. At 1 year, the risk of opioid use after RCR was less for RCRA patients compared with RCRB patients (aOR = 1.71 [95% confidence interval, 1.61-1.80; P < .0001] vs. aOR = 2.01 [95% confidence interval, 1.92-2.12; P < .0001]). CONCLUSION: Concurrent CSD has significant detrimental effects on RCR outcomes. Patients with concurrent CSD undergoing cervical spine procedures have a greater risk of ipsilateral shoulder reoperations but a decreased risk of contralateral RCR. The risk of prolonged opioid use was lower if RCR followed a cervical spine procedure. Concurrent CSD must be considered and possibly treated to optimize the outcomes of RCR.

Chronic obstructive pulmonary disease is an independent risk factor for increased opioid use in total hip arthroplasty: A retrospective PearlDiver study.

Background: Total hip arthroplasty (THA) has become an incredibly common procedure due to its' predictability and high success rate. The success of surgery is related to strict indications and careful optimization of medical comorbidities to decrease risk and improve outcomes. Chronic obstructive pulmonary disease (COPD) has been associated with increased medical and surgical complications. A regulatory focus on opioid utilization does not usually consider COPD as a risk factor, but limited research exists on the impact of COPD on outcomes and risks after THA. Methods: Retrospective all-inclusive database analysis of Medicare patients who had undergone THA between 2007 and 2017 included in the PearlDiver Database were studied. Postoperative opioid usage was examined at 1-, 3-, 6-, and 12 months, along with surgical infection, implant complications, and revisions. Post-operative complications within 30 days, either medical or implant related, were identified. Controlling for comorbidities, age, and sex, odds ratios were calculated using multivariable logistic regression with a significant α value of 0.05. Results: COPD patients had significantly higher rates of opioid usage postoperatively. COPD patients also had an increased rate of readmissions, medical/implant complications, and revision surgeries. Discussion: This is the only study raising concern regarding opioid use in COPD patients after total hip arthroplasty, which may be critical considering the associated respiratory depression further exacerbating the COPD. Considering the evidence of poor outcomes associated with COPD in arthroplasty, appropriately screening for COPD and counseling or planning for post-operative pain control and complications is paramount.

Risk Factors and Outcomes for Preoperative Stiffness Requiring Intervention Before Anterior Cruciate Ligament Reconstruction.

Background: To date, there is a scarcity of literature related to the incidence of prolonged stiffness after an anterior cruciate ligament (ACL) tear that requires manipulation under anesthesia/lysis of adhesions (MUA/LOA) in the preoperative period before ACL reconstruction (ACLR) and how preoperative stiffness influences outcomes after ACLR. Hypothesis: Preoperative stiffness requiring MUA/LOA would increase the risk for postoperative stiffness, postoperative complications, and the need for subsequent procedures after ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: The PearlDiver Research Program was used to identify patients who sustained an ACL tear and underwent ACLR using their respective International Classification of Diseases, 9th or 10th Revision, and Current Procedure Terminology (CPT) codes. Within this group, patients with preoperative stiffness were identified using the CPT codes for MUA or LOA. Significant risk factors for preoperative stiffness were identified through univariate and multivariate logistic regression analyses. Outcomes after ACLR were analyzed between patients with and without preoperative stiffness using multivariate logistic regression, controlling for age, sex, and Elixhauser Comorbidity Index. Results: Between 2008 and 2018, 187,071 patients who underwent ACLR were identified. Of these patients, 241 (0.13%) underwent MUA/LOA before ACLR. Patients with preoperative stiffness began preoperative physical therapy significantly later than patients without stiffness (P = .0478) and had a delay in time to ACLR (P = .0003). Univariate logistic regression demonstrated that female sex, older age, anxiety/depression, obesity, and anticoagulation use were significant risk factors for preoperative stiffness (P < .05 for all). After multivariate regression, anticoagulation use was the only independent risk factor deemed significant (odds ratio, 6.69 [95% CI, 4.01-10.51]; P < .001). Patients with preoperative stiffness were at an increased risk of experiencing postoperative stiffness, deep vein thrombosis, pulmonary embolism, surgical-site infection, and septic knee arthritis after ACLR (P < .05 for all). Conclusion: Although the risk of preoperative stiffness requiring an MUA/LOA before ACLR is low, the study findings indicated that patients with preoperative stiffness were at increased risk for postoperative complications compared with patients with no stiffness before ACLR.

Complications and Reoperation Following Surgery for Concurrent Carpal Tunnel and Cervical Spine Compression.

BACKGROUND: Patients with carpal tunnel syndrome (CTS) may also have cervical radiculopathy (CR) or vice versa, potentially requiring carpal tunnel release (CTR) and anterior cervical discectomy and fusion (ACDF). This study evaluates whether there is an increased risk of complications following CTR or ACDF in patients with concurrent CTS and CR (CTS-CR) compared with those with only CTS or CR. METHODS: A multipayer database was used to identify patients with CTS-CR. From this cohort, patients who underwent CTR and/or ACDF were identified. Patients with CTS-CR undergoing surgery were compared with those undergoing surgery with only CTS or CR. Multivariable logistic regression was used to compare matched populations to assess postoperative complications and risk of undergoing both procedures. RESULTS: A total of 110 379 patients with CTS-CR were identified. Carpal tunnel release was performed in 21 152 patients (19.2%) with CTS-CR, from which 835 (0.76%) underwent ACDF. Anterior cervical discectomy and fusion was performed in 6960 patients (6.31%) with CTS-CR followed by CTR in 1098 patients (0.99%). Patients with CTS-CR were at greater risk of reoperation and complex regional pain syndrome following CTR. In ACDF, patients with CTS-CR were at greater risk of reoperation. Obesity and tobacco use were significant risk factors in patients with CTS-CR who underwent both CTR and ACDF rather than a single surgery. CONCLUSIONS: Examination of more than 100 000 patients with CTS-CR found a greater likelihood of reoperation and perioperative complications following surgery than those without concurrent diagnoses. Obesity and smoking increased the risk for patients undergoing both procedures. Patients presenting with CTS-CR are high risk and should be counseled on risk of complication and reoperation and optimized to reduce risk of undergoing both CTR and ACDF.

YouTube as a Source of Patient Information for Cubital Tunnel Syndrome: An Analysis of Video Reliability, Quality, and Content.

BACKGROUND: This study seeks to examine the reliability, quality, and content of YouTube videos on cubital tunnel syndrome, on which there is presently a paucity of information. METHODS: The top 50 unique YouTube videos by relevance resulting from the Boolean search term "cubital tunnel + cubital tunnel syndrome" were identified, with video properties for analysis including source, upload date, duration, views, and comments. Content was assessed using the Journal of American Medical Association (JAMA) criteria, the Global Quality Score (GQS), and a "Cubital Tunnel-Specific Score" (CTSS). RESULTS: The average video saw 72 108 ± 199 362 views, with videos produced by allied (nonphysician) health professionals demonstrating the highest mean views (111 789 ± 294 471 views). Videos demonstrated low mean JAMA scores (2.4/4 ± 0.7), GQS (2.8/5 ± 1.3), and CTSS (7.5/21 ± 4.3), with academic and nonacademic physician videos demonstrating significantly greater mean GQS and CTSS scores when compared with videos by allied health professionals. Positive independent predictors for GQS included academic sources (ß = 1.871), nonacademic physician sources (ß = 1.651), and video duration (ß = 0.102), which were likewise positive predictors for CTSS (ß = 4.553, 4.639, 0.374). Content relating to surgical techniques or approaches for cubital tunnel decompression had the greatest CTSS scores (11.2 [4.2]). CONCLUSIONS: YouTube is a source of highly accessible information on cubital tunnel syndrome, although the average video presents generally poor and inadequate information. Directing patients toward higher quality video resources can be a meaningful component of patient education.

Recurrence of Hamstring Injuries and Risk Factors for Partial and Complete Tears in the National Football League: An Analysis From 2009-2020.

PURPOSE: To (1) characterize hamstring injury (HSI) recurrence rates across the 2009-2010 to 2019-2020 NFL seasons and (2) to identify HSI recurrence risk factors among positions and determine the weekly return to play (RTP) recurrence risk. We hypothesized that older players, skill position players, and players returning to play faster were most at risk. METHODS: Public data from the 2009-2010 to 2019-2020 seasons were reviewed to identify HSIs. Player characteristics were collected before and two seasons following injury. A week-by-week analysis of recurrence risk was evaluated with linear and logarithmic trendlines of the best fit. RESULTS: A total of 2075 HSI were identified with a mean age of 26.2 years (20.0-43.0), BMI of 29.6 (22.7-43.5), and 3.4 seasons of experience (0-17), with 1826 strains (88.0%), 236 partial tears (11.3%), and 13 complete tears (0.63%). Of the 2075 injuries, 796 (38.4%) were recurrent, with 247 (11.9%) being a same-season reinjury. Logistic regression found that fewer weeks before RTP, in-game injury, and lower BMI were risk factors for same-season recurrence. For any recurrence, logistic regression identified more recent year of injury, lower BMI, and longer playing experience as significant risk factors. Wide receivers were found to be at risk for same-season recurrence. For any-season recurrence, defensive backs, linebackers, running backs, tight ends, and wide receivers were at risk. Week-by-week recurrence analysis determined the greatest risk to be when players returned within 2 weeks (13.4%). CONCLUSIONS: There is a high rate of HSI recurrence in the NFL. Risk factors for same-season injury include shorter time to RTP, in-game injury, lower BMI, and playing wide receiver. Risk factors for any-season recurrence were more recent year of injury, lower BMI, longer playing experience, and playing defensive back, linebacker, running back, tight end, or wide receiver. The greatest risk factor for HSI recurrence was RTP within 2 weeks.

Chronic Obstructive Pulmonary Disease Associated with Prolonged Opiate Use, Increased Short-Term Complications, and the Need for Revision Surgery following Total Knee Arthroplasty.

Chronic obstructive pulmonary disease (COPD) is a condition which causes a substantial burden to patients, physicians, and the health care system at large. Medical comorbidities are commonly associated with adverse health outcomes in the postoperative period. Here, we present a large database review of patients undergoing total knee arthroplasty (TKA) to determine the effect of COPD on patient outcomes. The PearlDiver database was queried for all patients who underwent TKA between 2007 and the first quarter of 2017. Medical complications, surgical complications, 30-day readmission rates, revision rates, and opioid utilization were assessed at various intervals following TKA among patients with and without COPD. Multivariable regression was used to calculate adjusted odds ratios controlling for age, sex, and medical comorbidities. A total of 46,769 TKA patients with COPD and 120,177 TKA patients without COPD were studied. TKA patients with COPD experienced increased risk of 30-day readmission (40.8% vs. 32.2%, p < 0.0001), 30-day total medical complications (10.2% vs. 7.0%, p < 0.0001), prosthesis explanation at 6 months (0.4% vs. 0.2, p = 0.0130), 1 year (0.6% vs. 0.3%, p = 0.0005), and 2 years (0.8% vs. 0.5%, p = 0.0003), as well as an increased rate of revision (p < 0.0046) compared to TKA patients without COPD. Opioid utilization of TKA patients with COPD was greater significantly than that of TKA patients without COPD at 3, 6, and 12 months. Patients with COPD have an increased risk for medical and surgical complications, readmission, and prolonged opioid use following TKA.

Risk of Dislocation and Revision Following Primary Total Hip Arthroplasty in Patients With Prior Lumbar Fusion With Spinopelvic Fixation.

BACKGROUND: The effect of spinopelvic fixation in addition to lumbar spinal fusion (LSF) on dislocation/instability and revision in patients undergoing primary total hip arthroplasty (THA) has not been reported previously. METHODS: The PearlDiver Research Program was used to identify patients aged 30 and above undergoing primary THA who received (1) THA only, (2) THA with prior single-level LSF, (3) THA with prior 2-5 level LSF, or (4) THA with prior LSF with spinopelvic fixation. The incidence of THA revision and dislocation/instability was compared through logistic regression and Chi-squared analysis. All regressions were controlled for age, gender, and Elixhauser Comorbidity Index (ECI). RESULTS: Between 2010 and 2018, 465,558 patients without history of LSF undergoing THA were examined and compared to 180 THA patients with prior spinopelvic fixation, 5,299 with prior single-level LSF, and 1,465 with prior 2-5 level LSF. At 2 years, 7.8% of THA patients with prior spinopelvic fixation, 4.7% of THA patients with prior 2-5 level LSF, 4.2% of THA patients with prior single-level LSF, and 2.2% of THA patients undergoing only THA had a dislocation event or instability (P < .0001). After controlling for length of fusion, pelvic fixation itself was associated with higher independent risk of revision (at 2 years: 2-5 level LSF + spinopelvic fixation: aHR = 3.15, 95% CI 1.77-5.61, P < .0001 vs 2-5 level LSF with no spinopelvic fixation: aOR = 1.39, 95% CI 1.10-1.76, P < .0001). CONCLUSION: At 2 years, spinopelvic fixation in THA patients were associated with a greater than 3.5-fold increase in hip dislocation risk compared to those without LSF, and an over 2-fold increase in THA revision risk compared to those with LSF without spinopelvic fixation. LEVEL OF EVIDENCE: III.

YouTube as a Source of Patient Information for Ankle Arthroplasty: Quantitative Analysis of Video Reliability, Quality, and Content.

Background. There are limited data on the quality and content of videos discussing total ankle arthroplasty (TAA) on the YouTube video platform. Methods. The first 60 unique YouTube videos resulting from the keyword query "ankle arthroplasty" and "ankle replacement" were analyzed for comprehensiveness and quality. Content was assessed using the Journal of American Medical Association (JAMA) benchmark criteria, DISCERN, Global Quality Scale (GQS), and an arthroplasty-specific score. Results. Videos demonstrated low mean DISCERN (49.2/80), GQS (3.2/5), and arthroplasty-specific scores (4.3/12) with substantial variability between videos. Most of the content was produced by nonacademic physicians (46.7%) and academic sources (21.7%). Academic videos saw significantly higher mean JAMA scores (P = .013) but were otherwise comparable to non-academic physicians. Commercial content demonstrated significantly low-quality scores compared to academic (P = .012) and physician (P = .008) sources despite the highest mean viewership. Conclusions. Information on TAA on the YouTube platform is highly variable based on video source, with generally poor quality and content.Level of Evidence: Level V, systemic review of non-peer reviewed resources.

The Effect of Early versus Late Manipulation Under Anesthesia on Opioid Use, Surgical Complications, and Revision Following Total Knee Arthroplasty.

Previous studies of early versus late manipulation under anesthesia (MUA) do not report on postoperative opioid utilization or revisions and focused on small single-institution retrospective cohorts. The PearlDiver Research Program (www.pearldiverinc.com), which uses an all-inclusive insurance database, was used to identify patients undergoing primary total knee arthroplasty (TKA) who received (1) late MUA (>12 weeks), (2) early MUA (≤12 weeks), or (3) TKA only. To develop the control group cohort of TKA-only patients, 3:1 matching was conducted using 11 risk factor variables deemed significant by chi-squared analysis. Complications and opioid utilization were compared through multivariate regression analysis, controlling for age, gender, and Charlson Comorbidity Index. The risk of TKA revision was assessed through Cox-proportional hazards modeling and Kaplan-Meier survival analysis with log-rank test. Between 2011 and 2017, 2,062 TKA patients with early MUA, 1,112 TKA patients with late MUA, and a control cohort of 8,327 TKA-only patients were identified in the database. The percent of patients registering opioid use decreased from 54.6% 1 month pre-MUA to 4.6% (p < 0.0001) 1 month post-MUA following early MUA, whereas only from 32.6 to 10.4% (p < 0.0001) following late MUA. Late MUA was associated with higher risk of repeat MUA at 6 months (adjusted odds ratio [aOR] = 2.74, p < 0.0001), 1 year (aOR = 2.66, p < 0.0001), and 2 years (aOR = 2.63, p < 0.0001) following index MUA. Hazards modeling and survival analysis showed increased risk of TKA revision following late MUA (adjusted hazard ratio [aHR] = 3.50, 95% confidence interval [CI]: 2.77-4.43, p < 0.0001) compared to early MUA (aHR = 2.15, 95% CI: 1.72-2.70, p < 0.0001), with significant differences in survival to revision curves (p < 0.0001). When compared to early MUA at 1 year, late MUA was associated with a significantly increased risk of prosthesis explantation (aOR = 2.89, p = 0.0026 vs. aOR = 0.93, p = 0.8563). MUA within 12 weeks after index TKA had improved pain resolution and significant curtailing of opioid use. Furthermore, late MUA was associated with prolonged opioid use, increased risks of revision, as well as prosthesis explantation, supporting screening and early intervention in cases of slow progression and stiffness. The level of evidence of this study is III.

Comparative Effectiveness of Sacroiliac Belt versus Lumbar Orthosis Utilization on Nonspecific Low Back Pain: a Crossover Randomized Clinical Trial.

Background: Back braces are commonly utilized in the management of low back pain (LBP). Objective: The aim of this study is to evaluate (1) user satisfaction with a sacroiliac belt versus a lumbar orthosis and (2) the effect of a sacroiliac belt versus a lumbar orthosis on pain, functional disability status, and analgesic use for subjects with subacute or chronic non-specific LBP. Methods: This is a prospective randomized crossover study. For the two-week study period, control group subjects wore the Horizon 627 Lumbar Brace ("lumbar orthosis") during the first week and the Serola Sacroiliac Belt ("sacroiliac belt") during the second week; experimental group subjects wore the sacroiliac belt during the first week and the lumbar orthosis during the second week. User satisfaction (Quebec User Evaluation of Satisfaction with Assistive Technology 2.0 [QUEST 2.0] score), functional disability status (Oswestry Disability Index [ODI]), pain, and analgesic use were recorded. Results: Overall, the sacroiliac belt demonstrated significantly higher user satisfaction than the Horizon brace (QUEST Score = 20.31 vs. 16.17, p = 0.0375) for the entire study period. Significant negative correlations were identified between user satisfaction and functional disability (t = -4.71, p < 0.0001), pain magnitude (t = -6.81, p < 0.0001) as well as pain frequency (t = -6.66, p < 0.0001). Conclusion: In this prospective randomized crossover study, subject satisfaction was associated with improvements in functional disability, pain magnitude and pain frequency. The sacroiliac belt demonstrated significantly higher user satisfaction and similar effectiveness compared to the lumbar orthosis.

Risk of Dysphagia and Dysphonia in Patients With Prior Thyroidectomy Undergoing Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective cohort study using PearlDiver database. OBJECTIVES: To evaluate the effect of prior thyroidectomy on complications of Anterior Cervical Discectomy and Fusion (ACDF) surgery. METHODS: PearlDiver was used to identify patients without prior dysphagia or dysphonia undergoing ACDF between the years 2010-2020Q1. Patients with and without prior thyroidectomy were matched by levels of fusion, alcohol use, and gastroesophageal reflux disease in a 1:5 ratio. Postoperative outcomes were assessed for each cohort with multivariable logistic regression, controlling for age, sex, and Elixhauser Comorbidity Index. RESULTS: Between 2010 and 2019, matched cohorts of 792 ACDF patients with prior thyroidectomy and 3960 ACDF only patients were included in the study. Of patients with previous thyroidectomy undergoing ACDF, 16.3% experienced dysphagia at 1-year compared with 10.6% for patients undergoing ACDF only (aOR=1.39, P=.004). Patients with previous thyroidectomy also had higher odds of dysphonia at 1-year following ACDF, as compared to patients with ACDF alone (2.7% vs 1.2%, aOR=1.74, P= .048). Patients undergoing ACDF with prior thyroidectomy did not have increased risk of revision at 1 year (aOR=1.10, P=.698), 2 years (aOR=1.16, P=.457), or 5 years (aOR=1.20, P=.255) following surgery. There were no differences in postoperative opioid utilization rates at 1 month (aOR=2.07, P=.138), 3 months (aOR=2.45, P=.095), 6 months (aOR=1.34, P=.520), and 12 months (aOR=1.69, P=.202). Prior thyroidectomy was not associated with reintubation following ACDF (P=.995). CONCLUSIONS: Patients with prior thyroidectomy undergoing ACDF surgery experience increased odds of dysphagia and dysphonia at 1-year follow-up compared to those without prior thyroidectomy.

Quadruped Gait and Regulation of Apoptotic Factors in Tibiofemoral Joints following Intra-Articular rhPRG4 Injection in Prg4 Null Mice.

Camptodactyly-arthropathy-coxa vara-pericarditis (CACP) syndrome leads to diarthrodial joint arthropathy and is caused by the absence of lubricin (proteoglycan 4-PRG4), a surface-active mucinous glycoprotein responsible for lubricating articular cartilage. In this study, mice lacking the orthologous gene Prg4 served as a model that recapitulates the destructive arthrosis that involves biofouling of cartilage by serum proteins in lieu of Prg4. This study hypothesized that Prg4-deficient mice would demonstrate a quadruped gait change and decreased markers of mitochondrial dyscrasia, following intra-articular injection of both hindlimbs with recombinant human PRG4 (rhPRG4). Prg4-/- (N = 44) mice of both sexes were injected with rhPRG4 and gait alterations were studied at post-injection day 3 and 6, before joints were harvested for immunohistochemistry for caspase-3 activation. Increased stance and propulsion was shown at 3 days post-injection in male mice. There were significantly fewer caspase-3-positive chondrocytes in tibiofemoral cartilage from rhPRG4-injected mice. The mitochondrial gene Mt-tn, and myosin heavy (Myh7) and light chains (Myl2 and Myl3), known to play a cytoskeletal stabilizing role, were significantly upregulated in both sexes (RNA-Seq) following IA rhPRG4. Chondrocyte mitochondrial dyscrasias attributable to the arthrosis in CACP may be mitigated by IA rhPRG4. In a supporting in vitro crystal microbalance experiment, molecular fouling by albumin did not block the surface activity of rhPRG4.

Performance After Concussion in National Basketball Association Players.

Background: Concussions have received national attention in collision sports such as football, soccer, and hockey, but less focus has been placed on basketball. Purpose: To determine return-to-play (RTP) and player performance in the first and second season after concussion in National Basketball Association (NBA) players. Study Design: Descriptive epidemiology study. Methods: An online database of publicly available NBA athlete injuries was queried for instances of "concussion" between 2010 and 2018. The age at injury, team, position, height, weight, body mass index, NBA experience, date of concussion, date of return, and seasons played postconcussion was recorded for each player. Regular-season statistics (games started, games played, minutes played, and player efficiency rating [PER]) were compiled for the season before, and 2 seasons immediately after, injury. Kaplan-Meier survivorship plots were computed for athlete RTP and retirement endpoints. Results: A total of 81 injuries were identified from 2010 to 2018, with a rate of 2.0 concussions per 100 player-years. Overall RTP was 100% after concussion, with nearly all (88%) returning in the season of injury; 12% of players experienced a season-ending concussion. RTP averaged 37.3 days after injury, varying widely (range, 2-291 days). Compared with preinjury season (78.0%), athletes played in significantly fewer overall games in the season of injury (36.6%; P < .0001), as well as 1 (69.5%; P = .0229) and 2 seasons postinjury (73.2%; P = .3192). PER scores were not significantly different across the study period. Each point increase in a player's preinjury PER score was associated with a 2.4% decrease in PER from the preinjury season to season of injury (P = .0016) and a 3.1% decrease from preinjury to season after injury (P = .0053). Each increasing year of age or year of experience was associated with 5% decline in PER score at 1 season after injury. Conclusion: NBA players had a high RTP after concussion, with most returning in the same season as the injury. Players sustaining concussions played significantly fewer games for at least 2 seasons after injury. Performance via PER did not change across the entire cohort; however, players with higher preinjury PER, and older players were more likely to sustain a greater decline in performance after injury.

Defining the contemporary epidemiology and return to play for high ankle sprains in the National Football League.

BACKGROUND: High ankle sprains and syndesmotic injuries are commonly sustained by National Football League players, yet there is apaucity of literature reporting the incidence, risk factors and return to play (RTP) rates for these injuries. The purpose of this study is to examine the epidemiology and trends in incidence of high ankle sprains across 11 NFL seasons. METHODS: Publicly available data from the 2009-2010 through 2019-20 seasons were reviewed to identify injuries and collect player characteristics and return to play. Incidence of high ankle injuries was calculated per 10,000 athlete-exposures. Linear regression was performed for incidence of injuries. Risk factors for failure to RTP were identified through multivariate logistic regression, controlling foryear of injury, player position, body mass index (BMI), age at injury, and years of experience before injury. RESULTS: A total of 533 high ankle sprains were identified in 498 players at an average age of 25.8 ± 3.1 and average BMI of 31.8 ± 4.6. The annual incidence of high ankle sprains in the NFL increased at alinear rate of 0.067per 10,000 player exposures (R2 = 0.3357) in 2009, to 1.75per 10,000 player exposures to 2.49 in 2019-20. Most injuries were in offensive players (304/533 injuries, 57.0%). Overall, 89.7% (478/533) of players returned to play; average RTP time was 80.5 ± 132.9 days. Defensive players had afaster RTP (68.1 ± 114.6 days) compared to offensive players (90.1 ± 144.8 days) (p = 0.084). Higher age at injury was found to increase the risk of failure to RTP (p = 0.0088). CONCLUSION: RTP rate was high following high ankle sprain aamongNFL players at 90%, with an average recovery period of 11 weeks. Defensive players experience RTP faster than offensive players. Future studies are needed to determine performance outcomes following RTP, along with which patients might benefit from surgery.

Influence of Preseason Versus In-Season Play on Achilles Tendon Injuries in the National Football League.

BACKGROUND: A ruptured Achilles tendon (AT) can sideline a player for 6 to 12 months and reduce their power rankings by more than 50%. Previous research has compared AT rupture rates in different game conditions. PURPOSE: To determine environmental and physiological risk factors for AT tears, given the minimal amount of research on AT ruptures in the National Football League (NFL). STUDY DESIGN: Case series; Level of evidence, 4. METHODS: NFL players with a diagnosed AT tear between 2009 and 2016 were selected as the study population for this retrospective analysis. Data on NFL injury were collected from an established database composed of publicly available information. Player profiles were employed to determine position, team, and game statistics at the time of injury. The proportion of NFL rookies was approximated by summing the number of draft picks and the number of signed, undrafted free agents and measured against the number of roster spots before the season. RESULTS: Between 2009 and 2016, there were 101 documented AT tears. Of these, 64% (65/101) occurred before the official season, including preseason games. Of the 36 tears that occurred in-season, 34 were during games. Overall, 29% (19/65) of the preseason tears occurred in rookies and 100% (36/36) of the in-season tears affected nonrookies. Of the rookies with AT ruptures, 42.11% returned to play in the NFL, while 62.20% of the nonrookies came back to partake in future seasons. Despite an average age of 26.7 years, the tear distribution was bimodal with players aged 24 and 36 years exhibiting the highest rates of tear. CONCLUSION: In our review of AT tears in NFL athletes, a large percentage of the tears occurred in rookie players, especially during the preseason. We also found that tears during the season occurred in only nonrookies, suggesting that the preseason is when rookies experience the greatest risk for injury.

Total Hip Arthroplasty After Hip Arthroscopy Has Increased Complications and Revision Risk.

BACKGROUND: There has been an increase in hip arthroscopy (HA) over the last decade. After HA, some patients may ultimately require a total hip arthroplasty (THA). However, there is a scarcity of research investigating the outcomes in patients undergoing THA with a history of ipsilateral HA. METHODS: The PearlDiver research program (www.pearldiverinc.com) was queried to capture all patients undergoing THA between 2015 and 2020. Propensity matching was performed to match patients undergoing THA with and without a history of ipsilateral THA. Rates of 30-day medical complications, 1-year surgical complications, and THA revision were compared using multivariate logistic regression. Kaplan-Meier analysis was conducted to estimate survival probabilities of each of the groups with patients undergoing THA . RESULTS: After propensity matching, cohorts of 1940 patients undergoing THA without prior HA and 1940 patients undergoing a THA with prior HA were isolated for analysis. The mean time from HA to THA was 1127 days (standard deviation 858). Patients with a history of ipsilateral HA had an increased risk for dislocation (odds ratio [OR] 1.56, P = .03) and overall decreased implant survival within 4 years of undergoing THA (OR 1.53; P = .05). Furthermore, our data demonstrate the timing of previous HA to be associated with the risk of complications, as illustrated by the increased risk for dislocation (OR 1.75, P = .03), aseptic loosening (OR 2.18, P = .03), and revision surgery at 2 (OR 1.92, P = .02) and 4 years (OR 2.05, P = .01) in patients undergoing THA within 1 year of HA compared twitho patients undergoing THA more than 1 year after HA or with no previous history of HA. CONCLUSION: Patients undergoing THA after HA are at an increased risk for surgical complications, as well as the need for revision surgery.

Performance and Survivorship of National Football League Players with Pectoralis Major Injuries.

PURPOSE: The purpose of this study was to determine return-to-play (RTP), performance and career survivorship for National Football League (NFL) athletes sustaining pectoralis major (PM) injuries with comparison among grades of injury and between nonoperative and operative management. METHODS: Publicly available data from the 1998-2020 NFL seasons were reviewed to identify athletes with PM injuries. Athlete characteristics were collected 1 season before and 2 seasons after injury. Percent of total games played in a season, player efficiency rating (PER), and Pro Football Focus (PFF) grades were compared for the preinjury season and 2 postinjury seasons. Kaplan-Meier survivorship plots were computed for RTP and postinjury career length, whereas a log-rank test was used to compare survivorship differences. RESULTS: In total, 258 PM injuries were reported at a mean age of 27.1 ± 3.3 years. A total of 126 surgical repairs occurred in 48.8% (n = 126) of injuries, with athletes undergoing repair possessing a lower RTP rate and longer time to RTP compared to athletes treated conservatively (P < .001). Survival analysis revealed shorter career length for athletes sustaining PM tears compared to strains (P < .001), although no difference in career length was appreciated on the basis of injury management (P = .980). Defensive linemen and wide receivers had lower PER during their second postinjury seasons (P = .019 and .030, respectively), whereas defensive linemen had lower PFF grades during their second post-injury seasons (P = .044). CONCLUSION: NFL athletes requiring PM repair may experience a lower likelihood of RTP, and longer RTP timing, likely because of higher-grade injuries. Defensive linemen and wide receivers experiencing PM injuries are at risk for diminished performance post-injury. Career length does not appear to be affected based on injury management. LEVEL OF EVIDENCE: Level III, cohort study.

Incidence of Pectoralis Major Injuries Has Increased 40% Over the Last 22 National Football League Seasons.

PURPOSE: To examine trends in the incidence of pectoralis major (PM) injuries over the last 22 National Football League (NFL) seasons and identify risk factors for injuries requiring operative management. METHODS: Publicly available data from the 1998-1999 through 2019-2020 NFL seasons were reviewed to identify PM injuries, demographics, injury mechanisms, and management. Injury incidence was calculated using linear regression per 10,000 athlete-exposures, while risk factors for operative management were identified through multivariate logistic regression. RESULTS: There were 258 PM injuries. Mean athlete age at the time of injury was 27.1 years (range: 21-37) with a mean body mass index of 32.6 (range: 24.8-43.1). Overall incidence was 0.603 per 10,000 athlete-exposures, which was found to significantly increase with time by 0.039 per athlete-exposures per year (R 2 = .787, P < .001). Defensive athletes accounted for 64.7% of PM injuries. Repair was performed in 48.8% of athletes, with defensive linemen (odds ratio [OR] 3.78, CI 1.42-10.60, P = .009), defensive backs (OR 12.20, CI 2.13-76.60, P = .006), linebackers (OR 8.98, CI 2.58-33.60, P < .001), more recent time of injury (OR 1.11, CI 1.05-1.17, P < .001), and shorter NFL experience (OR .77 for older athletes, CI .59-.99), P = .047) at significant risk for operative treatment. CONCLUSION: A total of 258 PM injuries were identified over 22 NFL seasons, with an overall incidence of 0.603 per 10,000 athlete-exposures, which was found to increase by 0.039 injuries per 10,000 athlete-exposures per year. Repair was performed in 48.8% of athletes, with more recent time of injury, shorter NFL experience, defensive linemen, defensive backs and linebackers at significantly higher risk for operative treatment. STUDY DESIGN: Cohort study; Level of evidence, 3.