Obesity and perioperative adverse events in patients undergoing complex revision surgery for the thoracolumbar spine.

BACKGROUND: There are no previous studies that evaluate the effect of obesity on patients undergoing complex revision thoracolumbar spine surgery. The primary objective was to determine the relationship between obesity and perioperative adverse events (AEs) with patients undergoing complex revision thoracolumbar spine surgery while controlling for psoas muscle index (PMI) as a confounding variable. The secondary objective was to determine the relationship between obesity and 30-day readmission rates, 30-day re-operation rates, rate of discharge to a facility, and post-operative length of stay (LOS). METHODS: Between May 2016 and February 2020, a retrospective analysis of individuals undergoing complex revision surgery of the thoracolumbar spine was performed at a single institution. Obesity was defined as BMI ≥ 30.0 kg/m2. PMI < 500 mm2/m2 for males and < 412 mm2/m2 for females were used to define low muscle mass. A Spine Surgical Invasiveness Index (SSII) > 10 was used to define complex revision surgery. A multivariable logistic regression model was used to ascertain the effects of low muscle mass, obesity, age, and gender on the likelihood of the occurrence of any AE. RESULTS: A total of 114 consecutive patients were included in the study. Fifty-four patients were in the obese cohort and 60 patients in the non-obese cohort. There was not a significant difference in perioperative outcomes of both the obese and non-obese patients. There were 22 obese patients (40.7%) and 33 non-obese patients (55.0%) that experienced any AE (p = 0.130). Multivariable analysis demonstrated that individuals with low muscle mass had a significantly higher likelihood for an AE than individuals with normal or high muscle mass (OR: 7.53, 95% CI: 3.05-18.60). Obesity did not have a significant effect in predicting AEs. CONCLUSIONS: Obesity is not associated with perioperative AEs, 30-day readmission rates, 30-day re-operation rates, rate of discharge to a facility, or post-operative length of stay (LOS) among patients undergoing complex revision thoracolumbar spine surgery. LEVEL OF EVIDENCE: III.

Sham Surgery Studies in Orthopaedic Surgery May Just Be a Sham: A Systematic Review of Randomized Placebo-Controlled Trials.

PURPOSE: To determine the limitations of randomized sham surgery-controlled trials in orthopaedic sports medicine and fidelity of the trials' conclusions. METHODS: Randomized placebo surgery-controlled trials in orthopaedic sports medicine were included in this Preferred Reporting Items for Systematic Reviews and Meta-Analyses-guided systematic review. Several aspects of investigation design and conduct were analyzed: genetic analysis for propensity to placebo response, equipoise of informed consent process, geography of trial subjects, percentage of eligible subjects willing to be randomized, changes from protocol publication to results publication, and perioperative complications. RESULTS: Seven sham surgery-controlled trials (845 subjects [370 knees, 449 shoulders, 26 elbows]; 5 from Europe, 1 from North America, and 1 from Australia; all superiority model, efficacy design) were analyzed. There were consistent methodologic deficiencies across studies. No studies reported genetic analysis of susceptibility to placebo response. Three studies (43%) were underpowered. Crossover rates ranged from 8% to 36%, which led to un-blinding in up to 100% of subjects. There were low enrollment rates of eligible subjects (up to 57% refused randomization). Follow-up was short term (2 years or less in all but one study). Complication rates ranged from 0% to 12.5%, with complications occurring in both groups (no significant difference between groups in any study). CONCLUSIONS: Randomized sham-controlled studies in orthopaedic sports medicine have significant methodologic deficiencies that may invalidate their conclusions. Randomized trial design (with or without placebo control) may be optimized through the inclusion of per-protocol analysis, blinding index, equivalence or noninferiority trial design, and a nontreatment group. LEVEL OF EVIDENCE: Level II Systematic Review of Level II studies.

Polyploidy road to therapy-induced cellular senescence and escape.

Therapy-induced cellular senescence (TCS), characterized by prolonged cell cycle arrest, is an in vivo response of human cancers to chemotherapy and radiation. Unfortunately, TCS is reversible for a subset of senescent cells, leading to cellular reproliferation and ultimately tumor progression. This invariable consequence of TCS recapitulates the clinical treatment experience of patients with advanced cancer. We report the findings of a clinicopathological study in patients with locally advanced non-small cell lung cancer demonstrating that marker of in vivo TCS following neoadjuvant therapy prognosticate adverse clinical outcome. In our efforts to elucidate key molecular pathways underlying TCS and cell cycle escape, we have previously shown that the deregulation of mitotic kinase Cdk1 and its downstream effectors are important mediators of survival and cell cycle reentry. We now report that aberrant expression of Cdk1 interferes with apoptosis and promotes the formation of polyploid senescent cells during TCS. These polyploid senescent cells represent important transition states through which escape preferentially occurs. The Cdk1 pathway is in part modulated differentially by p21 and p27 two members of the KIP cyclin-dependent kinase inhibitor family during TCS. Altogether, these studies underscore the importance of TCS in cancer therapeutics.

Rat hepatocyte culture model of macrosteatosis: effect of macrosteatosis induction and reversal on viability and liver-specific function.

BACKGROUND & AIMS: A common cause of liver donor ineligibility is macrosteatosis. Recovery of such livers could enhance donor availability. Living donor studies have shown diet-induced reduction of macrosteatosis enables transplantation. However, cadaveric liver macrosteatotic reduction must be performed ex vivo within hours. Towards this goal, we investigated the effect of accelerated macrosteatosis reduction on hepatocyte viability and function using a novel system of macrosteatotic hepatocytes. METHODS: Hepatocytes isolated from lean Zucker rats were cultured in a collagen sandwich, incubated for 6 days in fatty acid-supplemented medium to induce steatosis, and then switched for 2 days to medium supplemented with lipid metabolism promoting agents. Intracellular lipid droplet size distribution and triglyceride, viability, albumin and urea secretion, and bile canalicular function were measured. RESULTS: Fatty acid-supplemented medium induced microsteatosis in 3 days and macrosteatosis in 6 days, the latter evidenced by large lipid droplets dislocating the nucleus to the cell periphery. Macrosteatosis significantly impaired all functions tested. Macrosteatosis decreased upon returning hepatocytes to standard medium, and the rate of decrease was 4-fold faster with supplemented agents, yielding 80% reduction in 2 days. Viability of macrosteatosis reduced hepatocytes was similar to control lean cells. Accelerated macrosteatotic reduction led to faster recovery of urea secretion and bile canalicular function, but not of albumin secretion. CONCLUSIONS: Macrosteatosis reversibly decreases hepatocyte function and supplementary agents accelerate macrosteatosis reduction and some functional restoration with no effect on viability. This in vitro model may be useful to screen agents for macrosteatotic reduction in livers before transplantation.

Self-supervised maize kernel classification and segmentation for embryo identification.

Introduction: Computer vision and deep learning (DL) techniques have succeeded in a wide range of diverse fields. Recently, these techniques have been successfully deployed in plant science applications to address food security, productivity, and environmental sustainability problems for a growing global population. However, training these DL models often necessitates the large-scale manual annotation of data which frequently becomes a tedious and time-and-resource- intensive process. Recent advances in self-supervised learning (SSL) methods have proven instrumental in overcoming these obstacles, using purely unlabeled datasets to pre-train DL models. Methods: Here, we implement the popular self-supervised contrastive learning methods of NNCLR Nearest neighbor Contrastive Learning of visual Representations) and SimCLR (Simple framework for Contrastive Learning of visual Representations) for the classification of spatial orientation and segmentation of embryos of maize kernels. Maize kernels are imaged using a commercial high-throughput imaging system. This image data is often used in multiple downstream applications across both production and breeding applications, for instance, sorting for oil content based on segmenting and quantifying the scutellum's size and for classifying haploid and diploid kernels. Results and discussion: We show that in both classification and segmentation problems, SSL techniques outperform their purely supervised transfer learning-based counterparts and are significantly more annotation efficient. Additionally, we show that a single SSL pre-trained model can be efficiently finetuned for both classification and segmentation, indicating good transferability across multiple downstream applications. Segmentation models with SSL-pretrained backbones produce DICE similarity coefficients of 0.81, higher than the 0.78 and 0.73 of those with ImageNet-pretrained and randomly initialized backbones, respectively. We observe that finetuning classification and segmentation models on as little as 1% annotation produces competitive results. These results show SSL provides a meaningful step forward in data efficiency with agricultural deep learning and computer vision.

Shear wave elastography of the ulnar collateral ligament in division IA pitchers across a competitive collegiate season.

Background: The ulnar collateral ligament (UCL) is a commonly injured elbow stabilizer during throwing. Shear wave elastography (SWE) is a technique that may reveal structural changes in the UCL that are indicative of ligament health and injury risk. The purpose of this study was to assess preseason and inseason shear wave velocity (SWV) in the UCL of collegiate pitchers and to asses repeatability of this measurement technique in healthy volunteers. Methods: Seventeen collegiate baseball pitchers and 11 sex-matched volunteers were recruited. Two-dimensional SWE of the UCL was performed by a single radiologist. In pitchers, SWV was measured at the proximal, midsubstance, and distal UCL for dominant and nondominant elbows preseason, midseason, and postseason, and Kerlan-Jobe Orthopaedic Clinic (KJOC) Shoulder and Elbow questionnaire scores were recorded. In volunteers, SWV was measured at UCL midsubstance in dominant elbows at 3 separate occasions over 1 week. An independent samples t-test was used to compare preseason midsubstance measures between pitchers and the healthy volunteers. A mixed-model analysis of covariance (covaried on preseason measures) was used to compare SWV measures at the preseason, midseason, and postseason time points. A similar generalized linear model for nonparametric data was used to compare KJOC scores. Type-I error was set at P < .05. Results: Mean preseason midsubstance dominant arm UCL SWV did not significantly differ between the pitchers (5.40 ± 1.65 m/s) compared to the healthy volunteers (4.35 ± 1.45 m/s). For inseason measures among the pitchers, a decrease in midsubstance (-1.17 ± 0.99 m/s, P = .021) and proximal (-1.55 ± 0.91 m/s, P = .001) SWV was observed at midseason compared to preseason. The proximal measure was also observed to be significantly lower than the nondominant arm (-1.97 ± 0.95 m/s, P < .001). Proximal SWV remained reduced relative to the preseason and the postseason mark (-1.13 ± 0.91 m/s, P = .015). KJOC scores decreased at midseason compared to preseason (P = .003) but then increased to a similar preseason value at the postseason measurement (preseason = 92 ± 3, midseason = 87 ± 3, postseason = 91 ± 3). The repeatability coefficient of SWE in the volunteer cohort was 1.98 m/s. Conclusion: Decreased SWV in the proximal and midsubstance of the dominant arm UCL at midseason suggests structural changes indicative of increasing laxity or 'softening' of the UCL. Associated decline in KJOC scores suggests that these changes are associated with functional decline. Future studies with more frequent sampling would be invaluable to further explore this observation and its significance for predicting and managing UCL injury risk.

Anterior versus posterior spinal fusion for Lenke type 5 adolescent idiopathic scoliosis: a systematic review and meta-analysis of comparative studies.

PURPOSE: To review and compare clinical and radiologic outcomes between anterior spinal fusion (ASF) and posterior spinal fusion (PSF) for the treatment of Lenke type 5 adolescent idiopathic scoliosis (AIS). METHODS: A systematic review was performed according to Preferred reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. All level I-III evidence studies investigating the clinical and radiologic outcomes of ASF and PSF for the treatment of Lenke type 5 AIS were included. RESULTS: Nine studies (285 ASF patients, 298 PSF patients) were included. ASF was associated with a significantly lower number of levels fused compared with PSF (p < 0.01) with similar immediate and long-term coronal deformity correction (p = 0.16; p = 0.12, respectively). PSF achieved a better correction of thoracic hypokyphosis in one study and lumbar hypolordosis in three studies. PSF was associated with a significant shorter length of stay (LOS) compared with ASF (p < 0.01). One long-term study demonstrated a significantly higher rate of proximal junctional kyphosis (PJK) with PSF compared with ASF. There were no significant differences in major complication or re-operation rates. CONCLUSION: For the treatment of Lenke type 5 AIS, there is moderate evidence to suggest that ASF requires a lower number of instrumented levels to achieve similar immediate and long-term coronal deformity correction compared with PSF. There is some evidence to suggest that PSF may achieve better thoracic and lumbar sagittal deformity correction compared with ASF. There is some evidence to suggest a higher incidence of PJK at long-term follow-up with PSF compared with ASF. ASF is associated with a longer post-operative LOS compared with PSF.

Healthy Hip Joints Have Different Macroscopic and Microscopic Capsular Nerve Architecture Compared With Hips With Osteoarthritis, Femoroacetabular Impingement Syndrome, and Developmental Dysplasia of the Hip: A Systematic Review.

PURPOSE: To perform a systematic review to identify macroscopic and microscopic patterns and differences in hip capsule innervation between normal hips and hips with osteoarthritis (OA), femoroacetabular impingement (FAI) syndrome, and developmental dysplasia of the hip (DDH). METHODS: A systematic review was performed using Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Multiple databases were searched for both clinical and basic science laboratory studies on hip capsule innervation. Non-innervation capsule and non-human animal studies were excluded. Macroscopic and microscopic differences in capsular innervation between normal hips, and hips with OA, FAI, and DDH were analyzed. Methodological quality assessment of all studies included in this review was completed using the Methodological Index for Non-randomized Studies. RESULTS: Ten articles were analyzed (263 specimens; 211 patients, 52 cadavers; mean Methodological Index for Non-randomized Studies 10/16). The hip capsule is innervated by the sciatic and superior gluteal nerves posterosuperiorly, nerve to quadratus femoris and inferior gluteal nerve posteroinferiorly, and femoral and obturator nerves anteriorly. The anterior-superior capsule between 1:00 and 2:30 o'clock on a right hip is a safe internervous zone. The superolateral capsule has the greatest density of mechanoreceptors and sensory fibers. OA is associated with a greater expression of nerve fibers compared with normal hips but does not correlate with pain or disability. No significant differences were found in nerve fiber expression among patients with DDH, FAI, or normal hips. A negative correlation is seen with aging and pain fiber expression. CONCLUSIONS: The hip capsule has a complex macroscopic and microscopic innervation pattern with varying nerve fiber expression from at least 6 separate peripheral nerves. OA is associated with a greater expression of nerve fibers, although nerve fiber expression does not correlate with painful pathology. LEVEL OF EVIDENCE: IV, Systematic review of level I-IV studies.

Double Tension Slide Technique as a Novel Repair for Distal Biceps Tendon Tear: A Biomechanical Evaluation.

Background A comparative biomechanical analysis of two distal biceps tendon repair techniques was performed: a single suture tension slide technique (TST) and two suture double tension slide (DTS) technique. Methodology Ten matched pairs of fresh frozen human cadaveric elbows (20 elbows) were randomly separated into two cohorts for distal biceps tendon repair. One cohort underwent the TST, and the other underwent the DTS technique. The tendon was preconditioned with cyclic loading from 0° to 90° at 0.5 Hz for 3,600 cycles with a 50 N load. The specimens were then loaded to failure at a rate of 1 mm/s. The difference in the load to failure between the groups was analyzed using the Student's t test. The mode of failure was compared between groups using the chi-square test. All p-values were reported with significance set at p < 0.05. Results Overall, 77.8% of the included matched pairs demonstrated greater load to failure in the DTS group. The mean load to failure in the DTS group was 383.3 ± 149.3 N compared to 275.8 ± 98.1 N in the TST group (p = 0.13). The DTS specimens failed at the tendon (5/9), suture (3/9), and bone (1/9). The TST specimens failed at the tendon (4/9) and suture (5/9) only. There was no significant difference in failure type between groups (p = 0.76). Conclusions DTS demonstrates a similar to greater load to failure compared to TST with a trend towards statistical significance. The redundancy provided by the second suture has an inherent advantage without compromising the biomechanical testing.

Interrater and Intrarater Reliability of the Beighton Score: A Systematic Review.

BACKGROUND: The Beighton score is commonly used to assess the degree of hypermobility in patients with hypermobility spectrum disorder. Since proper diagnosis and treatment in this challenging patient population require valid, reliable, and responsive clinical assessments such as the Beighton score, studies must properly evaluate efficacy and effectiveness. PURPOSE: To succinctly present a systematic review to determine the inter- and intrarater reliability of the Beighton score and the methodological quality of all analyzed studies for use in clinical applications. STUDY DESIGN: Systematic review; Level of evidence, 3. METHODS: A systematic review of the MEDLINE, Embase, CINAHL, and SPORTDiscus databases was performed. Studies that measured inter- or intrarater reliability of the Beighton score in humans with and without hypermobility were included. Non-English, animal, cadaveric, level 5 evidence, and studies utilizing the Beighton score self-assessment version were excluded. Data were extracted to compare scoring methods, population characteristics, and measurements of inter- and intrarater reliability. Risk of bias was assessed with the COSMIN (Consensus-Based Standards for the Selection of Health Measurement Instruments) 2017 checklist. RESULTS: Twenty-four studies were analyzed (1333 patients; mean ± SD age, 28.19 ± 17.34 years [range, 4-71 years]; 640 females, 594 males, 273 unknown sex). Of the 24 studies, 18 reported raters were health care professionals or health care professional students. For interrater reliability, 5 of 8 (62.5%) intraclass correlation coefficients and 12 of 19 (63.2%) kappa values were substantial to almost perfect. Intrarater reliability was reported as excellent in all studies utilizing intraclass correlation coefficients, and 3 of the 7 articles using kappa values reported almost perfect values. Utilizing the COSMIN criteria, we determined that 1 study met "very good" criteria, 7 met "adequate," 15 met "doubtful," and 1 met "inadequate" for overall risk of bias in the reliability domain. CONCLUSION: The Beighton score is a highly reliable clinical tool that shows substantial to excellent inter- and intrarater reliability when used by raters of variable backgrounds and experience levels. While individual components of risk of bias among studies demonstrated large discrepancy, most of the items were adequate to very good.

Poly-SUMO-2/3 chain modification of Nuf2 facilitates CENP-E kinetochore localization and chromosome congression during mitosis.

SUMO modification is required for the kinetochore localization of the kinesin-like motor protein CENP-E, which subsequently mediates the alignment of chromosomes to the spindle equator during mitosis. However, the underlying mechanisms by which sumoylation regulates CENP-E kinetochore localization are still unclear. In this study, we first elucidate that the kinetochore protein Nuf2 is not only required for CENP-E kinetochore localization but also preferentially modified by poly-SUMO-2/3 chains. In addition, poly-SUMO-2/3 modification of Nuf2 is significantly upregulated during mitosis, which is temporally correlated to the kinetochore localization of CENP-E during mitosis. We further show that the mitotic defects in CENP-E kinetochore localization and chromosome congression caused by global inhibition of sumoylation can be rescued by expressing a fusion protein between Nuf2 and the SUMO-conjugating enzyme Ubc9 for stimulating Nuf2 SUMO-2/3 modification. Moreover, the expression of another fusion protein between Nuf2 and three SUMO-2 moieties (SUMO-2 trimer), which mimics the trimeric SUMO-2/3 chain modification of Nuf2, can also rescue the mitotic defects due to global inhibition of sumoylation. Conversely, expressing the other forms of Nuf2-SUMO fusion proteins, which imitate Nuf2 modifications by SUMO-2/3 monomer, SUMO-2/3 dimer, and SUMO-1 trimer, respectively, cannot rescue the same mitotic defects. Lastly, compared to Nuf2, the fusion protein simulating the trimeric SUMO-2 chain-modified Nuf2 exhibits a significantly higher binding affinity to CENP-E wild type containing a functional SUMO-interacting motif (SIM) but not the CENP-E SIM mutant. Hence, our results support a model that poly-SUMO-2/3 chain modification of Nuf2 facilitates CENP-E kinetochore localization and chromosome congression during mitosis.Abbreviations: CENP-E, centromere-associated protein E; SUMO, small ubiquitin-related modifier; SIM, SUMO-interacting motif.

Sarcopenia predicts perioperative adverse events following complex revision surgery for the thoracolumbar spine.

BACKGROUND CONTEXT: Sarcopenia measured by psoas muscle index (PMI) has been shown to predict perioperative mortality and adverse events (AEs) after various surgical procedures. However, this relationship has not been studied in complex revision thoracolumbar spine surgery. PURPOSE: This study aimed to determine the relationship between sarcopenia and perioperative AEs among patients undergoing complex revision thoracolumbar spine surgery. STUDY DESIGN: Retrospective cohort study PATIENT SAMPLE: A retrospective analysis was performed at a single institution between May 2016 and February 2020 of patients undergoing complex revision thoracolumbar spine surgery by three board certified fellowship-trained orthopaedic spine surgeons. OUTCOME MEASURES: Perioperative adverse events including postoperative anemia requiring transfusion, cardiac complication, sepsis, wound complication, delirium, intra-operative dural tear, acute kidney injury, pneumonia, urinary tract infection, urinary retention, epidural hematoma, and deep vein thrombosis. Secondary outcome measures were 30-day readmission rates, 30-day re-operation rates, in-hospital mortality rates, discharge disposition, and postoperative length of stay (LOS). METHODS: Sarcopenia was analyzed using PMI, calculated at the L3 vertebral body measured on preoperative magnetic resonance imaging (MRI) or computed tomography (CT) normalized to height2 (mm2/m2). Receiver operating characteristic (ROC) curve analysis and Youden index were used to determine gender-specific PMI cut-off values for predicting perioperative AEs. Sarcopenia was defined as PMI below the cut-off values. Complex revision surgery was defined as Spine Surgical Invasiveness Index >10. RESULTS: A total of 114 consecutive patients were included in the study. ROC curve analysis demonstrated PMI <500 mm2/m2 for males and <412 mm2/m2 for females as predictors for perioperative AEs. 49 patients were in the sarcopenia cohort and 65 patients in the nonsarcopenia cohort. The sarcopenia group had higher overall perioperative AEs (75.5% vs 27.7%, p<.001) and individual AEs including: postoperative anemia requiring transfusion, wound complication, delirium, acute kidney injury, pneumonia, urinary tract infection, and deep vein thrombosis. The sarcopenia group had higher 30-day reoperation rate (14.3% vs 3.1%, p=.037), 30-day readmission rate (16.3% vs 3.1%, p=.018), rate of discharge to a facility (83.7% vs 50.8%, p<.001), and longer length of stay (LOS) (7.3±4.2 days vs 5.6±3.5 days, p=.023). CONCLUSIONS: Sarcopenia measured by PMI is associated with higher perioperative AEs, 30-day readmission rates, 30-day reoperation rates, rate of discharge to a facility, and longer LOS among patients undergoing complex revision thoracolumbar spine surgery.

Perceptions of Polymethyl Methacrylate Cement Exposure Among Female Orthopaedic Surgeons.

The medical field has long believed that polymethyl methacrylate (PMMA) vapor is dangerous to a growing fetus, and therefore, women who are pregnant should avoid exposure to it. Symptoms of vapor exposure include eye irritation, coughing, respiratory tract irritation, and irritation of exposed mucous membranes. The purpose of this study is to investigate the perceptions of PMMA cement exposure during pregnancy in female orthopaedic surgeons because it influences (1) the currently held beliefs and practices and (2) clinical and career choices. Methods: A 23-question survey was distributed via e-mail to all active members of the Ruth Jackson Orthopaedic Society and the "Women in Orthopaedics" private Facebook group. Questions consisted of the level of training, current usage of PMMA, previous exposure during pregnancy and/or breastfeeding, and beliefs regarding current or future willingness of exposure during pregnancy/breastfeeding. Results: PMMA training was found to have a positive correlation with those who remained in the operating room while pregnant or would do so in the future. Overall responses found that 41.7% would leave the room in the future if PMMA were being used while they were pregnant, with 24.7% leaving if they were breastfeeding. If they were the primary surgeon, 23.7% stated that they would leave and 8.4% stated that PMMA exposure during pregnancy factored into which subspecialty they chose. Conclusion: This survey demonstrates a lack of consensus among practicing female orthopaedic surgeons regarding the risks posed by remaining in a room during pregnancy and breastfeeding while PMMA is in use. Currently held beliefs and education practices should be examined to determine if they match the available literature.

Is there a relationship between femoral neck-shaft angle and ischiofemoral impingement in patients with hip pain?

Ischiofemoral impingement (IFI) is a cause of deep gluteal space syndrome. The prevalence of radiographic findings in patients with hip pain is unknown. To assess if there is a correlation between femoral neck-shaft angle (NSA) and the distance of the ischiofemoral space (IFS) and quadratus femoris space (QFS) and to determine the prevalence of quadratus femoris (QF) edema in patients with hip pain. A retrospective case series was conducted involving 100 consecutive hip or pelvis magnetic resonance imaging scans on patients presenting with hip pain. NSA, IFS and QFS distances were measured and presence of QF edema was noted. Analysis of the groups (QF edema vs no edema) was performed using two-tailed t-test and Pearson correlation. There were 18 hips in the edema group (mean age 51.11 years ± 10.5) and 82 hips in the non-edema group (mean age 40.79 years ± 15.9). Within the edema group, there was a moderate positive correlation between NSA and QFS (r = 0.498, P = 0.036) and a weak positive correlation between NSA and IFI (0.312, P = 0.208). The prevalence of QF edema in this study was 18% with only 28% of those subjects having clinical symptoms of IFI. Patients with QF edema had significantly narrower QFS and IFS distances (P < 0.001). The prevalence of QF edema is 18% in a consecutive sample of adults with hip pain. In patients with QF edema, only 28% have symptoms of IFI. In patients with QF edema, there was a moderate positive correlation between NSA and QFS.

Is the Iliopsoas a Femoral Head Stabilizer? A Systematic Review.

PURPOSE: To perform a systematic review of biomechanical and clinical studies to determine whether the iliopsoas is a femoral head stabilizer. METHODS: A systematic review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Inclusion criteria were any human clinical (Levels I-IV evidence) or laboratory studies that investigated the role of the iliopsoas as a stabilizer of the hip. Exclusion criteria included studies that investigated patients undergoing spine surgery or those with a total hip arthroplasty or hip hemiarthroplasty. Study methodologic quality for clinical-outcomes studies were analyzed using the Modified Coleman Methodology Score. Because of the heterogeneity in the participants and interventions, no quantitative assimilative meta-analysis was performed. RESULTS: Eight articles were analyzed (3 biomechanical [35 cadavers and 18 healthy subjects]; 5 clinical outcomes studies [537 subjects, 207 arthroscopic iliopsoas tenotomies]). Two in vivo biomechanical studies identified the iliopsoas as an anterior hip stabilizer. One cadaveric study identified the iliopsoas as a femoral head stabilizer at 0o-15o of hip flexion. Two clinical studies demonstrated the role of the iliopsoas as a dynamic hip stabilizer, particularly in patients with increased femoral version (greater than 15˚-25˚). Two studies reported cases of atraumatic anterior hip dislocations after arthroscopic iliopsoas tenotomies. CONCLUSIONS: Evidence from biomechanical and clinical studies may suggest that the iliopsoas is a dynamic anterior femoral head stabilizer. LEVEL OF EVIDENCE: Level IV, systematic review of Level III and IV plus biomechanical studies.

Distal Biceps Tendon Repair Using a Double Tension Slide Technique.

Distal biceps tendon ruptures are thought to be secondary to an acute forceful eccentric load on a degenerative tendon. Nonoperative treatment following rupture leads to significantly decreased forearm supination and elbow flexion strength. There are several techniques described in the literature for repair. This article describes, with video illustration, distal biceps tendon repair using a double tension slide technique with 2 No. 2 high-tension nonabsorbable composite sutures.

An Injury Prevention Program for Professional Ballet: A Randomized Controlled Investigation.

BACKGROUND: Few investigations have examined dance-specific injury prevention programs (IPPs), and no published randomized controlled trials are available that evaluate IPPs for dance. HYPOTHESIS: The implementation of an IPP will significantly reduce the risk of injury in professional ballet dancers. STUDY DESIGN: Randomized controlled trial; Level of evidence, 2. METHODS: A randomized controlled trial was designed that entailed a superiority model for the intervention group. All professional dancers from a single ballet company were eligible to participate. Randomization and allocation were performed before the start of the season. The control group practiced and performed without change to preexisting standard operating practice. The IPP group was instructed to perform a 30-minute exercise program 3 times per week over the 52-week study period. Injuries were recorded. Standard continuous and categorical data comparisons and correlations were used. Cox proportional hazards regression models for recurrent failures were used wherein the hazard ratio indicates the relative likelihood of injury in the control versus intervention groups. RESULTS: Of the 52 eligible dancers, 75% (n = 39) participated. Of these 39 dancers, 19 (9 males, 10 females; mean age, 26.6 ± 4.0 years) were randomized to the control group and 20 (11 males, 9 females; mean age, 25.1 ± 5.1 years) to the IPP group. No significant (P > .05) difference was found in baseline demographics between groups. A total of 116 injuries were recorded for the entire study population (49 IPP; 67 control). Traumatic and chronic injuries accounted for 54% and 46% of injuries, respectively. The injury rate was 82% less (IPP hazard ratio, 0.18; z = -2.29; P = .022) in the IPP group after adjustment for confounding variables, and time between injuries was 45% longer (IPP hazard ratio, 0.55; z = -2.20; P = .028) than for controls. CONCLUSION: The present study is the first prospective randomized controlled investigation of an IPP for professional ballet. The results showed an 82% decrease in injury rate for the intervention group and an extended period from previous injury to subsequent injury. REGISTRATION: NCT04110002 (ClinicalTrials.gov identifier).

Acute Physiologic Effects of Performing Yoga in The Heat on Energy Expenditure, Range of Motion, and Inflammatory Biomarkers.

Performing yoga in a heated environment (HY) is a popular exercise mode purported to improve range of motion (ROM), body composition, and aerobic fitness. The purpose of this investigation was to compare a session of HY to room temperature yoga (RTY) with regards to ROM, oxygen consumption, caloric expenditure, and biomarkers of acute stress and inflammation. Sixteen experienced yoga practitioners (F14, M2; 40 ± 11yr; 22.6 ± 1.8 kg/m2) completed a 1-hour standardized Bikram sequence in HY (105°F, 40°C) and RTY (74°F, 23.3°C) conditions (order of conditions randomized, humidity standardized at 40%). Intra-exercise metabolic gas exchange and heart rate (HR) was monitored using a metabolic cart. ROM measures were taken pre and post-exercise at the elbow, shoulder, hip, and knee. Cytokines interleukin 6,10 (IL-6, IL-10) and tumor-necrosis-factor alpha (TNF-α) were analyzed from blood samples collected pre- and 30-minutes post-exercise. Intra-exercise metabolic gas exchange and heart rate (HR) was monitored using a metabolic cart. Both bouts elicited similar acute changes in ROM although HY elicited a greater increase in hip abduction (RTYΔ° = 2.3 ± 1.3|HYΔ° = 6.6 ± 1.5; p < 0.05). Mean VO2, peak VO2, %VO2max, HR, and kcal expenditure did not differ between conditions. RER was lower during the HY (RTY = 0.95 ± 0.02| HY = 0.89 ± 0.02; p < 0.05) with a concomitant elevation in fat oxidation (RTY = 0.05 ± 0.01|HY = 0.09 ± 0.01, g·min-1; p < 0.05) and decrease in carbohydrate oxidation (RTY = 0.51 ± 0.04|HY = 0.44 ± 0.03, g·min-1; p < 0.05). Serum IL-6 was increased (15.5 ± 8.0-fold) following HY only (p < 0.05). HY does not significantly elevate aerobic energy cost compared to RTY but may acutely increase fat substrate utilization and hip ROM. Future studies remain needed to establish dose-response relationships for including HY or RTY into well-rounded fitness programs.