Increased neurotoxicity of high-density lipoprotein secreted from murine reactive astrocytes deficient in a peroxisomal very-long-chain fatty acid transporter Abcd1.

X-linked adrenoleukodystrophy (X-ALD) is a genetic neurodegenerative disorder caused by pathogenic variants in ABCD1, resulting in the accumulation of very-long-chain fatty acids (VLCFAs) in tissues. The etiology of X-ALD is unclear. Activated astrocytes play a pathological role in X-ALD. Recently, reactive astrocytes have been shown to induce neuronal cell death via saturated lipids in high-density lipoprotein (HDL), although how HDL from reactive astrocytes exhibits neurotoxic effects has yet to be determined. In this study, we obtained astrocytes from wild-type and Abcd1-deficient mice. HDL was purified from the culture supernatant of astrocytes, and the effect of HDL on neurons was evaluated in vitro. To our knowledge, this study shows for the first time that HDL obtained from Abcd1-deficient reactive astrocytes induces a significantly higher level of lactate dehydrogenase (LDH) release, a marker of cell damage, from mouse primary cortical neurons as compared to HDL from wild-type reactive astrocytes. Notably, HDL from Abcd1-deficient astrocytes contained significantly high amounts of VLCFA-containing phosphatidylcholine (PC) and LysoPC. Activation of Abcd1-deficient astrocytes led to the production of HDL containing decreased amounts of PC with arachidonic acid in sn-2 acyl moieties and increased amounts of LysoPC, presumably through cytosolic phospholipase A2 α upregulation. These results suggest that compositional changes in PC and LysoPC in HDL, due to Abcd1 deficiency and astrocyte activation, may contribute to neuronal damage. Our findings provide novel insights into central nervous system pathology in X-ALD.

Physical Therapy May Not Be Successful for Patients With Cam-Type Femoroacetabular Impingement Syndrome and May Result in Insufficient Hip Range of Motion When Femoral Anteversion Is Less Than 16° and α-Angle Is Greater Than 65°.

PURPOSE: To identify factors associated with insufficient range of motion (ROM) improvement after the posterior pelvic tilt change in cam-type femoroacetabular impingement syndrome. METHODS: Preoperative computed tomography images from 71 consecutive patients with femoroacetabular impingement syndrome treated with arthroscopic cam resection were evaluated. Using a dynamic computer simulation program, 3-dimensional models with a 10° posterior pelvic tilt from the supine functional pelvic plane (baseline) were created by computed tomography models. Patients were divided into 2 groups: those who experienced >10° (effective group) and ≤10° (ineffective group) improvements in internal rotation at 90° flexion after a 10° posterior pelvic tilt. Demographic characteristics; preoperative range of internal rotation at 90° flexion; and radiographic parameters, including Tönnis grade, lateral center-edge angle, acetabular roof obliquity angle, central acetabular anteversion, cranial acetabular anteversion, femoral anteversion, and α angle, were compared in the 2 groups. Univariate and multivariable logistic regression analyses were performed to evaluate factors associated with insufficient ROM improvement following a 10° posterior pelvic tilt. RESULTS: The 71 patients included 58 men and 13 women, of mean age 41.4 ± 14.6 years. Posterior pelvic tilt was effective in 13 hips and ineffective in 58. Univariate analysis showed that preoperative range of internal rotation at 90°flexion, femoral anteversion, and α angle differed significantly in the 2 groups. Multivariable analysis showed that femoral anteversion <16° (odds ratio 7.4; 95% confidence interval 1.6-35; P = .012) and α angle >65° (odds ratio 6.7; 95% confidence interval 1.2-37; P = .027) were significant factors associated with insufficient ROM improvement after posterior pelvic tilt. CONCLUSIONS: Physical therapy may not be successful for patients with cam-type femoroacetabular impingement syndrome and may result in insufficient hip ROM when femoral anteversion is less than 16° and α-angle is greater than 65°. CLINICAL RELEVANCE: Patients with a prominent cam-type deformity and lower anterior femoral anteversion are at high risk of clinical failure following improvement in pelvic mobility by conservative treatment alone and are likely to benefit from surgery for cam deformity.

Ultrasound-Guided Percutaneous Ultrasonic Tenotomy for Refractory Patellar Tendinopathy in High-Level Athletes: A Case Series.

OBJECTIVE: To elucidate the clinical outcomes and return-to-sport status of high-level athletes with refractory patellar tendinopathy treated with ultrasound-guided percutaneous ultrasonic tenotomy (PUT). DESIGN: Case series study. SETTING: Single orthopaedic clinic. PATIENTS: Five cases involving 8 knees from athletes (average age: 22 years, range: 17-30 years) who presented with refractory patellar tendinopathy and underwent PUT between 2022 and 2024. Conservative treatments had previously been attempted without sufficient pain relief or return to sports. INTERVENTIONS: All patients underwent ultrasound-guided PUT using the TX-2 device from Tenex Health. Jogging was resumed 1 month after surgery, and a return to competitive sports was permitted as early as 3 months postsurgery. MAIN OUTCOME MEASURES: Preoperative and postoperative Victorian Institute of Sport Assessment (VISA) scores and Numerical Rating Scale (NRS) scores for pain. Time to return to full training and competitive sports, and presence of postoperative infection signs. RESULTS: The VISA score significantly improved from a preoperative average of 43.1 to a postoperative average of 77.1 (P = 0.0004). The NRS significantly decreased from a preoperative average of 6.4 to a postoperative average of 2.8 (P = 0.0005). Four cases involving 6 knees fully returned to sports, with an average return time of 3 months and 19 days (range: 3 months to 4 months and 13 days). One case involving 2 knees did not show sufficient pain improvement and the patient could not return to sports. No signs of infection were observed in any case. CONCLUSIONS: PUT for refractory patellar tendinopathy in high-level athletes generally results in favorable treatment outcomes and successful return to sports. This study provides novel insights into the effectiveness of PUT for patellar tendinopathy in athletes, highlighting the need for future studies with larger sample sizes to validate these findings and explore factors associated with poor outcomes.

Does Augmented Reality-based Portable Navigation Improve the Accuracy of Cup Placement in THA Compared With Accelerometer-based Portable Navigation? A Randomized Controlled Trial.

BACKGROUND: Previous studies reported good outcomes of acetabular cup placement using portable navigation systems during THA. However, we are aware of no prospective studies comparing inexpensive portable navigation systems using augmented reality (AR) technology with accelerometer-based portable navigation systems in THA. QUESTIONS/PURPOSES: (1) Is the placement accuracy of the acetabular cup using the AR-based portable navigation system superior to that of an accelerometer-based portable navigation system? (2) Do the frequencies of surgical complications differ between the two groups? METHODS: We conducted a prospective, two-arm, parallel-group, randomized controlled trial involving patients scheduled for unilateral THA. Between August and December 2021, we treated 148 patients who had a diagnosis of osteoarthritis, idiopathic osteonecrosis, rheumatoid arthritis, or femoral neck fracture and were scheduled to undergo unilateral primary THA. Of these patients, 100% (148) were eligible, 90% (133) were approached for inclusion in the study, and 85% (126) were finally randomized into either the AR group (62 patients) or the accelerometer group (64 patients). An intention-to-treat analysis was performed, and there was no crossover between groups and no dropouts; all patients in both groups were included in the analysis. There were no differences in any key covariates, including age, sex, and BMI, between the two groups. All THAs were performed via the modified Watson-Jones approach with the patient in the lateral decubitus position. The primary outcome was the absolute difference between the cup placement angle displayed on the screen of the navigation system and that measured on postoperative radiographs. The secondary outcome was intraoperative or postoperative complications recorded during the study period for the two portable navigation systems. RESULTS: There were no differences between the AR and accelerometer groups in terms of the mean absolute difference in radiographic inclination angle (3° ± 2° versus 3° ± 2° [95% CI -1.2° to 0.3°]; p = 0.22). The mean absolute difference in radiographic anteversion angle displayed on the navigation screen during surgery compared with that measured on postoperative radiographs was smaller in the AR group than that in the accelerometer group (2° ± 2° versus 5° ± 4° [95% CI -4.2° to -2.0°]; p < 0.001). There were few complications in either group. In the AR group, there was one patient each with a surgical site infection, intraoperative fracture, distal deep vein thrombosis, and intraoperative pin loosening; in the accelerometer group, there was one patient each with an intraoperative fracture and intraoperative loosening of pins. CONCLUSION: Although the AR-based portable navigation system demonstrated slight improvements in radiographic anteversion of cup placement compared with the accelerometer-based portable navigation system in THA, whether those small differences will prove clinically important is unknown. Until or unless future studies demonstrate clinical advantages that patients can perceive that are associated with such small radiographic differences, because of the costs and the unquantified risks associated with novel devices, we recommend against the widespread use of these systems in clinical practice. LEVEL OF EVIDENCE: Level I, therapeutic study.

Femoral prosthesis alignment of augmented reality-assisted versus accelerometer-based navigation in total knee arthroplasty: A noninferiority analysis.

INTRODUCTION: The purpose of this study was to examine the comparative precision of the augmented reality (AR)-assisted navigation system and the accelerometer-based navigation system in total knee arthroplasty (TKA). MATERIALS AND METHODS: We performed noninferiority analysis in a retrospective cohort. The coronal alignment of femoral prosthesis was compared between 109 TKAs performed using the AR-assisted navigation system and 118 TKAs performed using the accelerometer-based navigation system. All femoral prostheses were planned to be positioned perpendicular to the mechanical axis of the femur. The primary outcome was the success rate of coronal alignment of the femoral prosthesis defined as alignment error relative to neutral alignment <3°. We calculated the noninferiority margin as 7%-points using the 95%-95 % method and also confirmed the validity of the noninferiority margin using the fixed margin method. Noninferiority would be shown if the lower boundary of the 95 % confidence interval (CI) for the between-group difference in percentage of the success rate was not less than 0.93 (i.e., 1.00 - 0.07). RESULTS: Treatment success was achieved in 104 of 109 patients (95.4 %) in the AR-assisted navigation group and 110 of 118 (93.2 %) in the accelerometer-based navigation group. The risk ratio of success between the AR-assisted navigation group versus accelerometer-based navigation group was 1.02 (95 % CI, 0.96 to 1.09): the CIs did not include the noninferiority margin of 0.93. CONCLUSION: The AR-assisted navigation system was noninferior to the accelerometer-based navigation system in terms of coronal alignment of the femoral prosthesis in TKA.

Assay for transposase-accessible chromatin with high-throughput sequencing reveals radioresistance-related genes in oral squamous cell carcinoma cells.

Radiotherapy is commonly used to treat oral squamous cell carcinoma (OSCC), and radioresistance is a critical factor resulting in poor outcomes. Several genes have been reported to be therapeutic targets for radioresistance; however, the involvement of chromatin accessibility in radioresistance has not been clarified in OSCC cells. Accordingly, in this study, we evaluated chromatin accessibility in radioresistant (HSC-3) and radiosensitive (KOSC-2) cells, identified from nine OSCC cell lines using clonogenic survival assays after irradiation. Chromatin accessibility in radioresistant OSCC cells was assessed using assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq). Gene expression was evaluated by quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) and immunoblot analysis. Viability was assessed by MTS assay. We found 1273 peaks (open chromatin regions by ATAC-seq) related to 8 Gy irradiation in HSC-3 but not KOSC-2 cells, among which 235 genes located around the chromatin open peaks were identified by ChIPpeakAnno analysis. Subsequently, 12 genes were selected as signal transduction-related genes by Gene Ontology analysis, and gene expression was confirmed by RT-qPCR. Among these genes, adenylate cyclase 2 (ADCY2) was significantly upregulated after treatment with irradiation in HSC-3 but not KOSC-2 cells. To further evaluate ADCY2 function in radioresistant cells, we performed ADCY2 knockdown by transfection of HSC-3 cells with small interfering RNA (siADCY2). Cell viability after irradiation was significantly decreased in siADCY2-transfected cells compared with that in control cells. These results suggested that ADCY2 expression was related to the open chromatin region in radioresistant OSCC cells and that ADCY2 may have therapeutic efficacy when used in combination with radiotherapy in patients with OSCC.

Detection of Characteristic Phosphatidylcholine Containing Very Long Chain Fatty Acids in Cerebrospinal Fluid from Patients with X-Linked Adrenoleukodystrophy.

X-linked Adrenoleukodystrophy (X-ALD) is a rare genetic neurological disorder caused by a mutation of the ABCD1 gene that encodes a peroxisomal ABC protein ABCD1. ABCD1 has a role in transporting very long chain fatty acid (VLCFA)-CoA into the peroxisome for ß-oxidation. ABCD1 dysfunction leads to reduced VLCFA ß-oxidation and in turn increased VLCFA levels in the plasma and the cells of all tissues; these increased plasma levels have been used to diagnose X-ALD. It has been reported that plasma VLCFA is not correlated with the severity and disease phenotype of X-ALD. Therefore, we cannot predict the disease progression by the plasma VLCFA level. Cerebrospinal fluid (CSF) is constantly produced by brain, and thus levels of lipids containing VLCFA in CSF might be informative in terms of assessing X-ALD pathology. LC-MS/MS-based analysis showed that phosphatidylcholine (PC) containing VLCFA signals, such as PC 40 : 0(24 : 0/16 : 0), PC 42 : 0(26 : 0/16 : 0), PC 44 : 4(24 : 0/20 : 4) and PC 46 : 4(26 : 0/20 : 4) were characteristically detected only in the CSF from patients with X- ALD. In the present study, we analyzed limited number of patient's CSF samples (2 patients with X-ALD) due to the limitations of the availability for CSF samples from this rare disease. However, our finding would offer helpful information for studying the disease progression biomarkers in X-ALD. To our knowledge, this is the first report of analyzing lipids containing VLCFA in CSF from patients with X-ALD.

Femoro-Epiphyseal Acetabular Roof (FEAR) Index and Anterior Acetabular Coverage Correlate With Labral Length in Developmental Dysplasia of the Hip.

PURPOSE: The aim of this study was to evaluate the association between labral length and radiographic parameters of lateral and anterior acetabular coverage and the femoro-epiphyseal acetabular roof (FEAR) index in patients with developmental dysplasia of the hip (DDH). METHODS: We retrospectively analyzed data from patients with DDH who visited our hip joint clinic for the first time due to hip symptoms. DDH presence was defined as a lateral center-edge angle (LCEA) of ≤25°. The labral lengths on the anterior and lateral sides were measured on central axial and central coronal slices of T1-weighted magnetic resonance imaging, respectively. The Pearson correlation coefficients (r) and simple linear regression analyses were performed to determine the association of the lateral and anterior labral lengths with the radiographic parameters, including the LCEA, acetabular roof obliquity, FEAR index, anterior wall index, and vertical center anterior angle. RESULTS: This study included 88 patients, with a mean age of 39.6 ± 11.8 years. There were 65 women and 23 men. The lateral and anterior labral lengths correlated with all parameters of dysplasia. Specifically, the lateral labral length had a strong positive correlation with the FEAR index (R = 0.65, P < .001). The anterior labral length had a strong negative correlation with the anterior wall index (R = -0.66, P < .001). CONCLUSIONS: The lateral labral length had a strong positive correlation with the FEAR index. Furthermore, the anterior labral length had a correlation with the anterior dysplasia. LEVEL OF EVIDENCE: Level III, retrospective cross-sectional study.

Metabolomic profiling of urine-derived extracellular vesicles from rat model of drug-induced acute kidney injury.

Extracellular vesicles (EVs) are lipid bilayer particles that are released by various cells and provide a real-time snapshot of the state of these cells in tissue in a noninvasive manner. EVs contain components, including mRNA, miRNAs, proteins, and metabolites. Therefore, EVs hold promise for the discovery of liquid biopsy-based biomarkers for disease diagnosis. In the present study, metabolome analysis of urine EVs in rats with kidney injury caused by cisplatin and puromycin aminonucleoside was performed using liquid chromatography/mass spectrometry to identify candidate biomarkers that reflect the type and extent of injury in drug-induced nephrotoxicity. A total of 396 metabolites were detected in urine EVs, of which 65 were identified as potential biomarkers in urine EVs of drug-induced nephrotoxicity. Pathway analysis revealed that these metabolites may reflect changes occurring within damaged cells during kidney injury, suggesting that metabolomics of urine EVs could be a useful informative tool.

Outcomes After Arthroscopic Osteochondroplasty for Femoroacetabular Impingement Secondary to Slipped Capital Femoral Epiphysis: A Systematic Review.

PURPOSE: To determine the efficacy of arthroscopic osteochondroplasty for patients with femoroacetabular impingement (FAI) secondary to slipped capital femoral epiphysis (SCFE). METHODS: A systematic review was performed based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using Embase, PubMed (Medline), and Cochrane Library up to November 1, 2019. Data including patient demographics, slip severity according to Southwick, outcomes, and complications were retrieved from eligible studies that reported a minimum 3-month follow-up of arthroscopic osteochondroplasty for FAI secondary to SCFE. Methodological Index for Non-Randomized Studies (MINORS) criteria was used to assess quality of studies. Heterogeneity and quality were evaluated using P values and the I2 statistic. RESULTS: Six studies (90 hips) were analyzed. The range of MINORS scores was 8 to 11. Most studies were level of evidence 4 (n = 4, 66.7%), with more men than women (n = 5, 83.3%). The ranges of age, body mass index, and follow-up length after surgery were 10 to 42 years, 17.5 to 32.3 kg/m2, and 3 to 56 months, respectively. The Modified Harris Hip Score (mHHS) was the most commonly used score to report on clinical outcomes (n = 2 studies, 28 hips) with a significant improvement following surgery. Three studies reported an improvement in internal rotation (IR) of the hip with a range of improvement of 17° to 32°, with low heterogeneity (I2 = 0% and P = .531). Five studies reported a significant correction of the α angle, with range of improvement of 19.9° to 37.3°. The range of postoperative α angle was 32° to 67°, and 3 studies achieved appropriate postoperative α angle (40° to 50°), with low heterogeneity (I2 = 8.4% and P = .336). The total number of complications was 8 (1 major complication) and there were 6 revisions, with low heterogeneity. CONCLUSION: Arthroscopic osteochondroplasty for FAI secondary to SCFE provides good short- to medium-term outcomes and improves IR of the hip, with the ability to potentially correct the α angle with a low rate of complications and revision. LEVEL OF EVIDENCE: IV, systematic review of level II to IV studies.

Prognosis of Incomplete Avulsion of the Proximal Hamstring Tendon Is Determined by the Avulsion Location of the Proximal Hamstring Tendon Footprint.

OBJECTIVE: To test the hypothesis that prognosis of incomplete avulsion of the proximal hamstring tendon would be worse whether avulsion location reached the proximal part of the conjoined tendon (CJ) footprint or not. DESIGN: Retrospective chart review. SETTING: Outpatient specialty clinic. PATIENTS: We reviewed 345 consecutive athletes with hamstring injury. INTERVENTIONS: Based on magnetic resonance imaging, incomplete avulsion of the proximal hamstring tendon was divided into 2 cases according to avulsion location without (cases A) or with (cases B) avulsion of the proximal part of the CJ footprint. OUTCOME MEASURES: We compared the time until return to play, subjective outcomes, and success rate of avoiding surgery between cases. RESULTS: Incomplete avulsion of the proximal hamstring tendon was detected in 47 athletes (13.6%). Thirty-four athletes were classified as cases A, and 13 as cases B. Forty-two athletes (89.4%) were followed up until return to play. The median time from pain onset to return to play was significantly longer in cases B than in cases A (B, 39.3 weeks; A, 8.0 weeks; P = 0.00015). Subjective outcomes at return to play were significantly poorer in cases B than in cases A (P = 0.00054). Success rate of avoiding surgery were significantly poorer in cases B (55%) than in cases A (100%) (P = 0.00062). CONCLUSIONS: Incomplete avulsion of the proximal hamstring tendon was observed in 13.6% of hamstring injuries. Return to play, subjective outcomes, and success rate of avoiding surgery were significantly poorer with avulsion of the proximal part of the CJ footprint.

The cleft sign may be an independent factor of magnetic resonance imaging findings associated with a delayed return-to-play time in athletes with groin pain.

PURPOSE: To investigate the prevalence of magnetic resonance imaging (MRI) findings and define prognostic factors of the return-to-play time in young athletes with groin pain. METHODS: A total of 1091 consecutive athletes were retrospectively screened; 651 athletes, aged 16-40 years, with pain in the groin regions were assessed using MRI. Of these athletes, 356 were included for analysing the time to return-to-play. Univariate and multiple linear regression analyses were used to determine the associations between the time to return-to-play (primary outcome variable) and the following variables: age, sex, body mass index, type of sports, Hip Sports Activity Scale, clear trauma history, and 12 MRI findings. RESULTS: Four MRI findings, including cleft sign, pubic bone marrow oedema of both the superior and inferior ramus, and central disc protrusion of the pubic symphysis, appeared together in more than 44% of the cases. The median time to return-to-play was 24.7 weeks for athletes with a cleft sign on MRI, which was significantly longer than the 11.9 weeks for athletes without the sign. The median time to return-to-play was 20.8 weeks for athletes with BMI > 24, which was significantly longer than the 13.6 weeks for athletes with BMI â‰¦ 24. In multiple linear regression analysis of 356 athletes, in whom hip-related groin pain was excluded, and who were followed-up until the return-to-play, the body mass index and cleft sign were the independent factors associated with a delayed return-to-play. In contrast, iliopsoas muscle strain and other muscle injuries were associated with a shorter return-to-play. CONCLUSIONS: Multiple MRI findings were present in almost half of all cases. Body mass index and the cleft sign were independently associated with a delayed return-to-play time in young athletes suffering from groin pain. LEVEL OF EVIDENCE: III.

Obesity is associated with less favorable outcomes following hip arthroscopic surgery: a systematic review and meta-analysis.

PURPOSE: The aim of this study was to systematically review the existing literature comparing the postoperative outcomes after following hip arthroscopy in obese and non-obese patients. METHODS: Studies comparing the outcomes following hip arthroscopy of obese and non-obese patients were systematically identified via a computer-assisted literature search of Pubmed (Medline), EMBASE, and Cochrane Library using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Studies comparing the outcome of hip arthroscopy in different body mass index (BMI) groups were included. Data including patient-reported outcome measures (PROMs), revision arthroscopy rate, conversion rate to total hip arthroplasty (THA), and complications were collected. The methodological index for non-randomized studies (MINORS) and Newcastle-Ottawa Scale (NOS) were used to assess the quality of each study quality. The effect of heterogeneity was quantified by calculating the I2 value. RESULTS: A total of eight studies were finally included in the qualitative analysis, and three studies of high quality involving 373 hips were included in the quantitative assessment. All the studies defined obesity as a BMI of ≥ 30 kg/m2. The modified Harris Hip Score and the Non-Arthritic Hip Score were 5.1 (95% CI 1.1-9.1) and 9.0 (95% CI 5.0-13.1) points lower, respectively, in the obese group than in the non-obese group. The pooled odds ratios were 1.2 (95% CI 0.5-2.7) for revision arthroscopy, 2.4 (95% CI 1.3-4.6) for conversion to THA, and 3.2 (95% CI 1.2-8.6 for complications in favor of the non-obese group. The heterogeneity was low in all outcome assessments (I2 0-18%). CONCLUSION: Obese patients had significantly lower PROMs than non-obese patients following hip arthroscopic surgery, and the THA conversion and complication rates were 2.4 times and 3.2 times higher, respectively. Understanding the effect of obesity on hip arthroscopy will allow appropriate surgical indications for surgery to be further refined and help obese patients to understand their individual risk profile. LEVEL OF EVIDENCE: Systematic review of Level III-IV studies, Level IV.

Anatomical variation of the Psoas Valley: a scoping review.

BACKGROUND: This scoping review aimed to investigate the literature on the anatomy of the psoas valley, an anterior depression on the acetabular rim, and propose a unified definition of the anatomical structure, describe its dimensions, anatomical variations and clinical implications. METHODS: A systematic computer search of EMBASE, PubMed and Cochrane for literature related to the psoas valley was undertaken using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Clinical outcome studies, prospective/retrospective case series, case reports and review articles that described the psoas valley and its synonyms were included. Studies on animals as well as book chapters were excluded. RESULTS: Of the 313 articles, the filtered literature search identified 14 papers describing the psoas valley and its synonyms such as iliopsoas notch, a notch between anterior inferior iliac spine and the iliopubic eminence, Psoas-U and anterior wall depression. Most of these were cross-sectional studies that mainly analyzed normal skeletal hips. In terms of anatomical variation, 4 different configurations of the anterior acetabular rim have been identified and it was found that the curved type was the most frequent while the straight type may be nonexistent. Additionally, the psoas valley tended to be deeper in males as compared with females. Several papers established the psoas valley, or Psoas-U in a consistent location at approximately 3 o'clock on the acetabular rim which may have implications with labral pathology. CONCLUSION: This review highlights the importance of the anatomy of the psoas valley which is a consistent bony landmark. The anatomy and the anatomical variations of the psoas valley need to be well-appreciated by surgeons involved in the management of young adults with hip pathology and also joint replacement surgeons to ensure appropriate seating of the acetabular component.

Hip Arthroscopy and Borderline Developmental Dysplasia of the Hip: A Systematic Review.

PURPOSE: To provide an up-to-date evidence-based review of hip arthroscopy for patients with borderline developmental dysplasia of the hip (BDDH). METHODS: Literature describing hip arthroscopy in patients with BDDH was systematically identified from PubMed, EMBASE, and Cochrane Library using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. All studies that involved BDDH and not just those reporting their clinical outcomes were included. Methodological Index for Non Randomized Studies criteria and Newcastle-Ottawa Scale were used to assess the quality of studies. The definition of BDDH, operative technique, correlation with labrum and/or cartilage lesions, outcome, and factors associated with poor outcome were collected and analyzed. RESULTS: Assessment of the articles yielded 28 studies involving 1502 hips that were included for final analysis. There were no studies with a high risk of bias. BDDH was defined as lateral center-edge angle of 20° to 25° in most studies. Hip arthroscopy for BDDH showed an improvement in the weighted mean postoperative modified Harris Hip Score, from 60.2 to 81.7, a relatively high rate of acquisition of minimal clinically important difference of 79.5% to 87%, and had 1.0% rate of complications. Eleven studies reported on all the patients undergoing a capsular plication. Four studies reported that BDDH was associated with cartilage damage on the femoral head. Age older than 35 or 42 years and ≥20° of femoral anteversion were reported as risk factors for poor outcomes. CONCLUSIONS: Hip arthroscopy for BDDH with capsular plication provides improvement in patient-reported outcome measures and a relatively high rate of acquisition of minimal clinically important difference with a low rate of complications in the shorter term. BDDH may be associated with cartilage damage on the femoral head. Female sex is a factor related to good outcomes, whereas older age, excessive femoral anteversion, and anterior undercoverage of acetabulum are risk factors related to poorer outcomes. LEVEL OF EVIDENCE: Level IV, systematic review of Level III to IV studies.

Post-operative pain control following arthroscopic rotator cuff repair: peri-articular injection versus interscalene brachial plexus block.

PURPOSE: To compare post-operative pain relief with peri-articular injection (PI) versus interscalene brachial plexus block (IBPB) after arthroscopic rotator cuff repair (ARCR) surgery. METHODS: We retrospectively reviewed 121 consecutive patients undergoing ARCR surgery divided into two groups: the PI group and the IBPB group. We compared complications and self-reported pain score measured using a Numerical Rating Scale (NRS) during the initial 24 hours after surgery. RESULTS: The NRS scores recorded in the recovery room (0), 0.5, and four hours post-operatively were higher in the PI group (n = 38) than the IBPB group (n = 52) (2.1 vs. 0.8, p = 0.014; 1.4 vs. 0.5, p = 0.0069; and 1.3 vs. 0.5, p = 0.012, respectively). However, the NRS scores recorded at 16, 20, and 24 hours post-operatively were lower in the PI group than in the IBPB group (1.4 vs. 3.1, p < 0.0001; 1.4 vs. 3.2, p < 0.0001; and 1.7 vs. 3.2, p = 0.00046, respectively). The incidences of post-operative nausea and temporary numbness in the upper arm were significantly lower in the PI group than in the IBPB group (7.9% vs. 33%, p = 0.0052; and 13% vs. 85%, p < 0.0001, respectively). CONCLUSIONS: Although IBPB provided superior pain control during the initial few hours after ARCR surgery, PI was superior from 16 to 24 hours post-operatively. The rates of side effects, such as nausea and temporary arm numbness, were also lower in the PI group than in the IBPB group.

Correlation of alpha angle between various radiographic projections and radial magnetic resonance imaging for cam deformity in femoral head-neck junction.

PURPOSE: Radial magnetic resonance imaging (MRI) along the axis of the femoral head neck is the gold standard for detection of cam deformity of the proximal femur. This study was performed to identify which plain radiographic projection was best correlated with radial MRI. METHODS: Five different plain radiographic projections and 18 slices of radial MRI were applied to 35 consecutive hips with groin pain and positive impingement sign. Alpha angles were measured to detect the asphericity of the femoral head-neck junction in all images. Radiographs were taken in anteroposterior pelvis, cross-table lateral, 90° Dunn, 45° Dunn and modified 45° Dunn views. Pearson's correlation coefficients were determined to assess the association between the alpha angle obtained from radial MRI and each radiographic technique. The sensitivity, specificity, positive and positive predictive values and accuracy of plain radiographic alpha angle measurements were assessed using a threshold alpha angle value of 50.5° for cam deformity. RESULTS: Pearson's correlation coefficients in the alpha angle values between MRI and plain radiographic projections were 0.45, 0.70, 0.62, 0.81 and 0.69 for the anteroposterior pelvis, cross-table lateral, 90° Dunn, 45° Dunn and modified 45° Dunn views, respectively. In terms of sensitivity and accuracy, the 45° Dunn view had the greatest values. CONCLUSIONS: Alpha angle of the 45° Dunn view was best correlated with that of radial MRI. The 45° Dunn view had better sensitivity and accuracy than other radiographic projections. The 45° Dunn view may be preferable for screening of cam deformity. LEVEL OF EVIDENCE: II.

Hiding and recovering electrons in a dimetallic endohedral fullerene: air-stable products from radical additions.

Fullerenyl radicals can be generated by addition of a free radical to a fullerene surface, by nucleophilic addition followed by one-electron oxidation, or by thermal dissociation of singly bonded fullerene dimers. However, fullerenyl radicals are usually very reactive and generally cannot be isolated. On the contrary, we have found that the reactions of the dimetallic endofullerenes, La2@Ih-C80 and La2@D5h-C80, with 3-chloro-5,6-diphenyltriazine resulted in mono-addition of the triazinyl radical to the fullerene cages to yield isolable fullerenyl radicals. The unusual stability of these fullerenyl radicals arises from the confinement of the unpaired electron to an internal, metal-metal bonding orbital. Accordingly, the fullerene cage protects the radical center from other reactive species. Furthermore, we demonstrate that the fullerenyl radical adduct of La2@Ih-C80 reacts with toluene to afford additional benzylation. Interestingly, the benzylated derivative is diamagnetic in solution, while it forms a paramagnetic dimer when crystallized.

Prognostic relevance of apparent diffusion coefficient obtained by diffusion-weighted MRI in pancreatic cancer.

BACKGROUND: Diffusion-weighted magnetic resonance imaging (DW-MRI) is utilized as a method of oncologic imaging for predicting treatment outcomes. This study explored the role of DW-MRI in the treatment of patients with resected pancreatic cancer by comparing apparent diffusion coefficient (ADC) values with clinicopathological findings and survival rates. MATERIALS AND METHODS: Records of 54 patients in whom DW-MRI at 1.5T was performed (b values: 0 and 1000 mm(2) /s) before macroscopically curative resection were analyzed. ADC values were then calculated and compared with clinicopathological factors including age, gender, serum carcinoembryonic antigen levels, serum carbohydrate antigen 19-9 levels, lymph node metastasis, primary tumoral location, size, differentiation, resectability, and pT stage. A survival analysis of clinicopathological factors and ADC values was performed using the Kaplan-Meier method, and the results were evaluated with the log-rank test. Prognostic significance was assessed using the Cox proportional hazard model. RESULTS: Significant associations were found between tumor differentiation and ADC values (P = 0.001). In a univariate analysis of overall survival, tumor differentiation (P = 0.037) and ADC values (P = 0.002) were identified as significant prognostic factors. However, age, gender, carcinoembryonic antigen levels, carbohydrate antigen 19-9 levels, lymph node metastasis, primary tumoral location, size, resectability, and pT stage were not associated with overall survival. In a multivariate analysis of overall survival, only ADC values were identified as significant prognostic factors (hazard ratio 2.293, 95% confidence interval 1.147-4.585, P = 0.019). CONCLUSION: ADC values were found to be associated with prognosis in patients with resected pancreatic cancer.

A comparison of conventional 3.0-Tesla nonenhanced magnetic resonance imaging and arthroscopic findings of the anteroinferior capsulolabral complex in patients with traumatic anterior shoulder instability.

Background: This study aimed to evaluate the association between specific, reproducible findings of an anteroinferior capsulolabral complex obtained using conventional 3.0-Tesla nonenhanced magnetic resonance imaging (MRI) and pathologic arthroscopic findings and to assess the confidence level of the findings. Methods: Of 125 cases of traumatic anterior instability surgery from January 2017 to November 2019, 66 patients (52 men, 14 women; 23.5 ± 7.9 year old) who underwent conventional 3.0-Tesla MRI at our hospital were reviewed. The following anteroinferior capsulolabral complex features were observed on the T2-star axial image: size difference of the labrum (swelling, diminished), difference in marginal and internal signals (irregularity), and capsule edema image (capsular thickening). We also reviewed fraying, flattening, cracking, and capsular hypertrophy as pathologic arthroscopic findings of the capsulolabral complex. These findings allowed for the simultaneous description of the MRI and arthroscopic evaluations. Three orthopedic surgeons and one radiologist measured the interobserver reliability. We investigated the correlation between the MRI and arthroscopic findings. Results: The interobserver reliability of MRI irregularities was low (κ = -0.16), whereas reliability was moderate (κ = 0.554-0.595) for swelling in 22 cases (33%), diminished in 34 cases (52%), and capsular thickness in 40 cases (59%). Labral detachment was found in 26 patients (39%) and fluid collection in 24 patients (36%). The agreement of MRI findings with arthroscopic findings was κ = 0.46 (95% confidence interval [CI]: 0.268-0.654) for swelling to fraying; κ = 0.42 (95% CI: 0.202-0.638) for swelling to capsular hypertrophy; and 0.46 (95% CI: 0.268-0.654) for flattening to diminished. Conclusion: The swelling and diminished findings of the anteroinferior capsulolabral complex on conventional MRI were moderately related to pathologic arthroscopic findings in patients with traumatic anterior shoulder instability. These findings contribute to achieving an accurate clinical diagnosis.