Enhanced expression of activity-regulated cytoskeleton-associated protein in the medial prefrontal cortex is involved in working memory performance.

Working memory (WM) is a cognitive function important for guiding the on-going or upcoming behavior. A memory-related protein Arc (activity-regulated cytoskeleton-associated protein) is implicated in long-term memory consolidation. Recent evidence further suggests the involvement of hippocampal Arc in spatial WM. The medial prefrontal cortex (mPFC) is a key brain region mediating WM. However, the role of mPFC Arc in WM is still uncertain. To investigate whether mPFC Arc protein is involved in WM performance, delayed non-match to sample (DNMS) T-maze task was performed in rats with or without blocking new synthesis of mPFC Arc. In DNMS task, a 10-s or 30-s delay between the sample run and the choice run was given to evaluate WM performance. To block new Arc protein synthesis during the DNMS task, Arc antisense oligodeoxynucleotides (ODNs) were injected to the bilateral mPFC. The results show that, in rats without surgery for cannula implantation and subsequent intracerebral injection of ODNs, WM was functioning well during the DNMS task with a delay of 10 s but not 30 s, which was accompanied with a significantly increased level of mPFC Arc protein, indicating a possible link between enhanced Arc protein expression and the performance of WM. After preventing the enhancement of mPFC Arc protein expression with Arc antisense ODNs, rat's WM performance was impaired. These findings support enhanced mPFC Arc protein expression playing a role during WM performance.

Detrimental Effects of Chlorhexidine on Articular Cartilage Viability, Matrix, and Mechanics.

BACKGROUND: Chlorhexidine gluconate (CHG) solution is commonly used as an antiseptic irrigation for bacterial decontamination during orthopaedic surgery. Although the chondrotoxicity of CHG on articular cartilage has been reported, the full extent of CHG-related chondrotoxicity and its effects on the extracellular matrix and mechanical properties are unknown. PURPOSE: To investigate the in vitro effects of a single 1-minute CHG exposure on the viability, biochemical content, and mechanics of native articular cartilage explants. STUDY DESIGN: Controlled laboratory study. METHODS: Articular cartilage explants (6 per group) were harvested from femoral condyles of the porcine stifle and sectioned at tidemark. Explants were bathed in CHG solution (0.05% CHG in sterile water) at varying concentrations (0% control, 0.01% CHG, and 0.05% CHG) for 1 minute, followed by complete phosphate-buffered saline wash and culture in chondrogenic medium. At 7 days after CHG exposure, cell viability, matrix content (collagen and glycosaminoglycan [GAG]), and compressive mechanical properties (creep indentation testing) were assessed. RESULTS: One-minute CHG exposure was chondrotoxic to explants, with both 0.05% CHG (2.6% ± 4.1%) and 0.01% CHG (76.3% ± 8.6%) causing a decrease in chondrocyte viability compared with controls (97.5% ± 0.6%; P < .001 for both). CHG exposure at either concentration had no significant effect on collagen content, while 0.05% CHG exposure led to a significant decrease in mean GAG per wet weight compared with the control group (2.6% ± 1.7% vs 5.2% ± 1.9%; P = .029). There was a corresponding weakening of mechanical properties in explants treated with 0.05% CHG compared with controls, with decreases in mean aggregate modulus (177.8 ± 90.1 kPa vs 280.8 ± 19.8 kPa; P < .029) and shear modulus (102.6 ± 56.5 kPa vs 167.9 ± 16.2 kPa; P < .020). CONCLUSION: One-minute exposure to CHG for articular cartilage explants led to dose-dependent decreases in chondrocyte viability, GAG content, and compressive mechanical properties. This raises concern for the risk of mechanical failure of the cartilage tissue after CHG exposure. CLINICAL RELEVANCE: Clinicians should be judicious regarding the use of CHG irrigation at these concentrations in the presence of native articular cartilage.

Comparison of Early Complication Rates After High Tibial Osteotomy Versus Unicompartmental Knee Arthroplasty for Knee Osteoarthritis.

Background: Although both high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) can be utilized to treat unicompartmental osteoarthritis (OA) in select patients, the early complication rates between the 2 procedures are not well understood. Understanding of the complication profiles for both procedures would help clinicians counsel patients with unicompartmental knee OA who may be eligible for either treatment option. Purpose: To compare the 30-day complication rates after HTO versus UKA for the treatment of knee OA using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. Study Design: Cohort study; Level of evidence, 3. Methods: NSQIP registries between 2006 and 2019 were queried using Current Procedural Terminology codes to identify patients undergoing HTO and UKA for knee OA. Patients >60 years of age were excluded. Patient demographics, preoperative comorbidities, and intraoperative data were collected. Postoperative 30-day complications, including venous thromboembolism (VTE), urinary tract infection (UTI), transfusion, surgical-site infection (SSI), and reoperations were recorded. Complication rates between treatment groups were compared using a multivariate logistic regression model adjusted for sex, age, body mass index, steroid use, respiratory status (smoking/dyspnea/chronic obstructive pulmonary disease), diabetes, and hypertension. Results: A total of 156 patients treated with HTO and 4755 patients treated with UKA for knee OA were identified. Mean patient ages were 46 years for the HTO group and 53.4 years for the UKA group. Operative time was significantly longer in the HTO group versus the UKA group (112 minutes vs 90 minutes; P < .001). Multivariate analyses found no significant differences in VTE (1.3% vs 0.6%), UTI (0.6% vs 0.3%), transfusion (0.6% vs 0.2%), deep SSI (0.6% vs 0.1%), and reoperation (1.3% vs 1%) rates between HTO and UKA groups. The HTO group had a higher rate of superficial SSI compared with the UKA group (2.6% vs 0.6%; P = .006) (adjusted odds ratio, 4.2; 95% CI, 1.4-12.5; P = .01). Conclusion: There were no differences in 30-day VTE, UTI, transfusion, deep SSI, and reoperation rates for HTO versus UKA in the treatment of knee OA. HTO was associated with a higher rate of superficial SSI compared with UKA. These findings serve to guide clinicians in counseling patients regarding the early risks after HTO and UKA.

Low early complication rates after arthroscopic meniscus repair and meniscectomy.

PURPOSE: To evaluate the 30-day complication rates after arthroscopic meniscus repair and meniscectomy using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, with subgroup analysis of patients aged > 40 years. METHODS: NSQIP registries between 2006 and 2019 were queried using Current Procedural Terminology codes to identify patients undergoing arthroscopic meniscus repair (CPT 29882, 29883) and meniscectomy (29880, 29881). The following 30-day complications were assessed: pulmonary embolism (PE), venous thromboembolism (VTE), surgical site infection (SSI), reoperation, and readmission. Complications rates between treatment groups were compared using multivariate logistic regression analyses adjusted for sex, age, steroid use, and smoking/dyspnoea/COPD. A subgroup analysis was performed for patients aged > 40 years. RESULTS: A total 6354 meniscus repairs and 99,372 meniscectomies were identified. Complication rates were < 1% for both meniscus repair and meniscectomy. Meniscus repair was associated with significantly higher rates of PE, VTE, and readmission compared to meniscectomy: PE (0.2% vs 0.1%, p < 0.001), VTE (0.8% vs 0.4%, p < 0.001), superficial SSI (0.1% vs 0.2%, n.s), deep SSI (0.07% vs 0.1%, n.s), reoperation (0.5% vs 0.4%, n.s), and readmission (0.9% vs 0.8%, p = 0.003). Among patients aged > 40 years, complication rates were < 1.3% for both meniscus repair and meniscectomy. Similar trends and rates were found in patients aged > 40 years undergoing meniscus repair versus meniscectomy: PE (0.38% vs 0.12%, p < 0.001), VTE (1.07% vs 0.46%, p < 0.001), superficial SSI (0.03% vs 0.19%, n.s), deep SSI (0.1% vs 0.06%, n.s), reoperation (0.48% vs 0.43%, n.s), and readmission (1.2% vs 0.85%, p = 0.01). CONCLUSION: Arthroscopic meniscus repair and meniscectomy are both low-risk procedures with 30-day complication rates < 1% overall and < 1.3% among patients aged > 40 years. These findings support meniscus repair whenever feasible in the setting of preserved articular cartilage. Understanding of the short-term complication rates after arthroscopic meniscus repair and meniscectomy can aid surgeons in providing comprehensive preoperative counselling to patients considering such treatments, specifically when discussing the risks and benefits of meniscus repair. LEVEL OF EVIDENCE: III.

Measurement of Medial Tibial Eminence Dimensions for the Clinical Evaluation of ACL-Injured Knees: A Comparison between CT and MRI.

Anterior cruciate ligament (ACL) injuries commonly lead to translational and rotational tibiofemoral instability. The morphology of the medial tibial eminence (MTE) has received increased attention regarding its role in tibiofemoral stability in ACL-injured knees. Therefore, quantification of MTE dimensions on clinical imaging may help clinicians predict knee stability after ACL injury. Although magnetic resonance imaging (MRI) is routinely obtained in patients with ACL injuries, whether the dimensions of the MTE can be accurate quantified on MRI is unknown. The purpose of this study was to assess the degree of correlation between measurements of MTE height and width on computed tomography (CT) versus MRI. An institutional picture archiving and communication system imaging database was used to identify patients aged between 15 and 60 years who received concurrent MRI and CT of the same knee within a 1-year interval. Knees with significant arthrosis, deformity, intraarticular fracture, or hardware-related artifact that obscured visualization of the MTE were excluded. Mean differences and interstudy agreement between CT and MRI MTE measurements were compared using concordance correlation coefficient (r c) and Bland-Altman analysis. A total of 41 knees in 38 patients (mean age, 37 years; 82% male) were analyzed. Interrater reliability for CT and MRI measurements was high (intraclass correlation coefficient = 0.740-0.954). On coronal CT and MRI, mean MTE height measurements were 10.4 ± 1.9 and 10.4 ± 1.8 mm, respectively; mean MTE width measurements were 14.6 ± 3.6 and 14.2 ± 3.0 mm, respectively. On sagittal CT and MRI, mean MTE height measurements were 11.6 ± 1.7 and 11.7 ± 1.7 mm, respectively; mean MTE width measurements were 36.5 ± 4.8 and 36.2 ± 5.0 mm, respectively. Good agreement was observed between CT and MRI measurements of MTE height and width on coronal and sagittal planes (r c = 0.947-0.969). Measurements of MTE height and width were similar on MRI relative to CT on both coronal and sagittal planes. MRI may be suitable for characterizing the dimensions of the MTE when clinically evaluating patients with ACL injuries, potentially allowing for individualized patient care.

Does the Choice of Acellular Scaffold and Augmentation With Bone Marrow Aspirate Concentrate Affect Short-term Outcomes in Cartilage Repair? A Systematic Review and Meta-analysis.

BACKGROUND: Matrix-induced chondrogenesis (MIC) is a promising treatment option for critical-size cartilage lesions of the knee; however, there exists substantial heterogeneity in the choice of acellular scaffold matrix for MIC cartilage repairs. HYPOTHESIS: The choice of acellular matrix will not affect patient outcomes after MIC cartilage repair procedures, and the addition of concentrated bone marrow aspirate (cBMA) will improve short-term patient outcomes regardless of matrix choice. STUDY DESIGN: Meta-analysis; Level of evidence, 4. METHODS: Studies were stratified by matrix type: multilayered, single layered, and gel based. Continuous outcomes were analyzed with pairwise meta-analysis using the inverse variance model with random effects applied. Binary outcomes were analyzed as pooled proportions in a single-arm fashion; after which, reconstruction of relative risks (RRs) with confidence intervals was performed using the Katz logarithmic method. RESULTS: A total of 876 patients were included: 469 received multilayered bioscaffolds; 238, gel-based scaffolds; and 169, single-layered scaffolds. The mean age of patients was 36.2 years (95% CI, 33.9 to 38.4), while the mean lesion size was 3.91 cm2 (95% CI, 3.40 to 4.42). The weighted mean follow-up was 23.8 months (95% CI, 20.1 to 27.6). Multilayered bioscaffolds were most effective at improving visual analog scale scores (P = .03; weighted mean difference [WMD], -4.44 [95% CI, -4.83 to -4.06]; P < .001). There were significantly lower risks of incomplete defect filling for gel-based scaffolds when compared with multilayered scaffolds (RR, 0.78 [95% CI, 0.69 to 0.88]; P < .001) and single-layered scaffolds (RR, 0.58 [95% CI, 0.41 to 0.81]; P = .001). Augmentation with cBMA further improved clinical scores across all scaffolds, with significant improvements in Tegner score (P = .02), while decreasing incomplete defect filling rates as well. There was significantly greater improvement in visual analog scale scores (P = .01) for single-layered scaffolds with cBMA augmentation (WMD, -4.88 [95% CI, -5.38 to -4.37]; P < .001) as compared with single-layered scaffolds without cBMA augmentation (WMD, -4.08 [95% CI, -4.46 to -3.71]; P < .001). All significant improvements were below their respective minimum clinically important differences. CONCLUSION: While cartilage repair with acellular scaffolds provides significant improvements in pain and function for patients, there is insufficient clinical evidence to suggest which scaffold material is the most superior in influencing such improvements. The enhancement of cartilage repair procedures with cBMA may provide further functional improvements and improve defect filling; however, more long-term evidence is required to evaluate the effects.

Topographical Characterization of the Young, Healthy Human Femoral Medial Condyle.

OBJECTIVE: The medial femoral condyle of the knee exhibits some of the highest incidences of chondral degeneration. However, a dearth of healthy human tissues has rendered it difficult to ascertain whether cartilage in this compartment possesses properties that predispose it to injuries. Assessment of young, healthy tissue would be most representative of the tissue's intrinsic properties. DESIGN: This work examined the topographical differences in tribological, tensile, and compressive properties of young (n = 5, 26.2 ± 5.6 years old), healthy, human medial femoral condyles, obtained from viable allograft specimens. Corresponding to clinical incidences of pathology, it was hypothesized that the lowest mechanical properties would be found in the posterior region of the medial condyle, and that tissue composition would correspond to the established structure-function relationships of cartilage. RESULTS: Young's modulus, ultimate tensile strength, aggregate modulus, and shear modulus in the posterior region were 1.0-, 2.8-, 1.1-, and 1.0-fold less than the values in the anterior region, respectively. Surprisingly, although glycosaminoglycan content is thought to correlate with compressive properties, in this study, the aggregate and shear moduli correlated more robustly to the amount of pyridinoline crosslinks per collagen. Also, the coefficient of friction was anisotropic and ranged 0.22-0.26 throughout the condyle. CONCLUSION: This work showed that the posteromedial condyle displays lower tensile and compressive properties, which correlate to collagen crosslinks and may play a role in this region's predisposition to injuries. Furthermore, new structure-function relationships may need to be developed to account for the role of collagen crosslinks in compressive properties.

Trends and complications of distal biceps tendon repair among American Board of Orthopaedic Surgery part II oral examination candidates.

BACKGROUND: Surgical fixation of distal biceps tendon ruptures can restore supination strength and minimize biceps fatigue, resulting in high patient satisfaction rates. Surgical approaches can vary (single incision vs. double incision), and the number of fixation techniques has increased in recent years. The reported rate of postoperative complications after surgical repair of distal biceps tendon injuries is high, ranging from 15% to 35%. The purpose of this study was to assess the trends and postoperative complication profile among newly trained surgeons who performed distal biceps tendon repairs utilizing the American Board of Orthopaedic Surgery database. METHODS: The American Board of Orthopaedic Surgery database was retrospectively queried for patients treated with distal biceps tendon repair by part II examination candidates between 2017 and 2020. Distal biceps tendon repairs were isolated using the Current Procedural Terminology code 24,342. Distal triceps tendon injuries were excluded with International Classification of Diseases code S46.3∗∗. Patient demographics, intraoperative data, and surgeon fellowship training were collected. Surgeon-reported postoperative 90-day complications, including general anesthetic, medical, and surgical complications, rates of readmission, and rates of reoperation were recorded. Comparisons of rates among patient groups organized by surgeon fellowship training were performed using the chi-squared test. RESULTS: A total of 2089 distal biceps tendon repairs were included in the analysis. The average patient age was 47.5 yr, and 97.3% of patients were men. The majority of cases was performed by surgeons with fellowship training in sports medicine, hand/upper extremity, and shoulder and elbow, with 867 (41.5%) cases performed by sports medicine-trained surgeons, 740 (35.4%) by hand/upper extremity-trained surgeons, and 313 (15.0%) by shoulder and elbow-trained surgeons. In total, 608 (29.1%) patients experienced an anesthetic (0.2%), medical (1.1%), or surgical (28.2%) complication. The most common surgical complications were nerve injury (20.6%), failure of tendon repair or fixation (2.4%), and infection (1.7%). The overall reoperation rate was 2.4%. There were no significant differences in complication or reoperation rates among subspecialty training received. DISCUSSION AND CONCLUSION: Among newly trained surgeons, those with fellowship training in sports medicine, hand/upper extremity, and shoulder and elbow performed the most distal biceps tendon repairs, and there was no difference in complication rates among subspecialty training received. Complication rates after distal biceps tendon repair performed by newly trained surgeons were similar to those previously reported in large cohort studies, with nerve injury as the most common complication.

Outcomes of Arthroscopic Lysis of Adhesions for the Treatment of Postoperative Knee Arthrofibrosis: A Systematic Review.

Background: Postoperative knee arthrofibrosis is a common and potentially detrimental complication affecting knee function and gait. Several cohort studies have reported good outcomes after arthroscopic lysis of adhesions (LOA) with manipulation under anesthesia (MUA). Purpose: To review the literature assessing the efficacy and complications of arthroscopic LOA and MUA for postoperative arthrofibrosis of the knee and evaluate whether any relevant subgroups are associated with different clinical presentation and outcomes. Study Design: Systematic review; Level of evidence, 4. Methods: This review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Eligible studies published from January 1, 1990, to April 1, 2021, were identified through a search of the US National Library of Medicine (PubMed/MEDLINE), EMBASE, and Cochrane databases. All studies included in this analysis included pre- and postoperative range of motion measurements for their treated patients. Studies reporting outcomes for patients with isolated cyclops lesions after anterior cruciate ligament reconstruction were excluded. Results: Eight studies comprising 240 patients were included. The mean time from index surgery to arthroscopic LOA and MUA was 8.4 months, and the mean postoperative follow-up was at 31.2 months. All studies demonstrated a significant improvement (41.6°) in arc of motion after arthroscopic LOA. Clinically significant improvements in outcome measures, including the International Knee Documentation Committee, Western Ontario and McMaster Universities Osteoarthritis Index, and Knee injury and Osteoarthritis Outcome Score, were reported after arthroscopic LOA across all applicable studies. Of 240 patients, a single complication (synovial fistula) occurred after LOA and MUA, which resolved without intervention. Conclusion: The results of this review indicated that arthroscopic LOA and MUA is a safe and efficacious treatment for postoperative arthrofibrosis of the knee.

Osteochondral Allografts in Knee Surgery: Narrative Review of Evidence to Date.

Knee articular cartilage defects can result in significant pain and loss of function in active patients. Osteochondral allograft (OCA) transplantation offers a single-stage solution to address large chondral and osteochondral defects by resurfacing focal cartilage defects with mature hyaline cartilage. To date, OCA transplantation of the knee has demonstrated excellent clinical outcomes and long-term survivorship. However, significant variability still exists among clinicians with regard to parameters for graft acceptance, surgical technique, and rehabilitation. Technologies to optimize graft viability during storage, improve osseous integration of the allograft, and shorten recovery timelines after surgery continue to evolve. The purpose of this review is to examine the latest evidence on treatment indications, graft storage and surgical technique, patient outcomes and survivorship, and rehabilitation after surgery.

Securing Transplanted Meniscal Allografts Using Bone Plugs Results in Lower Risks of Graft Failure and Reoperations: A Meta-analysis.

BACKGROUND: Meniscal allograft transplant (MAT) is an important treatment option for young patients with deficient menisci; however, there is a lack of consensus on the optimal method of allograft fixation. HYPOTHESIS: The various methods of MAT fixation have measurable and significant differences in outcomes. STUDY DESIGN: Meta-analysis; Level of evidence, 4. METHODS: A single-arm meta-analysis of studies reporting graft failure, reoperations, and other clinical outcomes after MAT was performed. Studies were stratified by suture-only, bone plug, and bone bridge fixation methods. Proportionate rates of failure and reoperation for each fixation technique were pooled with a mixed-effects model, after which reconstruction of relative risks with confidence intervals was performed using the Katz logarithmic method. RESULTS: A total of 2604 patients underwent MAT. Weighted mean follow-up was 4.3 years (95% CI, 3.2-5.6 years). During this follow-up period, graft failure rates were 6.2% (95% CI, 3.2%-11.6%) for bone plug fixation, 6.9% (95% CI, 4.5%-10.3%) for suture-only fixation, and 9.3% (95% CI, 6.2%-13.9%) for bone bridge fixation. Transplanted menisci secured using bone plugs displayed a lower risk of failure compared with menisci secured via bone bridges (RR = 0.97; 95% CI, 0.94-0.99; P = .02). Risks of failure were not significantly different when comparing suture fixation to bone bridge (RR = 1.02; 95% CI, 0.99-1.06; P = .12) and bone plugs (RR = 0.99; 95% CI, 0.96-1.02; P = .64). Allografts secured using bone plugs were at a lower risk of requiring reoperations compared with those secured using sutures (RR = 0.91; 95% CI, 0.87-0.95; P < .001), whereas allografts secured using bone bridges had a higher risk of reoperation when compared with those secured using either sutures (RR = 1.28; 95% CI, 1.19-1.38; P < .001) or bone plugs (RR = 1.41; 95% CI, 1.32-1.51; P < .001). Improvements in Lysholm and International Knee Documentation Committee scores were comparable among the different groups. CONCLUSION: This meta-analysis demonstrates that bone plug fixation of transplanted meniscal allografts carries a lower risk of failure than the bone bridge method and has a lower risk of requiring subsequent operations than both suture-only and bone bridge methods of fixation. This suggests that the technique used in the fixation of a transplanted meniscal allograft is an important factor in the clinical outcomes of patients receiving MATs.

Clinical outcomes of open hip abductor tendon repair with minimum two-year follow-up.

BACKGROUND: The results of open hip abductor tendon repair remains poorly defined. We sought to present the results and complications of this procedure using modern suture anchor fixation. MATERIALS AND METHODS: Our prospective institutional hip preservation registry was queried for all patients who underwent open hip abductor tendon repair with minimum 2-year follow-up were identified. Demographic, clinical, intraoperative, and functional outcome details were recorded. Patient-reported outcome scores (PROs) including the modified Harris Hip Score (mHHS), HOS-ADL, HOS-S, and iHOT-33 were collected for the preoperative and final postoperative state. Risk factors for lower final mHHS and change in mHHS were analysed using a multiple regression model. RESULTS: A total of 21 patients with mean 48 months clinical follow-up (range 24-84 months). Median mHHS improved from 49.50 preoperatively to 82.50 postoperatively (p < 0.001), median HOS-ADL improved from 60.29 to 82.35 (p = 0.001), median HOS-S improved from 37.50 to 60.00 (p = 0.04), and median iHOT-33 improved from 29.81 to 70.15 (p = 0.001). All patients had +4 or +5 hip abductor strength at final in-person examination at mean 17 months postoperatively. All patients with a preoperative Trendelenburg gait had complete resolution at final examination. There 2 complications, and no patient had re-tear or revision surgery. LCEA < 25° and a history of prior ipsilateral hip surgery were independently predictive of smaller improvement in mHHS at final follow-up. CONCLUSIONS: Open abductor tendon repair is a safe and effective procedure that provides sustained symptomatic and functional improvements at mid-term follow-up.

Return to Work and Sport After Distal Femoral Osteotomy: A Systematic Review.

CONTEXT: Distal femoral osteotomy (DFO) is a joint preservation procedure that corrects genu valgum deformities and patellofemoral maltracking, thereby restoring kinematics and unloading contact pressures in the lateral tibiofemoral and patellofemoral compartments. OBJECTIVE: To evaluate the rates of return to work (RTW) and return to sport (RTS) after DFO for valgus malalignment and lateral compartment osteoarthritis through a systematic review of the literature. DATA SOURCES: A systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted on the PubMed, Cochrane, and Embase databases. STUDY SELECTION: The search terms femoral osteotomy AND (sports OR work) were used. Studies in which patients underwent concomitant total knee arthroplasty were excluded. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 4 (systematic review of level 4 studies). DATA EXTRACTION: Data included the number of patients, age, gender, laterality of operation, time to follow-up, rate of RTW and RTS, time to RTS, activity level on return, and activity level scores (Tegner, Marx, Lysholm, and the International Knee Documentation Committee). Risk of bias was assessed using the Methodological Index for Non-Randomized Studies (MINORS) criteria. RESULTS: Seven articles with 194 patients were included. The average age ranged from 19 to 49 years with a mean postoperative follow-up range of 36 to 90 months. RTW data were available for 125 patients, of whom 42.1% to 91.3% returned by final follow-up. Data on RTS were available for 149 patients, of whom 70% to 100% returned at a range of 8.3 to 16.9 months postoperatively, and 41.6% to 100% returned to the same or greater level of sports activity. The Tegner and Marx activity level scores ranged from 3 to 4 and from 5 to 11, respectively, at final follow-up. CONCLUSION: Patients treated with DFO reported high rates of RTW and RTS, with most patients being able to return to recreational sport after surgery.

Measurement of acetabular wall indices: comparison between CT and plain radiography.

The purpose of this study was to compare measurements of anterior wall index (AWI) and posterior wall index (PWI) on computed tomography (CT) to those on radiographs (XR). A consecutive cohort of 33 patients (45 hips total) being evaluated for hip pain with both XR and CT was examined. Preoperative measurements of AWI and PWI were performed utilizing supine anteroposterior pelvic XR and coronal and swiss axial CT scans by two independent raters. Mean differences between XR and CT measurements were compared, and agreement between measurements was assessed using the concordance correlation coefficient (rc ) and Bland-Altman analysis. A total of 39 hips in 28 patients were analyzed. The mean patient age was 31.1 ± 9.0 years, and 50% were female. Mean AWI and PWI on XR was 0.50 ± 0.14 and 0.91 ± 0.12, respectively. Measured values of AWI were consistently larger (0.08 ± 0.10, P < 0.01) on XR compared with both coronal and swiss axial CT, with moderate agreement between XR and CT measurements (rc = 0.68-0.70). Measured values of PWI were consistently smaller (0.15 ± 0.12, P < 0.05) on XR compared with both coronal and swiss axial CT, with poor agreement between XR and CT measurements (rc = 0.37-0.45). Measured values of acetabular wall indices on XR were consistently larger for AWI and smaller for PWI relative to CT. Agreement between XR and CT measures of the indices were moderate to poor. This highlights the need for standardization of XR- and CT-based measurements to improve assessment of acetabular coverage and subsequent clinical decision-making.

Knee orthopedics as a template for the temporomandibular joint.

Although the knee joint and temporomandibular joint (TMJ) experience similar incidence of cartilage ailments, the knee orthopedics field has greater funding and more effective end-stage treatment options. Translational research has resulted in the development of tissue-engineered products for knee cartilage repair, but the same is not true for TMJ cartilages. Here, we examine the anatomy and pathology of the joints, compare current treatments and products for cartilage afflictions, and explore ways to accelerate the TMJ field. We examine disparities, such as a 6-fold higher article count and 2,000-fold higher total joint replacement frequency in the knee compared to the TMJ, despite similarities in osteoarthritis incidence. Using knee orthopedics as a template, basic and translational research will drive the development and implementation of clinical products for the TMJ. With more funding opportunities, training programs, and federal guidance, millions of people afflicted with TMJ disorders could benefit from novel, life-changing therapeutics.

Reporting in clinical studies on platelet-rich plasma therapy among all medical specialties: A systematic review of Level I and II studies.

BACKGROUND: The clinical practice of platelet-rich plasma (PRP) therapy has grown significantly in recent years in multiple medical specialties. However, comparisons of PRP studies across medical fields remain challenging because of inconsistent reporting of protocols and characterization of the PRP being administered. The purpose of this systematic review was to determine the quantity of level I/II studies within each medical specialty and compare the level of study reporting across medical fields. METHODS: The Cochrane Database, PubMed, and EMBASE databases were queried for level I/II clinical studies on PRP injections across all medical specialties. From these studies, data including condition treated, PRP processing and characterization, delivery, control group, and assessed outcomes were collected. RESULTS: A total of 132 studies met the inclusion and exclusion criteria and involved 28 different conditions across 8 specialties (cardiothoracic surgery, cosmetic, dermatology, musculoskeletal (MSK), neurology, oral maxillofacial surgery, ophthalmology, and plastic surgery). Studies on PRP for MSK injuries made up the majority of the studies (74%), with knee osteoarthritis and tendinopathy being most commonly studied. Of the 132 studies, only 44 (33%) characterized the composition of PRP used, and only 23 (17%) reported the leukocyte component. MSK studies were more likely to use patient-reported outcome measures to assess outcomes, while studies from other specialties were more likely to use clinician- or imaging-based objective outcomes. Overall, 61% of the studies found PRP to be favorable over control treatment, with no difference in favorable reporting between MSK and other medical specialties. CONCLUSIONS: The majority of level I/II clinical studies investigating PRP therapy across all medical specialties have been conducted for MSK injuries with knee osteoarthritis and tendinopathy being the most commonly studied conditions. Inconsistent reporting of PRP composition exists among all studies in medicine. Rigorous reporting in human clinical studies across all medical specialties is crucial for evaluating the effects of PRP and moving towards disease-specific and individualized treatment.

Diagnostic Arthroscopy of the Minipig Stifle (Knee) for Translational Large Animal Research.

To gain regulatory approval for the clinical use of knee biologics and devices in humans, translational large-animal studies are typically required. Animal models that permit second-look arthroscopy are valuable because they allow for longitudinal assessment of the treated tissue without needing to sacrifice the animal. The minipig is an ideal preclinical animal model for the investigation of therapies for the knee, in part because arthroscopy can be performed in its stifle (knee) joint with the use of standard surgical equipment used in humans. The purpose of this Technical Note is to describe a reproducible technique for diagnostic arthroscopy of the minipig stifle (knee) joint.

The Statistical Fragility of Platelet-Rich Plasma in Rotator Cuff Surgery: A Systematic Review and Meta-analysis.

BACKGROUND: The practice of evidence-based medicine relies on objective data to guide clinical decision-making with specific statistical thresholds conveying study significance. PURPOSE: To determine the utility of applying the fragility index (FI) and the fragility quotient (FQ) analysis to randomized controlled trials (RCTs) evaluating the utilization of platelet-rich plasma (PRP) in rotator cuff repairs (RCRs). STUDY DESIGN: Systematic review and meta-analysis. METHODS: RCTs pertaining to the utilization of PRP in surgical RCRs published in 13 peer-reviewed journals from 2000 to 2020 were evaluated. The FI was determined by manipulating each reported outcome event until a reversal of significance was appreciated. The associated FQ was determined by dividing the FI by the sample size. RESULTS: Of the 9746 studies screened, 19 RCTs were ultimately included for analysis. The overall FI incorporating all 19 RCTs was only 4, suggesting that the reversal of only 4 events is required to change study significance. The associated FQ was determined as 0.092. Of the 43 outcome events reporting lost to follow-up data, 13 (30.2%) represented lost to follow-up >4. CONCLUSION: Our analysis suggests that RCTs evaluating PRP for surgical RCRs may lack statistical stability with only a few outcome events required to alter trial significance. Therefore, we recommend the reporting of an FI and an FQ in conjunction with P value analysis to carefully interpret the integrity of statistical stability in future comparative trials. CLINICAL RELEVANCE: Clinical decisions are often informed by statistically significant results. Thus, a true understanding of the robustness of the statistical findings informing clinical decision-making is of critical importance.