Evaluating the Need for Preoperative MRI Before Primary Hip Arthroscopy in Patients 40 Years and Younger With Femoroacetabular Impingement Syndrome: A Multicenter Comparative Analysis

BACKGROUND: Routine hip magnetic resonance imaging (MRI) before arthroscopy for patients with femoroacetabular impingement syndrome (FAIS) offers questionable clinical benefit, delays surgery, and wastes resources. PURPOSE: To assess the clinical utility of preoperative hip MRI for patients aged ≤40 years who were undergoing primary hip arthroscopy and who had a history, physical examination findings, and radiographs concordant with FAIS. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Included were 1391 patients (mean age, 25.8 years; 63% female; mean body mass index, 25.6) who underwent hip arthroscopy between August 2015 and December 2021 by 1 of 4 fellowship-trained hip surgeons from 4 referral centers. Inclusion criteria were FAIS, primary surgery, and age ≤40 years. Exclusion criteria were MRI contraindication, reattempt of nonoperative management, and concomitant periacetabular osteotomy. Patients were stratified into those who were evaluated with preoperative MRI versus those without MRI. Those without MRI received an MRI before surgery without deviation from the established surgical plan. All preoperative MRI scans were compared with the office evaluation and intraoperative findings to assess agreement. Time from office to arthroscopy and/or MRI was recorded. MRI costs were calculated. RESULTS: Of the study patients, 322 were not evaluated with MRI and 1069 were. MRI did not alter surgical or interoperative plans. Both groups had MRI findings demonstrating anterosuperior labral tears treated intraoperatively (99.8% repair, 0.2% debridement, and 0% reconstruction). Compared with patients who were evaluated with MRI and waited 63.0 ± 34.6 days, patients who were not evaluated with MRI underwent surgery 6.5 ± 18.7 days after preoperative MRI. MRI delayed surgery by 24.0 ± 5.3 days and cost a mean $2262 per patient. CONCLUSION: Preoperative MRI did not alter indications for primary hip arthroscopy in patients aged ≤40 years with a history, physical examination findings, and radiographs concordant with FAIS. Rather, MRI delayed surgery and wasted resources. Routine hip MRI acquisition for the younger population with primary FAIS with a typical presentation should be challenged

Defining the baseline transcriptional fingerprint of rabbit hamstring autograft

Anterior cruciate ligament (ACL) injuries are common and of high relevance given their significant effects on patient function, quality of life, and posttraumatic arthritis. To date, investigators have reported on the expression of genes classically associated with tendon and ligament reconstruction, including decorin (DCN) and collagen type 1 (COL1A1 and COL1A2). However, the transcriptional fingerprint for hamstring tendons, one of the most common autografts used for ACLR, remains to be determined. The purpose of this study was to characterize the baseline transcriptional state of semitendinosus autografts in a rabbit model for ACLR and to employ such characterization to guide scientifically-driven target gene selection for future analyses. Next generation RNA sequencing was performed on whole semitendinosus autografts from four New Zealand White rabbits (mean age: 193 ± 0 days, mean weight: 2.78 kg ± 0.15 kg) and subsequently analyzed using gene enrichment and protein-protein interaction network analysis. Decorin, Secreted Protein Acidic and Cysteine Rich (SPARC), Collagen type 1, and Proline and Arginine Rich End Leucine Rich Repeat Protein (PRELP) and were determined to be the highest expressed genes with tendon-associated ontology. These results strengthen the association between genes such as DCN, COL1A1, and COL1A2 and tendon tissues as well as provide the novel addition of further high-expression, tendon characteristic genes such as SPARC and PRELP to provide guidance as to which molecules serve as high-signal candidates for future ACL research. In addition, this paper provides open-access to the expression fingerprint of hamstring autograft for ACLR in New Zealand White rabbits, thus providing a readily-accessible collaborative reference, in alignment with ethical animal research principles

Loss of histone methyltransferase Ezh2 stimulates an osteogenic transcriptional program in chondrocytes but does not affectcartilage development

Ezh2 is a histone methyltransferase that suppresses osteoblast maturation and skeletal development. We evaluated the roleof Ezh2 in chondrocyte lineage differentiation and endochondral ossification. Ezh2 was genetically inactivated in the mesenchymal, osteoblastic, and chondrocytic lineages in mice using the Prrx1-Cre,Osx1-Cre, and Col2a1-Cre drivers, respectively. Wild-type and conditional knockout mice were phenotypically assessed by grossmorphology, histology, and micro-CT imaging. Ezh2-deficient chondrocytes in micromass culture models were evaluated usingRNA-sequencing, histologic evaluation, and western blotting. Aged mice with Ezh2 deficiency were also evaluated for prematuredevelopment of osteoarthritis using radiographic analysis. Ezh2 deficiency in murine chondrocytes reduced bone density at 4 weeks of age, although caused no other gross developmentaleffects. Knockdown of Ezh2 in chondrocyte micromass cultures resulted in a global reduction in trimethylation of histone 3lysine 27 (H3K27me3) and altered differentiation in vitro. RNA-seq analysis revealed enrichment of an osteogenic gene expressionprofile in Ezh2 deficient chondrocytes. Joint development proceeded normally in the absence of Ezh2 in chondrocytes withoutinducing excessive hypertrophy or premature osteoarthritis in vivo. In summary, loss of Ezh2 reduced H3K27me3 levels, increased expression of osteogenic genes in chondrocytes, and resulted ina transient post-natal bone phenotype. Remarkably, Ezh2 activity is dispensable for normal chondrocyte maturation and endochondralossification in vivo, even though it appears to have a critical role during early stages of mesenchymal lineage-commitment

Cell-based tissue engineering strategies used in the clinical repair of articular cartilage

One of the most important issues facing cartilage tissue engineering is the inability to move technologies into the clinic. Despite the multitude of review articles on the paradigm of biomaterials, signals, and cells, it is reported that 90% of new drugs that advance past animal studies fail clinical trials (1). The intent of this review is to provide readers with an understanding of the scientific details of tissue engineered cartilage products that have demonstrated a certain level of efficacy in humans, so that newer technologies may be developed upon this foundation. Compared to existing treatments, such as microfracture or autologous chondrocyte implantation, a tissue engineered product can potentially provide more consistent clinical results in forming hyaline repair tissue and in filling the entirety of the defect. The various tissue engineering strategies (e.g., cell expansion, scaffold material, media formulations, biomimetic stimuli, etc.) used in forming these products, as collected from published literature, company websites, and relevant patents, are critically discussed. The authors note that many details about these products remain proprietary, not all information is made public, and that advancements to the products are continuously made. Nevertheless, by fully understanding the design and production processes of these emerging technologies, one can gain tremendous insight into how to best use them and also how to design the next generation of tissue engineered cartilage products

Arthroscopic Preparation and Internal Fixation of an Unstable Osteochondritis Dissecans Lesion of the Knee

We present our arthroscopic technique for fixation of an unstable osteochondritis dissecans (OCD) lesion. This technique includes arthroscopic evaluation of cartilage and bone quality of the OCD fragment, hinging open the lesion, debridement of fibrous nonunion tissue, reducing the fragment, and obtaining multi-point compression screw fixation. This technique avoids the morbidity of an open arthrotomy and should be considered when treating an unstable OCD lesion with adequate bone for fixation

Treatment of Cartilage Defects With the Matrix-Induced Autologous Chondrocyte Implantation Cookie Cutter Technique

Focal cartilage defects lead to significant pain and disability, prompting the development of various options for biologic restoration of the articular surface. Although each technique and biologic implant provides various advantages and associated limitations, matrix-induced autologous chondrocyte implantation (MACI) has gained popularity given promising long-term results. We present a technique for the facile implantation of MACI membranes using cookie cutter instrumentation to aid in defect debridement and graft preparation. The technique described allows for efficient operative workflow while ensuring the creation of vertical, stable defect edges and a form-fitting MACI membrane in a readily implemented fashion

How Anterior Cruciate Ligament Injury was averted during Knee Collapse in a NBA Point Guard

Non-contact anterior cruciate ligament (ACL) injuries occur with rapid decelerations and pivoting. A recent injury to a high-level National Basketball Association (NBA) player demonstrated neuromuscular control and injury-sparing mechanisms that resulted in only minor ligament injury to the medial collateral ligament. We analyzed biomechanical mechanisms via publically available orthogonal 2-D video to demonstrate how this potential ACL injury was averted. Analysis of the knee injury mechanismdemonstrated that the NBA player experienced low ground reaction force, high sagittal plane fl exion, and maintenance of frontal plane stability with neuromuscular control. The outcome of these factors inhibited dynamic valgus collapse of the knee throughout the fall, avoiding ACL injury – a potentially career-altering injury. Many athletes, professional and recreational, will be subjected to similar mechanisms of injury and will have improved outcomes if they can successfully utilize preventive strategies of neuromuscular control to limit injury mechanisms.Pubmed link:https://www.ncbi.nlm.nih.gov/pubmed/28603786 </p