Faculty Bibliography

Osteoarthritis (OA) is a degenerative joint condition characterized by painful cartilage lesions that impair joint mobility. Current treatments such as lavage, microfracture, and osteochondral implantation fail to integrate newly formed tissue with host tissues, and establish a stable transition to subchondral bone. Similarly, tissue engineered grafts that facilitate cartilage and bone regeneration likewise are challenged by how to integrate the graft seamlessly with surrounding host cartilage and/or bone. This review centers on current approaches in promoting cartilage graft integration. It begins with an overview of articular cartilage structure and function, as well as degenerative changes to this relationship attributed to aging, disease, and trauma. A discussion of the current progress in integrative cartilage repair then follows, focusing on graft or scaffold design strategies targeting cartilage-cartilage and/or cartilage-bone integration. It is emphasized that integrative repair is required to ensure long term success of the cartilage graft and preserve the integrity of the newly engineered articular cartilage. Studies involving the use of enzymes, choice of cell source, biomaterial selection, growth factor incorporation, and stratified versus gradient scaffolds are therefore highlighted here. Moreover, models that accurately evaluate the ability of cartilage grafts to enhance tissue integrity and prevent ectopic calcification are also discussed. A summary and future directions section concludes the review.

OBJECTIVES: Meniscus tears are one of the most common knee injuries. Our goal is to investigate the failure rate for surgically repaired bucket-handle meniscus tears and compare clinical outcomes of repairs that failed versus those that did not, at a minimum 2-year follow-up interval. METHODS: 51 patients were identified in this retrospective cohort study who experienced bucket-handle meniscus tears that were isolated or with concomitant ACL injury. Inclusion criteria included age range from 13-55 years, confirmed bucket-handle meniscus tear by MRI and intraoperatively, and at least two-years of post-operative follow-up following index repair. Demographic data and outcome surveys were collected at a minimum of two-years follow-up after repair. RESULTS: Of the 51 patients that had a bucket-handle meniscal repair, 12 (23.5%) were defined as failures (return of symptoms alongside re-tear in the same zone of the repaired meniscus within two years of surgery). No demographic variables (age, sex, and BMI smoking status, location of tear, or concomitant ACL tear) significantly correlated with failure. The mean of the Sports and Recreation KOOS was significantly lower between the non-failure (87+/-14.4) and failure (70+/-17.2) cohorts (p=0.0072). The Quality of Life subscale was significantly lower between the non-failure (76+/-15.8) and failure (57+/-18.2) groups (p=0.0058). There was a significant difference in the post-operative Lysholm scores (p=0.0039) with a mean of 90+/-9.1 for the entire cohort and means of 92+/-8.4 and 83+/-8.6, for non-failure and failure groups, respectively. CONCLUSIONS: We found a higher failure rate (23.5%) for bucket-handle meniscus repairs at two-year follow up than has been cited in the literature, which is typically less than 20%, with significantly lower KOOS Quality of Life and Sports and Recreation subscales and Lysholm scores for the failure cohort. This is the first study to report these outcome scores solely for bucket-handle meniscus repairs, shedding light on the post-operative quality of life of patients with repair success or failure.

Objectives: Continuous gradient-echo (GRE) acquisition or "dynamic magnetic resonance imaging", allows for high-speed examination of pathologies based on joint motion. We sought to assess the efficacy of a radial GRE sequence with in the characterization of patellofemoral maltracking. Methods: Patients with suspected patellofemoral maltracking and asymptomatic volunteers were scanned using GRE (Siemens LiveView WIP; Malvern, PA, USA) at 3T in the axial plane at the patella level through a range of flexion-extension (0-30degree). The mean time to perform the dynamic component ranged from 3-7 mins. Lateral maltracking (amount patella moved laterally through knee ranging) was measured. Patella lateralization was categorized as normal (<= 2mm), mild (2-5mm), moderate (5-10mm), or severe (>10mm). Tibial tuberosity: trochlear groove (TT: TG) distance, trochlea depth, Insall-Salvati ratio, and patellofemoral cartilage quality (according to the modified Outerbridge grading system) were also assessed. Results: Eighteen symptomatic (6 men; 12 women, age range 14-51 years) and 10 asymptomatic subjects (6 men; 4 women, age range 25-68 years) were included. Two symptomatic patients underwent bilateral examinations. Lateralization in the symptomatic group was normal (n=10), mild (n=2), moderate (n=5) and severe (n=3). There was no abnormal maltracking in the volunteer group. Lateral tracking significantly correlated with TT: TG distance (F=38.0; p<.0001), trochlea depth (F=5.8; p=.023), Insall-Salvati ratio (F=4.642; p=.04) and Outerbridge Patella score (F=6.6; p=.016). Lateral tracking did not correlate with Outerbridge Trochlear score. Conclusion: Lateral tracking measured on GRE was found to significantly correlate with current measures of patellar instability including, TT: TG, trochlea depth, and the Insall-Salvati ratio. GRE is a rapid and easily performed addition to the standard protocol for kinematic patellofemoral motion and can add dynamic information on patellofemoral tracking. This may be help determine if an isolated MPFL or an MPFL reconstruction and tibial tubercle osteotomy is needed to treat patella instability

We retrospectively reviewed the records of 3 patients (3 knees) with a delayed type hypersensitivity reaction following Dermabond exposure after an orthopaedic knee procedure. Delayed hypersensitivity reactions are mediated by CD4+ helper T cells. The use of skin adhesives in place of traditional sutures is increasing in popularity given Dermabond's potential benefits of decreased wound infection rate and better wound approximation. However, hypersensitivity reactions to the cyanoacrylate material in Dermabond have been described. Differentiating hypersensitivity reactions from post-operative infections is important as septic arthritis is a potentially devastating complication. This case series presents the challenge of properly diagnosing and managing hypersensitivity reactions. Consultation with allergists and dermatologists may be appropriate for ascertaining the nature of the surgical site complication and proper management. The recommended management of hypersensitivity-type reactions is a course of topical steroids and infection work up if needed.

MicroCT imaging allows for noninvasive microstructural evaluation of mineralized bone tissue, and is essential in studies of small animal models of bone and joint diseases. Automatic segmentation and evaluation of articular surfaces is challenging. Here, we present a novel method to create knee joint surface models, for the evaluation of PTOA-related joint changes in the rat using an atlas-based diffeomorphic registration to automatically isolate bone from surrounding tissues. As validation, two independent raters manually segment datasets and the resulting segmentations were compared to our novel automatic segmentation process. Data were evaluated using label map volumes, overlap metrics, Euclidean distance mapping, and a time trial. Intraclass correlation coefficients were calculated to compare methods, and were greater than 0.90. Total overlap, union overlap, and mean overlap were calculated to compare the automatic and manual methods and ranged from 0.85 to 0.99. A Euclidean distance comparison was also performed and showed no measurable difference between manual and automatic segmentations. Furthermore, our new method was 18 times faster than manual segmentation. Overall, this study describes a reliable, accurate, and automatic segmentation method for mineralized knee structures from microCT images, and will allow for efficient assessment of bony changes in small animal models of PTOA.

PURPOSE: To establish how synovial fluid biomarker concentrations change in patients after anterior cruciate ligament (ACL) tears, with and without associated cartilage injury, with comparisons made to healthy controls. METHODS: Patients were prospectively enrolled between January 2013 and December 2014. Inclusion criteria included any patient undergoing knee arthroscopy. Patients with a confirmed ACL tear were allocated to either the ACL tear with cartilage injury group or the ACL tear without cartilage injury group based on intraoperative assessment. Patients who underwent an arthroscopic procedure with no injury history or symptoms in their contralateral knee were asked to provide samples to serve as healthy controls. These subjects may or may not have been the same ones with noted ACL pathology. The concentrations of 20 biomarkers were determined using a multiplex magnetic bead immunoassay. Biomarker concentrations were then compared between the 3 study groups (ACL tears with and without cartilage injury, and uninjured contralateral knees) using an analysis of variance test with pairwise comparisons. The minimal clinically important difference was calculated based on the standard error of measurement. RESULTS: The study included synovial fluid samples from 134 knees: 34 ACL tears without cartilage injury (mean age 34.0 years), 28 ACL tears with cartilage injury (mean age 36.3 years), and 72 healthy controls (mean age 41.1 years). Analysis of variance testing showed significant differences among groups for matrix metalloproteinase-3 (F = 81.8; P < .001), tissue inhibitor of metalloproteinase (TIMP)-1 (F = 7.9; P