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Background: Fresh osteochondral allograft (OCA) transplantation is an effective technique for the treatment of focal chondral and osteochondral defects in the knee. Coronal-plane malalignment leads to increased contact forces within a compartment and subsequently the cartilage repair site and may lead to higher failure rates. However, the magnitude of the effect of coronal-plane malalignment on graft survivorship and clinical outcomes has not been well characterized. Purpose: To evaluate how varus malalignment affects graft survival and patient-reported outcomes after isolated OCA transplantation of the medial femoral condyle (MFC). Study Design: Cohort study; Level of evidence, 3. Methods: A total of 70 patients (74 knees) who underwent primary OCA transplantation of the MFC between 2005 and 2019 were identified from a prospectively collected single-surgeon cartilage registry with a minimum 2-year follow-up. Coronal-plane alignment was evaluated utilizing standing hip-to-ankle radiographs. OCA failure, defined as removal of the graft or conversion to arthroplasty, and reoperations were recorded. Patient-reported outcomes were obtained preoperatively and postoperatively using the International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, modified Merle d'Aubigné–Postel score, and overall patient satisfaction score. Results: The mean mechanical tibiofemoral angle for patients with varus alignment was 3.9° of varus (range, 1.1° to 8.9°) and for patients with nonvarus alignment it was 0.02° of valgus (range, 3.6° varus to 4.6° valgus). Graft survivorship was 95.3% in the varus group and 95.8% in the nonvarus group (P =.918) at 5 years postoperatively. Reoperations after OCA transplantation occurred in 14.0% of the varus group and 22.6% of the nonvarus group (P =.336). The mean International Knee Documentation Committee total score improved from 45.2 preoperatively to 74.8 at latest follow-up in the varus group and from 40.5 preoperatively to 72.3 at latest follow-up in the nonvarus group. Patient satisfaction was >85%. Conclusion: Patients undergoing isolated OCA transplantation of the MFC had high rates (>90%) of graft survivorship and significant improvements in pain and function. Patients with mild preexisting varus malalignment were found to have no difference in the failure rate or clinical outcomes compared with patients with nonvarus alignment. [ABSTRACT FROM AUTHOR]

Articular cartilage is susceptible to impact injury. Impact may occur during events ranging from trauma to surgical insertion of an OsteoChondral Graft (OCG) into an OsteoChondral Recipient site (OCR). To evaluate energy density as a mediator of cartilage damage, a specialized drop tower apparatus was used to impact adult bovine samples while measuring contact force, cartilage surface displacement, and OCG advancement. When a single impact was applied to an isolated (non-inserted) OCG, force and surface displacement each rose monotonically and then declined. In each of five sequential impacts of increasing magnitude, applied to insert an OCG into an OCR, force rose rapidly to an initial peak, with minimal OCG advancement, and then to a second prolonged peak, with distinctive oscillations. Energy delivered to cartilage was confirmed to be higher with larger drop height and mass, and found to be lower with an interposed cushion or OCG insertion into an OCR. For both single and multiple impacts, the total energy density delivered to the articular cartilage correlated to damage, quantified as total crack length. The corresponding fracture toughness of the articular cartilage was 12.0 mJ/mm2. Thus, the biomechanics of OCG insertion exhibits distinctive features compared to OCG impact without insertion, with energy delivery to the articular cartilage being a factor highly correlated with damage.

IntroductionOsteochondral allograft (OCA) transplantation is a suitable treatment option for large osteochondral defects. Magnetic resonance imaging (MRI) is an objective, reproducible, noninvasive monitoring tool for postoperative assessment after cartilage surgery.ObjectiveTo correlate Osteochondral Allograft MRI Scoring System (OCAMRISS) in patients undergoing OCA transplantation in the knee with clinical outcomes and determine interobserver agreement of this scoring system.MethodsFifteen patients underwent OCA transplantation in the knee and received a postoperative MRI. Four examiners read each MRI and completed an OCAMRISS. Interobserver agreement and intraclass correlation coefficients (ICCs) were assessed. Clinical outcomes were evaluated. Correlation between the OCAMRISS and clinical outcomes was calculated using Spearman's correlation coefficients.ResultsInterobserver agreement on individual features of the OCAMRISS was superior (κ = 0.81-1.0) in 65% of comparisons, substantial (κ = 0.61-0.8) in 14%, moderate (κ = 0.41-0.6) in 18%, and fair (κ = 0.21-0.4) in 3%. Agreement among readers was very strong for the cartilage, bone, ancillary, and total scores with 96% of comparisons having an ICC >0.80. International Knee Documentation Committee (IKDC) function scores were correlated with OCAMRISS cartilage score (ρ = 0.53, P = 0.044) and total score (ρ = 0.67, P = 0.006). The Knee injury and Osteoarthritis Outcome Score (KOOS) sports/recreation subscale was correlated with OCAMRISS ancillary score (ρ = 0.58, P = 0.049) and total score (ρ = 0.64, P = 0.024). No correlation was observed with subchondral bone features of OCAMRISS and any of the outcome scores.ConclusionsThe recently described OCAMRISS is a reproducible grading system for in vivo evaluation after osteochondral allograft transplantation.

ObjectiveFibroblast-like synoviocytes (FLS) are key players in the synovial pathology of rheumatoid arthritis (RA). Currently, there is no treatment that specifically targets these aggressive cells. By combining 3 different "omics" data sets, i.e., 1) risk genes in RA, 2) differentially expressed genes, and 3) differential DNA methylation in RA versus osteoarthritis (OA) FLS, we identified LBH (limb bud and heart development) as a candidate gene in RA. The present study was undertaken to define the role of this gene in FLS.MethodsSynovial tissue specimens from RA and OA patients were collected at the time of joint replacement surgery. LBH expression was silenced using small interfering RNA or overexpressed using an LBH expression vector in primary FLS. Gene expression profiles were determined by microarray and assessed using Ingenuity Pathway Analysis. Effects of modified LBH expression were investigated in functional assays.ResultsLBH was expressed in the synovial lining layer in patients with RA. Transforming growth factor β1 significantly increased LBH expression in primary FLS, and platelet-derived growth factor BB decreased it. Pathway analysis of the transcriptome of LBH-deficient FLS compared to control FLS identified "cellular growth and proliferation" as the most significantly enriched pathway. In growth assays, LBH deficiency increased FLS proliferation. Conversely, LBH overexpression significantly inhibited cell growth. Cell cycle analysis demonstrated a marked increase in cells entering the cell cycle in LBH-deficient FLS compared to controls. LBH did not alter apoptosis.ConclusionLBH is a candidate gene for synovial pathology in RA. It is regulated by growth factors and modulates cell growth in primary FLS. Our data suggest a novel mechanism for synovial intimal hyperplasia and joint damage in RA.

BackgroundOsteochondral allograft (OCA) transplantation is an effective treatment for defects in the medial femoral condyle (MFC), but the procedure is limited by a shortage of grafts. Lateral femoral condyles (LFCs) differ in geometry from MFCs but may be a suitable graft source. The difference between articular surface locations of the knee can be evaluated with micro-computed tomography imaging and 3-dimensional image analysis.HypothesisLFC OCAs inserted into MFC lesions can provide a cartilage surface match comparable with those provided by MFC allografts.Study designControlled laboratory study.MethodsTwenty MFCs and 10 LFCs were divided into 3 groups: 10 MFC recipients (MFCr), 10 MFC donors (MFCd), and 10 LFC donors (LFCd). A 20-mm defect was created in the weightbearing portion of the MFCr. Two grafts, 1 MFCd and 1 LFCd, were implanted sequentially into each MFCr. Micro-computed tomography (μCT) images of the MFCr were acquired and analyzed to compare the topography of the original recipient site with the MFCd- and LFCd-repaired sites. Three-dimensional transformations were defined to register the defect site in the 3 scans of each MFCr. Vertical deviations from each voxel of the graft cartilage surface, relative to the intact recipient cartilage surface, were calculated and assessed as root mean square deviation and percentage graft area that was proud, sunk, and within the "acceptable" distance (±1.00 mm). The effect of repair (with MFC vs with LFC) on each of the surface match parameters is presented as mean ± SD and was assessed by t test: height deviation over area (root mean square, mm), graft area acceptable (%), area unacceptably proud (%), area unacceptably sunk (%), step-off height over circumference (root mean square, mm), graft circumference acceptable (%), circumference unacceptably proud (%), and circumference unacceptably sunk (%). Percentage data were arcsin transformed before statistical testing. An alpha level of 0.05 was used to conclude if variations were statistically significant.ResultsMFCr defects were filled with both orthotopic MFCd and nonorthotopic LFCd. Registered μCT images of the MFCr illustrate the cartilage surface contour in the sagittal and coronal planes, in the original intact condyle, as well as after OCA repairs. Specimen-specific surface color maps for the MFCr after implant of the MFCd and after implant of LFCd were generally similar, with some deviation near the edges. On average, the MFCr site exhibited a typical contour, and the MFCd and LFCd were slightly elevated. Both types of OCA-MFCd and LFCd-matched well, showing overall height deviations of 0.63 mm for area and 0.47 mm for step-off, with no significant difference between MFCd and LFCd (P = .92 and .57, respectively) and acceptable deviation based on area (87.6% overall) and step-off (96.7% overall), with no significant difference between MFCd and LFCd (P = .87 and .22, respectively). A small portion of the implant was proud (12.1% of area and 2.6% of circumference step-off height), with no significant difference between MFCd and LFCd (P = .26 and .27, respectively). A very small portion of the implant area and edge was sunk (0.3% of area and 0.6% of circumference), with no significant difference between MFCd and LFCd (P = .29 and .86, respectively).Conclusion/clinical relevanceThe achievement of excellent OCA surface match with an MFCd or LFCd graft into the common MFCr site suggests that nonorthotopic LFC OCAs are acceptable graft options for MFC defects.

ObjectiveTo describe and apply a semi-quantitative MRI scoring system for multi-feature analysis of cartilage defect repair in the knee by osteochondral allografts, and to correlate this scoring system with histopathologic, micro-computed tomography (μCT), and biomechanical reference standards using a goat repair model.DesignFourteen adult goats had two osteochondral allografts implanted into each knee: one in the medial femoral condyle (MFC) and one in the lateral trochlea (LT). At 12 months, goats were euthanized and MRI was performed. Two blinded radiologists independently rated nine primary features for each graft, including cartilage signal, fill, edge integration, surface congruity, calcified cartilage integrity, subchondral bone plate congruity, subchondral bone marrow signal, osseous integration, and presence of cystic changes. Four ancillary features of the joint were also evaluated, including opposing cartilage, meniscal tears, synovitis, and fat-pad scarring. Comparison was made with histological and μCT reference standards as well as biomechanical measures. Interobserver agreement and agreement with reference standards was assessed. Cohen's kappa, Spearman's correlation, and Kruskal-Wallis tests were used as appropriate.ResultsThere was substantial agreement (κ>0.6, p

Background: Fresh osteochondral allograft (OCA) transplantation is a viable treatment option for osteochondral defects of the talus. However, sufficient data are not available on patients' participation in sports or recreational activities after the procedure. Purpose: To assess whether patients undergoing OCA transplantation of the talus participated in sports or recreational activities postoperatively. Study Design: Case series; level of evidence, 4. Methods: A total of 36 ankles in 34 patients underwent OCA transplantation of the talus. At a mean follow-up of 9.2 years, information on participation in sports or recreational activities pre- and postoperatively was obtained, as well as postoperative pain, function, and satisfaction. Results: The mean age at the time of surgery was 36.1 years (range, 20.5-57.7 years), and 50% of patients were men. The mean graft size was 3.6 cm2 (range, 1-7.2 cm2) or 41.1% of the talar dome. Before the injury, 63.9% of patients (23/36 ankles) reported being highly competitive athletes or well trained and frequently sporting; 36.1% of patients (13/36 ankles) reported sometimes sporting or were nonsporting. Also, 66.7% of patients (24/36 ankles) were able to participate in sports or recreational activities after OCA transplantation and 50% (18/36 ankles) were still participating in sports or recreational activities at the latest follow-up. In a subset of well-trained or highly competitive athletes, 73.9% (17/23 ankles) were able to return to sports or recreational activities at any point after OCA transplantation, and 65.2% (15/23 ankles) were still participating at the latest follow-up. Further surgery occurred in 16.7% of patients (6/36 ankles). Graft survivorship was 94.3% at 5 years and 85.3% at 10 years. There was a significant improvement in the mean Olerud-Molander Ankle Scores, and the mean Foot and Ankle Ability Measure scores were high postoperatively. Moreover, 79.4% of patients (27/34 ankles) were either satisfied or extremely satisfied with the allograft surgery. Conclusion: Fresh OCA transplantation is a reasonable surgical option for osteochondral defects of the talus for young, active patients who have failed previous operative management or have massive defects. [ABSTRACT FROM AUTHOR]

Background: Studies have demonstrated the acceptability of using a contralateral nonorthotopic lateral femoral condyle (LFC) graft for a circular medial femoral condyle (MFC) osteochondral defect up to 20 to 25 mm in diameter. Larger oblong defects can now be managed using either overlapping circle grafts or a single oblong-shaped osteochondral allograft (OCA). Purpose: To determine if an oblong contralateral nonorthotopic LFC OCA can attain an acceptable surface contour match compared with an oblong ipsilateral MFC OCA or an overlapping circle technique for large oblong defects of the MFC. Study Design: Controlled laboratory study. Methods: A total of 120 fresh-frozen human femoral condyles were matched by tibial width into 30 groups of 4 condyles (1 recipient MFC, 3 donor condyles). The recipient MFC was initially imaged using nano–computed tomography (nano-CT). A 17 × 36–mm oblong defect was created in the recipient MFC. Overall, 3 donor groups were formed: MFC oblong, LFC nonorthotopic oblong, LFC or MFC overlapping circles. After each transplant, the recipient condyle underwent nano-CT and was digitally reconstructed, which was superimposed on the initial nano-CT scan of the native recipient condyle. Dragonfly 3D software was used to determine the root mean square (RMS) of both the surface height deviation and the circumferential step-off height deviation between the native and donor cartilage surfaces for each graft. Results: RMS surface height deviations were as follows: 0.59 mm for MFC oblong grafts, 0.58 mm for LFC oblong grafts, and 0.78 mm for overlapping circle grafts. The MFC and LFC oblong grafts had significantly less surface height deviation than the overlapping circle grafts (P =.004 and P =.002, respectively). RMS step-off height deviations were as follows: 0.68 mm for MFC oblong grafts, 0.70 mm for LFC oblong grafts, and 0.85 mm for overlapping circle grafts. The MFC and LFC oblong grafts had significantly less step-off height deviation than the overlapping circle grafts (P <.001 and P =.002, respectively). The majority of this difference was on the medial segment of the overlapping circle grafts. Conclusion: Oblong ipsilateral MFC OCAs and oblong contralateral nonorthotopic LFC OCAs produced a significantly better surface contour match to the native MFC than overlapping circle grafts for oblong defects 17 × 36 mm in size. Clinical Relevance: Size-matched contralateral nonorthotopic LFC grafts are acceptable for MFC defects, which may allow for a quicker match, earlier patient care, and less wastage of valuable donor tissue. [ABSTRACT FROM AUTHOR]