Cartilage Wound Healing and Integration

The intrinsic regeneration capacity of articular cartilage following injury is limited. Partialthickness defects are not repaired and full-thickness defects are repaired with fi brocartilage. Untreated, these defects may progress to early osteoarthritis. The goal of surgical treatment of (osteo)chondral defects is to reduce symptoms, improve joint congruence by restoring the joint surface with the best possible tissue, and to prevent joint degeneration. Current clinical and experimental treatment methods, for cartilage repair and regeneration, do not result in durable and predictable restoration of the articular surface in damaged joints. An important prerequisite for durable repair of cartilage lesions is the integration of wound edges or the integration of repair tissue with the surrounding host cartilage. In the general introduction chapter (chapter 1) the morphology and molecular composition of articular cartilage is described. The incidence and natural outcome of articular cartilage defects is given as well as a short overview of current clinical and experimental surgical treatment techniques

Quality of life and health status after Girdlestone resection arthroplasty in patients with an infected total hip prosthesis

Introduction: The Girdlestone resection arthroplasty (GRA) is a salvage procedure for a recurrent or persistent prosthetic joint infection of the hip. This procedure negatively impacts the functional outcome and presumably also diminishes health status (HS) and quality of life (QOL). However, studies investigating the QOL after GRA are lacking. This cross-sectional study compares patients with a Girdlestone situation after an infected total hip prosthesis with a normative population with regard to HS and QOL. Methods: Patients with a permanent GRA were suitable to be enrolled in the study. Subjects completed the World Health Organization Quality of life (WHOQOL-BREF) and the EuroQol 5 dimension 3 level version (EQ-5D-3L). Scores were compared with data from the normal populat

Preoperative embolization in surgical treatment of long bone metastasis: A systematic literature review

Surgery of long bone metastases is associated with a significant risk of perioperative blood loss, which may necessitate blood transfusion. Successful embolization (> 70% obliteration of vascularity) can be achieved in 36-75% of cases. The reported rate of embolization-related complications is 0-9%. Three out of six level III evidence studies showed a reduction in perioperative blood loss and/orblood transfusion requirement after preoperative embolization of renal cell carcinoma metastasis in long bones; three out of six studies did not. One level III evidence study did not show a reduction in perioperative blood loss and/or transfusion requirement after preoperative embolization of hepatocellular carcinoma metastases in long bones. There were no studies found that support preoperative embolization of thyroid metastases or other frequent long bone metastases (e.g. mamma carcinoma, lung carcinoma, or prostate carcinoma). The clinical level of evidence of the studies found is low and randomized studies taking into account primary tumour, location of metastases and type of surgery are therefore desired

Pre-Treatment of Human Mesenchymal Stem Cells with Inflammatory Factors or Hypoxia Does Not Influence Migration to Osteoarthritic Cartilage and Synovium

Background: Mesenchymal stem cells (MSCs) are promising candidates as a cell-based therapy for osteoarthritis (OA), although current results are modest. Pre-treatment of MSCs before application might improve their therapeutic efficacy. Hypothesis: Pre-treatment of MSCs with inflammatory factors or hypoxia will improve their migration and adhesion capacities toward OA-affected tissues. Study Design: Controlled laboratory study. Methods: We used real-time polymerase chain reaction to determine the effects of different fetal calf serum (FCS) batches, platelet lysate (PL), hypoxia, inflammatory factors, factors secreted by OA tissues, and OA synovial fluid (SF) on the expression of 12 genes encoding chemokine or adhesion receptors. Migration of MSCs toward factors secreted by OA tissues was studied in vitro, and attachment of injected MSCs was evaluated in vivo in healthy and OA knees of male Wistar rats. Results: Different FCS batches, PL, or hypoxia did not influence the expression of the migration and adhesion receptor genes. Exposure to inflammatory factors altered the expression of CCR1, CCR4, CD44, PDGFRα, and PDGFRβ. MSCs migrated toward factors secreted by OA tissues in vitro. Neither pre-treatment with inflammatory factors nor the presence of OA influenced MSC migration in vitro or adhesion in vivo. Conclusion: Factors secreted by OA tissues increase MSC migration in vitro. In vivo, no difference in MSC adhesion was found between OA and healthy knees. Pre-treatment with inflammatory factors influenced the expression of migration and adhesion receptors of MSCs but not their migration in vitro or adhesion in vivo. Clinical Relevance: To improve the therapeutic capacity of intra-articular injection of MSCs, they need to remain intra-articular for a longer period of time. Pre-treatment of MSCs with hypoxia or inflammatory factors did not increase the migration or adhesion capacity of MSCs and will therefore not likely prolong their intra-articular longevity. Alternative approaches to prolong the intra-articular presence of MSCs should be developed to increase the therapeutic effect of MSCs in OA

Adverse events and survival after closing- and opening-wedge high tibial osteotomy: a comparative study of 412 patients

Purpose: Varus medial knee osteoarthritis (OA) can be treated with a closing-wedge (CW) or opening-wedge (OW) high tibial osteotomy (HTO). Little is known about the adverse event (AE) rate of these techniques. The purpose of this study was to examine the AE rate and survival rate of a consecutive series of 412 patients undergoing CW- or OW-HTO. Methods: Medical records were retrospectively screened, and all patients who underwent HTO from 1993 to 2012 at the Erasmus University Medical Centre were assessed with a self-administered questionnaire. Patients filled in the intermittent and constant osteoarthritis pain score, knee injury and osteoarthritis outcome score, and a general questionnaire focusing on AE. Results: Medical records of 412 patients (354 CW- and 112 OW-HTOs) were screened. Of the 358 eligible patients, 291 (81 %) returned their questionnaire. A total of 80 AE (17 %) were found in 466 osteotomies. In the CW-group, 47 (13 %) serious adverse events (SAE) and 2 (0.6 %) AE were found. In the OW-group, 17 (15 %) SAE and 14 (13 %) AE were found. The most common AE was in 14 (4 %) patients of the CW-group sensory palsy of the common peroneal nerve. The most common AE in the OW-group was persistent pain at the iliac crest [11 (9.8 %) patients]. Hardware was removed in 48 % of the CW-osteotomies and 71 % of the OW-osteotomies (p < 0.05). The probability of survival was 75 % after 10 years in the CW-group versus 90 % in the OW-group (p < 0.05). In both groups, an equal number of patients were “in need for prosthesis” according to OARSI criteria. Conclusion: OW-HTO was associated with more AE than CW-HTO. OW-HTO resulted in better survival than CW-HTO. However, in both groups an equal number of patients were in need for prosthesis. Level of evidence: Retrospective comparative study, Level III

Effect of arthritic synovial fluids on the expression of immunomodulatory factors by mesenchymal stem cells: An explorative in vitro study

Background:In diseased joints, the catabolic environment results in progressive joint damage. Mesenchymal stem cells (MSCs) can have immunomodulatory effects by secreting anti-inflammatory factors. To exert these effects, MSCs need to be triggered by proinflammatory cytokines. To explore the potential of MSCs as a treatment for diseased joints, we studied the effect of synovial fluid (SF) from donors with different joint diseases and donors without joint pathology on the immunomodulatory capacities of human MSCs in vitro. We hypothesized that SF of diseased joints influences the immunomodulatory effects of MSCs. Materials and Methods: MSCs were cultured in medium with SF of six osteoarthritis (OA) or six rheumatoid arthritis (RA) donors and three donors without joint pathology were used as control. Gene expressions of IL-6, HGF, TNFa, TGFb1, and indoleamine 2,3-dioxygenase (IDO) were analyzed. L-kynurenine concentration in conditioned medium (CM) by MSCs with SF was determined as a measure of IDO activity by MSCs. Furthermore, the effect of CM with SF on proliferation of activated lymphocytes was analyzed. Results: Addition of SF significantly up-regulated the mRNA expression of IL-6 and IDO in MSCs. SF(OA) induced significantly higher expression of IDO than SF(control), although no difference in IDO activity of the MSCs could be shown with a L-kynurenine assay. Medium conditioned by MSCs with SF(OA or RA) suppressed activated lymphocyte proliferation in vitro more than medium conditioned by MSCs without SF or with SF(control). Discussion: SF can influence the expression of genes involved in immunomodulation by MSCs and the effect on lymphocyte proliferation. We found indications for disease-specific differences between SFs but the variation between donors, even within one disease group was high. These data warrant further research to examine the potential application of MSC therapy in arthritic joints

The effectiveness of high molecular weight hyaluronic acid for knee osteoarthritis in patients in the working age: a randomised controlled trial

Background: High molecular weight (HMW) hyaluronic acid (HA) is a treatment option for knee osteoarthritis (OA). The efficacy of HMW-HA in knee OA is investigated extensively, but the effectiveness in patients in the working age is unknown. Nevertheless, the number knee OA patients in the working age is increasing. Surgical treatment options are less eligible in these patients and productivity losses are high. In this study the effectiveness of intraarticular HMW-HA added to regular non-surgical usual care in everyday clinical practice (UC) compared to UC over 52 weeks in symptomatic knee OA patients in the working age was investigated. Methods: In this open labelled randomized controlled trial, subjects aged between 18 and 65 years with symptomatic knee OA (Kellgren and Lawrence I-III) were enrolled and randomized to UC + 3 weekly injections with HMW-HA (intervention) or UC only (control). The primary outcome was the between group difference in responders to therapy according to OMERACT-OARSI criteria after 52 weeks. These criteria include the domains pain, knee related function and patient’s global assessment (PGA). Function was evaluated with the KOOS questionnaire. Pain was assessed with the Numeric Rating Scale. Secondary outcome comprised the between group difference on the individual responder domains, as analysed with a random effects model. Odds Ratios (OR) were calculated by logistic regression analysis. Sensitivity analyses were performed. Results: In total, 156 subjects were included (intervention group 77, control group 79). Subjects in the intervention group (HMW-HA + UC) were more often responder compared to the controls (UC). Depending on whether pain during rest or pain during activity was included in the responder domains, 57.1% versus 34.2% (p = 0.006) and 54.5% versus 34.2% (p = 0.015) was responder to therapy respectively. The results of the secondary

MSC encapsulation in alginate microcapsules prolongs survival after intra-articular injection, a longitudinal in vivo cell and bead integrity tracking study

Mesenchymal stem cells (MSC) are promising candidates for use as a biological therapeutic. Since locally injected MSC disappear within a few weeks, we hypothesize that efficacy of MSC can be enhanced by prolonging their presence. Previously, encapsulation in alginate was suggested as a suitable approach for this purpose. We found no differences between the two alginate types, alginate high in mannuronic acid (High M) and alginate high in guluronic acid (High G), regarding MSC viability, MSC immunomodulatory capability, or retention of capsule integrity after subcutaneous implantation in immune competent rats. High G proved to be more suitable for production of injectable beads. Firefly luciferase-expressing rat MSC were used to track MSC viability. Encapsulation in high G alginate prolonged the presence of metabolically active allogenic MSC in immune competent rats with monoiodoacetate-induced osteoarthritis for at least 8 weeks. Encapsulation of human MSC for local treatment by intra-articular injection did not significantly influence the effect on pain, synovial inflammation, or cartilage damage in this disease model. MSC encapsulation in alginate allows for an injectable approach which prolongs the presence of viable cells subcutaneously or in an osteoarthritic joint. Further fine tuning of alginate formulation and effective dosage for might be required in order to improve therapeutic efficacy depending on the target disease. [Figure not available: see fulltext.]

Intra-articular Injections of Platelet-Rich Plasma Releasate Reduce Pain and Synovial Inflammation in a Mouse Model of Osteoarthritis

Background: Osteoarthritis (OA) is a degenerative joint disease leading to pain and disability for which no curative treatment exists. A promising biological treatment for OA is intra-articular administration of platelet-rich plasma (PRP). PRP injections in OA joints can relieve pain, although the exact working mechanism is unclear. Purpose: To examine the effects of PRP releasate (PRPr) on pain, cartilage damage, and synovial inflammation in a mouse OA model. Study Design: Controlled laboratory study. Methods: OA was induced unilaterally in the knees of male mice (n = 36) by 2 intra-articular injections of collagenase at days –7 and –5. At day 0, pain was measured by registering weight distribution on the hindlimbs, after which mice were randomly divided into 2 groups. Mice received 3 intra-articular injections of PRP or saline in the affected knee. Seven mice per group were euthanized at day 5 for assessment of early synovial inflammation and cartilage damage. Pain in the remaining mice was registered for a total of 3 weeks. These mice were euthanized at day 21 for assessment of cartilage damage and synovial inflammation on histological evaluation. Antibodies against iNOS, CD163, and CD206 were used to identify different subtypes of macrophages in the synovial membrane. Results: Mice in the PRPr group increased the distribution of weight on the affected joint in 2 consecutive weeks after the start of the treatment (P <.05), whereas mice in the saline group did not. At day 21, PRPr-injected knees had a thinner synovial membrane (P <.05) and a trend toward less cartilage damage in the lateral joint compartment (P =.053) than saline-injected knees. OA knees treated with saline showed less anti-inflammatory (CD206+ and CD163+) cells at day 5 than healthy knees, an observation that was not made in the PRPr-treated group. A higher level of pain at day 7 was associated with a thicker synovial membrane at day 21. The presence of CD206+ cells was negatively associated with synovial membrane thickness. Conclusion: In a murine OA model, multiple PRPr injections reduced pain and synovial thickness, possibly through modulation of macrophage subtypes. Clinical Relevance: PRPr injections in early OA or shortly after joint trauma can reduce pain and synovial inflammation and may inhibit OA development in patients

Quantitative in vivo CT arthrography of the human osteoarthritic knee to estimate cartilage sulphated glycosaminoglycan content: Correlation with ex-vivo reference standards

Objective: Recently, computed tomography arthrography (CTa) was introduced as quantitative imaging biomarker to estimate cartilage sulphated glycosaminoglycan (sGAG) content in human cadaveric knees. Our aim was to assess the correlation between in vivo CTa in human osteoarthritis (OA) knees and ex vivo reference standards for sGAG and collagen content. Design: In this prospective observational study 11 knee OA patients underwent CTa before total knee replacement (TKR). Cartilage X-ray attenuation was determined in six cartilage regions. Femoral and tibial cartilage specimens harvested during TKR were re-scanned using equilibrium partitioning of an ionic contrast agent with micro-CT (EPIC-μCT), which served as reference standard for sGAG. Next, cartilage sGAG and collagen content were determined using dimethylmethylene blue (DMMB) and hydroxyproline assays. The correlation between CTa X-ray attenuation, EPIC-μCT X-ray attenuation, sGAG content and collagen content was assessed. Results: CTa X-ray attenuation correlated well with EPIC-μCT (r = 0.76, 95% credibility interval (95%CI) 0.64 to 0.85). CTa correlated moderately with the DMMB assay (sGAG content) (r = -0.66, 95%CI -0.87 to -0.49) and to lesser extent with the hydroxyproline assay (collagen content) (r = -0.56, 95%CI -0.70 to -0.36). Conclusions: Outcomes of in vivo CTa in human OA knees correlate well with sGAG content. Outcomes of CTa also slightly correlate with cartilage collagen content. Since outcomes of CTa are mainly sGAG dependent and despite the fact that further validation using hyaline cartilage of other joints with different biochemical composition should be conducted, CTa may be suitable as quantitative imaging biomarker to estimate cartilage sGAG content in future clinical OA research