Treatment of osteochondral lesions in the knee using a cell-free scaffold.

The treatment of osteochondral lesions is of great interest to orthopaedic surgeons because most lesions do not heal spontaneously. We present the short-term clinical outcome and MRI findings of a cell-free scaffold used for the treatment of these lesions in the knee. A total of 38 patients were prospectively evaluated clinically for two years following treatment with an osteochondral nanostructured biomimetic scaffold. There were 23 men and 15 women; the mean age of the patients was 30.5 years (15 to 64). Clinical outcome was assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Tegner activity scale and a Visual Analgue scale for pain. MRI data were analysed based on the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scoring system at three, 12 and 24 months post-operatively. There was a continuous significant clinical improvement after surgery. In two patients, the scaffold treatment failed (5.3%) There was a statistically significant improvement in the MOCART precentage scores. The repair tissue filled most of the defect sufficiently. We found subchondral laminar changes in all patients. Intralesional osteophytes were found in two patients (5.3%). We conclude that this one-step scaffold-based technique can be used for osteochondral repair. The surgical technique is straightforward, and the clinical results are promising. The MRI aspects of the repair tissue continue to evolve during the first two years after surgery. However, the subchondral laminar and bone changes are a concern.

Meniscal transplantation: still experimental surgery? A review.

INTRODUCTION: The objective of this review is to give a state of affairs of meniscal transplantation, with the accent on preservation and surgical techniques. MATERIALS AND METHODS: All articles were selected by performing a search on the literature by using relevant keywords. The most relevant articles were selected with close attention to the publication date. RESULTS: When a meniscal tear is diagnosed, suture can be an option in the vascular zone, whereas the more frequently affected avascular zone heals poorly. A meniscectomy however is not without consequences, wherefore meniscal transplantation can be seen as a therapeutic option for pain reduction and improvement of function when the meniscus is lost. The meniscal scaffold, allograft and autograft can be currently withheld as possible grafts, where the meniscal scaffolds hold great promise as an alternative to the allograft. Various fixation techniques are therefore developed, where viable, deep frozen as well as cryopreservated allografts seem to give the most promising short term results. The transplantation can be performed using an open as well as an arthroscopic technique, using soft tissue fixation, bone plugs or blocks. De primacy of one technique can't be proven. In general meniscal transplantation can be considered as an acceptable procedure. DISCUSSION: Since the outcomes of different studies are difficult to compare, an attempt should be made to limit new studies to the comparison of one aspect. We can conclude that larger, more comparative randomised controlled long-term studies are necessary to resolve which techniques can give the best long-term results.

First insights into human acetabular labrum cell metabolism.

OBJECTIVE: Hip labrum pathology has only begun to emerge as a significant source of groin pain in the last decade since the development of hip arthroscopy. Few data are available on the anatomy, histology and function of this structure. Moreover, no metabolic data exist at cellular level. The aim of this study was to characterize extracellular matrix (ECM) genes and pro-inflammatory mediators expressed by these cells. METHODS: Isolated human acetabular labrum cells were cultured in alginate beads for 10 days and additionally stimulated with interleukin (IL)-1 for 24 h. Gene expression levels and secretion of different ECM genes, enzymes and cytokines were examined by quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA) to assess the metabolic characteristics of labrum cells. Articular chondrocytes and meniscus cells served as controls. RESULTS: Labrum cells expressed high levels of COL1A1 and low levels of COL2A1, aggrecan and SOX-9 compared to chondrocytes. However, COL2A1 was more expressed by labrum cells than by meniscus cells. The expression of matrix metalloproteinase (MMP)-1/-2/-9, ADAMTS-4 and IL-6 was significantly higher in labrum cells than in chondrocytes. IL-1 suppressed the ECM gene expression levels of labrum cells, but increased the expression levels and release of MMP-1/-3/-9/-13 and ADAMTS-4 and IL-6 by these cells. Remarkably, MMP-9 was only significantly upregulated in acetabular labrum cells. CONCLUSIONS: The findings in this study demonstrated that the acetabular labrum is populated with unique highly active fibrochondrocyte-like cells. These cells are capable of expressing and releasing pro-inflammatory enzymes and cytokines and react to a pro-inflammatory stimulus. In this way, they contribute obviously to disturbed tissue function in hip labrum pathology.

The combination of microfracture and a cell-free polymer-based implant immersed with autologous serum for cartilage defect coverage.

PURPOSE: The purpose of this short-term pilot study was to determine the clinical and MRI outcome of a combination of microfracture with a cell-free polymer-based matrix for the treatment of cartilage defects in the knee. METHODS: The technique was used for treatment of symptomatic cartilage defects in the knee. Five patients were prospectively evaluated during 2 years with use of the Knee injury and Osteoarthritis Outcome Score (KOOS), the Tegner activity scale and the visual analog scale (VAS). MRI data were analyzed based on the original and modified MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) scoring system at 6, 12 and 24 months of follow-up. RESULTS: A gradual clinical improvement was observed during the follow-up. Adverse reactions to the matrix were not observed. The scaffold was firmly fixed with the use of bioresorbable pins. Both MOCART scoring systems revealed no significant deterioration or improvement in the repair tissue during the follow-up period. However, the majority of the patients exhibited subchondral lamina and bone changes. The formation of an intralesional osteophyte was observed in one case. CONCLUSIONS: The key finding in this study was that this procedure is safe for the treatment of cartilage defects in the knee. The patients showed a gradual clinical improvement postoperatively. Sixty percent (3/5) of the defects were adequately (complete or hypertrophic) filled with repair tissue at 2 years of follow-up. LEVEL OF EVIDENCE: IV.

Short-term outcome of the second generation characterized chondrocyte implantation for the treatment of cartilage lesions in the knee.

PURPOSE: To evaluate short-term clinical and MRI outcome of the second generation characterized chondrocyte implantation (CCI) for the treatment of cartilage defects in the knee. METHODS: Thirty-two patients aged 15-51 years with single International Cartilage Repair Society (ICRS) grade III/IV symptomatic cartilage defects of different locations in the knee were treated with CCI using a synthetic collagen I/III membrane to cover the defect. Clinical outcome was measured over 36 months by the Knee injury and Osteoarthritis Outcome Score (KOOS) and Visual Analogue Scale (VAS) for pain. Serial magnetic resonance imaging (MRI) scans of 22 patients were scored using the original and modified Magnetic resonance Observation of Cartilage Repair Tissue (MOCART) system. RESULTS: The patients included in this study showed a significant gradual clinical improvement after CCI. The MRI findings of this pilot study were considered to be promising. No signs of deterioration were observed. A complete or hypertrophic filling was observed in 76.5% of the cases at 24 months of follow-up. No preventive effect of an avital membrane on the occurrence of hypertrophic repair tissue was observed on MRI. Three failures were observed among the 32 patients until now (9.4%). CONCLUSIONS: This investigation provided useful information on the efficacy of this treatment. The short-term clinical and MRI outcome are promising. Large-scale and long-term trials are mandatory to confirm the results and the reliability of this procedure. LEVEL OF EVIDENCE: IV.

Autologous matrix-induced chondrogenesis combined with platelet-rich plasma gel: technical description and a five pilot patients report.

PURPOSE: This pilot study was designed to describe the technical details and to present the preliminary outcome of autologous matrix-induced chondrogenesis (AMIC) combined with platelet-rich plasma gel, the so called AMIC plus technique, for the treatment of patellar cartilage defects in the knee. METHODS: The AMIC plus technique was used for the treatment of (osteo) chondral patellar lesions in the knee. The surgical technique is extensively described. Five patients were clinically prospectively evaluated during 2 years. MRI data were analysed based on the original MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) and modified MOCART scoring system. RESULTS: A clinical improvement became apparent after 24 months of follow-up. Both MOCART scoring systems revealed no significant deterioration or improvement of the repair tissue between one and 2 years of follow-up. However, all cases showed subchondral lamina and bone changes. The formation of intralesional osteophytes was observed in 3 of the 5 patients during the 2 years of follow-up. CONCLUSIONS: AMIC plus is feasible for the treatment of symptomatic patellar cartilage defects and resulted in a clinical improvement in all patients. The favourable clinical outcome of the AMIC plus technique was not confirmed by the MRI findings. LEVEL OF EVIDENCE: IV.

MRI evaluation of a new scaffold-based allogenic chondrocyte implantation for cartilage repair.

AIM: The present study was designed to evaluate the implantation of alginate beads containing human mature allogenic chondrocytes for the treatment of symptomatic cartilage defects of the knee. MRI was used for the morphological analysis of cartilage repair. The correlation between MRI findings and clinical outcome was also studied. METHODS: A biodegradable, alginate-based biocompatible scaffold containing human mature allogenic chondrocytes was used for the treatment of symptomatic chondral and osteochondral lesions in the knee. Twenty-one patients were prospectively evaluated with use of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Visual Analogue Scale (VAS) for pain preoperatively and at 3, 6, 9 and 12 months of follow-up. Of the 21 patients, 12 had consented to follow the postoperative MRI evaluation protocol. MRI data were analyzed based on the original MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) and modified MOCART scoring system. The correlation between the clinical outcome and MRI findings was evaluated. RESULTS: A statistically significant clinical improvement became apparent after 6 months and patients continued to improve during the 12 months of follow-up. One of the two MRI scoring systems that were used, showed a statistically significant deterioration of the repair tissue at 1 year of follow-up. Twelve months after the operation complete filling or hypertrophy was found in 41.6%. Bone-marrow edema and effusion were seen in 41.7% and 25% of the study patients, respectively. We did not find a consistent correlation between the MRI criteria and the clinical results. DISCUSSION: The present study confirmed the primary role of MRI in the evaluation of cartilage repair. Two MOCART-based scoring systems were used in a longitudinal fashion and allowed a practical and morphological evaluation of the repair tissue. However, the correlation between clinical outcome and MRI findings was poor. Further validation of these scoring systems is mandatory. The promising short-term clinical outcome of the allogenic chondrocytes/alginate beads implantation was not confirmed by the short-term MRI findings.

Extraosseous variations of temperature during polymerization of acrylic cement in hip arthroplasties.

In order to evaluate the estraosseous temperature variations during polymerization of acrylic cement being used in hip arthroplasty, measurements were taken on the anterior aspect of the upper part of the femur and also in the ipsilateral iliac vein. No variations were observed in the blood stream. On the external surface of the upper femur, the greatest variations were of the order of 3 degrees C. The significance of these findings is discussed.