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  Medical Topics: 

  • Anterior Cruciate

  •         Ligament 
     
  • Articular cartilage

  •           Injury 
     
  •      Meniscus

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  •        Patella

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  • Degenerative Joint

  •          Disease 

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    GNYaco@aol.com 
     
       ARTICULAR   
       CARTILAGE   
           INJURY
     
     
     
     1. Definition: Articular or Hyaline cartilage covers the end of  
            the long bones and forms the joint surfaces. It is a unique  
            structure in that it can withstand enormous compressive  
            forces and create a low friction surface for the joint to  
            glide on. This complex organ is made up of cells called  
            chondrocytes and matrix composed of proteins and sugars  
            in a specific interwoven fabric. 

    2. Injury: Articular cartilage is injured when the knee joint is  
            compressed under heavy load or when angular or shear  
            forces are applied to the surface. The result is one of  
            several possible lesions...softening, fissuring, fragmenting  
            or complete removal of the cartilage covering. Symptoms  
            include pain, swelling and subsequent loss of joint function. 

            Adult articular cartilage does not repair itself. The reason  
            is that the chondrocytes have little mobility and there is no  
            blood supply to the matrix to provide healing elements. The  
            above mentioned lesions then, are more or less permanent.  

            Worse yet, they progress from softening to complete  
            destruction of the joint if left untreated. 

    TREATMENT: If there are correctable causes of the articular  
            cartilage problem, these must be addressed first: 

                  a) Loss of meniscus - early stages of cartilage damage  
            due to loss of meniscal tissue and subsequent high  
            compressive loads are addressed by meniscal allograft  
            reconstruction (see Meniscus). 
                 b) Malalignment - abnormal knee  
           alignment is corrected by distal femoral  
           or proximal tibial osteotomy. This is  
           where a wedge of  bone is surgically   
           added to or removed from the bone  
           adjacent to the knee to recreate a    
           horizontal joint line and eliminate high  
           angular stresses on the cartilage.
                  c) Instability - loss of the anterior cruciate ligament  
            (ACL) creates gliding movements in the joint and high  
            shear stress on the articular cartilage. This is treated with  
            ACL reconstruction (see Anterior Cruciate Ligament). 
             
            Once these causes are corrected, the articular cartilage  
            lesions can be addressed. Symptomatic areas of fragmented  
            or destroyed cartilage have traditionally been treated by  
            abrading or puncturing the underlying bone. These  
            techniques lead to healing with fibrocartilage which does  
            not possess the same mechanical properties as hyaline  
            cartilage and lasts only 10 to 12 months. Newer technologies 
            are aimed at repairing these defects with tissue that     
            reproduces the original hyaline cartilage surface. These  
            innovative treatments include:  


     
                                               Click to see enlarged picture 
                 a) Autologous Chondrocyte Implantation (carticel) - if a  
             full thickness defect in the articular cartilage (>2 cm.  
            diameter) is found in a weight bearing area of the femoral  
            condyle, a biopsy is obtained arthroscopically from a  
            non-functional area of the same knee. This sample is sent to  
            a laboratory where the cartilage cells are manipulated to  
            replicate and produce hyaline like matrix. These  
            "stimulated" cells are suspended in a liquid medium and  
            then injected into the prepared defect during the second  
            (open) surgery. The defect will subsequently fill with this  
            new cartilage and the patients symptoms will improve as  
            the cartilage matures over 1 year. The cost of this complex  
            laboratory process is over $11,000.00...however this is more  
            then justified if it saves a young, healthy, productive person  
            from prolonged disabling knee pain, slow deterioration of  
            the joint and ultimately a knee replacement at a relatively  
            young age. This procedure is only recommended for  
            patients who are between the ages of 15 and 55 and have an  
            otherwise normal knee (alignment, meniscus, and ligament). 
     
            Dr. Yacobucci has flown to Sweden to receive special  
            training in this technique from the surgeon who pioneered  
            this operation. He has performed over 20 of these 
            surgeries and is actively involoved in clinical research and
            teaching as it pertains to this complex procedure.  


                                          ---- 

                 b) Osteochondral Autograph Transfer (OATS) - smaller  
             full thickness defects can be treated by transferring punch  
            grafts of bone and cartilage from a healthy non-functional  
            area in the knee into the prepared defect. The advantages  
            over carticel are this can be done during one  arthroscopic  
            procedure, and the cost is significantly less. This technique  
            is quite demanding as positioning of the grafts must be         
            precise to create a  smooth, functional articular cartilage  
            surface. There are no age limits on patient selection and the  
            condition of the remainder of the joint need not  
            be perfect. Full maturation of the graft is complete at about  
            12 weeks post-op.  

            Dr.Yacobucci has performed over 20 of these procedures  
            and has given numerous seminars about this innovative  
            operation.  
     



     
     
                          Before                                                              After 
                     c) Osteoarticular Allograft Reconstrucion - a new  
            technique of harvesting, testing and preserving bone and  
            articular cartilage from deceased human tissue donors  
            allows us to use these large (up to 4 cm. diameter) grafts to  
            fill massive femoral condyle surface defects. This is the  
            result of a patented technique developed by Cryolife      
            corporation that preserves large numbers of viable  
            chondrocytes in the grafted tissue. Advanced  
            instrumentation is used to exactly duplicate the contour of  
            the cartilage surface being repaired. A press fit secures the  
            graft at the recipient site. The cost of tissue and  
            intrumentation is $10,000 however, this procedure has the  
            potential of saving a knee joint from gradual complete  
            destruction. 

                  Dr. Yacobucci is one of only a few knee surgeons in  
            Arizona who have successfully carried out this procedure. 
             



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