Patient Information - Knee Arthritis

Background

Knee pain is all too common in men and woman of all ages. It is thought that at least 4 million adults in the UK suffer from knee pain with more than 90,000 knee replacements and with 300,000 knee arthroscopies in the UK considerable efforts are in place to treat these conditions. In the USA there are more than 15 million clinical visits by sufferers of knee pain with more than 5000,000 knee replacements and many more arthroscopies. Despite the various treatment options, symptomatic articular cartilage defects continue to represent a therapeutic challenge for knee surgeons (Fabrio Valerio Sciaretta 2013) It is a well known fact that correct knee joint function depends on excellent lubrication and uniform distribution of loads in different compartments. Physicians have known for over 250 years that articular cartilage damage is a troublesome thing and once destroyed, it is not repaired. Chondral and osteochondral lesions continue to present ongoing challenges for knee surgeons.

Arthritic knee joint

Pathophysiology

Despite its relatively unremarkable appearance articular cartilage has a unique ability to provide low-friction surface and survive repetitive loading in compression, shear, and tension for many decades. It is avascular, aneural, lymphatic, and contains a single cell type, the chondrocyte. Its lack of vascularity, high matrix-to-cell ratio, and a lack of a local undifferentiated cell pool leads to its limited capacity to regenerate following injury.

Patient Evaluation

Cartilage injuries can occur in isolation or in association with other inter-articular pathology. The accurate diagnosis of a symptomatic focal chondral defect requires that the evaluator maintain a high index of suspicion for this pathologic entity, especially in the presence of accompanying conditions such as meniscal or ligament tears. Symptoms may be subtle but often include localized pain, catching, swelling, and giving-way. A thorough history should elicit the mechanism of the injury, previous injuries, and symptom-provoking activities. A complete examination is essential to evaluate for concomitant pathology that would alter the treatment plan.

Knee joint diagram

Nonsurgical Management

Nonsurgical management is largely ineffective in symptomatic patients and should be reserved for relatively low-demand patients, patients wishing to avoid or delay surgery, and patients with advance, degenerative osteoarthritis considered inappropriate for articular cartilage restoration procedures. Treatment options include nonsteroidal anti-inflammatory drugs (NSAIDs), judicious use of corticosteroid injections, and/or use of oral or injectable chondroprotective agents. Alternatives include; activity modification with avoidance of high-impact activities; physical therapy focusing on muscle strengthening and hamstring flexibility; and use of a knee sleeve or an uploader to improve proprioception or unload diseased cartilage, respectively.

Although the natural history of a focal chondral lesion is poorly understood, the symptomatic lesion is likely to lead to disease progression, which would make future surgical treatment options more complicated. When surgical intervention is indicated a clear definition of lesion size, depth and location is required to determine the procedure of choice. Concomitant management of associated conditions such as malalignment, ligament insufficiency, and/or meniscal injury is essential for a successful outcome.

Surgical Management

The principal goals for surgical management of the symptomatic chondral defect are to reduce symtoms, improve joint congruence by restoring the joint surface with the most normal tissue (i.e. hyaline cartilage) possible, and to prevent additional cartilage deterioration. Although the need for surgical management is based on the patient’s history, physical examination, and diagnostic studies, only knee arthoscopy will provide definitive information regarding the lesion’s characteristics (i.e. location, size, depth, degree of containment) and associated injuries (ligamentous and/or meniscal).

Cartiva® SCI

Cartiva® SCI can offer the following benefits to patients:

  • Quick surgical procedure
  • Simple surgical procedure for implantation
  • No replacement of opposing articular surface
  • Does not require healthy tissue removal
  • Patient is immediately weight bearing post surgery
  • Short rehabilitation programme

Cartiva Synthetic Cartilage Implant (SCI) is a revolutionary implant that is designed to replace the damaged cartilage surface. Cartiva SCI is made from polyvinyl alchohol (PVA), a material that has been used in a number of medical device applications for more than 20 years. Through a proprietary manufacturing process, Cartiva SCI is designed to mimic the biochemical and other physical properties of natural cartilage. In a quick and easy procedure, the damaged cartilage is cored out and repaced with a press-fit Cartiva SCI implant.

Since 2002, Cartiva SCI has been successfully used worldwide for the treatment of symptomatic articular cartilage defects of the knee. Cartiva SCI is approved and currently available for sale in Europe, Canada and South America.

Single-Arm Clinical Study

Twenty-five patients were treated in a single site study in Rome, Italy in order to evaluate the effectiveness of Cartiva SCI in the treatment of Grade III and IV focal chondral or osteochondral defects of the knee. Of the 25 patients (one of whom received bilateral treatment) follow-up was obtained on 18 patients, with a mean follow up of 68.4 months and a range of 38-96 months.

The study findings:

  • 17-19 knees showed significant improvement over pre-operative values of IKDC* scores (at the last follow-up) with an average (SE) increase of 43.27 (5.2543) points (p<0.001)
  • Nearly half (47.4%) of patients had an improvement of more than 50 points in theor IKDC score. Individual change from pre-operative scores ranged from a slight loss of 4.60 to a gain of 71.27 points.
  • Follow up MRI images revealed normal healing process without any signs of osteolysis or wear
  • 85% of patients indicated improvement after the procedure and were satisfied with the results of the procedure (at the last follow-up)

* IKDC (The International Knee Documentation Committee) score: a method of measuring the function of the knee