Cartilage Restoration Review
Learn more about cartilage restoration and schedule a consultation with Dr. Geoffrey Van Thiel
Introduction to Cartilage Restoration
Articular cartilage can experience both acute injury and chronic degeneration. These processes vary with patient age, pathologic insult, natural history, and future prognosis. There is often an overlap between the two; therefore, injury or degeneration of articular cartilage should be thought of as a spectrum rather than a discreet mechanism. However, regardless of the pathologic insult, articular cartilage has a limited capacity for repair. This is most likely due to a multitude of factors. Poor vascular supply requires interstitial fluid to provide the necessary nutrients via diffusion. To further complicate the repair process, chondrocytes have low mitotic activity and a low turnover rate. Lastly, cartilage has a deficiency in the capacity for an undifferentiated cell population to respond to the damage.
The natural history of isolated chondral and osteochondral defects is unknown. However, clinical experience suggests that, when left untreated, these lesions do not heal and may progress to symptomatic degeneration of the joint. Furthermore, lesion progression may be dependent on size, location, subchondral bone, age of patient, limb alignment, BMI and joint stability. The available natural history studies suffer from small patient populations with confounding coexisting pathology. To further complicate the matter, some studies have suggested that radiographic deterioration may be present, but this is unrelated to the functional scores. In our clinical experience, early surgical intervention for symptomatic lesions is often suggested in an effort to restore normal joint congruity and pressure distribution and prevent further injury. However, the surgeon must ensure that the expectations of the patient and the goals of surgical treatment are aligned. The most predictable goal with cartilage restoration surgery is to provide pain relief and improve joint function, thus allowing patients to comfortably perform activities of daily living. These patients do also have the potential to attain or return to a higher level of sport/activity, but these outcomes are significantly more variable.
Multiple algorithms have been described in an effort to simplify the treatment of cartilage lesions. These provide an important dynamic conceptual framework that creates consistent management of patient pathology. However, these algorithms must be flexible as new concepts and information arise. In general, cartilage restoration surgical options can be grouped into three categories: palliative (arthroscopic débridement and lavage), reparative (marrow stimulation techniques), and restorative (osteochondral grafting and autologous chondrocyte implantation). All of these techniques have been reported to improve the clinical status as compared with the preoperative state. Thus, the appropriate treatment for any given cartilage lesion is patient-specific. Important considerations include; the size and location of the lesion, the physical demands of the patient, and the treatment history. A realistic and comprehensive understanding of the patient’s goals is critical to any decision regarding how to treat a symptomatic chondral defect. In keeping with these principles, the treatment algorithm consists of a graduated surgical plan. The least destructive and least invasive treatment option necessary to alleviate the symptoms and restore joint function is performed first. The more extensive treatments are reserved for potential salvage operations later.