Cartilage restoration, part 1: basic science, historical perspective, patient evaluation, and treatment options.

Surgical procedures designed to treat focal chondral lesions are evolving and are supported by basic science principles of cartilage physiology and known responses to injury. Selecting the proper treatment algorithm for a particular patient depends on careful patient evaluation, including the recognition of comorbidities such as ligamentous instability, deficient menisci, or malalignment of the mechanical limb axis or extensor mechanism. These comorbidities may need to be treated in conjunction with symptomatic chondral injuries to provide a mutually beneficial effect. A central tenet of cartilage restoration is to leave future treatment options available should they become necessary. In this article (part 1), the authors review the basic science of chondral injuries, the historical perspective of the available surgical options, and present guidelines for patient evaluation and treatment.