Concealed knee cartilage lesions: is arthroscopic probing therapeutic?

We report on 34 knee arthroscopic procedures (of 976 knee procedures performed during a 2-year period) performed on patients with chronic knee symptoms or symptoms mimicking a torn meniscus. All patients had deep articular cartilage lesions over which the superficial cartilage appeared normal. These lesions were not diagnosed on radiographs, magnetic resonance imaging, or bone scintigraphy. Only careful arthroscopic probing disclosed the deep cartilage separation. The treatment consisted of cartilage puncturing with a probe, which in 14 cases led to the evacuation of blood. This simple technique produced resolution of symptoms in 30 (88.2%) patients. This condition affects athletes and soldiers undergoing military training and, in many cases, is an expression of an overuse syndrome. The incidence of these lesions was 3.5% in a series of relatively young patients. The lesion should be suspected in cases of unexplained knee pain in the athlete and soldier and in patients with previous negative arthroscopic examinations or meniscal lesions that were treated but remained unresolved. To our knowledge, bleeding from "closed" cartilage lesions has not been previously described. We raise the question of whether arthroscopic probing and cartilage puncturing is the method of treatment.