The posteromedial portal in knee arthroscopy: an analysis of diagnostic and surgical utility.

We reviewed 400 consecutive knee arthroscopy cases in a predominantly sports medicine practice to determine (1) the frequency of posteromedial portal usage under a prospectively established set of indications, and (2) the impact of posteromedial portal access on patient diagnosis and management. Diagnostic posteromedial portals were used in 22% of anterior cruciate ligament (ACL)-deficient knees, and in 11% of stable knees with nonpatellar (usually meniscal) lesions. When used, posteromedial portal visualization showed treatable lesions 64% of the time, the majority of which were repairable peripheral meniscus tears. In 63% of these cases, no definite lesion had been identified by initial routine anterior portal viewing and probing. Of the 22 patients with posteromedial meniscus tears that were discovered only via posteromedial portal access, 9 had recently undergone anterior portal arthroscopy by other surgeons, during which none of these tears were detected. Posteromedial surgical portals (19 cases) were most useful for synovectomy, posterior cruciate stump resection before arthroscopic reconstruction, and posterior horn medial meniscectomy in exceptionally tight knees. Posteromedial portal access is often useful diagnostically in cases where (1) posteromedial meniscal lesions are frequent (i.e., ACL-deficient knees) and/or suspected on the basis of preoperative symptoms or imaging studies, and (2) full, direct visualization of the entire superior meniscosynovial junction is not possible via standard anterior portals. The option of a surgical posteromedial portal should be entertained whenever frontal approaches for posteromedial instrument work prove inefficient or unsuccessful.