The efficacy of arthroscopy following total knee replacement.

We evaluated the utility and safety of arthroscopy for diagnosing and treating symptoms in problematic total knee replacements. From 1988 to 1995, 40 arthroscopies were performed on 38 patients with an average age of 68.4 years. The average onset of symptoms post knee replacement was 33.7 months (range 1 month to 15 years), and the average duration of symptoms prior to arthroscopy was 15.6 months (range 1 month to 5 years). Presenting symptoms included pain in 73%, catching or soft tissue impingement in 35%, and stiffness in 20% of patients. Our protocol involves 24 hours of perioperative, intravenous antibiotics, and two or three routine arthroscopic portals. There were no arthroscopy-related complications or infections. Arthroscopy successfully diagnosed the etiology of the patient's symptoms in all but one case (97.5%). Operative diagnoses included impinging soft tissue under the patella consistent with the "clunk" syndrome (43%), impinging hypertrophic synovitis elsewhere in the knee (15%), impinging PCL stump (10%), prosthesis loosening or wear (10%), and arthrofibrosis (20%). Arthroscopic treatment consisted of removal of impinging tissue or loose body as indicated. Additionally, eight of the patients had a manipulation under anesthesia with an average improvement in flexion of 26.3 degrees postoperatively. At an average follow-up of 19.9 months, 27.5% of knees had developed recurrent symptoms. Two of these patients had repeat arthroscopy for recurrent impinging hypertrophic synovitis. The rates of successfully relieving symptoms without recurrence according to operative diagnosis were 82% for "clunks," 60% for other impinging synovium or soft tissue, and 63% for arthrofibrosis. Three patients underwent total knee revisions. Knees were rated at follow-up using the Knee Society rating system with patients divided according to functional category. The average Knee Society knee scores and function scores respectively were 93 and 92 for group A patients, 91 and 88 for group B patients, and 81 and 76 for group C patients. Arthroscopy successfully identified all cases of soft tissue impingement and prosthetic loosening or wear, and successfully treated 73% of patients without recurrence. There were no arthroscopy associated complications or infections. Thus, arthroscopy is a safe, effective tool for managing certain problematic knee replacements, especially "clunks," and may help to avoid revision or arthrotomy in some cases.