Background/Purpose: Knee needle arthroscopy (KNA) is a minimally invasive procedure consisting in insertion of a thin fiber-optic needle system in the joint cavity, followed by inspection, tissue sampling, therapeutic lavage, and if needed, steroids injection after the procedure. It is usually performed in an office-based setting, requiring only local anaesthesia, as an out-patient procedure. KNA is of particular interest as it can be used for diagnosis (in case of undifferenciated arthritis), scientific purposes (synovial biopsies serving for histology, proteomics, and genomics), and can serve as a therapeutic tool (mainly articular lavage). Few data have been published regarding safety of KNA, and available studies deal with a relatively small number of patients. Objective: To determine the incidence of overall and serious, notably septic, complications, and identify patients at higher risk.

Methods: We retrospectively reviewed the records of all arthroscopies performed in the rheumatology department of our teaching hospital between July 2002 and December 2015. Patients, suffering from a rheumatic disease, and knee complains underwent a KNA, either for the diagnosis, or for clinical research reason. The procedure was performed in a dedicated room under sterile conditions (extensive local disinfection and draping of the leg) and local anaesthesia, by a senior rheumatologist. Of note, joint needle aspiration was performed before the incision. The fluid (if obtained) was then sent for routine laboratory analysis: cellularity, crystal detection and culture. The patient was allowed to walk immediately after the procedure. All patients signed an informed consent before the procedure.

Results: A total of 919 patients were included in the study. Two-thirds (65.4%) were female and mean age was 52 years. A total of 1,136 KNA were performed. Almost half of the patients suffered from rheumatoid arthritis (47%), 20.2% from osteoarthritis, 10.7% from spondylarthritis, 10.7% from undifferentiated arthritis, 4.9% from microcrystalline arthritis, 3% from connective tissue diseases, and 1.8% from idiopathic juvenile arthritis A few patients suffered from sarcoidosis, hemochromatosis, villonodular synovitis and polymyalgia rheumatica. Of note, a diagnosis of septic arthritis was suspected in 7 patients by joint inspection and confirmed by positive cultures. The overall rate of complications was 1.5% and the rate of infection was 0.79%. Minor complications included 2 cases of subcutaneous hematoma, 4 cases of delayed healing with persistent superficial wound, 1 case of local skin atrophy after glucocorticoids (GC) injection and 1 case of pancreatitis, also attributed to the injection of GC in a HIV positive patient, treated with antiretrovirals. We observed no cases of post-intervention hemarthrosis, bleeding or thrombo-embolic complications. All serious complications were infectious. We identified 7 cases of confirmed septic arthritis, 1 case of septic bursitis and 1 case of possible septic arthritis (no bacteriological proof). Patients were predominantly male (6/9), most of them with ≥2 comorbidities. 4 out of 9 patients were treated by oral GC and all patients received intraarticular glucocorticoids during the procedure. As expected, Staphylococcus aureuswas the most frequent pathogen identified. On the 9 infected patients, 7 were hospitalized, treated with IV antibiotics and underwent a surgical arthroscopic lavage 24-48 hours following the admission. Clinical evolution showed improvement in all cases with no long-term morbidity.

Conclusion:

KNA is a safe, and well-tolerated procedure, with less than 1% of septic complications. It’s slightly lower than conventional arthroscopy, with the additional advantages of local anaesthesia, fast recovery and lower cost. Special caution should be applied to patients with comorbidities, previous infection, or treated with GC.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/safety-of-the-knee-needle-arthroscopy-a-review-of-1136-procedures-in-919-patients/