Clinical Outcomes of Ultrasound-Guided Transmeniscal Injection in Medial Compartment Knee Osteoarthritis

Abstract

The purpose of this study was to introduce the ultrasound-guided transmeniscal injection in medial compartment knee osteoarthritis and analyze the clinical outcomes. Materials and Methods: The electronic medical records of 36 patients with medial compartment knee osteoarthritis who were treated with an ultrasound-guided transmeniscal injection from March 2019 to July 2019 were accessed for this retrospective review. Using an ultrasound guided spinal needle, the patients received an intra-articular steroid injection at the medial compartment of the knee. A physical examination was conducted at the initial visit (pre-injection), and at one week, four weeks, and eight weeks after the injection. The numeric pain rating scale (NRS), Lequesne index, and Western Ontario and McMaster Universities Osteoarthritis (WOMAC) score were measured at each visit and analyzed over time. The percentage change of the patients who revealed substantial improvement was analyzed. The NRS, Lequesne index, and percentage of patients, who revealed substantial improvement over time classified by osteoarthritis grade, were analyzed. Results: The NRS and Lequesne index decreased at one week, four weeks, and eight weeks after the injection compared to the initial baseline, and the pain-relief effect continued without change until eight weeks. The percentage of patients who showed substantial improvement at one, four, and eight weeks was 50.0%, 47.2%, and 52.8%, respectively. The WOMAC scores decreased at one, four, and eight weeks compared to the initial baseline, and the decrease was continued without any difference until eight weeks. The percentage of patients with osteoarthritis stage 1 or 2 who revealed more than substantial improvement was significantly higher at one, four, and eight weeks than those with osteoarthritis stages 3 or 4 (p<0.05). Conclusion: In patients with medial compartment knee osteoarthritis, the pain reduction and functional improvement persisted for at least eight weeks after the ultrasound-guided transmeniscal injection at the medial compartment. In particular, patients with medial compartment osteoarthritis stage 1 or 2 showed more effective pain reduction.