Accuracy of Ultrasound Guided Versus Blind Knee Intra-articular Injection for Knee Osteoarthritis Prolotherapy

Knee osteoarthritis (OA) is one of the most common joint disabling diseases among adult patients. Symptomatic knee OA occurs in 10% men and 13% in women aged 60 years or older but is likely to increase due to the aging of the population and the obesity epidemic [1]. Osteoarthritis (OA) is characterized by progressive loss of articular cartilage, subchondral bone sclerosis, osteophyte formation, changes in the synovial membrane, and an increased volume of synovial fluid with reduced viscosity [2]. It is a complex disease with unknown etiology but evidence is growing for the role of systemic factors (such as genetics, dietary intake, estrogen use, and bone density) and of local biomechanical factors (such as muscle weakness, obesity, and joint laxity) [3]. Current mainstay of microinvasive therapy is prolotherapy by intra-articular injections. Prolotherapy with dextrose and with prolozone resulted in the same pain relief or functional improvement in patients with mild to moderate knee OA [4]. A randomized controlled trial (RCT) reported significant improvement in knee OA pain scores when treated with prolotherapy [5]. Prolotherapy results in progressive improvement of knee pain, function and stiffness in long-term follow-ups [6]. Blind intra-articular injection is still the choice of injections for many clinicians with acceptable success rate [7]. However, it could result in extra-articular approach in some patients. Besides, accidental collision of the needle tip with the superolateral pole of the patella during attempted aspiration or injection of the knee joint could led to pain, as well as damage to the chondral cartilage of the patella [8]. Although, ultrasound has been recommended for intra-articular injection, however its accuracy only been tested on cadaver.