Ultrasound-guided intra-articular knee injection in an obese patient.

A 35-yr-old woman was referred to our outpatient clinic for a right intra-articular knee aspiration and injection. She had a medical history notable for lymphedema and morbid obesity (Fig. 1). Her body mass index was recently calculated at greater than 60 kg/m(2). She had a history of four previous nonguided knee joint injections performed elsewhere that provided no significant improvement in pain. On physical examination, it was difficult to localize common knee joint bony landmarks, including the medial and lateral borders of the patella (Fig. 2). Consequently we opted to utilize ultrasound guidance for the knee joint injection via the technique described herein.