Local Anesthetic Use in Musculoskeletal Injections.

CASE PRESENTATION An obese and otherwise healthy 62-year-old male presents to the clinic with chronic but worsening right medial knee pain. Pain is worse with weight-bearing, especially when descending hills and stairs, and disrupts his sleep. Physical examination reveals a trace effusion, tenderness to palpation over the medial joint line, and mild crepitus appreciated with range of motion. Rosenberg/lateral/sunrise radiographs reveal medial joint space narrowing and small medial and patellofemoral compartment osteophytes, consistent with osteoarthritis. He is counseled on weight loss, prescribed a course of physical therapy, and encouraged to use nonsteroidal anti-inflammatory drugs as needed. He is also offered a joint injection for more immediate relief. He asks if the numbing medications used in joint injections are safe.