A rare case of Haemophilus parainfluenzae septic knee following prolotherapy injections

Prolotherapy injections are becoming increasingly popular as a non-surgical treatment option for many chronic musculoskeletal conditions. Proposed benefits include reduced pain, reduced joint laxity and increased tendon strength. While a number of studies report that prolotherapy reduces pain and increases function for many conditions, the academic evidence remains extremely weak. Here, we discuss a case of a complex intra-articular knee infection in a young, previously healthy, female following prolotherapy injections for management of a partial-thickness anterior cruciate ligament (ACL) tear. To the best of our knowledge, this is the first report of its kind describing a potential complication of intra-articular prolotherapy injections.