Editorial Commentary : Periarticular and Intra‐Articular Injections May Do the Right Thing for Patients’ Pain but May Be the Wrong Thing for Their Articular Cartilage: Be Careful

Periarticular and intra-articular injections are regularly used by orthopaedic surgeons both in the clinic and operative setting. These injections include the use of local anesthetics, nonsteroidal anti-inflammatories, steroidal anti-inflammatories, and other classes of pharmaceuticals. Local anesthetics can be injected alone or in conjunction with other pharmaceuticals to maximize pain control and to minimize narcotic use as part of a multimodal pain control algorithm. Use of intra-articular local anesthetics has been shown to improve postoperative pain scores and reduce intravenous and oral narcotic consumption and narcotic-related side effects, such as constipation, sedation, depression, respiratory depression, and long-term abuse potential. However, there have been reports of chondrolysis and other side effects from these injections. In general, it can be said that lidocaine is more chondrotoxic than bupivacaine and that methylprednisolone is more chondrotoxic when combined with either lidocaine or bupivacaine. Ropivacaine with steroid maybe less chondrotoxic, but this has yet to be established. It has been shown that ropivacaine with steroids may be toxic to chondrocytes as well as bovine tenocytes. In addition, it can be generalized that longer exposures, such as an indwelling, intra-articular catheter, are more chondrotoxic than shorter exposures, such as an intra-articular injection. Greater concentrations of lidocaine and bupivacaine (i.e., 1% vs 2% and 0.25% vs 0.5%, respectively) are more toxic to chondrocytes. Cellular morphine studies have resulted in conflicting reports of whether or not it is chondrotoxic. Both ketorolac and acetaminophen have been shown to decrease postoperative pain, but ketorolac also has been shown to be chondrotoxic in a human chondrocyte model. Doing the right thing for our patients' pain may be the wrong thing for their articular cartilage. Expansion of indications for these injections should be approached with caution.