Saturday, October 1, 2011

Chondrolysis of the shoulder and 'pain pumps'

Chondrolysis of the shoulder is a complication of shoulder procedures in which the cartilage of the joint is permanently destroyed. Recently we published an article in the Journal of Bone and Joint Surgery on the risk factors for chondrolysis after shoulder arthroscopy. The abstract of this article is quoted here:

"Background: Glenohumeral chondrolysis is a complication of arthroscopic shoulder surgery characterized by the dis- solution of the articular cartilage of the glenoid and the humeral head. An analysis of 375 intra-articular shoulder arthroscopic surgical procedures by an individual community orthopaedic surgeon was performed to explore which factors or combinations of factors might be associated with glenohumeral chondrolysis.

Methods: The occurrence of chondrolysis was correlated with several demographic and surgical variables with use of hazard ratios from Cox proportional hazards models and Kaplan-Meier survivorship curves. Sensitivity analysis was used to examine the effect of two different definitions of the date of the onset of chondrolysis.

Results: In this cohort, each case of documented chondrolysis was associated with the intra-articular post-arthroscopic infusion of a local anesthetic, either Marcaine (bupivacaine) or lidocaine. In an analysis of the group that received an intra-articular postoperative infusion of a local anesthetic, the risk of chondrolysis was found to be greater for those with one or more suture anchors placed in the glenoid, for younger patients, and for those who had the surgery near the end of the ten-year study period.

Conclusions: To our knowledge, this is the first Level-II retrospective cohort study of the factors associated with the development of post-arthroscopic glenohumeral chondrolysis. In this cohort of intra-articular shoulder arthroscopic pro- cedures, chondrolysis was observed only in cases in which either Marcaine or lidocaine had been infused into the joint during the postoperative period. Avoiding such a postoperative infusion may reduce the risk of chondrolysis."


This month, our former shoulder fellow, Samer Hasan and colleagues published an article in the Journal of Bone and Joint Surgery, Glenohumeral Chondrolysis Associated with Use of an Intra-Articular Pain Pump Delivering Local Anesthetics Following Manipulation Under Anesthesia: A Report of Four Cases, that further confirms the causational relationship between intra-articular pain pumps and chondrolysis. The abstract of this article is quoted here:


"Glenohumeral chondrolysis is a devastating condition characterized by rapid dissolution of the articular cartilage surfaces of the glenoid and the humeral head. Patients typically present with a painful stiff joint, and radiographs demonstrate joint space narrowing and subchondral cystic changes. Because most cases of glenohumeral chondrolysis have occurred following arthroscopic shoulder surgery, the term “post-arthroscopic glenohumeral chondrolysis” (PAGCL) has been used to describe this condition. Several causative factors have been implicated, including suture anchors that are prominent or that become loose1, excessive intra-articular use of thermal heat, and intra-articular pain pump (IAPP) catheters delivering local anesthetics. Most of the patients described developed glenohumeral chondrolysis following arthroscopic stabilization procedures in which one or more suture anchors were employed, with or without adjunctive use of thermal heat, and in which an IAPP was placed at the conclusion of the procedure to deliver local anesthetics for postoperative analgesia.

To the best of our knowledge, glenohumeral chondrolysis developing after the use of an IAPP and without arthroscopy has not been described previously. We report four cases of glenohumeral chondrolysis that occurred following the use of an IAPP delivering either 0.25% or 0.5% bupivacaine with epinephrine for forty-eight to sixty hours after isolated manipulation of the shoulder under anesthesia, without a surgical procedure. In all four patients, the initial treatment, including manipulation and placement of an IAPP (AmbIT; Sorenson Medical Products, West Jordan, Utah), was done elsewhere by the same orthopaedic surgeon between March 2006 and August 2007. One of the four patients was treated with a subsequent prosthetic shoulder arthroplasty by another surgeon prior to referral to the senior author (S.S.H.). Each of the four patients in this series was informed that data concerning his or her case were submitted for publication, and verbal consent was obtained. A formal written consent specific to this case report was not obtained, owing to the retrospective nature of this work."

The significance of Dr Hasan's article is that (1) chondrolysis occurred without any intra-articular arthroscopic procedure (so the condition could not have resulted from thermal necrosis, suture anchors, or surgical mishaps) and (2) that some of the cases were associated with low concentrations of local anesthetics (0.25% bupivacaine).

Based on this information, one can conclude that the use of pain pumps for the intra-articular infusion of local anesthetics puts the patient at risk for the permanent loss of cartilage known as chondrolysis.

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