To the Editor:

We appreciate Dr. Muratli’s interest in our paper. We agree that the donor site in ACL reconstruction is a significant source of post-operative pain for both hamstrings and bone-tendon-bone autograft procedures. We also agree that this pain is completely extra-articular and any intra- articular analgesic – either narcotic or local anesthetic, should have little to no effect on this pain source.

Any extra-articular source of pain in our study was addressed with multi-modal pain therapy. This consisted of cold therapy through local application of ice post-operatively, pre-emptive analgesia with Ketorolac during the procedure, and systemic analgesia as needed. This was all standardized and all patients received the same multi-modal treatments with the exception of the amount of systemic analgesia, which was recorded and used as an outcome measurement.

Intra-articular morphine was shown to be effective in relieving overall pain in our study when compared to methadone or placebo. We assume that this intra-articular morphine was addressing only the pain from within the knee joint and had no effect on the extra-articular donor site. Regardless, the patients had less overall pain with intra-articular morphine while methadone was no better than placebo.

There are several reasons why we chose ACL reconstruction as our model for introducing intra-articular methadone as a possible long-acting analgesic. This is a commonly performed procedure and the post-operative pain can be significant and long lasting. This pain can interfere with post-operative rehabilitation and compromise surgical outcome. There is a real need for improved pain control in ACL reconstruction. In our experience, these issues are not nearly as problematic with all intra- articular arthroscopic procedures such as meniscal, or chondral procedures.

To the Editor:

We wish to congratulate Stewart and colleagues for showing that intra-articular methadone in certain doses can be used safely in the knee.

The authors stated that it is known that intra-articular narcotics have proven efficacy for providing pain relief following knee arthroscopy but this effect is short-lived. They hypothesized that methadone, with its long serum half-life could provide improved and prolonged pain relief in arthroscopic anterior cruciate ligament reconstructions but considering their findings they found that methadone does not provide improved postoperative analgesia.

Our main concern with this study is that although the authors excluded the use of tournequets to prevent other pain sources in their patient group, we believe that with arthroscopic anterior cruciate ligament reconstructions, the donor site itself is an important source of extraarticular pain. In particular, bone patellar tendon bone autograft harvesting causes pain and this site is completely extraarticular. We wonder if there is any logical explanation of the pain relief mechanism concerning an extra-articular donor site when intraarticular injection techniques are used. One possibility is an analgesic effect through the systemic absorbtion and morphines’ analgesic and anti-inflammatory properties in synovium (1) but this can be effective only in the intrasynovial part of the procedure.

We believe that intraarticular methadone injection should be tried in substantial studies where the procedure is all intraarticular, such as arthroscopic meniscal or chondral surgeries. It may have been better to tried it in these kinds of procedures first.

References: 1.Marchal JM, Delgado-Martinez AD, Poncela M, Valenzuela J, de Dios Luna J. Does the type of arthroscopic surgery modify the analgesic effect of intraarticular morphine and bupivacaine? A preliminary study. Clin J Pain. 2003 Jul-Aug;19(4):240-6.