Archive | February 2019

Persistent Pain after TKA: Can it Be Trained Away?

The anticipation of postoperative pain associated with a large operation such as a total knee arthroplasty (TKA) scares many patients. Some worry to the point of “catastrophizing” pain prior to surgery. As orthopaedic surgeons, we try to assuage our patients’ fears through preoperative education and multimodal pain-management modalities after surgery, but there are still some patients in whom the fear of pain—and the pain itself that inevitably accompanies arthroplasty— negatively affect their outcome. Preparing such patients for surgery and helping them recover afterward despite this high anxiety are big challenges for the orthopaedic care team. Some data suggest that cognitive behavioral therapy (CBT) might help.

However, a multisite randomized trial by Riddle et al. published in the February 6, 2019 issue of JBJS did not find any differences in pain or function among patients with moderate to high preoperative pain catastrophizing scores who underwent a form of CBT focused on pain coping skills, when their outcomes were compared to those of similar patients in “usual care” or “arthritis education” arms of the study. Each group had similar WOMAC pain scores and pain catastrophizing scores to start, and all patients were found to have significant but very similar decreases in their pain scores at 2, 6, and 12 months postoperatively. Independent assessors determined that the quality of the intervention in the coping-skills and arthritis-education arms was high, suggesting that it was not poor-quality interventions that accounted for the consistent similarities among the 3 groups.

While there are many physiological and psychological factors contributing to an individual’s experience of pain, the results of this study ran surprisingly counter to prior evidence. The authors speculate that differences between the 3 groups may have been masked by the fact that all patients had such a large decrease in pain after the TKA. While that would appear to be  good news, we know that there is a stubbornly large subset of patients (cited in this article as 20%) who undergo a technically and radiographically ”successful” knee arthroplasty only to have continued pain without an obvious cause. (See related OrthoBuzz Editor’s Choice post.)

These findings lead me to believe a statement that probably cannot be proven: there are some patients who will experience function-limiting pain no matter what surgery is performed, no matter which drugs are administered, and no matter what rehabilitative therapy is provided. Learning how to identify those patients and clearly communicating expectations to them pre- and postoperatively might help improve their satisfaction with their procedure.

Chad A. Krueger, MD
JBJS Deputy Editor for Social Media

Smoking, Depression Adversely Affect Outcomes after TAA

After some relatively poor results in the 1980s, there was a “reboot” with total ankle arthroplasty (TAA) in the late 1990s to improve outcomes so that TAA would provide a reliable treatment for patients with end-stage ankle arthritis. Advances in the understanding of the biomechanical requirements for ankle prostheses and which patients might benefit from them the most—plus the realization  that TAA is a technically demanding surgical procedure that requires advanced education—have vastly improved the outcomes of these procedures. In fact, TAA has become reliable enough that we can now begin to tease out the patient variables that seem to affect outcomes.

In the February 6, 2019 issue of The Journal, Cunningham et al. use an extensive clinical TAA registry to identify patient characteristics that impact TAA outcomes. The good news is that, 30-plus years after the inauspicious outcomes of first-generation TAA, overall pain and function significantly improved among the patients in this study. However, current smoking was associated with poorer patient outcomes at the 5-year follow-up, as it seems to be with the vast majority of orthopaedic procedures. Also, at a mean 1- to 2-year follow-up,  a previous surgical procedure on the ankle was associated with significantly smaller improvements in at least 1 patient-reported outcome. This makes sense because prior surgery leads to scarring and its attendant risk of infection and increased difficulty with exposure and the ideal placement of TAA components. Cunningham et al. also identified depression as being associated with worse TAA outcomes at all follow-up points, adding to our already ample body of evidence that patient psychological factors play a major role in orthopaedic surgical results.

Interestingly, these authors found that patients undergoing staged bilateral ankle arthroplasty did not do as well as those undergoing simultaneous bilateral TAAs. And somewhat surprisingly, the authors found obesity to be associated with better outcomes at the 5-year follow-up. This may be related to increased bone density and greater soft-tissue coverage, but this finding is still seemingly counterintuitive based on everything else we know about the negative associations between obesity and outcomes of other joint replacements.

As more surgeons and orthopaedic centers make use of TAA, it will be important for us to follow the lead of the total knee and total hip communities in providing large datasets to further clarify which factors—patient-related and surgical—lead to the best and worst patient outcomes. This study by Cunningham et al. provides a starting point upon which other research will hopefully build.

Marc Swiontkowski, MD
JBJS Editor-in-Chief