‘An Alien Knee’: Discomfort with Total Knee Replacement

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A study interviewing patients who received total knee replacement for osteoarthritis find that, despite the welcome pain relief, some also experience less pleasant psychological impacts.

For their study published in Arthritis Care & Research, UK researchers sought to bridge a knowledge gap of where people were dissatisfied with their total knee replacements even though they reported less pain and better function.

Using semi-structured interviews, researchers elicited comments from 34 patients, meant to explore patients’ thoughts about their knee implants. They received a lot of feedback about non-pain discomfort and feelings of dissonance.

“My leg feels like it’s made of lead,” one patient told researchers.

“It feels like someone is holding your knees, when you move, it’s like someone is … putting pressure there,” said another.

A third said: “I know it’s not my knee. It’s an alien knee in there. I don’t really feel connected to it.”

“Typically, the assessment of patient-reported outcomes after joint replacement focuses on functional outcome and pain relief as the main determinant of satisfaction,” the researchers explained. “This narrow perspective is compounded by poor definitions of satisfaction after surgery, and there is little research on how and why some patients express dissatisfaction with joint replacement and what they are dissatisfied about.”

Citing a study of hand surgery patients in which patients “spoke about their hand as if it were an object separate from their self,” the researchers argued that a psychological concept called embodiment could help explain the patients’ feelings of dissonance.

They wrote: “Embodiment refers to the experience of the body as both subject and object, such that this idea impacts the way in which a person sees and interacts with the world, and vice versa. Embodiment provides a way of understanding how one experiences limits of possible action, a sense of control, and empowerment over physical action.”

Initially, the researchers weren’t planning to focus on embodiment, but, they explained, “by the third interview we noted that some participants described sensations of discomfort such as heaviness or numbness when discussing pain and some described their knee as ‘alien,’ ‘foreign,’ or ‘not part of’ themselves. In response to these findings, the interviewer sought to elicit views about any such sensations in subsequent interviews, if this topic was not broached first by the participant.”

Their study emerged from an earlier one focusing on reasons for avoiding healthcare encounters post-surgery and involved the same participants, who had lingering pain and discomfort. The semi-structured interview covered pain as well as how patients managed it. After a third interview, patients who reported feelings of alienation from their implant were asked about it in more detail.

Participants reflected the general knee-replacement population – most in their 60 and 70s, and just over half were women. Of the 34 patients, 24 were between 2 and 4 years out from their surgery.

Physical types of non-pain discomfort were commonly reported, such as feelings of numbness and/or heaviness, as well as sensations of pressure applied externally. One man said it felt like the skin over his knee was stretched tight. Separate from these sensations were reports that the limb no longer felt like a part of them but something foreign, like an external prosthesis. Some patients complained of a lack of control. “That knee just wouldn’t do what it’s told to do,” one told the interviewer.

Others said they hadn’t regained trust in the knee, with one man still using a cane for fear of falling.

Overall, the researchers found that the patients’ experience were quite similar to those of amputees getting used to their prosthetic limbs. This could be partly explained by often experiencing years of pain and loss of function before the joint replacement.

“Presurgical chronic pain, instability, and untrustworthiness might continue to influence [mental] incorporation of the prosthesis afterwards,” the researchers suggested.

And there is a potential clinical implication for the findings: “Our study suggests that the interest for rehabilitation becomes not only strengthening the joint and promoting full recovery to tasks, but also modifying a person’s relationship with the new joint to achieve full incorporation or re-embodiment.”

The researchers proposed that other programmes developed for other conditions could be helpful, such as external prosthesis use as well as complex regional pain syndromes.

“Our focus should not be on the absence or loss of embodiment,” the researchers added, “but on employing a multidisciplinary approach to using the concept to guide the development of pre-rehabilitative strategies and appropriate outcome measures.”

Source: MedPage Today