Given the growing prevalence of obesity around
the world and its association with osteoarthritis of the knee, orthopaedic
surgeons need to be familiar with the management of the obese patient
with degenerative knee pain. The precise mechanism by which obesity
leads to osteoarthritis remains unknown, but is likely to be due
to a combination of mechanical, humoral and genetic factors. Weight loss has clear medical benefits for the obese patient
and seems to be a logical way of relieving joint pain associated
with degenerative arthritis. There are a variety of ways in which
this may be done including diet and exercise, and treatment with
drugs and bariatric surgery. Whether substantial weight loss can
delay or even reverse the symptoms associated with osteoarthritis
remains to be seen. Surgery for osteoarthritis in the obese patient can be technically
more challenging and carries a risk of additional complications.
Substantial weight loss before undertaking total knee replacement
is advisable. More prospective studies that evaluate the effect
of significant weight loss on the evolution of symptomatic osteoarthritis
of the knee are needed so that orthopaedic surgeons can treat this
patient group appropriately.
The patient with a painful arthritic knee awaiting
total knee arthroplasty (TKA) requires a multidisciplinary approach.
Optimal control of acute post-operative pain and the prevention
of chronic persistent pain remains a challenge. The aim of this
paper is to evaluate whether stratification of patients can help
identify those who are at particular risk for severe acute or chronic
pain. Intense acute post-operative pain, which is itself a risk factor
for chronic pain, is more common in younger, obese female patients
and those suffering from central pain sensitisation. Pre-operative
pain, in the knee or elsewhere in the body, predisposes to central
sensitisation. Pain due to osteoarthritis of the knee may also trigger
neuropathic pain and may be associated with chronic medication like
opioids, leading to a state of nociceptive sensitisation called
‘opioid-induced hyperalgesia’. Finally, genetic and personality
related risk factors may also put patients at a higher risk for
the development of chronic pain. Those identified as at risk for chronic pain would benefit from
specific peri-operative management including reduction in opioid
intake pre-operatively, the peri-operative use of antihyperalgesic
drugs such as ketamine and gabapentinoids, and a close post-operative
follow-up in a dedicated chronic pain clinic. Cite this article:
Primary total knee arthroplasty (TKA) is a reliable
procedure with reproducible long-term results. Nevertheless, there
are conditions related to the type of patient or local conditions
of the knee that can make it a difficult procedure. The most common
scenarios that make it difficult are discussed in this review. These
include patients with many previous operations and incisions, and
those with severe coronal deformities, genu recurvatum, a stiff knee,
extra-articular deformities and those who have previously undergone
osteotomy around the knee and those with chronic dislocation of
the patella. Each condition is analysed according to the characteristics of
the patient, the pre-operative planning and the reported outcomes. When approaching the difficult primary TKA surgeons should use
a systematic approach, which begins with the review of the existing
literature for each specific clinical situation. Cite this article:
