Subacute Pain After Total Knee Arthroplasty

ABSTRACT

Acute pain during and immediately after total knee arthroplasty (TKA) can be well controlled by spinal anesthesia, local infiltration analgesia, and peripheral nerve blocks; this enables early or fast-track rehabilitation. However, about half of patients have clinically significant pain in the following weeks. Active movements and rehabilitation of joint function, muscle strength, and ability to maintain balance and prevent falls all become more difficult when the joint is painful on movement. Intensive analgesic and antihyperalgesic treatment during the first few weeks after TKA surgery may reduce the risk of chronic pain after this operation, which is itself intended to remove the patient's chronic osteoarthritis pain. Spinal cord stimulation may be an effective option for patients with mainly neuropathic pain after TKA surgery.

This report is adapted from paineurope 2013; Issue 4, ©Haymarket Medical Publications Ltd., and is presented with permission. paineurope is provided as a service to pain management by Mundipharma International, Ltd., and is distributed free of charge to health care professionals in Europe. Archival issues can be accessed via the Web site: http://www.paineurope.com, at which European health professionals can register online to receive copies of the quarterly publication.

KEYWORDS :

• arthroplasty
• infiltration analgesia
• knee
• nerve blocks
• pain
• postoperative
• spinal anesthesia

COMMENTARY FROM SWITZERLAND

Alain Borgeat

This case illustrates one of the major problems occurring after surgery, the issue of postoperative chronic pain syndrome. Neuropathic pain in the area of the common peroneal nerve can be caused by surgery, tourniquet, some regional blocks, or a combination of all these factors.

Electroneuromyography may have been helpful in this case, not only to localize the site of damage, but also to provide some clues about recovery. The treatment of this patient is standard and reflects what would have been done in my institution. Light physiotherapy to avoid muscle atrophy may also have been useful.

Severe preoperative pain—as in this case—is one of the most recognized risk factors for the occurrence of postsurgical pain syndrome after total joint arthroplasty.¹ Other factors include preoperative depression and anxiety. A perioperative multimodal analgesic treatment regimen including regional catheters, nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol, and α₂-agonists, with ketamine if needed, may have been warranted. It is well known that opioids have limited value in this context.²

Severe nerve damage (neurapraxia or neurotmesis) requires a long recovery. There is no treatment to speed up recovery, although functional electrical stimulation has shown promising results in animals.

COMMENTARY FROM SWEDEN

Narinder Rawal

Intraoperative nerve damage to peroneal and tibial nerves can occur during TKA but most cases can expect to recover completely.^1,2 Most nerve injuries do not cause neuropathic pain; in one study it was shown that although 90% of nerves were injured, only 5% caused neuropathic pain.² A recent review showed that the neuropathic component in persistent postsurgical pain (PPSP) varies with the type of surgery, after TKA it was only about 6%.¹ Although the neuropathic component in this patient's pain appears high, other risk factors for PPSP such as psychosocial, environmental and patient-related genetic factors also need to be considered.

Studies have shown improved pain, function, and quality of life after TKA; however, up to 20% of patients are dissatisfied, mainly due to PPSP.³ A survey of more than 1000 patients reported a 53% incidence of PPSP after TKA with average pain scores of 3–5/10, these patients had significantly lower health-related quality of life scores.³

The underlying etiology of PPSP is still unclear.^1,2 Injury to peripheral nerves during surgery or ongoing inflammation have been stipulated as primary causal factors. Mechanisms for increased acute pain leading to PPSP are speculative but may involve either peripheral or central sensitization. The intensity of perioperative pain has been identified as a key risk factor in some studies; however, no single factor seems to play a significant role. The American Society of Anesthesiologists practice guidelines for multimodal management of postoperative pain can be recommended, these include wound infiltration with a long-acting local anesthetic, paracetamol, NSAIDs, and calcium-channel blockers.⁴

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Notes

Alain Borgeat, MD, is Professor and Head of the Department of Anesthesiology, Balgrist University Hospital, Zurich, Switzerland.

Narinder Rawal, MBBS, MD, PhD, is a Professor at Department of Anesthesiology and Intensive Care at University Hospital in Örebro, Sweden.