Preoperative Osteopathic Manipulative Therapy Improves Postoperative Pain and Reduces Opioid Consumption After Total Knee Arthroplasty

Participants

• Number: 70 people (47 female and 23 male)
• Criteria of inclusion: Unilateral total knee arthroplasty for osteoarthritis in a knee that had not undergone any previous surgeries.
• Criteria of exclusion: a history of surgery to the knee to be operated with arthroplasty; need for bilateral arthroplasty; refusal to receive OMTh.
• Groups of study: 2 non-randomized groups
  • Group 1: preoperative management with OMTh, 35 people (23 female and 12 male, mean age 73.9 years)
  • originally 41 people, but 2 were lost to follow-up and 3 were excluded from the analysis
  • Group 2: traditional preoperative management, 35 people (24 female and 11 male, mean age 74.6 years)
    • originally 40 people, but 5 were excluded from the analysis
    • At the beginning of the study the IKS scores related to knee pain and function were worse in group 1 than in group 2

Interventions and evaluations

• Knee pain at rest and while walking assessed with VAS 1 month after surgery
• Average weekly knee pain assessed with VAS during the first month after surgery
• Evaluation of the presence of night pain and of the consumption of sleeping pills, opioids or morphine at least once a week during the first month
• IKS score and WOMAC index assessed 6 and 10 months after surgery
• 2 OMT sessions (3 weeks and 1 week before the arthroplastic)
• OMTh:
  • at the first visit, mobilization of all the body joints using long-level manipulation
  • at the second visit, myofascial relaxation following this order: ankle, leg and interosseous membrane, knee, hip and pelvis
• OMTh performed by non-US-trained osteopaths

Results

• Primary outcomes: 1 month after the arthroplasty, the group with OMTh reported a knee pain at rest 3 times lower than the group with traditional preoperative management (6.8 vs 20.9) in a statistically significant manner.
• Secondary outcomes: 1 month after the arthroplasty, the group with OMTh reported knee pain while walking about 3 times lower than the group with traditional preoperative management (7.9 vs 23.5) in a statistically significant manner. Likewise, the average weekly knee pain experienced during the first month was lower in the group with OMTh always in a statistically significant manner.

During the first week after surgery, statistically significantly fewer people in the OMTh group reported a consumption of morphine derivatives and analgesics than in the group without OMTh. In the remaining weeks, there were no differences, nor was there any difference in the number of people who used sleeping pills or who experienced pain at night at least once a week. With regard to IKS and WOMAC scores, statistically significant differences did not emerge either after 6 months or after 12 months from surgery, although a score series was in favor of OMTh (eg, the WOMAC score regarding the difficulty in performing daily tasks was worse in the group without OMTh).

• Further analyses: in the group with OMTh, knee pain at rest, but not while walking, was statistically significantly lower the day before surgery than before starting preoperative management with OMTh.

Discussion

OMTh proved to reduce postoperative knee pain both at rest and while walking, thus also favoring a lower consumption of analgesics, although it does not seem to have affected the functional capacity at 6 and 12 months after surgery.

Nevertheless, the decrease in opioid consumption is an important result given the opioid “epidemic” emerged in recent years. OMTh may have sorted these effects thanks to a direct action on blood flow and on the lymphatic drainage of the knee inflammation. Future studies could be done trying to compare OMTh to a sham treatment.