Minimizing Opioids After Joint Operation: Protocol to Decrease Postoperative Opioid Use After Primary Total Knee Arthroplasty

Furthermore, those with high preoperative use may experience worse outcomes relative to the opioid naive population as measured by arthritis-specific pain indices.¹³ In a well-powered retrospective study of patients who underwent elective orthopedic procedures, preoperative opioid abuse or dependence (determined by the International Classification of Diseases, Ninth Revision diagnosis) increased inpatient mortality, aggregate morbidity, surgical site infection, myocardial infarction, and LOS.¹⁴ Preoperative opioid use also has been associated with increased risk of ED visits, readmission, infection, stiffness, and aseptic revision.¹⁵ In patients with TKA in the VA specifically, preoperative opioid use (> 3 months in the prior year) was associated with increased revision rates that were even higher than those for patients with diabetes mellitus.¹⁶

Patient Education

Based on this evidence, we instruct patients to reduce their preoperative opioid dosing to zero (for patients with joint pain) or < 30 MED (for patients using opioids for other reasons). Although preoperative reduction of opioid use has been shown to improve outcomes after TKA, pain subspecialty recommendations for patients with chronic opioid use recommend considering adjunctive therapies, including transcutaneous electrical nerve stimulation, cognitive behavioral therapy, gabapentin, or ketamine.^17,18 Through patient education our team has been successful in decreasing preoperative opioid use without adding other drugs or modalities.

Patient Optimization

Preoperative patient optimization included 4 to 8 weeks of daily sets of physical activity instructions (prehab) to improve the musculoskeletal function. These instructions are given to patients 4 to 8 weeks before surgery and aim to improve the patient’s balance, mobility, and functional ability (Appendix). Meta-analysis has shown that patients who undergo preoperative PT have a small but statistically significant decrease in postoperative pain at 4 weeks, though this does not persist beyond that period.¹⁹

We did note a lower BMI in patients in the MOJO group. Though this has the potential to be a confounder, a study of BMI in > 4,000 patients who underwent joint replacement surgery has shown that BMI is not associated with differences in postoperative pain.²⁰

Surgeon and Surgical-Related Variables

Patients in the MOJO group had increased use of adductor canal blocks. A 2017 meta-analysis of 12,530 patients comparing analgesic modalities found that peripheral nerve blocks targeting multiple nerves (eg, femoral/sciatic) decreased pain at rest, decreased opioid consumption, and improved range of motion postoperatively.²¹ Also, these were found to be superior to single nerve blocks, periarticular infiltration, and epidural blocks.²¹ However, major nerve and epidural blocks affecting the lower extremity may increase the risk of falls and prolong LOS.^22,23 The preferred peripheral block at VAPHCS is a single shot ultrasound-guided adductor canal block before the induction of general or spinal anesthesia. A randomized controlled trial has demonstrated superiority of this block to the femoral nerve block with regard to postoperative quadriceps strength, conferring the theoretical advantage of decreased fall risk and ability to participate in immediate PT.²⁴ Although we are unable to confirm an association between anesthetic modalities and opioid burden, our clinical impression is that blocks were effective at reducing immediate postoperative pain. However, among MOJO patients there were no differences in patients with and without blocks for either pain (4.2 vs 3.8, P = .69) or opioid consumption (28.8 vs 33.0, P = .72) after surgery, though our study was not powered to detect a difference in this restricted subgroup.

Patients who frequently had reported postoperative thigh pain prompted us to make changes in our surgical technique, performing TKA without use of a tourniquet. Tourniquet use has been associated with an increased risk of thigh pain after TKA by multiple authors.^25,26 Postoperative thigh pain also is pressure dependent.²⁷ In addition, its use may be associated with a slightly increased risk of thromboembolic events and delayed functional recovery.^28,29

Because postoperative hemarthrosis is associated with more pain and reduced joint recovery function, we used topical TXA to reduce postoperative surgical site and joint hematoma. TXA (either oral, IV, or topical) during TKA is used to control postoperative bleeding primarily and decrease the need for transfusion without concomitant increase in thromboembolic events.^30,31 Topical TXA may be more effective than IV, particularly in the immediate postoperative period.³² Although pain typically is not an endpoint in studies of TXA, a prospective study of 48 patients showed evidence that its use may be associated with decreased postoperative pain in the first 24 hours after surgery (though not after).³³ Finally, the use of intra-articular injection has evolved in our clinical practice, but literature is lacking with regard to its efficacy; more studies are needed to determine its effect relative to no injection. We have not seen any benefits to using cryotherapy in our practice; considering the costs for equipment and health care provider time, cryotherapy was not included in our new protocol.

Limitations

This is a nonrandomized retrospective single-institution study. Our study population is composed of mostly males with military experience and is not necessarily a representative sample of the general population eligible for joint arthroplasty. Our primary endpoint (reduction of opioid use postoperatively) also was a cornerstone of our intervention. To account for this, we set a very large effect size in our power analysis and evaluated multiple secondary endpoints to determine whether postoperative pain remained well controlled and complications/readmission minimized with our interventions. Because our intervention was multimodal, our study cannot make conclusions about the effect of a particular component of our treatment strategy. We did not measure or compare functional outcomes between both groups, which offers an opportunity for further research.