Disparity Between Perceived and Actual Opioid Prescriptions by Orthopaedic Surgeons After Total Joint Arthroplasty

Abstract

Introduction:

Healthcare institutions have sought to standardize opioid prescribing after elective total joint arthroplasty. The purpose of this study was (1) to compare opioid prescriptions at discharge with perceived opioid prescribing patterns and (2) to determine the relationship between preoperative adjunctive treatments and opioids prescribed at discharge.

Methods:

All surgeons who performed total joint arthroplasty of the shoulder, hip, or knee from January 1, 2021, to October 4, 2023, at a single academic institution were included. Surgeons completed a survey assessing perceived opioid prescriptions at discharge and perioperative pain protocols. Actual prescriptions were captured using our institutional opioid database. All opioid prescriptions were converted to morphine milligram equivalents (MMEs).

Results:

Orthopaedic surgeons prescribed on average 594.2 MMEs more than they perceived as their postoperative protocol. They prescribed an additional 60.9 MMEs for every 10 MMEs that they perceived they were prescribing. Patients receiving liposomal bupivacaine were prescribed on average 597 fewer MMEs and had fewer opioid prescriptions (P < 0.001). Genicular nerve blocks and cryoneurolysis were associated with fewer prescribed MMEs (P < 0.001).

Conclusion:

Orthopaedic surgeons prescribe substantially more opioids than intended. This study underscores the need for standardized opioid prescribing practices and the potential of adjunctive treatments in reducing opioid prescribing.

Postoperative pain control after orthopaedic surgery remains challenging for both patients and surgeons. Excess prescribing of opioids and their associated consequences are well documented in literature.^1,2 Attention has been directed at mitigating opioid use, specifically in the postoperative setting. However, postoperative opioid protocols may vary substantially among individual surgeons and institutions.

International institutions, including the Centers for Disease Control and Prevention (CDC), offer general guidelines for prescribing opioids but do not give specific dosing recommendations regarding the management of acute pain after total joint arthroplasty.^3,4 In an effort to standardize opioid prescribing, many institutions have implemented guidelines, often expressed in morphine milligram equivalents (MMEs).⁵ Our institution adopted their own guidelines for opioid prescribing after major orthopaedic surgeries (ie, total joint arthroplasty of the shoulder, hip, and knee), which limits the maximum quantity and strength of opioids to 30 tablets of oxycodone 5 mg or hydromorphone 2 mg. This equates to approximately 30 to 45 MMEs per day depending on the dosing interval. Table 1 provides a list of opioid medications prescribed postoperatively and their respective conversion to MMEs by the participating surgeons.³ Despite these guidelines, orthopaedic surgeons may vary in their preferred opioid prescription and adjuncts in hopes of adequately controlling postoperative pain. In fact, previous studies demonstrate that these guidelines may not accurately represent opioid prescription or consumption patterns among orthopaedic surgeons and their patients, respectively.^6,7

Table 1.

Various Narcotics Prescribed by Surgeons Involved in the Study and Conversion From Single Use to Morphine Milligram Equivalents

Opiate Prescribed	MME Conversion Factor	MME Per Tablet
Percocet 5 mg/325 mg	1.5	7.5
Norco 5 mg/325 mg	1	5
Tramadol 50 mg	0.1	5
Oxycodone 5 mg	1.5	7.5

MME, morphine milligram equivalent

Dowel et al.³

It is unknown whether the surgeon's perceived postoperative pain control regimen differs from what is actually prescribed. Discrepancies between perceived and actual opioid prescribing patterns may serve as a barrier to successfully addressing the opioid crisis from an orthopaedic perspective. The purpose of this study was to determine (1) whether the actual amount of postsurgical opioids prescribed by physicians after elective total joint arthroplasty was equal to what the physicians perceived they prescribed at time of discharge and (2) whether preoperative adjunctive treatments were associated with fewer opioids prescribed at discharge. It was hypothesized that orthopaedic surgeons prescribe more opioids than they perceived to have written and that patients receive fewer opioids at discharge when provided preoperative adjunctive treatments.

Methods

After obtaining institutional review board approval, a descriptive cross-sectional study was conducted on all orthopaedic surgeons within a single academic institution who performed total joint arthroplasty of the shoulder, hip, or knee from January 1, 2021, to October 4, 2023. A survey assessing each surgeon's postoperative pain management protocol including perceived opioid prescriptions at discharge and preoperative pain adjuncts was sent electronically to all participating surgeons. Each surgeon's perceived pain regimen was converted to total MMEs, defined as the number of units/day supply × MME conversion factor. The MME conversion factor was derived from the Centers for Disease Control and Prevention guidelines for prescribing opioids for pain.³ It represents an equianalgesic ratio that allows for a baseline conversion between opioid prescriptions. Each MME conversion factor is specific to the prescribed opioid such that the MME conversion factor for oxycodone and hydromorphone is 1.5 and 5.0, respectively.³

In conjunction with the survey assessing perceived pain regimens, all actual opioid prescriptions were identified using the Surgical Opioid QlikView Dashboard, an institutional database that captures all narcotic prescriptions within the discharge electronic medical record. This was conducted for all patients at least 18 years of age who underwent an elective joint arthroplasty of the shoulder, knee, or hip performed by one of the surveyed orthopaedic surgeons. Patients who were not discharged on narcotic pain medications or those who underwent staged arthroplasty or nonarthroplasty procedures were excluded from the analysis. All opioid prescriptions were converted to MMEs, as described above, within the Surgical Opioid QlikView Dashboard.

For continuous data such as opioid MMEs, statistical analysis was conducted using Student t-tests. Chi-square tests were used to analyze categorical data such as the number of opioid prescriptions at discharge. Averages and percentages were reported with their 95% confidence intervals (CIs). Statistical significance was defined as P value <0.05.

Results

A total of 17 orthopaedic surgeons were identified to have performed total joint arthroplasty of the shoulder, hip, or knee within the study period. The principal investigator (S.M.) was excluded to avoid reporter bias, and two surgeons indicated that they did not perform routine arthroplasties. Therefore, the survey was distributed to 14 orthopaedic surgeons. Of those, 11 responded, resulting in a survey response rate of 78.6%. Our institution's opioid database did not capture one surgeon's opioid prescriptions at discharge and was thus excluded from analysis. This resulted in a total of 10 surgeons who were included. Of those, eight surgeons provided their perceived opioid pain protocol, and all 10 detailed their perioperative pain regimen. Among the 10 surgeons, opioid prescriptions from 3127 patients were analyzed.

Orthopaedic surgeons prescribed an average of 826.5 MMEs after elective total joint arthroplasties per surgeon preference, which equates to approximately 551 mg of oxycodone, 207 mg of hydromorphone, and 826.5 mg of hydrocodone. This corresponded to a difference of 594.2 MMEs (396 mg of oxycodone, 149 mg of hydromorphone) between actual and perceived (232.3 MMEs) opioid prescriptions (P < 0.001). 92.4% of patients were prescribed more MMEs than perceived by orthopaedic surgeons. For every 10 MMEs that they perceived they were prescribing at discharge, surgeons in fact prescribed an additional 60.9 MMEs (estimate: 6.09, R²: 0.302, P < 0.001). This corresponded to an additional 40 mg of oxycodone or 15 mg of hydromorphone. Overall, orthopaedic surgeons prescribed on average 15.9 days of opioids (median: 20 days). When accounting for only the physicians who provided their perceived opioid pain protocol, they prescribed on average 15.0 days of opioids (median: 20 days), which was significantly greater than what they perceived (5.3-day supply) (P < 0.001).

Patients who received liposomal bupivacaine preoperatively were prescribed 597 fewer MMEs at discharge (P < 0.001) (Figure 1, A). In addition, 86.2% of the patients who did not receive liposomal bupivacaine were prescribed more than one opioid at discharge as opposed to 20.5% of patients who received liposomal bupivacaine (P < 0.001) (Figure 1, B).

Figure 1.

Chart demonstrating average morphine milligram equivalents (MMEs) prescribed based on adjunctive pain modality (A). Patients receiving liposomal bupivacaine were prescribed 476 MMEs versus 1073 MMEs in patients who did not receive the adjunct (P < 0.001). Chart demonstrating percentage of patients receiving more than one opioid prescription at discharge (B). Liposomal bupivacaine use was associated with fewer opioid prescriptions at discharge (P < 0.001).

Total MMEs prescribed at discharge and the number of opioid prescriptions were also analyzed based on arthroplasty location and the use of preoperative adjuncts (Tables 2 and 3). All patients undergoing total shoulder arthroplasty received preoperative liposomal bupivacaine. Patients undergoing total hip and knee arthroplasty who received liposomal bupivacaine were prescribed significantly fewer MMEs (P < 0.001) and were less likely to receive more than one opioid prescription at discharge (P < 0.001) compared with those without. Total knee arthroplasty patients receiving either liposomal bupivacaine or genicular nerve blocks/cryoneurolysis were prescribed 681 and 831 fewer MMEs, respectively, compared with patients who did not receive the adjunct preoperatively. 96.2% of patients who did not receive an adjunct preoperatively were prescribed more than one opioid prescription at discharge. This decreased to 12.2% in the setting of preoperative liposomal bupivacaine, which attained statistical significance (P < 0.001). All patients receiving genicular nerve blocks or cryoneurolysis received only one opioid prescription at discharge.

Table 2.

Average Morphine Milligram Equivalents Prescribed at Discharge Based on Adjunctive Pain Modality and Arthroplasty Location

Factor or Variable	Liposomal Bupivacaine MME (N)		Difference (95% CI)	P	Genicular Nerve Block or Cryoneurolysis MME (N)		Difference (95% CI)	P
	No	Yes			No	Yes
THA	1079 (1038)	355 (190)	723 [664,783]	<0.001	—	—	—	—
TKA	1171 (1087)	490 (328)	681 [643,718]	<0.001	1171 (1087)	340 (155)	831 [782,882]	<0.001
TSA	—	596 (249)	—	—	—	—	—	—

CI = confidence interval, MME = morphine milligram equivalent, N = number of patients, THA = total hip arthroplasty, TKA = total knee arthroplasty, TSA = total shoulder arthroplasty

Values in bold indicate statistical significance (P < 0.05).

Table 3.

Percentage of Patients Prescribed More Than One Opioid Prescription at Discharge Based on Adjunctive Pain Modality and Arthroplasty Location

Factor or Variable	Liposomal Bupivacaine, % (n/N)		Difference (95% CI)	P	Genicular Nerve Block or Cryoneurolysis MME (N)		Difference (95% CI)	P
	No	Yes			No	Yes
THA	88.5 (919/1038)	16.8 (32/190)	723 [664, 783]	<0.001	—	—	—	—
TKA	96.2 (1046/1087)	12.2 (40/328)	84.0 [80.3, 87.8]	<0.001	96.2 (1046/1087)	0.0 (0/155)	96.2 [93.8, 97.2]	<0.001
TSA	—	26.9 (67/249)	—	—	—	—	—	—

CI = confidence interval, MME = morphine milligram equivalent, n = number of patients who received more than one prescription, N = total number of patients, THA = total hip arthroplasty, TKA = total knee arthroplasty, TSA = total shoulder arthroplasty

Values in bold indicate statistical significance (P < 0.05).

Discussion

The findings of our study support the hypothesis that, after elective total joint arthroplasty, orthopaedic surgeons prescribe markedly more opioids than they perceived to have written. Many institutions, orthopaedic associations, and state legislatures have implemented guidelines to prevent overprescribing opioids in the postoperative setting.^5,8,9 However, there has yet to be literature regarding the surgeon's actual and perceived opioid prescribing patterns.

Orthopaedic surgeons prescribed an average of 594.2 MMEs more than what they initially perceived as their postoperative pain regimen. This equates to additional 80 tablets of oxycodone 5 mg or 75 tablets of hydromorphone 2 mg depending on dosing interval. Variability in perceived versus actual opioid prescriptions may be due to how we derived actual prescriptions. For example, all discharge prescriptions were retrieved from the electronic medical record for each patient and were not retrospectively compared with the prescription monitoring program. Discharge electronic medical records were completed by operating surgeons, advanced care practitioners, or orthopaedic surgery residents who may have not written the opioid prescription. Therefore, prescriptions on the discharge medical record may potentially reflect inaccurate dosing and/or frequency of the written prescription received by patients. This may have contributed to the higher MMEs on actual prescriptions. However, it is standard of practice for the care team to verify discharge prescriptions with the prescribing surgeon before finalizing the discharge reconciliation.

Surgeons prescribed on average a 15.9-day supply of opioids, equating to 826.5 MMEs within our study. This exceeds their perceived duration of supply (average 5.3 days) by 200.0%. Current state guidelines limit opioid prescribing for patients with acute pain to a 5-day supply of the lowest effective dose of an immediate-release schedule II controlled substance within New Jersey.¹⁰ Amendments have been proposed to allow practitioners to prescribe up to a 7-day supply of opioids.¹¹ Legislative verbiage limiting opioid prescriptions to the lowest effective dose may contribute to the ambiguity in prescribing patterns. There has yet to be literature assessing the lowest effective opioid dose in the setting of total joint arthroplasty. In addition, there is limited consensus regarding standards of care for opioid prescribing. Most perioperative pain management algorithms are institutionally based and are not yet universally adopted. Explicit guidelines limiting narcotic prescriptions to MMEs, rather than the lowest effective dose, within the state legislature can potentially reduce opioid overprescribing. Continued medical education training for orthopaedic surgeons and their ancillary staff may also help mitigate opioid overprescribing and discrepancies within actual and perceived opioid prescribing patterns.

Surgeons using liposomal bupivacaine and preoperative cryoneurolysis/genicular nerve blocks prescribed markedly fewer MMEs compared with those who did not. This held true when analyzed based on location of the elective total joint arthroplasty. Incorporating liposomal bupivacaine within regional or periarticular anesthesia decreased narcotic prescriptions by an average of 597 MMEs. Liposomal bupivacaine consists of a DepoFoam delivery system that prolongs its analgesic properties.¹² This can theoretically improve postoperative pain and reduce narcotic prescriptions and consumption. Before our study, the relationship between liposomal bupivacaine and postoperative narcotic prescriptions at discharge was relatively unknown. Most studies assessed liposomal bupivacaine and narcotic consumption during hospitalization. However, their results remain ambiguous with some studies demonstrating reduced total and breakthrough narcotic consumption and others showing similar opioid consumption.^12-15

Surgeons within our study who used preoperative genicular nerve blocks/cryoneurolysis in total knee arthroplasty prescribed on average 831 fewer MMEs. Patients also received markedly fewer opioid prescriptions at discharge. This aligns with previous studies demonstrating that preoperative cryoneurolysis is associated with notable reductions in cumulative opioid consumption after total knee arthroplasty.¹⁶ The potential for both liposomal bupivacaine and cryoneurolysis to reduce MMEs prescribed at discharge can help prevent opioid overprescribing and opioid dependence.

To our knowledge, this is one of the first studies assessing perceived and actual opioid prescribing patterns among orthopaedic surgeons in the setting of elective total joint arthroplasty. However, our study is not without limitations, which are mostly inherent to its survey-based design. First, some questions were formatted with multiple-choice answers, which may inadvertently have caused respondents to select the closest rather than the most accurate answer choice. We hoped to limit this by incorporating “other” within the answer choice and allowing for open-ended responses in subsequent questions. Second, we only included 10 orthopaedic surgeons within our survey, which may limit the generalizability of our data to other surgeons and institutions. Third, we assessed prescriptions at discharge, which do not account for opioid consumption among patients during hospitalization and after discharge, which was beyond the scope of our study. We also recognize that total shoulder, hip, and knee arthroplasty may be associated with varying pain levels, which could have affected our overall results in evaluating perceived versus actual prescriptions. In addition, we acknowledge the potential for observational bias in this survey-based design. Given a national push for reduced narcotic consumption and negative stigma surrounding opioid medications, there is potential for under-reporting of prescribed opioid medications by the participants. However, in the event this is true, the difference between actual and perceived opioid prescribing would be even more inflated. Finally, we did not isolate opioid-tolerant from opioid-naive patients, which may have led to a higher MME for actual prescriptions if a notable number of opioid-tolerant and/or chronic pain patients were included.

Conclusion

Orthopaedic surgeons prescribe markedly more opioids than they perceived in the setting of elective total joint arthroplasty. Patients receiving liposomal bupivacaine and/or cryoneurolysis/genicular nerve blocks preoperatively were prescribed fewer total MMEs and had fewer opioid prescriptions overall at discharge.