Self-Reported Metal Allergy and Early Outcomes After Total Knee Arthroplasty.

The impact of self-reported metal allergy (SRMA) in total knee arthroplasty (TKA) remains controversial. In the absence of objective tests, SRMA is often used as a screening tool for implant selection. The objective of this study was to determine the effect of SRMA on early outcomes after TKA. Between 2010 and 2014, 168 patients with SRMA underwent TKA; 150 (89%) received nickel-free implants, and 18 (11%) received cobalt-chrome implants that contained nickel. Mean age was 67 years, and 95% were female. A cohort of 858 TKA patients (mean age, 68 years) without SRMA matched by sex served as the control group. Outcomes included Knee Society Score (function [KSS-F] and knee [KSS-K]), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, knee flexion, further surgery, and complications. No differences were seen in KSS-F and KSS-K between patients with and without SRMA. The mean WOMAC pain scores were 89.1 for patients with SRMA and 85.2 for patients without SRMA (P=.030). Stiffness and physical function scores were similar. Knee flexion was similar. No differences were found between nickel-free and cobalt-chrome SRMA groups. Patients with SRMA and those without demonstrated similar early functional outcomes. Patients with SRMA who received standard cobalt-chrome implants had no significant difference in functional outcomes compared with patients with nickel-free implants. Better identifiers of patients at risk for adverse events due to implant material are needed. [Orthopedics. 2019; 42(6):330-334.].

Oral Opioids Are Overprescribed in the Opiate-Naive Patient Undergoing Total Joint Arthroplasty.

INTRODUCTION: The opioid epidemic in the United States continues to escalate and contribute to potentially preventable deaths. Because many opioid addictions begin with prescription medication, focus on limiting exposure and decreasing availability are essential. This study identifies the average number of opioid pills consumed following primary total knee and hip arthroplasty (TKA and THA) at our institution in opiate-naive patients to provide an estimate of medication required. We hypothesized that the average number of pills consumed for both TKA and THA was significantly less than the amount prescribed at discharge. METHODS: We prospectively evaluated 99 consecutive patients undergoing primary TKA (51) and THA (48). Patient characteristics and opioid prescription information were pulled from review of medical records. Patients brought remaining pain medications to their first follow-up visit (30 days). We calculated the number of pills consumed. Pill consumption was converted into opioid morphine equivalents. Current pain level and the need for pain medication refill were assessed. RESULTS: Median number of pills prescribed over 30 days was 90 for both TKA and THA. Median number of pain pills consumed was 67 in TKA patients and 37 in THA patients (P < 0.001). Higher oral morphine equivalent consumption was seen in TKA patients compared with THA patients. Mean pain scores of TKA and THA patients were 3.2 and 1.8, respectively (P = 0.002). Also, TKA patients were 5 times more likely to require a refill (P = 0.006) compared with THA patients. DISCUSSION: Pain medication was significantly overprescribed by more than 34% in TKA and 140% in THA. Prescribing practices of narcotic pain medications following total joint arthroplasty result in significantly excess amount of opioids available for potential abuse.

Standardized Opioid Prescription Protocol Reduces Opioid Consumption After Total Joint Arthroplasty.

Previous studies demonstrate routine overprescription of pain medications after total joint arthroplasty (TJA). A standardized reduced opioid prescription protocol for TJA was initiated at our institution, which we hypothesized would lead to a reduction in opioid consumption compared with patients who had surgery before initiation of the new protocol. METHODS: We evaluated 97 consecutive opioid-naive patients undergoing primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) using a standardized opioid prescription protocol (standardized group). A control subject group consisted of 99 patients undergoing TKA and THA just before the adaptation of the standardized prescribing protocol (historic group). Postoperatively, patients brought their remaining pain medication to their 1-month follow-up visit. The number of pills consumed was counted and converted into oral morphine equivalents (OME). Current pain level and the need for pain medication refill was assessed. RESULTS: Among TKA patients, mean opioid consumption in the standardized group (48.5 pills; 432 OME) was markedly less than the historic group (76.2 pills; 903 OME) (both P < 0.01). Refills were required in 50% of the standardized group and 29% of the historic group (P = 0.038). Average pain scores for the standardized and historic groups were 2.3 and 3.2, respectively (P = 0.057). Among THA patients, mean opioid consumption in the standardized group (19.1 pills; 200 OME) was markedly less than the historic group (41.3 pills; 504 OME) (both P < 0.01). Refills were required in 16% of the standardized group and 8% of the historic group (P = 0.263). Average pain scores for the standardized and historic groups were 1.7 and 1.8, respectively (P = 0.608). DISCUSSION: Initiation of a standardized opioid prescribing protocol after TJA for opioid-naive patients led to a reduction in opioid consumption, but resulted in an increased need for refills.

Efficacy of Intravenous Acetaminophen for Postoperative Analgesia in Primary Total Knee Arthroplasty.

BACKGROUND: The use of intravenous acetaminophen has seen recent enthusiasm as one component of a multimodal approach to pain management. However, there is a lack of literature examining the efficacy of intravenous acetaminophen for pain control in total joint arthroplasty. The purpose of this study was to evaluate the efficacy of intravenous acetaminophen following primary total knee arthroplasty. METHODS: This is a retrospective review of 38 patients undergoing primary total knee arthroplasty by a single surgeon at one institution. Twenty-five patients received 1 gram of intravenous acetaminophen every 6 hours for 24 hours postoperatively. Thirteen patients received no additional intervention. Exclusion criteria were bilateral or concomitant procedures, allergy to medications included in the standard postoperative protocol, neuropathy or sensory disturbances, history of opioid dependence or abuse, deviations from protocol, revision procedures, and incomplete data. Primary outcomes were change in patient-reported visual analog scale (VAS) pain score, overall opioid consumption measured in morphine milligram equivalents, and hospital length of stay. RESULTS: We found no difference in length of stay, at 3.3 days in the control group and 2.9 days in the intervention group. There was a significant difference in VAS score between 16 and 24 hours. There was a statistically significant decrease in overall opioid consumption in the intravenous acetaminophen group 37.6 vs 18.6 morphine milligram equivalents. CONCLUSION: Intravenous acetaminophen is effective in significantly reducing opioid requirements in the first 24 hours following primary total knee arthroplasty. Additionally, there is a clinically significant decrease in VAS pain scores in patients receiving this intervention.