Post-Operative Pain Relief: Zynrelef or Periarticular Injections in RATKA

Opioid use is a well-discussed issue in the United States among orthopedic surgeons, as while these drugs are helpful and necessary, they pose the risk of addiction and ultimately should be used as sparingly as possible. By taking a multimodal approach to pain management, this can be successfully achieved. Periarticular injections are currently used to achieve this goal, and 2021 a bupivacaine-meloxicam extended-release periarticular injection (Zynrelef) was introduced and is regularly implemented into RATKAs. Randomized clinical trials found that Zynrelef's use in traditional total knee arthroplasties (TKA) was just as effective as standard periarticular injections in reducing opioid use and pain, but whether Zynrelef works just as well if not better in RATKA is not yet established.

Objectives: (primary and important secondary objectives)

To evaluate the improvement in pain and use of opioids of a patient who received Zynrelef after undergoing RATKA compared to the traditional periarticular injections commonly used. The secondary objective will be documentation of the patient's use of other oral (over-the-counter) OTC pain relievers, such as acetaminophen or NSAIDs (non-steroidal anti inflammatory drugs).

Study Design:

Prospective Cohort Study (double arm)

Setting/Participants:

Patients who have undergone a standard of care RATKA at any Allegheny Health Network facility who consent to filling out a survey addressing their reported outcomes.

Study Interventions and Measures:

Patients will be evaluated with the Numeric Rating Scale (NRS) on postoperative days 1-3. Patients will be given paper forms which will be collected by the physicians at their next postoperative visit. A retrospective review of Epic Electronic Medical Records (EMR) will also be conducted to describe basic demographic characteristics.

Inclusion criteria

Males or females aged 18-89 years

Diagnosed with knee osteoarthritis requiring surgical intervention

Indicated for unilateral RATKA

Exclusion criteria

Pediatric, pregnant, or incarcerated patients

BMI of more than 45 kg/m2

Prolonged opioid use history of >5 mg/day for >1 month

History of contralateral TKA <2 years prior to the index TKA

Type 1 Hypersensitivity to NSAIDs or local anesthetics

Diagnosis of severe renal disease