The purpose of this study is to assess the benefit of OMS103HP for Injection (OMS103HP) compared with vehicle irrigation solution for prevention of pain and pain relief in subjects undergoing meniscectomy. The pain relief is assessed based on Visual Analog Scale (VAS) Pain Scores in the immediate 24-hour postoperative period and for seven days postoperatively.

Inclusion Criteria:

1. Subject has voluntarily signed informed consent form, including HIPAA Authorization.
2. Subject is ≥ 18 and ≤ 75 years of age.
3. Subject is in good general health with a traumatic or degenerative meniscal cartilage injury (full tear) that occurred at least 14 days prior to the day of arthroscopic surgery.
4. Subject is undergoing unilateral meniscectomy.
5. Subject's physical examination is within normal limits or examination is clinically nonsignificant as determined by the Investigator, and subject is in good general health.
6. Subject's laboratory evaluations are within normal limits or evaluations are clinically nonsignificant as determined by the Investigator.
7. Subject, if female and of childbearing potential (i.e., not surgically sterilized or post-menopausal greater than one year) agrees to use an effective method of birth control for the duration of her study involvement.
8. Subject is at minimal risk from anesthesia and is classified according to the American Society of Anesthesiologists Physical Status Classification as either PS-1 (a normal healthy patient) or PS-2 (a patient with mild systemic disease that results in no functional limitation). See Appendix VI.
9. Subject agrees to refrain from taking the excluded medications listed in Exclusion Criteria through postoperative Day 7 (except for authorized analgesic medications) unless written permission has been granted by Omeros.
10. Subject is able to be proficient in the use of the ePRO device (documented at the site).

Exclusion Criteria:

1. Subject with significant arthritis (>2 on the Kellgren-Lawrence Scale).

2. Subject with a history of reactive synovial disease.

3. Subject with current, or history of, complex regional pain syndrome (Type I, i.e., reflex sympathetic dystrophy, or Type II, i.e., causalgia), chronic pain, attendance at a chronic pain clinic, or neurologic disorder associated with any sensory deficit of the lower extremities.

4. Subject with current, or history of fibromyalgia.

5. Subject taking ANY ANALGESIC (including salicylates, opioids, propoxyphene, etc.) on the day of surgery from 12:00 A.M. until after the procedure, except for medications authorized by the Investigator or delegated staff.

6. Subject taking any of the following medications within the stated time frames prior to the day of surgery.

   1. Amitriptyline within 30 days
   2. More than two doses of sumatriptan, (or any other drug in the triptan class), ondansetron, or other prescription serotonergic or histaminic drug within 14 days
   3. More than two doses of any oral, parenteral, or intravenous steroids (e.g., dexamethasone for antiemetic prophylaxis) within 3 months
   4. More than two doses of oxymetazoline or other nasal decongestant/cold/cough/allergy medication (including loratadine) within 7 days
   5. More than two doses of ketoprofen or other NSAID (including COX-2 inhibitors) within 7 days (except for piroxicam, as indicated below)
   6. Subject who has taken more than two doses of opioid pain medication within the prior seven days of surgery or chronic use of opioid pain medications for greater than 6 weeks within the prior year
   7. More than two doses of piroxicam within 14 days
   8. Subject with a history of intra-articular corticosteroid injection in the operative knee within the two months prior to the meniscectomy

7. Subject expected to undergo any of the following procedures concurrent with meniscectomy:

   1. Arthroscopic patellar tendon debridement
   2. Patellar alignment
   3. Lateral or retinacular release
   4. Excision synovectomy (minor synovectomy to improve arthroscopic visualization is acceptable)
   5. Concurrent ligamentous procedure
   6. Microfracture
   7. Abrasion arthroplasty
   8. Chondral transplantation
   9. Use of more than three portals

8. Subject with allergies to any of the individual ingredients in OMS103HP, to related compounds (e.g., other NSAIDs or tricyclic antidepressants), or to opioid analgesics.

9. Subject who is pregnant or breast-feeding.

10. Subject with Worker's Compensation claim(s) under dispute or mediation.

11. Subject with history of drug or alcohol abuse.

12. Subject who has taken or used an investigational drug or device within 30 days prior to the day of surgery.

13. Subject with a history or presence of systemic disease (renal, hepatic, psychiatric, etc.), which in the opinion of the Medical Monitor and the Principal Investigator, may place the subject's health at risk by participation in the study.

14. Subject who is expected to receive a regional block for analgesia for this procedure.

15. Subject who is considered by the Investigator for any reason to be an unsuitable candidate for receipt of an investigational drug.