Success of Long-acting Anti-inflammatories After Anterior Cruciate Ligament and Meniscal Injury

Anterior cruciate ligament (ACL) injury initiates a biochemical cascade that leads to cartilage degradation and the development of posttraumatic osteoarthritis (PTOA). ACL and acute traumatic meniscus tears have been linked to the development and progression of PTOA. As such, there is an unmet need to identify treatments that may alter the progression of PTOA following ACL meniscus injury. The overarching hypothesis of this project is that intraarticular administration of long-acting anti-inflammatory agents will alter the progression of PTOA following ACL reconstruction.

The current standard of care for patients with combined ACL and meniscus injuries consists of surgical treatment often with a short course of postoperative physical therapy. However, the current mechanically-based standard of care does not address the persistent inflammatory process that promotes cartilage degradation and PTOA progression. The pro-inflammatory stimulation of meniscus cells increases matrix metalloproteinase (MMP) and cytokine activity, and the combination of pro-inflammatory cytokines and compressive loading like what may be seen during sporting and high demand activities further results in degradative enzyme activity and increased production of pro-inflammatory mediators. In this way, the meniscus plays an active role in promoting the cycle of articular cartilage degradation and PTOA progression after ACL reconstruction.

Reducing MMP and cytokine activity after ACL and meniscus injury may alter the progression of PTOA for this at-risk patient population. After ACL injury and reconstruction demonstrate triamcinolone acetonide effectively reduces cartilage degradation, the inflammatory cascade and corresponding cartilage degradation are reinitiated after surgery, hyaluronate treatment 1 week after surgery unsuccessfully mitigates the inflammatory and catabolic processes, and pain and persistent postsurgical cytokine activity at 4 weeks were predictive of inferior knee biomechanics 6 months after surgery. In addition, long-acting agents may provide a greater treatment effect as temporal regulation of cytokine activity may more successfully alter the pro-inflammatory environment than shorter-duration treatments. These results identify that long-acting anti-inflammatory treatment is needed to alter the path of PTOA following meniscus injury and administration 8 weeks after surgery may offer the optimal timing of treatment.

The model whereby femoral shape change and cytokine activity are mediated by a long-acting anti-inflammatory agent (extended-release triamcinolone acetonide) will be tested. Femoral shape changes have been demonstrated after ACL injury and reconstruction, with shape changes in the first 6 months after surgery correlating with subsequent MRI evidence of cartilage degradation and inferior patient-reported outcomes 3 years postoperatively. A Phase 2a, double-blind, placebo-controlled, randomized controlled trial will be performed. The trial will determine if a long-acting anti-inflammatory agent (extended-release triamcinolone acetonide) improves patient-reported outcomes and/or lessens progressive bone shape changes or cartilage breakdown when compared to placebo (saline). Saline was chosen as the placebo as saline has few potential risks and rare adverse events and is the most commonly used placebo treatment option used in knee osteoarthritis research.

• Zilretta (Drug), also known as Extended release triamcinolone acetonide: ZILRETTA is an injectable suspension that delivers 32 mg of triamcinolone acetonide. It is supplied as a single-dose kit containing one vial of ZILRETTA microsphere powder, one vial of 5 mL diluent, and one sterile vial adapter.
• Placebo (Other), also known as Saline: 5 mL normal saline

Primary outcomes

• Change in Bone Shape (Baseline to 4 Months) [Baseline, 4 months]: Using manual segmentation, the volume of the medial femoral condyle will be quantified from 3-Tesla magnetic resonance imaging (MRI) scans performed before and 4 months after the study injection. Medial condyle volume will be expressed as cm3.

Secondary outcomes

• Change in IKDC (Baseline to 4 Months) [Baseline, 4 months, 1 year, 2 years]: The International Knee Documentation Committee (IKDC) scores range from 0-100 with greater scores being indicative of greater self-reported function and reduced pain.
• Change in IKDC (Baseline to 1 Year) [Baseline, 4 months, 1 year, 2 years]: The International Knee Documentation Committee (IKDC) scores range from 0-100 with greater scores being indicative of greater self-reported function and reduced pain.
• Change in IKDC (Baseline to 2 Years) [Baseline, 4 months, 1 year, 2 years]: The International Knee Documentation Committee (IKDC) scores range from 0-100 with greater scores being indicative of greater self-reported function and reduced pain.
• Change in KOOS Global (Baseline to 4 Months) [Baseline, 4 months, 1 year, 2 years]: The Knee injury and Osteoarthritis Outcome Score (KOOS) Global scores range from 0-100 with greater scores being indicative of greater self-reported knee function and reduced pain and symptoms.
• Change in KOOSglobal (Baseline to 1 Year) [Baseline, 4 months, 1 year, 2 years]: The Knee injury and Osteoarthritis Outcome Score (KOOS) Global scores range from 0-100 with greater scores being indicative of greater self-reported knee function and reduced pain and symptoms.
• Change in KOOSglobal (Baseline to 2 Years) [Baseline, 4 months, 1 year, 2 years]: The Knee injury and Osteoarthritis Outcome Score (KOOS) Global scores range from 0-100 with greater scores being indicative of greater self-reported knee function and reduced pain and symptoms.
• Change in ICOAP (Baseline to 4 Months) [Baseline, 4 months, 1 year, 2 years]: The Intermittent and Constant Osteoarthritis Pain (ICOAP) Score is a valid and reliable tool to assess osteoarthritis-related pain. Scores range from 0 to 100, with greater scores indicating worse pain.
• Change in ICOAP (Baseline to 1 Year) [Baseline, 4 months, 1 year, 2 years]: The Intermittent and Constant Osteoarthritis Pain (ICOAP) Score is a valid and reliable tool to assess osteoarthritis-related pain. Scores range from 0 to 100, with greater scores indicating worse pain.
• Change in ICOAP (Baseline to 2 Years) [Baseline, 4 months, 1 year, 2 years]: The Intermittent and Constant Osteoarthritis Pain (ICOAP) Score is a valid and reliable tool to assess osteoarthritis-related pain. Scores range from 0 to 100, with greater scores indicating worse pain.
• Change in CTXII (Baseline to 4 Months) [Baseline, 4 months]: C-terminal cross-linked telopeptides (CTX); CTXII levels measured by ELISA. CTXII is a biomarker of type II collagen breakdown

Sex: All, ages: 18 Years to 40 Years

Inclusion Criteria:

1. Written consent to participate in the study
2. Male or female greater than or equal to 18 years of age and less than 40 years of age
3. Has been consented to undergo arthroscopic ACL reconstruction with partial meniscectomy or meniscal repair
4. Ambulatory and in good general health
5. Willing and able to comply with the study procedures and visit schedules and able to follow verbal and written instructions.
6. Willing to abstain from use of protocol-restricted medications during the study
7. Females and males who have reproductive potential: Must use highly effective contraception for at least 1 month prior to screening and agreement to use such a method during study participation (10 weeks; 4 to 14 weeks after surgery)
8. Demonstrate persistent inflammation defined as synovial fluid IL-1a concentration greater than or equal to 5 pg/mL at the time of surgery

Exclusion Criteria:

1. Known allergic reactions to components of the extended-release triamcinolone acetonide (Zilretta®)
2. Reactive arthritis, rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, or arthritis associated with inflammatory bowel disease
3. History of infection in either knee joint
4. Clinical signs and symptoms of active knee infection or crystal disease in either knee within 1 month of Screening
5. Other surgery or arthroscopy of either knee within 6 months of Screening
6. Intraarticular treatment of any joint with any of the following agents within six (6) months of Screening: any corticosteroid preparation or any biologic agent (e.g., platelet rich plasma (PRP) injection, stem cells, prolotherapy, amniotic fluid injection; investigational or marketed).
7. Intraarticular treatment in either knee with hyaluronic acid (investigational or marketed) within 6 months of Screening
8. Parenteral or oral corticosteroids (investigational or marketed) within 3 months of Screening
9. Inhaled, intranasal or topical corticosteroids (investigational or marketed) within 2 weeks of Screening
10. Females who are pregnant or nursing or plan to become pregnant during the study; men whose female partner plans to conceive during the study
11. Radiographic osteoarthritic changes defined as Kellgren-Lawrence grade 2 or greater (as determined by PI from patient's preoperative X-rays)
12. Inability to read and understand English

Participant flow

Outcome results

• Change in Bone Shape (Baseline to 4 Months) (Primary)
• Change in IKDC (Baseline to 4 Months) (Secondary)
• Change in IKDC (Baseline to 1 Year) (Secondary)
• Change in IKDC (Baseline to 2 Years) (Secondary)
• Change in KOOS Global (Baseline to 4 Months) (Secondary)
• Change in KOOSglobal (Baseline to 1 Year) (Secondary)
• Change in KOOSglobal (Baseline to 2 Years) (Secondary)
• Change in ICOAP (Baseline to 4 Months) (Secondary)
• Change in ICOAP (Baseline to 1 Year) (Secondary)
• Change in ICOAP (Baseline to 2 Years) (Secondary)
• Change in CTXII (Baseline to 4 Months) (Secondary)

Adverse events

Time frame: Only 1 participant was enrolled in this study. Based on the low enrolment number, no data is reported here in order to protect and maintain participant privacy/confidentiality.

• Study Protocol and Statistical Analysis Plan (PDF, 2022-11-16)

• Austin Stone, MD, PhD, Study director, University of Kentucky