What is the role of rosehip extract, Devil's claw (Harpagophytum procumbens) extract, Sodium hyaluronate, and Aflapin in managing knee pain?

Role of Rosehip Extract, Devil's Claw, Sodium Hyaluronate, and Aflapin in Knee Pain

Of these four agents, only sodium hyaluronate (hyaluronic acid) has guideline support for knee osteoarthritis, though recent high-quality evidence has significantly weakened this recommendation, while rosehip extract and Devil's claw have limited clinical trial data showing modest pain reduction, and Aflapin lacks any mention in major guidelines or quality evidence.

Sodium Hyaluronate (Hyaluronic Acid)

Current Guideline Position

• The American College of Rheumatology (2012) provides no recommendation for or against intra-articular hyaluronate use, reflecting uncertainty about its clinical benefit 1
• The 2021 VA/DoD guidelines recommend offering intra-articular viscosupplementation for persistent knee OA pain when analgesics and non-pharmacological treatments have failed 1
• However, more recent 2025 evidence-based analyses from the American Academy of Orthopaedic Surgeons and American College of Rheumatology/Arthritis Foundation conditionally recommend against routine use due to inconsistent evidence and minimal clinical benefit 2

Evidence Quality and Effect Size

• EULAR guidelines (2000) found evidence supporting hyaluronic acid for pain reduction (Level 1B) and functional improvement (Level 1B), with effect sizes ranging from 0.04 to 0.9 in three randomized controlled trials 1
• The number needed to treat is 17 patients, meaning 16 patients receive no benefit for every 1 patient who does 2
• When limited to trials with low risk of bias, meta-analyses show that hyaluronic acid's effect size compared to saline injections approaches zero 2

Practical Limitations

• Pain relief may last several months (longer than corticosteroids), but this is offset by slower onset of action and the requirement of 3-5 weekly injections with associated logistical and cost burdens 1, 2
• The mechanism by which exogenous hyaluronate exerts therapeutic effects in arthritic joints remains unknown 3
• If a patient had inadequate response to viscosupplementation, stop it immediately and transition to intra-articular corticosteroid injections, which have Level 1B evidence for effective short-term pain relief 2

Devil's Claw (Harpagophytum procumbens)

Clinical Evidence

• An uncontrolled multicentre study of 75 patients with hip or knee arthrosis using 2400 mg daily extract (50 mg harpagoside) showed WOMAC total score reduction of 22.9% and VAS pain score decreases of 24.5-25.8% over 12 weeks 4
• A 2006 systematic review concluded that while Devil's claw appeared effective for pain reduction, the methodological quality of existing trials was generally poor, and a definitive answer to efficacy and safety questions requires high-quality trials 5
• A 2012 review found strong clinical evidence for pain reduction but noted that Devil's claw has not been rigorously tested in in vitro and in vivo models, and high-quality clinical trials are needed 6

Dosing and Safety

• Extract preparations should contain at least 50 mg harpagoside in the daily dose for treatment of pain based on evidence-based recommendations 7
• Only minor adverse events reported (dyspeptic complaints, sensation of fullness), with lower risk than NSAIDs, though long-term safety assessment is limited by small study populations 4, 5
• No major guidelines (ACR, EULAR, VA/DoD) recommend Devil's claw for knee osteoarthritis, reflecting insufficient high-quality evidence

Rosehip Extract (Rosa canina)

Available Evidence

• A randomized, double-blind, placebo-controlled crossover trial of 94 patients with hip or knee OA using 5g daily showed significant WOMAC pain reduction (p<0.014) after 3 weeks and significant reductions in disability (p<0.018), stiffness (p<0.038), and global severity (p<0.035) after 3 months 8
• The same study showed significant reduction in rescue medication consumption (p<0.027) 8
• A 2012 nutraceutical review noted that pomegranate and green tea only have preclinical evidence, while rosehip was not specifically addressed, suggesting limited research attention 6

Clinical Positioning

• No major clinical guidelines (ACR, EULAR, VA/DoD) mention or recommend rosehip extract for knee osteoarthritis
• The single positive trial provides preliminary evidence but requires replication in larger, high-quality studies before clinical recommendation

Aflapin

Evidence Gap

• Aflapin is not mentioned in any of the major clinical guidelines reviewed (EULAR 2000, ACR 2012, AGS 2001, VA/DoD 2021) 1
• No research studies in the provided evidence base address Aflapin for knee pain or osteoarthritis
• Without guideline support or quality clinical trial data, Aflapin cannot be recommended for knee pain management

Recommended Treatment Algorithm Instead

First-Line Treatments (Strong Evidence)

• Land-based exercise programs with joint-specific strengthening (effect sizes -0.58 to 1.05) 2
• Weight loss for overweight patients 2, 9
• Topical NSAIDs for knee OA with fewer systemic side effects 1, 2
• Acetaminophen up to 3-4g daily in divided doses 1, 2, 9

Second-Line Treatments

• Intra-articular corticosteroid injections provide effective pain relief for up to 3 months with strong evidence (effect size 1.27 for pain relief over 7 days) 1, 2
• Oral NSAIDs when not contraindicated 1
• Structured physical therapy programs 1, 2

Critical Pitfalls to Avoid

• Do not use oral narcotics including tramadol, as they cause notable increase in adverse events without consistent improvement in pain or function 2
• Avoid arthroscopic debridement or partial meniscectomy for primary osteoarthritis, as it provides no benefit and delays definitive treatment 2
• For patients with refractory pain and radiological deterioration when conservative management has failed, refer for joint replacement 2