Medicines and injections
Do hyaluronic acid injections regenerate cartilage?
The familiar name “cartilage injection” can misrepresent the treatment goal.
At a glance
- “Cartilage injection” does not mean cartilage regeneration.
- Discuss guidelines and realistic benefit.
- Review the product, response and need for repetition.
A knee injection called a cartilage injection may sound as though cartilage will grow back. Hyaluronic acid injections are used with the aim of improving symptoms and function. Describing them as restoring the original joint can create unrealistic expectations.
Hyaluronic acid: expectations and response
- 01
Purpose
Aim to improve pain and function
- 02
Evidence
No promised regrowth; limited average benefit
- 03
Review
Daily benefit, cost and repetition
Three panels: purpose, evidence and actual response
A joint-fluid ingredient is not proof of clinical benefit
Hyaluronic acid is present in normal joint fluid. Lubrication may help explain the proposed mechanism, but a mechanism alone does not guarantee pain relief in patients.
The goal is symptom control. It does not establish regrowth of worn cartilage in ordinary knee osteoarthritis. Disease severity and individual response vary.
Guidelines are cautious about routine use
AAOS does not recommend routine use for knee osteoarthritis, and NICE recommends not offering it. These positions reflect assessments of average effect and clinically meaningful benefit.
Individual discussions may consider local practice and suitability of alternatives, but injections are not a mandatory treatment sequence. Compare expected benefit and cost with other options.
Products and regimens differ
Formulation, number of injections, authorizations and insurance rules differ. An old article or another patient’s schedule does not automatically apply to your prescription.
Report possible infection, allergies, anticoagulants and recent treatment. Local pain or swelling can occur afterwards; worsening or persistent symptoms need review.
Check whether you actually benefit
Compare walking, stairs, sleep and pain medicine use before and after treatment. Symptoms fluctuate naturally, so a single change does not establish long-term benefit.
If benefit is small, reconsider exercise and other options before repeating or increasing expense. A newly hot, swollen knee or inability to bear weight needs prompt assessment; do not wait for the next injection.
Can I have a joint injection before knee replacement?
If you are planning knee replacement, tell the surgical team what was injected into that knee and when. Discuss avoiding corticosteroid or hyaluronic acid joint injections during the three months before surgery. If you have already had an injection, ask your surgeon about the timing of surgery rather than cancelling it yourself.
A 2019 study of 58,337 knee replacements found higher odds of infection around the prosthesis when an injection had been given within the preceding three months. The odds ratio was 1.21 for corticosteroid and 1.55 for hyaluronic acid. This was an observational study of insurance records. These figures do not establish causation or predict an individual patient’s infection risk.
Is hyaluronic acid covered by Korean health insurance?
The medicine may be covered when knee osteoarthritis is radiographic KL grade 1–3 and treatment meets the product’s authorized use and Korean reimbursement criteria. The number of injections and the interval before a repeat course must be checked for the specific formulation.
For example, sodium hyaluronate 20 mg has a course of three weekly injections, while the 25 mg formulation has five weekly injections. For these two formulations, a repeat course is covered when the previous course was effective and at least six months have passed. Single-injection cross-linked formulations follow their own labeling and reimbursement criteria. Please check the injection’s name and the dates of your previous treatment.
Common Questions
Will the joint space widen?
This is symptom-oriented treatment, not a guarantee that a narrowed osteoarthritic joint space will return to normal.
Can it fail to help?
Yes. Average benefit and individual response are inconsistent, so expectations should be discussed beforehand.
How many hyaluronic acid injections can I receive?
There is no single lifetime limit shared by every product. Sodium hyaluronate 20 mg is given as three weekly injections and 25 mg as five weekly injections per course. Reimbursement for a repeat course of these two formulations requires previous benefit and an interval of at least six months. Other formulations follow their own criteria; reassess the need to repeat treatment if it has not helped.
Evidence and references
01When to seek medical care
Each warning sign is a separate reason to seek care. Follow the action below if any one applies.
Emergency department · call 119 in Korea
- Call 119 for sudden breathlessness or chest pain, severe faintness or loss of consciousness. Do not wait for calf swelling to appear.
- Go to an emergency department if you suddenly cannot bear any weight, or if an injured knee swells rapidly or looks deformed. A cold or numb foot after injury also needs immediate assessment.
- Seek emergency care for a hot, swollen and severely painful joint with high fever, shaking chills, confusion or inability to bear weight.
- With back or leg pain, go immediately to an emergency department for new difficulty passing urine, loss of bladder or bowel control, or numbness around the genitals or anus. Severe or rapidly worsening weakness or numbness in both legs also needs immediate assessment.
Same-day assessment
- Arrange assessment today for a newly hot, swollen joint, sudden severe pain, or a knee locked so that it cannot fully straighten. Joint infection can occur without fever.
- Have new swelling or pain in one calf assessed today for a possible blood clot. Call 119 immediately if breathlessness or chest pain develops.
- Severe knee pain or a new limp in a growing adolescent may come from a hip condition such as slipped capital femoral epiphysis. Stop walking and sport and arrange assessment today. Go directly to emergency care if they cannot bear weight.
- Stop running and seek assessment today for new recurring groin pain, pain with walking or at night, or a limp. A femoral neck stress fracture needs to be considered. Keep weight off the painful leg until assessed. Go to emergency care if you cannot bear weight.
Book an outpatient appointment
- If none of the warning signs above is present, book an appointment for pain lasting a few weeks, repeated swelling or reduced daily activity and exercise.