Did you know that your own blood contains powerful healing factors that can be concentrated and injected to repair damaged tissues? Platelet-rich plasma (PRP) injection involves extracting your own blood, concentrating the platelets through centrifugation, and injecting this concentrated solution into injured tissues. The concentrated platelets contain growth factors, including platelet-derived growth factor (PDGF), transforming growth factor beta (TGF-β), and vascular endothelial growth factor (VEGF), which stimulate tissue repair and regeneration. Singapore orthopaedic clinics prepare PRP using double-spin centrifugation methods, achieving platelet concentrations several times higher than normal blood levels.
The procedure takes approximately 45-60 minutes from blood draw to injection completion. Your orthopaedic doctor draws 30-60ml of blood, processes it in a centrifuge for 12-15 minutes, and injects the resulting 3-8ml of concentrated plasma directly into the treatment area under ultrasound guidance.
How PRP Works in Tissue Healing
Platelets release alpha granules containing growth factors within 10 minutes of injection into damaged tissue. These growth factors trigger a cascade of cellular responses, including the migration of mesenchymal stem cells, collagen production, and angiogenesis (the formation of new blood vessels). The inflammatory phase peaks at 48-72 hours post-injection, followed by a proliferative phase that lasts 2-6 weeks.
The concentrated growth factors specifically target:
- Type I and III collagen synthesis in tendons
- Chondrocyte proliferation in cartilage
- Osteoblast activation in bone healing
- Fibroblast recruitment for ligament repair
Ultrasound studies show increased tissue thickness and improved fibre alignment starting at week 4 post-treatment, with continued remodelling up to 6 months.
Conditions Treated with PRP
Tendon Injuries
Tennis elbow (lateral epicondylitis)—often treated by an elbow specialist in Singapore—may be considered for PRP injection when conservative treatments have not provided relief after 6 months. The injection targets the insertion of the extensor carpi radialis brevis tendon, with patients potentially experiencing pain reduction starting at week 6-8. Achilles tendinopathy treatment may involve 2-3 injections spaced 4 weeks apart, targeting the mid-portion or insertional regions based on the location of the pathology.
Rotator cuff tears and tendinopathy may be considered for PRP when partial tears measure less than 1cm. The supraspinatus tendon is injected directly under ultrasound guidance, with post-injection rehabilitation commencing after 48 hours of rest.
Joint Conditions
Knee osteoarthritis may show improvement with intra-articular PRP injection. A standard protocol involves three injections at 2-week intervals, with each injection containing 5-8ml of PRP. Hip osteoarthritis treatment requires fluoroscopic or ultrasound guidance for accurate intra-articular placement.
Ankle joint arthritis may respond in post-traumatic cases where cartilage damage remains focal rather than diffuse.
Ligament Injuries
MCL (medial collateral ligament) sprains may heal with PRP injection at the site of maximum tenderness. The injection is performed 7-10 days post-injury, after the acute inflammatory phase has subsided. Plantar fasciitis treatment focuses on the medial calcaneal insertion, with patients advised to avoid weight-bearing for 48 hours after the injection.
The PRP Preparation Process
Blood collection utilises an 18-to 21-gauge needle in citrate-containing tubes to prevent clotting. The first centrifugation spin (at 1500 rpm for 5 minutes) separates red blood cells from the plasma. After transferring the plasma and buffy coat layer to a second tube, the second spin (3500 rpm for 10 minutes) concentrates the platelets.
Leukocyte-rich PRP (L-PRP) includes white blood cells and shows a stronger inflammatory response, while leukocyte-poor PRP minimises inflammation. An orthopaedic specialist selects the preparation based on the specific condition: L-PRP for chronic tendinopathies and P-PRP for intra-articular injections.
PRP preparation typically achieves:
- Platelet count: 1,000,000-1,500,000 platelets/μL
- Volume: 3-8ml depending on treatment area
- pH: 7.0-7.4
- Absence of red blood cell contamination
What Happens During Treatment
Pre-procedure preparation includes stopping anti-inflammatory medications 5 days before treatment, as NSAIDs inhibit platelet function. The treatment area is prepared with an antiseptic solution containing chlorhexidine or iodine.
During injection, the orthopaedic specialist uses ultrasound to visualise needle placement in real-time. For tendon injections, the needle penetrates the tendon sheath and deposits PRP along the degenerative areas using a peppering technique, which involves multiple passes through the tendon without removing the needle. Joint injections follow standard arthrocentesis landmarks with single-point deposition.
Post-injection protocol includes:
- Ice application for 20 minutes every 2 hours for the first 48 hours
- Paracetamol for pain control (avoiding NSAIDs)
- Relative rest for 48-72 hours
- Gentle range of motion exercises starting on day 3
- Progressive loading program beginning week 2
Recovery Timeline and Rehabilitation
Days 1-3 involve an inflammatory response with an expected increase in pain and swelling. The treatment area remains tender with visible swelling in superficial injection sites. Movement stays within a pain-free range without requiring stretching or strengthening exercises.
Weeks 1-2 mark the early proliferative phase. Pain gradually decreases below pre-injection levels. Gentle stretching begins with 15-30 second holds, three repetitions daily. Isometric strengthening starts at 30% maximum voluntary contraction.
Weeks 3-6 show accelerated tissue remodelling. Progressive resistance exercises progress from 50% to 75% of the pre-injury load. Functional movements specific to activities begin with careful monitoring of symptoms.
Weeks 6-12: complete the remodelling phase. Sport-specific or occupational activities resume gradually. Full loading typically returns by week 12, though complete tissue remodelling continues for 6 months.
💡 Did You Know?
PRP contains not only platelets but also fibrin, fibronectin, and vitronectin – proteins that create a biological scaffold supporting new tissue growth and providing mechanical strength during healing.
Factors Affecting Treatment Success
Age influences growth factor concentration, with platelet counts naturally declining with age. Younger patients typically achieve higher platelet concentrations and more robust healing responses.
Chronic conditions show a slower response compared to acute injuries. Degenerative changes visible on MRI, including tendon thickening or intrasubstance tears, may require multiple injection sessions.
Smoking reduces platelet function and growth factor release, thereby compromising treatment effectiveness. Patients who smoke show delayed healing responses compared to non-smokers.
Diabetes affects growth factor signalling, particularly in patients with poor blood sugar control. Optimising blood sugar levels before PRP treatment may improve outcomes.
Physical activity level post-treatment significantly impacts results. Patients following structured rehabilitation protocols achieve better outcomes than those returning to activities without guidance.
Combination Treatments
PRP combined with hyaluronic acid for knee osteoarthritis provides both immediate viscosupplementation and long-term regenerative effects. The typical protocol alternates weekly injections: hyaluronic acid is administered in weeks 1 and 3, and PRP is administered in weeks 2 and 4.
Prolotherapy, preceded by PRP by 2 weeks, creates an inflammatory environment that may enhance platelet activation. Dextrose prolotherapy may be beneficial in cases with ligamentous laxity that accompanies tendinopathy.
Physical therapy modalities complement PRP injection:
- Eccentric strengthening exercises starting week 3
- Shockwave therapy begins in week 6 for tendinopathies
- Manual therapy for joint mobilisation after week 2
What Our Orthopaedic Specialist Says
PRP injection works through biological healing rather than simply masking symptoms. The treatment harnesses your body’s own healing factors, making it particularly suitable for patients seeking alternatives to corticosteroid injections or surgery.
Patient selection remains important: partial-thickness tears respond better than complete ruptures, and early-stage arthritis shows greater improvement than bone-on-bone changes. The ultrasound examination during consultation helps determine tissue quality and assesses the feasibility of injection.
Post-injection compliance with rehabilitation determines long-term success. Patients who rush back to activities often experience incomplete healing, whereas those who follow graduated return-to-activity protocols achieve lasting results.
Commonly Asked Questions
How painful is a PRP injection?
The blood draw feels similar to routine blood tests. The injection itself causes moderate discomfort, lasting 5-10 minutes, comparable to that of a corticosteroid injection. Local anaesthetic mixed with PRP reduces injection pain, though some healthcare professionals avoid this to prevent interference with platelet function.
Can PRP be repeated if the first injection doesn’t work?
Second injections may be administered 6-8 weeks after the first if partial improvement is observed. Complete non-responders after 12 weeks may have an underlying pathology that is unsuitable for PRP, requiring an MRI reassessment. Treatment protocols may limit injections to 3 per year for the same condition.
Does PRP work for complete tendon tears?
Complete tears require surgical repair by a dedicated joint or shoulder specialist in Singapore, as PRP cannot bridge tissue gaps beyond 5mm. However, PRP augmentation during surgical repair may enhance healing, particularly in revision surgeries or when working with poor-quality tissue.
What activities should I avoid after PRP?
Activity restrictions following PRP should be discussed with your healthcare professional. They can provide guidance on appropriate timing for resuming various activities based on your specific treatment and condition.
How long do PRP effects last?
Clinical improvement may persist for 12 to 24 months in tendinopathies. Osteoarthritis patients may require annual injections. Some patients achieve long-term resolution, particularly those with acute injuries treated early.
Putting This Into Practice
- Schedule PRP injection during periods when you can modify activities for 6-8 weeks, avoiding important competitions or work deadlines
- Arrange transportation for treatment day, as driving post-injection immediately may be uncomfortable for knee, ankle, or shoulder treatments
- Prepare ice packs and acetaminophen at home before your appointment, ensuring adequate pain management without NSAIDs
- Document pain levels daily using a 0-10 scale to track improvement patterns and guide rehabilitation progression
- Follow the rehabilitation protocol as recommended by your healthcare professional, resisting the temptation to accelerate return to activities when early improvement occurs
When to Seek Professional Help
- Persistent pain lasting more than 3 months despite conservative treatment
- Recurrent tendon injuries in the exact location
- Joint pain with morning stiffness exceeding 30 minutes
- Partial tendon tears are visible on MRI or ultrasound
- Failed corticosteroid injections with temporary or no relief
- Swelling that persists beyond 72 hours post-injury
- Mechanical symptoms like locking or catching in joints
- Night pain disrupting sleep patterns
Conclusion
PRP injection utilises concentrated growth factors derived from your blood to stimulate biological healing in tendons, ligaments, and joints. Treatment success requires proper patient selection, precise injection technique, and strict adherence to post-injection rehabilitation protocols over 12 weeks.
If you’re experiencing persistent tendon pain, joint arthritis symptoms, or recurrent ligament injuries, an orthopaedic specialist can evaluate your condition and determine if a PRP injection is suitable for your specific pathology.
