PRP Injections for Pain in Quadriceps Tendon (Tendinopathy)
- Mustafa Alnaib
- May 7
- 7 min read
Quadriceps tendinopathy is a degenerative condition that affects the tendon connecting the quadriceps muscle group to the superior aspect of the patella. It is most commonly observed in individuals engaged in repetitive or high-load activities involving the knee, such as jumping, sprinting, or abrupt directional changes. The condition may present initially with localised pain and stiffness, and can progress to persistent discomfort and functional limitations if not managed appropriately.
Platelet-rich plasma (PRP) therapy is a biologically based intervention that has been increasingly integrated into musculoskeletal practice, particularly for chronic tendon disorders. PRP involves the injection of autologous blood components, concentrated to elevate platelet levels and associated growth factors, into the site of tendon pathology. In the context of quadriceps tendinopathy, PRP represents a potential option for patients with symptoms unresponsive to conventional conservative measures.
This article provides an overview of quadriceps tendinopathy and examines the rationale, procedure, and clinical considerations associated with PRP injection therapy.
Understanding Quadriceps Tendinopathy
The quadriceps tendon is a robust, fibrous structure that connects the quadriceps femoris muscle group to the superior pole of the patella. It plays a critical role in knee extension, particularly during weight-bearing activities such as running, jumping, and squatting. Quadriceps tendinopathy refers to a chronic degenerative process within this tendon, often resulting from repetitive mechanical overload.
Unlike acute tendon injuries that involve inflammation (tendinitis), quadriceps tendinopathy is characterised by collagen disorganisation, neovascularisation, and an absence of inflammatory cells. It typically arises in response to cumulative microtrauma that exceeds the tendon’s capacity for repair. Contributing factors may include sudden increases in training intensity, poor biomechanics, inadequate recovery periods, and age-related tendon degeneration.
Patients often report anterior knee pain, particularly at the top of the patella, which may worsen with physical activity and improve with rest. Stiffness after periods of inactivity, tenderness to palpation, and discomfort during resisted knee extension are common clinical features.
Diagnosis is usually based on clinical history and physical examination. Imaging modalities such as ultrasound and magnetic resonance imaging (MRI) are invaluable in confirming the diagnosis and assessing the extent of tendon involvement. These may reveal thickening of the tendon, hypoechoic areas, and increased vascularity.
Conventional Treatment Approaches
Management of quadriceps tendinopathy typically begins with non-invasive interventions aimed at reducing pain, restoring function, and promoting tendon remodeling. Initial treatment strategies often include activity modification, whereby patients are advised to reduce or avoid movements that exacerbate symptoms, such as jumping, deep squats, or prolonged kneeling.
Nonsteroidal anti-inflammatory drugs (NSAIDs) may provide temporary relief of discomfort, although their effectiveness is often limited in chronic tendinopathy due to the predominantly degenerative, rather than inflammatory, nature of the condition.
Physiotherapy is the cornerstone of conservative management. Eccentric strengthening exercises, in particular, have demonstrated beneficial effects on tendon healing by promoting collagen alignment and improving load tolerance. These are often incorporated into a structured rehabilitation program that may also include isometric exercises, flexibility training, and proprioceptive drills.
Adjunctive therapies such as extracorporeal shockwave therapy, therapeutic ultrasound, and tendon dry needling are sometimes employed, although the evidence supporting their efficacy remains variable.
Despite comprehensive conservative care, a subset of patients may continue to experience persistent symptoms. In these cases, biologic interventions such as PRP therapy may be considered as part of a more advanced management strategy.
What Is PRP Therapy?
Platelet-rich plasma (PRP) therapy is a biologically based treatment that utilises autologous blood products to promote tissue healing and regeneration. The technique involves the collection of a patient's venous blood, followed by centrifugation to separate and concentrate the platelet-rich fraction from the remaining plasma and cellular components.
Platelets are a critical component of the body’s natural healing processes. In addition to their role in coagulation, they contain a wide range of growth factors and cytokines, such as platelet-derived growth factor (PDGF), transforming growth factor-beta (TGF-β), vascular endothelial growth factor (VEGF), and insulin-like growth factor-1 (IGF-1). These mediators are thought to contribute to cellular proliferation, angiogenesis, and matrix synthesis, all of which are essential in the repair of tendon tissue.
There are two principal formulations of PRP: leukocyte-rich PRP (LR-PRP) and leukocyte-poor PRP (LP-PRP). LR-PRP contains a higher concentration of white blood cells and it exerts a more potent inflammatory response, which may be advantageous in certain settings. In contrast, LP-PRP contains fewer leukocytes and is generally associated with a reduced inflammatory profile, potentially offering better tolerability in sensitive tissues. The choice of formulation depends on the clinical context and stage of condition.
PRP therapy is distinguished from corticosteroid injections by its regenerative rather than anti-inflammatory mechanism of action, and it does not carry the same risk of tendon weakening associated with repeated steroid use.
PRP Injections for Quadriceps Tendon (Tendinopathy)
Procedure Overview
PRP injections for quadriceps tendinopathy are typically administered under ultrasound guidance to ensure precise delivery to the affected tendon area. The procedure involves drawing a sample of the patient's blood, processing it to concentrate the platelets, and then injecting the PRP into the site of tendinopathy. Local anesthesia is often used to minimise discomfort during the injection.
Rehabilitation Protocol
Post-injection rehabilitation is crucial for optimising treatment outcomes. A structured rehabilitation program may include:
Immediate Post-Injection (Days 1–3): Limited weight-bearing, rest and avoidance of anti-inflammatory medications to allow the PRP to initiate the healing response.
Early Rehabilitation (Weeks 1–2): Initiation of gentle range-of-motion exercises and isometric quadriceps strengthening exercises.
Progressive Loading (Weeks 3–6): Introduction of eccentric strengthening exercises and gradual return to functional activities, guided by pain levels and functional capacity.
Adherence to a tailored rehabilitation program is essential to facilitate tendon healing and restore function.
Benefits of PRP injections
Platelet-rich plasma (PRP) therapy has been explored as a treatment option for various tendinopathies, including quadriceps tendinopathy. Studies suggest that PRP injections may offer the following benefits:
Pain Reduction and Functional Improvement: A systematic review and meta-analysis indicated that PRP injections could lead to significant improvements in pain and function in patients with chronic tendinopathies, particularly when used as a second-line treatment after the failure of conservative therapies. Link to article published in Pain Medicine
Enhanced Tendon Healing: PRP contains growth factors that may promote tissue regeneration and healing processes within the tendon.
Minimally Invasive Alternative: As a non-surgical intervention, PRP injections present a less invasive option compared to surgical treatments, potentially reducing recovery time and associated risks.
Potential Risks and Considerations in PRP injections
While PRP therapy is generally considered safe, several factors should be taken into account:
Variable Efficacy: The effectiveness of PRP injections can vary depending on the specific tendinopathy being treated.
Lack of Standardisation: Differences in PRP preparation methods, including presence of leukocytes and spinning technique, can lead to inconsistent outcomes. It is important to consult with your doctor regarding different PRP preparations.
Potential Side Effects: Patients may experience localised pain, swelling, or inflammation at the injection site. Although rare, there is also a risk of infection.
Cost and Accessibility: PRP treatments can be expensive and are often not covered by insurance, which may limit accessibility for some patients. At ACTIVATE, we offer affordable MSK services and flexible payment options.
When to Consider PRP Injections in Quadriceps Tendinopathy
Platelet-rich plasma (PRP) injections may be considered for patients with quadriceps tendinopathy under the following circumstances:
Persistent Symptoms Despite Conservative Management: Patients who have not achieved adequate relief from standard treatments such as physical therapy, activity modification, and nonsteroidal anti-inflammatory drugs (NSAIDs) may be candidates for PRP therapy.
Desire to Avoid Surgical Intervention: Individuals seeking non-surgical options due to personal preference or medical contraindications to surgery may consider PRP injections as an alternative.
Contraindications to Other Treatments: Patients who cannot tolerate NSAIDs or corticosteroid injections, or for whom these treatments are ineffective, may benefit from PRP therapy.
Athletic or Occupational Demands: Athletes or individuals with physically demanding occupations who require expedited recovery may consider PRP to potentially enhance healing.
Contraindications and Precautions
PRP therapy may not be suitable for all patients. Contraindications and precautions include:
Active Infection: Presence of systemic infection or infection at the injection site.
Blood Disorders: Patients with platelet dysfunction syndromes, thrombocytopenia, or other hematologic conditions.
Anticoagulant Therapy: Use of anticoagulant medications that cannot be safely discontinued.
Why Choose ACTIVATE Musculoskeletal Clinic for PRP Injections
At ACTIVATE Musculoskeletal Clinic, with locations in Kent and London, we provide a one stop clinic for the treatment of chronic tendon conditions, including quadriceps tendinopathy. Our approach is guided by evidence-based practice and delivered with expertise in musculoskeletal medicine.
We perform ultrasound-guided PRP injections, ensuring precise placement of the injection into the affected tendon tissue. This level of accuracy is crucial for maximising the therapeutic potential of PRP and is complemented by the use of high-quality, standardised preparation systems.
What sets us apart is our commitment to comprehensive care. PRP treatment at ACTIVATE is not offered in isolation but as part of a broader management plan that includes individualised rehabilitation, activity modification strategies, and ongoing clinical oversight.
Whether you are an athlete or an active individual seeking to avoid surgery and regain function, we will guide you through a clear, structured path to recovery. By combining procedural excellence with a deep understanding of tendon pathology and rehabilitation science, ACTIVATE Musculoskeletal Clinic is uniquely positioned to support your recovery and long-term musculoskeletal health.
Summary and Patient Advice
Quadriceps tendinopathy can lead to considerable pain and limit function, especially in active people.
While many improve with rehabilitation and conservative treatments, some continue to face symptoms that impact daily or athletic activities.
Platelet-rich plasma (PRP) injections offer a minimally invasive option, enhancing healing by delivering concentrated growth factors to the affected tendon
PRP is generally well-tolerated, but patients should consider potential risks, preparation variability, and the necessity for post-injection rehabilitation.
Informed decision-making and shared discussions with clinicians are crucial for achieving optimal outcomes.
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About the Author: Dr. Mustafa Alnaib MBChB, MRCS, MSc, FEBOT is an orthopaedic surgeon, musculoskeletal doctor and Clinic Director at ACTIVATE Musculoskeletal Clinic in Kent & London
📍 ACTIVATE Musculoskeletal Clinic – Kent & London
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