Two Clinically Distinct Treatments. One Precise Diagnosis.
Osteoarthritis progressively degrades articular cartilage and reduces the quality of synovial fluid within the joint. When this process reaches a point where pain, stiffness, and functional restriction become significant, targeted injectable therapies offer a clinically validated pathway to meaningful and sustained relief.
At Core Body Clinic’s Reading clinic, we offer two distinct injectable options for joint osteoarthritis: hyaluronic acid viscosupplementation and Arthrosamid polyacrylamide hydrogel implantation. These are not interchangeable treatments. Each works through a different biological mechanism, suits a different patient profile, and produces a different duration and character of benefit. Understanding which is appropriate for your condition requires specialist assessment, which we provide before any injection is selected or administered.
Hyaluronic Acid Injections: How They Work
Synovial fluid in a healthy joint contains a high concentration of hyaluronic acid molecules with significant molecular weight and chain length. These properties give synovial fluid its characteristic viscosity, enabling it to absorb compressive load, distribute mechanical stress across the joint surface, and allow smooth, frictionless movement between articular cartilage surfaces.
In osteoarthritic joints, both the concentration and molecular weight of hyaluronic acid decline. The resulting fluid is thinner, less viscous, and far less capable of performing these protective functions. Mechanical friction increases, cartilage surfaces sustain greater wear, and the synovium responds with chronic low-grade inflammation that compounds the degenerative process.
Hyaluronic acid injection, known as viscosupplementation, addresses this directly. A concentrated, high molecular weight HA preparation is delivered into the joint space under ultrasound guidance. This immediately restores lubrication and load distribution within the joint. Over subsequent weeks, the injected HA also signals the joint’s own synoviocytes to upregulate endogenous HA production, extending the benefit beyond the initial viscosupplementation effect. Additionally, HA reduces the concentration of destructive inflammatory enzymes within the joint that accelerate cartilage matrix breakdown, providing a degree of chondroprotection alongside the mechanical benefits.
At our Reading clinic, we use clinically validated HA preparations selected on the basis of your specific joint condition severity and any previous injection history. Our preferred first-line options are Sinovial and Sinogel due to their fast-acting profile, strong tolerability data, and dual-component formulation advantages. Where a patient has previously responded well to an alternative preparation, we continue with that product to maintain consistent benefit.
Hyaluronic Acid Injections: Clinical Evidence and Patient Selection
Treatment Benefits
The clinical evidence base for hyaluronic acid injection in osteoarthritis is substantial. A 2023 study of 166 patients receiving a single high-concentration HA injection demonstrated that the majority achieved at least a 50% improvement in pain, stiffness, and functional mobility sustained at six months. Across a broader body of literature, HA injection consistently reduces pain visual analogue scale scores, improves WOMAC functional outcomes, and delays the requirement for surgical intervention in appropriately selected patients.
Beyond pain reduction, HA injection has been shown to reduce concentrations of matrix metalloproteinases and other catabolic enzymes within the joint that drive cartilage degradation. This positions HA not merely as a symptomatic treatment but as a therapy with meaningful disease-modifying properties in the articular environment.
Who Benefits Most
Hyaluronic acid injection is most effective for patients with mild to moderate osteoarthritis who have not achieved adequate relief from physiotherapy, activity modification, or oral analgesia. It is particularly appropriate for patients who wish to remain physically active, those for whom long-term non-steroidal anti-inflammatory use is medically inadvisable, and those who have had a steroid injection with limited or short-lived benefit.
Patients who have previously responded well to HA injection are excellent candidates for repeat treatment. Repeat injection is both safe and clinically appropriate, and outcomes in patients with a documented prior response are reliably strong.
Treatment Timeline
Most patients notice the beginning of improvement within 4 to 6 weeks of injection. Full benefit is typically achieved by 8 weeks. Clinical relief commonly persists for 6 months, with a meaningful proportion of patients maintaining benefit for up to 12 months. Treatment can be repeated safely when symptoms return.
Safety Profile
Hyaluronic acid injections are well tolerated across all patient populations. The most commonly reported side effect is mild localised soreness or transient stiffness at the injection site, typically resolving within 48 hours. Systemic reactions are rare. The safety record of HA injection across large-scale clinical studies is consistently strong.
Arthrosamid: A Different Category of Treatment
Arthrosamid® occupies a fundamentally different position in the injectable treatment landscape to hyaluronic acid. Where HA replaces a depleted biological component of synovial fluid, Arthrosamid structurally modifies the synovial membrane itself. Understanding this distinction is essential to appreciating why Arthrosamid is appropriate for some patients and not others, and why it produces the duration of benefit that it does.
Mechanism of Action
Arthrosamid® is a 2.5% polyacrylamide hydrogel. When injected into the knee joint under ultrasound guidance, it does not remain free within the joint space. Instead, it integrates into the synovial membrane, physically thickening and reinforcing the tissue. This creates a stable biological scaffold within the membrane that cushions the joint surfaces, reduces subchondral bone stress, and suppresses the inflammatory signalling that drives osteoarthritic pain at the synovial level.
Because Arthrosamid is non-biodegradable, this scaffold persists indefinitely within the tissue. Unlike hyaluronic acid, which is gradually metabolised and requires repeat administration, Arthrosamid is designed as a one-time structural intervention. A single treatment of six 1ml syringes administered under local anaesthetic delivers the complete therapeutic dose. No surgery is required. No hospital admission is necessary. The procedure is completed in a single outpatient appointment.
Clinical Effectiveness
Patients typically begin experiencing pain reduction within 4 weeks of treatment. Clinical studies report success rates above 80%, with statistically significant improvements in both pain and physical function. The WOMAC and PGA outcome measures used in Arthrosamid trials demonstrate sustained, clinically meaningful improvement at 2 years, placing Arthrosamid among the most durable injectable treatments currently available for knee osteoarthritis.
The evidence base spans over 20 years of research with data from 463 patients, providing a level of long-term clinical certainty that newer injectable therapies cannot yet match.
Long-Term Durability
A single Arthrosamid treatment provides pain relief lasting 3 to 5 years in the majority of patients. Clinical observation suggests a proportion of patients continue to benefit for 5 to 8 years. This durability profile is qualitatively different from any other injectable currently available at our Reading clinic and makes Arthrosamid the most cost-effective option over a 5-year horizon when compared to repeat HA injections.
Choosing Between Arthrosamid and Hyaluronic Acid
The decision between Arthrosamid and hyaluronic acid injection is not a matter of one being superior to the other. Both are appropriate treatments for osteoarthritis. The distinction lies in which is most appropriate for a specific patient based on their clinical presentation, disease severity, functional goals, and treatment history.
Hyaluronic acid is well suited to patients with mild to moderate osteoarthritis who are seeking durable symptomatic relief with a well-established, frequently repeated treatment. It is appropriate across a wider range of joints including the knee, hip, shoulder, and ankle. For patients who have responded well to HA previously, repeat treatment is both reliable and clinically straightforward.
Arthrosamid is specifically indicated for knee osteoarthritis at a moderate severity level. It is most appropriate for patients who have not achieved lasting relief from HA or steroid injection, those who wish to avoid the frequency of repeat injections, those seeking a non-surgical alternative to knee replacement, and those for whom the long-term cost and inconvenience of repeated treatments has become a consideration. Arthrosamid is not a repeat treatment. It is a single structural intervention designed to provide long-term relief from one procedure.
At Core Body Clinic’s Reading clinic, the decision between these treatments is made at your clinical assessment. We review your diagnostic imaging, your symptom history, your response to previous treatments, and your functional and lifestyle goals before recommending a specific pathway. Where your diagnosis has already been confirmed by a GP or consultant, this process is typically completed within your first appointment.
The Diagnostic Assessment at Our Reading Clinic
Neither Arthrosamid nor hyaluronic acid injection is administered without prior clinical assessment at our Reading clinic. This is not a bureaucratic requirement. It is a clinical necessity.
The precise joint affected, the degree of cartilage loss, the extent of synovial inflammation, and the integrity of surrounding soft tissue structures all influence which injection is most appropriate, the precise anatomical target within the joint, and the expected response. These variables cannot be determined from a symptom description or a referral letter alone.
At The Atrium, our assessment includes a detailed clinical history, physical examination of the affected joint, and ultrasound imaging performed in-house at the same appointment. Ultrasound allows us to visualise the joint in real time, confirm the degree of synovial thickening or effusion, and guide the injection needle to the precise intra-articular target with accuracy that landmark-guided injection cannot replicate.
For patients with existing MRI or X-ray imaging, we review this alongside our ultrasound findings to build the most complete clinical picture before treatment begins. Where Arthrosamid is being considered, this assessment also confirms the grade of osteoarthritis and rules out contraindications before the treatment is selected.
Arthrosamid and Hyaluronic Acid Injections at Our Reading Clinic
Arthrosamid and Hyaluronic Acid Injections at Our Reading Clinic
Core Body Clinic’s Reading clinic at The Atrium, Scours Lane, RG30 6AY is fully equipped to administer both Arthrosamid and hyaluronic acid injections under ultrasound guidance by advanced practice physiotherapists. All patients are assessed before treatment. We accept all major private medical insurance providers and welcome self-funding patients. Full pricing is available on our price list page.
No GP referral is required. Book your clinical assessment online or call 01792 369535.
What is the main difference between Arthrosamid and hyaluronic acid injection?
Hyaluronic acid replaces the naturally occurring lubricating fluid within the joint, reducing friction and inflammation. It is biodegradable and requires repeat administration every 6 to 12 months. Arthrosamid physically integrates into the synovial membrane, forming a permanent structural scaffold that cushions the joint and suppresses inflammation from within the tissue. A single Arthrosamid treatment provides relief lasting 3 to 5 years. The two treatments work through different mechanisms and suit different patient profiles, which is why we always assess before recommending either.
How quickly will I notice improvement after injection?
Hyaluronic acid typically produces noticeable improvement within 4 to 6 weeks, with full benefit reached by 8 weeks. Arthrosamid produces pain reduction within 4 weeks in most patients, with functional improvement continuing to develop over the following months. Neither treatment produces immediate same-day relief, and patients are counselled on realistic timelines at their assessment appointment.
Can I have both Arthrosamid and hyaluronic acid injected?
These treatments are not typically combined, as they target the same joint environment through different mechanisms. Your clinician will recommend one based on your diagnosis, severity, and treatment history. In some clinical situations, a patient may transition from HA to Arthrosamid when HA no longer provides adequate durability. Your clinician will discuss this at assessment.
Is Arthrosamid available on the NHS?
Arthrosamid is not currently routinely available on the NHS. It is available at Core Body Clinic’s Reading clinic as a private treatment. While the upfront cost is higher than that of hyaluronic acid injection, the long-term cost over a 5-year period is typically lower when the frequency of repeat HA treatments is taken into account.
Do I need a GP referral to access these injections in Reading?
No referral is required. You can self-refer by booking your assessment online or calling 01792 369535. We accept patients referred by GPs, consultants, and other healthcare professionals, and we are recognised by all major private medical insurance providers. Self-funding patients are welcome.