Ajithkumar Puthentheruvil Anantharaman outlines how an MDT containing a senior dietetic first contact practitioner is helping patients with knee osteoarthritis.
In primary care, musculoskeletal (MSK) clinicians and dietitians1 frequently encounter patients trapped in a debilitating ‘pain–weight cycle’.
Knee osteoarthritis (OA) is no longer viewed simply as a ‘wear and tear’ disease of the aged2 – it is now understood as a complex, low-grade inflammatory condition driven by a combination of biomechanical overload and metabolic dysregulation.
For the patient, the symptoms are physical, but the consequences are lifestyle-ending. Pain prevents physical activity, which leads to weight gain, which then increases the mechanical load3 on the tibiofemoral and patellofemoral joints.
This increased load further damages the articular cartilage, releasing pro-inflammatory cytokines into the synovial fluid, which triggers more pain.2 This case study evaluates how a strategic, interdisciplinary intervention utilising an intra-articular corticosteroid injection (IACSI) as a ‘facilitator’ for dietetic-led weight management can successfully disrupt this cycle.2,3
Case presentation and clinical crossroads
The patient was a 59-year-old woman with moderate knee OA (Kellgren-Lawrence grade 2–3).4 She presented with classic markers of the condition: activity-related pain, morning stiffness lasting approximately 20 minutes and ‘giving way’ of the knee under load.5 Crucially, she was already engaged with our primary care network (PCN) dietitian.
She understood the necessity of weight loss to reduce the load on her joints,3,5 but she had reached a clinical crossroads.
Despite her dietary compliance, she could not engage in the exercise portion of her rehabilitation because the pain was too severe.6
At this point, continuing with conservative management alone, analgesia and diet was likely to lead to failure.7 We needed a ‘circuit breaker’.
The pathophysiological rationale for injection
In OA, the joint environment is characterised by an excess of pro-inflammatory mediators such as interleukin-1 (IL-1) and tumour necrosis factor-alpha (TNF-a).2,3 These mediators lead to synovitis (inflammation of the joint lining), which is often the primary driver of the sharp pain patients feel during an exacerbation.
An intra-articular corticosteroid injection aims to reset this environment. By introducing a potent anti-inflammatory agent directly into the synovial space,2,8 we can achieve:
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Reduction in synovial permeability: Reducing the effusion or swelling that causes joint tension
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Gene transcription modulation: Corticosteroids bind to intracellular receptors to suppress the production of COX-2 and other inflammatory proteins
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Mechanical relief: By reducing the inflammation, we reduce the sensitivity of the nociceptors (pain receptors) within the joint capsule9
The interdisciplinary ‘safety gate’: The 56mmol/mol rule
One of the most significant risks associated with corticosteroid injections is their effect on systemic glucose metabolism.3,9 Even a localised injection can lead to transient hyperglycaemia as the steroid is absorbed into the systemic circulation. For a patient working with a dietitian, this metabolic spike can be disruptive.
To manage this, we implemented a strict ‘safety gate’ protocol:
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The threshold: IACSI is safely performed if the patient’s most recent HbA1c is below 56mmol/mol7,8,9
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The logic: Patients with an HbA1c above this level are at a higher risk of prolonged or dangerous hyperglycaemia following the injection. By setting this limit, we ensure that the ‘therapeutic window’ for the knee does not come at the cost of a metabolic crisis
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Collaboration: This rule allowed the first contact practitioner (FCP) to refer the patient back to the dietitian for ‘optimisation’ before the procedure. It turned the injection into a goal for the patient to work towards by managing their sugars through diet first
The dietetic intervention: managing the ‘steroid spike’
Once the patient met the 56mmol/mol threshold, the dietitian implemented a specific ‘sick day’ nutritional strategy for the 48–72 hours following the injection.3,9 This included:
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Low-glycaemic index (GI) focus: Reducing refined carbohydrates and replacing them with high-fibre alternatives to slow glucose absorption
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Anti-inflammatory loading: Increasing intake of omega-3 fatty acids (via oily fish or walnuts) to synergetically support the anti-inflammatory action of the methylprednisolone
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Hydration: Ensuring high water intake to support renal clearance and mitigate the bloating often felt post-steroid
Pharmacological and procedural execution
The procedure involved a landmark-guided injection of 40mg methylprednisolone acetate mixed with 1% lidocaine.5,7,8
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The role of lidocaine: Beyond procedural comfort, lidocaine serves a diagnostic purpose. If the patient feels 100% relief in the 15 minutes following the injection, we have confirmed that the pain is indeed originating from within the joint, rather than being referred from the hip or lumbar spine
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The role of methylprednisolone: As a depot corticosteroid, it stays within the joint for several weeks,8 providing a sustained anti-inflammatory ‘blanket’ that allows the patient to begin movement without the usual flare-up.
Outcomes: the ‘therapeutic window’ in action
The results were transformative. Within 72 hours, the patient’s pain scores dropped from an 8/10 to a 2/10. However, the most important outcome was not the pain relief – it was the functional opportunity.
With the pain barrier removed, the patient was able to progress to a more aggressive physical activity plan. The patient moved from sedentary behaviour to a 30-minute daily brisk walk. This increased energy expenditure, combined with the dietitian’s calorie-controlled plan,3 resulted in a 5% total body weight loss over the following 12 weeks. This weight loss reduced the mechanical pressure on her knee by nearly 20kg per step (based on a 1:4 load-to-weight ratio in the knee joint),6 effectively providing a long-term ‘mechanical injection’ that lasted far longer than the steroid itself.
Safety-netting and worst-case contingencies
No invasive procedure is without risk, and for a senior FCP, safety-netting is a regulatory requirement. The patient was provided with a ‘Red Flag’ card with three specific pathways:1,5
1. Suspected septic arthritis: If the joint became red, hot or excessively swollen, or if she developed a fever, she was instructed to attend A&E immediately for joint aspiration to rule out infection
2. Glycaemic crisis: If blood glucose monitors showed readings above 15mmol/L for more than 48 hours, she was to contact the PCN diabetic lead nurse
3. Non-response: If the injection provided no relief after 14 days, a referral for an MRI or an orthopaedic consultation was the next step to investigate structural damage that steroids cannot fix (such as a significant meniscal tear)
Regulatory and professional governance
This intervention was governed by the Health Education England (HEE) Roadmap to Practice and the Medicines Act 1968. For an FCP, administering a prescription-only medicine (POM) via a Patient-Specific Direction (PSD) requires rigorous documentation of batch numbers, expiry dates and informed consent. This ensures that the patient is protected and that the clinician is operating within their professional scope of practice.
Conclusion: the future of integrated primary care
This case study demonstrates that the most effective primary care does not happen in silos. If the physiotherapist only injected the knee, the relief would have been temporary. If the dietitian only managed the diet, the progress would have been blocked by pain. By working together – and using the 56mmol/mol HbA1c threshold as a shared safety tool – we provided a holistic solution.
For advanced practitioners, the lesson is clear: our value lies not just in the interventions we perform, but in how we integrate those interventions into the patient’s wider health journey. Success is not measured by a pain-free joint in week one, but by a healthier, more active patient in year one.
References
- Health Education England (2021). First Contact Practitioners and Advanced Practitioners in Primary Care (MSK): A Roadmap to Practice.
- Primorac, D., et al. (2020). Knee Osteoarthritis: A Review of Pathogenesis and State-Of-The-Art Non-Operative Therapeutic Considerations. Genes. https://doi.org/10.3390/genes11080854
- Sophocleous A. The Role of Nutrition in Osteoarthritis Development. Nutrients. 2023 Oct 12;15(20):4336. doi: 10.3390/nu15204336. PMID: 37892417; PMCID:PMC10609695.
- Sheinkop, M., Langhenry, M., Abd-Elsayed, A. (2024). Life, 14(10), 1340. https://doi.org/10.3390/life14101340 Holland, K. (2023, June 13).
- NICE (2022). Osteoarthritis in over 16s: diagnosis and management (NG226).
- Adouni M, Aydelik H, Faisal TR, Hajji R. The effect of body weight on the knee joint biomechanics based on subject-specific finite element-musculoskeletal approach. Sci Rep. 2024 Jun 14;14(1):13777. doi: 10.1038/s41598-024-63745-x. PMID: 38877075; PMCID: PMC11178890.
- Bensa, A., et al. (2024). Intra-articular corticosteroid injections in knee osteoarthritis: A systematic review. KSSTA Journal. https://doi.org/10.1002/ksa.12057
- McAlindon, T. E., et al. (2017). Effect of Intra-articular Triamcinolone vs Saline on Knee Cartilage Volume.JAMA. https://doi.org/10.1001/jama.2017.5283
- Sytsma TT, Greenlund LS, Fischer KM, McCoy RG. Impact of Intra-Articular Corticosteroid Injection on Glycemic Control: A Population-Based Cohort Study. Clin Diabetes. 2024 Winter;42(1):96-103. doi: 10.2337/cd22-0124. Epub 2023 Aug 25. PMID: 38230338; PMCID: PMC10788672.
