Injections

Corticosteroid (Steroid) Injections

• Knee Osteoarthritis (OA):
  • Guidelines: International guidelines consistently support short-term symptom relief from intra-articular corticosteroids when first-line care (exercise, education, weight management, NSAIDs) is insufficient. The 2019 OARSI guideline conditionally recommends steroid injections for knee OA; it emphasises exercise/education as foundational care.
  • Randomised trial signal of harm with frequent, long-term use: In a 2-year RCT of 140 patients receiving 40 mg triamcinolone every 3 months, steroids led to greater cartilage thickness loss versus saline (−0.21 mm vs −0.10 mm; between-group −0.11 mm; 95% CI −0.20 to −0.03) and no pain benefit. This supports limiting frequency and duration.
  • Practical take: Best for an inflamed, irritable knee needing a short-term flare settle (weeks), not as a repetitive long-term strategy.
• Hip & Shoulder:
  • Hip OA: OARSI allows consideration similar to knee OA in select patients; benefits are short-term and patient-specific.
  • Subacromial/Rotator Cuff–Related Pain: Earlier systematic reviews show modest, short-term pain relief compared with NSAIDs or placebo; effect wanes over weeks to a few months. Repeated injections risk tendon effects; use judiciously.

Hyaluronic Acid (HA, “Gel”) Injections

• Knee OA—mixed/negative overall effect at population level:
  • BMJ 2022 systematic review/meta-analysis of randomised trials found viscosupplementation yielded a small, clinically unimportant reduction in pain versus placebo and reported an increased risk of serious adverse events; authors concluded results do not support broad use.
  • AAOS Knee OA CPG (non-arthroplasty): Not recommended for routine use in symptomatic knee OA.
  • Practical take: Some individuals report benefit (especially milder OA phenotypes), but average effect is small; shared decision-making is key.
• Hip OA: Evidence is less robust than knee; comparative trials are limited. Some reviews compare PRP vs HA with variable findings; heterogeneity is high.

Platelet-Rich Plasma (PRP)

• Knee OA:
  • Network meta-analyses (2023–2025) generally show PRP (and some biologic protocols) achieving greater pain and function improvement at 6–12 months than corticosteroids and, in many analyses, than HA; durability beyond 12 months varies and protocols differ (single vs series, leucocyte-poor vs rich).
  • Guideline posture: Major public guidelines (ACR/OARSI/AAOS) have been cautious historically due to heterogeneity and cost; they prioritise core treatments first and consider PRP on a case-by-case basis.
  • Practical take: PRP can be a reasonable option for mild–moderate knee OA seeking longer relief than steroids, understanding out-of-pocket costs and variability in preparation.
• Hip OA: Early comparative evidence suggests PRP may perform as well as or better than HA for symptoms in some studies, but trials are smaller and heterogeneous.

Genicular Nerve Procedures (Diagnostic Blocks & Radiofrequency)

• For chronic knee OA pain not yet proceeding to arthroplasty:
  • Randomised data suggest cooled radiofrequency ablation (RFA) of genicular nerves improves pain/function compared with intra-articular HA in selected patients; real-world and sham-controlled trials support benefit at up to 6–12 months in appropriate candidates.
  • Ongoing trials continue to refine indications and technique (e.g., phenol neurolysis vs RFA vs conservative care).

Bursitis & Tendinopathy (Shoulder, Hip)

• Subacromial pain/rotator cuff–related shoulder pain: Systematic reviews indicate small, short-term benefits from subacromial steroid injections; benefits diminish by months. Consider as part of a plan anchored in rehab.
• Greater Trochanteric Pain Syndrome (GTPS): Evidence supports short-term pain relief from corticosteroid injections; comparisons with PRP, physio, or shockwave therapy show variable results across small RCTs; ultrasound guidance can improve accuracy.

How Often, and Safety Considerations

• Frequency: Given the 2-year RCT signal of accelerated cartilage loss with quarterly knee steroid injections, we avoid frequent, repeated steroid use; we individualise intervals and aim for the fewest injections necessary.
• Diabetes: Steroids can transiently raise blood glucose; we advise monitoring and coordination with your GP for insulin/oral agent adjustments.
• Hyaluronic Acid: Population-level benefit is small; not routinely recommended by AAOS for knee OA, and 2022 BMJ meta-analysis questions broad use. Consider selectively after shared decision-making.
• PRP: Autologous product with low adverse-event rates in trials; outcomes vary with preparation (e.g., leucocyte-poor vs rich), dose, and number of injections. We use standardised, evidence-aligned protocols to reduce variability.
• Procedure guidance: Ultrasound or fluoroscopic guidance improves accuracy (hip, shoulder, GTPS, deep joints), which can enhance outcomes and reduce complications.

How We Choose the Right Injection

We base recommendations on your diagnosis, OA severity, signs of active inflammation, comorbidities, and your goals. In general:

• Need rapid flare control: Consider single, judicious corticosteroid injection while advancing rehab.
• Seeking longer relief (mild–moderate knee OA): Discuss PRP after core care; set realistic expectations (6–12 months typical in trials).
• Considering HA: We discuss modest average effect and guideline positions; may trial in selected patients who prefer it and understand uncertainties.
• Persistent knee pain not ready for replacement: Consider genicular nerve RFA after diagnostic blocks if appropriate.