What question did this study set out to answer?

This research investigates whether synovial hypertrophy and effusion assessed by ultrasound can predict outcomes after genicular nerve ablation for knee osteoarthritis.

February 12, 2026

Predictive Value of Synovial Hypertrophy and Synovial Effusion on Ultrasound for Clinical Outcomes of Genicular Nerve Ablation in Knee Osteoarthritis

Key Points

This research investigates whether synovial hypertrophy and effusion assessed by ultrasound can predict outcomes after genicular nerve ablation for knee osteoarthritis.
Conducted an observational study with 24 patients diagnosed with chronic knee osteoarthritis.
Patients underwent ultrasound-guided genicular nerve ablation targeting specific genicular nerves.
Synovial effusion and hypertrophy were graded using established criteria and measured quantitatively.
Pain and function were assessed using the NRS and WOMAC at baseline and 4 weeks post-procedure.
Predictive factors were analyzed using Firth logistic regression.
Mean NRS improved significantly from 6.75 to 3.88 (P < 0.001).
Mean WOMAC scores improved from 38.5 to 15.7 (P < 0.001).
Patients with mild or no synovial effusion had a greater WOMAC score reduction (33 points) compared to those with moderate/severe effusion (18 points).
Mild/no synovial hypertrophy also resulted in larger WOMAC reductions (28 points) versus those with severe hypertrophy (19 points).
Synovial hypertrophy was identified as a significant predictor of a positive response (adjusted OR = 8.75; P = 0.007).

Abstract

Abstract Background: Genicular nerve ablation (GNA) is an effective minimally invasive intervention for pain relief in knee osteoarthritis (OA). However, the predictive role of pre-procedural ultrasound findings, particularly synovial effusion (SE) and hypertrophy, remains underexplored. This study aimed to evaluate whether these sonographic parameters predict short-term outcomes following GNA. Materials and Methods: This observational study included 24 patients with chronic knee OA who underwent ultrasound-guided GNA targeting the superior medial, superior lateral, and inferior medial genicular nerves. SE and hypertrophy were graded according to Outcome Measures in Rheumatology and quantitative effusion thickness. Pain and function were assessed using the Numeric Rating Scale (NRS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline and 4 weeks post-procedure. Patients achieving ≥50% NRS reduction were defined as responders. Predictive factors were analyzed using Firth logistic regression. Results: Mean NRS improved from 6.75 ± 0.99 to 3.88 ± 1.83 ( P < 0.001), and mean WOMAC improved from 38.5 ± 3.9 to 15.7 ± 13.7 ( P < 0.001). Patients with mild or no SE showed greater improvement (WOMAC reduction = 33 points) than those with moderate/severe effusion (18 points). Similarly, mild/no hypertrophy showed a larger WOMAC decrease (28 vs 19 points). Firth logistic regression identified synovial hypertrophy (SH) as an independent predictor of response (adjusted odds ratios (OR) = 8.75; 95% confidence intervals 1.86–41.10; P = 0.007), whereas effusion showed a nonsignificant trend (OR = 0.67; P = 0.47). Conclusion: GNA provides significant short-term improvement in pain and function in knee OA. Ultrasound assessment of the synovial morphology enhances prognostication—patients with minimal SH and effusion demonstrate the greatest likelihood of favourable outcomes. Incorporating pre-procedural ultrasound phenotyping into routine evaluation may optimize patient selection and clinical success of GNA.

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Cite This Study

Ponnanna et al. (Mon,) studied this question.

synapsesocial.com/papers/698d6efe5be6419ac0d54ffb https://doi.org/https://doi.org/10.4103/jmupm.jmupm_17_25

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