Effectiveness of Injection Strategies on Patients With Patellar Tendonitis (Jumpers' Knee): A Network Meta-analysis of Randomized Controlled Trials.

Context: Patellar tendonitis (PT) is a common degenerative disease of the patellar tendon that seriously affects the sports careers of elite athletes and activities of daily living of sports enthusiasts. Injection therapy is a prevalent invasive treatment for PT.

Objective: This work comprehensively analyzes various injection treatments for PT that consider agent type and characteristics, frequency, and assessment timepoints by meta-analysis.

Data sources: PubMed, Embase, and the Cochrane Library were sources of data.

Data selection: Randomized controlled trials (RCTs) analyzing the effect of various injection strategies on the treatment of patients with PT were considered.

Study design: Systematic review and meta-analysis.

Level of evidence: Level 2.

Data extraction: First author, year of publication, research location, registration information, patient type, sample size, age, sex, intervention, control treatment, and follow-up period in each study were extracted.

Results: Nineteen RCTs were included in the analysis. In the network meta-analysis of Victorian Institute of Sports Assessment-Patellar (VISA-P) outcomes, polidocanol (standardized mean difference (SMD), 6.52; 95% CI 4.75, 8.30; P < 0.01), tenocyte-like cells (SMD, 4.08; 95% CI 2.92, 5.25; P < 0.01), and leukocyte-poor platelet-rich plasma (LP-PRP) plus high-volume image-guided injection (HVIGI) (SMD, 1.56; 95% CI 0.62, 2.50; P < 0.01) were significantly superior to noninjection conservative treatment, mainly at the 6-month follow-up timepoint. For visual analog scale results, multiple dry needling (DN) (SMD, -1.78; 95% CI -2.56, -1.00; P < 0.01), LP-PRP (SMD, -0.71; 95% CI -1.31, -0.12; P = 0.02), and LP-PRP plus HVIGI (SMD, -1.31; 95% CI -2.22, -0.39; P < 0.01) were significantly superior to blank, which was also mainly at the 6-month timepoint.

Conclusion: Injection-related treatments: polidocanol, tenocyte-like cells, LP-PRP, and multiple DN showed potential short (1-3 months) or medium (6 months)-term treatment benefits. There is still no evidence for injection interventions with long-term therapeutic benefit.