Background: Greater than 50% of patients report significant pain with intraarticular injection of hyaluronate. The reciprocating procedure device (RPD), also known the reciprocating syringe, has 2 plungers that reciprocate with each other, permitting one-handed operation. The RPD increases physician control of the needle and is proposed to reduce patient pain during syringe procedures.
Objectives: To determine in a randomized controlled trial whether the RPD induces less pain than the traditional syringe during intraarticular hyaluronate therapy for the knee.
Methods: Eighty intraarticular injection procedures of the knee were randomized to either the conventional syringe or the RPD using hyaluronate sodium derivative (Hylan G-F-20). Outcome measures included physician's estimate of pain, patient pain (Visual Analogue Pain Scale [VAPS]), procedure duration, operator satisfaction, complications, and response to the injected medication.
Results: Patients reported 85% more pain than physicians estimated. Fifty-one percent (19/37) of subjects experienced moderate to severe pain with the conventional syringe, while only 14% (6/43) experienced pain with the RPD. The RPD reduced pain scores (RPD VAPS score: 2.12 +/- 2.15; conventional syringe VAPS score: 4.22 +/- 3.25; P < 0.001), reduced procedure time (RPD: 1.34 +/- 1.09, conventional syringe: 1.90 +/- 1.35 minutes, P < 0.001), and improved physician satisfaction (RPD VASS Score: 9.02 +/- 0.80, conventional syringe 5.69 +/- 1.33, P < 0.001).
Conclusions: Patients have considerably more pain with intraarticular needle introduction and injectable hyaluronate therapy than physicians estimate. The RPD reduces patient pain, reduces procedure time, and improves needle introduction compared with the conventional syringe for hyaluronate injection therapy for the knee.