TABLE 2.

Summary of studies evaluating sterile water trigger point injections for chronic whiplash-associated disorder

Reference, year, country, score	Population and methods	Outcome measures	Results
Byrn et al (12), 1993, Sweden, PEDro score = 6	Randomized contolled trial. 40 patients with whiplash-induced neck pain and impaired cervical range of motion of 4–6 years that was refractory to analgesics and physiotherapy were randomly assigned to receive 0.3–0.5 mL subcutaneous injections of either sterile water or saline in each tender trigger point (range 5–80 injections per patient). Each patient received up to 3 treatments during the first 2 months of the protocol	Pain intensity (VAS), mobility of the cervical spine (Myrin goniometer), personality (the Neuroticism, Extroversion and Openness to experience [NEO] personality inventory) and psychological symptoms (Beck Depression Inventory, Spielberger Anxiety Test and Mood Adjective Checklist) were assessed immediately pre- and post-treatment, and at 1, 3 and 8 months after the first treatment	Patients in the sterile water group reported significantly less mean pain (0.8 versus 2.0, P<0.05) and greater cervical mobility (54° versus 23°, P<0.05) immediately postinjection than those in the saline group; these differences remained significant at the 8-month follow-up (2.4 versus 4.7, P<0.001; and 20° versus −11°, P<0.05, for pain and mobility, respectively). No between-group differences in personality or psychological symptoms were reported
Byrn et al (11), 1991, Sweden, no score	Case series. 10 patients with ≥6 months whiplash-related neck pain and impaired cervical range of motion were included following a failed course of analgesics and physiotherapy. All tender trigger points received a 0.1 mL intracutaneous injection of sterile water, and patients were encouraged to intensify their physiotherapy treatment. The procedure was repeated in patients whose pain recurred	Pain intensity (VAS) was assessed before the first injection and at unspecified intervals over the following 2 months	8 patients were pain free (VAS = 0) and 2 experienced minimal pain (VAS = 2) immediately following the first injection. Nine of the patients were pain free at the end of the follow-up period, 3 of them after a single treatment, while 6 required 2 to 4 treatments. Significance values were not reported

PEDro Physiotherapy Evidence Database; VAS Visual analogue scale