Twenty-three studies were included in the review (n=679, range 10 to 66). Six studies were RCTs with high overall methodological quality (median PEDro score of 7.5, range 6 to 9). Allocation concealment was applied in four studies. Subject blinding was used in six studies. No studies undertook intention-to-treat analysis.
Injection-based interventions: Two RCTs of excellent quality found that botulinum A was not superior to placebo for reducing pain intensity at three or six months post treatment. For patients with chronic whiplash-associated disorder, corticosteroid intra-articular and selective nerve root block injections did not appear to be effective for pain relief (four studies; one RCT). Single case series for tropisetron trigger point injections, dextrose and lidocaine-articular injections and epidural blood patch therapy did not provide strong enough evidence to suggest that any of these interventions was effective for treatment of chronic whiplash-associated disorder.
Surgical interventions: There was some evidence (one RCT, two follow-up studies and five non-RCTs) that radiofrequency neurotomy iwas s effective in reducing pain in patients with chronic whiplash-associated disorder and that the procedure was repeatable, although pain relief may not be permanent. There was very limited evidence that occipital nerve decompression (one case series) and carpal tunnel decompression (one case series) were effective in reducing whiplash-related pain or headache. It was unclear whether cervical discectomy and fusion (two low-quality case series) offered relief for chronic whiplash-associated disorder patients.