[External fixator of the cervical spine--a new diagnostic tool].

Soft tissue injuries of the neck may cause severe long-standing pain. The clinical findings are sparse and the identification of the painful segments with conventional diagnostic tools is often impossible. Temporary segmental external fixation for a soft tissue injury of the cervical spine was performed as a diagnostic procedure in 24 patients. The instrumentation was applied according to the established techniques of the insertion of facet screws in the cervical spine. The segments to be instrumented were evaluated by clinical and radiological findings, such as local pain and increased mobility in the functional X-rays. However, none of these findings were convincing enough to proceed directly to fusion for pain relief. Evaluation of external fixation consisted of alternatively fixing different instrumented segments and having the patients rate their pain on a visual analogue pain scale. External fixation of the suspected segments resulted in marked pain relief, which was recorded subjectively by the visual analogue pain scale in 68% of the patients. The pain relief (8.2 points preoperatively--2.6 points postoperatively on average) could be permanently established by successful fusion of these segments in 17 patients. Four of the patients indicated no relief of pain at the follow-up (12.9 months postoperatively). No fusion was performed in 3 patients in whom the diagnostic procedure with external fixation allowed no conclusion about the painful segment. As it is an invasive procedure, external fixation of the cervical spine should be reserved for cases, in which conventional methods have failed to established a clear diagnosis of segmental instability and conservative therapy could not relieve the symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)