Reviewer’s comment concerning “Technical factors related to the incidence of adjacent superior segment facet joint violation after transpedicular instrumentation in the lumbar spine” (Zhao Jie et al., MS-No. ESJO-D-08-00308)

This is a prospective study to analyze the incidence of superior segment facet joint violation after pedicel screw instrumentation in the lumbar spine and to evaluate technical factors related to the incidence. The study is well designed with clinical evidence.

Unfortunately it only repeats widespread clinical knowledge using sophisticated investigation tools as special CT scanning.

It is a known fact that pedicle screw insertion should not interfere with the integrity of adjacent (upper level) facets. Unfortunately this is not always possible especially in the advent of severe arthritic changes.

It is also a well known fact that the Weinstein or Magerl technique of pedicle screw application results in a less amount of facet joint violation compared to Roy Camille’s. The authors repeat this using an indirect tool (CT scan) to once again prove what is known. The information, which was gained by sophisticated tools could have been reported by the surgeon easily.

I would have appreciated if the authors had taken their patient group and looked for degeneration in an adjacent segment violated by a pedicle screw. This could be compared to a nonviolated group to find out about the influence of facet joint irritation on the history of osteoarthritis. Using the exact CT scanning method the authors have set up an even more valuable scientific result could have been achieved. Maybe this can be done in further analysis of the material.