Relation Between Adjacent Superior Segmental Disease and Facet Joint Violations After Posterolateral Lumbar Fusion

ABSTRACT

STUDY DESIGN: To analyze the relationship between the adjacent superior segment disease and facet joint violations after lumbar fusion. OBJECTIVES: We retrospectively analyzed the relationship between the adjacent superior segment disease and facet joint violations after lumbar fusion. SUMMARY OF LITERATURE REVIEW Among numerous literatures regarding adjacent superior segment disease, there is no analysis concerning the relationship between adjacent superior segment disease and facet joint violations after lumbar fusion. MATERIALS AND METHODS: We reviewed 2056 patients who underwent lumbar fusion, between March 2004 and April 2009. Analysis was performed for 79 (3.8%) of the 2056 patients with adjacent superior segment disease and needed a second operation. A facet joint was considered as 3 types of violations with computed tomography scans if any of the following situations were encountered pedicle screw clearly within the facet joint; pedicle screw head clearly within the facet joint; and pedicle screw and/or screw head within 1mm from or abutting the facet joint, without clear joint involvement. RESULTS: The incidence of the violations was 45% (36/79) of all patients and 28% (44/158) of all screws. The incidence of L4-5 facet joint violations was 35% (28/79) of patients with adjacent superior segment disease, statistically. CONCLUSIONS: Facet joint violations were observed in patients with the adjacent superior segment disease after posterolateral lumbar fusion. Because L3-4 facet joint violations increased when L4-5 fusion was done, more care should be taken to avoid facet joint violations when the surgeon is considered for insertion of the pedicle screws at L4-5.