Patients with Lumbar Degenerative Kyphosis and Kyphoscoliosis (LDK) complain of stooped gait, persistent low back pain and weakness. Because operative treatment of LDK imposes considerable operative intervention for aged patients, an indication should be strictly limited; those have severe low back pain with lumbar kyphosis which afflicts upright walking disturbing house keeping, patients aged less than 70 as a rule and have no critical general complication as well. Purpose of this paper is to compare factors that affect the results of operative treatment of LDK. 19 patients were reviewed retrospectively in these series (av. aged 62.7, all female except one), who were followed-up for 3.0 years in average (14 months-8 years.) after the last surgery. Number of fused vertebra comprised 3 in 4 cases, 4 in 5, 5 in 3, 6 in 2, 7 in 2, 8 in 1, 9 in 2 respectively. In these cases 8 (av. aged 60.4) had no interbody fusion at all, one segment in one, 2 segments in 4, and 3 and more in 6 either anterior or posteriorly. Results were evaluated as excellent, good, fair and poor based on a correction rates of C7 plumb line and T1 tilt angle, as well as correction of lumbar kyphosis angle. The result was evaluated as excellent in 2 cases, good in 6, fair in 6 poor in 5. No co-relation was found between the results and number of fused vertebra at the last stage. However, patients whose operation include interbody fusion (IBF) of 3 and more contiguous segments showed either excellent or good, but all cases with single segment or no IBF groop showed either poor or fair, where those with 2 segments had good in 2 cases and fair in 2 respectively. There were relatively many poor results due to instrument failures (6 cases), insufficient correction of the deformity, compression fracture and increase of kyphosis above and below IBF level, possibly caused by progression of osteoporosis and degeneration. Four patients were found nerve root symptom after surgery, but almost healed by revision in several weeks. In order to obtain good result correction should include interbody fusion of at least 3 contiguous lumbar segments for multilevel anterior support and rigid instrumentation in sufficient length. Accurate planning before operation and careful surgical procedure should be emphasized to avoid nerve entrapment and instrument failure.
