Asian Spine J.  2015 Feb;9(1):65-74. 10.4184/asj.2015.9.1.65.

Surgical Correction in Patients with Lumbar Degenerative Kyphosis Who Had Low Bone Mineral Density: An Analysis of 40 Patients with a Minimum Follow-Up of Two Years

• Kim KT
• Chan CY
• Lee SH
• Huh DS
• Son ES

• KMID: 2270195
• DOI: http://doi.org/10.4184/asj.2015.9.1.65

Abstract

STUDY DESIGN: Retrospective study. PURPOSE: To investigate influence of bone mineral density (BMD) on the surgical correction of lumbar degenerative kyphosis (LDK). OVERVIEW OF LITERATURE: No studies so far have reported the influence of BMD on the surgical correction of LDK.
METHODS
Forty LDK patients with more than 2 years follow-up were studied. Pelvic incidence (PI), pelvic tilt, sacral slope, sagittal vertical axis (SVA), lumbar lordosis (LL), and thoracic kyphosis were measured preoperatively, immediate postoperatively and at final follow-up. Adverse outcomes: proximal adjacent fractures, sagittal decompensation, pseudoarthrosis, and cage subsidence were documented.
RESULTS
There were 37 females and 3 males. Average age was 65.1+/-4.5 years and mean follow-up was 34.2+/-16.7 months. 42.5% were Takemitsu type 3 curves, 27.5% type 2, 20.0% type 4 and 10.0% type 1. 37.5% had osteopenia, 40.0% osteoporosis and 22.5% had severe osteoporosis. SVA improved from 237.0+/-96.7 mm preoperatively to 45.3+/-41.8 mm postoperatively (p=0.000). LL improved from 10.5degrees+/-14.7degrees to -40.6degrees+/-10.9degrees postoperatively (p=0.000). At final follow-up SVA deteriorated to 89.8+/-72.2 mm and LL to 34.7degrees+/-15.8degrees (p=0.000). The association between late sagittal decompensation, pseudoarthrosis, or proximal adjacent fractures and osteoporosis was insignificant. The difference between immediate postoperative LL and PI (PIDiff) had a significant association with sagittal decompensation and pseudoarthrosis.
CONCLUSIONS
Osteoporosis did not influence the degree of correction, late sagittal decompensation, proximal adjacent fractures, and pseudoarthrosis in LDK. PIDiff had a significant association with sagittal decompensation and pseudoarthrosis.

Keyword

Lumbar degenerative kyphosis; Bone mineral density; Surgery; Outcome; Osteoporosis

MeSH Terms

Animals
Axis, Cervical Vertebra
Bone Density*
Bone Diseases, Metabolic
Female
Follow-Up Studies*
Humans
Incidence
Kyphosis*
Lordosis
Male
Osteoporosis
Pseudarthrosis
Retrospective Studies