Sarcopenia, paraspinal muscle degeneration, and bone quality as prognostic factors for adjacent segment degeneration or disease after lumbar fusion: a systematic review and meta-analysis
摘要
Adjacent segment degeneration and disease are important long-term complications after lumbar fusion. Although traditional demographic, surgical, and radiographic risk factors have been widely studied, the role of patient-specific muscle-bone quality remains unclear. This systematic review and meta-analysis evaluated whether sarcopenia, psoas-related indices, posterior paraspinal muscle degeneration, and reduced bone quality are associated with radiographic adjacent segment degeneration (ASDeg), symptomatic adjacent segment disease (ASDisease), or ASDisease requiring revision surgery after lumbar fusion.
MethodsClinical studies assessing muscle-bone quality factors in adults undergoing lumbar fusion were systematically reviewed and quantitatively synthesized. Exposures included sarcopenia, psoas-related morphometric indices, multifidus or erector spinae fatty infiltration, posterior paraspinal muscle quantity, bone mineral density, CT-based Hounsfield units (HU), vertebral bone quality score, and endplate bone quality score. Endpoints were classified as radiographic ASDeg, symptomatic ASDisease, or surgical ASDisease before synthesis. Random-effects meta-analyses were performed using harmonized odds ratios or standardized mean differences. Risk of bias was assessed using QUIPS.
ResultsFifteen studies were included. Sarcopenia was associated with early ASDisease in two studies from the same research group, but the magnitude of association should be interpreted cautiously. Patients with ASDeg/ASDisease endpoints had worse psoas-related muscle quantity (SMD = 1.14), greater posterior paraspinal or multifidus fatty infiltration (SMD = 0.49), lower posterior paraspinal or multifidus muscle quantity (SMD = 0.48), and worse BMD/HU-based bone quality (SMD = 0.64). CT-HU showed a stable association (SMD = 0.35; I2 = 0%).
ConclusionsImpaired muscle-bone quality, particularly posterior paraspinal muscle degeneration and low CT-HU, appears to be associated with ASDeg/ASDisease endpoints after lumbar fusion. Evidence varies across markers and endpoint definitions, and prospective validation with standardized ASDeg and ASDisease phenotypes is needed.