Persistent low-normal bone mineral density in adolescent idiopathic scoliosis with different curve severity:​ a longitudinal study from presentation to beyond skeletal maturity and peak bone mass

Li, Xue; Hung, Vivian Wing Yin; Yu, Fiona Wai Ping; Hung, Alec Lik Hang; Ng, Bobby Kin Wah; Cheng, Jack Chun Yiu; Lam, Tsz Ping; Yip, Benjamin Hon Kei

Affiliations

¹School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region

²Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong Special Administrative Region

³SH Ho Scoliosis Research Laboratory, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region

⁴Bone Quality and Health Centre, Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Hong Kong Special Administrative Region

⁵Joint Scoliosis Research Centre of the Chinese University of Hong Kong and Nanjing University, The Chinese University of Hong Kong, Hong Kong Special Administrative Region

Abstract and keywords

Objectives: Low bone mineral status has been reported in patients first presented with adolescent idiopathic scoliosis (AIS). We aimed to study whether low-normal bone mineral density (BMD) is persistent among AIS girls during puberty and at peak bone mass, and whether if such persistence is associated with curve severity and differed from healthy controls.

Method: This prospective longitudinal study comprised 550 AIS girls and 194 healthy control subjects followed from 1997 till 2016. Low-normal BMD was defined as z-standardized bone mineral density (z-BMD) of bilateral femoral neck ≤ −1. Markov Chain 2-stages analysis was conducted to investigate the low-normal BMD transition rate. Linear mixed-effects model and Bland-Altman plot were used to investigate whether low-normal BMD is persistent among a subgroup of AIS patients that reached peak bone mass.

Results: The average z-BMD were comparable between AIS cohort and controls at 11 years old (−0.532 vs −0.602), but at 19 years old z-BMD worsened among AIS subjects (−0.860) while controls z-BMD improved (−0.455). During growth period until skeletal maturity, persistence of low-normal BMD was high in both cohorts (>80%) and the AIS group with severe curve presented 100% persistence. Subgroup analysis revealed that z-BMD of AIS patients at skeletal maturity and peak bone mass were highly correlated (r² = 0.905) and with good agreement.

Conclusion: AIS patients had poorer BMD that is associated with curve severity and more likely to persist beyond peripubertal period and at peak bone mass when compared to controls.

Keywords: Adolescent idiopathic scoliosis; Bone mineral density; Low-normal BMD; Low bone mass

Links

DOI: 10.1016/j.bone.2019.115217

PubMed: 31891787

WoS: 000517355400005

History

Received: 2019-08-16

Revised: 2019-12-26

Accepted: 2019-12-26

Online: 2019-12-28

Cited Works (1)

Year	Entry
2001	NIH Consensus Development Panel on Osteoporosis Prevention, Diagnosis, and Therapy. Osteoporosis prevention, diagnosis, and therapy. JAMA. February 14, 2001;285(6):785-795.