Purpose of study and background. Mechanical overloading initiates intervertebral disc degeneration, presumably because cells break down the extracellular matrix (ECM). We used Fourier Transform Infrared Spectroscopy (FTIR) imaging to identify, visualize and quantify the ECM and aimed to identify spectroscopic markers for early disc degeneration. Methods and Results. In seven goats, one disc was injected with chondroitinase ABC (mild degeneration) and after three months compared to control. Ex vivo, 50 caprine discs received physiological loading (50–150N) or overloading (50–400N) in a loaded disc culture system. To determine whether ECM degeneration is due to cell activity, half of the discs was subjected to freeze-thaw cycles. Spectroscopic images were collected at 1000–1300 cm. −1. and analyzed using multivariate curve resolution analysis. In vivo, less proteoglycan was found in the degenerated group (p<0.05), especially in the nucleus. Collagen content was increased in the nucleus and anterior annulus, and had higher entropy (p<0.01), indicating matrix disorganization. In the ex vivo experiment, the proteoglycan/collagen ratio was decreased (p<0.05) in the vital group and there was an increase in collagen entropy (p<0.05). A significant interaction between loading and vitality was found in the amount of collagen (p<0.05), but not in the entropy. Conclusion. Three weeks of mild overloading causes measurable changes in the extracellular matrix. Increased collagen entropy indicates that remodeling of collagen is a first step into disc degeneration. We could not confirm, however, that increase in entropy was due to cell activity. FTIR imaging allows more detailed investigation of early disc degeneration than traditional measures. There are no conflicts of interest. Partially funded by Dutch Arthritis Funds, personal grant KSE

Acute angulation at the thoracolumbar junction with segmental subluxation of the spine occurring at the level above an anteriorly hypoplastic vertebra in otherwise normal children is a rare condition described as infantile developmental thoracolumbar kyphosis. Three patient series with total of 18 children have been reported in the literature. We report five children who presented with thoracolumbar kyphosis and discuss the treatment algorithm. We reviewed the medical records and spinal imaging at initial clinical presentation and at minimum two-year follow-up. The mean age at presentation was eight months (two to 12). All five children had L2 anterior vertebral body hypoplasia. The kyphosis improved spontaneously in three children kept under monitoring. In contrast, the deformity was progressive in two patients who were treated with bracing. The kyphosis and segmental subluxation corrected at latest follow-up (mean age 52 months; 48 to 60) in all patients with near complete reconstitution of the anomalous vertebra. The deformity and radiological imaging on a young child can cause anxiety to both parents and treating physicians. Diagnostic workup and treatment algorithm in the management of infantile developmental thoracolumbar kyphosis is proposed. Observation is indicated for non-progressive kyphosis and bracing if there is evidence of kyphosis and segmental subluxation deterioration beyond walking age. Surgical stabilisation of the spine can be reserved for severe progressive deformities unresponsive to conservative treatment.

Cite this article: Bone Joint J 2015;97-B:982–7.