Effects of long-term immobilisation on cortical bone mass after traumatic amputation of the phalanges estimated by digital X-ray radiogrammetry.
Osteopenia of the cortical and trabecular bone partition is a common finding after immobilisation. Digital X-ray radiogrammetry (DXR) seems to quantify cortical demineralisation caused by circular saw amputation already few days after accident.


BACKGROUND
The study analyses the extent of demineralisation caused by immobilisation in patients with digital amputation after a circular saw injury, and elucidates the period of time which discloses a significant deprivation of bone mineral density estimated at the metacarpalia II-IV using DXR.


METHODS
Twenty-eight patients with digital amputations underwent measurements of bone mineral density, cortical thickness, bone width and metacarpal index using DXR-technology in a follow-up up to 902 days.


RESULTS
The data showed a significant decline of bone mineral density (-10.47%), the metacarpal index (-4.38%), the bone width (-12.06%) and the cortical thickness (-7.04%) after trauma-related amputation. The cortical demineralisation of the metacarpals could already be revealed in two patients after the second day, according to the amputation of phalanges (-3.65%).


CONCLUSIONS
The inhibition of the periosteal bone formation detected by DXR-technique seems to be a specific finding caused by amputation, which thus differs from normal age-related (i.e., endosteal) bone loss and from demineralisation following acute immobilisation (i.e., trabecular osteopenia).
Schäfer
M-L
ML
Institute of Diagnostic and Interventional Radiology, Friedrich-Schiller-University Jena, Erlanger Allee 101, 07747, Jena, Germany.
Pfeil
A
A
Renz
D M
DM
Lehmann
G
G
Schmidt
M
M
Hansch
A
A
Hein
G
G
Wolf
G
G
Kaiser
W A
WA
Böttcher
J
J
D015502:Absorptiometry, Photon / Q000379:methods; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000673:Amputation, Traumatic / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D005383:Finger Injuries / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology; D050278:Finger Phalanges / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D007103:Immobilization / Q000502:physiology; D008137:Longitudinal Studies; D008875:Middle Aged; D055815:Young Adult