title: Assessment of loading history of compartments in the knee using bone SPECT/CT: a study combining alignment and 99mTc-HDP tracer uptake/distribution patterns.
abstract: This study investigates if the mechanical/anatomical alignment influences the intensity values as well as the distribution pattern of SPECT/CT tracer uptake. Eighty-five knees (mean age 48 ± 16) undergoing 99mTc-HDP-SPECT/CT due to pain were prospectively included. SPECT/CTs were analyzed using a previously validated localization method. The maximum intensities in each femoral, tibial, and patellar joint compartment (medial, lateral, central, superior, and inferior) were noted using a color-coded grading scale (0-10). The Kellgren-Lawrence osteoarthritis score (KL) was assessed on standardized radiographs. Long leg radiographs were used to assess the mechanical/anatomical leg alignment, which was classified as varus, valgus, or neutral. The alignment and KL was correlated with the intensity of tracer uptake in each area of interest (p < 0.05). The intensity of SPECT/CT tracer uptake in the medial and lateral knee compartment significantly correlated with varus or valgus alignment of the knee. A higher degree of osteoarthritis was significantly related to higher tracer uptake in the corresponding joint compartments. SPECT/CT reflects the specific loading pattern of the knee with regard to its alignment. It is also related to the degree of osteoarthritis. Hence, SPECT/CT should be considered for follow-up of patients after realignment treatments, osteotomies, deloader devices, or insoles.
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Kantonsspital Baselland-Bruderholz, CH-4101 Bruderholz, Switzerland. michael.hirschmann@ksbh.ch
authors.forename: Michael T
authors.initials: MT
authors.lastname: Hirschmann
authors.forename: Stephan
authors.initials: S
authors.lastname: Schön
authors.forename: Faik K
authors.initials: FK
authors.lastname: Afifi
authors.forename: Felix
authors.initials: F
authors.lastname: Amsler
authors.forename: Helmut
authors.initials: H
authors.lastname: Rasch
authors.forename: Niklaus F
authors.initials: NF
authors.lastname: Friederich
authors.forename: Markus P
authors.initials: MP
authors.lastname: Arnold
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D017760:Bone Malalignment / Q000000981:diagnostic imaging; D004164:Diphosphonates; D005260:Female; D006801:Humans; D007717:Knee / Q000000981:diagnostic imaging*; D007719:Knee Joint / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D004164:Diphosphonates; D015609:Organotechnetium Compounds; C060491:technetium Tc 99m hydroxydiphosphonate