Bone quality, and the combination and penetration of cement–bone interface: A comparative micro-CT study of osteoarthritis and rheumatoid arthritis

To compare the microstructure, bone quality, and the combination and penetration of cement–bone interface in tissue specimens from patients with osteoarthritis (OA) and rheumatoid arthritis (RA). A total of 80 femoral condyle tissue specimens from 20 OA patients (40 condyles) and 20 RA patients (40 condyles) who underwent total knee arthroplasty at the Department of Orthopaedics in Tengzhou Central People's Hospital were collected between January 2017 and September 2017. According to the random number table method, 20 specimens from the OA group were defined as group A, and 20 specimens in the RA group were defined as group B. The bone quality parameters were measured by micro-CT. The remaining 20 specimens in the OA group and the remaining 20 specimens in the RA group were defined as group C and group D, the cement–bone interfaces were established by the self-made bone cement compression device, and were analyzed by micro-CT. Micro-CT measurement revealed that the bone volume fraction (BV/TV), trabecular thickness (Tb.Th), and trabecular number (Tb.N) in group A were significantly higher than those in group B (all P < .05). The bone surface/bone volume (BS/BV), structure model index (SMI), trabecular separation (Tb.Sp), and degree of anisotropy (DA) in group A were significantly lower than those in group B (all P < .05). The penetration depth of bone cement in group D was significantly greater than those in group C via x-ray detection. The bone quality of OA patients is better than that of RA patients, but the combination and penetration of cement–bone interface of RA patients are better than that of OA patients. The findings advance our understanding of knee prosthesis and have important clinical implications, but they require validations in future studies with larger sample sizes.