Female patients with low systemic BMD are prone to bone loss in Gruen zone 7 after cementless total hip arthroplasty.
OBJECTIVE
Factors that lead to periprosthetic bone loss following total hip arthroplasty (THA) may not only depend on biomechanical implant-related factors, but also on various patient-related factors. We investigated the association between early changes in periprosthetic bone mineral density (BMD) and patient-related factors.


METHODS
39 female patients underwent cementless THA (ABG II) with ceramic-ceramic bearing surfaces. Periprosthetic BMD in the proximal femur was determined with DXA after surgery and at 3, 6, 12, and 24 months. 27 patient-related factors were analyzed for their value in prediction of periprosthetic bone loss.


RESULTS
Total periprosthetic BMD was temporarily reduced by 3.7% at 3 months (p < 0.001), by 3.8% at 6 months (p < 0.01), and by 2.6% at 12 months (p < 0.01), but recovered thereafter up to 24 months. Preoperative systemic osteopenia and osteoporosis, but not the local BMD of the operated hip, was predictive of bone loss in Gruen zone 7 (p = 0.04), which was the only region with a statistically significant decrease in BMD (23%, p < 0.001) at 24 months. Preoperative serum markers of bone turnover predicted the early temporary changes of periprosthetic BMD. The other patient-related factors failed to show any association with the periprosthetic BMD changes.


CONCLUSIONS
Female patients with low systemic BMD show greater bone loss in Gruen zone 7 after cementless THA than patients with normal BMD. Systemic DXA screening for osteoporosis in postmenopausal patients before THA could be used to identify patients in need of prophylactic anti-resorptive therapy.
Alm
Jessica J
JJ
Orthopaedic Research Unit, Department of Orthopaedic Surgery and Traumatology, Turku University Central Hospital and University of Turku, Finland.
Mäkinen
Tatu J
TJ
Lankinen
Petteri
P
Moritz
Niko
N
Vahlberg
Tero
T
Aro
Hannu T
HT
D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000379:methods; D015519:Bone Density; D016723:Bone Remodeling / Q000502:physiology; D001862:Bone Resorption / Q000209:etiology; D002484:Cementation; D005260:Female; D005269:Femur / Q000503:physiopathology; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000150:complications / Q000601:surgery; D010024:Osteoporosis / Q000150:complications / Q000601:surgery; D012307:Risk Factors