Cement augmentation of hip implants in osteoporotic bone: How much cement is needed and where should it go?

Abstract

Several studies proved the beneficial effect of cement augmentation of proximal femoral nail antirotation (PFNA) blades on implant purchase in osteoporotic bone. We investigated the effect of different localizations and amounts of bone cement. Polyurethane foam specimens were instrumented with a PFNA blade and subsequently augmented with PMMA bone cement. Eight study groups were formed based on localization and amount of cement volume related to the blade. All specimens underwent cyclic loading with physiological orientation of the force vector until construct failure. Foam groups were compared between each other and to a cadaveric control group. The experiments revealed a significant dependency of implant purchase on localization and amount of cement. Biomechanically favorable cement positions were found at the implant tip and at the cranial side. However, none of the tested augmentation patterns performed significantly inferior to the cadaveric benchmark. These findings will allow surgeons to further reduce the amount of injected PMMA, decreasing the risk of cement leakage or cartilage damage. With the use of fixation devices like helical blades for treating proximal femoral fractures, the incidence of cut-out of cephalic implants has decreased.1-5 Nevertheless failures occur. Besides surgeon-related factors such as quality of the reduction and implant positioning, bone quality plays an important role in the occurrence of mechanical complications. 6,7 Due to the aging population and relatively poor compliance to drugs that prevent osteoporotic fractures, the incidence of osteoporosis related fractures will increase.

Does Metaphyseal Cement Augmentation in Fracture Management Influence the Adjacent Subchondral Bone and Joint Cartilage?

“… 32 Furthermore, this was confirmed by a qualitative analysis of HRpQCT scans of cement-augmented osteoporotic human cadaveric bones from previous augmentation studies. 2 , 3 , 10 …”

The PFNA® Augmented in Revision Surgery of Proximal Femur Fractures

“…2 ), which is indicated at the handle, and thus the cement flow direction can be controlled. A recent study by Sermon et al reported that the greatest improvement in stability was achieved with an augmentation cranial to the blade and at the tip of the blade [14]. The amount of injected cement was in accordance with the defect in the bone stock resulting from the former osteosynthesis and was monitored intraoperatively using fluoroscopy.…”

Anchorage strategies in geriatric hip fracture management

“…The authors of this multicenter trial reported no head necrosis or blade migration. Especially, patients with poor bone quality seemed to profit and less amount of cement was used in these cases to avoid complications [60]. After an assessment of bone quality [61], cement augmentation of osteoporotic fractures or compound osteosynthesis is recommended in individual cases [60].…”