Subchondral defects in caprine femora augmented with in situ setting hydroxyapatite cement, polymethylmethacrylate, or autogenous bone graft: biomechanical and histomorphological analysis after two‐years

Abstract

Juxta-articular defects pose significant challenges due to the high risk of fracture of the subchondral plate and articular cartilage. We evaluated the mechanical and histomorphological repair process of caprine subchondral femoral defects augmented with either a bioresorbable in situ setting hydroxyapatite cement (HAC), potymethylmethacrylate (PMMA), autogenous bone graft (AG), or left empty, Twelve-mm subchondral defects were made bilaterally in the medial femoral condyles of skeletally mature goats and augmented with a test material or left empty. Femurs were harvested at varying time periods out to 2 years and evaluated for subchondral stiffness and histomorphological indices. Several defects augmented using autograft or left empty sustained focal fracture of the subchondral plate. No HAC or PMMA augmented defects showed evidence of subchondral fracture. The HAC and PMMA augmented defects showed comparable stiffness at all time points. The mean volume fraction of HAC remaining within the defects progressively decreased from 96% at 24 h to 38% at 2 years. The new bone replacing the HAC appeared to have normal physiological architecture and orientation. In situ setting hydroxyapatite cement may be a viable alternative for the repair of subchondral defects with an important advantage that while undergoing gradual resorption and replacement with host bone, mechanical integrity of the skeletal defect is maintained.

Standardised cement augmentation of the PFNA using a perforated blade: A new technique and preliminary clinical results. A prospective multicentre trial

“…This supports the theory that there is no thermal damage to the bone due to the exothermic reaction of the PMMA in a standardised augmentation setting with only a small amount of cement injected. 26,28 The mean cement volume of 4.2 ml used in our study was able to increase stability in biomechanical investigations. 14,20,23,26 However, with this small amount of cement damage to the bone is unlikely.…”

“…13,23,24 However, several studies report no damage to the cartilage or the bone itself by cement augmentation. [25][26][27][28] The current prospective multicentre study was undertaken to evaluate the early clinical results and the technical performance of the new standardised augmentation for the PFNA blade. To our knowledge, this is the first report on this device.…”

Long-term results of the augmented PFNA: a prospective multicenter trial

“…The main concerns about such a device were a potential disturbance of bone metabolism [14,19,37] and the induction of cartilage damage although there are several investigations rebutting this [4,41,43]. The current prospective multicenter trial was conducted to evaluate the long-term clinical outcome as well as the radiological results with the standardized augmentation of the PFNA.…”

Supplemental Bone Grafting in Giant Cell Tumor of the Extremity Reduces Nononcologic Complications

“…This may result in cartilage damage, fracture, and arthrosis [13,15,28]. Bone graft has the ability to incorporate into host bone and more adequately restore the subchondral and cancellous positions of the joint surface [7,8,32].…”