Cementation for femoral head osteonecrosis: a preliminary clinic study

Core Decompression and Bone Marrow Aspiration Concentrate Grafting for Osteonecrosis of the Femoral Head

BACKGROUND

Core decompression (CD) with bone marrow aspiration concentrate (BMAC) is a technique that may improve outcomes in osteonecrosis of the femoral head (ONFH). The primary aim of this study was to evaluate the radiographic progression free survival (PFS) of CD augmented with BMAC. Secondary aims were to determine the survivorship with conversion (CFS) to total hip arthroplasty (THA) as an endpoint, determine prognostic factors, and characterize the cellular quality of the BMAC.

METHODS

A retrospective cohort study of 61 femoral heads (40 patients) was performed. Patient demographics, comorbidities, BMI, smoking status, etiology, location and extent of ONFH were recorded. The primary endpoint was radiographic progression of ONFH and secondarily, conversion to THA. Additional aims were to determine predictive factors for progression and report the cellular characteristics of the BMAC. Data obtained were compared to the results of a prior randomized controlled trial comparing CD alone versus CD with polymethylmethacrylate cement (PMMA) augmentation.

RESULTS

Radiographic PFS of CD with BMAC at 2 and 5 years was 78.3% and 53.3%, respectively. The risk of progression was lower in the CD with BMAC group compared to CD alone (HR0.45, p = 0.03), however this difference no longer remained statistically significant on multivariate analysis. Conversion to total hip arthroplasty free survival (CFS) of CD with BMAC at both 2 and 5 years was 72.1% and 54.6%, respectively with no differences compared to the control groups (CD alone, CD and PMMA). The predictive factors for progression were obesity (BMI ≥ 30) and the extent of the disease as quantified by either percentage involvement, necrotic index or modified necrotic index.

CONCLUSIONS

No differences in PFS or CFS between CD with BMAC compared to CD alone or CD with PMMA were identified. Independent statistically significant predictors of progression-free survival or conversion to THA are BMI ≥ 30 and the extent of ONFH. Further research with an adequately powered randomized controlled trial is needed.

LEVEL OF EVIDENCE

3.

Treatment of aseptic osteonecrosis of the femoral head: Historical aspects

The treatment of aseptic osteonecrosis (ON) of the femoral head has been the subject of numerous therapeutic and surgical proposals due to the absence of medical treatment with proven efficacy. For many years, the goal of surgical treatment was to avoid total hip replacement (THR) with uncertain survival in patients considered too young (30-50 years) for this procedure. Numerous conservative treatments were thus proposed: core decompression with numerous variants, non-vascularized and vascularized bone grafts, intertrochanteric and rotational transtrochanteric osteotomies, cementing. The lack of a common classification and a lack of knowledge of natural history complicated the interpretation of the results for a long time. Nevertheless, it appeared that these treatments were effective only in the very early stages and among these in the limited ONs, medial rather than central and especially lateral, with discrepancies according to etiologies apart from sickle cell disease recognized by all as being pejorative. For the same reason, partial arthroplasties have been attempted and abandoned in turn: femoral head total and partial resurfacing and femoral prosthesis. The most recent advances are stem-cell-enhanced core decompression and progress in total arthroplasty, whose reliability has made it possible to extend the indications to increasingly younger patients seeking treatment with guaranteed or near-guaranteed efficacy. Most of the other interventions have disappeared or almost disappeared because of their lack of effectiveness especially in extensive and post-fracture ONs, sometimes because of their complexity and the length of their post-operative management, and also because they complicate and penalize a future total arthroplasty. This argues for early detection of ON at an early stage where the "head can be saved" by stem cell augmented core decompression, a minimally invasive treatment that leaves the chances of success of a THR intact.

Lantern-shaped screw loaded with autologous bone for treating osteonecrosis of the femoral head

Background

Treatment for osteonecrosis of the femoral head (ONFH) in young individuals remains controversial. We developed a lantern-shaped screw, which was designed to provide mechanical support for the femoral head to prevent its collapse, for the treatment of ONFH. The purpose of this study was to investigate the efficacy and safety of the lantern-shaped screw loaded with autologous bone for the treatment of pre-collapse stages of ONFH.

Methods

Thirty-two patients were randomly divided into two groups: the lantern-shaped screw group (core decompression and lantern-shaped screw loaded with autogenous bone) and the control group (core decompression and autogenous bone graft). During 36 months follow-up after surgery, treatment results in patients were assessed by X-ray and computed tomography (CT) scanning as well as functional recovery Harris hip score (HHS).

Results

Successful clinical results were achieved in 15 of 16 hips (94%) in the lantern-shaped screw group compared with 10 of 16 hips (63%) in the control group (p = 0.0325). Successful radiological results were achieved in 14 of 16 hips (88%) in the lantern-shaped screw group compared with 8 of 16 hips (50%) in the control group (P = 0.0221).

Conclusion

The lantern-shaped screw loaded with autologous bone for the treatment of pre-collapse stages of ONFH is effective and results in preventing progression of ONFH and reducing the risk of femoral head collapse.

Trial registration

The trial registration number: ChiCTR-TRC-13004078 (retrospectively registered at 2013-11-28).

Angiogenic Rg1 /Sr-Doped TiO2 Nanowire/Poly(Propylene Fumarate) Bone Cement Composites

A new approach is provided for preparing radiopaque and angiogenic poly(propylene fumarate) (PPF) bone cements by integrating Sr-doped n-TiO₂ nanowires and ginsenoside Rg1 suitable for treating osteonecrosis. High aspect ratio radiopaque TiO₂ -nanowires are synthesized by strontium doping in supercritical CO₂ for the first time, showing a new phase, SrTiO₃ . PPF is synthesized using a transesterification method by reacting diethyl fumarate and propylene glycol, then functionalized using maleic anhydride to produce terminal carboxyl groups, which are subsequently linked to the nanowires. The strong interfacial adhesion between functionalized PPF and nanowires is examined by scanning electron microscopy, Fourier transform infrared, X-ray photoelectron spectroscopy, thermal analysis, and mechanical testing. An angiogenic modulator, ginsenoside Rg₁ , is integrated into the bone cement formulation with the mechanical properties, radiopacity, drug release, and angiogenesis behavior of the formed composites explored. The results show superior radiopacity and excellent release of ginsenoside Rg₁ in vitro, as well as a dose-dependent increase in the branching point numbers. The present study suggests this new methodology provides sufficient mechanical properties, radiopacity, and angiogenic activity to be suitable for cementation of necrotic bone.

Synthesis and characterization of novel TiO2-poly(propylene fumarate) nanocomposites for bone cementation

A novel composite material made from poly(propylene fumarate) (PPF) and titania nanofibers has been synthesized for potential use as an orthopaedic biomaterial with TiO₂ nanofibers chemically linked to the PPF matrix as a reinforcing phase to enhance its mechanical properties.

Adipose-Derived Stem Cells Enhance Bone Regeneration in Vascular Necrosis of the Femoral Head in the Rabbit

Osteonecrosis of the femoral head was induced in rabbits by intramuscular injection of methylprednisolone and vascular occlusion of the capital femoral epiphysis by electrocoagulation. Eight weeks later the animals received no treatment (group A), core decompression by drilling a hole (diameter 1.2 mm) from the outer cortex 2.5 cm distal to the proximal end of the greater trochanter (group B), or injection of 107 autologous adipose-derived stem cells (ADSCs) directly into the femoral head (group C). Eight weeks later, microcomputed tomography scans indicated that bone and trabecular volume and density were significantly higher in group C than in other groups. Histology indicated more new bone formation in group C than in other groups. Group C showed strong osteocalcin immunoreactivity in subchondral bone osteoblasts in the necrotic femoral head, whereas few osteocalcin-positive cells were found among osteoblasts in other groups. Thus, autologous ADSC transplantation improved osteogenesis and the microstructure of vascular deprivation-induced osteonecrotic tissue.

A poly(propylene fumarate)--calcium phosphate based angiogenic injectable bone cement for femoral head osteonecrosis

Osteonecrosis of the femoral head commonly occurs when the blood supply to bone was disrupted. The general treatment for early stages of necrosis in the femoral head is core decompression. However, the long-term outcome of this operation is usually compromised due to collapse of the necrotic bone. In this study, poly(propylene fumarate) (PPF) and calcium phosphate cement (CPC) were combined to provide appropriate mechanical strength after core-decompressed femoral heads and offer the properties of osteoconductivity. Effects of different ratios of CPC to PPF on mechanical and cytotoxicity were investigated. Results show that bone cement is less cytotoxic with the C/P ratio raise, and the increment of the CPC proportion also strengthens the mechanical strength, reduces the crosslinking temperature and diminishes excessive swelling of the cement. With addition of ginsenoside Rg1 the bone cement composite can also offer angiogenic effect. The drug release profiles were analyzed and the angiogenecity of released Rg1 was confirmed by the assay of tube formation in human umbilical vein endothelial cells (HUVECs). In summary, the newly developed angiogenic bone cement composite possesses remarkable development potential for application to treating osteonecrosis of the femoral head.

Calcium phosphate cement to prevent collapse in avascular necrosis of the femoral head

Subchondral and articular collapse following nontraumatic osteonecrosis of the femoral head is an important cause of osteoarthritis in patients between ages 20 and 40. Because hip arthroplasty in the younger population is prone to early wear and failure, it is paramount to prevent collapse once osteonecrosis is detected. Natural remodeling of the osteonecrotic areas by adjacent normal bone is predominated by osteoclastic resorption, which weakens the cancellous bone and allows microfractures to occur before full healing can take place. Current treatment modalities include core decompression and various adjuncts such as bone graft, mesenchymal stem cells and tantalum implants to provide structural integrity and to speed bony creeping substitution. Calcium phosphate cement has been reported in the treatment of fractures, especially depressed tibial plateau fractures. It is slow to resorb and is gradually replaced by bone, allowing prolonged support of periarticular fractures during healing. We hypothesize that calcium phosphate cement in conjunction with standard decompression of osteonecrotic femoral head lesions can prevent collapse.

Inefficacy of the cementation of femoral head collapse in glucocorticoid-induced osteonecrosis

The objective of this paper was to assess the efficacy of cementation of the femoral head in stage III glucocorticoid-induced osteonecrosis. Ten hips (nine patients) were treated by the injection of low-viscosity cement to reduce the collapse. The follow up included clinical and radiological assessments preoperatively and at 3, 6 and 12 months after surgery. The visual analogue scale (VAS) score, the Lequesne index and the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score did not show any significant improvement. Eight of the ten hips showed a worsening of the collapse and required total hip arthroplasty during follow up. The mean time before total hip replacement was 8.6 +/- 7 months. The other two hips did not show any relapse of collapse nor functional worsening at the maximum follow up of 5 years. Our results suggest that cement injection is not a treatment that should be proposed for glucocorticoid-induced osteonecrosis.

Temporal and spatial expression of BMP-2 in sub-chondral bone of necrotic femoral heads in rabbits by use of extracorporeal shock waves

BACKGROUND AND PURPOSE

Extracorporeal shock wave treatment has been used successfully for the treatment of avascular necrosis of the femoral head. The pathway of biological events by which this is accomplished has not been fully elucidated. BMP-2 is a key mediator of bone development and repair, and is uniquely required for bone formation. We therefore examined the effect of extracorporeal shock waves on induction of BMP-2 in necrotic femoral heads.

METHODS

Femoral head necrosis was induced in rabbits by treatment with methylprednisolone and lipopolysaccharide. BMP-2 expression was assessed by immunohistochemistry, quantitative real-time PCR, and western blot analysis. Histomorphometric analysis was performed to evaluate the rate of bone formation in femoral heads treated with extracorporeal shock waves.

RESULTS

Extracorporeal shock wave treatment was associated with a significant increase in expression of BMP-2 protein and mRNA in the subchondral bone of the necrotic femoral heads. Moreover, the most intensive immunostaining of BMP-2 was observed in the proliferative zone above the necrotic zone. Histomorphometric analysis showed that extracorporeal shock wave treatment significantly increased the rate of bone formation in the subchondral bone.

INTERPRETATION

We conclude that extracorporeal shock wave treatment significantly upregulates the expression of BMP-2 in necrotic femoral heads. The process of repair of femoral head necrosis is accelerated by the use of extracorporeal shock waves.

Impacted bone and calcium phosphate cement for repair of femoral head defects: a pilot study

Bone impaction grafting has been advocated for reconstruction of femoral head osteonecrosis. However, bone grafts do not prevent the progression of collapse and subsequent disabling osteoarthritis in late-stage osteonecrosis. We hypothesized reconstruction of large subchondral defects with a mix of impacted morsellized cancellous bone grafts and calcium phosphate cement would afford mechanical stability allowing remodeling into new bone without femoral head collapse. In a pilot study we created a critically sized subchondral defect model in 15 goats following the trapdoor procedure. Defects were left empty (n = 3), filled with morsellized cancellous bone grafts (n = 6), or filled with a mixture of morsellized cancellous bone and calcium phosphate cement (n = 6). No defects collapsed by sacrifice at 12 weeks. Defects filled with morsellized cancellous bone showed complete incorporation and remodeling to a normal trabecular structure. In the morsellized cancellous bone/calcium phosphate cement group, most of the calcium phosphate cement was resorbed in 12 weeks and the mixture was largely replaced by fibrous or fatty marrow. Although the specific mixture did not confirm our hypothesis, we suspect a slower resorbing calcium phosphate cement remains a promising material to mix with morsellized cancellous bone to treat late stages of femoral head osteonecrosis.

Percutaneous drilling for the treatment of secondary osteonecrosis of the knee

Osteonecrosis of the knee comprises two separate disorders, primary spontaneous osteonecrosis which is often a self-limiting condition and secondary osteonecrosis which is associated with risk factors and a poor prognosis. In a series of 61 knees (38 patients) we analysed secondary osteonecrosis of the knee treated by a new technique using multiple small percutaneous 3 mm drillings. Total knee replacement was avoided in 59 knees (97%) at a mean follow-up of 3 years (2 to 4). Of the 61 knees, 56 (92%) had a successful clinical outcome, defined as a Knee Society score greater than 80 points. The procedure was successful in all 24 knees with small lesions compared with 32 of 37 knees (86%) with large lesions. All the procedures were performed as day cases and there were no complications. This technique appears to have a low morbidity, relieves symptoms and delays more invasive surgery.

Nontraumatic osteonecrosis of the femoral head: ten years later

The etiology of osteonecrosis of the hip may have a genetic basis. The interaction between certain risk factors and a genetic predisposition may determine whether this disease will develop in a particular individual. The rationale for use of joint-sparing procedures in the treatment of this disease is based on radiographic measurements and findings with other imaging modalities. Early diagnosis and intervention prior to collapse of the femoral head is key to a successful outcome of joint-preserving procedures. The results of joint-preserving procedures are less satisfactory than the results of total hip arthroplasty for femoral heads that have already collapsed. New pharmacological measures as well as the use of growth and differentiation factors for the prevention and treatment of this disease may eventually alter our treatment approach, but it is necessary to await results of clinical research with long-term follow-up of these patients.

Osteonecrosis: etiology, diagnosis, and treatment

PURPOSE OF REVIEW

This review provides an update of the recent progress in etiology, pathogenesis, diagnosis, and treatment of osteonecrosis.

RECENT FINDINGS

Concerning pathogenesis, there is evidence that there is a genetic predilection for those who are exposed to the two leading etiologic associations for osteonecrosis: corticosteroids and alcohol. Studies concerning the treatment of osteonecrosis indicate that most preservative (ie, joint-sparing) procedures available today have better results in the precollapse stages of the disease and in smaller lesions. Therefore, researchers continue to develop and modify diagnostic techniques, particularly relating to MRI, for the identification and quantification of osteonecrotic lesions. Advances concerning bone grafting and arthroplasty procedures have resulted in improved clinical outcomes for this patient population. The future treatment of osteonecrosis may involve genetic or cell-based therapies.

SUMMARY

Although progress has been made, considerably more research is needed before we fully understand this disease. Hopefully, such research will lead to effective measures for saving the femoral head or, better yet, preventing osteonecrosis.