Fatigue performance of a high-strength, degradable calcium phosphate bone cement

Reinforcement and Fatigue of a Bioinspired Mineral-Organic Bioresorbable Bone Adhesive

Bioresorbable bone adhesives may provide remarkable clinical solutions in areas ranging from fixation and osseointegration of permanent implants to the direct healing and fusion of bones without permanent fixation hardware. Mechanical properties of bone adhesives are critical for their successful application in vivo. Reinforcement of a tetracalcium phosphate-phosphoserine bone adhesive is investigated using three degradable reinforcement strategies: poly(lactic-co-glycolic) (PLGA) fibers, PLGA sutures, and chitosan lactate. All three approaches lead to higher compressive strengths of the material and better fatigue performance. Reinforcement with PLGA fibers and chitosan lactate results in a 100% probability of survival of samples at 20 MPa maximum compressive stress level, which is almost ten times higher compared to compressive loads observed in the intervertebral discs of the spine in vivo. High adhesive shear strength of 5.1 MPa is achieved for fiber-reinforced bone adhesive by tuning the surface architecture of titanium samples. Finally, biological and biomechanical performance of the fiber-reinforced adhesive is evaluated in a rabbit distal femur osteotomy model, showing the potential of the bone adhesive for clinical use.

Biologic osteosynthesis in the treatment of benign and malignant bone tumors

BACKGROUND AND OBJECTIVES

Mechanical augmentation with metal implants in the treatment of bone tumors limits magnetic resonance imaging and computerized tomography scan imaging due to the scattering effect. In addition, modulus of elasticity differences may cause chronic pain. We present a surgical technique in which cortical allografts are used as plates. This is a two-center experience focusing on functional and radiographic outcomes and complications.

METHODS

Under IRB approval, we performed a retrospective patient review. Demographics, treatment indications, tumor characteristics, and complications were collected. Radiographic studies were reviewed to determine the time to osseous incorporation. The last follow-up functional evaluation included the Musculoskeletal Tumor Society (MSTS) score, the Karnofsky scale, and Eastern Cooperative Oncology Group (ECOG).

RESULTS

Thirty patients, seventeen female and thirteen male, 16-year-old in average were included. The most common diagnoses were the humeral aneurysmal bone cyst and unicameral bone cyst. The Median follow-up was 6 years. Cortical allograft incorporation median time was 8.8 months whereas allograft void bone incorporation was 3 months. The average time to full weight-bearing without impact activity was 3.1 months. The most common complication was symptomatic hardware. Other complications included a superficial infection successfully treated with antibiotics, a temporary radial nerve neuropraxia, and an allograft fracture requiring revision surgery. Most patients had an MSTS score higher than 90 (excellent). Patients with malignant tumors had ECOG of 0 and a Karnofsky score of 100.

CONCLUSION

Biological osteosynthesis is a bone preserving and effective modality for mechanical augmentation with excellent functional results and low complication rates.