Bone has a remarkable capacity to heal. However, in some instances the amount of bone which is needed to heal exceeds its healing capacity. Due to reported issues with current treatments there is continued research into alternative approaches with a view to producing an off the shelf alternative to the gold standard autologous bone transplants. The current investigated the use of a chitosan/hydroxyapatite scaffold, which was used to covalently bone morphogenetic protein and vascular endothelial growth factor using a UV crosslinking process. Results indicate that the incorporation of hydroxyapatite increased the mechanical properties of the scaffold compared to chitosan alone. Furthermore, crosslinking was confirmed using swelling studies and FTIR analysis. Elisa indicated that physiological doses of BMP were released after 10 days while in vitro testing did not indicate a cytotoxic response to the scaffold. In vivo testing in a rat femoral defect model indicated the efficacy of the treatment with scaffolds containing BMP and VEGF in combination resulting in more bone in the defect compared to the scaffold alone 8 weeks post-surgery.

Purpose: The purpose of the study is to compare the disease severity at the time of surgical intervention between patients undergoing primary joint replacement under the National Health Service and Private Health-care Systems.

Materials: 166 patients were included in the study – 101 NHS and 65 Private. Inclusion criteria were: 1) hip or knee osteoarthritis, 2) primary joint replacement, and 3) informed consent of the patient. Patients with arthropathy of inflammatory, infectious or neoplastic aetiology were excluded. Physician evaluation included medical history, calculation of Charleson Comorbidity Scores, and Knee Society rating. Patients were given self-assessment health questionnaires including WOMAC, SF-36, and Nottingham Health Profile.

Results: Mean age was 69.4 years and did not vary significantly between NHS and Private groups. Charleson Comorbidity Scores were significantly worse in the NHS group than in the private. Health assessment questionnaire scores were all adjusted for age, sex, and comorbidity. In NHS patients undergoing TKR, we demonstrate significantly worse pre-operative comorbidity than in private group for indices of function and pain. Patients undergoing THR showed little difference in pre-operative comorbidity.

Conclusion: NHS patients undergoing primary TKR have significantly more advanced disease than their counterparts who are privately insured. Access to TKR surgery is determined by the healthcare delivery system rather then a threshold level of disease severity. Further follow-up of the outcomes of TKR in these two groups needs to be carried out to determine the long-term effects of accessing surgical care at a more advanced stage of disease.