Introduction and Objectives: The coating of implants with biomaterials seems to be a step further toward the ideal biological integration of an inert implant in live recipient bone where it will be subjected to load and movement. The goal of this study is to present results from 70 hip prostheses with implantation of a bioglass-coated stem.

Materials and Methods: The “Grupo para el Estudio del Biovidrio” [Group for the Study of Bioglass] and the Stazione del Vetro de Murano experimented with a biocompatible, osteoconductive bioglass in 1992, creating the Biovetro patent as the first bioglass used for the coating of the CRM total hip prosthesis (Seipi-Bio-implant). In 1992, implantation of this prosthesis was begun in Italy and Spain. In 1994 and 1995, we implanted 70 TiAlva CRM stem total hip prostheses with the proximal two-thirds coated with an 80-micron thick layer of Biovetro. A Ceraver-Osteal impacted cup covered with a titanium mesh was used in all cases.

Results: Of the 70 CRM prostheses implanted, adequate clinical and radiographic examination was possible in 62 cases, with an 8-year follow-up time. Clinical evaluation was done using the Merle D’Aubigne Postel criteria: pain, mobility, and gait. In 77% of patients, results were excellent or good, while 23% had fair or poor results. Radiographic evaluation according to Engh’s criteria for cementless stems showed 56 (90%) stable stems, 1 (1.6%) unstable stem, and 5 (8%) stem revisions, in one case due to infection. Survival rate for this stem at 8 years was 91.4%.

Discussion and Conclusions: Based on these results, we believe Biovetro coating produces worse osteointegration than HA due to: 1) Appearance of a fibrous interface with a macrophage foreign body reaction. 2) Less new bone formation activity and a significant delay in maturation. 3) Insufficient mineralization of newly-formed bone.

Objective: To assess the effect of the Active Spinal Rehabilitation Programme (ASRP) at four years after completion and its impact upon re-referral rates to General Practitioners and Orthopaedic Consultants.

Design: Patients included in the previous twelve-month follow-up study were sent a further explanatory letter and questionnaire including functional goal, exercise, analgesia intake, GP visit, consultant referral, employment status, revised Oswestry Low Back Pain Disability Index and Visual Analogue Scale (VAS)

Subjects: The first 140 patients completing the programme between April 1997–1998 were included in this study. An overall response rate of 85% (119 out of 140) was achieved with the aid of a follow-up telephone call (to those who did not respond to the postal questionnaire)

Results: The results obtained were comparable to those at one-year follow up. There was an improved VAS in 46% of the patients at four years post ASRP compared with VAS immediately after completion. The Oswestry Score was improved (decrease in patient perceived disability) in 55% of the patients. 56% of the patients achieved their functional goal and 83% felt in control of their pain. 57% of the patients did not visit their GP in the 12 months prior to the four-year follow up and 76% did not require Consultant referral after completing ASRP.

Conclusion: This study shows that the multiple benefits of an active spinal rehabilitation programme can be maintained for a four-year period, with a significant reduction in the demands on NHS resources.

Introduction: UHMWPE wear debris is known to be a major cause of periprosthetic osteolysis and the long-term failure of total joint replacements by a macrophage-mediated mechanism. The aim of this study was to compare the in vitro response of mononuclear phagocytes from patients undergoing total hip arthroplasty to challenge with polyethylene particles or stimulation with lipopolysaccharide (LPS).

Methods: Peripheral blood was taken from 2 healthy donors and 16 patients admitted to hospital to undergo total hip arthroplasty. Human mononuclear phagocytes were isolated by density centrifugation. Polyethylene particles were sequentially filtered to obtain biologically active particles (0.1–0.6 μm diameter). Cells plus particles, cells plus LPS and cells only were co-cultured in supplemented RPMI-1640 culture medium. Culture supernatants were harvested and the concentration of TNFα quantified by ELISA. Mean specific activity was calculated.

Results:.

When considering all the subjects, no correlation was found between the response of their cells to polyethylene particles and LPS stimulation. However the cells of four subjects gave a much higher response to LPS than the rest and when these where excluded the correlation between the response to LPS and PE particles was significant with an R² value of 0.9076.

Discussion: Despite the different mechanisms by which PE particles and LPS activate macrophages, the patient group with ‘normal’ or low response to LPS had a significant correlation in their response to LPS and particle stimulation. Why a small number of subjects had a much higher response to LPS without a proportional response to PE particles is not known, but it could be due to an increased expression of LPS receptors or genetic polymorphism. A greater than ten-fold difference in the patient response to particles may be of clinical importance in their potential susceptibility to loosening through osteolysis.