Retrospective analysis of all uncemented massive endoprostheses inserted at our unit in the management of primary bone tumours with a minimum follow up of 5 years.

Methods. The case notes and radiographs of all patients were reviewed. The group consisted of a total of 52 patients of which 4 (8%) were lost to follow up. Kaplan-Meier Cumulative Survival Graphs were created for mortality, amputation, revision and infection for the whole group and for each individual prosthesis.

Results. The mean follow up was seven years (63–107 months). The average age at time of insertion was 19 years; twenty-six patients were skeletally immature. The majority of implants were distal femoral (31) and proximal tibial (14). Osteosarcoma was the commonest diagnosis.

The rate of infection was 12.5%, aseptic loosening 6%, amputation due to local recurrence 10% and the mortality 21%.

All the deaths occurred within 3 years of the implant being inserted and were all due to systemic progression of the disease. The amputations for local recurrence occurred throughout the follow up period, the latest being at 71 months. Revisions for infections and aseptic loosening all occurred early (within 3 years). All cases of aseptic loosening occurred in distal femoral replacements (10%) and were related to divergent canals. Proximal tibial replacements had the highest rate of infection (23%). Rates of infection were not higher in the minimally invasive grower (12.5 %) when compared to the group as a whole.

Conclusion. We have shown a reduced rate of aseptic loosening (6%), particularly in the skeletally immature, when compared to our units results for cemented fixed hinged prostheses. The uncemented prosthesis is a successful implant that needs careful consideration, especially in the skeletally immature. Careful preoperative planning and surgical technique are of the utmost importance.

Retrospective analysis of 25 consecutive metal on metal proximal femoral replacements performed at our unit between 1965 and 1979.

Methods. Patients were: clinically evaluated using the Modified Harris Hip and Enneking Scoring Systems and radiologically using the ISOLOS scoring system.

The concentration of Cr, Co, Ti, Al, V, Mo & Ni in whole blood and urine was also measured by High-Resolution Inductively Coupled Mass Spectrometry and compared with controls and patients with other implants.

Retrieved prostheses (in situ for in excess of 25 years) were analysed for roughness and wear using a Mitutoya form tracer and an electron microscope.

Results. Thirteen patients have since died; nine from metastatic disease and four from other causes. Of the remainder, eleven (44%) are still alive, five still retaining metal on metal articulations and one has been lost to follow up. They have been in situ for an average of 32 years. The average modified Harris Hip score is 76 (53–93) and the average Enneking Score is 74 (63–90).

In the retrieved prostheses the contact zones were found to be smoother (Ra 0.05?m), have fewer and smaller carbides together with evidence of ‘self-healing’ when compared to the original surface (Ra 0.32?m).

Blood & urine levels of Co & Cr were significantly elevated. Co levels were exceptionally elevated in loose prostheses but levels quickly fell following revision.

Conclusion. We have shown the potential longevity of metal on metal arthroplasty. The wear seen in retrieved specimens is low and we might expect to improve the fixation by reducing the torque with apical bearing and encouraging extra-cortical bone bridging with hydroxy-apatite coated collars. Elevated serum and urine Co levels may well predict a loose prosthesis and may be useful as a screening tool.

We performed a retrospective analysis of massive endoprostheses inserted at our unit in the management of Giant Cell Tumours of the distal femur with a minimum follow up of 5 years.

Methods. Twenty-five massive articulating endoprostheses were inserted between 1986 and 1998 at our unit. The case notes and radiographs of all patients were reviewed. A functional and radiological analysis was performed using the MTOS and ISOLS scoring systems. Kaplan-Meier Cumulative Survival Graphs were created for amputation and revision for septic and aseptic loosening. Two patients had died (8%) from unrelated causes. No cases were lost to Follow Up.

Results. Massive replacements were performed for stage 3 (aggressive), pathological fracture (30%) or recurrent disease. The mean follow up was twelve years (range 5–18 years). The average age at time of insertion was 37 years; no patients were skeletally immature. Fifteen implants were fixed hinge devices and ten were rotating hinge devices with HA collars (since 1993). No cases were revised for sepsis. There had been no cases of recurrent disease or amputation. There have been six (26%) revisions for aseptic loosening. Only one of these occurred in the rotating hinge and HA collar group. In the fixed hinge group (38% aseptic loosening rate) revision occurred after an average of six years. There have also been five re-bushings all of which have occurred in the fixed hinge group. The average MTOS score was 74 (range 47–97).

Conclusion. Young patients with fixed hinged devices developed a high incidence of aseptic loosening. They also had a significant rate of re-bushing. Results of the rotating hinge prosthesis with HA collar were much more promising. Functional scores were good after a period of twelve years despite the young age group.

We report the case of a 12-year-old boy with polyostotic fibrous dysplasia of the upper femur in whom a massive customised polyethylene prosthesis functioned successfully for more than fifty years.