Raised levels of metal ions in the blood in patients who have undergone uncemented metal-on-polyethylene Trident-Accolade total hip replacement.

The issues surrounding raised levels of metal ions in the blood following large head metal-on-metal total hip replacement (THR), such as cobalt and chromium, have been well documented. Despite the national popularity of uncemented metal-on-polyethylene (MoP) THR using a large-diameter femoral head, few papers have reported the levels of metal ions in the blood following this combination. Following an isolated failure of a 44 mm Trident-Accolade uncemented THR associated with severe wear between the femoral head and the trunnion in the presence of markedly elevated levels of cobalt ions in the blood, we investigated the relationship between modular femoral head diameter and the levels of cobalt and chromium ions in the blood following this THR. A total of 69 patients received an uncemented Trident-Accolade MoP THR in 2009. Of these, 43 patients (23 men and 20 women, mean age 67.0 years) were recruited and had levels of cobalt and chromium ions in the blood measured between May and June 2012. The patients were then divided into three groups according to the diameter of the femoral head used: 12 patients in the 28 mm group (controls), 18 patients in the 36 mm group and 13 patients in the 40 mm group. A total of four patients had identical bilateral prostheses in situ at phlebotomy: one each in the 28 mm and 36 mm groups and two in the 40 mm group. There was a significant increase in the mean levels of cobalt ions in the blood in those with a 36 mm diameter femoral head compared with those with a 28 mm diameter head (p = 0.013). The levels of cobalt ions in the blood were raised in those with a 40 mm diameter head but there was no statistically significant difference between this group and the control group (p = 0.152). The levels of chromium ions in the blood were normal in all patients. The clinical significance of this finding is unclear, but we have stopped using femoral heads with a diameter of ≤ 36 mm, and await further larger studies to clarify whether, for instance, this issue particularly affects this combination of components.

Paget's Osteosarcoma - no Cure in Sight.

UNLABELLED: Purpose Paget' s osteosarcoma has a fearful reputation with a quoted survival of at best 5% at 5 years.We therefore reviewed our experience of 26 patients treated over the last 25 years using modern staging and limb salvage techniques to see if there had been any improvement in survival. SUBJECTS: We identified 26 patients on the Royal Orthopaedic Hospital Oncological database with a diagnosis of sarcoma secondary to Paget's disease. RESULTS: The survival rate was 53% at 1 year, 25% at 2 years and no patient survived for 5 years.The median survival was 21 months for those treated with curative intent and 7 months for those treated palliatively. Four of the five patients treated with limb-sparing surgery developed local recurrence between 5 and 12 months, the fifth died at 14 months.There was no difference in survival between amputation and limb salvage. DISCUSSION: The development of sarcomatous change in Paget's disease is well recognised. It represents an important segment of primary bone tumours in patients over 40 years of age.The prognosis is appalling. Indeed only 15 of 368 cases (4%) from a number of historical series have survived more than 5 years. Our results are similarly disappointing with no survivors at 5 years despite modern methods of management of bone tumours.While there is no difference in local recurrence rates or survival between limb reconstruction and limb ablation the poor prognosis for both means that neither can be recommended at present. Sarcomatous change in Pagetoid bone should therefore be regarded as a different disease to primary osteosarcoma. It remains an incurable disease with a poor prognosis.