Little is known about the relationship between head-neck corrosion and its effect on the periprosthetic tissues and distant organs of patients hosting well-functioning devices. The purpose of this study was to investigate in postmortem retrieved specimens the degree and type of taper damage, and the corresponding histologic responses in periprosthetic tissues and distant organs. Fifty postmortem THRs (34 primaries, 16 revisions) retrieved after 0.5 to 26 years were analyzed. Forty-three implants had a CoCrMo stem and seven had a Ti6Al4V stem. All heads were CoCrMo and articulated against polyethylene cups (19 XLPE, 31 UHMWPE). H&E sections of joint pseudocapsules, liver, spleen, kidneys and lymph nodes were graded 1–4 for the intensity of various inflammatory cell infiltrates and tissue characteristics. Corrosion damage of the taper surfaces was assessed using visual scoring and quantitated with an optical coordinate measuring machine. SEM analysis was used to determine the acting corrosion mode. Polyethylene wear was assessed optically. The majority of tapers had minimal to mild damage characterized by local plastic deformation of machining line peaks. Imprinting of the stem topography onto the head taper surface was observed in 18 cases. Column damage on the head taper surface occurred in three cases. All taper surfaces scored moderate or severe exhibited local damage features of fretting and/or pitting corrosion. Moderate or severe corrosion of the head and/or trunnion was present in nine hips. In one asymptomatic patient with bilateral hips, lymphocyte-dominated tissue reactions involving perivascular infiltrates of lymphocytes and plasmacytes were observed. In this patient, mild, focal lymphocytic infiltrates were also present in the liver and kidneys, and there was focal histiocytosis and necrosis of the para-aortic lymph nodes. These two implants, which had been in place for 58.6 and 60.1 months, had severe intergranular corrosion of the CoCrMo trunnion, and column damage and imprinting on the head taper. In the other 41 hips, macrophage responses in the joint pseudocapsule to metallic and/or polyethylene wear particles ranged widely from minimal to marked. Focal necrosis in the pseudocapsules of 12 arthroplasties was related to high concentrations of CoCrMo, TiAl4V, TiO, BaSO4 and polyethylene wear particles. High concentrations of these particles were also detected in para-aortic lymph nodes. Rare to mild macrophages were observed in liver and spleen. This is a comprehensive study of wear and corrosion within well-functioning postmortem retrieved THRs, and the resulting local and distant tissue reactions. One of eight patients with moderate or severe corrosion did have a subclinical inflammatory response dominated by lymphocytes after five years. To what extent such an inflammatory process might progress to become symptomatic is not known. Ionic and particulate products generated by corrosion disseminated systemically. The minor lymphocytic infiltrate in the liver and kidneys of one subject with bilateral severely corroded head-neck junctions might suggest possible metal toxicity. The diagnosis of adverse tissue reactions to corrosion of modular junctions can be challenging. Postmortem retrieval studies add to our understanding of the nature and progression of lymphocyte-dominated adverse local and potentially systemic tissue reactions to corrosion of modular junctions

Introduction:. Sinus histiocytosis with massive lymphadenopathy (SHML) also known as Rosai – Dorfman disease is a disease of bone marrow stem cell origin. It affects lymph nodes primarily. Solitary bone lesions are very rare and can cause diagnostic difficulty. Aim:. To increase the awareness of SHML as a cause of cystic bone lesions. Materials and methods:. A 2 year old presented with 4 months history of pain and swelling of the distal forearm. There was no history of tuberculosis or HIV disease. The swelling was 4 × 3 cm firm, non-fluctuant and slightly tender. There were no lymph nodes. Radiographs showed an oval cystic lesion expanding with a well-defined margin. The ulnar cortex was deficient. CT scan confirmed a cystic lesion with contents of granulation tissue. The Hb and WCC were normal, ESR 20 was, CRP<5 and mantoux was negative. At surgery the lesion was curretted. The contents resembled tuberculous granulation but there was no caseation. The borders were well formed, the ulnar cortex was deficient. Results:. The histology revealed granulation tissue with numerous large histiocytes and immuno chemistry confirmed Rosai Dorfman disease. Healing with sclerosis was seen at 6 months. Discussion:. Rosai Dorfman disease is a systemic disease of bone marrow stem cells and lymphadenopathy is the prominent manifestation. Only ±8% of cases have been reported with bone involvement and 4% of these had no lymphadenopathy. The lesions are cystic and medullary but cortical involvement can occur. Solitary ossseous lesions characterized by a background of histocytes without eosinophils can mimic Langerhans histocytosis, localized osteomyelitis, fibrous dysplasia, tuberculosis, simple or aneurysmal bone cysts and metastatic deposits. Conclusion:. Lesions of haematopoetic origin should be considered in the diagnosis of lucent bone lesions in children

Introduction Localised Langerhans-cell histiocytosis of bone (eosinophilic granuloma) is a benign tumour-like condition with a variable clinical course. Different forms of treatment have been reported to give satisfactory results. However, previous series all contain patients with a wide age range. Our aim was to investigate the effect of skeletal maturity on the rate of recurrence of isolated eosinophilic granuloma of bone excluding those arising in the spine. Methods We followed-up 32 patients with an isolated eosinophilic granuloma for a mean of five years; 17 were skeletally immature. Results No recurrences were noted in the skeletally immature group even after biopsy alone. By contrast, four of 13 skeletally mature patients had a recurrence and required further surgery. Conclusions This suggests that eosinophilic granuloma has a low rate of recurrence in skeletally immature patients

Langerhans-cell histiocytosis (LCH) is a reactive proliferative disease characterized by the accumulation of abnormal histiocytes. The disease is broadly divided into two groups, unisystem and multisystem disease. The aetiology of LCH is unknown; the disease is currently accepted to be a reactive process rather than a malignancy. Localized LCH of bone is a benign tumour-like condition, which is characterized by a clonal proliferation of Langerhan’s-type histocytes, which infiltrate bone and cause osteolytic lesions. The common bones involved include – skull, pelvis, and diaphysis of long bones. We wanted to determine whether patient demographics at the time of presentation could help determine the clinical course and eventual outcome of the disease. We prospectively reviewed 68 patients with a primary diagnosis of LCH. Forty-six patients had unisystem disease, 22 had multisystem disease. There was a statistically significant difference in the age of presentation between the two groups. There were 6 deaths, all had multisystem disease. Of the 46 patients with unisystem disease, 31 (67.3%) underwent orthopaedic surgical intervention, 26 open biopsies and 5 curettage and bone grafting of lesions of the humeras (2), skin, clavicle and skull (1 each). There was a statistically significant difference in the average length of follow-up, between the 2 groups. We recommend closed and prolonged multidisciplinary follow-up of patient initially presenting with multisystem disease. Patients with unisystem disease can safely be discharged after a short follow-up period

Aims

We aimed to evaluate the utility of ⁶⁸Ga-citrate positron emission tomography (PET)/CT in the differentiation of periprosthetic joint infection (PJI) and aseptic loosening (AL), and compare it with ^99mTc-methylene bisphosphonates (^99mTc-MDP) bone scan.