Purpose: The cause of Paget’s disease, osteitis deformans, defined by increased bone resorption followed by excessive attempts at repair, remains unclear. The current hypothesis is that bone is slowly infected by paramyxovirus in genetically predisposed patients. We report the case of a patient with monostotic Paget’s disease of the pelvis which was transferred to the homolateral distal femur after total hip arthroplasty.

Case report: A 66-year-old man with Paget’s disease of the hemi-pelvis developed pagetic hip deformation requiring a total hip arthroplasty performed in 1993. A Charnley-Kerboull cemented prosthesis was implanted. The medullary canal was plugged with fragments of cancellous bone harvested from the acetabulum (drill holes required to achieve rotatory stability of the acetabulum). One year later, an asymptomatic osteolytic lesion of the distal femur was identified at the level of the medullary plug. Hip function remained excellent despite extension to the distal and proximal femur. All inflammatory parameters were normal and the femoral component was not loosened. 99m-technetium scintigraphy revealed strong uptake in the pelvis but also in the distal femur under the femoral stem. Isolated femoral stem revision was performed in 1996 as a preventive measure against stress fracture. Pathology analysis of surgical specimens identified Paget’s disease (osteoclast hyperactivity, mosaic aspect of the osteoblasts. After femoral revision with a long stem and medical treatment with biphosphonates, the osteolytic lesion disappeared progressively, taking on the classical sclerous sequelar aspect of osteitis deformans. The disease remained quiescent six years after revision. Hip function remained excellent at last follow-up.

Discussion and conclusion: This is the first report of this type of complication after total hip arthroplasty. This observation that Paget’s disease can be transferred via a autologous cancellous bone graft is in favour of the viral hypothesis, suggesting osteoclastic infection by contiguity. This complication has never been observed with frozen or radiated allograft material although such material may have been harvested from pathological bone, notably with Paget’s disease

Purpose: Revision total knee arthroplasty (RTKA) is particularly difficult and results more variable than primary total knee arthroplasty due to the added problem of bone loss. Massive bone allografts have been proposed to restore bone stock and mechanical conditions as close to the physiological situation as possible. The purpose of this retrospective analysis was to assess clinical and radiological results after knee reconstruction with massive allografts in patients undergoing revision total knee arthroplasty.

Materials and method: This series included 14 patients who underwent a revision procedure between February 1990 and August 1998 for RTKA with segmentary bone loss and bone defects. This group included seven patients with mechanical failure and seven others with septic loosening. Reconstruction was achieved with a massive allograft sealed around a long stem cemented implant. The composite assembly was impacted into the patient’s bony segment. The allografts were used to reconstruct the distal femur in nine cases, the proximal tibia in one, and both in the others. The IKS score and radiographic homogenisation of the host-graft junction were assessment criteria.

Results: Mean follow-up was 50 months (24–110). Mean IKS score was significantly improved from 43 (11–70) pre-operatively to 75 (40–100) at last follow-up (Wilcoxon test, p = 0.002). At last follow-up, the flexion-extension amplitude was 91±10°. Radiographic integration of the allografts was achieved in 14 out of 18 grafts. Three allografts were resorbed leading to fracture with subsequent implant failure and a new revision in two. There were no infections.

Discussion and conclusion: Bone grafts may be a solution to the difficult problem of bone loss during RTKA. Massive grafts combined with long stem implants have given encouraging early and mid-term results. The duration of these results is under evaluation.

Purpose: New surfaces have been developed to reduce polyethylene wear. The zircone ceramic surface appears to have a theoretical advantage due to its interesting tribologic properties. The purpose of this prospective study was to assess clinical and radiological outcome at a minimal two years follow-up in a consecutive series of total hip arthroplasties using the polyethylene zircone junction.

Material and methods: La series included 56 total hip arthroplasties performed in 49 patients (30 women and 19 men), mean age 52.2 ± 12 years (25–76). Primary degenerative hip disease was the aetiology in 43% of the cases, dysplasia in 27%. The femoral component was made of 316L steel with a 11°25 Morse cone for 27 hips and a 5°40 cone for 29 hips. The femoral head measured 22.2 mm and was made of polycrystaline zircone ceramic stabilised in the tragonal form with yttrium (Y-TZP). All the arthroplasties were performed via transtrochanteric access using cemented Charnley-Kerboull implants. Clinical outcome was assessed with the Merle-d’Aubigné score. Classical landmarks on the AP pelvis views were used to assess implant migration. Cup wear was measured using the Livermore method. Actuarial survival curves were plotted.

Results: Mean follow-up was 32 months (24–48). None of the patients were lost to follow-up. The mean functional score at last follow-up was 17.8±0.2 (16–18) versus 12.2±2.6 before arthroplasty (Student t test for paired variables, p < 0.0001). No cases of migration of the femoral or acetabular component were observed. Acetabular wear was always less than the precision of the measurement method. Osteolytic lesions were however observed as endosteal defects in the Merkel region measuring less than 1 cm2, observed in 18 out of the 56 hips (32%). These osteolytic lesions generally appeared between the first and second year and did not appear to progress.

Discussion: Osteolysis in the Merkel region appeared early for one third of the hips, despite the absence of cup polyethylene wear. It would be reasonable to be prudent when using zirone ceramic heads. We are continuing our close follow-up of this group of patients. In addition, measurements of wear and migration are being made using the EBRA method.

Purpose: Rapidly destructive degeneration of the hip joint is a condition whose relations with habitual degenerative hip disease are poorly understood. This uncommon condition is observed in 5 to 10% of patients with degenerative hips and almost always requires arthroplasty; The objectives of this retrospective study were to determine the distinctive radiological and clinical features of this condition and assess long-term outcome after total hip arthroplasty in these patients.

Material and methods: The study concerned 100 total hip arthroplasties performed between 1984 and 1088 in 67 men and 11 men, mean age 71 years with rapidly destructive degeneration of the hip joint. All arthroplasties were implanted via the transtrochanteric approach with cemented Charnley-Kerboul implants. Mean follow-up was seven years ten months.

Results: There were seven complications: two nonunions of the trochanter, three extensive periprosthetic ossifications, one recurrent case of dislocation, and one late infection by blood stream dissemination. At last follow-up, 95 hips exhibited excellent or very good function (Poste-Merle-d’Aubigné classification). Fixation was stable for 94 ace-tabular implants and 97 femoral implants. Six acetabular implants and three femoral implants had loosened. These femoral loosenings were always associated with acetabular loosening. Four hips required revision surgery: one for non-union of the trochanter, one for septic loosening, and two for asepctic loosening.

Discussion: This study confirmed the radiological definition and the clinical features of this condition and demonstrated the reliability of the pathology examination of the femoral head and the articular capsule. Among the different hypotheses put forward to explain this condition, we cannot retain the presence of joint over-use, or use of anti-inflammatory drugs, nor infirm a micro-crystalline or vascular origin. Nevertheless, the vascular phenomena observed in the femoral head are comparable to those observed in joint lesions subsequent to ischaemia. Total hip arthroplasty causes considerable blood loss, estimated at 2706 ml (haematocrit 35%), apparently much higher than during arthroplasties using an identical technique for patients with the usual form of degenerative hip disease. Excepting this fact, complications, clinical outcome and arthroplasty longevity were not different than those generally observed.

Purpose of the study: Extensive loss of femoral bone subsequent to implant loosening raises an unsolved problem. The purpose of this work was to examine mid-term results of 18 iterative total hip arthroplasties with femoral reconstruction using massive allografts performed between 1986 and 1997.

Materials and methods: Using the Vives classification, the femoral bone lesions were grade 3 (n = 2) and grade 4 (n = 16). The reconstruction was achieved with radiated massive allografts measuring 11 to 35 cm implanted in a split host femur. Charnley-Kerboull implants with a long stem were cemented in the reconstructed femurs.

Results: Mean follow-up was 4 years 10 months (range 2 to 9 years). Nine complications in 7 hips were observed: 6 trochanter nonunions, two recurrent prosthesis dislocations and 1 femoral fracture. At last follow-up, the functional result was excellent or very good in 12 hips (Merle d’Aubigné classification). A stable fixation persisted for 15 implants and 3 had loosened. Graft-host femur consolidation was achieved in all cases except 1. There were 3 cases with extensive resorption of the graft including 2 associated with loosening of the femoral component.

Discussion: Reconstruction of the femur after extensive bone loss using a massive allograft appears to be a useful method for restoring bone tissue and providing immediate mechanical support for the femur.