The aim of this study was to conduct the largest low contact stress (LCS) retrieval study to elucidate the failure mechanisms of the Porocoat and Duofix femoral component. The latter design was voluntarily recalled by the manufacturer. Uncemented LCS explants were divided into three groups: Duofix, Porocoat, and mixed. Demographics, polyethylene wear, tissue ingrowth, and metallurgical analyses were performed.Aims
Materials and Methods
This study aimed to develop a virtual clinic for the purpose of reducing face-to-face orthopaedic consultations. Anonymized experts (hip and knee arthroplasty patients, surgeons, physiotherapists, radiologists, and arthroplasty practitioners) gave feedback via a Delphi Consensus Technique. This consisted of an iterative sequence of online surveys, during which virtual documents, made up of a patient-reported questionnaire, standardized radiology report, and decision-guiding algorithm, were modified until consensus was achieved. We tested the patient-reported questionnaire on seven patients in orthopaedic clinics using a ‘think-aloud’ process to capture difficulties with its completion.Aims
Patients and Methods
Between 1988 and 1998 we implanted 318 total hip replacements (THRs) in 287 patients using the Plasmacup (B. Braun Ltd, Sheffield, United Kingdom) and a conventional metal-on-polyethylene articulation. The main indications for THR were primary or secondary osteoarthritis. At follow-up after a mean 11.6 years (7.6 to 18.4) 17 patients had died and 20 could not be traced leaving a final series of 280 THRs in 250 patients. There were 62 revisions (22.1%) in 59 patients. A total of 43 acetabular shells (15.4%) had been revised and 13 (4.6%) had undergone exchange of the liner. The most frequent indications for revision were osteolysis and aseptic loosening, followed by polyethylene wear. The mean Kaplan-Meier survival of the Plasmacup was 91% at ten years and 58% at 14 years. Osteolysis was found around 36 (17.1%) of the 211 surviving shells. The median annual rate of linear wear in the surviving shells was 0.12 mm/year and 0.25 mm/year in those which had been revised (p <
0.001). Polyethylene wear was a strong independent risk factor for osteolysis and aseptic loosening. The percentage of patients with osteolysis increased proportionately with each quintile of wear-rate. There is a high late rate of failure of the Plasmacup. Patients with the combination of this prosthesis and bearing should be closely monitored after ten years.
We followed 138 patients (145 hips) who had had uncemented total hip arthroplasty using the Taperloc femoral component for a mean of ten years (8 to 12.5). No patient was lost to follow-up; 31 (31 hips) died before the minimum time of eight years for inclusion in the study, and 30 of these still had their femoral component in place. One well-fixed prosthesis had been exchanged at the time of acetabular revision. Of the remaining 114 hips, one femoral component required revision for aseptic loosening and one for sepsis. Three other well-fixed femoral components were removed during acetabular revision. Complete clinical and radiological follow-up was obtained in the 109 hips which had not had revision. Clinically, 94 (87%) were rated good or excellent, eight (7%) fair and seven (6%) poor. The average Harris hip score increased from 48 before operation to 88 at the time of the last follow-up. Radiologically, 103 hips (94%) had fixation by bone ingrowth, three (3%) showed stable fibrous ingrowth and three (3%) were unstable. Osteolysis of the femoral cortex was seen in seven hips (6%), with major lysis in only one. At a mean follow-up of ten years, the results of the Taperloc femoral component are comparable with those of modern techniques of cementing in primary total hip arthroplasty.
