4 research outputs found
Long Cephalomedullary Nails Can Be a Cheap and Effective Interval Revision Prosthesis in Infected Hip Replacements That Require Proximal Femoral Replacement: A Small Case Series
No full textHip prosthetic joint infection management is complex and expensive, especially in severe bone loss. Reducing the price of interval prosthesis when performing staged revision could minimize costs without compromising outcomes. We present 2 similar techniques developed independently that use an antibiotic-coated cephalomedullary nail with a total hip arthroplasty bearing (head and cemented acetabular component) attached to it as an interval proximal femoral replacement prosthesis. Using this technique, the femoral implant cost was reduced up to 10-fold. All patients have recovered well with resolution of infection and functional recovery similar to patients undergoing proximal femoral replacement. In one case, the lag screw (femoral neck) fractured at 5 months prompting the second-stage revision. This complication should be considered when deciding the timing of second-stage revisions in these cases.Boopalan Ramasamy, Aaron Scott Hammat, Renjy Nelson, Stuart Adam Callary, Ping Keung Chan, Lucian Bogdan Solomo
Wear of Highly Cross-Linked Polyethylene in Primary Total Hip Replacement
No full textBackground: The most common causes for revision of total hip replacement (THR) are periprosthetic osteolysis and loosening, both related to wear of the acetabular component. Acetabular components utilizing highly cross-linked polyethylene (XLPE) have been shown to wear less than earlier conventional polyethylene. Reported in vivo XLPE wear rates vary due to differing radiographic measurement techniques and methods of reporting results. XLPE liners are manufactured using different amounts of cross-linking, which may influence wear, as may articulation size and patient age. Aims: The aims of this thesis were to (1) validate radiostereometric analysis (RSA) as the most accurate radiographic method to measure wear of XLPE acetabular components, (2) undertake a scoping review of RSA studies of XLPE wear, and (3) measure bedding-in and wear rate of XLPE using RSA to investigate the influence of: i) type of XLPE, ii) articulation size, and iii) patient age. Methods: The validation study used a hip phantom to compare known two-dimensional (2D) movements of the femoral head within an acetabular component to movements measured radiographically using RSA, Hip Analysis Suite (HAS), PolyWare, Ein Bild Roentgen Analyse (EBRA) and Roentgen Monographic Analysis Tool (ROMAN). The scoping review incorporated a systematic search of PubMed, Scopus and Cochrane databases to identify studies which used RSA to measure XLPE wear. Patients in six cohorts, differing in XLPE type, articulation size or patient age, underwent regular RSA examinations to calculate XLPE wear rates between one and five years. Results: RSA was significantly more accurate to measure 2D wear and had less variability in error than all other methods. Articulation size influenced accuracy of HAS and ROMAN measurements. Use of different acetabular reference segments did not influence accuracy of RSA. The scoping review identified 14 publications by other authors that in combination reported XLPE wear at 2–10 years follow-up of 10 primary THR cohorts comprising 209 hips. Mean proximal wear rate ranged from 0.00 to 0.06 mm/yr. However, differences in how wear was determined limited comparability between studies. Recommendations were made to enhance standardization of reporting wear. RSA studies undertaken as part of this thesis found that mean proximal bedding-in within the first year and the 2D and 3D wear rates between one and five years were higher in hips with a Marathon XLPE liner, which is manufactured with a lower radiation dose. Mean proximal wear rate was low for each of the six cohorts. Articulation size and age did not influence the wear rate at five years. Conclusion: The superior accuracy of RSA wear measurements allow much smaller cohorts to be used in clinical wear studies. The scoping review and RSA studies confirmed the low early wear rates of XLPE components irrespective of articulation size and patient age. One type of XLPE liner had a higher wear rate at five years compared to other XLPE liners. Longer-term wear rates and the relationship between XLPE and periprosthetic osteolysis are yet to be determined.Thesis (Ph.D.) -- University of Adelaide, Adelaide Medical School, 201
The variation in hip stability measurements between supine and standing radiographs of dysplastic hips
No full textAIMS: The aims of this study were to compare clinically relevant measurements of hip dysplasia on radiographs taken in the supine and standing position, and to compare Hip2Norm software and Picture Archiving and Communication System (PACS)-derived digital radiological measurements. METHODS: Preoperative supine and standing radiographs of 36 consecutive patients (43 hips) who underwent periacetabular osteotomy surgery were retrospectively analyzed from a single-centre, two-surgeon cohort. Anterior coverage (AC), posterior coverage (PC), lateral centre-edge angle (LCEA), acetabular inclination (AI), sharp angle (SA), pelvic tilt (PT), retroversion index (RI), femoroepiphyseal acetabular roof (FEAR) index, femoroepiphyseal horizontal angle (FEHA), leg length discrepancy (LLD), and pelvic obliquity (PO) were analyzed using both Hip2Norm software and PACS-derived measurements where applicable. RESULTS: Analysis of supine and standing radiographs resulted in significant variation for measurements of PT (p < 0.001) and AC (p = 0.005). The variation in PT correlated with the variation in AC in a limited number of patients (R2 = 0.378; p = 0.012). CONCLUSION: The significant variation in PT and AC between supine and standing radiographs suggests that it may benefit surgeons to have both radiographs when planning surgical correction of hip dysplasia. We also recommend using PACS-derived measurements of AI and SA due to the poor interobserver error on Hip2Norm.Ameya Bhanushali, Mukai Chimutengwende-Gordon, Martin Beck, Stuart Adam Callary, Kerry Costi, Donald W. Howie, Lucian Bogdan Solomo
The effect of weight compared to BMI on patient reported outcomes at long term follow up of primary total hip arthroplasty
No full textIntroduction: Obesity has been linked to the development of osteoarthritis meaning that a large portion of arthroplasty patients are overweight or obese. Whilst the short-term complications associated with obesity are well described there is a paucity of evidence on the effect of weight compared to BMI for long term functional outcomes of total hip replacements (THR). The aim of this study was to investigate the influence of BMI and weight on long-term patient reported outcome measures following primary THR. Methods: 846 patients who underwent primary THR at the Royal Adelaide Hospital between 2000 and 2009 had a pre-operative height and weight recorded. Patient reported outcome measures (PROMs) were completed at 1, 5 and greater than 10 years follow-up. Categorical comparison of PROMs was performed for patients in weight categories of 0–65 kg, 65–80 kg, 80–95 kg, 95–110 kg and >110 kg; and BMI categories as per the WHO Classifications. Results: There was no difference in absolute or change in PROMs for any weight category. BMI did not have an effect on the change in (HHS), however there was a statistically significant decrease in absolute (HHS) values at 1 and 5 years with increasing obesity. 65 patients underwent revision within the first ten years. Conclusion: The results from this study confirm for the first time that there was no impact of weight or BMI on the change in long-term PROMs of THR. There remains a need for larger registry studies to investigate the effect of weight and BMI on long-term patient outcomes and revision rate.Thomas S. Robertson, Stuart Adam Callary, Kerry Costi, Robyn Janice Clothier, Kamalesh Venugopal, Mark Rickma
