Influence of varying stem and metaphyseal sleeve size on the primary stability of cementless revision tibial trays used to reconstruct AORI IIA defects. A simulation study

Traditionally, diaphyseal stems have been utilized to augment the stability of revision total knee replacement (rTKR) implants. More recently metaphyseal augments, such as sleeves, have been introduced to further augment component fixation. The effect of augments such as stems and sleeves have on the primary stability of a rTKR implant is poorly understood, however it has important implications on the complexity, costs and survivorship of the procedure. Finite element analysis was used to investigate the primary stability and strain distribution of various size stems and sleeves used in conjunction with a cementless revision tibial tray. The model was built from computer tomography images of a single healthy tibia obtained from an 81‐year‐old patient to which an Anderson Orthopaedic Research Institute (AORI) IIA defect was virtually added. The influences of varying body mass index (BMI) and bone modulus were also investigated. Stemless sleeves were found to provided adequate primary implant stability (average implant micro‐motion <50 μm) for the studied defect. Addition of a stem did not enhance the primary stability. Furthermore, this study found that varying BMI and bone modulus had a considerable effect on strain distribution but negligible effect on micro‐motion in the sleeve area. In conclusion, the addition of diaphyseal stem to a metaphyseal sleeve had little benefit in enhancing the primary stability of tibial trays augmented when simulating reconstructions of AORI IIA tibial defects. Additional studies are required to determine the relative benefit of the diaphyseal stem when using metaphyseal sleeves defects with more extensive bone loss. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1876–1886, 2018.

     

Minimum 10-Year Outcome of One-Stage Total Hip Arthroplasty Without Subtrochanteric Osteotomy Using a Cementless Custom Stem for Crowe III and IV Hip Dislocation

Background

Options for total hip arthroplasty (THA) in high dislocated hips include subtrochanteric osteotomy (STO), high hip center positioning, and 2-stage surgery with progressive lowering using an external fixator before THA. We described the long-term results of 1-stage THA performed without STO, using a cementless customized stem associated if necessary with sequential tenotomies and/or greater trochanteric osteotomy.

Cementless Total Knee Arthroplasty in Knee Osteonecrosis Demonstrated Excellent Survivorship and Outcomes at Three-Year Minimum Follow-Up

Background

Lack of consensus exists on the use of cementless total knee arthroplasty (TKA) in patients with knee osteonecrosis. Therefore, this study was conducted to evaluate (1) implant survivorship; (2) clinical outcomes and complications; and (3) radiographic outcomes of primary cementless TKA in knee osteonecrosis.

Cementless Posteriorly Stabilized Total Knee Arthroplasty: Seven-Year Minimum Follow-Up Report

Background

The purpose of this study is to evaluate (1) implant survivorship; (2) patient outcomes; (3) complications; and to (4) perform a radiographic analysis of cementless posteriorly stabilized total knee arthroplasty (TKA) patients at a minimum of 7-year follow-up.

Polyethylene Wear and Osteolysis Is Associated With High Revision Rate of a Small Sized Porous Coated THA in Patients With Hip Dysplasia

The outcome of 25 primary THAs in patients with hip dysplasia using the AML Bantam femoral stem (DePuy) is reported. Age at operation averaged 43 ± 10 years. Twenty-two of 25 stems were cementless. All cementless acetabular components had conventional or cross-linked polyethylene and screws. Follow-up averaged 11 ± 5 years (range 4–18). Four cementless stems were revised after 3, 4, 8, and 9 years; 2/3 cemented stems were revised at 8 and 18 years. Femoral revisions demonstrated extensive conventional polyethylene wear, periprosthetic osteolysis and loosening. Five entire cups were revised for wear and loosening; four liners were replaced. Harris Hip Scores for patients with retained stems went from 43 ± 12 to 85 ± 13. High revision rates with the proximally porous coated Bantam stem are due to loss of fixation, often associated with polyethylene wear and osteolysis.     

Effects of Micro-Arc Oxidation Coating on Outcomes of a Cementless Grit-Blasted Tapered-Wedge Stem in Total Hip Arthroplasty

To evaluate the effects of micro-arc oxidation (MAO) coating on the outcomes of a grit-blasted tapered-wedge stem in total hip arthroplasty (THA), we performed a retrospective review of 141 THAs using MAO coated stem for a minimum of 5 years and compared them to 219 THAs using the same geometry stem without MAO coating. Harris hip score improved from 43.7 points preoperatively to 93.9 points postoperatively. No hips were revised for aseptic loosening. Complications included one squeaking hip, one iliopsoas tendonitis, and one deep vein thrombosis. Postoperative Harris hip scores, WOMAC scores, UCLA activity scores, stem stabilities, and complication rates did not differ between the groups. After medium-term follow-up, our findings did not support the use of MAO coating on grit-blasted tapered-wedge stem to improve clinical outcomes.     

Midterm Results of Large Diameter Biolox Forte Ceramic Head on Delta Ceramic Liner Articulation in Total Hip Arthroplasty

Seventy-nine patients (94 hips), who underwent cementless alumina-on-alumina total hip arthroplasty (THA) with the use of a 36-mm delta ceramic liner-on-alumina ceramic femoral head, were followed for an average of 6.5 years (range, 5–7.7 years). All acetabular and femoral components were bone-ingrown and neither pelvic nor femoral osteolysis was identified until the latest follow-up. The survivorship with revision surgery as an endpoint was 97.9% (95% confidence interval = 100%–95%). Ceramic related complications such as fracture and squeaking did not occur in any patient. The mid-term results of cementless THA with this type of ceramic articulation are encouraging.     

Comparison Between Preassembled and Modular Cups in Primary Cementless Total Hip Arthroplasty: A Two-Year Minimum Follow-up Study

We prospectively analyzed 83 patients who underwent ceramic-on-ceramic THA using preassembled (n = 22) or modular acetabular components (n = 61) between June 2010 and June 2012. There were no significant differences in mean postoperative radiographic outcomes, functional outcomes, or complications between the two groups. Both groups showed satisfactory performance at the 2 year follow up. Only the gender of the patients was significantly different between the two groups. Half of the women had smaller acetabular diameters accommodating a cup size of only 48-50-mm. Although a preassembled cup with a 36-mm ceramic liner is proven to be safe in the short term, future research should focus on evaluating the long-term risks.     

Cementless Hip Arthroplasty in Paget’s Disease at Long-Term Follow-Up (Average of 12.3 Years)

We present a long-term follow-up report of 33 cementless total hip arthroplasties in 27 patients who have an established diagnosis of Paget’s disease. The medium term results of this series were reported in 2007 (Lusty et al. Journal of Arthroplasty. 2007;22:692). Fourteen cases were available for follow-up at an average of 12.3 years (range 10–17). Harris Hip scores improved from 56/100 preoperatively (16–98/100) to 83/100 post operatively (72–90/100). All surviving components were radiographically ingrown. Based on these findings, cementless total hip arthroplasty has a good long-term outcome in Paget’s disease.     

Vanadium release in whole blood,serum and urine of patients implanted with a titanium alloy hip prosthesis

Abstract

Introduction. Vanadium (V) is a minor constituent of the Titanium–Aluminum–Vanadium (TiAlV) alloy currently used in cementless hip prostheses. Present study aimed at verifying the correlation of vanadium levels among different matrices and assessing reference levels of the ion in a population of patients wearing a well-functioning hip prosthesis. Methods. Vanadium was measured using Inductive Coupled Plasma Mass Spectrometry (ICP-MS) in whole blood, serum and urine of 129 patients implanted with a TiAlV-alloy hip prosthesis. Results. The values in the serum were above the upper limit of the reference values in 42% of patients (29% in urine and 13% in whole blood). A good correlation among matrices was observed (p < 0.001). The cohort of patients (N = 32) complaining of pain or in which a loosening or damage to the prosthesis was assessed showed a significantly higher excretion of vanadium in urine as compared with the remaining asymptomatic patients (p = 0.001). The 95th percentile distribution of vanadium in the cohort of patients with a well-functioning prosthesis was 0.3 μg/L in whole blood, 0.5 μg/L in serum and 2.8 μg/L in urine, higher that in the unexposed population, especially for urine. Conclusions. The presence of a prosthesis, even though well-functioning, may cause a possible release of vanadium into the blood and a significant urinary excretion. The reference values of vanadium of the asymptomatic patients with titanium alloy hip prostheses supplied information regarding the background exposure level of the ions and their lower and upper limits.