Long-term outcomes after Instrumented Bone Preserving total elbow arthroplasty: a radiostereometric study with a minimum follow-up of 10 years.

BACKGROUND: Aseptic loosening is a main concern in elbow arthroplasty. Evaluation of implant migration using radiostereometric analysis (RSA) might increase understanding of implant loosening. Previously, 2-year RSA results of 16 Instrumented Bone Preserving (IBP) elbow prostheses showed migration of the humeral component in the first weeks but most components stabilized within 6 months postoperatively. In follow-up, the present study evaluated long-term survival, the relation between early migration and survival, and the long-term migration and clinical outcomes. METHODS: Sixteen patients who received an IBP prosthesis were prospectively followed with a median follow-up time of 136 months (range 82-165). Migration was measured using RSA. Clinical results were described using the Elbow Function Assessment (EFA), Broberg and Morrey elbow functional rating index, Oxford Elbow Score (OES), and visual analog scale (VAS) for pain and satisfaction. RESULTS: Four patients underwent a revision within 10 years, and 2 more were planned for revision surgery after 14 years. Five patients died with their prosthesis in situ. Early migration was not associated with survival. Long-term migration patterns varied widely. Median EFA score was 58.5, Broberg and Morrey score was 50, and OES score was 32. Median VAS score for pain was 2 and that for satisfaction was 7.5. CONCLUSION: Ten-year survival of the IBP total elbow prosthesis was 75%, decreasing to 63% after 14 years of follow-up. Long-term implant failure could not be predicted by 2-year migration results in this study. Although short-term clinical results were promising, long-term outcomes worsened in all patients.

Effective radiation dose in radiostereometric analysis of the hip.

Background and purpose - Radiostereometric analysis (RSA) is the gold standard to study micromotion of joint replacements. RSA requires the acquisition of additional radiographs increasing the radiation dose of patients included in RSA studies. It is important to keep this dose as low as possible. Effective radiation dose (ED) measurements of RSA radiographs for different joints were done by Teeuwisse et al. some years ago using conventional radiology (CR); for total hip arthroplasty (THA), Teeuwisse et al. reported an ED of 0.150 milliSievert (mSv). With the modern digital radiography (DR) roentgen technique the ED is expected to be less.Material and methods - In this phantom study, simulating a standard patient, the ED for hip RSA radiographs is determined using DR under a variety of different roentgen techniques. The quality of the RSA radiographs was assessed for feasibility in migration analysis using a (semi-)automatic RSA analysis technique in RSA software.Results - A roentgen technique of 90 kV and 12.5 mAs with additional 0.2 copper (Cu) + 1 mm aluminum (Al) external tube filters results in an ED of 0.043 mSv and radiographs suitable for analysis in RSA software.Interpretation - The accumulated ED for a standard patient in a 2-year clinical hip RSA study with 5 follow-up moments and a double acquisition is below the acceptable threshold of 1.0 mSv provided by the EU radiation guideline for studies increasing knowledge for general health.

Multiple Perforations of the ECRB Tendon Using an Innovative Standardized, Reproducible Technique; A Cadaveric Study on Accuracy and Prospective Clinical Safety Assessment Pilot Study. No Adverse Effects in the First 122 Patients with Lateral Epicondylitis.

Background: In LE (Lateral Epicondylitis) otherwise known as Tennis Elbow, the Extensor Carpi Radialis Brevis (ECRB) tendon is most commonly involved. In the majority of studies, injections are performed with a lack of standardization. The Instant Tennis Elbow Cure (ITEC) device has been developed to perform reproducible and standardized perforations by multiple needles. The goal of this pilot study was to estimate the accuracy of this ITEC device by means of a cadaveric study and to assess the clinical safety of this procedure. Methods: Ten cadaveric arms were injected using the ITEC device. The location and depth of the ECRB tendon was measured by ultrasound imaging. The accuracy of the infiltration was assessed by locating the injected dye through dissection and arthrotomy of the cadaveric elbow. A prospective clinical pilot study was conducted to assess the safety of the ITEC device in treating patients with chronic LE. An optional infiltration with an injection fluid was carried out?? Primary outcome measures were side effects and complications of the ITEC device occurring within a follow up period of 8 weeks after treatment. Results: In all cadaveric elbows the injection fluid ( in this case an injection fluid) was located at the ECRB tendon. In one cadaver, a minimal amount of dye was found intra-articular and in 3 cadavers a small quantity was located in the surrounding tissue of the ECRB tendon. 122 patients with LE were treated with the ITEC device. No adverse effects or complications were reported at 8-week follow up. Conclusion: Treatment of LE using the ITEC device appears accurate and safe. It may improve future research since it is reproducible and it can be performed in a standardized way.