Hip Instability Leading to Metallosis, Polyethylene Wear, and Failure of an Oxinium Femoral Head: A Case Report and Review of Literature

Oxinium is a zirconium metal alloy with an oxidized (ceramicized) surface that aims to mimic the superior wear properties of a ceramic femoral head while maintaining the high strength of metal-bearing surfaces. There are several reports that illustrate the wear and/or failure of Oxinium femoral heads following abnormal head contact with metal cup, with only a few studies reporting on the occurrence of metallosis. We present a case of metallosis and failure of Oxinium femoral head following two incidents of hip instability and one closed reduction. Successful revision was performed with cemented cup and metal femoral head, with 68 months of follow-up. We aimed to highlight the importance of achieving stable and well-oriented hip components when using Oxinium-bearing surfaces and to present a short literature review regarding the wear of oxidized zirconium-bearing surfaces in hip arthroplasty.

421 Intrapelvic Protrusion of a Femoral Head in A Ceramic-on-Ceramic Total Hip Replacement, A Case Report

Introduction Ceramic on ceramic bearing in Total Hip Replacement (THR) is associated with a low but evident risk of ceramic linear fracture, which can lead to catastrophic failure if not diagnosed and treated early. Case presentation: A 59-year-old male patient, who underwent a ceramic-on-ceramic THR 8 years ago, presented to our centre with a five-week history of right hip pain, after he suddenly twisted his upper body and felt a sharp pain in his groin. Prior to the injury he had an excellent functional level with the prosthesis. His examination findings confirmed a reduced range of movement with pain in the groin on internal and external rotation. X-ray and CT of the hip confirmed a ceramic liner fracture with protrusion of the femoral head into the pelvis. A revision THR was subsequently performed. Discussion The usual pattern of liner fracture in this type of bearings is that the femoral head stays contained inside the metal cup. In our case, the ceramic femoral head uniquely fractured the liner and passed into the pelvis. To the best of our knowledge, this is the third reported case in literature where a ceramic femoral head protrudes through the metal cup into the pelvis.

Mode I and II Wear in Ceramic on Ceramic Total Hip Arthroplasty: A Case Report

Introduction: Elective total hip arthroplasty (THA) is a common procedure and has been associated with favorable outcomes in both elderly and younger patients. A variety of implant and articular components exist so to allow surgeons to make a patient-specific choice with the intent of maximizing both patient outcomes and implant survival. The utilization of ceramic bearing surfaces during THA has become increasingly prevalent, with their tribological profile conveying favorable wear and osteolysis-resistant properties. Typically, ceramic articulating components are most susceptible to failure through brittle fracture or complications such as squeaking. Case Report: This case describes a 68-year-old Caucasian male who underwent revision of ceramic on ceramic THA due to pain, with intraoperative analysis revealing evidence of gross Mode I acetabular ceramic component wear with a resultant Mode II wear articulation between the ceramic femoral head and acetabular liner. Conclusion: Wear between ceramic implants in THA is infrequently reported, and as such awareness of this uncommon phenomena as well as its potential causative factors is important when considering either primary or revision THA involving ceramic bearing components. Keywords: Hip, arthroplasty, revision, ceramic, wear.

Mid-term outcomes of the R3™ delta ceramic acetabular system in total hip arthroplasty

Background Whilst bony fixation of hip replacement has stable solutions, there remains controversy over which bearing best optimizes longevity and function. Ceramic-on-ceramic (CoC) bearing combinations are associated with lower risk of revision due to aseptic loosening and dislocation. Evidence for long-term functional outcomes of modern, 4th generation CoC bearings is limited. The aim of this study was to analyze outcomes and complications of the R3™ Acetabular System (Smith & Nephew, Inc., Cordova, TN, USA) in combination with BIOLOX® Delta ceramic femoral head in patients undergoing primary total hip arthroplasty (THA). Methods Between June 2009 and May 2011, 175 patients (178 hips) were enrolled into a prospective, study at 6 sites in Europe and prospectively followed-up at 3 months and 1, 3, 5, and 7 years postoperative. Results Total WOMAC score improved from 63 (range, 22–91) preoperative to 8 (range, 0–8) at 1-year follow-up and remained unchanged at 7-year follow-up. Modified Harris hip score improved from 45 (range, 10–87) preoperative to 83 (range, 25–100) at 3 months, 91 (range, 42–100) at 1 year, and 92 (range, 46, 100) at 7 years. UCLA Activity Rating Scale score improved from 3.3 (range, 1–8) preoperative to 6.2 (range, 2–8) at 1 year; it marginally declined to 5.8 (range, 3–8) at 7-year follow-up. There were 4 trochanteric fractures and 5 patients died of unrelated reasons. Three hips were revised (2 periprosthetic fractures and 1 subluxation). The 7-year cumulative survival rate was 98.3%. Conclusion Clinical and functional improvements of THA with CoC bearing are maintained at 7 years postoperative. Trial registration ClinicalTrials.Gov, NCT03566082, Registered 10 January 2018—retrospectively registered,

Mid-term Outcomes of the R3™ Delta Ceramic Acetabular System in Total Hip Arthroplasty

Background: Whilst bony fixation of hip replacement has stable solutions, there remains controversy over which bearing best optimizes longevity and function. Ceramic-on-ceramic (CoC) bearing combinations are associated with lower risk of revision due to aseptic loosening and dislocation. Evidence for long-term functional outcomes of modern, 4th generation CoC bearings is limited. The aim of this study was to analyze outcomes and complications of the R3™ Acetabular System (Smith & Nephew, Inc., Cordova, TN, USA) in combination with BIOLOX® Delta ceramic femoral head in patients undergoing primary total hip arthroplasty (THA).Methods: Between June 2009 and May 2011, 175 patients (178 hips) were enrolled into a prospective, study at 6 sites in Europe and prospectively followed-up at 3 months and 1, 3, 5, and 7 years postoperative. Results: Total WOMAC score improved from 63 (range, 22-91) preoperative to 8 (range, 0- 8) at 1-year follow-up and remained unchanged at 7-year follow-up. Modified Harris Hip Score improved from 45 (range, 10-87) preoperative to 83 (range, 25-100) at 3 months, 91 (range, 42-100) at 1 year, and 92 (range, 46, 100) at 7 years. UCLA Activity Rating Scale score improved from 3.3 (range, 1-8) preoperative to 6.2 (range, 2-8) at 1 year; it marginally declined to 5.8 (range, 3-8) at 7-year follow-up. There were 4 trochanteric fractures and 5 patients died of unrelated reasons. Three hips were revised (2 periprosthetic fractures and 1 subluxation). The 7-year cumulative survival rate was 98.3%. Conclusion: Clinical and functional improvements of THA with CoC bearing are maintained at 7 years postoperative. Trial registration: ClinicalTrials.Gov, NCT03566082, Registered 10 January 2018 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03566082

Stand up! Are normal weight-bearing forces sufficient for a 12/14 Morse taper locking in total hip arthroplasty?

Background: The aim of this study was to investigate total hip arthroplasty (THA) Morse taper pull-off strengths after impaction prior to cyclical loading compared to cyclical loading alone. The practical relevance of the experiment is to provide a perspective on what may be clinically satisfactory taper assembly given the spectrum of head tapping patterns used by surgeons, as well as compare traditional impaction performed in standard THA with alternate methods of taper engagement such as ‘ in situ assembly’ used in micro-invasive techniques. Methods: 36 taper constructs utilising a combination of cobalt-chrome alloy and ceramic-titanium alloy junctions were investigated in vitro in wet and dry conditions with cyclical loading of the constructs. Taper disengagement strengths with and without impaction were compared. Secondary investigation of the surface roughness of the heads and tapers was also assessed. Results: An impaction to a wet taper resulted in a greater pull off force compared to a dry taper with a CoCr head and taper combination. Impacting the head and dryness of the taper did not affect pull off forces of a ceramic femoral head on titanium taper. Pulling a head off a taper significantly alters the head surface roughness. Conclusion: Impaction of a taper does not provide any benefit over cyclical loading of a taper assembly alone for pull-off strength.

Long-term Outcomes of the R3™ Delta Ceramic Acetabular System in Total Hip Arthroplasty

Background: Whilst bony fixation of hip replacement has stable solutions, there remains controversy over which bearing best optimizes longevity and function. Ceramic-on-ceramic (CoC) bearing combinations are associated with lower risk of revision due to aseptic loosening and dislocation. Evidence for long-term functional outcomes of modern, 4th generation CoC bearings is limited. The aim of this study was to analyze outcomes and complications of the R3™ Acetabular System (Smith & Nephew, Inc., Cordova, TN, USA) in combination with BIOLOX® Delta ceramic femoral head in patients undergoing primary total hip arthroplasty (THA).Methods: Between June 2009 and May 2011, 175 patients (178 hips) were enrolled into a prospective, study at 6 sites in Europe and prospectively followed-up at 3 months and 1, 3, 5, and 7 years postoperative. Results: Total WOMAC score improved from 63 (range, 22-91) preoperative to 8 (range, 0- 8) at 1-year follow-up and remained unchanged at 7-year follow-up. Modified Harris Hip Score improved from 45 (range, 10-87) preoperative to 83 (range, 25-100) at 3 months, 91 (range, 42-100) at 1 year, and 92 (range, 46, 100) at 7 years. UCLA Activity Rating Scale score improved from 3.3 (range, 1-8) preoperative to 6.2 (range, 2-8) at 1 year; it marginally declined to 5.8 (range, 3-8) at 7-year follow-up. There were 4 trochanteric fractures and 5 patients died of unrelated reasons. Three hips were revised (2 periprosthetic fractures and 1 subluxation). The 7-year cumulative survival rate was 98.3%. Conclusion: Clinical and functional improvements of THA with CoC bearing are maintained at 7 years postoperative.