Adverse Local Tissue Reaction due to Mechanically Assisted Crevice Corrosion Presenting as Late Instability Following Metal-on-Polyethylene Total Hip Arthroplasty.

Background: Mechanically assisted crevice corrosion (MACC) at modular junctions can cause a spectrum of adverse local tissue reactions (ALTRs) in patients who have undergone total hip arthroplasty (THA). The purpose of this study is to describe the presentation, treatments, and related complications of a cohort of patients presenting with late instability following metal-on-polyethylene THA due to underlying MACC and ALTR.

Methods: This multicenter retrospective case series presents 17 patients (12 women, mean age 62.

Fourier transform infrared spectroscopic imaging of wear and corrosion products within joint capsule tissue from total hip replacements patients.

Implant debris generated by wear and corrosion is a prominent cause of joint replacement failure. This study utilized Fourier transform infrared spectroscopic imaging (FTIR-I) to gain a better understanding of the chemical structure of implant debris and its impact on the surrounding biological environment. Therefore, retrieved joint capsule tissue from five total hip replacement patients was analyzed.

Metal wear particles in hematopoietic marrow of the axial skeleton in patients with prior revision for mechanical failure of a hip or knee arthroplasty.

Wear particles generated by hip and knee arthroplasties disseminate to the liver and spleen with the highest concentrations observed in subjects who have had a failed arthroplasty. We asked to what extent metallic particles could also disseminate to remote hematopoietic bone marrow. Cored samples of red marrow from the axial skeleton and proximal humerus were obtained postmortem from four males and two females aged 79-92 years.

Healing bone lesion defects using injectable CaSO /CaPO -TCP bone graft substitute compared to cancellous allograft bone chips in a canine model.

CaSO /CaPO -TCP bone graft substitute has been shown to be effective for treatment of bone lesion defects, but its mechanical, histological, and radiographic characteristics have not been studied in direct comparison with a conventional treatment such as cancellous allograft bone. Thirteen canines had a critical-size axial defect created bilaterally into the proximal humerus. CaSO /CaPO -TCP bone graft substitute (PRO-DENSE™, Wright Medical Technology) was injected into the defect in one humerus, and an equal volume of freeze-dried cancellous allograft bone chips was placed in the contralateral defect.

Alloy Microstructure Dictates Corrosion Modes in THA Modular Junctions.

Background: Adverse local tissue reactions (ALTRs) triggered by corrosion products from modular taper junctions are a known cause of premature THA failure. CoCrMo devices are of particular concern because cobalt ions and chromium-orthophosphates were shown to be linked to ALTRs, even in metal-on-polyethylene THAs. The most common categories of CoCrMo alloy are cast and wrought alloy, which exhibit fundamental microstructural differences in terms of grain size and hard phases.

Mechanical, chemical and biological damage modes within head-neck tapers of CoCrMo and Ti6Al4V contemporary hip replacements.

Total hip replacement (THR) failure due to mechanically assisted crevice corrosion within modular head-neck taper junctions remains a major concern. Several processes leading to the generation of detrimental corrosion products have been reported in first generation modular devices. Contemporary junctions differ in their geometries, surface finishes, and head alloy.

Adverse Local Tissue Responses to Failed Temporomandibular Joint Implants.

Purpose: The purpose of this study was to determine whether failed alloplastic temporomandibular joint replacement (TMJR) devices can elicit the aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) reaction seen in some patients with metal-on-metal hip arthroplasties.

Materials And Methods: This study involved analysis of paraffin-embedded sections of peri-implant tissue from failed TMJ implant cases obtained from 3 independent sources. Hematoxylin and eosin staining, conventional and polarized light microscopy, back-scattered electron imaging, and energy-dispersive x-ray analysis were used.

Aseptic Lymphocytic-Dominated Vasculitis-Associated Lesions Scores Do Not Correlate With Metal Ion Levels or Unreadable Synovial Fluid White Blood Cell Counts.

Background: Failed metal-on-metal (MoM) bearings are being increasingly encountered with little information to guide evaluation for aseptic lymphocytic-dominated vasculitis-associated lesions (ALVAL). It is often assumed that elevated metal ion levels correlate with the occurrence of ALVAL. Our purpose was to determine the utility of the erythrocyte sedimentation rate, C-reactive protein, synovial white blood cell count, differential (%PMN), and serum metal ion levels in diagnosing ALVAL.

Does Surface Topography Play a Role in Taper Damage in Head-neck Modular Junctions?

Background: There are increasing reports of total hip arthroplasty failure subsequent to modular taper junction corrosion. The surfaces of tapers are machined to have circumferential machining marks, resulting in a surface topography of alternating peaks and valleys on the scale of micrometers. It is unclear if the geometry of this machined surface topography influences the degree of fretting and corrosion damage present on modular taper junctions or if there are differences between modular taper junction material couples.

How Does Wear Rate Compare in Well-functioning Total Hip and Knee Replacements? A Postmortem Polyethylene Liner Study.

Background: The longevity of total hip (THR) and knee replacements (TKR) that used historical bearing materials of gamma-in-air sterilized UHMWPE was affected more by osteolysis in THRs than in TKRs, although osteolysis remains a concern in TKRs. Therefore, the study of polyethylene wear is still of interest for the knee, particularly because few studies have investigated volumetric material loss in tibial knee inserts. For this study, a unique collection of autopsy-retrieved TKR and THR components that were well-functioning at the time of retrieval was used to compare volumetric wear differences between hip and knee polyethylene components made from identical material.

Nanoscale surface modification by anodic oxidation increased bone ingrowth and reduced fibrous tissue in the porous coating of titanium-alloy femoral hip arthroplasty implants.

Hip arthroplasty femoral stems coated with Ti6Al4V beads were treated by anodic oxidation in H PO for enhanced bioactivity and were studied in a 6-month canine model to determine the effects of the treated surface on the ingrowth of bone and soft tissues. The area fractions of bone, marrow, and fibrous tissue in the porous coating of seven treated and seven untreated control implants were determined using histomorphological techniques. The area fraction of bone within the porous coating was greater for anodic oxide treated (23.

Modern trunnions are more flexible: a mechanical analysis of THA taper designs.

Background: There is renewed concern surrounding the potential for corrosion at the modular head-neck junction to cause early failure in contemporary THAs. Although taper corrosion involves a complex interplay of many factors, a previous study suggested that a decrease in flexural rigidity of the femoral trunnion may be associated with an increased likelihood of corrosion at retrieval.

Questions/purposes: By analyzing a large revision retrieval database of femoral stems released during a span of three decades, we asked: (1) how much does flexural rigidity vary among different taper designs; (2) what is the contribution of taper geometry alone to flexural rigidity of the femoral trunnion; and (3) how have flexural rigidity and taper length changed with time in this group of revised retrievals?

Methods: A dual-center retrieval analysis of 85 modular femoral stems released between 1983 and 2012 was performed, and the flexural rigidity and length of the femoral trunnions were determined.

Adverse local tissue reaction arising from corrosion at the femoral neck-body junction in a dual-taper stem with a cobalt-chromium modular neck.

Background: Femoral stems with dual-taper modularity were introduced to allow additional options for hip-center restoration independent of femoral fixation in total hip arthroplasty. Despite the increasing availability and use of these femoral stems, concerns exist about potential complications arising from the modular neck-body junction.

Methods: This was a multicenter retrospective case series of twelve hips (eleven patients) with adverse local tissue reactions secondary to corrosion at the modular neck-body junction.

Implantation of a titanium partial limb prosthesis in a white-naped crane (Grus vipio).

A female white-naped crane (Grus vipio) was presented with an open, oblique fracture of the distal right tarsometatarsus and concomitant vascular and nerve damage. Conventional fracture fixation repairs failed, which led to implantation of a custom titanium limb prosthesis. After subsequent revisions with 2 different prosthetic devices, limb function was ultimately restored but a later yolk embolism caused a circulatory compromise in the opposite leg, which necessitated euthanasia.

Successful long-term fixation and progression of osteolysis associated with first-generation cementless acetabular components retrieved post mortem.

Background: Primary cementless acetabular reconstruction has shown durable long-term fixation. Late failures secondary to aseptic loosening are rare but may occur in patients with previously well-fixed components. In the present study, the histopathological characteristics of postmortem specimens were correlated with wear damage and radiographic data in an attempt to better understand the long-term events in the periacetabular tissue around well-functioning devices.

In vivo oxide-induced stress corrosion cracking of Ti-6Al-4V in a neck-stem modular taper: Emergent behavior in a new mechanism of in vivo corrosion.

In vivo modular taper corrosion in orthopedic total joint replacements has been documented to occur for head-neck tapers, modular-body tapers, and neck-stem tapers. While the fretting corrosion mechanism by which this corrosion occurs has been described in the literature, this report shows new and as yet unreported mechanisms at play. A retrieved Ti-6Al-4V/Ti-6Al-4V neck-stem taper interface, implanted for 6 years is subjected to failure analysis to document taper corrosion processes that lead to oxide driven crack formation on the medial side of the taper.

Early failure of metal-on-metal artificial disc prostheses associated with lymphocytic reaction: diagnosis and treatment experience in four cases.

Study Design: Report of four collected cases.

Objective: The purpose of this report is to describe the presentation, diagnostic workup, treatment, and pathologic findings in four cases of lymphocytic reaction in patients receiving a metal-on-metal total disc replacement (TDR).

Summary Of Background Data: Metal-on-metal designs in hip arthroplasty have gained popularity because of decreased volumetric wear rates and theoretically increased implant longevity.

Metal-on-metal bearing surfaces.

Metal-on-metal bearing couples remain a popular option in total hip arthroplasty and are the only currently available option for surface replacement arthroplasty. In general, the intermediate-term clinical performance of metal-on-metal bearings has been favorable. There are, however, lingering concerns about the biologic consequences of metal release from these bearings in terms of both local tissue effects, including delayed-type hypersensitivity reactions in a subset of patients, and potential systemic effects as a consequence of chronic elevations in serum cobalt and chromium content.

In vivo severe corrosion and hydrogen embrittlement of retrieved modular body titanium alloy hip-implants.

Titanium alloys are widely used in total-joint replacements due to a combination of outstanding mechanical properties, biocompatibility, passivity, and corrosion resistance. Nevertheless, retrieval studies have pointed out that these materials can be subjected to localized or general corrosion in modular interfaces when mechanical abrasion of the oxide film (fretting) occurs. Modularity adds large crevice environments, which are subject to micromotion between contacting interfaces and differential aeration of the surface.

Vertebroplasty comparing injectable calcium phosphate cement compared with polymethylmethacrylate in a unique canine vertebral body large defect model.

Background Context: Vertebroplasty was developed to mechanically reinforce weakened vertebral bodies. Polymethylmethacrylate (PMMA) bone cement has been most commonly used but carries risks of thermal injury and respiratory and cardiovascular complications. Calcium phosphate (CaP) offers the potential for biological resorption and replacement with new bone, restoring vertebral body mass and height.

Modes of wear after semiconstrained total elbow arthroplasty.

Background: Osteolysis and aseptic loosening are increasingly recognized complications of total elbow arthroplasty. However, unlike the literature on total hip and knee arthroplasty, studies describing the mechanisms of these processes after total elbow arthroplasty are sparse.

Methods: Semiconstrained total elbow arthroplasty components were retrieved from sixteen elbows (fourteen patients) at either revision surgery (at a mean of five years after implantation) for mechanical failure (fifteen elbows) or postmortem examination (one elbow).

Bone ingrowth through porous titanium granulate around a femoral stem: histological assessment in a six-month canine hemiarthroplasty model.

The procedure of using of porous titanium granules for cementless fixation of a hip replacement femoral stem was studied in a hemiarthroplasty model in 10 canines for 6 months. A vibrating instrument was used to facilitate both the delivery and distribution of the irregularly shaped porous titanium granules into the femoral canal as well as the subsequent insertion of a titanium alloy stem into the intramedullary bed of granules. Histological examination revealed lamellar bone formation through the mantle of porous titanium granules in continuity with the surrounding cortex resulting in the formation of an integrated mantle of bone and titanium granulate around the prosthesis.

Implantation of the femoral stem into a bed of titanium granules using vibration: a pilot study of a new method for prosthetic fixation in 5 patients followed for up to 15 years.

This study describes a new method for the fixation of titanium hip stem prostheses based on interdigitation of irregularly shaped porous titanium granules onto bone tissue. The granules were distributed into the prepared femoral cavity using a vibrating tool, and the stem was vibrated and tapped into the bed of granules. In this pilot study, 5 patients were followed between 9 and 15 years.

Increased bone formation using calcium sulfate-calcium phosphate composite graft.

Calcium phosphates (CaPO4) and faster-resorbing calcium sulfate (CaSO4) are successfully employed as synthetic bone grafts for treatment of contained defects. We used a canine critical-sized bone defect model to study an injectable CaSO4/CaPO4 composite graft that incorporated a matrix of CaSO4 and dicalcium phosphate dihydrate into which beta-tricalcium phosphate granules were distributed. The area fraction, ultimate compressive stress, and elastic modulus of restored bone and the relative rates of material resorption were compared between the CaSO4/CaPO4 composite graft and pure CaSO4 pellets and to normal canine bone.

Effects of implant material and plate design on tendon function and morphology.

Titanium implants are an alternative to stainless steel implants for internal fixation after fracture. The advantages of titanium include decreased implant stiffness, increased bio-compatibility, and diminished stress shielding. However, titanium has been implicated in tendon irritation and adhesions when used in the hand and wrist.