Ceramic Acetabular Liner Research Articles

AB159. SOH23ABS_230. Case presentation: atraumatic fracture of revised ceramic femoral head in articulation with ceramic acetabular liner

AB159. SOH23ABS_230. Case presentation: atraumatic fracture of revised ceramic femoral head in articulation with ceramic acetabular liner

Spontaneous resolution of asymptomatic alumina matrix composite ceramic liner dissociation: a case report

BackgroundTotal hip arthroplasty(THA)is widely used to treat end-stage hip disorders. Ceramic-on-ceramic total hip prostheses are widely used because of their durability. Alumina matrix composite (AMC), known as the fourth-generation ceramics, reduces implant fracture and wear rate compared to their predecessors. However, ceramic acetabular liner dissociation is a complication that necessitates revision of the AMC prostheses. To date, only few cases of AMC liner dissociation have been reported and all of which have been treated with revision surgery. Therefore, the prognosis of non-operated AMC liner dissociation remains unknown so far.Case presentationA 57-year-old man with avascular necrosis of the femoral head was treated with THA, wherein a Pinnacle® (DePuy, J&J, Warsaw, IN) acetabular cup and AMC liner were implanted. Intraoperative examination confirmed proper seating of the liner, whereas the initial postoperative radiograph revealed liner dissociation. The patient refused surgical revision due to the absence of symptoms and was discharged and followed-up. The patient made an uneventful recovery, and radiographic follow-up at 6-month post-operation showed that the liner was re-seated to its right position. No clinical or radiographic anomaly was found at the 15-month of postoperative follow-up.ConclusionsHere, we report an unprecedented case of AMC ceramic liner dissociation with spontaneous resolution. This case shows that ceramic liner dissociation could be asymptomatic, and careful postoperative examination of the patient is important. Spontaneous resolution is possible, but the underlying mechanism and the eligible patient to benefit from it must be investigated. Before clarifying these questions, revision surgery should be the first-line treatment.

Bearing Surfaces for Total Hip Arthroplasty.

Metal-on-highly cross-linked polyethylene is considered the preferred bearing surface for conventional total hip arthroplasty because of its safety profile and excellent results in the first 10 to 15 years of use. However, with younger patient age, activity expectations increase, and the life expectancy of patients with total hip arthroplasty also has increased, so interest remains in other bearing couples. These other options include the use of various ceramic composites for the femoral head on highly cross-linked polyethylene, the so-called second-generation antioxidant polyethylenes, and ceramic acetabular liners. Several of these bearing couples have shown excellent wear rates in vitro, and short-term clinical studies have demonstrated favorable wear and safety results. It is uncertain whether any of these bearing couples should be adopted at present. Understanding the unique properties and possible complications of these bearing couples is critical for appropriate implant selection.

Metallosis after Exchange of the Femoral Head and Liner following Ceramic Acetabular Liner Dissociation in Total Hip Arthroplasty with a Modular Layered Acetabular Component

The type of bearing material that should be used in revision surgery after the failure of ceramic-on-ceramic total hip arthroplasty (THA) remains controversial. In the case of ceramic fracture, the residual ceramic particles can cause consequent metallosis when metal implants are used for revision THA. On the other hand, in the case of THA failure without ceramic fracture, revision THA with a metal femoral head provides satisfactory results. We report an unusual case of progressive osteolysis due to metallosis that developed after revision THA for ceramic liner dissociation without a liner fracture performed using a metal femoral head and polyethylene liner. The residual metal debris and abnormal pumping motion of the polyethylene liner due to the breakage of the locking system or the aspherical metal shell being abraded by the ceramic head seemed to be the cause of the progressive osteolysis.

A Novel Technique for Identification of Fractured Ceramic Acetabular Liner in Total Hip Arthroplasty: A Case Report

In total hip arthroplasty ceramic bearings are liable to fracture. We present the case of an 82-year-old male with groin pain and an audible squeak 6 months post ceramic on ceramic hip arthroplasty. Initial plain radiography and examination under anaesthetic (EUA) were normal. Fluoroscopy with normal image exposure was also unremarkable. Over penetration of the image intensifier film demonstrated a fracture of the ceramic acetabular liner. The patient subsequently underwent a revision of both acetabular and femoral bearing surfaces.Displaced ceramic liner fractures are easy to identify with plain radiographs. We recommend the use of over penetration using image intensification as a technique to help identify subtle ceramic liner fractures. To our knowledge this has not been previously reported in the literature.

Extraction of a well fixed but fractured ceramic acetabular liner.

Ceramic fractures have been reported to occur in hip replacements, but the techniques used to extract a well fixed but fractured component are not commonly described. We present a case of ceramic liner fracture and validate a modification of a previously reported extraction technique that allowed us to save the acetabular cup and insert a polyethylene liner. With an increasing trend in ceramic bearing usage, it is likely that the number of ceramic liner fractures will increase and therefore knowledge of successful extraction techniques will be desirable.

New method for determining in vitro structure stiffness of ceramic acetabular liners under different impact conditions

Increasing both patient mobility and prosthesis life span requires improvements in the range of motion and wear behavior of the liner. With the use of new composite alumina–zirconia ceramic materials, the same stability of the liner can be achieved at lower wall thickness than it is possible with alumina-only materials. The aim of this study was developing a method for determining the in vitro structure stiffness of ceramic acetabular liners against impact stresses. The first trials were performed with a common alumina acetabular liner type (Ceramtec; Biolox forte; diameter 28mm; thickness 7mm) and a new type of alumina–zirconia (Ceramtec Biolox delta; same dimensions) liner. The clinically established alumina liner was reproducibly damaged using worst case Separation/subluxation equivalent to one-fourth or half of the head diameter, and an impact load of 15J. The liners containing the new alumina–zirconia material were not damaged in any of the trials up to an impact load of 20J and half head diameter offset.

Thin Hard Crest on the Edge of Ceramic Acetabular Liners Accelerates Wear in Edge Loading

Ceramic acetabular liners may exhibit a small, sharp crest—an artifact of discontinuous machining steps—at the junction between the concave spherical surface and the interior edge. On 3 ceramic liners, this crest was found to form a 9° to 11° deviation from tangency. Edge loading wear tests were conducted directly on this crest and on a smoother region of the edge. The crest elicited 2 to 15 times greater volumetric wear on the femoral head. The propensity of the crest to rapidly (<2000 wear cycles) cause elevated wear under low contact force (200 N) suggests that the crest artifact of prevailing machining protocols might be a root cause of stripe wear and squeaking in ceramic acetabular bearings.

Acetabular Screw Head-induced Ceramic Acetabular Liner Fracture in Cementless Ceramic-on-Ceramic Total Hip Arthroplasty

Ceramic liner fractures are rare after ceramic-on-ceramic THA. This article describes a case of an early ceramic liner fracture caused by impingement with a tilted acetabular screw head 2 months after cementless ceramic-on-ceramic THA. A 59-year-old man underwent primary THA for avascular necrosis of his right femoral head. The implant used was an Osteonics Secur-Fit HA ceramic-on-ceramic bearing system. The metal shell was fixed with 1 cancellous bone screw. During the index procedure, the acetabular screw seemed tilted in the metal shell hole, but the liner was fully seated in the metal shell without difficulty. However, 2 months later he re-presented due to pain and crepitation in the right hip. Radiographs showed that the ceramic acetabular insert had fractured. At revision, ceramic insert had fractured into large and numerous comminuted fragments, and the acetabular screw head was slightly tilted and protruded over the inner surface of the metal shell, which had worn eccentrically. The ceramic inner head and metal shell were visibly intact. Because the metal shell-bone fixation was firm, a new identical design ceramic liner and head were fitted, and no adverse event has occurred since. This case suggests that a complete check of the inside of the shell should be made when using an acetabular screw and ceramic liner. In particular, the screw head must not be tilted or left proud of the inside surface of the shell. Correct acetabular screw direction and seating are essential to avoid detrimental clinical consequences.

Delayed Diagnosis of Low-Symptomatic Ceramic Acetabular Liner Fracture in Ceramic-on-Ceramic Total Hip Arthroplasty

Alumina ceramics in total hip arthroplasty (THA) have been used in Europe since 1970. Over the years, ceramic-on-ceramic coupling became a valid option in THA because of excellent biocompatibility and tribological properties. The major disadvantages are possible squeaking and risk of breakage, usually disclosed by pain and functional impairment. Squeaking is an audible noise arising from ceramic-on-ceramic bearings, the incidence of which is reported to range from 1% to 7% of THAs. Component positioning, stripe wear, and edge loading have all been implicated. Clicking sounds and scratching have also been anecdotally described. Breakage of a ceramic component due to brittleness of the material is a rare complication. Trauma, high activity level, and obesity may increase the risk of fracture. Defective ceramic manufacture, inadequate implant design, and errors in surgical technique may contribute to breakage. Asian population lifestyle, including squatting, kneeling, and sitting cross-legged, has been correlated to liner rim impingement and fracture. Additional reports concerning failure of various ceramic liners have recently been described.

Fracture of a ceramic liner in a total hip arthroplasty with a sandwich cup

Alumina ceramic-on-ceramic total hip arthroplasty (THA) has been widely used due to its advantages such as low wear, scratch resistance, wettable surface and relatively low biological reactivity of the wear particles. Nevertheless, this material in THA still persists to be one of the major concerns about the risk of fracture, due to its brittleness. Many authors have reported a fracture of the ceramic head but few reported a fracture of the ceramic acetabular insert. In order to reduce the rigidity of the ceramic-on-ceramic coupling and prevent an impingement between the rim of the ceramic liner and the metal neck of the femoral stem, a modular acetabular component with a sandwich insertion (alumina/polyethylene/titanium) was proposed. We report the fracture of the ceramic acetabular liner of such a ceramic sandwich cup due to a slightly retroverted position of the cup that causes an impingement between the femoral stem and the rim of the insert. The fracture occurred 3 years after the operation without trauma. At revision the entire cup was replaced using a polyethylene liner without inner ceramic liner.

Mechanical performance of ceramic acetabular liners under impact conditions

Although new generation alumina ceramics have exhibited a reduced incidence of fracture, concern still persists about the behavior of ceramic acetabular liners under impact conditions. The objective of this study was to explore whether fracture of a new generation alumina ceramic liner was likely to occur in vivo. Ceramic liners were impacted with forces of 23, 21, 15, and 12 kN (n = 3 at each force). At 23 kN, all 3 ceramic liners fractured on the first impact; at 12 kN none of the ceramic liners fractured after 20 impacts. The threshold force of 12 kN is large in comparison with estimated physiologic forces on the hip during falls or stumbling, suggesting that ceramic liner fracture is not a definite consequence of liner impact.

Ceramic acetabular liner fracture in total hip arthroplasty with a ceramic sandwich cup

In total hip arthroplasty, a modular acetabular component with a sandwich insertion (alumina ceramics/polyethylene/titanium) was proposed. The polyethylene layer might reduce the rigidity of the ceramics and prevent an impingement between the ceramic liner rim and the femoral neck. A case of an acetabular liner fracture of the ceramic sandwich cup was presented. The fracture occurred 1.4 years after the operation without trauma. Because the ceramic liner rim was hit by the head following the impingement between the neck and the polyethylene, the cause of the fracture might be the stress concentration at the rim of the ceramic liner, of which the thickness was only 4 mm. At revision surgery, the fractured ceramic liner was replaced with a polyethylene liner without inner ceramic liner.