Ceramic materials as bearing surfaces for total hip arthroplasty

During the past decade, advances in total hip arthroplasty component design have produced implants with reliable clinical results in regard to fixation.

The foremost unresolved challenge has been the development of bearing surfaces that can withstand the higher demands of younger and more active patients.

New alternative bearings with superior wear characteristics that minimize debris include

• ceramic-on-ceramic,
• metal-on-metal, and
• highly cross-linked polyethylenes in combination with ceramic or metal.

Alumina-on-alumina ceramic bearings are extremely hard and scratch resistant and provide superior lubrication and wear resistance compared with other bearing surfaces in clinical use.

Survivorship revision for any reason for the alumina ceramic bearings at 10 years was significantly higher compared with metal-on-polyethylene.

Bearings currently being studied because of their encouraging wear performance in the laboratory are an

• alumina matrix (82% alumina, 17% zirconia, 0.3% chromium oxide),
• zirconium oxide, and
• ceramic-on-cobalt-chromium.

Early (?) Diagnosis of Low-symptomatic Ceramic Acetabular Liner Fracture in Ceramic-on-Ceramic Total Hip Arthroplasty

"Catastrophic" failure of one-piece ceramic liner without major trauma in a very active and heavy patient also having controlateral hip disease and right total knee arthroplasty (asymetric squatting) AND right shoulder arthroplasty for advanced omarthosis with normal rotator cuff (sugar cane handpicking ?)

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 mainly 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 still seems a rare complication.

Trauma, high activity level, and obesity may increase the risk of fracture.

Defective ceramic manufacture, inadequate (sandwich with polyethylene) implant design, and errors in surgical technique may contribute to breakage.

Rather than Caucasian, Asian (by extension West Indian) population lifestyle, including squatting, kneeling, and possibly sitting cross-legged, has been correlated to liner rim impingement and fracture.

Additional reports concerning failure of various, mainly sandwich, but not exclusively, ceramic liners have recently been described.

I will describe here a unique case of apparently early diagnosis of a low-symptomatic fracture of an Anca-Fit acetabular liner occurring 3 years after implantation of an uncemented ceramic-on-ceramic modular THA.

Perioperative complications in hip revision surgery

I conducted a retrospective study to assess morbidity and mortality in patients undergoing revision total hip arthroplasty (THA) procedures.

There are many complications some of these leading to new revisions.

About half are related to the surgical procedure (dislocation, femoral fracture, infection…).

Life-threatening complications (4 %) ended in patient death in 1 % of the cases.

Complications are more frequent in patients with an ASA score = 3 or aged over 75 years..

Age as well as inexperimented anesthesia or assistance are also predictive of femoral misalignment and fracture.

Dislocations are observed more frequently in patients who had undergone more than 2 procedures prior to the revision.

However 5% of dislocations in patients undergoing a first revision procedure and 15% in the others seems really  too much.

In addition, perioperative blood loss (even with EPO preparation) and duration of the procedure are greater in case of bipolar replacement than for isolated acetabular replacement.

Our experience and data in the literature point to the important age factor in the development of complications.

Preservation of a well-fixed femoral component does not appear to worsen prognosis and leads to fewer complications than bipolar changes.

The decision to revise a THA must take into consideration the functional impairment but also the risks inherent in revision procedures, particularly in old patients who have undergone several procedures.

Revising the acetabular component alone can be an interesting option if the femoral component remains well-fixed although our follow-up is insufficient to determine whether this attitude provides better long-term outcome than complete bipolar revision.

Better patient selection and improved operative technique, in particular in femur preparation, should help reduce morbidity and mortality in this type of procedure.