Metallic Modular Taper Junctions in Total Hip Arthroplasty

The emergence of modularity in total hip arthroplasty (THA) in the 1980s and 1990s was based on the fact that the benefit of these design features outweighed the risk. The use of metallic modular junctions presents a unique set of advantages and problems for use in THA. The advantages include improvement in fit and fill of the implant to bone, restoration of joint mechanics, reduced complications in revision surgery and reduction of costly inventory. However, the risks or concerns are a little harder to identify and deal with. Certainly corrosion, and fatigue failure are the two most prevalent concerns but now the specifics of fretting wear and corrosive wear increasing particulate debris and the potential biological response is having an impact on the design and potential longevity of the reconstructed hip. Material and designs are facing a shorter life expectancy than what was previously thought, mostly due to an increasing level of physical activity by the patient. Because there are no accurate laboratory test whereby the service life and performance of these implants can be predicted, early controlled clinical evaluations are necessary. Early publication of testing and clinical impressions should be encouraged in an attempt to reduce exposure to potential at risk patients, implants and material. The reduction and possible elimination of risks will require a balancing of all the variables requiring a multidisciplinary endeavor.This paper is designed to review the risk factors, and benefits of modular junctions in total hip arthroplasty (THA). Also some basic engineering principals that can reduce risk factors and improve functionality of modular junctions.

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Modular Head Mismatch in THA

Reconstructive Review ◽

10.15438/rr.5.4.128 ◽

2015 ◽

Vol 5 (4) ◽

Author(s):

Timothy McTighe

Keyword(s):

Femoral Head ◽

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Biological Response ◽

Office Visit ◽

Direct Anterior Approach ◽

Fretting Wear ◽

Total Hip ◽

Ceramic Femoral Head ◽

Ceramic On Ceramic

Modular femoral heads have been used successfully since the mid-1980s in total hip arthroplasty. The use of metallic modular junctions presents a unique set of advantages and problems for use in total hip arthroplasty (THA). The separation of the head from the stem by a Morse taper has provided many benefits on the precision and balancing the reconstructed joint. Historically few complications have been reported for the modular Morse taper connection between the femoral head and trunnion of the stem in metal-on-polyethylene bearings. However, the risks or concerns are a little harder to identify and deal with. Certainly corrosion, and fatigue failure are the two most prevalent concerns but now the specifics of fretting wear and corrosive wear increasing particulate debris and the potential biological response is having an impact on the design and potential longevity of the reconstructed hip. This paper is dealing with a simpler consequence of head/stem modularity. Modular head mismatch to the socket bearing articulation.Two patients by two different surgeons at two different hospitals underwent cementless THA. Both patients were female and both presented with degenerative changes to the hip articulation. Both patients underwent hip replacement via a direct anterior approach using a standard hemispherical porous coated shell. One patient had a ceramic on ceramic bearing and the other had a ceramic head on a polyethylene liner. Both patients had a 32 mm inside diameter liner implanted and both had a 36 mm ceramic femoral head. The ceramic on ceramic mismatch was not recognized until the second office visit at eight weeks. The ceramic poly mismatch was not recognized until first office visit at six weeks. Both underwent correction surgery.These two cases demonstrate human mistakes can be made and steps need to be established to prevent future mistakes of this nature.

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Epidemiological Study of Femoral Head Osteonecrosis

Revista de Chimie ◽

10.37358/rc.17.5.5593 ◽

2017 ◽

Vol 68 (5) ◽

pp. 974-976

Author(s):

Alexandru Patrascu ◽

Liliana Savin ◽

Dan Mihailescu ◽

Victor Grigorescu ◽

carmen Grierosu ◽

...

Keyword(s):

Risk Factors ◽

Femoral Head ◽

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Young Patients ◽

Head Group ◽

Bipolar Hemiarthroplasty ◽

Aseptic Necrosis ◽

Total Hip ◽

Femoral Head Osteonecrosis

In recent years, there has been an increase in the number of studies on the etiology of femoral head necrosis. We retrospectively reviewed all patients diagnosed with aseptic necrosis of the femoral in the period of 2010-2015. We recorded a total of 230 cases diagnosed with aseptic necrosis of the femoral head, group was composed of 65.7% men and 34.3% women, risk factors identified was 19.13% (post-traumatic), 13.91% (glucocorticoids), 26.52% (alcohol), 3.47% (another cause) and in 36 95% of the cases no risk factors were found. The results of the study based on the type of surgery performed on the basis of stages of disease progression, 8 patients (3.48%) benefited from osteotomy, 28 patients (12.17%) benefited of bipolar hemiarthroplasty prosthesis and 188 patients (81.74%) benefited of total hip arthroplasty. Osteonecrosis of the femoral head is characteristic to young patients between the age of 30-50 years old. Predisposing factors, alcohol and corticosteroid therapy remains an important cause of the disease. Total hip arthroplasty remains the best option for the patients with osteonecrosis of the femoral head.

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