FH Orthopedics

ESOP is a range of cementless femoral stems that are anatomical and modular, available in 10 sizes of metaphysis for each side as well as a range of 7 diaphyses. This wide range of implants thus allows surgeons to propose, during the peri-operative period, a combination of 70 possibilities for each side.
This principle of adapting the prosthesis to the morphology of the patient’s femur, rather than the opposite, is called “morphoadaptation”.

After validating the excellent results obtained with this prosthesis, and after almost 20 years of clinical follow-up, we have modified this prosthesis so as to adapt it to LIS (Less Invasive Surgery), with a range of 3 diaphyseal pegs, thus increasing the morphoadaptation to 80 possibilities for each side.

The set of instruments provided with this femoral prosthesis is simple, precise and satisfies the various requirements in terms of LIS approach, be it anterior, posterior, anteroexternal…

Indications

This range of femoral stems is adapted to first intention hip operations following coxarthrosis or a fracture of the neck of the femur, as well as for intermediate hip prosthesis surgery or finally in cases of simple revision that does not require a long or locked femoral stem :

• Coxarthrosis, first intention THA ;
  
• Fracture of the neck of the femur as intermediate hip prosthesis ;
  
• Simple revision.

The concept

The concept of the ESOP femoral stem was developed in 1991 to adapt the femoral stem to the morphology of the patient’s bone.

This stem is composed of 2 elements:

• A tulip-shaped metaphyseal part, guaranteeing adherence and maximum metaphyseal filling, plus an HAP coating for better secondary fixation.
• A diaphyseal part made of anodised titanium to prevent any bone adherence, and guaranteeing that the femoral prosthesis is guided and oriented perfectly.
  

Product characteristics

The ESOP femoral stem is made from a TA6V ELI titanium alloy in 2 parts:

• The metaphyseal range comes in 10 left sizes and 10 right sizes, from sizes 5 to 20, with a hydroxyapatite coating,
• The lengths of the necks and offsets are homothetic, depending on the different sizes,
• The cylindrical neck is a 12/14 neck that makes it possible to use alumina femoral heads, with a cervicodiaphyseal angle of 135°.

The range of diaphyses is also made from a titanium alloy, but anodised so there is no adherence at this level of the femur.
This range is composed of 7 sizes of standard diaphysis, with diameters from 9 to 15 mm, completed by 3 sizes of diaphyseal pegs that are more adapted to LIS surgery.

Bibliography

RESULTS OF HYDROXYAPATITE-COATED MODULAR FEMORAL STEM IN PRIMARY TOTAL HIP ARTHROPLASTY. A MINIMUM 5-YEARS FOLLOW UP.

The Journal of Arthroplasty Vol. 23 No. 8 2008
0883-5403/08/2308-0007$34.00/0
DOI:10.1016/j.arth.2007.10.012

Eduardo GARCIA-REY, MD, PhD, Teresa MUNOZ, MD, Jorge MONTEJO, MD, and Javier MARTINEZ, MD

 

Abstract: The use of a modular metaphyseal-diaphyseal femoral stem in primary total hip arthroplasty is infrequent. We analyze 94 ESOP (Fournitures Hospitalieres, Heimsbrunn, France) cementless 2-piece modular stems after a minimum 5 years of follow-up. There were 2 aseptic femoral stem loosenings and no cases with thigh pain. Mean femoral canal filling was 90%. Radiographic ingrowth was obtained in 83 (P b .001). At 7 years, the survival rate for femoral aseptic loosening was 97.8% and no stem was at risk for revision (95% confidence interval, 94.8%-100%). This prosthesis provides good clinical results with absence of pain and excellent radiographic results. It is an option in femora with good bone quality. Femoral osteopenia and cortical widening were infrequent, and the modular metaphyseal-diaphyseal junction was not a problem in vivo. Key words: primary total hip arthroplasty, femoral stem, hydroxyapatite.

HYDROXYAPATITE-COATED ESOP MODULAR FEMORAL STEM : 3 TO 10 YEARS OUTCOME IN 155 CASES

Revue de chirurgie orthopédique
2007. 93. 247-254

S. NAUDI, N. MEDHI, G. DAUPLAT, V.STAQUET, H. MESTDAGH, C. MAYNOU

 

Abstract: Purpose of the study: primary and secondary stability of the ESOP prosthesis depends exclusively on cementless metaphyseal anchoring. This modular implant is composed of an hydroxyapatite6coated metaphysic on which a diaphyseal piece is added intraoperatively simply to act as a centering device. The prupose of this retrospective analysis of a consecutive series was to assess primary and secondary stability of the ESOP implant by measuring axial migration over the time.

Material and methods: Between 1995 and 2001, 172 primary total hip arthroplasties (THAs) were performed with the ESOP femoral implant and the ATLAS III acetabular implant. Six patients lost to follow-up and eleven patients who died were excluded from the analysis.

The review thus concerned 155 THA in 128 patients (66woment and 32 men), mean age 57 years (age range 28-77), 53% with an occupational activity at the time of surgery. Degenerative hip disease and aseptic osteonecrosis were present in 87% patients. Imagika, a dedicated software, was used to measure axial migration and overall of the offset of the THA at four distinct times: on the immediate pre- and postoperative films, after introduction of weight-bearing, and at last follow-up (mean 61 months, range 35-114 months). Survival and clinical and radiographic outcome were also assessed with the Postel-Merle-d’Aubigné (PMA) score.

Results: THA survival was 98%, all causes of failure included. The PMA score showed 97% excellent, very good and good outcome. Axial migration greater than 5mm was demonstrated in ten hips (6,4%). Among these ten, seven exhibited migration during the first month than did not move further up to last follow-up. Comparison between the pre- and postoperative images revealed a 10mm reduction in offset in 38% of hips, showing that the hip rotation center was medialized.

Discussion: migration observed in ten implants corresponded to restabilization at weight-bearing in seven. There was correlation with the clinical outcome or poor radiological osteointegration.

Conclusion: primary and secondary stabilization of the ESOP implant is satisfactory in the series, the rotation center of the hip was globally medialized so that it would be useful to have available lateralized implants.

THE ESOP-HA MODULAR CEMENTLESS FEMORAL STEM
A study of the results of 165 hip arthroplasties with a minimum 10-year follow-up

Eur J Orthop Surg Traumatol (2005) 15: 275-285
DOI 10.1007/s00590-005-0002-y

Michel P. PHILIPPE, Elvira MARTIN, Jacques HUMMER, Gérard GACON, Alain DAMBREVILLE, André RAY

 

Abstract: The authors report on more than 10 years’ experience of using a cementless femoral stem, with a two-piece modular design, for indications of primary prosthetic replacement.  165 prostheses, inserted between 06/11/1991 and 31/12/1994, were reviewed in 2004. No patient was lost to follow-up. The probability of 10-year survival of these hip prostheses was assessed using the actuarial Kaplan-Meier method (the endpoint was revision of the arthroplasty regardless of the reason: failure of the femoral or acetabular component, fracture of one piece of the implant etc.). Fourteen patients were died for other reason that prosthesis. The mean age of the 165 patients (84 women, 81 men) was 64 years. The clinical results were excellent or good in 87.2 % of hips. There was no instance of post-operative thigh pain (apart from one case), because of the primary stability of the hydroxyapatite-coated metaphyseal part where stress transmission occurs, while the diaphyseal part, selected in accordance with requirements and smaller in diameter than the femoral canal, remained free in the diaphysis. No significant difference in the results was noted in accordance with the pattern of femoral anatomy encountered; however, the cylindrical femur yielded a slightly inferior result (PMA score). Radiological follow-up showed that femoral fixation had been obtained, generally accompanied by obvious signs of bone fixation (endosteal ossification, radiolucencies indicating condensed bone in the smooth zone). A high number of cortical changes was not noted. Two stems were the cause of revision surgery, one because of thigh pain without sealing, the other because the stem fractured. Six acetabular implants were removed without interfering with the femoral stem, because of localised osteolysis around an expandable peg. Two other acetabular implants were replaced: one because poor positioning resulted in recurrent luxation and the other for premature wear of the polyethylene after seven years.

The grounds for revision were failure of the acetabular implant in 8 cases out of 10.

Thus there is sufficient justification for the use of this modular 2-piece stem, which has fulfilled its purpose in the majority of patients, enabling us to extend with confidence indications for the cementless stem to all the anatomical types of femur encountered. Our series of patients included almost 78.7 % of what are known as “standard” femurs, but in the remaining cases (21.3 %) or in more than one in five instances, the modular stem made it possible to extend the indications for a cementless prosthesis to all the patterns of femur encountered, in particular to young adults with femoral dysplasia or a cylindrical femur.

The survival curve reflects the life of the implant: implant survival is 96.3 %. If acetabular revisions are not included it is 98.8%.

conclusions:  A modular system then, consisting of a metaphyseal and diaphyseal part, appears to be a first-rate component which optimizes the indication for implantation of a cementless femoral prosthesis in order to obtain the correct performance of a medical service as the survival curve demonstrates.

MODULARITE METAPHYSO-DIAPHYSAIRE ET TIGES FEMORALS SANS CIMENT

Revue de chirurgie orthopédique
2001, 87, 331-339

G.GACON, M-P.PHILIPPE, A.RAY, J.HUMMER, H.HOURLIER, A.DAMBREVILLE

 

Abstract : Purpose of the study: we assessed outcome after total hip arthroplasty (THA) using a dual metaphyseal-diaphyseal modular femoral stem with hydroxyapatite coating on the metaphyseal portion only. Implanted without cement, this stem was adaptable to all the anatomic morphotypes defined by the Noble canal flare index.

Material and methods: THA was performed in 116 patients (124 hips), mainly for degenerative joint disease (80% for dysplasia). Mean age was 61,2 years. Follow up was 6,9 years (72-108 months).

Results: there were no preoperative complications excepting 3 cases of neck fissuration without clinical consequence. There was no trochanteric fracture. We had two early and one late dislocations. The Postel Merle d’Aubigne score improved from 8,09 to 17,27. Clinical outcome was not influenced by patient age, weight, or morphotype. Radiologically, signs of bone ingrowth were found in more than 80% of the cases. Lucent lines were seen in only 3 cases. There was a single case of migration. No revision was needed among the cases with ossifications (23%, 22% Brooker I) and no femur revisions were required. There was no mechanical problem involving the metaphyseal-epiphyseal junction.

Discussion: the dual metaphyseal-diaphyseal modular stem was found to be safe and effective implant adaptable to all anatomic variations of the femur and providing good primary stability. In our series, 58% of the femurs were “standard” but for one-third of the femurs, the modular stem enabled implantation without cement, particularly in young adults with a dysplasic or funnel-shaped femur.

Conclusion: the dual metaphyseal-diaphyseal modular stem was found to be most useful for optimizing total hip arthoplasty without cement.