Introduction

By its principle the patching of the hip is tempting. The large diameter of the head approaches the anatomy and makes it possible to limit the risk of luxation. The initial offset of the hip is preserved as well as the length of the neck leaving at the muscles their initial voltage! The osseous capital is preserved not only by preserving the center of the head and the neck but also by avoiding an useless deterioration of the métaphyso-diaphyseal area of the upper end of the femur. A priori the functional result should be good, the durability should depend on the quality of the installation and of the couple of friction, the resumption of arthroplasty should be simplified. (Figure 1)

In practice the clarification of this type of prosthesis was the fruit many gropings. The arthroplasty by a femoral cup was proposed before that of the prosthetic stem by in 1923. Many authors between 1923 and 1970 tried to improve the simple cup of which most known are in 1952, in 1958, in 1960 and Gerard in 1969. The technique of the simple cup was at the origin of a certain number of encouraging successes with a survival at 15 years of more than half of the cases (at one time when that of the joint replacements with pivot was even more disappointing) and of early failures due mainly to a rocker of the cup, a hull slamming of the femoral head or pains of origin .

The idea to carry out a total patching of the hip was put forward as of end of the year 60. A certain number of models were proposed throughout the Seventies which except for those of and Gerard (metal/metal) were prostheses with couple of friction metal/polyethylene: , ⁽¹¹⁾   (Figure   2), , Wagner ⁽²⁷⁾, in Europe and ⁽³⁾ in the USA. The quality of the short-term functional results and the dynamism of the designers caused a true passion for this technique ⁽¹⁹⁾; however a certain number of insufficiencies directly related to the design of the hardware were at the origin of a great number of early unsealings which led the designers themselves to give up it; the judgment of the total patching of the hip was signed in France at the time of the 1985. Mac in 4991 95 and in 7985 1 , proposed a prosthesis with a couple of friction metal/metal, an uncemented cup in close made with a negotiable instrument of surface sanded and a cemented femoral cup. Series of clinical follow-up with a hardware and an identical technique showed results favorable with a rate of unsealings and complications superposable to that of the arthroplasties with pivot.

Currently the patching of the hip is used largely in England in Canada and Belgium, regularly in Switzerland in Germany in Spain in the USA, very little in France. This return of the patching is it justified? A certain number of arguments go in this direction:

Figure 1: Total patching of the hip.

Figure 2: The patching of metal polyethylene.

1. The hardware evolved/moved

1.1. The couple of friction

The prostheses of patching currently posed have a whole a   couple   of   hard/hard friction, metal/metal (Figure 3). Progress of tribology and the precision of the modern machine tools make it possible today to carry out arthroplasties with heads of large diameter whose attrition rate is very weak and the size of the remains salted out lower than one micron what allows their transport by the macrophages ⁽¹⁰⁾. The femoral cups of patching and the adaptable heads of large diameter on femoral stems are with identical parts . The evaluation of this couple of friction can thus be done on great series of total prostheses of hip with pivot or patching. In the event of early complications on the level of the cup of patching it is possible to carry out only one unipolar recovery; the very low attrition rate of these couples metal metal with very a concept of grinding, makes it possible to hope that a late recovery could also be only unipolar.

1.2. The implant

It is about a single part whose walls are in the majority of the models m thickness. They are all the cases of the uncemented parts in whose face in contact with the bone is covered with a titanium projection whose granulation and thickness are variable.

1.3. The femoral implant

The   current femoral cups   recover only gristly surface without encroaching on the neck in order to limit its and to avoid harmful conflicts former or posterior. They are proposed in many sizes all one or two millimetres in order to approach the original size of the head as much as possible. They are fitted with a stem of small size which the effectiveness on the distribution of the stresses on the level of the neck remains very discussed. It seems however that this stem facilitates the installation of the cup and makes it possible to evaluate the postoperative right direction of the prosthesis as well as possible a   micro   mobility. All the cups are currently cemented what makes it possible to obtain from the start a perfect stability and to compensate for the irregularity of surface of certain femoral heads     in particular within the framework of necrose.

Figure 3: Modern patching metal/metal cup cement, close made.

2. The procedure can be simplified

2.1. Guideline of the cup

It is about one of difficult times of the procedure. Indeed a bad guideline of the cup produces abnormal stresses on the neck sources of rupture and the conflicts of the neck with the walls or prosthetic. These conflicts are at the origin of a rehandling with notch of the neck compared to the area of conflict. The released particles are however organic osseous particles which are not at the origin of a . A certain amendment of the neck to the conflict remains possible ⁽⁷⁾. One needs that the cup is located in the sagittal plan preferably at the center of the neck and in the frontal plane in neutral position or valgus, by avoiding the which is source of too important stresses ⁽⁶⁾.

For directing well the cup of many more or less complex systems of sighting are proposed. The endo-articular systems of variable conceptions require all good a vision of the head and a broad exhibition of the neck source of ⁽¹⁵⁾ (Figure 4). The navigation of the hip is more reliable; the capture of the various points required however always a broad exhibition of the neck ⁽²²⁾ (Figure 5). We propose   a simple technical   which consists in positioning before the realization of the channel initially a pin of the trochanter towards the head under control of an image intensifier ⁽⁸⁾ (Figure 6 and 7). It is thus possible to choose on a case-by-case basis the good position, the cup with a very fast learning curve. The technique guided by pin makes it possible to use more easily of the invasive initially minimal channels.

2.2. The channel initially

Conservation of the head and the neck which the exhibition of the , as well as the exhibition of the neck to position the cup result in carrying out most of the time initially enlarged channels which they are posterior, former with   or   according to ⁽¹⁷⁾. The French schools propose former invasive channels minimal (/) or side ( ⁽⁸⁾) (Figure 8).

Figure 4: Endo-articular systems of sighting.

Figure 5: Sighting by navigation.

Figure 6: Sighting guided by amplifier.

Figure 7: The cup is located at the center of the neck

Figure 8: Invasive minimal channel .

3. The indications and against indications are well tallied

The counter-indications of the patching of the hip are directly related on the ground, the quality of the bone and morphology the hip.

3.1. the ground

The functional results of the main series are good ⁽²⁰⁾. They are however not higher for quality of life, for the resumption of an sports activity, the amplitude of articular mobilities   to the results obtained with the prostheses with famous persons ⁽²¹⁾ (Figure 9). The main interest to carry out a patching the hip is thus the safeguarding of the osseous capital. This type of prostheses is addressed consequently on subjects which have a good life expectancy and an high level of activity; a priori dynamic subjects of less than 60 years.

In addition the molybdenum and cobalt, chromium salting out could, although that was not proven, have an harmful effect at the insufficient renal one; the problem of the realization of a prosthesis of which a party is metal (couple metal/metal   but   also metal/polyethylene   with   the hip or the knee) remains posed at the woman in age of reproduction ⁽²⁶⁾.

3.2. The quality of the bone

The most dreaded complication,   specific   with the patching the hip, is the fracture of the neck ⁽¹⁶⁾ (Figure 10). The various publications bring back a going adjustable-rate of fractures from 0,25% to 3%. They are often early (in 50 to 75% of the cases before one year) ⁽⁵⁾.

They are three times more frequent among women and four times more frequent at the obese ones ⁽¹⁴⁾.

They are also directly related to the local state of the bone: necrose wide of more than 50%, polycystic osteoarthritides, inflammatory synovitis.

Finally the operational gesture itself can cause fracture, femoral cup in or realization of a notch at the upper part of the neck due to the passage of the cylindrical bit if the prosthesis is positioned too much in valgus ⁽¹³⁾.

3.3. Architectural defect of the hip

The nondeformable part must be put in close made. An insufficiency of too important hedging   can   be   a counter-indication ⁽⁴⁾ (Figure 11). In the same way on the level of the femur a directional disorder of the neck forwards or backwards could not be corrected by a patching. In the same way a neck of short related to significant injuries of the head or a could not be corrected by a patching whose maximum correction is about isters (Figure 12)

3.4. In synthesis,

the ideal ground is a still young man with an osseous good quality dynamic which has a osteoarthritis generally which had with a (Figure 13 and 14) or one necroses of a volume lower than 50%. The absolute counter-indication is a woman of more than 60 years obese.

Figure 9: Total patching/Stem and famous person.

Figure 10: Fracture neck on: fragile bone (dialyzed = against indication)

Figure 11: Against indication: nonretentive.

Figure 12: Against indication: short neck, very .

Figure 13: 35 Years, osteoarthritis on .

Figure 14: Patching with correction of the malalignment of the head.

4. Where is the problem?

If a certain number of arguments are in favor of the patching of the hip, it persists a certain number of brakes to the realization of this technique:

* The couple of friction is a couple metal/metal; all the publications show that there exists a salting out of chromium and cobalt metal particles in particular; cobalt is urinated, chromium can be stored on the level of the liver ^{(25, 26)}. The carcinogenic risk of these particles   has   never   shown; in practice the prostheses with couple metal polyethylene used largely for more than 40 years have also released from the cobalt and chromium particles in particular the arthroplasties of knee ⁽¹²⁾; dental leadings are sources of one of greater release of material particles of the same type as joint prostheses in particular when that leads are located in opposite or when there exists a metal crown; relation of cause and effect between the existence of a joint prosthesis and a forever shown primary neoplasm. The teratogenic risk is him also theoretical. It is however advisable by prudence to discuss with the patient his desire pregnancy and to inform it of the state of current knowledge. This information should be made not only when it is set up a couple metal/metal but also when it is set up a prosthesis of which one of the parts of friction is metal.

* Learning curve: the realization of a patching of the hip is a novel method. The presence of the head of the neck obstructs to carry out the joint replacement   under good conditions; the good positioning of the cup asks for the training of gesture and new concepts.  It is often difficult for a surgeon who controls his technique of total prostheses well standards to admit to make run to his patients additional risks the time of learning curve. This is why we plead for the technique guided by pin which simplifies learning curve largely. ⁽⁹⁾

* The good choice of the implant depends primarily on the stem which could be installation during the recovery. Indeed it is absolutely prohibited to change manufacturer during the recovery joint replacement. the type of being different according to society just as congruence enters the parts.

* The absence of retreat: The retreat becomes consequent with well followed series (2, 23,24). The reliability curve of this type of implant oscillates between 99% and 94% to six years according to the authors.

Conclusion

The total patching of the hip is an old principle that progress of engineering and tribology inserts in the therapeutic arsenal of the advanced articular lesions. The patching of the shoulder gives satisfactory results in parallel. To carry out a patching requires a rigorous selection of the patients by avoiding the elderly, the obese ones and the subjects whose bones have an overall or local mechanical resistance insufficient. It is advisable to choose a technique of sighting for the positioning of the cup simple and reliable. Learning curve must start with exchange rates centered on the procedure as that which we proposed on December 14th, 2007 in Toulouse, follow-up of inspection in surgeons who practice this technique regularly. Then it is necessary to be put at the realization of total arthroplasties of hip for pivot at famous person by the channel of access chosen for the patching in order to familiarize itself with the positioning of the piece and finally one can put oneself at the realization of a patching at a thin and dynamic man with a good osseous capital. 

Bibliography 1. H, P, F, coll E. Metal-one-metal surface : study. J Gasket Surg 86-A: 28-39, 2004. 2. HC. Present off metal-one-metal . J Surg csotcina.com 17:12 - 16, 2008. 3. HC. Technical . csotcina.com Covering joint Am 13: 018 432, 1982. 4.     HC, TELEVISION NEWS, . off metal-one-metal type-I II . J Gasket Surg Am 89: 378 906, 2007. 5. HC, Campbell AP, . Fracture tea off off tea femur surface off tea . J Gasket Surg Am 86-A: 8374 1277, 2004. 6. EP, HC. Guideline off femoral tea off in surface tea . J Gasket Surg Am 87:1162, 2005. 7. EP, Campbell AP, R, F. off femoral tea off tea : study has. J Gasket Surg Br 88:35 - 39, 2006. 8. P. Use off has guide in . Osteology 14:65 - 68, 2005. 9. P, . Total prostheses of Hip: choices. Paris: 2005, p 951 162 10. , MT. Total Metal-one-metal : tea ? J 20: 374 129, 2005. 11. MY. Total surfaces . Covering joint csotcina.com LMBO 2-4, 1978. 12. , McGee MY, K, Serious SE. total Metal-one-metal replacement-tea been worth off has . csotcina.com Covering joint Am 36: 199 441, , 2005. 13. M, J, M, , R, Mr. : leaves I. Technical off joined . Covering joint csotcina.com LMBO 61-66, 2004. 14. , HC, . obese Metal-one-metal patients. J Gasket Surg Am 89: 2307 3711, 2007. 15. M, R. off femoral tea Birmingham . With technetium Tc good /individual photon issuing study. J 22: 774 768; 985 756, 2007. 16. DR., TM, RH, RE, Ulrich , Mount MY. Femoral fractures total metal-one-metal : prospective study has. J 22:66 - 71, 2007. 17. CW, , Thomas AM, RB, PB. influences off one in Birmingham . Covering joint csotcina.com LMBO 466: 938 326, 2008. 18. D, R, Flax K, P. Metal one metal surfaces off tea . Experiment off tea . Covering joint csotcina.com LMBO , 1996. 19. , . Surface : off tea seventy-furnace consecutive boxes At tea off , San Francisco 156 966, 1982. 20. , NA, U, O. Sports . Am J Sports 35: 786 709, 2007. 21. TC, RP, , . off tea Young activates patient off tea . With off total metal-one-metal . J Gasket Surg Br 88: 991 201, 2006. 22. C, Michael , P, . navigation off tea implant . csotcina.com 2007. 23. , HP, Hoist J, , R, P, , OUT OF ORDER . off tea Birmingham : YEAR SERIES. J Gasket Surg Br 90: 936 446, 2008. 24. RB, CW, PB. Birmingham . With minimum off . J Gasket Surg Br 87: 366 277, 2005. 25. AP, M, Mr. urine metal ion levels in Young activates patient Birmingham . J Gasket Surg Br 89:989; 939 940, 2007. 26.     AP, S, AG, Dupont C, Mr. cobalt ion tea content , metal-one-metal surfaces off tea . J Gasket Surg Br 89: 340 743, 2007. 27. Wagner H. Surface off tea . Covering joint csotcina.com LMBO 432 730, 1978.