Posterior approach for total hip arthroplasty

Experience with the posterolateral approach to total hip replacement arthroplasty in 229 patients is reported. The technic has the advantages of providing excellent exposure and decreased operative time, minimal blood loss, and absence of the complications associated with removal and replacement of the greater trochanter. Capsulectomy may be done or not, as desired. Classification of results was based on absence of pain and increased range of motion. Of the 229 patients, 95% were classified as having a good to excellent result; 2%, a fair result; and 3%, a poor result. There was no statistically significant correlation between the postoperative formation of ectopic bone and whether or not capsulectomy was done.

Advances in surgical technique for total hip replacement: without and with osteotomy of the greater trochanter

Advances in the surgical technique for total hip replacement demonstrate that in most straightforward cases, osteotomy of the greater trochanter is unnecessary. This point of view requires some consideration of the present controversy about the need for osteotomy of the greater trochanter. If the limb is to be shortened or if a graft is to be added to the ilium, the trochanter must be removed. In complex cases necessitating revision operations or correction of severe deformities, or in hips requiring long stem components, osteotomy of the trochanter can be a distinct asset. There are pitfalls and complications of the techniques, both with and without trochanteric osteotomy, as well as with methods of reattachment of the trochanter. In general, total hip replacement can be performed with wide exposure of the socket without osteotomy of the trochanter, and can be performed without damage to the abductor muscle group. New cementing procedures and more accurate positioning of the femoral component have significantly improved the end results of total hip arthroplasty.

Resurfacing arthroplasty of the hip. Biomechanical, morphological, and clinical aspects based on the results of a preliminary clinical study

As an alternative in total hip replacement the so called resurfacing arthroplasty of the hip is gaining wider acceptance. The procedure can be said to be a modernisation of the original Smith-Pedersen operation and is suggested in young people with degenerative hip disease, congenital hip dysplasia or Perthes' disease. The advantages are that the femoral head and neck are retained and thus no femoral stem prosthesis is necessary. The greatest disadvantage is that in case of socket loosening a secondary operation might not remain as successful as could the initial operation with a socket which is not as large as those recommended for the resurfacing procedure. In this presentation a preliminary report of a one-year material is presented together with a presentation of advantages, disadvantages, and the biomechanical appraisal of resurfacing of the hip. Fifteen patients with 17 hips have been operated and followed-up and by using the Merle d'Aubigné evaluation there was an improvement of some 3--4 points in pain, walking, and total motion. Patient opinion indicated 80% satisfaction. The management of two serious complications is also described.

Intramedullary pressure patterns

The insertion of cement and femoral prosthesis in total hip replacement produces biochemical abnormalities. These are thought to be caused by a marked rise in intramedullary pressure. Surgeons aim to reduce these pressures by using different methods of insertion and venting. The present investigation was undertaken to establish if any one method was superior to the others. The greatest modification of acrylic pressure was obtained by means of a drill hole. Thie highest rise in pressure was produced by the insertion of the femoral prosthesis and this was little modified by any of the alternatives of the use of a 3/16 inch drill hole, a 16-gauge catheter, and cement gun.

[Experiences with the surface replacement arthroplasty of the hip joint (author's transl)]

In comparison with the total hip joint replacement the surface replacement arthroplasty of the hip according to Mr. H. Wagner seems to have some advantages. Personal experiences based on 152 operations and follow-up examinations at least half a year after the incision confirm this impression.

Histomorphological investigations of coxa femoral ends following double-cup arthroplasty according to Freeman

Of 20 shell prostheses inserted in cases of early coxarthrosis in our clinic during the period from mid-1976 to the end of 1978, three had to be removed. Morphological examinations, employing different techniques, were made of the coxa femoral ends which were removed. The foreign body reaction of the bone tissue beneath the cement within the prosthetic shell and the biomechanical response were investigated on the basis of macroscopic and microscopic structural analyses. Dependent upon the time elapsed, the exposed spongiosa surface was observed to have become remodeled to a thin cortical protective layer. Independent of time between insertion and removal of the prosthetic shell, a continuous wide layer, consisting of cellular and fibrous tissue, was formed between the bone and the cement (which remained intact) even after the formation of the above-mentioned cortical bone substrate.

Controlled hypotension in hip joint surgery. An assessment of surgical haemorrhage during sodium nitroprusside infusion

Controlled hypotension, combined with light balanced anaesthesia, was employed during total hip replacement operations on 25 patients. Sodium nitroprusside (Nipride, Roche), in the form of a 0.01 per cent (100 micrograms/ml) infusion, was used as a hypotensive agent. The mean arterial blood pressure (MABP) was lowered from 108 to 64 mmHg (range 60--70) (P less than 0.001). The average blood loss during the operations was 212 ml and none of the patients required homologous blood transfusion. In comparison with 25 normotensive patients undergoing similar surgery, the difference in the mean volume of haemorrhage between the two groups was 826 ml (P less than 0.001). The difference in the total haemorrhage, however, between the same two groups was 518 ml (mean) (P less than 0.01). The results were compared with those of another investigation in which epidural anaesthesia was used to diminish bleeding during surgery on the hip.

Femoral shaft perforation: a complication of total hip reconstruction

Perforation of the femoral shaft by the stem of the prosthesis is a rare, but serious complication following total hip replacement. It is a complication that is avoidable if meticulous attention is given to preoperative planning and intraoperative technique. The major predisposing factors for this complication are previous hip surgery, hip dysplasia, osteoporosis and poor exposure. Every attempt should be made to discover a perforation during surgery and to correct the alignment of the femoral stem. The patients who have experienced this complication have had a poor result suffering pain, loosening or femoral shaft fracture necessitating surgical revision.

A method of management of the fractured stem in total hip replacement

A method of removal of the fractured stem of a total hip replacement consists of drilling the distal fragment and extracting it through the open neck of the femur. Good exposure and careful preparation of the medullary canal to take a heavier stem in a well supported position will prevent stem fracture. Extended neck prosthesis may be indicated to ensure stability. Secure reattachment of the trochanter is essential.

Experimental reaming of the proximal femur and acrylic cement implantation: vascular and histologic effects

The technique of microangiography and correlated histology was used, in experiments on the proximal femora of mature mongrel dogs, to study the effects of simple medullary reaming and of reaming followed by insertion of acrylic cement. The hip joints were not disturbed. A segment of Steinmann pin, representing the stem of a hip prosthesis, was inserted into the cement as it was polymerizing. The most significant results, after reaming alone, were devascularization and apparent necrosis of large areas of the cortex of the subtrochanteric femoral diaphysis. Full recovery was observed in 6 months. However, when acrylic cement was introduced following the reaming, extensive necrosis of the inner layers of the diaphyseal cortex was still present after a year, when the observations were terminated. The presence of necrosis of bone was judged by the lack of visible osteocytes in the lacunae. After the devascularization caused by filling the diaphyseal medulla with acrylic cement, the apparently necrotic cortex was revitalized without osteoclasia. That is in contrast to the results in another study in which osteoclasia and osteoneogenesis were required to restore cortex with empty cell lacunae. This raises the question of dormant osteonecrosis in contrast to total osteonecrosis. These studies show, in thin histologic preparations, acrylic bone cement in situ in the tissues. A fibrous membrane was found at the cement-bone interface in most areas. It was thicker in the diaphysis than in the metaphysis. The physiologic effects of acrylic cement implantation are considered to be likely factors in the loosening which is observed clinically when the femoral components of hip prostheses are under protracted stress.

Effect of gentamicin on shear and interface strengths of bone cement

Antibiotic impregnated cement offers a potential method for salvage of infected total joint replacements. The addition of gentamicin in concentrations of .5, 1.0, and 2.0 per 40 significantly affects the shear strength of Palacos acrylic bone cement. The clinical significance of this strnegth drop is not clear. Large grained antibiotic additives have deleterious effect on shear strength. Measurements were made to determine the effect of gentamicin concentration on the bone-cement interface strength but no trend could be determined. The interface strength was much less than the strength of Palacos alone and suggested that bone strength is the limiting factor.

Mechanical stability of the greater trochanter following osteotomy and reattachment by wiring

Greater trochanters of fresh and formalin-perserved cadaver femora were osteotomized, rewired using techniques described by Amstutz, Charnley, Coventry and Harris, and then mechanically tested. Force simulating abductor muscle pull was applied to the trochanter in the plane of section while its displacement was measured continuously with an extensometer. Although many trochanters appeared rigidly fixed when stressed manually, all displaced visibly when 27 kg load was first applied. When released, permanent sets averaging 0.1 mm (Charnley and Harris) to 3--4 mm (Coventry) were measured. Subsequent repeated loadings (0--27 kg) from this new "rest" position produced recoverable cyclic "functional" displacements averaging 0.7 mm (Charnley and Harris) to 2.3 mm (Coventry). With the exception of the specimens wired by the Coventry technique, results for a simulated 45 degrees anterior pull were generally comparable to those for a neutral pull. Ultimate failure loads of the trochanteric fixation were on the order of 110 kg for selected fresh specimens.

Trochanteric osteotomy: analysis of pattern of wire fixation failure and complications

Problems and complications following trochanteric osteotomy in 277 total hip replacements demonstrated that while the value of trochanteric osteotomy is obvious, the incidence of problems and complications in 277 total hip replacements was about 15%. Analysis was made of the location and sequence of wire failure following different techniques of trochanteric wiring. The usual method of wire failure was by fatigue fracture, although early fracture in the post-operative phase may be secondary to tensile failure, The incidence of wire tensile failure can be increased by inadvertent kinking or scoring of the wire during trochanteric fixation. An ununited trochanter should be protected against wire failure and its sequelae.

An uncemented total hip replacement: experimental study and review of 300 madreporique arthroplasties

Mafreporique arthroplasty is not intended as a bustitute for acrylic cement stabilized arthroplasty but is available as an effective alternative. An experimental and clinical investigation including radiological analysis of 300 madreporique arthroplasties has convinced us of the reality and reliability of biological anchoring by endosteal osteogenesis. The madreporique method does not result in any local or general complications usually associated with the cement technique. Full weight-bearing is permitted at the same postoperative time as the cemented prosthesis. The results at early and interim follow-up periods compare favorably with cemented hip arthroplasties. Living bone that undergoes remodelling provides for long-term anchor of the prosthesis and eliminates the chemical intermediary which leads, more or less, with time to loosening of the implant in a significant number of cases.

The Giliberty bipolar prosthesis: a clinical and radiographical review

An interim report of 65 Giliberty bipolar hip units followed for an average of 19 months shows excellent short-term results in regard to their clinical condition. Radiographic study of the prosthesis with special attention to cup movement portends a favorable long-term result. Nevertheless, the snap-fit mechanism of the prosthetic head in the cup and the moving cup justify a cautious attitude until a larger series of a longer term can be completed.

Replacement arthroplasty using the Charnley prosthesis in old tuberculosis of the hip

This report is based upon a retrospective study of a consecutive series of twenty patients who had tuberculosis of the hip in quiescent state. Two patients had only a short history but were included in this study. An interesting feature at the time of operation was that in many cases the bone showed old features of tuberculous disease despite the long history of quiescence. A modification of the Charnley technique is discussed. In addition, details of radiographic assessment before operation, antituberculous drug therapy and the use of Kanamycin in bone cement are given. The complications and results are recorded.

Long stem femoral components for total hip replacement

Certain special problems in reconstruction of the arthritis hip in the adult require the use of a femoral component that has a long stem. A long stem component is essential if a major defect exists in the cortex of the proximal portion of the femur. Examples of such defects are windows cut in the femur to remove cement or to remove a broken femoral stem. Another example is the hole made by penetration of a femoral stem through the cortex. Standard long stem components are used for these cases. A new device in the long stem family, called the calcar replacement long stem component, is designed to restore leg length in those cases in which the femoral calcar has been removed or resorbed. It is also being used in certain cases of heterotopic ossification. In certain cases of primary or secondary malignant disease the entire proximal portion of the femur is excised and the proximal femoral replacement long stem component is inserted. The use of these long stem femoral components is illustrated and the limitations and pitfalls are discussed.