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E W Morscher

Publications and source records attributed to E W Morscher.

At least 19 recordsLinked to original sources
PubMed2005

Ten-year survival of the MS-30 matt-surfaced cemented stem.

The Morscher-Spotorno (MS-30) femoral stem is a stainless-steel, straight, three-dimensionally tapered, collarless implant for cemented fixation in total hip replacement. We report the results at ten years of a consecutive series of 124 total hip replacements in 121 patients with the matt-surfaced MS-30 stem and an alumina ceramic head of 28-mm diameter. All the stems were fixed with Palacos bone cement with gentamicin using a modern cementing technique. They were combined with an uncemented, press-fit cup. The mean period of observation was 10.2 years (8.3 to 12.1) and no patient was lost to follow-up. Twenty-seven patients (22%) died with the implant in situ. Nine could only be interviewed by telephone. We included 85 patients with 88 hips in the clinical and radiological follow-up examinations. None of the stems or cups had been revised. The Harris hip score was excellent or good in 97% (85 hips) and moderate in 3% (three hips). Radiologically, six hips (6.8%) had osteolysis adjacent to the stem, mostly in Gruen zone 7. Twenty (22.7%) showed one or more radiolucent lines. Twenty-two stems (25%) had subsided by 2 mm to 5 mm. In these cases two showed osteolysis (9.1%) with subsidence and four without (6.1%). Radiolucent lines were seen in seven with migration (31.8%) and in 13 without (19.7%). No infections and no acetabular osteolysis were observed. The clinical results were excellent with survivorship after ten years of 100% and only a slightly statistically non-significant higher rate of osteolysis and radiolucency in cases of subsidence.

Acetabulum↗
PubMed2005

Outcomes of the MS-30 cemented femoral stem.

The MS-30 (Morscher-Spotorno) cemented femoral stem is a straight, three-dimensionally tapered, collarless implant for cemented fixation in total hip replacement, manufactured from a FeCrNiMnMoNb-alloy. This paper documents the review of 4 original follow-ups performed at four orthopaedic hospitals: three at the author's institution (Basel/Switzerland 2, Pietra Ligure/Italy 1), and one at the University Orthopaedic Hospital of Heidelberg/ Germany. A total of 911 hips in 867 patients have been provided with the MS-30 stem. All stems were fixed with Palacos bone cement, the great majority with antibiotic (Gentamicine) loaded cement. The mean observation time was 10.2, 5.6, 10.2 and 6.5 years. One hundred and sixty-four hips were lost due to patients death, 121 patients were unable to come to the follow-up check. Ten patients only were lost to follow-up. The total number of hips with a clinical radiological follow-up was 597. The clinical and radiological assessment was in accordance with the International Documentation and Evaluation System (IDES) forms from the Institute of Documentation of the M.E. Müller Foundation in Berne/Switzerland. RESULTS The overall survivorship in the four follow-ups were 100% after 10 years, 98.4% and 99.2% after 5.5.years, 98.5% after 10 years and finally 96.1% after 6.5 years. The respective percentages of survival for aseptic loosening were 100%, 99.2%, 100%, 98.5% and 98.8%. CONCLUSION According to the NIH (National Institute of Health, United Kingdom) a survival rate of 95% regarding aseptic loosening justifies or even recommends further clinical use of the respective endoprosthesis system.

Aged↗
PubMed2003

Failures and successes in total hip replacement--why good ideas may not work.

The course of development of total hip replacement (THR) is neither harmonious nor linear. Progress and set-backs alternate. Progress in THR manifests itself through reductions in the number and the severity of complications (infection, aseptic loosening, prematurely worn components, etc.). Innovation is the motor of progress. However, today's innovation may well be tomorrow's revision! Progress has been achieved in part through new implant materials and designs that provide improvements in such things as stress distribution in surrounding bone, tissue compatibility and osseointegration, and resistance to both wear and cyclic fatigue. Of at least equal importance, however, are improvements achieved in operative procedures (e.g., cementing technique) and finally, in clinical quality control: more complete documentation of implant and patient variables, establishment of implant registers, and utilization of outcome studies to guide the course of further development. Causes of failure in THR are numerous. However, unexpected side effects of innovations are the most frequent cause. An innovation may solve one problem, but also creates new ones. Problems in innovation which can lead to failures include: over-generalization of expected patient responses, ignoring past experience or assigning wrong causes to encountered problems, and finally, ignoring the dynamic nature of the living system (which can be described as using "necro-" instead of biomechanical thinking). Quality control in both manufacturing and clinical practice has to be improved. The pioneer times have come to an end. Today's patients should have the right to be operated on by a well trained surgeon and to be provided with well tested, well-understood implant materials and devices. Progress in endoprosthetics has led to the present high level of clinical success. Paradoxically, however, success is the greatest obstacle to further progress. This is because the curve of progress as a result of effort expended has turned asymptotic in endoprosthetics, as it does in many endeavors. In such situations the more a product (e.g., surgical implant and procedure, automobile design, computer program) becomes successful, the more efforts (and finances) are needed for further progress. On the other hand, the "scissors"--created by crossing what might be feasible with what resources are available--open widely and can cut sharply. In fact, financial restrictions may force orthopaedic surgeons and the medical device and technology industry to turn to lower technologies in the future. However, whatever new developments in endoprosthetics may bring (be they sophistications or simplifications), we must remain open-minded and not assume things to be facts until there is evidence to support them.

Arthroplasty, Replacement, Hip↗
PubMed2003

Acetabular revision in total hip replacement with a press-fit cup.

The need for supplementary screw fixation in acetabular revisions is still widely debated. We carried out 439 acetabular revisions over an eight-year period. In 171 hips with contained or small segmental defects, the Morscher press-fit cup was used. These revisions were followed prospectively. No screws were used for additional fixation. A total of 123 hips with a mean follow-up of 7.4 years (5 to 10.5) were available for clinical and radiological review. There was no further revision of a press-fit cup for aseptic loosening. Radiological assessment revealed osteolysis in three hips. Of the original 171 hips there was cranial and medial migration of up to 6 mm at two years in 44 (26%). No further migration was seen after the second post-operative year. Acetabular revision without screws is possible with excellent medium-term results in well selected patients.

Acetabulum↗
PubMed2002

Load transfer and fixation mode of press-fit acetabular sockets.

Adequate initial fixation is a prerequisite for osseointegration and secondary stability of noncemented cups. Physiologic force transmission between the cup and acetabulum guarantees the best long-term fixation. To study load transfer within the natural hip joint and in the bone-implant interface of 2 different hemispherical noncemented press-fit cups, 10 hips were investigated in an experimental setup simulating single-leg stance. Load distribution and contact area were measured using prescale pressure-sensitive films and digital image analysis. Three dominant locations near the periphery of the acetabulum could be identified. Main load transfer occurs in the cranial region of the acetabulum, where it is buttressed by the iliac bone; the second location is at the posterior-inferior region at the ischial facet, and the third location is at the anterior region, where support is provided by the pubic bone. Peripheral rim contact was present in both cups but not completely circumferential. It showed marked loading at the same 3 locations similar to the natural hip joint. The ilioischial diagonal axis produced the highest press-fit. Peak local forces were found at the ischial and iliac facets. Local forces can be grouped into an iliac, an ischial, and a pubic group contributing 55%, 25%, and 20% to the total hip joint force. Pole contact was not present in the natural hip and with the biradial press-fit cup with flattened pole area but was observed with the pure hemispherical cup. Hence, stable fixation of an acetabular cup is achieved best by a 3-point-like bony support at the iliac, ischial, and pubic bone. The acetabular fovea does not provide functional support of the femoral head or endoprosthetic socket. In revision surgery, remaining peripheral bone stock at the iliac, ischial, and pubic locations allows stable implantation of primary cups.

Acetabulum↗
PubMed2002

Current state of cement fixation in THR.

The author surveys important landmarks in the development of total hip arthroplasty, with an accent on implant fixation using acrylic cement. He explains why he personally opted for hybrid prostheses, combining a cemented stem and a cementless socket, in patients over sixty years. Excellent cementless, sockets have been available for a long time; on the femoral side, the first steps were difficult, but several cementless, stems were subsequently developed, which provided excellent long term results. This historical evolution resulted in a very uneven use of cemented versus cementless stems from one country to another in Europe. Cemented implants have enjoyed a renewed popularity over the past few years as a result of several factors, including economical factors. The author discusses the conditions for optimal fixation of a cemented stem; these conditions are not always met satisfactorily, as a number of surgeons obviously stick to a crude cementing technique. The author describes the role of the stem geometry and surface finish, as well as the possible influence of a centralizer; he explains why, based on a correct analysis of the available data, discredit has been unduly cast on cemented stems made of titanium alloy. He insists on one important although often disregarded factor: the specific type of cement used, as better results have clearly been achieved with certain cements than with others. He insists on the necessity to take into account all the elements involved, in order to avoid making erroneous conclusions. He also insists on one very important variable, the quality of the surgical technique. Total hip arthroplasty is likely to make further progress in the future, although we are likely now in the asymptotic portion of an ascending curve. Further improvement in clinical results will result from improvement of currently existing systems and optimization of surgical technique, rather than from the continuous designing of new implants.

Alloys↗
PubMed2002

[Cementless socket fixation based on the "press-fit" concept in total hip joint arthroplasty].

PURPOSE OF THE STUDY: The key problem of implant fixation in THR is stress distribution, i.e. load transmission between bone and implant. The closer the load transfer is to the original physiological situation, the easier the adaptation of the periprosthetic bone to the new biomechanical conditions after implantation of the cup and the safer is its longlasting fixation. The aims of the studies were 1) to get information about the physiological load transfer in the normal hip joint, 2) to get information about the load transfer between acetabulum and acetabular sockets and vice versa, 3) to measure the periacetabular pelvic bone deformation as the stimulator of the remodelling process (third stage of osseointegration) in the normal hip joint and in hip joints fitted with different acetabular cups, 4) to study the morphological stages of osseointegration of a non-cemented press-fit cup and to compare the morphological structure of the periacetabular bone with the biomechanical data obtained by the in vitro studies and finally, 5) to compare the clinical and radiological outcome of follow-up studies of the senior author's "Press-Fit cup" with the theoretical hypotheses according to the experimental observations. MATERIAL AND METHODS: Load transfer between the acetabular bone and the femoral head on one side and press-fit cups has been determined by strain gauge measurements, finite element studies, pressure sensitive Fuji prescale films, CT-osteoabsorptiometry and telemetric measurements. Periacetabular deformation has been measured by Imetric Markers. Osseointegration of the senior author's press-fit cup and, thus, the remodelling process of the bony structures adjacent to the cup have been studied in autopsy specimens of THRs which have been in situ for several years. RESULTS: Load transfer measurements have shown that the main load in the original acetabulum as well as in the acetabulum fitted with a press-fit cup is transmitted to the periphery, especially to the acetabular cortical rim whereas the subchondral bone is exposed to lower, predominantly meridional (tension) stresses. Direct measurements of the periacetabular deformation under load revealed an increase of the peripheral press-fit with increasing stability of a (oversized) press-fit cup. Both the normal as well as the acetabulum fitted with a non-cemented cup deforms in a postero-medial direction. The histo-morphology of the periacetabular bone of autopsy specimens showed excellent bony in- and ongrowth of a porous titanium coating (SULMESH) and bone formation, especially at the periphery in zone 1 and 3 according to DeLee and Charnley. CONCLUSION: The studies have shown that the subchondral bone plate of the acetabulum has very little supportive function for non-cemented press-fit cups. For the preparation of the acetabulum it is, therefore, more important to ream the sclerotic subchondral bone until there is a well vascularized, well bleeding bone bed to facilitate osseointegration of a non-cemented acetabular socket than to preserve the subchondral bone plate as is the case in cement fixation. A non-cemented press-fit socket must transmit load predominantly to the cortical bone of the acetabular rim. Therefore, a too far medial positioning of the cup, and therefore loosing contact to the cortical rim, must be avoided under all circumstances. The clinical experience with acetabular revisions and with conversions of hip arthrodeses into a THR (where there is no subchondral bone at all) have shown the superiority of a well vascularized over a sclerotic (even mechanically stronger) bone bed. Furthermore, it has been shown that the additional use of screws for fixation of an acetabular cup is not only unnecessary but can be deleterious and causes complications including osteolysis and aseptic loosening.

Acetabulum↗
PubMed2001

Fifteen-year results of the Müller CoCrNiMo straight stem.

Between September 1980 and May 1982, 112 primary unilateral total hip arthroplasties with the original cemented M. E. Müller Straight stem (manufactured from Protasul-10, a CoCrNiMo alloy) were inserted in 109 consecutive patients, all combined with non-cemented, non-coated polyethylene RM cups. Forty-three patients (40%) died during the follow-up period, all with the implant in place. Of the 66 surviving patients, 2 (1.8%) were lost to follow-up, and 7 (6.3%) were unable to attend the 15-year clinical and radiological follow-up. Eight stems (7.3%) had to be revised for aseptic loosening and 3 stems (2.7%), for septic loosening. The 15-year survivorship of the Müller Straight stem regarding aseptic loosening is, therefore, 92.7%. Forty-six patients with 49 total hip replacements could be evaluated clinically and radiologically after 15 years. The mean duration of clinical follow-up for these 46 patients (42.2%) was 14.8 years (range 12.8-16.5 years). There were 22 women (48%) and 24 men (52%). The mean age at the time of the operation was 62 years (range 38-80 years), and 78 years (range 59-93 years) at the time of the latest follow-up. The mean Harris Hip Score at the latest follow-up evaluation of the 49 hip joints was 85 points (range 34-100 points). Of the 46 patients, 39 (85%) had a good or excellent clinical result. Radiographic follow-up was performed for 49 hips: 35 (70%) had linear or focal osteolysis in one or more zones of the stem, but only 4 (8%) had evidence of definitive loosening (linear radiolucency of over 2 mm all around the stem). Subsidence of over 2 mm was found in 20 hips (41%), 6 of them within the cement mantle. There was no correlation between subsidence and pain. The cause for the poor results is primarily the high rate of aseptic loosening of the non-coated, non-cemented all-polyethylene RM cups, with a loosening rate of 63% and a revision rate of 25% after 15 years.

Adult↗
PubMed2001

Nine-year results of Müller cemented titanium Straight Stems in total hip replacement.

At the Orthopaedic Department of the University of Basel, a total of 540 cemented Müller titanium alloy (Ti6Al7Nb) Straight Stems were inserted between 1989 and 1993. A cohort of 120 consecutive patients (66 women, 54 men) with 126 prostheses operated on between March and December 1989 were followed clinically and radiologically in a prospective manner for a mean observation time of 9.1 years. In all cases, the Müller titanium alloy Straight Stem was combined with the senior author's (E.W.M.) Press-Fit Cup. The mean age of the patients at surgery was 66 (range 43-93) years. Fourty patients (41 hips) died, 9 were interviewed by telephone, none was 'lost to follow-up'. Seventy-one patients with 76 hip replacements were available for the follow-up. Four hips had been revised: two of them due to aseptic loosening of the femoral component, one because of a late infection--all after 9 years--and one owing to a periprosthetic fracture after 6 years. The 9-year overall survivorship is 96.8%, and for aseptic loosening of the stem 98.4%. None of the cups had to be revised for aseptic loosening. The clinical result (according to Merle d'Aubigné) was excellent and good in 88%, moderate in 8%, and poor in 4%. The radiological analysis showed no osteolysis or radiolucent lines in 59 prostheses (78%). Nine stems (12%) showed a radiolucent line. Focal osteolysis was detected in 8 cases (10%) in one or more Gruen zones. The distribution of the osteolyses shows that predominantly zones VII, VI, V, and II are affected in decreasing frequency. No osteolysis was detected on the acetabular side. Our results do not confirm the high rate of osteolysis and revisions with the Müller titanium alloy Straight Stem presented by some other institutions. The verdict on a specific endoprosthetic implant must be made by combined assessment of the design, the implant surface condition, the material, the cement, the cementing procedure and the operative technique. The statement made in earlier publications that cemented titanium alloy should not be used as a femoral stem prosthesis should be reconsidered.

Adult↗
PubMed1999

Femoral neck lengthening osteotomy after growth disturbance of the proximal femur.

Treatment of congenital dislocation of the hip, Perthes disease, bacterial coxitis, or fractures in childhood may be complicated by vascular insufficiency and subsequent growth disturbance of the proximal femur. The resulting deformity, with a high-standing greater trochanter and a short femoral neck, causes leg length shortening and insufficiency of the hip abductors with a positive Trendelenburg sign and limp. Normal anatomy and biomechanics of the hip joint can be restored by lengthening the femoral neck after two parallel osteotomies of the femur at the the upper and lower border of the femoral neck, followed by distalization the greater trochanter. This femoral neck lengthening osteotomy was first described by the senior author (EM) in 1980. This retrospective study of 37 operated patients with a mean follow-up of 8 years shows good results in 32 patients with little or no preexisting osteoarthritis. Four of five patients with marked degenerative changes underwent a total hip replacement within 1 to 9 years after the osteotomy.

Adolescent↗
PubMed1998

Severe osteolysis after third-body wear due to hydroxyapatite particles from acetabular cup coating.

One concern about the fixation of HA-coated implants is the possible disintegration of the surface, with the migration of HA granules into the joint space, producing third-body wear. We report a study of six revisions of HA-coated polyethylene RM cups at 9 to 14 years after successful primary arthroplasty. In all six hips, we found HA granules embedded in the articulating surface of the polyethylene, with abrasive wear of the cup and the metal femoral head. The cup had loosened in four hips and three showed severe osteolysis of the proximal femur. Third-body wear due to HA particles from implant coating may produce severe clinical problems with few early warning signs. Further clinical, radiological and histological observations are needed to determine the possible incidence of this late complication in the various types of coating of a variety of substrates.

Acetabulum↗
PubMed1997

[Not Available].

Explore the source record for details and available documents.

Journal Article↗
PubMed1997

[Contact surface and pressure load at implant-bone interface in press-fit cups compared to natural hip joints].

The implantation of an endoprosthetic socket into the acetabulum alters the mechanical stresses in the periacetabular region in a significant manner compared with the natural hip joint. In this way, a remodelling process is initiated. Primary stability to achieve osseointegration and a loading of the acetabulum owing to the biomechanical interaction between cup and bone that is similar to the natural joint, are important prerequisites for a long-term bony integration of the implant. Therefore, the intra-articular pressure distribution in eight hip joints of fresh-frozen human pelvic cadavers and in the bone/implant interface of two press-fit cups was investigated using pressure-sensitive Prescale films. A modular cup with a pure hemispherical shape (PCA cup) and a monoblock cup with a biradial surface and flattening of the pole (press-fit cup) were tested. Loads of up to twice body weight were introduced into the sacrum, simulating a single-leg stance with the hip in neutral flexion. The results were extracted from the pressure prints applying digital image processing methods. It was demonstrated that intra-articular contact occurs over the whole articular surface of the joint, with contact areas between 39.0% and 56.9% of the hemisphere, showing zones of higher pressures where the acetabulum is supported by the iliac, ischial and pubic bone. The biradial press-fit cup showed mean contact areas of 44.7% of its surface when inserted under press-fit only. This area was enlarged to 53.0% and to 64.2% with increasing load. The corresponding figures for the PCA cup are 45.1%, 48.9% and 57.1%. The low-profile PCA cup produces a small band of high pressure near the periphery, and with increasing load its pole area comes into contact with the acetabular fossa. Occasionally, irregular gaps do occur. The press-fit cup enlarges the contact area from the periphery to the pole within its optimised biradial contact zone until the lunar surface is loaded. The acetabular fossa remains unloaded owing to the flattening of the pole. This load distribution is close to that of the natural hip joint. The pressure distribution of both cups is also characterised by three zones at the iliac, ischial and pubic bones showing a higher load transmission.

Acetabulum↗
PubMed1995

Total hip replacement with solid autologous femoral head graft for hip dysplasia.

Acetabuloplasty with solid autologous femoral head graft for the treatment of hip dysplasia is an established method which creates the contained cavity needed to accommodate the artificial cup. In order to evaluate the medium- and long-term results of this method using a cementless hemispheric cup, 34 patients (39 hips) operated on between 1979 and 1986 were clinically and radiologically reviewed. The minimal follow-up was 5 years (average 7.6 years). The Harris hip score increased from 36 points preoperatively to 89 points 1 year postoperatively and to 85.1 at the last follow-up. On roentgenographic evaluation, all grafts had been incorporated and appeared to have tolerated the mechanical loading well. Partial resorption of the graft occurred in 22 of the 39 hips, mainly in the lateral non-loaded zone. Twenty-nine of the 39 acetabular components showed migration, on average 4.2 mm cranially and 1.8 mm medially; 92% occurred during the first 2 years, and thereafter it was not progressive. Smaller cups migrated consistently more than larger cups. A significant correlation was found between cup migration and the degree of bone coverage of the cup, and extensive migration occurred in most cases with cup coverage by the host bone of less than 40%-50% of the weight-bearing surface of the cup. Only one acetabular component was altered significantly, and another appears to have become loose. The use of the normal-sized cups and cementless fixation medially in the primary acetabulum are thought to have contributed to our favorable mid- to long-term results.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗