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C Eingartner

Publications and source records attributed to C Eingartner.

At least 19 recordsLinked to original sources
PubMed2006

Finite element analysis of a bone-implant system with the proximal femur nail.

Static analysis with finite element of a realistic femur nail bone-implant system in a typical proximal femoral fracture under physiological load bearing situations provides results for stress, displacement and strain. The question to be answered is, if simulation with the finite element analysis is able to explain biomechanically clinical observed patterns of failure. Surface-Reconstruction with CT database of a proximal femur and reconstruction with CT based density data was done. Next steps were to unite the bone structure with the Proximal Femoral Nail and to model two relevant fractures (31-A2.2 and A2.3 according AO). After modelling of geometry, isotropic material behaviour and load application numeric calculation of the femur-nail system with FE-software was performed. FE simulation mainly shows an axial dislocation of the femoral head screw with nearly no dislocation of the antirotation screw. This so-called z-effect therefore means: (1) Tilting of the proximal main fragment around the sagittal axis between the screws and (2) relative movement of both screws in the frontal plane. Relative movement of the two screws against each other could be the reason for implant failure, the so called cut out. Furthermore simulation shows different gliding of the screws explaining the so called z-telescoping. The analyzed stress patterns have to be relativized, because isotropic material behaviour of cancellous bone was assumed. Further examinations for this issue are necessary.

Biomechanical Phenomena↗
PubMed2005

Fractures of the distal tibia treated with closed reduction and minimally invasive plating.

INTRODUCTION: The treatment of fractures of the distal tibia can be problematical because of the thin soft-tissue covering. Bridging slide-insertion plate osteosynthesis is performed by indirect, axially correct reduction of the fracture and stabilization without opening the soft tissue at the fracture site. Stripping of the periosteum is thus avoided, the fragments remain integrated into the soft tissue, and healing occurs spontaneously by way of callus formation. MATERIALS AND METHODS: Seventy-one patients treated by slide-insertion plate osteosynthesis were followed up over at least 2 years. As would be expected in this anatomical region, the proportion of C fractures and fractures with concomitant soft-tissue damage was high. The majority of patients were treated by application of an external fixator on the day of the accident; the definitive osteosynthesis with the slide-insertion plate was performed at a later date after healing of the soft tissues. RESULTS: In 68 patients, fracture healing was achieved within 2 years. In 80% of the cases, the final X-ray follow-up showed no or tolerable axis deviations (<5 degrees) in the varus/valgus plane or in the recurvation/antecurvation plane. A deviation >10 degrees requiring a correcting osteotomy was found in only 1 patient. Postoperative complications were rare occurrences. Five patients required an additional cancellous bone graft to deal with inadequate bone healing. System-related complications (instability, malalignment) due to intraoperative technical errors only had to be corrected in revision operations in 2 patients. CONCLUSION: Closed reduction and minimally invasive plating offers the combined advantages of minimal soft-tissue damage with stable fracture fixation.

Adult↗
PubMed2005

Primary stability of various forms of osteosynthesis in the treatment of fractures of the proximal tibia.

The treatment of fractures of the proximal tibia is complex and makes great demands on the implants used. Our study aimed to identify what levels of primary stability could be achieved with various forms of osteosynthesis in the treatment of diaphyseal fractures of the proximal tibia. Pairs of human tibiae were investigated. An unstable fracture was simulated by creating a defect at the metaphyseal-diaphyseal junction. Six implants were tested in a uniaxial testing device (Instron) using the quasi-static and displacement-controlled modes and the force-displacement curve was recorded. The movements of each fragment and of the implant were recorded video-optically (MacReflex, Qualysis). Axial deviations were evaluated at 300 N. The results show that the nailing systems tolerated the highest forces. The lowest axial deviations in varus and valgus were also found for the nailing systems; the highest axial deviations were recorded for the buttress plate and the less invasive stabilising system (LISS). In terms of rotational displacement the LISS was better than the buttress plate. In summary, it was found that higher loads were better tolerated by centrally placed load carriers than by eccentrically placed ones. In the case of the latter, it appears advantageous to use additive procedures for medial buttressing in the early phase.

Biomechanical Phenomena↗
PubMed2003

[Cemented versus uncemented hip replacement--rational decision making using the BiCONTACT total hip system].

The BiCONTACT femoral stem has been developed as a modular system which is suitable for both cemented and uncemented implantation. A highly standardized procedure using an identical set of instruments for both modes of fixation ensures bone preservation. Primary stability is achieved by special design parameters. The cementless implants are coated proximally, thus facilitating osteointegration and proximal load transfer. Cemented stems provide an identical design but a smooth surface and are anchored by a homogenous cement mantle. The BiCONTACT stem is in use in the BG Trauma Center Tuebingen since 14 years and a consecutive series of 250 cases (series A) with uncemented implantation and of 250 cases (series B) with cemented implantation has been analyzed in two different prospective follow-up studies. Long-term survival after 11 years was 97.1 % (95 % confidence limits: 93.8 %-98.7 %) for series A, the follow-up rate was 99.2 %. For series B, the follow up-rate was also 99.2 %, survival estimate after 11 years was 97.5 % (95 % CI: 94.2 %-99.0 %).

Adult↗
PubMed2003

Long-term results with the BiCONTACT system--aspects to investigate and to learn from.

The BiCONTACT femoral stem for cementless fixation is being used without any technical modification after 15 years. The long-term results should be evaluated in this study. A consecutive series was continuously monitored in a prospective follow-up study. A survival analysis was performed, clinical results were rated according to the Harris score. There were 236 patients with 250 total hip replacements (THR); mean age at time of implantation was 58.2 years. Indications for THR included osteoarthritis (62.4%), dysplasia (16.8%), trauma (8.4%) and femoral-head necrosis (16.8%). Average time of follow-up evaluation was 8.9 years (range 7.4-10.7 years). At follow-up, 27 patients had died and two could not be located. Seven patients were revised--two for infection, one for recurrent dislocation, two for component undersizing with rapid subsidence, and one for aseptic loosening of a varus-malaligned stem; one radiologically well-fixed stem had been revised during acetabular revision. Survival estimate showed an overall survival rate of 97.1% after 11 years (confidence limits: 98.7% upper and 93.6% lower). Radiologically, tiny reactive lines (< 2 mm) were present in the distal zones of the femoral shaft, but no radiolucencies could be found in the proximal anchoring zone. Migration analysis with Ein-Bild-Röntgen-analyse/femoral component analysis (EBRA/FCA) demonstrated a very small amount of migration: in 31.0%, the overall migration was between 0.5 and 1 mm after 120 months; 8.5% had an absolute amount of subsidence exceeding 2 mm after 120 months (one case more than 3 mm). Mean subsidence was 0.2 mm after 3 months and 6 months, 0.3 mm after 12 months, and reached 0.5 mm after 10 years. An initial small amount of subsidence could be detected in 45.1%, and 15.5% had a late onset of subsidence. Continuous sinking could be found in 12.7%, while 26.8% had irregular patterns of migration. Clinical results were somewhat compromised by a higher-than-average rate of cup loosening (uncoated threaded cup). The average Harris hip score at follow-up was 84.3 points. Interestingly, no femoral osteolysis could be detected, even in cases with severe acetabular osteolyses, indicating sealing of the stem interface by tight osseointegration of the proximally-coated stem.

Arthroplasty, Replacement, Hip↗
PubMed2002

[Good long term results with a cemented straight femoral shaft prosthesis made of titanium].

A higher-than-average rate of aseptic loosening has been postulated to be associated with the combination of a titanium stem and bone cement. In this prospective follow-up study we therefore investigated our first consecutive series of 250 implantations of a cemented femoral shaft prosthesis made of titanium alloy (BiCONTACT((R)), Aesculap, Tuttlingen, Germany). Average time of follow-up evaluation was 9.7 years (range 8.7-10.3 years). At follow-up, mean patient age was 81 years; 89 patients with 93 hips have deceased and two could not be located. Follow-up rate was 98.7% for the patients still alive at time of follow-up evaluation. Five patients have been revised, two for infection and one for aseptic loosening of a varus-malaligned stem; two radiologically well-fixed stems had been revised during acetabular revision. Survival estimate showed a calculated cumulative survival rate of 97.5% after 11 years [confidence limits: 99.0% (upper) and 94.1% (lower)]. The average Harris hip score at time of follow-up was 82.25 points.Radiologically, signs of loosening could be detected in 3 stems: in one case varus malalignement deteriorated with time and in 2 cases osteolyses developed together with significant polyethylene wear. All 3 patients experienced only mild pain and revision had not been indicated so far. In conclusion, the long-term follow-up results with this cemented titanium femoral component are encouraging and are comparable to other successful cemented femoral components in primary total hip arthroplasty. No increased risk for aseptical loosening was associated to the combination of titanium and cement in this specific stem. Design parameters seem to play an important role in the development of aseptic loosening in cemented titanium stems.

Adult↗
PubMed2001

Results of a cemented titanium alloy straight femoral shaft prosthesis after 10 years of follow-up.

Two-hundred fifty implantations of a cemented femoral stem made of titanium alloy in 239 patients were followed for 9.7 years (range 8.7-10.3 years). Eighty-nine patients with 93 hips have died and two could not be located. Five hips have been revised, two for infection, one for aseptic loosening and two during revision of the cup. Three stems showed radiological loosening but have not been revised. The average hip score was 85. The results are encouraging and comparable to other cemented femoral stems.

Adult↗
PubMed2001

Allogeneic cancellous bone graft and a Burch-Schneider ring for acetabular reconstruction in revision hip arthroplasty.

BACKGROUND: There is an ever-increasing number of failed hip arthroplasties associated with massive deficiency of acetabular bone stock consisting of a segmental or cavitary defect. This study was undertaken to evaluate the long-term results after use of morselized cryopreserved allogeneic bone graft and an antiprotrusio cage to treat such a deficiency. METHODS: From January 1, 1988, to January 1, 1994, forty-one patients (forty-one hips) with an acetabular defect classified as type IIl or IV according to the American Academy of Orthopaedic Surgeons system were operated on with use of a Burch-Schneider ring and morselized cryopreserved allogeneic cancellous bone graft. Thirty-eight patients (thirty-eight hips) were available for clinical and radiographic follow-up examinations at an average of 7.3 years (range, 4.2 to 9.4 years) after surgery. RESULTS: All measured clinical parameters had improved significantly by the time of the follow-up examination (p < 0.0001). Radiographs confirmed that none of the thirty-eight hips had any measurable migration or displacement of the acetabular component and that osseous consolidation occurred only within the grafted area in all patients. CONCLUSION: Acetabular reconstruction with use of morselized cryopreserved allogeneic cancellous bone graft and the Burch-Schneider ring can be highly successful in managing massive acetabular deficiencies in revision hip arthroplasty.

Acetabulum↗
PubMed2000

Results of an uncemented straight femoral shaft prosthesis after 9 years of follow-up.

The first consecutive 250 implantations of an uncemented, proximally anchored straight femoral shaft prosthesis (BiCONTACT) in 236 patients are included in this prospective follow-up study. Average time of follow-up evaluation was 8.9 years (range, 7.4-10.7 years). At follow-up, 27 patients had died, and 2 could not be located. Seven patients underwent revision-2 for infection, 1 for recurrent dislocation, 2 for component undersizing with rapid subsidence, and 1 for aseptic loosening of a varus-malaligned stem; 1 radiologically well-fixed stem had been revised during acetabular revision. Overall survival was 97.1% after 11 years (confidence limits, 98.7% [upper] and 93.6% [lower]). The average Harris Hip score at time of follow-up was 84.3 points. Radiologically, tiny reactive lines (<2 mm) were present in the distal zones of the femoral shaft, but no radiolucencies could be found in the proximal anchoring zone. The midterm to long-term follow-up results with the evaluated femoral component are encouraging and are comparable to those of modern techniques of cementing in primary total hip arthroplasty.

Adult↗
PubMed1999

Growth factors in distraction osteogenesis. Immuno-histological pattern of TGF-beta1 and IGF-I in human callus induced by distraction osteogenesis.

Although growth factors have been demonstrated during bone healing, their presence has not yet been confirmed in callus distraction. Therefore, in 3 patients we searched for cytokines during callus distraction. Bone biopsies were immuno-histochemically stained for TGF-beta1, IGF-I, TGF-beta type II receptor, IGF receptor, and proliferating cell nuclear antigen (PCNA). Histologically we found immature woven bone in the middle of the callus zone and increasing calcification and lamellar bone in the re-modelling zone. Osteoblasts and fibroblast-like cells in the middle zone, and osteoblasts in all zones stained for TGF-beta and its receptor. The number of positive staining cells related to proliferous activity as assessed both by PCNA, and by bone density in radiographs. IGF-I could be detected everywhere. In conclusion, growth factors are present in bone formation and in areas of re-modelling during callotasis. Their relation to proliferous activity and radiographic density supports their involvement in osteogenesis.

Adult↗
PubMed1998

[Recurrent soft tissue infections after accidental inoculation with BCG vaccine].

Complications after BCG vaccine (bacilli Calmette-Guérin) occur rarely. They can reach from a local acute abscess to chronic ulceration's. Therapeutically concepts of these complications range from conservative to operative treatment. In the following case history recurrent soft tissue infections occurred after accidental inoculation with BCG vaccine. The time course of these recurrent infections with its therapeutic options is discussed and a treatment strategy is suggested. Currently, radical excision combined with antituberculotic treatment seems to be the most promising therapy of this specific soft tissue infection.

Antitubercular Agents↗
PubMed1998

Distalization of the patella during tibial callus distraction.

Consecutive distalization of the patella is described in two patients undergoing segmental transportation after high tibial corticotomy. Revision surgery with loosening and proximal reattachment of a portion of the patellar ligament bridging the callus distraction zone could re-establish the correct patellar position. Despite excellent callus formation after tibial corticotomy just below the tibial tuberositas, this procedure should be performed more distally as the fibers of the patellar tendon spread laterally and distally.

Adult↗
PubMed1998

[Injuries in sledding].

Tobogganing is a very popular outdoor winter recreational activity. In order to elucidate the patterns of injuries associated with tobogganing all patients with an injury caused by falls from or collisions while on or being hit by a sled were sampled prospectively between the period of November 1996 and March 1997. 50 patients were included in this study, aged from 7 to 69 years (mean 25.5 years). Of these, 14 (= 28%) patients required admission to hospital lasting from 1 to 31 days (mean 13.5 days), 11 (22%) needed an operation. Over all we could register 55 injuries; the lower extremity was the region most commonly injured (63.6%), followed by upper extremity with 21.8%. The most common injury was the sprain of the knee. The most severe injuries could be found at the lower limb and at the vertebral column, including four fractures of the lower leg and 8 ankle-joint fractures as well as two fractures of the lumbar spine. The most common single procedure was the open reduction and internal fixation of a fibular fracture. In 48.6% of the cases the riders struck an object (tree, wall, post), while 32.4% fell from the toboggan caused by environmental conditions such as a bump or a ditch. The most important risk factor was an unadjusted speed referred to the environmental circumstances. Preventive strategies include tobogganing in adequate environmental conditions with no trees, no post or other stationary objects that could result in a collision. Speed should be adapted to the slope conditions.

Acceleration↗
PubMed1998

A modular system for cemented and cementless implantation of femoral stem prostheses.

A femoral stem [BiContact, Aesculap, Germany) has been developed which is suitable for both cemented and uncemented implantation. Thus a highly standardized procedure and a standard implant for any iritraoperative finding is available. While the cemented stems have a smooth surface, the cementless implants are proximally coated with a microporous titanium plasmaspray [Plasmapore]. The strategy based on the intraoperative choice of the surgeon to use either cemented or cementless implants after bone preparation turned out to be very successful in our institution. A consecutive series of 250 cases with cemented implantation and 250 cases with uncemented implantation was analyzed in a prospective follow-up study, Pollow-up time averaged 7 years for cemented and 6.5 years for uncemented THRs. The follow-up rate was 88.7% in cases treated with cemented stems and 93.1% in cases treated with uncemented stems. The rate of aseptic loosening was 1.2% for the cemented version and 0.4-% for the uncemented stem. Radiological loosening could be observed in another 1.2% of the cemented stems and was not to be found in the uncemented cases. Our data suggest an excellent midterm stability of both the cemented and the uncemented version of the BiContact hip system. The long-term results for both the cemented and uncemented prostheses of our series are still to be evaluated.

Journal Article↗
PubMed1997

[Unreamed intramedullary nailing as minimal invasive palliative intervention in osteolysis and pathologic fractures of long tubular bones].

Pathological fractures and osteolyses with impending fractures of long bones impose a severe problem in patients with advanced cancer. For palliative treatment between June 1993 and October 1995 intramedullary nailing was performed in 19 patients with 13 femoral, 7 humeral and 1 tibial lesions; AO unreamed nails were used for this purpose (unreamed femur nail UFN with or with spiral blade for femoral lesions and unreamed tibia nail UTN for humeri and tibia). Stabilization was achieved without severe complications; full weight bearing of both femora and humeri (while using crutches) was allowed. Simultaneous and bilateral nailing was done. Follow-up until death due to advanced cancer demonstrated no implant failure and improved quality of life as well. Unreamed intramedullary nailing seems to be a minimally invasive procedure with a low complication rate for palliative treatment of (impending) pathological fractures in advanced cancer.

Adult↗
PubMed1997

Uncemented revision stem for biological osteosynthesis in periprosthetic femoral fractures.

Fractures around a femoral prosthesis have been treated with plating and additional cement, but this leads to further reduction of bone stock in the proximal femur. Since February 1992, we have dealt with this problem in 12 patients by revision using a long uncemented stem and distal interlocking combined with homologous bone grafting. Bony ingrowth and remodelling led to restoration of the proximal femur. After bone healing, removal of the distal interlocking screws converts the distal load transfer to the proximal anchoring of the revision stem so that osteointegration can occur in the trochanteric region. The clinical results were good in all the patients after a mean follow up of 23.5 months. This is a method which provides biological osteosynthesis and is especially indicated in younger patients.

Adult↗