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T Krackhardt

Publications and source records attributed to T Krackhardt.

8 recordsLinked to original sources
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

Effect of human platelet supernatant on proliferation and matrix synthesis of human articular chondrocytes in monolayer and three-dimensional alginate cultures.

Articular cartilage is rich in collagen type II fibres and proteoglycans and is characterized by low cell density. Chondrocytes have specific nutritional requirements and therefore cannot be expanded in vitro without the risk of generating fibroblastoid cells expressing type I collagen. Therefore, various growth conditions were tested for cartilage tissue engineering. Human platelets are a rich source of many growth factors including transforming growth factor-beta and platelet-derived growth factor. To investigate the effect of human platelet supernatant (hPS) on chondrocyte proliferation and differentiation, human articular biopsies obtained from three healthy donors. Chondrocytes were isolated and expanded separately in monolayer cultures and seeded in alginate beads in the presence and absence of hPS of 1% or 10% v/v concentration. Transcript levels of genes encoding chondrogenic factors were determined by quantitative reverse transcriptase-polymerase chain reaction. The deposition of types I and II collagen as well as proteoglycan was detected by indirect immunocytochemistry. Addition of hPS activated chondrocyte proliferation in monolayer cultures but induced a dedifferentiation of chondrocytes towards a fibroblast-like phenotype. The expression levels of mRNAs encoding type II collagen, aggrecan and bone morphogenetic protein-2 were reduced in all samples tested. Seeding chondrocytes in alginate beads in the presence of hPS generated a cell population capable of type II collagen expression, even though hPS induced considerable type I collagen expression as well. Differences (1% vs. 10% group, 1% vs. control, 10% vs. control) in the quantitative gene expression of types I and II collagen or of aggrecan were statistically significant (p<0.001). We conclude that addition of hPS may accelerate chondrocyte expansion but can lead to their dedifferentiation.

Adult↗
PubMed2004

[Direct CT-arthrography versus direct MR-arthrography in chronic shoulder instability: comparison of modalities after the introduction of multidetector-CT technology].

PURPOSE: To evaluate the diagnostic accuracy of direct multidetector CT arthrography (CTA) and direct MR arthrography (MRA) in patients suffering from chronic shoulder instability. MATERIALS AND METHODS: Twenty-nine patients suffering from chronic shoulder instability were included into a prospective study. In all cases, the indication for direct CTA and arthroscopy was set by the orthopedic surgeon. Prior to the imaging procedures, 10 to 20 ml of a special combination of contrast media (including saline, Isovist(R) and Magnevist(R) in a relation of 125 : 125 : 1) was injected into the joint under sterile conditions. First, CTA was performed with a multidetector CT, with images reconstructed in the axial, semi-coronal and semi-sagittal planes. Thereafter, MRA was performed. Axial images were obtained using a T1-weighted, fat-saturated spin echo sequence and semi-coronal images using a T1-weighted FLASH-3D GRE sequence. The results of CTA and MTA were compared with results obtained from arthroscopy or arthrotomy. RESULTS: MRA was superior to CTA in the detection of labral lesions. The sensitivity of MRA was 96 % and the specificity 96 %, compared to a sensitivity of 76 % (p < 0.05) and specificity of 92 % for CTA. Both methods showed the same effectiveness concerning the assessment of capsule distension (sensitivity for both techniques: 91 %). CONCLUSIONS: MRA seems to be superior to CTA in the diagnostic workup of chronic shoulder instability even when using a multidetector CT technique.

Adolescent↗
PubMed2002

[MRI of intraosseous fistulous systems and sequesters in chronic osteomyelitis with standard spin echo sequences, highly selective chemical-shift imaging, diffusion weighted imaging, and magnetization-transfer].

PURPOSE: To study and test the impact of modern MRI techniques in diagnostic imaging in the evaluation of intra-osseous fistulous systems and sequesters. MATERIALS AND METHODS: In a prospective study, nine patients with chronic osteomyelitis of the legs were examined by MRI. Patients with clinical signs of osteomyelitis requiring surgery were included in the study. T1-weighted spin echo (SE) sequences, proton density (PD) and T2-weighted fast spin echo (FSE) sequences, water- and fat-selective FSE sequences, and diffusion weighted (DW) PSIF sequences were used preoperatively. Furthermore, magnetizing transfer (MT) with gradient echo (GRE) sequences was evaluated. RESULTS: Water selective sequences revealed the highest sensitivity for the detection of fistulas (100%), providing the best delineation of the extent of the entire fistulous systems. Fat-selective sequences (sensitivity 55.6%) and T1-weighted sequences (sensitivity 77.8%) displayed fistulas as hypointense bands, which, however, cannot be well differentiated from cortical bone in the transcortical areas. PD and T2-weighted images were found to have a poor sensitivity (55.6% and 66.7%) for fistulas in any location. The sensitivity of water-selective sequences to demonstrate intraosseous sequesters was 100%. The sensitivity was low for the other sequences. In 4 of 5 patients with surgically proven infection, DW and MT revealed an abnormal spatial distribution, with high diffusion in the central parts of the fistulas and high MT effect peripherally surrounding a weak MT effect centrally. CONCLUSION: Water-selective sequences are superior when demonstrating fistulous systems and intraosseous sequesters. The combined use of MT and DW sequences seems to allow a differentiation between solid granulation tissue and liquid pus.

Adult↗
PubMed1997

[Injuries due to inline skating].

In order to elucidate the patterns of injuries associated with in-line skating all patients with a inlineskate injury have been sampled prospectively during summer 1996. 58 patients were included in the study, aged 8 to 54 years (mean 22.2 years). The total number of injuries was 63, that is 1.1 injury in every injured skater. The upper extremity was the region most commonly injured (63.5%), with the distal radius fracture being the most common single fracture (25.4%). The most severe injuries, however, could be found in the lower extremity, including two femoral neck fractures and one pertrochanteric fracture in three patients aged more than 35 years. 22.4% of patients required hospitalization up to 54 days, and 36.2% of injuries had to be treated operatively. The most common single procedure was closed reduction and percutaneous wire fixation of displaced radius fractures. It is concluded that in-line skating imposes a risk of severe injuries especially on first-time skaters aged 35 years and up. The typical skating injury is the fracture of the wrist, a fact pointing out the necessity of the use of appropriate safety gear.

Adolescent↗
PubMedDate not supplied

[Indications and implementation of recommendations of the working group "Tissue Regeneration and Tissue Substitutes" for autologous chondrocyte transplantation (ACT)].

For the treatment of full-thickness articular cartilage lesions of the knee joint, as a result of trauma or osteochondritis dissecans, a variety of biological reconstruction techniques have been developed. Different studies, some of which were performed as randomised, prospective clinical studies, showed that the autologous chondrocyte transplantation (ACT) provides the most satisfying and reliable method of cartilage reconstruction in the adult when applied to defects exceeding 4 cm (2). Based on these results, ACT seems to be of economic benefit, as the risk of developing osteoarthritis correlates significantly with the size of the cartilage defect, when not treated properly and in time. Surveying the studies on basic scientific aspects of ACT, cartilage defect animal models and clinical studies, it can be concluded that clinical results of ACT depend on a variety of factors. In this review, published by the joined advisory board of the German Societies of Traumatology (DGU) and Orthopaedic Surgery (DGOOC), we summarize the current knowledge available and the state of the art concerning ACT. Especially we discuss the advantages of different procedures, methods for treating knee cartilage defects and factors that influence the outcome of the different treatment regimens, with the aim to develop guidelines for the correct indication and application of the ACT.

Adult↗