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Biomedical subjects

K W Zilkens

Publications and source records attributed to K W Zilkens.

At least 19 recordsLinked to original sources
PubMed2001

Septic arthritis of the knee in adults: treatment by arthroscopy or arthrotomy.

Fifty-one patients with septic arthritis of the knee were reviewed retrospectively. Twenty-seven patients had been treated by arthroscopic lavage and debridement, 24 patients by open arthrotomy with subtotal synovectomy. The patients were staged according to the duration of preoperative symptoms and to the intraoperative spread of the inflammatory process. With early onset of therapy (less than 5 days) and without osseous involvement arthroscopic treatment led to an effective resolution of infection with better functional results than open arthrotomy.

Adult↗
PubMed2000

Interleukin-6: a potential inflammatory marker after total joint replacement.

In a prospective study C-reactive protein (CRP) and interleukin-6 (IL-6) measurements were taken serially in 30 patients before and after 20 total hip arthroplasties (THR) and 10 total knee arthroplasties (TKR). There were no peri- and postoperative complications. Postoperatively the IL-6 serum concentration increased rapidly and peaked 6 h postoperatively at maximum levels (399+/-140 pg/ml). There was a mean half-life of 15 h and thereafter a rapid return to normal concentrations. In comparison, the postoperative CRP concentration rose more slowly and reached maximum levels (138+/-54 mg/l) on the second postoperative day. There was thereafter a slow descent with a mean half-life of 62 h. There was no significant difference between the patients with THR and those with TKR (P>0.05). IL-6 is therefore a superior marker for the inflammatory phase after THR and TKR.

Aged↗
PubMed2000

Diagnostic and therapeutic management of lumbar and thoracic spondylodiscitis--an evaluation of 59 cases.

Fifty-nine patients with spondylodiscitis (SD) of the thoracic and/or lumbar spine were followed-up clinically and radiologically [X-ray, computed tomography (CT), magnetic resonance imaging (MRI)] over a mean time of 2.2 years (1-6.5 years). All patients without abscess formation (n = 35) were treated conservatively. Out of the group with abscess formation (n = 24) 6 patients were also treated conservatively, 11 were drained under CT control and 7 were operated. At time of diagnosis, "signs of florid inflammation" were seen in 60% of the roentgenograms, in 93% of the CTs and in all of the MRls. The sensitivity to differentiate between SD with and without abscess formation was 85% by MRI and 69% by CT. "Signs of regressive inflammation" and "signs of increasing osseous consolidation", essential facts for starting remobilization, could first be seen using CT 6 weeks after onset of therapy. Using MRI these signs were seen with a considerable delay at 12 weeks. Clinically, only 3 of the 59 analyzed patients developed recurrent SD. In conclusion, MRI is the radiological method of choice for establishing the diagnosis of SD, in particular with regard to differentiating between cases with and without abscess formations. In contrast, CT is superior for performing success control after treatment. Therapeutically, conservative, minimal-invasive and operative procedures are not rival but rather complementary.

Abscess↗
PubMed1998

[A new MR-(and CT-) compatible bone biopsy system: first clinical results].

PURPOSE: To describe the development and clinical evaluation of a new, hand-powered or alternatively motor-driven, MRI and CT compatible percutaneous bone biopsy system. MATERIALS AND METHODS: A new coaxial drill system (Cook Europe A/S) was designed for percutaneous, MR-guided bone biopsies and powered either by hand or an optional motor (10-250 rotations/minute using 6 bar [88.2 PSI] compressed air). The system has been used in 23 patients. Fourteen procedures were performed in a 1.5 T MR scanner (Philips-Gyroscan ACS-NT) which has an attached C-arm (Philips-BV 212-Angio) in case fluoroscopy is required, and 9 procedures in a CT scanner (Siemens-Somatom Plus). RESULTS: Driven by hand or by the pneumatic motor unit, the system achieved safe and accurate MR-guided access to all of the lesions and was even able to penetrate osteosclerotic lesions. MR- or CT-guided percutaneous biopsy yielded a correct diagnosis in all but 5 cases. No procedural complications occurred. CONCLUSION: MR-guided percutaneous bone biopsy performed with the new coaxial drill system was found to be safe and reliable, and suitable for obtaining histological specimens from skeletal lesions even when covered with thick cortical or sclerotic bone.

Biopsy↗
PubMed1997

Does the anchorage form and depth influence the pull-out strength of screws from bone cement? An experimental study.

The pull-out strengths of cortical screws inserted into soft, unpolymerised Refobacin Palacos bone cement (procedure S) and into hardened polymerised cement into which a hole had been drilled and tapped (procedure P) were compared. Cortical screws 58 mm in length, outer diameter 4.5 mm and inner diameter 2.95 mm were used. Screws were inserted into cement cylinders at 5 mm incremental depths between 10 and 30 mm. At a screw depth of less than 25 mm, the screws pulled out, and at a depth of greater than 25 mm, the screws broke in both procedures. There was no statistically significant difference in pull-out strength leading to burst or break between the two procedures for screws inserted to comparable depths, but there was a statistically significant difference regarding the screwing depth regardless of the procedure of screw insertion chosen. The average material stability (sigma) of the cortical screws used was calculated to be 1191 N/mm2, and the elasticity limit was 5137 N. This study demonstrated that the material stability and not the depth of screw insertion was the limiting parameter in screw anchorage in bone cement while static testing. To avoid screw breakage due to fatigue during continuous alternate loading, the screws should not be loaded above this value.

Analysis of Variance↗
PubMed1997

Anatomic study of femoral vein occlusion during simulated hip arthroplasty.

An anatomic study was undertaken to establish whether positioning of the leg and surgical approaches for total hip replacement (THR) cause changes in the femoral v. which may contribute to the development of deep vein thrombosis (DVT). The patency of 32 femoral vv. of 18 cadavers was inspected at different levels during simulated THR. Before and after removal of the femoral head through a transgluteal or posterior approach, a wide-angle endoscope was inserted into the femoral v. via the external iliac v. Blood flow was simulated by proximal irrigation with saline through the popliteal v. After removal of the femoral head distinct changes were observed in both approaches. In the transgluteal approach the changes were dependent on the degree of adduction and the body build of the cadaver. Initially, an oval form was seen in a constricted lumen with an increasingly oblique oval deformation and a final facet-like closure, usually at about 5 to 7.5 cm below the inguinal ligament. In total adduction this stenosis occurred regardless of build. Using a posterior approach, the necessary internal rotation caused a closure of the vein in 50% of cases. In combination with flexion and adduction there was stenosis in all cadavers regardless of body build. Our results indicate that the duration of the adducted position of the thigh during THR via a transgluteal approach should be minimised, as there is a reduction in blood flow with even minor degrees of adduction. In the posterior approach the stenosis occurs earlier, and is independent of the build of the cadaver.

Arthroplasty, Replacement, Hip↗
PubMed1996

Compound osteosynthesis of pathological fractures of the proximal femoral shaft. Experimental studies on the biomechanical effects of additional intramedullary splinting.

The biomechanical stability of two compound osteosynthesis techniques with and without intramedullary splinting were compared in 20 paired cadaver femora. Group A was stabilised using a contoured 12-hole DC plate and polymethylmethacrylate cement. In group B an additional intramedullary semi-diameter osteosynthesis plate was inserted parallel to the outer plate and transfixed with the same screws. The specimens were tested in a universal testing machine using a force applied to the specimen at 45 degrees to the load to provoke the most unfavourable condition, consisting of a bending moment and torsion. Both force and extension were recorded. The compound osteosynthesis with an additional intramedullary plate (group B) reached an average higher load stability. This increase of stability was not significant statistically.

Aged↗
PubMed1995

Reactivation of a tuberculous coxitis due to loosening of a total hip endoprosthesis.

A 45-year-old woman who suffered from juvenile tuberculous coxitis at the age of 4 is presented. Her hip joint replacement lasted for 18 years and then needed replacing. Intraoperatively removed caseous soft tissue and an opalescent secretion histologically resembled a tuberculous focus, and bacteriological culture grew a Mycobacterium tuberculosis strain. Four months after the replacement, the patient suffered from a tuberculosis-induced septic loosening of the newly replaced hip joint endoprosthesis. The tuberculosis relapse was probably due to aseptic loosening of the first hip joint endoprosthesis.

Female↗
PubMed1994

Osteocalcin levels in chronic osteomyelitis.

Osteocalcin is a vitamin K-dependent bone protein synthesized by osteoblasts. In generalized bone disorders serum osteocalcin correlates with osteoblast activity. Bone resorption and new bone formation occur in chronic osteomyelitis, dependent on the level of inflammatory activity. In 17 patients with active chronic osteomyelitis undergoing surgery, the serum levels of osteocalcin, alkaline phosphatase and C-reactive protein were measured before and after treatment. The osteocalcin levels were within the normal range preoperatively (10.8 +/- 11.0 micrograms/l), in the early postoperative period, and at discharge. It is therefore not a helpful marker in the clinical management of this condition.

Alkaline Phosphatase↗
PubMed1994

Pattern of macrophage subpopulations in post-traumatic bone infections after combined operative/antibiotic treatment.

Macrophage subpopulations were detected immunohistochemically with the aid of monoclonal antibodies in tissue sections of 15 patients with posttraumatic osteomyelitis at the beginning of therapy and after combined operative/antibiotic treatment. Macrophages represent the majority of the immunocompetent cells in osteomyelitis tissue. Before the start of therapy, the acute inflammatory macrophage subtype 27E10 was absent or rarely found in 8/13 evaluable biopsies from the osteomyelitis focus, and a further decrease in the expression of these macrophage antigens was observed after treatment. The RM3/1-positive macrophage associated with the down-regulation of inflammation was detectable to a low extent in 4/13 evaluable biopsies from the osteomyelitis focus before the start of therapy. After treatment of the infection, an increase in this subtype was found in the cellular inflammatory infiltrates in the tissue samples examined. In 8/15 biopsies a marked expression of the RM3/1 antigen was observed. At the start of treatment, the macrophage 25F9, which dominates in the late phase of inflammation, was missing in 3/13 tissue samples. After combined operative/antibiotic treatment the 25F9-positive macrophage was found in all patients, having increased in 7/14 biopsies studied. These data suggest that treatment of posttraumatic osteomyelitis leads to a local macrophage subtype distribution in the osteomyelitis focus resembling the pattern of a late inflammatory reaction.

Adolescent↗
PubMed1993

[Lymphocyte defects in chronic osteomyelitis. A prospective study].

In patients with chronic post-traumatic osteomyelitis, several deficits in immunological response were demonstrated. In a prospective trial of 20 patients with proven osteomyelitis, histological analysis of lymphocyte subsets in peripheral blood and in the infected bone tissue was performed. The effects of chronic osteomyelitis on lymphocyte subsets in the peripheral blood and in inflamed tissue were only slight. The T4/T8 ratio was diminished in only two patients and had no relationship to the clinical course. Interleukin 2 receptor determination was negative in 83% of biopsies of infected tissue. Osteomyelitis may possibly cause a defect in lymphocyte/macrophage cooperation.

Adolescent↗
PubMed1993

[Osteomyelitis today--diagnostic imaging and therapy].

Plain radiography, bone scan and especially in infants sonography belong to the primary imaging methods for posttraumatic osteomyelitis. For further diagnostic check up of osteomyelitis CT, MRI and leukocyte scintigraphy are excellent methods. Treatment of posttraumatic osteomyelitis is today a combination of operation, local and systemic antibiotic therapy.

Adolescent↗
PubMed1992

[Treatment of osteomyelitis and reconstructive measures in patients with war injuries].

54 wartime trauma patients injured by bombs, shell splinters or rockets were treated between 1985 and 1989 in the Orthopaedic Clinic of RWTH Aachen. Lesions of the lower limbs were dominating (78%). Treatment was often tedious, and up to 12 operations had to be performed. In 81% one extremity was injured, in 17% two extremities were involved. 78% of the patients were already primarily treated at home, mostly by amputations. 33% of the patients suffered from bone infections at admission. Infections were mostly caused by Staphylococcus aureus or Pseudomonas aeruginosa. In 41% of all patients operative treatment for osteomyelitis was necessary (37% sequesterectomies, 44% stabilisations with fixateur externe). In advanced bone infection amputations were indispensable in 28%. In 27% of our wartime trauma patients reconstructive surgery was performed (spongiosa transplantations in 91%, stabilisation with fixateur externe in 44%). In none of our patients treated with reconstructive surgery an amputation was necessary later on.

Adult↗
PubMed1991

[PMN-elastase as a marker in diagnosis and follow-up of bone and joint infections].

PMN elastase, a proteolytic enzyme, is a biochemical marker for pathologic granulocyte stimulation. In the presence of sepsis, excessive neutrophil stimulation occurs and significant amounts of PMN elastase are released into the plasma and serve as an indicator for the severity of the disease and the prognosis. PMN elastase is also a useful parameter for preoperative diagnostic management and postoperative follow-up of bone and joint infections. In patients with osteomyelitis and joint empyema (n = 48) PMN elastase had a sensitivity of 77%, which was only exceeded by that of the unspecific erythrocyte sedimentation rate (sensitivity 89%). Sensitivities of other inflammation parameters were lower: C-reactive protein (CRP) 67%, fibrinogen 50%, neopterin 32% and leukocyte count 21%. Determination of PMN elastase levels was also helpful in postoperative follow-up of patients with bone and joint infections. In the early postoperative period PMN elastase levels normalized more quickly than the other parameters unless patients actually developed complications. At the first postoperative determination (day 2-4 after surgery) 38% of the patients (n = 24) already had PMN elastase levels within the normal range (less than or equal to 40 micrograms/l) (CRP 13%). After 10 days PMN elastase was normal in 57% and CRP in 30% of the patients. Later on both parameters reacted similarly: by the time of discharge from hospital levels of PMN elastase were normal in 70% and CRP levels in 74%.

Acute-Phase Proteins↗
PubMed1990

Influence of bone and soft-tissue operations on serum concentrations of growth hormone, somatomedin C and alkaline phosphatase.

After animal experiments suggested there was an interaction between growth hormone and bone healing, our aim in this paper was to ascertain whether there were any changes or possible interaction between the serum level of growth hormone, somatomedin C and alkaline phosphatase while a fractured bone was healing. To this end, the serum concentrations of growth hormone, somatomedin C, alkaline phosphatase and calcium were ascertained both pre- and post-operatively in two groups of patients--one with bone operations, the other with soft-tissue operations--and the results were compared. Comparing the groups, we found that after bone operations there was no increase in the serum level of growth hormone, nor of somatomedin C. An increase would have implied that these two hormones are directly involved in bone regeneration. There was no change in the serum level of alkaline phosphatase or calcium after either bone or soft-tissue operations.

Adolescent↗
PubMed1989

[Treatment of infected total hip endoprostheses].

In total hip arthroplasty the most serious complication besides aseptic loosening is infection. The results observed in 42 cases of infected hip arthroplasties are presented. In contrast to early superficial infection, deep infection following total hip replacement is difficult to treat. Depending on the general condition of the patient, a well-defined, adequate treatment is required. In patients at vital risk the provocation of a permanent fistula can be recommended as an alternative method in preference to revision arthroplasty.

Aged↗
PubMed1988

Nuclear imaging in loosening of hip-joint endoprostheses.

In 28 patients with surgically proved loosening of hip-joint endoprostheses and 42 patients without loosening between 2 and 12 years after implantation and without clinical or radiological signs of loosening we performed clinical evaluation, and radiographs, a three-phase bone scan, and a 111indium-labeled leukocyte scan (ILLS). The sensitivity of radiographs in the group with loosening of hip-joint endoprostheses in the femoral as well as in the acetabular component was only about 50%, while the specificity was almost 100%. With a combination of radiographs and ILLS we reached a sensitivity in the acetabular component of 100% and in the femoral component of 88%, but specificities of only 57% in the acetabular component and 40% in the femoral component were found. We found that the ILLS is a very helpful method of examination to detect loosening of hip-joint arthroplasties in doubtful cases.

Hip Joint↗