Biomedical subjects

C H Siebert

Publications and source records attributed to C H Siebert.

At least 19 recordsLinked to original sources

PubMed2006

[Revision surgery for knee prostheses using the DRG system].

Due to an increasing life expectancy and earlier primary implantation of total knee replacements, the number of patients requiring revision surgery in Germany is increasing by 7% every year. These revision cases belong to the most treatment and cost intensive operations in joint replacement surgery. Presently, the description of these procedures in the German DRG system, which defines the financial reimbursement for the hospitals, is changing yearly with the development of new catalogues. The changes made from 2003 to 2005 are outlined in the following article. A correct depiction of the treatment and procedures required in such cases is a prerequisite for an adequate reimbursement. In the long-term, hospitals will only be able to offer such complex treatment forms if the financial compensation correctly reflects the costs incurred.

Arthroplasty, Replacement, Knee↗

PubMed2004

Anatomical and biomechanical investigations of the iliotibial tract.

Divergent descriptions of the anatomic location and biomechanical function of the iliotibial tract (IT) can be found in the literature. This study attempted to obtain exact data regarding the anatomic course and material characteristics including the biomechanical properties of this structure. The following were its aims: (1) anatomical investigations of the IT; (2) mechanical properties of the IT; (3) femoral head centralizing force of the IT and subligamentous forces in the height of the greater trochanter in different joint positions by using a custom-made measuring prosthesis and a subligamentous positioned sensor; (4) construction of a finite element model of the proximal femur including the IT and measuring the femoral neck angle under variation. The hip joints and IT in a total of 18 unfixed corpses were evaluated. We studied the anatomic relationship to surrounding structures, as well as the material properties with the help of tensile strength testing utilizing an uniaxial apparatus. During the test, a load-displacement curve was registered, documenting the maximum load and deformation of the IT. To measure the subligamentous pressure at the height of the greater trochanter, a custom-made sensor with a power-recording instrument was constructed. Furthermore, an altered hip prosthesis with a pressure gauge at the height of the femoral neck was used to measure the forces which are directed at the acetabulum. The investigations were done in neutral-0 position and ab/adduction of the hip joint of the unfixed corpse. In addition, we varied the femoral neck angle between 115 degrees and 155 degrees in 5 degrees steps. To confirm the subligamentous forces, we did the same measurements intraoperatively at the height of the greater trochanter before and after hip joint replacement in 12 patients. We constructed a finite element model of the proximal femur and considering the IT. The acquisition of the data was done at physiological (128 degrees), varus (115 degrees), and valgus (155 degrees) femoral neck angles. The influencing forces of the IT at the height of the greater trochanter and the forces at the femoral head or the acetabulum could be measured. Our anatomical investigations revealed a splitting of the IT into a superficial and a deep portion, which covers the tensor fasciae latae. The tensor fasciae latae has an insertion on the IT. The IT continues down the femur, passing over the greater trochanter without developing an actual fixation to the bone. Part of the insertion of the gluteus maximus radiates into the IT. The IT passes over the vastus lateralis and inserts at the infracondylar tubercle of the tibia or Gerdy's tubercle, at the head of the fibula, as well as at the lateral intermuscular septum. Portions also insert on the transverse and longitudinal retinaculum of the patella. Concerning the material properties of the IT, we found a structural stiffness of 17 N/mm extension on average (D = 17 N/mm). The subligamentous measurements at the height of the greater trochanter in the unfixed corpse and intraoperatively during hip joint replacement showed an increase of the forces during adduction and a decrease during abduction of the hip joint. We found thereby a maximum increase up to 106 N with 40 degrees adduction. Concerning the femoral neck angle, we can state that valgus leads to lower subligamentous forces and varus to higher subligamentous forces. The forces directed at the acetabulum, which were measured by the prosthesis with a sensor along the femoral neck, showed a decrease with varus angles and an increase with valgus angles. The highest force of 624 N was measured with 40 degrees adduction and an angle of 155 degrees. The finite element model of the proximal femur showed a sole hip joint-centralizing force of the IT of 655 N with a femoral neck angle of 128 degrees after subtraction of the gluteal muscle force and the body weight. At 115 degrees, we found an increase up to 997 N and a decrease to 438 N at 155 degrees. Concerning the resulting forces in the acetabulum, we found opposite forces in comparison with the force of the IT at the height of the greater trochanter: at 115 degrees, a femoral head-centralizing force of 1601 N; at 128 degrees, 2360 N; and at 155 degrees, 2422 N. By our investigations, we can approximately prove the hip joint-centralizing force of the IT. By variation of the femoral neck angle and the position of the hip joint, we can predict the subligamentous force of the IT and the resulting force at the femoral head or at the acetabulum. The intraoperative measurement of the subligamentous forces of the IT is a good monitoring mechanism for the persistent hip-centralizing function of the IT in the course of hip joint replacement. The surgeon has the opportunity to check the stability of the hip joint after replacement. The finite element model gives the opportunity to check the divergent relative strength by variation of the femoral neck angle and the tension of the IT. In this way, the changes in the forces induced by a displacement osteotomy could be estimated preoperatively.

Aged↗

PubMed2003

Reactive knee and ankle joint arthritis: abnormal manifestation of Legionella pneumophila.

This case report demonstrates that active legionellosis is not always characterised by pulmonary symptoms and specific radiomorphological findings. Whereas the initial clinical presentation, as described in the literature, includes fever, cough, expectoration, extrapulmonary organ changes or typical laboratory findings, atypical manifestations such as reactive arthritis must be considered.

Adult↗

PubMed2003

Patellar hypertension syndrome in adolescence: a three-year follow up.

INTRODUCTION: Anterior knee pain is one of the major causes of knee pain in an adolescent population. It has been suggested that raised intraosseous pressure may play an important role in the development of anterior knee pain in the young patient. MATERIAL AND METHODS: A prospective clinical multicentre study with 27 adolescent patients presenting with anterior knee pain was performed. After failure to respond to conservative treatment, all patients agreed to undergo minimally invasive intraosseous pressure measurements in local anaesthesia. All 27 patients demonstrated a positive "pain provocation test" as a response to increased intrapatellar pressure and were decompressed with a new intraosseous drilling technique. RESULTS: The repeat intraosseous pressure measurement in 27 patients 1 year postoperatively revealed a significant reduction from 43.3+/-13.4 preoperatively to 24.1+/-4.2 mmHg (p<0.001). The pain relief was documented in the form of a reduced VAS from 7.6+/-1.4 to 2.1+/-1.1 cm after 3 years (p<0.001). CONCLUSION: Patients with anterior knee pain and a positive "pain provocation test" were diagnosed as suffering from a hypertension syndrome of the patella. We conclude that simple extraarticular patellar decompression may offer a valuable new form of treatment in this select group of adolescent patients with anterior knee pain.

Arthralgia↗

PubMed2003

Transient osteoporosis of the navicular bone in a runner.

INTRODUCTION: Transient osteoporosis or the bone marrow oedema syndrome is described as a self-limiting disorder. Transient osteoporosis usually affects only one bone, predominantly the proximal femur. Involvement of the foot is rare and often overlooked. A disorder of the navicular bone of the foot can be found twice in the literature. MATERIALS AND METHODS: We report a case of transient osteoporosis of the navicular bone of the foot in a 20-year-old, female, top-level track athlete (400 m sprinter) treated with alendronate, and a review of the literature. RESULTS: The therapeutic options are limited, frequently consisting of non-specific, symptomatic therapy. Some authors report favourable results with core decompression, while others have reported good results with a conservative regime of symptomatic treatment and avoidance of weight-bearing until the clinical and radiological changes have resolved. In the described case, the patient had a favourable result after a short course of treatment with alendronate. She experienced almost immediate pain reduction and presented a complete resolution of the abnormal signal intensity on MRI. CONCLUSION: This rapid result makes the use of alendronate seem promising in athletes with transient osteoporosis, permitting an early return to high-level activities.

Adult↗

PubMed2003

[Proposals for adapting a DRG system in the fields of orthopedics and trauma surgery for 2004].

The introduction of the DRG system in Germany-optional since 1 January 2003 and mandatory for all hospitals as of 1 January 2004-has resulted in great uncertainty, particularly on the part of hospitals, since apprehension prevails that the diagnostic and therapeutic measures practiced in Germany will not be appropriately represented and remunerated by a DRG system. The G-DRG version 1.0 prepared within the framework of substitutive execution is largely identical to the Australian AR-DRG version 4.1. Adjustments that do justice to the realities of German treatment modalities were at most insignificant. It is therefore essential that stock be taken for each medical specialty to determine to what extent treatment procedures commonly followed in Germany are adequately reflected in this G-DRG system or whether adjustments are necessary to make allowances for German realities. To be able to provide qualified statements on the problems involved, scientific analysis of possible problems is necessary utilizing German data. Thus, we undertook an evaluation of how the special fields of orthopedics and accident surgery are represented in the G-DRG system. The resultant data form the basis for evidence of presumable deficits in the representation of orthopedic and accident surgery cases in the G-DRG system. The German Association for Trauma Surgery and the German Association for Orthopedics and Orthopedic Surgery have undertaken a DRG evaluation project together with the Organization of Directors for Accident Surgery (chairperson: Professor Dr. Mischkowsky, Kempten), the Organization of Directors for Orthopedics (chairperson: Professor Dr. Puhl, Ulm), the DRG Working Group of the German Association for Accident Surgery, and the Joint Commission of the Professional Association of German Surgeons and the German Association for Surgery in cooperation with the DRG Research Group of the University Clinic Muenster, the German Hospital Association, and the German Medical Association with the goal of examining the medical and economic homogeneity of the case groups. A total of 12,645 orthopedic and trauma surgery cases were collected from 23 clinics-11 university hospitals and 12 non-university hospitals-and assessed. On the basis of this database and when too few cases were evaluable also based on clinical considerations, 14 adjustment proposals were formulated and submitted on schedule on 31 March 2003 to the Institute for Hospital Remuneration. The results of the DRG evaluation project illustrated the problems involved in representing the exceedingly heterogeneous and complex activities of orthopedic and trauma surgery departments in a flat rate financing system that is not attuned to the realties of German treatment procedures. Version 1.0 of the G-DRG system is not sufficiently differentiated to represent the multifaceted diagnostic and therapeutic services provided by trauma surgery and orthopedic departments in Germany.

Diagnosis-Related Groups↗

PubMed2002

Use of extracorporeal shock-wave therapy (ESWT) in the treatment of non-unions. A review of the literature.

Presently, extracorporeal shock-wave therapy (ESWT) is not yet a standard therapeutic technique in orthopaedics. The mechanism for the analgesic effect or the effect of shock waves on osseous defects are still unknown. With the help of a review of the literature, indications and success rates for ESWT in the treatment of non-unions are outlined, while adequate impulse and energy rates are defined according to the present state of knowledge. Non-union is defined as an absent healing process after a duration of 6 months. The aim of this study is to rate the published data. A total of 52 papers referring to ESWT of the locomotor system are reviewed, with a focus on the 635 patients from 10 publications who underwent ESWT to treat non-unions. Validation was performed for each paper dealing with this topic according to the internationally accepted system of the American Association of Spine Surgery as types A-E. Conclusions regarding possible applications in therapy were taken only from high-quality publications of types A and B. This advice can be regarded as scientifically as well as economically sound. The investigations concerning non-union hardly live up to scientific standards. No serious complications were observed. Because of the complication rate in operative treatment of non-unions, ESWT seems to be justifiable. The techniques of ESWT, energy density levels and impulse rates will be described. Atrophic non-unions seem to represent a poorer starting point in comparison with hypertrophic non-unions. Most investigations showed a consolidation of the non-union during a period of 3 months following ESWT, so that in case of treatment failure, operative treatment in the form of a re-osteosynthesis would only be delayed for this period of time. The advantages of ESWT are its non-invasiveness and low rate of complications. The primary aim of further research should be the evaluation of adequate energy density levels and impulse rates for various indications in accordance with evidence-based medicine. Long-term results need to become available before ESWT can be compared with established methods.

Animals↗

PubMed2002

Efficacy of intraarticular hyaluronic acid in patients with osteoarthritis--a prospective clinical trial.

AIM: The goal of this study was to determine whether or not the intraarticular administration of hyaluronic acid can improve functional parameters, such as isokinetic muscle strength or total work and clinical test results in patients with osteoarthritis (OA) of the knee. METHOD: As part of a prospective, controlled study 43 patients with osteoarthritic changes of both knees (radiographic Kellgren stage II-III) were followed in a right/left comparison. The influence of intraarticularly injected hyaluronic acid (20mg hyaluronic acid/2ml Hyalart) on functional and clinical parameters was analysed. We used the isokinetic system Cybex 600 for measuring maximal isokinetic muscle strength and total work. A total of 20 males and 23 females fulfilled the inclusion criteria with an age between 55-78 years and underwent five injections of hyaluronic acid (one injection per week). The injected knee represented the treatment group, while the contralateral knee served as the control. RESULTS: The maximum peak torque of the knee extensors in the treatment group was measured between 57+/-26.15/32.33+/-19.63Nm prior to the injections and 77.17+/-32.54/47.83+/-21.43Nm following the hyaluronic acid therapy (P< 0.01). The analysis of the knee flexors at angular velocities of 60 degrees /s and 180 degrees /s revealed values of 40.44+/-21.58/22.89+/-16.64Nm and 53.55+/-24.26/34.05+/-17.37Nm (P< 0.01) respectively. The evaluation of the total work of the knee flexors and extensors revealed a significant difference (P< 0.01) between the treatment and control group. The Lequesne score was reduced from 13.57+/-1.88 prior to the injections to 7.94+/-2.53 after the treatment (P< 0.01). The pain score was documented with the help of a visual analog scale. The VAS values were reduced at rest from 3.83+/-1.72cm to 1.36+/-1.42cm and during weight bearing from 7.57+/-1.34cm to 3.75+/-1.32cm in the treatment group (P< 0.01). CONCLUSIONS: This controlled prospective clinical trial confirmed that 5 weekly intraarticular injections of HA (Hyalart) in patients with OA of the knee provide pain relief and functional improvements.

Aged↗

PubMed2002

Recurrent focal myositis of the peroneal muscles.

Recurrent focal myositis is a rare entity and can be difficult to diagnose and treat. A long-term follow-up and diagnostic evaluation was carried out in a patient who presented with ankle stiffness secondary to a painful mass within the calf. This process was diagnosed as focal myositis of the peroneal muscles, which recurred over a period of 7 yr. A review of the literature regarding focal myositis, treatment options and a successful conservative therapy regimen, as an alternative to a surgical protocol, are presented. After making the diagnosis with the help of a muscle biopsy, long-term therapy should be considered. Conservative treatment of focal myositis with anti-inflammatory drugs and physical therapy can be successful but recurrence may occur if the medical treatment is interrupted.

Adult↗

PubMed2001

In vivo testing of a new in situ setting beta-tricalcium phosphate cement for osseous reconstruction.

A new in situ setting tricalcium phosphate cement was implanted in 1.5-mm trepanation defects in rat femurs. Empty cavities and autologous bone grafts were used as controls. Cement resorption and new bone formation were evaluated in undecalcified sections with histologic examination, contact microradiographies, radiodensitometry, and scanning electron microscopy after 1 and 3 weeks. The mechanical integrity was tested in a three-point bending test. The amount of new bone formation over time was determined by intravital fluorescence staining. With the in situ setting substance, a good filling of the whole trepanation defect was achieved without leakage of the paste-like cement. Slow resorption of the cement and new bone formation beginning at the edge of the defect were seen after 1 week. After 3 weeks, resorption was advanced and there was ingrowth of new bone, with close contact between cement particles and bone, as shown in histologic sections and with a calcium/phosphorus analysis by quantitative line scans of an electron microanalysis (SEM-EPMA). This new self-hardening cement is bioactive, resorbable, and osteotransductive. It may be usable for the filling of stable defects, such as cysts or benign tumors, or for bone supplementation in revision arthroplasty.

Animals↗

PubMed2001

Correction of kyphotic deformity before and after transection of the anterior longitudinal ligament--a cadaver study.

With a custom-made measuring unit, two separate experiments, involving six and five cadaveric torsos with intact rib cages and sternums, respectively, were carried out to determine the effect of the transection of the anterior longitudinal ligament with and without osteodiscectomy and its influence on the thoracic kyphosis. The open or thoracoscopically assisted anterior release, as part of the operative treatment of scoliosis or kyphosis, usually consists of a transection of the anterior longitudinal ligament (ALL) and an additional discectomy. A complete osteodiscectomy, however, is not always possible with a minimally invasive approach. As part of our biomechanical research, we attempted to quantify the amount of correction achievable with a defined force prior to and following the isolated transection of the anterior longitudinal ligament. The aim of the study was to clarify whether or not an isolated transection of the anterior longitudinal ligament is sufficient to obtain an adequate anterior release of the spine. In the surgical treatment of kyphotic deformities, anterior release of the spine is performed in the form of a transection of the ALL and discectomy. Recently, video-assisted thoracic surgery has become increasingly popular in spine surgery. As part of this change in surgical technique, the question has arisen as to what extent an isolated transection of the ALL provides an adequate release of the thoracic spine. Eleven human spines were retrieved from fresh cadavers, dissected, and attached to a specially constructed apparatus. The spine was attached to the construct at the twelfth vertebral body. C6 and C7 were fixed in synthetic resin. We installed the instruments in such a manner as to reproducibly apply a torsional moment of 10 Nm to the spine. Motion was only permitted in the sagittal plane. Segmental transections of the ALL were carried out from T3 to T7. For comparison, the sagittal Cobb angle was also documented following an anterior release combined with an osteodiscectomy. With the isolated transection of the ALL, an average correction of the sagittal Cobb angle of 4 degrees in each functional spinal motion segment was recorded. In comparison, the additional osteodiscectomy led to a further average increase of only 2 degrees per level. The measurements performed on human cadavers showed that the isolated transection of the ALL leads to a sufficient anterior release of the thoracic spine, allowing a correction of the kyphotic deformity. The release with a concomitant osteodiscectomy represents a more time-consuming and more invasive procedure resulting in only a slightly greater amelioration of the sagittal Cobb angle, while being associated with a greater patient morbidity.

Aged↗

PubMed2001

Deep soft-tissue leiomyoma of the popliteal fossa in a 14-year-old girl.

This is the first case report of a deep soft-tissue leiomyoma with intraarticular localization within the knee joint. A 14-year-old girl presented with a painless mass in the dorsal aspect of her knee which she had noticed some 9 months earlier. While on plain radiographs no bony lesions were visible, magnetic resonance imaging (MRI) revealed an intraarticularly located tumor with well-defined margins. Intraoperatively, the tumor was found adjacent to the posterior cruciate ligament. The final diagnosis was established immunohistologically. Although this is a very rare tumor, it has to be considered in the differential diagnosis for soft-tissue swellings of the popliteal fossa.

Adolescent↗

PubMed2001

Spinal stabilization in Duchenne muscular dystrophy: principles of treatment and record of 31 operative treated cases.

The aim of this study was to report results of prophylactic spinal stabilization in patients with Duchenne muscular dystrophy. There is still debate regarding the ideal instrumentation. A prospective study of a consecutive series of 31 patients stabilized with the ISOLA system from D2 to S1 will be presented. The mean follow-up was 22 months (range, 1-60 months). The evaluation of the Cobb angle and pelvic obliquity revealed the following: 1) Cobb angle: preoperation, 48.6 degrees (range, 22-82 degrees); postoperation, 12.5 degrees (range, 0-30 degrees); follow-up, 12.5 degrees (range, 0-42 degrees); and 2) pelvic obliquity: preoperation, 18.2 degrees (range, 3-40 degrees); postoperation, 3.8 degrees (range, 0-13 degrees); follow-up, 5.1 degrees (range, 0-14 degrees). Spinal stabilization with the ISOLA system was found to be a suitable treatment for scoliosis owing to Duchenne muscular dystrophy. It should be carried out after loss of ambulation as soon as a progressive curve of more than 20 degrees is documented. The complication rate was found to be high.

Adolescent↗

PubMed2000

Thoracoscopically assisted ligamentous release of the thoracic spine: a cadaver study.

The surgical treatment of thoracic kyphosis frequently requires an anterior release, which can be carried out by an open or endoscopic technique. This study concerns the reference points which are essential from the anatomic view for minimizing the operative risks. Furthermore we wanted to find the most convenient video-assisted thoracoscopic surgery (VATS) technique for transection of the anterior longitudinal ligament (ALL). Transection of the ALL, as well as discectomy, was performed using this technique. The extensive anatomic dissection of 12 fresh cadavers was performed to define possible technical errors and surgical complications. The development of new instruments has made the VATS approach to the ALL a viable alternative to open procedures. With the help of a standardized technique, the isolated thoracoscopic ligamentous transection required less time than the comparable open procedure. The anatomic study showed, that in no case was a ligation of the intercostal or segmental vessels necessary as part of the approach to the spine, once an adequate mobilization of the esophagus and azygos vein had been carried out. The risk of an ischemic lesion of the spinal cord was thereby reduced. The thoracoscopic, limited anterior release consisting of a multilevel transection of the ALL proved to be a rapid and reliable procedure. Our anatomic studies provides suitable the reference points.

Adult↗

PubMed2000

Bilateral total hip replacement in pseudoachondroplasia.

Pseudoachondroplasia is an inherited skeletal dysplasia with short-limbed dwarfism and early onset of osteoarthritis. A 29-year-old pseudoachondroplastic woman presented with progressively painful hips secondary to severe osteoarthritis of both joints, so that total joint replacements were necessary to restore her mobility and quality of life. The implants inserted had to be specifically manufactured in accordance with the individual geometry and reduced bone size. In addition, the implants mechanical resistance to dynamic loading conditions had to be tested prior to total hip replacement surgery.

Adult↗

PubMed1999

[Focus debridement of chronic sequestered talus osteomyelitis by TCNC arthrodesis. A new technique with ring fixateur].

A technique utilizing the Ilizarov ring fixator to stabilize a tibio-calcaneo-naviculo-cuboideal arthrodesis following talus resection is introduced. The advantages of this method will be demonstrated with the help of a case history. The described method permits early weight bearing, while supplying stability and compression of the fusion, thereby avoiding further loss of bone stock, while reducing the risk of thromboembolic complications. The Ilizarov ring fixator construction allows for the combination of the fusion with the correction of a preexisting or ensueing leg length discrepancy.

Adolescent↗

PubMed1999

Late results after arthroscopic partial medial meniscectomy.

In a retrospective study, 100 patients underwent a clinical and radiological follow-up examination after a minimum of 7 years (range 7.0-9.3 years) following an arthroscopic partial medial meniscectomy. None of these patients had associated intra-articular lesions, apart from minor chondral damage (max. grade 2 Outerbridge classification; < 1 cm2) of the medial compartment at the time of the primary arthroscopy. According to the modified Marshall score, the follow-up evaluation showed excellent clinical results in 96%. Nevertheless, the radiological outcome, as measured by comparing preoperative and postoperative X-rays, demonstrated a development or progression of the osteoarthritis of the affected knee joint in 33%, with a statistically significant correlation between the radiological and clinical outcomes (P < 0.05). The age of the patients at the time of operation and any angular deformity of the knee joint did not influence the radiological results. Women had a statistically significantly higher risk of developing gonarthrosis after partial medial meniscectomy than men (P < 0.05). The arthroscopic partial medial meniscectomy led to excellent subjective and functional results but could not prevent the increase or development of late degenerative changes in the medial knee compartment.

Adolescent↗

PubMed1999

The quadriceps tendon cyst: an uncommon cause of chronic anterior knee pain.

The causes of knee pain are manifold. One of the uncommon causes of chronic anterior knee pain are cysts and ganglia. Magnetic resonance imaging not only reveals the intra-articular pathology but also accurately depicts such cystic structures about the knee. As part of this case report, a cyst of the lateral border of the quadriceps tendon is presented as a cause of such discomfort. Although cystic lesions around the knee are a common clinical problem, the described location is rare. After surgical revision of the lateral border of the quadriceps tendon and excision of the cyst, the patient was found to be asymptomatic.

Adult↗