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Biomedical subjects

R Krauspe

Publications and source records attributed to R Krauspe.

At least 55 records · Page 3Linked to original sources
PubMed2001

Risk-benefit analysis of prophylactic pinning in slipped capital femoral epiphysis.

There is a broad and controversial discussion about the surgical procedure and the type of hardware for internal transfixation of the epiphysis and metaphysis in slipped capital femoral epiphysis (SCFE). Prophylactic pinning is even more controversial. One hundred and nine patients showing SCFE underwent a one-stage bilateral fixation of the epiphysis with three or four Kirschner wires (pins). From these 109 patients (69 male and 40 female), 94 had an unilateral slip and were operated prophylactically on the contralateral side. There were no complications such as avascular necrosis of the femoral head, chondrolysis, bone fracture, failure of metal implant, osteomyelitis or deep wound infection either at the time of surgery or at the minimum follow-up of 1 year with prophylactic pinning in SCFE. Therefore, we consider pinning allows for efficient stabilization, reliably preventing any progression of SCFE on the affected side and, furthermore, prevents the incidence of a secondary slip on the primarily nondisplaced contralateral side. The transfixation of epiphysis and metaphysis with Kirschner wires (pins) shows good subjective and objective long-term results compared with other surgical methods and implants. There is only a low morbidity rate with this method, because reoperations may only become necessary in the younger age group owing to normal growth of the femoral neck, compared with a high benefit from prophylactic surgical treatment of the nonaffected opposite side at the time of unilateral onset of the disease. The pins may no longer catch the epiphysis but further growth will allow for remodeling of the femoral head and for an optimal neck/shaft ratio. In case of further growth and relative shortening of the pins, refixation may become necessary. Therefore, we like to recommend the Kirschner-wire transfixation (pinning) of the epiphysis and metaphysis in patients with SCFE for primary treatment of SCFE as well as for prophylactic pinning of the contralateral side in one sitting.

Acute Disease↗
PubMed2000

Hemangioma of skeletal muscle.

Intramuscular hemangiomas are rare benign tumors, making up 0.8% of all hemangiomas. They are of interest to the surgeon because their location may present considerable therapeutic challenge since radiographic work-up of the soft- tissue mass by magnetic resonance imaging (MRI) may be suspicious for malignancy. The definitive diagnosis is made by histological study of the surgical and/or biopsy specimen. Patients with intramuscular hemangiomas may have soft-tissue complaints, such as pain and swelling, present for years. The gross and microscopic appearance of intramuscular hemangiomas is variable. Grossly, the capillary type is nonvascular and spongy in appearance, whereas the cavernous type is composed of large, thin-walled, dilated vessels lined by flattened endothelial cells. In general, wide excision is the treatment of choice to prevent local recurrence, but every patient with intramuscular hemangioma should be treated individually after evaluating the tumor location, accessibility, and depth of invasion, the patient's age, and cosmetic considerations. From October 1, 1989, to June 30, 1997, 11 patients underwent surgical treatment with the definitive histological diagnosis of intramuscular hemangioma. Pain upon activity but also at rest as well as swelling were the major symptoms. The average duration of symptoms was 13 months (range 1 month to 5 years). After a mean follow- up of 3 years and 4 months (range 12 months to 9 years), one of the patients has developed a recurrence; all remaining patients enjoy pain relief without any recurrence.

Adolescent↗
PubMed2000

[Torsion deformities in the lower extremities in patients with infantile cerebral palsy: pathogenesis and therapy].

Patients with spastic cerebral palsy often develop torsional deformities at the level of hip, shank or foot. The abnormal muscle activity such as spasticity or the increase of tone are considered as the major cause. The present study shows that the gait pattern is another cause which may lead to deformities. The study is based on gait analysis of 13 patients and 8 normal controls. The major and significant differences in gait kinematics were toe walking, toeing-in and internal rotation at the hip in the patients whereas the unaffected control group had a physiological heel-toe gait. The difference in torsional moments at the hip, knee and ankle were statistically significant. At the knee and the ankle a decrease in the internal rotation moment was found, whereas at the hip a paradoxical curve pattern with a more externally directed rotation moment was seen. These differences in torsional moments can explain the external rotation at the foot and/or shank as well as the increase in femoral anteversion, although they might be primarily caused by the deformity itself. Because a constantly acting force, however, changes the bony form and/or shape, the abnormal moments can be considered as a factor leading to deformities. A heel-toe gait seems to be mandatory for an efficient prophylaxis. Torsional deformities at the shank require a corrective osteotomy which is performed at the supramalleolar site and fixed by an unilateral, external fixator. Malrotations at the hip usually show two components: the functional part can be corrected by lengthening and weakening the tensor fasciae latae and the ventral parts of the glutei, using stretching exercises, botulinum toxin A or operative lengthening and releases. The increased femoral anteversion needs to be corrected by a femoral derotation osteotomy. Patients with cerebral palsy show a reduced control of their legs; therefore, balance internal torsion should not be corrected to neutral and overcorrection must be avoided. A remaining slight internal rotation after correction will help to spontaneously stabilize the leg if it gives way at initial contact, by "falling underneath the centre of gravity". If the leg is in neutral or external rotation, the patient needs to realign the centre of gravity over the dynamically unstable leg, showing a trunk-lean over the leg, the Duchenne limp.

Adolescent↗
PubMed2000

Potential role of direct adenoviral gene transfer in enhancing fracture repair.

Gene therapy has much to offer in the treatment of conditions in which it is necessary to increase the formation of bone. Nonunions, segmental defects, and aseptic loosening are examples of conditions where the local expression of genes that inhibit osteolysis and promote osteogenesis might be helpful. Studies in which one such possibility has been evaluated experimentally are described. These investigations used a surgically produced segmental defect in the femurs of New Zealand White rabbits as the model system. Adjacent muscle was fashioned around the defect to form a chamber into which adenoviral vectors were injected. High levels of transgene expression were found in the muscle surrounding the defect after injection of vectors carrying marker genes. Transgene expression also was seen in the cut ends of the bone and the scar tissue within the gap. No transgene expression was seen in the contralateral limb, spleen, or lung; transient, low levels of expression were found in the liver. Transgene expression declined with time, disappearing from all tissue but bone by Day 26; expression persisted in bone for at least 6 weeks. The control defects did not heal spontaneously. Injection of adenovirus carrying a human bone morphogenetic protein-2 complementary deoxyribonucleic acid led to healing of the segmental defect within 12 weeks, as judged by radiographic, histologic, and biomechanical criteria. Adenovirus carrying a human transforming growth factor-beta 1 complementary deoxyribonucleic acid showed signs of improved healing, but not to the extent seen with the bone morphogenetic protein-2 complementary deoxyribonucleic acid. This approach to therapy holds much promise as a novel means of promoting osteogenesis.

Adenoviridae↗
PubMed1999

[Recurrent club foot].

About 25% of operated clubfeet will develop a recurrency or show a marked residual deformity. As main factor the failure of concentric reduction at the time of initial surgery has to be considered. Residual forefoot adduction and supination are the most common persistent deformities. Based on the experience with 94 recurrent/residual clubfeet (patients < 10 years) the surgical treatment at different age-groups is presented. As a general rule soft tissue release is applicable as a repeated procedure until the age of about eight to ten years. For revision in patients between two and eight years we recommend a closing wedge osteotomy of the cuboid and a tibialis transfer additional to repeated release-procedures. In patients older than eight to ten years mid-tarsal osteotomies, correction according to llizarov with the external fixator or triple arthrodesis are to be considered as single or combined procedures.

Adolescent↗
PubMed1999

Chronic recurrent multifocal osteomyelitis in children: diagnostic value of histopathology and microbial testing.

Chronic recurrent, unifocal or multifocal osteomyelitis (CRMO), an inflammatory disorder of unknown origin, involves different osseous sites and may be associated with palmoplantar pustulosis. Bacterial cultures of affected tissue were reported negative in nearly all cases. Radiological and magnetic resonance imaging features of CRMO have been described, but differential diagnosis remains difficult, including rheumatic diseases, bacterial osteomyelitis, and malignancy. Although definite diagnosis relies on histopathologic confirmation by biopsy, histopathologic criteria have not been defined. Because CRMO may be treated with nonsteroidal antiinflammatory drugs, but not antibiotics, distinguishing CRMO from bacterial osteomyelitis is of major importance. Histopathologic analysis of 12 patients with CRMO indicated a wide variation of reparative changes of bone, but chronic inflammation could not be found at all sites in the same biopsy. The inflammatory infiltrate was mostly scattered, consisting mainly of lymphocytes, plasma cells, histiocytes, and also few neutrophil granulocytes. Immunohistochemistry showed a predominance of CD3(+), CD45RO(+) T-cells, which were mainly CD8(+). In addition, CD20(+) B cells and CD68(+) macrophages were abundant in each biopsy specimen. Mild lymphocytic and granulocytic infiltrates were also detected in three synovial biopsy specimens obtained from adjacent joints. All bacterial and fungal cultures from native biopsy tissues were negative. Amplification of partial-length 16S ribosomal DNA by polymerase chain reaction (PCR) using broad-range eubacterial primers was below the detection limit in all patients. Because histopathologic features alone may not provide conclusive evidence, CRMO should be included in the differential diagnosis of chronic inflammatory bone lesions in children, and the definite diagnosis should be made by the clinical picture, x-ray studies, bone scan, bacterial culture, and histopathologic analysis in a multidisciplinary approach.

Acquired Hyperostosis Syndrome↗
PubMed1999

Osteochondritis dissecans: a multicenter study of the European Pediatric Orthopedic Society.

To assess of the value of conservative and operative treatment of osteochondritis dissecans of the knee, a multicenter study was performed. In 12 European countries, 798 cases of osteochondritis of the knee have been collected from 44 hospitals. Results were based on 452 patients with 509 affected knees with minimum follow-up was 1 year (mean follow-up, 3 years and 11 months) and sufficient data for evaluation: 61% were male patients; 39% female patients; 318 affected knees were found in juvenile patients; 191 affected knees were in adult or premature patients. The localization was the medial femoral condyle on the lateral side in 51% (typical site) of patients. Various other sites were involved. Of the 509 affected knees, 154 were treated conservatively, 355 were treated surgically (many with multiple operations). For evaluation, the initial situation (at the time of the diagnosis) was favorable in 198 patients (no effusion, diameter of the lesion < 20 mm and no gross dissection on imaging) and unfavorable (one of the parameters did not meet these prerequisites) in 311 patients. The results were better in young patients than in adult patients. However, in the adolescent group, 22% of patients had abnormal knee at follow-up. The classical localization has a better prognosis than an unusual one. Patients with a favorable situation at diagnosis have significantly better results after conservative treatment than those who have undergone operation. When there are signs of dissection, the results are better after operative than after conservative treatment.

Adolescent↗
PubMed1998

Vertebral remodeling in eosinophilic granuloma of the spine. A long-term follow-up.

STUDY DESIGN: In this study, 14 conservatively treated patients were reviewed who had eosinophilic granuloma of the spine, which had been diagnosed on the basis of histologic study of the vertebral lesion or of specimens from other sites in patients with multiple involvement. The remodeling of the vertebral body was studied in an average follow-up of 5.6 years. OBJECTIVES: To analyze the remodeling process of the involved growing vertebral body in Langerhans Cell Histiocytosis after conservative treatment and to assess the sagittal and frontal profile of the spine at the end of growth. Fourteen patients, aged between 1.2 and 11.3 years, with spinal involvement of a Langerhans' cell histiocytosis were treated in the department of orthopedics between 1980 and 1990. All patients had immobilization of the affected region by a custom-made brace. Six patients with symptomatic lesions had radiotherapy and four patients with disseminated disease were treated with chemotherapy. Clinical and radiologic examinations were made at regular intervals to evaluate the development of the vertebrae during the remodeling process. SUMMARY OF BACKGROUND DATA: In the 14 patients, both sexes were affected equally. The disease was located in the cervical spine in two patients and in thoracic and lumbar vertebrae in seven patients each. Two patients had two vertebral lesions. METHODS: The radiologic evolution of the 16 vertebral lesions was evaluated using follow-up standardized lateral radiographs. The reconstitution of the vertebral height in the presence of vertebra plana was calculated by measuring the ventral distance between the superior and inferior margins of the vertebral body in relation to the adjacent uninvolved vertebra. RESULTS: The measurements showed a growth rate of 1.5-6 (average, 3) in vertebrae with vertebra plana and a growth rate of 1.1-2.7 (average, 1.4) in the unaffected vertebra. The reconstitution of the vertebral height was between 18.2% and 63.8% of the adjacent vertebrae before and between 72.2% and 97% after skeletal maturity. CONCLUSIONS: The results demonstrate that conservative orthopedic treatment with immobilization in a brace is sufficient to allow for optimal vertebral remodeling. Partial to nearly complete reconstitution of vertebral height was seen in all cases. Thus, operative treatment with curettage of the lesion and bone grafting including multisegmental fusion with instrumentation is not necessary. In instances with neurologic impairment, rarely seen in adults, surgical decompression and short fusion of the spine is necessary. Nevertheless, complete staging and biopsy are mandatory for an accurate diagnosis.

Bone Remodeling↗
PubMed1998

Transposition of a vascularised distal femoral bone graft after wide resection of a diaphyseal Ewing's sarcoma--a salvage procedure.

We report a case of a 26-year-old woman with a surgical stage IIb lesion of Ewing's sarcoma of the left femur diaphysis. After intracompartmental wide resection a custom-made diaphyseal spacer was inserted for optional secondary biological reconstruction. Treatment-associated complications such as loosening of the implant and a septic process made a limb-preserving procedure impossible, and therefore a salvage procedure with transposition of the vascularised distal femur as a graft for lengthening of the short proximal femur was necessary. This unfortunate course is an example of limb-salvage surgery that not infrequently leads to reoperations or ultimately an amputation. Therefore individual surgical procedures have to be considered to provide the best limb function.

Adult↗
PubMed1998

Chronic recurrent osteomyelitis with clavicular involvement in children: diagnostic value of different imaging techniques and therapy with non-steroidal anti-inflammatory drugs.

UNLABELLED: Chronic recurrent, uni- or multifocal osteomyelitis (CRMO), an inflammatory disorder of unknown origin, involves mk:/night/arul/4310946m.3dultiple osseous sites and may affect the clavicle. We report on 6 children with clavicular involvement out of 11 children suffering from CRMO. The major clinical symptoms were local swelling and pain. Five children had hyperostosis of the clavicle and synovitis of adjacent joints. Histology showed chronic osteomyelitis with a predominance of lymphocytes in the inflammatory infiltrates. Cultures of biopsy tissue specimens were sterile. The patients were followed for at least 3.5 years. Three patients had up to six relapses. The most effective diagnostic tools to define CRMO were standard X-ray and bone scan in combination with biopsy and cultures. In our patients CT and MRI were misleading as they suggested the presence of malignancy. However, the sensitivity of MRI to detect involvement of bone, adjacent joints and soft tissues were better in comparison to X-ray or bone scan. Non-steroidal anti-inflammatory drugs were effective in reducing pain, swelling and limitation of motion. Reconstructive surgery was not indicated in any case. The long-term outcome of growth and function of affected bones was excellent. CONCLUSION: Diagnosis of chronic osteomyelitis of the clavicle should be made by history and physical examination and be confirmed by standard X-ray, bone scan and open biopsy. In contrast MRI and CT can provide data on the involvement of adjacent joints, soft tissue and muscles especially in the early process of disease, but do not add information relevant to the patient's management. Treatment with non-steroidal anti-inflammatory drugs is rapidly beneficial in most patients.

Adolescent↗
PubMed1997

[Lymphoplasmacellular osteomyelitis].

Chronic lymphoplasmacellular osteomyelitis may occur in children, adolescents and adults, but has not been found in newborns or babies either in our series or in the literature. Symptoms suggesting an acute disease like fever are uncommon, but a primary chronic course with symptomatic and asymptomatic periods is typical. Pain and swelling are the main symptoms; painless masses are rare. In children and adolescents the clavicle and metaphyseal regions of long bones are typical sites of chronic abacterial osteomyelitis. In adults the clavicles or the first two ribs are mainly affected with synovitis of the adjacent joints, but the long bones are rarely involved. Laboratory findings are non-specific but important for the differential diagnosis. The sedimentation rate and c-reactive protein might be elevated. The X-ray examination shows osteolytic, sclerotic or mixed bony changes and, in case of a diaphyseal involvement, onionskinlike periosteal bone formation may be present, suggesting a malignant process. In late stages sclerotic bone formations may be seen as a rest. Uni- or multifocal lesions can be detected by bonescan, as can asymptomatic lesions. Magnetic resonance imaging shows gross signal intensity differences both in the bone and perifocal soft tissue and involvement of the synovium with gadolinium DPTA enhancement in T1-weighted images. In early stages of the disease granulocytes, microabscesses and new bone formations might suggest bacterial osteomyelitis that cannot be differentiated by histology. In intermediate phases lymphocytic and plasma-cellular infiltrates are found, whereas in late phases sclerotic bone formations and fibrosis of the bone marrow are seen histologically. In chronic lymphoplasmacellular osteomyelitis, all clinical, radiological and histological findings, as well as negative bacteriological cultures, are mandatory and will allow a definitive diagnosis to be made. The disease may be uni- or multifocal, and new bone lesions may occur over time, as well as skin manifestations, which can be found years before or after bone involvement. The association with dermatological diseases and/or synovitis led to the acronym SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, osteomyelitis). For the treatment nonsteroidal anti-inflammatory drugs are effective for pain relief, reduction of swelling and dysfunction. Antibiotics have been used in several series and are not effective. Major surgery is not recommended even for recurrences, and the prognosis for growth and function is excellent in the long term despite recurrences over several years.

Adolescent↗
PubMed1996

Malignant hyperthermia (MH) diagnostics: a comparison between the halothane-caffeine- and the ryanodine-contracture-test results in MH susceptible, normal and control muscle.

Recent studies demonstrated different contracture responses in muscle from malignant hyperthermia susceptible (MHS) compared to normal (MHN) individuals following exposure to the plant alkaloid ryanodine in-vitro. To confirm if ryanodine has a specific action in MHS muscle, the effect of a single concentration was investigated in skeletal muscle from MHS, MHN and control subjects using a new evaluation technique. In-vitro contracture test (IVCT) and MH diagnosis were performed according to the European Protocol in 86 patients sent to us for MH diagnostic testing and in 24 controls. Viable fresh muscle bundles were exposed to a single bolus of ryanodine 1.0 microM. Contracture onset time (OTp: defined as the time (min) from administration of ryanodine to the start of a contracture as measured by a contracture exceeding predrug baseline height), and the time to an increase of the baseline height to 10 mN above the predrug level (10Tp) were recorded. 29 patients were identified by IVCT to be MHS, 50 MHN, 7 MHE (equivocal) and 24 controls MHN. The indices from the ryanodine test separated all MHS (OTp: < 16 min; 10Tp < 27.4 min) from MHN (> 18 and > 27.7 min) and control subjects (> 17.4 and > 29 min). Values for MHE (equivocal) individuals ranged from 17.1 to 27.8 min for the OTp and from 32 to 49.2 min for the 10Tp. 5 patients with fulminant MH crises were included in the MHS group and showed the 95% confidence intervals (CI) of the median value < or = 8.05 min (OTp) and < or = 13.35 min (10TP) for MHS. In contrast, CI of the median value for the control group were found to be > or = 25.2 min (OTp) and 43.15 min (10Tp) for normal muscle. Thus the ryanodine test protocol showed markedly different contractures in MHS and MHN or control muscle. These results suggest that MHS muscle has a higher sensitivity to ryanodine. However, the protocol should be investigated for reproducibility and validation of thresholds by other laboratories. Ryanodine can help to improve MH diagnostic tests.

Adolescent↗
PubMed1995

Distribution of neurofilament-positive nerve fibres and sensory endings in the human anterior cruciate ligament.

The present immunocytochemical study describes the distribution of neurofilament-containing nerve fibres and corpuscular-like endings in the human anterior cruciate ligament. The entire anterior cruciate ligament of a non-injured knee joint from a child was cut into serial 15-microns-thick frozen sections, which were processed for immunofluorescence staining with a monoclonal antibody against the 68-kDa neurofilament subunit. Numerous neurofilament-positive fibres were found in bundles. These bundles were mostly located near blood vessels in the subsynovial layer and in interfascicular gaps. Only a few single nerve fibres were found independent of blood vessels in interfascicular gaps and between collagen bundles. Neurofilament-containing nerve fibres were preferentially located near the bony attachments of the anterior cruciate ligament. Two types of corpuscular-like endings were found, i.e. "spiral-like" (type I) and "spray-like" (type II) endings. Similarly to nerve fibres, both types of corpuscular-like endings were found mainly near the tibial and femoral attachment sites (15 of 17), whereas only two were found in the middle third of the ligament. Most likely, the type I and type II corpuscular-like endings serve a mechanoreceptive function involved in the sensory control of normal movements and in stress protection.

Anterior Cruciate Ligament↗
PubMed1995

[Chondroma, chondroblastoma and chondromyxoid fibroma].

Chondromas are benign tumors characterized by the formation of mature cartilage. Typically, they involve the short bones of the hands and feet. The lesions may be either solitary or multiple as part of enchondromatosis affecting several bones. Cases of multiple enchondromatosis with predominantly unilateral distribution are generally referred to as "Ollier's disease" or when accompanied by multiple hemangiomas as "Maffucci's syndrome". In cases with multiple chondromas there is considerable risk of malignant transformation (approximately 50%). Treatment of single lesions (curettage and bone grafting) is usually uneventful, but any therapeutic approach to Ollier's disease or Maffucci's syndrome should be tailored to the individual distribution of lesions in the most severely deformed extremities. Chondroblastomas are uncommon benign tumors that are almost invariably situated in the epiphyses of long bones adjacent to the epiphyseal cartilage plate. Histologically, they are characterized by round or polygonal chondroblasts with focal accumulation of osteoclast-like giant cells. Intercellular substance is scanty, and calcification occurs typically at focal areas. Lung metastases are reported in rare single cases with high survival rates after local resection, indicating low-grade malignancy. Only a few recurrences have been reported following curettage and bone grafting. Avascular necrosis or chondrolysis with subsequent secondary osteoarthrosis may occur after surgical treatment of chondroblastoma of the upper femur epiphysis. These severe indirect sequelae should be considered both when planning surgery and during follow-up. Chondromyxoid fibromas are rare benign tumors that are mostly diagnosed in the second and third decade; they are mainly found in the proximal tibial metaphysis. Histologically, there are areas of chondroid, myxoid, and fibrotic tissues, of which the myxoid component is characteristic for chondromyxoid fibromas.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Dorsal hemivertebrae in children's lumbar spines.

STUDY DESIGN: Only small numbers patients with dorsal hemivertebrae have been reported. The natural course of this disease remains unpredictable, especially regarding the development of neurologic impairment. Two children with congenital dorsal hemivertebra with progressive kyphosis of the lumbar spine are presented. Onset and method of treatment are discussed. OBJECTIVES: Two boys with kyphosis due to dorsal hemivertebrae of the lumbar spine were followed with clinical examination, anteroposterior roentgenograms, and magnetic resonance imaging. One patient was in follow-up for more than 4 years postoperatively. The other patient, who has not undergone surgery, has been in follow-up for more than 2 years, undergoing reassessment every 4 to 6 months. SUMMARY OF BACKGROUND DATA: Spastic paralysis developed in one patient with dorsal hemivertebra and spina bifida. The other patient with dorsal hemivertebra and sacral agenesis had no neurologic deficit. METHODS: A dorsal approach with resection of the dorsal hemivertebra and short dorsal fusion with internal fixation was done in one patient. The other patient underwent clinical and radiologic follow-up. Method and onset of surgical treatment were compared with other studies. RESULTS: Progressive spasticity was seen in our first patient. This could be reversed by resection of the hemivertebra and monosegmental fusion. Alignment of the spine and normalization of the width of spinal canal were achieved. The second patient has not had a neurologic problem. Surgical treatment will be performed when indicated. CONCLUSIONS: A posterior approach is recommended for a dorsal hemivertebra. Decompression of the spinal canal can be achieved by resection of the dorsal hemivertebra and short dorsal fusion with internal fixation. Surgery should be done early to avoid late neurologic impairment.

Age of Onset↗
PubMed1992

Sensory innervation of the anterior cruciate ligament. An electrophysiological study of the response properties of single identified mechanoreceptors in the cat.

In anesthetized cats, electrophysiological recordings were made from twenty-six single thick myelinated afferent fibers of the posterior articular nerve of the knee joint that had sensory endings in the anterior cruciate ligament. Most afferent fibers arising from the anterior cruciate ligament were activated by application of local pressure to discrete sites of the ligament, near the attachment to the femur. Afferent fibers from the anterior cruciate ligament did not fire when the knee was in the resting position at 30 degrees of flexion, but they were activated when the knee joint was extended and flexed and externally or internally rotated. Whereas responses were induced by movements in the working range of motion of the knee, activity was markedly increased when the joint was hyperextended and externally or internally rotated. These findings suggest that mechanoreceptors with myelinated axons provide information about tension of the anterior cruciate ligament.

Animals↗
PubMed1991

[Diagnosis of malignant hyperthermia. The platelet test versus the in vitro contracture test].

An eight-year-old boy was scheduled for an orthopaedic operation with a clinically abortive reaction of malignant hyperthermia and a positive platelet test result. Since there has been no validation for this platelet test, we performed a muscle biopsy and the caffeine- halothane-contracture test (CHCT). The young patient was found to be negative (MHN) in CHCT. Furthermore, the valence and the validity of the used platelet test are discussed for diagnostic purposes. With regard to resulting consequences, first of all in respect of possibly false negative results, we suggest to investigate all patients classified by this platelet test with the accepted and established CHCT.

Blood Platelets↗