[Measurement of the AT and the CCD angle of macerated cadaver femora: a comparative study between CT and MRI measurements]. / Die Bestimmung des AT- und CCD-Winkels am mazerierten Leichenfemur--Eine Vergleichsstudie zwischen CT- und MRT-Messung und Direktmessung am Präparat.

PURPOSE: To compare measurements of the real AT (femoral antetorsion) and CCD (caput-collum-diaphysis) angle by computed tomography (CT) and magnetic resonance imaging (MRI) of hip specimen using direct measurements as reference standard, and to show that measurement by MRI can replace CT measurements and may help avoiding X-ray exposition. MATERIALS AND METHODS: CT and MRI measurements were obtained on 25 in water-arrested macerated human femora. Postprocessing was done by 4 independent readers on a workstation using a dedicated 3D-software. Direct measurements of the real AT and the CCD angle were used as reference standard. The analysis included Student's t test for paired values, interobserver variability using intra-class correlation coefficients (ICC), maximum and middle divergence of the angles, and Bland-Altman plots. RESULTS: For determining AT and the CCD angle with CT and MRI, good correlation was found between the 4 readers and with measurements using the reference standard. ICCs were 0.97 and 0.90 for measuring AT and CCD angle with CT, and 0.95 and 0.71 for measurements with MRI, respectively. Mean divergence between CT measurements and those of the reference standard was 0.8 degrees for AT and 0.7 degrees for the CCD-angle. Mean divergence between MRI measurements and those of the reference standard was 0.3 degrees for AT and -0.4 degrees for the CCD-angle. Mean divergences between CT and MRI measurements of AT and CCD-angle were 0.5 degrees. Neither systematic errors nor dependences on the qualitative size of the reference data were evident in the divergences of measurements. CONCLUSION: Measurements of the real AT and CCD angle by CT and MR imaging revealed a good correlation with direct measurements of the femoral specimen and consequently can be recommended for clinical use. MRI measurements can replace CT measurements, avoiding X-ray exposure especially in young patients undergoing preoperative evaluation for hip dysplasia.

Characterization of aquatic humic substances and their metal complexes by immobilized metal-chelate affinity chromatography on iron(III)-loaded ion exchangers.

The analytical fractionation of aquatic humic substances (HS) by means of immobilized metal-chelate affinity chromatography (IMAC) on metal-loaded chelating ion exchangers is described. The cellulose HYPHAN, loaded with different trivalent ions, and the chelate exchanger Chelex 100, loaded to 90% of its capacity with Fe(III), were used. The cellulose HYPHAN, loaded with 2% Fe(III), resulted in HS distribution coefficients Kd of up to 10(3.7) mL/g at pH 4.0 continuously decreasing down to 10(1.5) at pH 12, which were appropriate for HS fractionation by a pH-depending chromatographic procedure. Similar distribution coefficients Kd were obtained for HS sorption onto Fe(III)-loaded Chelex 100. On the basis of Fe-loaded HYPHAN both, a low-pressure and high-pressure IMAC technique, were developed for the fractionation of dissolved HS applying a buffer-based pH gradient for their gradual elution between pH 4.0 and 12.0. By coupling the Chelex 100 column under high-pressure conditions with an inductively coupled plasma mass spectrometer an on-line characterization of HS metal species could be achieved. Using these fractionation procedures a number of reference HS were characterized. Accordingly, the HA (humic acids) and FA (fulvic acids) studied could be discriminated into up to 6 fractions by applying cellulose HYPHAN, significantly differing in their Cu(II) complexation capacity but hardly in their substructures assessed by conventional FTIR. In the case of using Chelex 100 exchanger resin two major UV active HS fractions were obtained, which significantly differ in their complexation properties for Cu(II) and Pb(II), respectively.

Comparison of the sympathetic skin response and continuous wave Doppler sonography of the radial artery.

The value of neurophysiological tests of the autonomic nerve system is limited. One of the clinically most commonly applied test is the skin sudomotor response, frequently referred to as 'sympathetic skin response' (SSR). However, the SSR is a more qualitative than quantitative evaluation technique. Continuous wave (cw) Doppler sonography of the radial artery may be an alternative quantitative approach. We studied 41 age matched volunteers (23 female, 18 male; 16-82 years (mean age 53 years)). The stimulus was a loud and unexpected acoustic signal, alternatively a cough. SSR evaluation included the latency of onset, the duration and the amplitude of the response. Doppler evaluation also included flow velocity and resistance index (RI) changes with adequate stimulation. SSRs were observed in 36 volunteers (88%), Doppler responses in 35 (85%). The latency between stimulus and response onset was 1.35 s with SSR and 1.52 s with ultrasound (n.s.). The mean SSR amplitude was 1.3 mV, systolic velocities decreased by 20% and diastolic velocities by 124% (flow reversal). RI increased from 0.85 to 1.25 with no correlation between SSR amplitude and flow velocity changes. SSR and cw Doppler are complementary methods. Doppler sonography offers an additional approach of autonomic nerve evaluation.

Significance of radiographic angle measurements in evaluation of congenital clubfoot.

Numerous formal, positional and angular foot skeleton deviations have been described in radiographic evaluation of congenital clubfoot. To clear up the correlation between clinical and radiological findings, a retrospective study involving 62 cases of congenital clubfoot in 38 patients was carried out, including follow-up observation for 7 years after soft-tissue surgery. Only clubfeet with grade II Harrold and Walker classifications according to the initial findings were included. Clinical follow-up examinations followed the Functional Rating System (FRS) of Laaveg and Ponseti. The postoperative talocalcaneal (TC) angle, measured on a lateral image, averaged 23 degrees as opposed to 32 degrees in healthy feet, i.e. much smaller, although this very significant angle dimension showed only minimum differences between the evaluation groups "very good" to "poor". The TC angle anteroposterior (AP), talonavicular angle (AP and lateral) as well as the calcaneometatarsal V angle revealed considerable deviations, although a correlation of clinical severity grading with the measured angular dimensions was not possible due to measurement imprecision and the range of values occurring within the different severity groups.

Dose-related effects of shock waves on rabbit tendo Achillis. A sonographic and histological study.

We aimed to determine whether extracorporeal shock waves of varying intensity would damage the intact tendo Achillis and paratenon in a rabbit model. We used 42 female New Zealand white rabbits randomly divided into four groups as follows: group a received 1000 shock-wave impulses of an energy flux density of 0.08 mJ/mm2, group b 1000 impulses of 0.28 mJ/mm2, group c 1000 impulses of 0.60 mJ/mm2, and group d was a control group. Sonographic and histological evaluation showed no changes in group a, and transient swelling of the tendon with a minor inflammatory reaction in group b. Group c had formation of paratendinous fluid with a significant increase in the anteroposterior diameter of the tendon. In this group there were marked histological changes with increased eosin staining, fibrinoid necrosis, fibrosis in the paratenon and infiltration of inflammatory cells. We conclude that there are dose-dependent changes in the tendon and paratenon after extracorporeal shock-wave therapy and that energy flux densities of over 0.28 mJ/mm should not be used clinically in the treatment of tendon disorders.

Changes of sonographic, magnetic resonance tomographic, electromyographic, and histopathologic findings within a 2-month period of examinations after experimental muscle denervation.

This study compares sonographical, histopathological, magnetic resonance imaging (MRI), and electromyographical (EMG) findings following acute muscle denervation. We performed an experimental denervation of the supraspinatus and infraspinatus muscles on 35 New Zealand white rabbits by segment resection of the suprascapular nerve. The sonographical appearance of the supraspinatus muscle was followed and documented at short time intervals within a 2-month follow-up period. The sonographical, histopathological, and MRI changes due to denervation suggest a regular pattern. Apart from the reduction of the muscle diameter, there were considerable sonographical signs of denervation with an increase of echointensity and inhomogenicity of echotexture that appeared on day 14 after injury, and progressed continuously with time. MRI revealed a remarkable increase in signal intensity 3 weeks after denervation and reproducible T2 times. Pathological spontaneous activity on EMG could also be detected from day 14 after injury. Conventional histopathological staining methods (H&E, NADH, ATPase, basic and acid phosphatase) confirmed denervation and absence of reinnervation. The first nonspecific histopathological changes were seen 11 days after denervation in the form of moderately atrophic fibers. Typical histopathological signs of denervation appeared 3 weeks after nerve dissection. In summary, EMG, ultrasound, MRI, and histopathology each showed first abnormalities after about 2 weeks. In addition to EMG, sonography and MRI can document the course of muscle atrophy and mesenchymal abnormalities in neurogenic muscle lesions.

Preoperative estimation of screw fixation strength in vertebral bodies.

STUDY DESIGN: Bone mineral density and bone cross-sectional area of human cadaveric vertebral bodies were investigated radiologically and histologically, respectively. After ventral instrumentation with ventral derotation spondylodesis screws, axial pullout force was measured and compared with radiologic and histologic data. OBJECTIVES: To elucidate how well ventral derotation spondylodesis screw fixation strength can be estimated before surgery by specified applications of dual-energy x-ray absorptiometry, quantitative computed tomography, T2*-relaxation time in magnetic resonance imaging, and histomorphometry. SUMMARY OF BACKGROUND DATA: It is postulated that bone quality plays a crucial role in initial strength of the instrumented spine. Bone quality is even more important in anterior fixation because of the prevalence of spongy bone in the vertebral body. METHODS: Bone mineral density of human cadaveric lumbar-vertebral bodies was assessed by dual-energy x-ray absorptiometry and quantitative computed tomography (cancellous and cortical bone separately). Cancellous bone was also characterized by T2*-relaxation time, measured by magnetic resonance imaging and histomorphometric study. Vertebral bodies were instrumented ventrally with VDS screws, and screw axial pullout force was measured and correlated with each of the nonmechanical measures. Patients with manifest osteoporosis, osteomalacia and tumors were excluded. For statistical analysis, the Mann-Whitney rank sum test was used with a significance value of P < 0.05. RESULTS: The highest correlation with pullout force was for density of cancellous bone determined by quantitative computed tomography (r = 0.72; P < 0.001), immediately followed that determined by dual-energy x-ray absorptiometry (r = 0.70; P < 0.001). Results of measurement of T2*-relaxation time and those of histomorphometric study correlated moderately (r = 0.55; r = 0.50), whereas cortical bone density determined by quantitative computed tomography showed negligible correlation (r = 0.2). CONCLUSIONS: The absorptiometric techniques, quantitative computed tomographic scan of cancellous bone and dual-energy x-ray absorptiometric study, provide more accurate readings for preoperative estimation of initial VDS screw fixation strength than do the other methods studied.

[Ultrasound image of the lumbar spine and the lumbosacral transition. Ultrasound anatomy and possibilities for ultrasonically-controlled facet joint infiltration]. / Die Sonographie der Lendenwirbelsäule und des lumbosakralen Uberganges. Sonoanatomie und Möglichkeiten der sonographisch gesteuerten Facettengelenksinfiltration.

QUESTION: Is sonography helpful in facet joint infiltration of the lumbar spine? METHOD: The sonoanatomy of the lumbar spine and the of lumbosacral junction was examined and described in a skeleton and in 10 volunteers. One representative cross section and 3 longitudinal sections were defined. According to these results (no neurological symptoms) the possibilities of ultrasound guided infiltration of the facet joints was examined in 78 patients (36 female, 42 male, average age 55 y., 38-78 y.) with chronic low back pain and increase of pain by hyperextension. 5 ml Carbostesin partially in combination with steroids were applied to each joint. In all cases the tip of the syringe could be placed on the joint. RESULTS: There were no complications, especially no infection or neurological symptoms. Application of local anaesthetics into the spinal canal could be excluded in all cases. The sonoanatomy of the lumbar spine and of the lumbosacral junction can be reproduced. Sonography allows an accurate infiltration of the facet joints of the lumbar spine. Applications into the spinal canal can be avoided. CONCLUSIONS: This method is a secure and economic (extra time 2-4 min.) alternative to clinically guided infiltration. Flouroscopy guided infiltration is needed only in anatomical variations or if strictly intraarticular application is necessary.

[Traumatically-induced compartment syndrome of the tibia. Ultrasound diagnosis for qualitative assessment of late sequelae for musculature after dermatofasciotomy]. / Das traumatisch bedingte Kompartmentsyndrom des Unterschenkels. Ultraschalldiagnostik zur qualitativen Beurteilung von Spätfolgen der Muskulatur nach Dermatofasziotomie.

To determine the significance of sonography in evaluating long-term damage of muscle surgically treated for compartment syndrome 27 patients of the Department for Trauma Surgery, University Clinic Essen, Germany, were examined on their anterior lower limb after an average of 98 (43 to 154) months after trauma. They had had a fasciotomy for imminent (n = 15) or manifest (n = 12) compartment syndrome. Comparing the healthy side a qualitative grading (0 to 3) of the changes could be introduced reflecting the extent of the increase in echogenicity and the loss of the typical muscle texture. Gray scale histograms confirmed the qualitative grading. Patients with manifest compartment syndrome showed severe changes (grade 2 and 3). In imminent compartment syndrome 2 patients with grade 2 and 13 patients with grade 0 or 1 were found. The sonographical changes can be explained by the known pathomorphological changes after compartment syndrome (denervation, scarification). Sonography is useful in the evaluation of soft tissue after compartment syndrome. The results underline the demands of early fasciotomy in imminent compartment syndrome for prevention of damage of muscle and nerve.

[Extracorporeal shock-wave therapy. Experimental basis, clinical application]. / Extrakorporale Stosswellentherapie. Experimentelle Grundlagen, klinischer Einsatz.

The purpose of our studies was to investigate experimentally the dose-dependent effects of extracorporeal shock waves on tendon and bone and to unveil therapeutic possibilities in tendinopathies and pseudarthroses. In animal experiments, both positive and negative influences were exerted by shock waves, depending on the initial situation and on the power of the applied shock waves. In prospective clinical trials positive effects were found in the treatment of persistent tennis elbow, plantar fasciitis, calcifying tendinitis, and pseudarthrosis. Our data show that extracorporeal shock waves may provide analgesic, resorptive and osteo-inductive reactions with nearly no side effects. However, the high cost of apparatus and staff prevents a routine application. Extracorporeal shock waves thus remain a last alternative before the indication is made for an operative procedure.

Sonography and MRI of experimental muscle injuries.

After sonographical examination with a 7.5-MHz linear array scanner, we created an experimental muscle injury of known site and location on 28 New Zealand white rabbits by stabbing them with a scalpel in the supraspinatus muscle. The changes in the healing process were followed and documented by sonography and magnetic resonance imaging (MRI) before and 2, 5, 11, 14, 36 and 64 days after injury. The changes in sonography and MRI followed a regular course. Ultrasound revealed an echo-poor area after injury with ever increasing echogenicity from the 14th day. Strong reflexes were found after 2 months. MRI showed few changes, only a slight increase of signal intensity, but a characteristic curve of calculated T2-times (a program of the MRI software). The interpretation of the sonographical picture in histopathological terms remained limited. The development of a hematoma and of fibrous scars can be followed up by sonography, but it is not possible to determine the point of time after injury very accurately. Nevertheless, sonography is a method of great value in the diagnosis of muscle injuries and, given certain limits, in the follow-up of the healing process, too. The significance of MRI can be increased by calculations with the implemented software, as in our study calculated T2-times produced a characteristic curve reflecting the shift of fluids after muscle injury.

[Extracorporeal shockwave treatment of delayed bone healing. A critical assessment]. / Extrakorporale Stosswellenapplikation bei gestörter Knochenheilung. Eine kritische Bestandsaufnahme.

Since the late 1980s, experiments have been performed to influence physiologic and disturbed healing of bone. However, the mainly negative results of animal studies, cannot be applied to the human nonunion situation as long as there is no adequate animal pseudarthrosis model. Prospective clinical studies in various centres have resulted in success rates of more than 50%, although the majority of patients had been treated repeatedly and ineffectively with the gold standard of re-osteosynthesis and grafting. Since the mechanisms are not yet understood, only such desperate conditions are an indication for the application of high-energy extracorporal shock waves.

[Long-term results of triple arthrodesis in neurogenic foot deformities]. / Langzeitergebnisse nach Triple Arthrodese bei neurogenen Fussdeformitäten.

The number of good results after triple arthrodesis due to neuromuscular foot disorders in literature varies between 24% and 94%. 46 patients with 64 triple arthrodesis due to neuromuscular foot disorders were reexamined 18 years (15 to 25 years) after the operation. In 36 cases arthrodesis was performed by k-wire and pin fixation and in 28 cases by k-wire and screw-fixation. For preoperative and follow-up grading the McGuire score was used which increased on the average due to the operation from 58 to 89 points. Good and excellent results were found in 91% of the patients. Triple arthrodesis in patients with neuromuscular foot disorders is recommended. It leads to functional good results with a small amount of complications.

[Intraoperative ultrasound in lumbar intervertebral disk displacement]. / Intraoperative Sonographie bei lumbalen Bandscheibenvorfällen.

UNLABELLED: Intraoperative ultrasound of the spine has been used in neurosurgery (tumours) and traumatology (reposition of fractured vertebral bodies fragments). AIM: To describe initial experiences with this method and to document the opportunities and problems. METHOD: 24 nucleotomies were documented and evaluated. Sonography was performed using a 7.5 MHz sector probe and a typical surgical approach. RESULTS: In 21 of 24 cases, imaging of intraspinal structures was possible. The complete extraction of the herniated disk could be documented. In 3 cases the examination failed because the probe was too large to be pushed down between the spinous processes and the wound retractor to the operative site. CONCLUSIONS: Intraoperative sonography can be used easily as a routine method for exploration of the spinal canal. Technical innovations in the probes would make the method even more feasible.

[Ultrasound follow-up after experimental muscle denervation]. / Sonographische Verlaufskontrolle nach experimenteller Muskeldenervierung.

AIM: To describe sonographical results following acute, experimental muscle denervation. METHOD: Denervation of the supraspinatus and infraspinatus muscles was performed in 28 New Zealand white rabbits by segmental resection of the suprascapular nerve. The changes in the sonographic image of the muscles were follow up and documented at short intervals over 2 months. RESULTS: The sonographically detectable changes following denervation follow a definite pattern. In addition to the reduction in muscle diameter, sonographical signs of denervation include an increase of echodensity and an inhomogeneity of echotexture that appeared on day 14 after injury and became more prominent at larger intervals. CONCLUSION: Sonography may play a supportive role in the diagnosis and follow-up of neurogenic muscle atrophy.

[Ultrasound anatomy of the spinal canal of the lumbar spine. Results ofan experimental study and report of initial clinical applications of intraoperative ultrasound in nucleotomies]. / Die Sonoanatomie des Spinalkanales der LWS. Ergebnisse einer experimentellen Studie und ein Bericht über erste klinische Anwendungen der intraoperativen Sonographie bei Nukleotomien.

UNLABELLED: Results of an Experimental Study and Report of Intraoperative Application: AIM: Intraoperative sonography has been used in neurosurgery (especially in tumors) and in traumatology (assess reduction of dorsal vertebral body fragments). This study was performed to determine the value of sonography in detecting vertebral disc tissue. RESULTS: We examined 6 specimens of the Lumbar spine using the extended flavectomy approach. We found that sono-anatomy was reproducible and that the assessable area was large enough to make sonography useful for detection of sequesters. Dislocated vertebral disc tissue could be differentiated clearly from original disc tissue and from other intraspinal structures. In 6 of 8 cases of intraoperative sonography in nucleotomies we were able to evaluate intraspinal and intraforaminal structures. The complete removal of the detected prolapses could be documented. In 2 cases the examination failed because the probe had a too large diameter and could not be pushed down between the spinous processus and the wound distractor to the extended flavectomy. CONCLUSIONS: Sonography allows one to document complete resection of disc herniations. Limitations of the method are due to technical problems.

[Progression of arthrosis after alloplasty--what factors play a role?]. / Arthroseprogression nach alloplastischer Kreuzbandoperation--Welche Faktoren spielen eine Rolle?

From 87 patients who underwent anterior cruciate ligament (ACL) surgery with an alloplastic ligament (Trevira hochfest) the radiographs of 77 patients were examined by 2 physicians, who were not involved in the operation. They evaluated the increase of degenerative osteoarthritis according to the classification by Holz [12] finding a significant increase of degenerative osteoarthritis after surgery with a mean follow-up of 41.2 months. The ligament reconstruction was performed in 50 fresh ACL tears by reinsertion plus synthetic ligament protection and in 27 chronic instabilities with several failed previous operations by using the alloplastic ligament as an ACL prosthesis by means of a salvage procedure. Both investigators found a significant increase of degenerative osteoarthritis in both groups, but the chronically instable knees had a higher initial value. Patients with concomitant meniscus and/or posterior cruciate ligament (PCL) ruptures showed the highest increase of osteoarthritic changes; isolated ACL tears were found with very low degeneration. Considering the special profile of our collective, the factors that were found to as a risk of osteoarthritis and the comparison with the literature we could not find any indication for a relevantly increased risk of osteoarthritic progression using the Trevira hochfest ligament.

Analgesic effect of extracorporeal shock-wave therapy on chronic tennis elbow.

We report a controlled, prospective study to investigate the effect of treatment by low-energy extracorporeal shock waves on pain in tennis elbow. We assigned at random 100 patients who had had symptoms for more than 12 months to two groups to receive low-energy shock-wave therapy. Group I received a total of 3000 impulses of 0.08 mJ/mm2 and group II, the control group, 30 impulses. The patients were reviewed after 3, 6 and 24 weeks. There was significant alleviation of pain and improvement of function after treatment in group I in which there was a good or excellent outcome in 48% and an acceptable result in 42% at the final review, compared with 6% and 24%, respectively, in group II.

[Magnetic resonance tomography and histopathologic findings after muscle denervation. A comparative animal experiment study during a two month follow-up]. / Kernspintomographische und histopathologische Befunde nach Muskeldenervierungen. Eine vergleichende tierexperimentelle Studie während einer zweimonatigen Verlaufsuntersuchung.

Recently, MRI was described as a method in the diagnosis of changes of muscle after acute neurogenic muscle atrophy. This study was performed to compare MRI results with myopathological findings, to document the appearance of the MRI changes and to check the sensitivity of this method. We performed a segment resection of the suprascapular nerve resulting in a denervation of the supraspinatus and infraspinatus muscles on 18 Newzeeland white rabbits. MRI changes were followed and documented for two months in short periods of time. The results were compared with histological findings. In myopathology and MRI we found systematical changes: Apart from the reduction of the muscle diameter visual assessment revealed increased signal intensities on the 21st and 35th examination day after denervation. On the 2nd, 5th, 11th and 64th examination day signal intensities were normal. The changes were represented by calculated T2 times, too.

[Possibilities and limits of interpretation of muscle sonograms. An experimental study of standardized muscle injuries]. / Möglichkeiten und Grenzen der Interpretation von Muskelsonogrammen. Eine experimentelle Studie standardisierter Muskelverletzungen.

After sonographical examination we performed surgically an experimental muscle injury of known size and location on 28 New Zealand white rabbits by a stab with a scalpel into the supraspinatic muscle. The changes in the healing process were sonographically followed and documented for 2 months in short periods of time. The sonographically detectable changes during the healing process underlie a regularity. The changes in sonography can be explained by histopathology with respect to the theoretics of ultrasound physics. The development of a hematoma and of fibrous scars can be followed up by sonography with respect to some limits. Sonography is shown to be a supporting method of high value in the diagnosis of muscle injuries and with respect to certain limits in the follow-up of the healing process, too.