Biomedical subjects
W H Castro
Publications and source records attributed to W H Castro.
[Long-term results in revision surgery following lumbar disk nucleotomy]].
In 6.26% of 846 patients with lumbar disc surgery a reoperation was necessary. A total of 93 patient had undergone a revision surgery inclusive a patient group with primary surgery performed elsewhere. 68 patient had 1 reoperation, 22 patients 2, 2 patients 3, and one patient had even 4 revisions. Follow-up ranged between 19 and 42 years with an average of 31 years. 53 patients were clinically examined at a time of follow up and another 15 patients answered a questionnaire. An excellent result with no complaints and patients able to work could be achieved in only 16%. A good result with no radicular pain, but some minor back pain and some loss of sensibility and ability to work was found in 24%. In 40% of the patients the result was only fair with some radicular pain and limited capability for work. 20% of the patients had only a poor result with unchanged symptoms and continued therapy. Those patients were not able to work. Young and female patients had a better prognosis. Another positive predictor was a short period of preoperative pain. Negative predictors were multiple prior operation as well as scar tissue at time of revision. Also spondylodesis according to Cloward correlated also with a negative clinical outcome.
[Surgical treatment of idiopathic thoracolumbar scoliosis: Contrell-Dubousset instrumentation versus ventral derotation spondylodesis].
Especially in idiopathic thoracolumbar scoliosis the approach and sort of instrumentation have controversially been discussed over the past years. Since 1986 32 patients with adolescent thoracolumbar scoliosis underwent operative treatment, 20 patients were treated with Cotrel-Dubousset Instrumentation (CDI), 10 patients underwent Ventral Derotation Spondylodesis (VDS). In 2 cases a combined two-stage VDS and CDI were performed. The follow-up was 38 months in the CDI-group and 19 months in the VDS-group. Length of the curve and the fusion were identical in the VDS-group. In the CDI-group, however, length of the fusion exceeded curve length by 4 segments on average. With CDI the fusion was carried down to L4 in most cases, in some cases to L5. Curve correction of the primary curve averaged 70% with VDS (preoperative mean 84 degrees) and 64% with CDI (preoperative mean 65 degrees). We observed a spontaneous correction of the secondary curve of 38% after VDS. With CDI the correction of the secondary curve averaged 42%, however, in secondary curves measuring more than 50 degrees primary and secondary curve were fused. A preoperatively physiological sagittal plane in the CDI-group remained unchanged after operative treatment. With VDS an average kyphosis of the thoracolumbar junction of +22 degrees was corrected to +7 degrees. We conclude that in the operative treatment of severe thoracolumbar scoliosis VDS offers significant advantages compared to CDI and should therefore be preferred. In moderate scoliotic deformities, where the number of caudally unfused segments is equal in both systems, CDI is justified.
[Function of the glenohumeral ligaments in active protection of shoulder stability].
UNLABELLED: We harvested the joint capsule, the glenohumeral ligaments, and the coracohumeral ligaments of 8 fresh formalin-preserved shoulder specimen. We made use of the van Gieson technique and a special silver impregnation for staining peripheral axons according to Nowotny. The ligaments were cut into slices with a thickness of 15 microns. In total we performed 10,000 cuts. We discovered axons in all ligaments. These axons had no relation to vessels or vessel walls. Besides these axonal structures we detected type II mechanoreceptors (Pacini receptor). CLINICAL SIGNIFICANCE: The neural structures discovered in the glenohumeral capsule are of clinical importance especially in consideration of the high account of recurrent shoulder dislocation and concomitant Bankart lesions. Receptors located in the glenohumeral ligaments might control the stabilizing shoulder musculature. On this premises, rupture or detachment of these ligaments will lead to a loss of the feedback mechanism.
[Homologous blood use and possibilities for autologous hemotherapy as exemplified in hip and knee endoprostheses].
In a retrospective study we documented the need for blood transfusion in total knee (TKR) and hip replacement (THR). The problems with homologous blood transfusion in orthopedic surgery and alternative techniques of autologous-blood transfusions are discussed. In this series patients with primary THR needed 1.69 (+/- 2.25) blood units, with primary TKR 1.58 (+/- 1.54) blood units, and secondary TKR 1.19 (+/- 1.47) blood units, Secondary THR required significantly more units (3.85 +/- 3.07). These procedures also asked for significantly more plasma (3.27 +/- 3.95) than all other procedures. For secondary THR 2.63 (+/- 2.45) blood units were intraoperatively used and only 1.23 (+/- 1.09) blood units postoperatively. All other procedures needed postoperatively significant more units than intraoperatively. In secondary THR the use of blood transfusions increased with age. 45% of the patients with primary THR and 15% with secondary THR were operated without additional blood transfusion. In secondary THR 36% of all patients needed more than 4 blood units and 27% more than 4 plasma units. In TKR 39% of the primary cases and 50% of the secondary cases were operated on without additional homologous blood. Based on these results we established a transfusion concept for our department. Economic, practical, as well as legal aspects were taken into account.
[The function of passive stabilizers of the glenohumeral joint--a biomechanical study].
UNLABELLED: In a biomechanical study we evaluated the passive stabilizing ligaments of 9 fresh shoulder specimens with mercury bands. While preparing the specimens we found two interesting entities: there are fibers of the coracohumeral ligament running from the humeral head to the coracoacromial ligament and there was an reproducible thickening in the posterior joint capsule. Functional evaluation shows that the coracohumeral ligament limits external rotation independently of the amount of abduction as well as inferior subluxation. The mediale glenohumeral ligament shows the highest tension in external rotation and 30 degrees abduction. The anterior inferior ligament strengthens the joint capsule in abduction and external rotation. The posterior inferior ligament shows the highest tension in abduction and internal rotation. CLINICAL RELEVANCE: Immobilization in internal rotation and adduction may lead to shortening of the coracohumeral ligament, which may result in severe limitation of external rotation and abduction. Resection of the coracoacromial ligament relaxes the coracohumeral ligament leading to an increased cranio-caudal instability. The posterior inferior ligament is complementary to the anterior inferior ligament thus stabilizing the shoulder joint in abduction and internal rotation. Sparing this structure in arthroscopy with dorsal portals and restoring in the case of a rupture seems to be of value for a normal joint function.
[How much intervertebral disk tissue is in reality removed in percutaneous nucleotomy?].
In an experimental study with standardized conditions nuclear material of 40 human lumbar discs was excised. In 20 the non-automated discectomy method was used (NAPLD-method). In the other 20 the automated discectomy method (APLD-method). The excised material was weighted. After the removal, the material of the NAPLD-method was wet with isotonic saline over 45 minutes and again weighted. Afterwards the wet material of both methods was freeze dried and again weighted. The weight of the wet material of the NAPLD-method in relation to that of the freeze dried material was a factor 11 (average value: 7.7 g in relation to 0.7 g) and in the APLD-method a factor 15 (average value: 4.5 g in relation to 0.3 g). This means, that the uptake and distribution of the saline is different in both methods and for this reason it is not allowed to compare the wet weight of the two methods. This has to be considered in clinical comparative studies. Because the biomechanical changes after a discectomy are dependent of the amount of the excised nuclear material, the NAPLD- and APLD-method can only be compared when the amount of the excised material is changed in a freeze dried weight.
[Changes in the lumbar disk following use of non-automated percutaneous discectomy. A biomechanical study].
For a biomechanical study 8 specimens of the lumbar spine (L1-S1) were scanned with MRI. After that 21 motion segments were prepared for the experiments. The paraspinal musculature as well as the posterior elements were removed. From each disc 1,0 g, 2,0 g, and 3,0 g of nuclear material were consecutively removed under an axial load of 500 N. At the beginning of every standardized experiment of a motion segment, as well as after the excision of every gram of nuclear material, intradiscal pressure, the height of the disc and the contour of the disc were determined with an axial load on the motion segment of 1000 N. The change in radial bulging of the disc was measured using the computer-assisted recordings of each disc contour. All the data were statistically analyzed using the Friedman-test. The nuclear material removed from the discs ('in-vitro nuclear material') was placed in isotonic saline over 45 minutes and again weighted ('wet weight'). Af that the nuclear material was freeze-dried ('dry weight'). The results of this study showed that after the excision of every gram of nuclear material the height of the disc decreased in average 0,77 mm. Also intradiscal pressure reduces significantly: from the initial stage, on average, 9, 19 bar to the endstage (= after the removal of 3,0 g), on average, 2, 58 bar. Radial bulge increases with every gram removed, on average 0,23 mm. The weight of the wet nuclear material is 2,6 times as much as that of the in-vitro nuclear material and 11 times as much as that of the freeze-dried material.
[Accuracy of pedicle screws following instrumented dorsal fusion of the lumbar spine].
We evaluated the placement of pedicle screws (N = 131) in 30 patients after lumbar dorsal spinal fusion. Postoperatively all patients were examined by CT. 39.9% of all screws penetrated the cortex of the vertebra. Of special interest were those implants which led to medial penetration of the pedicle, which is of potential hazard to the neural structure within the nerve root canal. 28.5% of all screws showed a medial deviation. In our study, a penetration of more than 6 mm coincided with a high risk for nerve root damage. In 2 patients there was proven damage to a nerve root due to screw placement. In another 3 patients coherence was likely to exist. The technique of transpedicular screw fixation for spinal fusion is highly demanding and should be performed only by experienced surgeons after a clear indication and after a trial of intense conservative therapy.
[Long-term results of the surgical treatment of spondylolisthesis using Schöllner's sacral plate].
Treatment of spondylolisthesis is discussed differently even nowadays. In addition to that long term results of surgical reduction and stabilization by internal fixation are rare. Therefore the evaluation of the data of 61 patients treated operatively with the sacral plate by Schöllner with a mean follow-up of more than 10 years seemed to be justified. Additionally 48 out of 61 patients could be reexamined at follow-up and answered a questionnaire to measure their subjective status. Mean age at the time of surgery averaged almost 18 years. 14 male and 47 female patients were treated. Sagittal translation averaged 66% and was corrected to a mean 31%. Sagittal rotation was corrected approximately 70%. Preoperative neurological deficits could be treated successfully in most of the cases. However, in 5 cases irreversible neurological lesions of the L5 nerve root occurred. Early revision surgery was indicated three times each in cases of implant loosening and distal plate pull-out. 4 of 5 patients underwent additional surgery due to pseudoarthrosis. At follow-up 75% of the patients were pain free, another 22.9% experienced improvement of at least 80%. 47 out of 48 patients were very satisfied or satisfied with the result of the operation. In our mind the long term results justify operative reduction and stabilization of spondylolisthesis by internal fixation for improvement of static, function and symptoms. Possibilities to reduce complications are discussed.
[Long-term changes in proton spin tomography following chemonucleolysis].
6.5 years after lumbar chemonucleolysis (CNL) we examined 40 patients by MRI. All MRI studies were performed by a 1.0 tesla MRI. We documented the height of the discs, the chondrosis, the intradiscal MRI signal, as well as the intraosseous signal within the vertebral bodies (end plate reaction). Preoperative MRI studies (Tvor) and/or postoperative MRI studies within the first postoperative year (T1) of 18 patients were available. We found an overall reduction of the sagittal disc height of 26%. This reduction was 19% in the male patients and 45% in the female patients (p < 0.02). Comparing the T1-studies with the T6.5-studies, we could still reveal a proceeded reduction of 13%. In those patients who underwent three MRI studies, there was a reduction of 20% between Tvor and T1. Among one half of the patients we found a further decrease in disc height of 15% between T1 and T6.5, whereas the other half showed an increasing disc volume of 15%. At time of follow up (T6.5) all treated discs showed a reduced MRI signal (STIR) within the disc. The signal further decreased comparing the MRI signal (STIR) preoperatively with the follow up evaluation in 64.3% of the cases. However, we found an increase of the signal in 70% of the cases between T1 and T6.5. 6.5 years after CNL we documented an end plate reaction in almost 70% of all patients. There was no correlation between end plate reaction and age of the patients, level of CNL, amount of injected chymopapain or the clinical outcome.
[Arthroscopic resection of the shoulder joint (Mumford operation)].
Based on results of anatomical studies, we established an arthroscopic procedure to resect all degenerative changes within the joint without endangering the stabilizing structures. Since November 1989 we operated on 26 patients with this technique. There were no major complications. The mean score significantly increased from 64.9 (+/- 12.8) to 86.8 (+/- 11.5). Analysis of postoperative x rays revealed an average length of resection of 21.3 mm at the inferior border of the clavicle, of 15.4 mm in the middle, and of 10.2 mm at the superior border of the clavicle. 21 out of 26 patients were completely satisfied and would undergo the same procedure again. In two of the five unsatisfied patients the resected length of the clavicle was insufficient and these patients required open surgery for resection of the remaining bone. Our first experiences are encouraging. The surgical technique is standardized and reproducible. The short time results score not worse compared to the open conventional technique. With the 2 to 4 year long term follow up we have to prove, whether maintaining the passive stabilizers of the joint improves the long term results better than the open technique.
[Correlation of the degeneration of the AC joint (acromioclavicular) and rupture of the rotator cuff].
During the past various factors were quoted to be causative of a degeneration of the rotator cuff. In this study 122 shoulder specimen, aged 58-95 years, were dissected. A high correlation between severe degeneration of the ac-joint and rupture of the rotator cuff was found. The correlation was even higher between distally pointing osteophytes and cuff ruptures. The results demand to clearly define the degeneration of the ac-joint and the rotator cuff in patients suffering from shoulder pain. A simultaneous occurrence has to be considered. If conservative treatment fails in patients with cuff tear and ac-joint degeneration, surgical revision is recommended. This should comprise: 1. suture of the cuff-rupture 2. excision of the coraco-acromial ligament 3. anterior acromioplasty according to Neer 4. excision of the outer end of the clavicle
[Stress on the rotator cuff sutures in relation to joint position].
UNLABELLED: In a vitro study we evaluated the influence of surgical technique on the postoperative tension of the supraspinatus tendon in rotator cuff ruptures. In ten shoulder specimens Hall-Effect Strain Gauge (HEST) were implanted in the supraspinatus tendon close to the insertion at the humerus. We documented the tension in specimens with intact rotator cuff as well as after reconstruction of small and large tears in different joint positions. In the specimens with an intact rotator cuff there was almost no tension registered. Only in adduction with external rotation and flexion we found slightly increased values. After reconstruction we found the highest tension in adduction, flexion, and external rotation of the humerus. Release of the coracohumeral ligament resulted in a decrease of tension in flexion and external rotation. Whereas in extension coracohumeral ligament release had no influence on the tension of the tendon. However, after complete capsule release the tension in extension also decreased. CLINICAL RELEVANCE: If mobilisation in cases of rotator cuff reconstruction is necessary we recommend first release of the coracohumeral ligament in small and moderate tears. In major tears a complete capsule release is necessary. During physical therapy in the early postoperative course, flexion in the adducted and externally rotated arm should be avoided.
[Changes in the lumbar intervertebral disk following use of the Holmium-Yag laser--a biomechanical study].
For a biomechanical study 10 specimen of the lumbar spine (L1-S1) were scanned with MRI. After that 18 normal motion segments were prepared for the experiments. The paraspinal musculature as well as the posterior elements were removed. Under an axial load of 500 N, in each disc 500 J and 1000 J of energy were applicated with a Holmium-Yag laser (2060 nm, fiber thickness 600 microns) into the nucleus pulposus. In nine of the 18 discs also 1500 J and 2000 J were applicated. At the beginning of every standardized experiment of a motion segment, as well as after every 500 J, the height of the disc, intradiscal pressure, the contour of the disc and the size of the transversal plane of the disc were determined with an axial load on the motion segment of 1000 N. The change in radial bulging of the disc was measured using the computer-assisted recordings of each disc contour. All the data were statistically analyzed using the Friedman-/Wilcoxon-test. After every application of 500 J energy, in the 18 discs as well as in the 9 discs, the height and the intradiscal pressure reduced. The differences per 500 J were for all measurements not significant (p < 0.05). Up till the application of 1500 J the radial bulge and the size of the transversal plane of the disc increased, although the differences per 500 J were not significant. From 1500 J to 2000 J the radial bulge and size of transversal plane of the disc decreased.(ABSTRACT TRUNCATED AT 250 WORDS)
[Compartment pressure of the anterior tibial area in jogging].
31 healthy persons had to run on a treadmill under defined conditions at a constant speed of 8 km/h. Pressure in the anterior flexor-muscles compartment was measured regulary in time before, during and after running; the size of the compartment was documented by sonography. The measured pressure was attached to the respective compartment size. The runners were divided into three groups based on characteristic pressure-courses: the normal-type with average values below 50 mmHg, the indifference-type with a distinctly higher pressure than 50 mmHg and the risk-type with values more than 70 mmHg. A correlation between exercise-pressure and time of post-exercising decrease of pressure was found. While the normal type reached the starting pressure within 6 minutes the indifference and risk type didn't succeed in decreasing after this period of time. No change of compartmental size was measured while the pressure increased on exertion.
[Intravenous administration of gadolinium DPTA in proton spin tomography of the knee joint].
UNLABELLED: In a prospective study we evaluated the benefits of iv-application of gadolinium-DPTA examining 25 patients with degenerative disease of the knee joint by MRI (1.0 Tesla). All patients were scanned with standard spin echo sequences (SE 500/20), short time inversion recovery sequences (STIR 1600/100), and FEDIF sequences (FEDIF 500/10). After gadolinium-DPTA application (0.1-0.35 mmol/kg BW) the patients were scanned with spin echo sequences (SE SE 500/20), and FEDIF sequences (FEDIF 500/10). After iv-Gadolinium the synovial membrane of joints with inflammation show significant increase of the signal. Due to this effect a differentiation between joint effusion and hypertrophic synovia is possible. Small areas of local synovitis not visible before the use of gadolinium can be documented. A differentiation between degenerative subchondral cysts and cysts due to an inflammatory process is possible. CLINICAL RELEVANCE: The use of iv-application of gadolinium-DPTA in patients with degenerative joint disease seems to offer additional information. With iv-application all shortcomings of intraarticular use can be avoided. The differentiation between degenerative and inflammatory processes is possible.
[Long-term results following percutaneous facet coagulation].
UNLABELLED: 93 patients with a mean follow up of 73 months (30-133 months) after lumbar percutaneous radiofrequency denervation (PRFD) were evaluated. Mean age of the patients at time of surgery was 47 years (18-76 years). 54 patients had no lumbar spine surgery prior to facet denervation, 32 patients had one or multiple disc surgery prior to denervation, and 7 patients had spinal fusions. 51 patients were in the process of early retirement or already retired at time of surgery. Out of all 93 patients only 50% had significant pain relief immediately after PRFD. 3 months after PRFD the success rate dropped down to 38%. 6 years after surgery only 25% of all patients had long lasting good results. Patients who were pain free after facet infiltration had significant better initial results, but were similar to the others after 6 years. 6 out of 7 patients after lumbar spinal fusions demonstrated bad results. The worst results had those patients who had applied for early retirement (workmens compensation cases). In this group the recurrence rate was 74% 6 years after surgery. We found no correlation between the surgeon and the outcome. CLINICAL RELEVANCE: Without pain reduction after facet infiltration the success rate after PRFD is low. Spinal surgery prior to PRFD significantly reduces the success rate. The worst prognosis have workmans compensation cases. The recurrence rate is high within the first 6 months after PRDF.