Wachstumsverhalten humaner mononukleärer Zellen aus dem Knochenmark und Nabelschnurblut auf einem Kollagenträger zur osteogenen Regeneration / Growth Behaviour of Human Mononuclear Cells Derived from Bone Marrow and Cord Blood on a Collagen Carrier for Osteogenic Regeneration

We investigated the biocompatibility and osteogenetic potency of a porcine collagen I/III carrier in a human bone marrow and cord blood cell culture system.

METHODS

Human mesenchymal mononuclear cells were isolated from cord blood and iliac crest bone marrow and cultivated in various cell densities on a semipermeable porcine collagen I/III carrier. After 14 days of in vitro cultivation both cultures were subjected to osteogenic stimulation by dexamethasone, ascorbic acid and beta-glycerol phosphate (DAG) until day 40. Semiquantitative immunochemical evaluation based on osteoblastic and progenitor cell markers was then done.

RESULTS

With regard to the minimal local cell density required for growth and osteogenic differentiation, cord blood derived progenitor cells showed lower tolerance in comparison with bone marrow derived cells. For both cell culture systems three-dimensional growth and calcification within the collagen fibres were seen after osteogenic stimulation.

CONCLUSION

Human cord blood and bone marrow derived mesenchymal stem cell are capable of differentiating into osteoblasts after incubation with a collagen I/III biomaterial.

[Ultrasonographic evaluation of the rotator cuff after shoulder arthroplasty]

AIM

Ultrasonography of the rotator cuff tendons is a standard imaging technique. Although increasing numbers of shoulder arthroplasty are performed, there is no available data concerning the use of ultrasound after shoulder replacement. Our experimental study was performed to analyse the value of ultrasonography after shoulder arthroplasty a) in an ex-vivo-setting and b) in a retrospective analysis of our patients after shoulder hemiprothesis.

METHOD

After defrosting, anatomic modular humeral head replacement was performed in four fresh-frozen specimens with intact rotator cuffs. The supraspinatus and subscapularis tendons of each specimen were either detached to simulate a cuff defect or reattached anatomically (four times per specimen). Two experienced examiners then performed ultrasonography to evaluate the two tendons to be either intact or deficient. In a retrospective study, 22 patients with 25 hemiprotheses of the shoulder underwent clinical and sonographic examination. For documentation of the clinical findings, the Constant score was used.

RESULTS

In the cadaver study, the reliability of the method was slightly higher for the subscapularis tendon (13 correct, 3 false results) than for the supraspinatus tendon (12 correct, 4 false results). In our patients, rotator cuff defects and effusions around the biceps tendon and in the subdeltoid bursa could be detected. Normal sonograms correlated with good clinical results.

CONCLUSION

In the cadaver study, we found a good reproducibility of in-vivo conditions. We believe that ultrasonography is beneficial in follow-up evaluation after shoulder arthroplasty.

The DNA sequence and analysis of human chromosome 6

Chromosome 6 is a metacentric chromosome that constitutes about 6% of the human genome. The finished sequence comprises 166,880,988 base pairs, representing the largest chromosome sequenced so far. The entire sequence has been subjected to high-quality manual annotation, resulting in the evidence-supported identification of 1,557 genes and 633 pseudogenes. Here we report that at least 96% of the protein-coding genes have been identified, as assessed by multi-species comparative sequence analysis, and provide evidence for the presence of further, otherwise unsupported exons/genes. Among these are genes directly implicated in cancer, schizophrenia, autoimmunity and many other diseases. Chromosome 6 harbours the largest transfer RNA gene cluster in the genome; we show that this cluster co-localizes with a region of high transcriptional activity. Within the essential immune loci of the major histocompatibility complex, we find HLA-B to be the most polymorphic gene on chromosome 6 and in the human genome.

Prevalence of multiple endocrine neoplasia type 1 in young patients with apparently sporadic primary hyperparathyroidism or pancreaticoduodenal endocrine tumours

Background

The appropriate treatment for a sporadic endocrine tumour may be different from those that present as part of the multiple endocrine neoplasia type 1 (MEN1) syndrome. As primary hyperparathyroidism (pHPT) and pancreaticoduodenal endocrine tumours (PETs) are the most common organ manifestations of MEN1, the prevalence of germline mutations in the MEN1 gene was determined in young patients with apparently sporadic pHPT or PETs.

Methods

Eighteen of 705 patients with pHPT and 11 of 93 patients with PETs operated on between 1987 and 2001 had no family history of MEN1, only one organ manifestation and were aged 40 years or less at the time of diagnosis. Fifteen patients with pHPT and eight with PETs agreed to MEN1 gene mutation analysis, which was performed by single-strand conformational variant analysis and direct DNA sequencing.

Results

Two of 15 patients (13·3 (95 per cent confidence interval (c.i.) 1·6 to 40·4) per cent) with apparently sporadic pHPT had a MEN1 germline mutation. Both mutations were found in patients with pHPT due to multiglandular disease, whereas the remaining 13 patients had a solitary adenoma. None of the eight patients with PETs carried a MEN1 germline mutation.

Conclusion

Sporadic pHPT due to multiglandular disease in patients younger than 40 years may represent the first organ manifestation of MEN1 despite a negative family history.

Osteonekrose und HELLP-Syndrom

BACKGROUND

In 25 % of patients who develope gestosis a Hemolysis- Elevated- Liver-enzymes-and- Low- Platelet-count-Syndrome (HELLP-Syndrome) may occur, which is characterized by activation of the coagulation mechanism and bone marrow alterations. Besides this therapeutical steroid application and an elevated age of primigravidity are responsible for an increased osteonecrosis risk in women, too. Because of anatomical and biomechanical reasons the highest incidence of pregnancy-associated osteonecrosis are the subchondral areas of the femoral epiphysial head.

PATIENTS/METHODS

In this investigation data of pathogenesis, diagnostic work up and therapy in HELLP-associated osteonecrosis are reviewed and discussed based on a case report. We report of a 37-year old HELLP-patient showing bilateral femoral head osteonecrosis, who sustained a proximal femur fracture after bone marrow core decompression surgery.

RESULTS/CONCLUSIONS

In pregnant patients with joint or bone associated pain an early MRI screening is recommended to detect osteonecrosis at early stages. This allows for therapeutic procedures which may be successful at early stages. If steroids are applicated for HELLP-treatment, the risk of osteonecrosis is elevated.

DISCUSSION

Only early stages of osteonecrosis can be treated curatively. Sometimes it can be difficult to differentiate between early osteonecrosis stages, a bone marrow edema syndrome and a transient osteoporosis.

Magnetic resonance imaging after reduction for congenital dislocation of the hip

BACKGROUND

Reliable concentric reduction of the femoral head and subsequent retention in a centred position are indispensable preconditions for the remodelling of the acetabulum in developmental dysplasia of the hip (DDH) and to prevent damage to the hip joint, i.e. avascular necrosis. The objective of this study is to evaluate the necessity of verifying the reduced position of the articulation in the plaster cast.

METHOD

MRI was carried out in 15 infants with 21 unstable hip joints after reduction under arthrographic control and fixation in a plaster cast in the 'human' position with the hips flexed above 90 degrees and abducted to 50 degrees or 60 degrees. When the reduction was found to be inadequate-the hip still partially or completely dislocated-the plaster cast was removed, reduction repeated, a new cast applied, and MRI carried out again.

RESULTS

After primary reduction, 1 of 21 hips was dislocated, and 2 showed unsatisfactory reduction. Three hip joints out of 21 (14.3%) were not fixed in the plaster cast in the optimal centred position.

CONCLUSION

In view of the number of inadequate reductions in plaster casts, we recommend verifying the position of the hip joint by MRI. This MRI documentation should be established as a standard examination post-reduction.

[Kyphoscoliosis in Wiedemann-Rautenstrauch-syndrome (neonatal progeroid syndrome)]

AIM

The Wiedemann-Rautenstrauch syndrome (neonatal progeroid syndrome, WR syndrome) is a rare autosomal recessive disorder including premature aging already at birth. Most of the patients show an aged face, a craniofacial dysmorphism, decreased subcutaneous fat tissue, a significant developmental delay, and have a short life expectation. We present the second patient described in literature reaching an age of 16 years. Furthermore this patient developed a progressive scoliosis during childhood which to our knowledge has not been reported before among individuals affected by Wiedemann-Rautenstrauch syndrome. The pathogenetic features of the spinal deformity are discussed and the operative management is described.

METHOD

The patient underwent a three-stage correction of her spinal deformity (anterior thoracic and lumbar release and posterior release, correction of the deformity with instrumentation and fusion) supported by Halo traction and physiotherapy.

RESULTS

At the latest follow-up 12 months postoperatively the patient showed a stable correction from 78 degrees to 38 degrees in the frontal plane with physiologic sagittal alignment both clinically and radiologically.

CONCLUSION

The scoliosis of our patient with Wiedemann-Rautenstrauch syndrome showed radiologically and clinically the characteristics of a neuromuscular curve. Since the curve showed a significant progression and high rigidity operative correction and fusion was indicated. We recommend a staged operative management to minimize the high risks of the operations and possible complications from cardiological and respiratory dysfunction associated with WR syndrome.

[Nonoperative treatment in Legg-Calvé-Perthes disease]

There is still discussion about the indication for and modalities about treatment of Perthes'disease. The main objective of treatment in Perthes'disease is prevention of deformation and malalignment of the hip joint. Most important for the evaluation of any therapy is the long term outcome, therefore we present this retrospective study on nonoperative treatment of perthes disease with orthoses compared to the natural history. 54 Patients with 59 involved hips, treated between 1945-1975 were clinically and radiologically evaluated. We divided the patients into two subgroups: Group 1 with nonoperative therapy. Group 2 with no therapy. The outcome shows correlation of the results with the degree of malalignment and necrosis. There was no statistically significant correlation between the two groups, but a slightly better outcome in the non-operative group compared to the natural history. The use of orthosis may be justified if there is improvement of the containment and reduction of the femoral head, otherwise surgical treatment like pelvic- and hip osteotomies to realign the hip joint should be considered.

[One- or two-step instrumentation for thoracolumbar scoliosis due to myelomeningocele?]

AIM

This investigation evaluates patients with MMC who underwent a two-stage anterior-posterior correction and stabilisation of thoracolumbar scoliosis due to myelomeningocele. The data were compared with the few reported series of one-stage versus two-stage surgery in the literature.

METHOD

From 1.7.1992 to 30.6.1995, 11 consecutive patients with severe thoracolumbar scoliosis due to myelomenigocele were admitted at our hospital. The mean age at operation was 12 years nine months (range nine years nine to 14 years six months). All patients underwent a two-stage anterior and posterior spinal instrumentation. The patients were pre- and postoperatively evaluated.

RESULTS

All patients were followed for a mean of 4 years 11 months (range 42 months to 88 months) from the time of the second stage procedure. Preoperatively the mean scoliosis angle was 82 degrees (range 55 degrees to 110 degrees ), this was reduced to a mean of 31 degrees (range 8 degrees - 70 degrees ), at final follow-up, the correction had deteriorated slightly to a mean of 35 degrees (range 12 degrees - 80 degrees ). No patient had increased neurological deficit or showed other major complications, i. e., infection, sepsis due to immunologic disorders at the time of the operation.

CONCLUSION

We believe that with the two-stage anterior and posterior instrumentation an effective correction of the scoliosis can be achieved. Compared to other studies this report confirms the low morbidity rate and emphasise the good results of a two staged procedure.

Surgery versus surveillance of pancreaticoduodenal endocrine tumours in multiple endocrine neoplasia type 1

Background

Management of pancreaticoduodenal endocrine tumours remains controversial in multiple endocrine neoplasia type 1 (MEN1). The authors' experience with MEN1-related pancreaticoduodenal tumours has been reviewed in order to evaluate a rational therapeutic approach.

Methods

Twenty-one patients with MEN1 with pancreaticoduodenal endocrine tumours were analysed with special regard to outcome of surgery and surveillance. In addition, a phenotype/genotype analysis was performed based on MEN1 gene mutation analysis.

Results

Twelve of 21 patients had multiple tumours. Nine patients had gastrinomas, six non-functioning tumours, three insulinomas, two insulinomas and gastrinomas, and one had a vipoma. Six tumours were malignant with lymph node metastases (five gastrinomas, one vipoma). Seventeen patients were treated initially by either pancreatic left resection with tumour enucleation of the duodenum and/or pancreatic head (n = 9), tumour enucleation alone (n = 7) or pylorus-preserving partial pancreatectomy (PPPD; n = 1). Sixteen of 17 patients were cured biochemically after initial surgery and 11 remained free of disease after a median follow-up of 55 (range 2–197) months. Six patients underwent reoperation for recurrence and/or lymph node metastases, including two PPPDs in patients with gastrinoma. All six patients remained asymptomatic and three remained biochemically free of disease. Three of the 17 operated patients died from either unrelated causes (n = 2) or postoperative complications (n = 1). On the other hand, four asymptomatic patients with either gastrinomas (n = 2) or non-functioning tumours (n = 2) were closely surveyed and showed no progress or metastases on somatostatin (SMS) scans and computed tomography after 9–110 months. The genotype/phenotype analysis revealed that patients with truncating nonsense or frameshift MEN1 gene mutations in the N- or C-terminal regions (exons 2, 9 or 10) had a significantly higher rate of malignant tumours (55 versus 8 per cent; P = 0·04) and tended to have shorter disease-free intervals (28 versus 120 months; P = 0·11) than patients with other mutations.

Conclusion

An aggressive surgical approach is justified for pancreaticoduodenal tumours in patients with MEN1 since symptom-free long-term survival can be achieved. However, MEN1 gene mutations in exons 3–8 seem to be associated with mild behaviour of pancreaticoduodenal tumours which might allow close surveillance in asymptomatic patients with MEN1.

Randomized controlled trial of standardized meal stimulation for the detection of enteropancreatic endocrine tumours in patients with multiple endocrine neoplasia type 1

Background

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterized by the occurrence of hyperparathyroidism (approximately 100 per cent), and pituitary (approximately 40 per cent) and enteropancreatic endocrine (approximately 70 per cent) tumours. It has been suggested previously that serum pancreatic polypeptide and serum gastrin after standardized meal test stimulation are useful indicators for early identification of enteropancreatic tumours in MEN1. Therefore the usefulness of the meal test was evaluated in a screening programme of MEN1 mutation carriers.

Methods

In a prospective, controlled trial between September 1997 and December 1995, 55 standardized meal stimulation tests (563 kcal) were performed in 13 MEN1 mutation carriers with no evidence of enteropancreatic tumours (group 1); ten patients with MEN1 with histologically, biochemically and radiologically evident enteropancreatic tumours (group 2); and in 28 healthy adults for control (group 3). Genetic analysis was done by single-strand conformation analysis and direct sequencing. Serum pancreatic polypeptide and serum gastrin levels were measured by radioimmunoassay (Ideon, Sweden). Data were analysed using analysis of variance (Kruskal–Wallis test, 2 d.f.) and Mann–Whitney test.

Results

Median (range) basal serum pancreatic polypeptide levels were 214 (38–897) pg ml−1 in group 1, 126 (13–263) pg ml−1 in group 2 and 73 (13–357) pg ml−1 in group 3. Median (range) serum gastrin levels were 103 (37–391), 551 (25–4080) and 65 (17–198) pg ml−1 respectively, but gastrin levels in group 2 were strongly influenced by patients with known gastrinoma. Levels of both variables increased after meal stimulation in all groups. However, there was no significant difference between the groups after stimulation (P > 0·05).

Conclusion

Standardized meal stimulation test does not reliably indicate the presence of enteropancreatic endocrine tumours in patients with MEN1. It is not therefore used in the authors' routine screening programme for patients with MEN1.

[Fracture analysis of a ceramic liner. Is in hip endoprosthesis replacement of ceramic on ceramic components with only one of the corresponding partners justified?]

The good biomechanical and tribological properties, together with the excellent biocompatibility, of ceramic-on-ceramic components, make them a preferential choice for total hip replacement surgery, at least in Europe. We report on a man admitted as an outpatient with painless grating in the hip one year after replacement of a ceramic femoral head, but not of the ceramic inlay. Clinical and radiological findings were indicative of a broken liner. This was confirmed during revision surgery, during which it was replaced by a polyethylene inlay; although the ceramic head appeared intact, it was replaced by a metal head. Inspection of the surface of the broken liner in the scanning electron microscope (SEM) revealed signs of material failure. We recommend careful inspection of ceramic-on-ceramic articulating components during total hip revision surgery and if there is any uncertainty, replacement of both so as to avoid premature failure.

The value of ultrasound after shoulder arthroplasty

OBJECTIVE

This study was undertaken to evaluate whether sonography is a useful tool in the diagnosis of soft tissue disorders as a possible cause for discomfort and/or pain after shoulder arthroplasty.

DESIGN AND PATIENTS

Static and dynamic ultrasound examinations were performed in the standard sectional planes on 22 patients with 25 hemiprostheses and the results were correlated with the clinical outcome. The stability was determined in the transverse and frontal planes and the clinical results were evaluated according to the Constant and Swanson scores.

RESULTS

Several pathological changes were detected: rotator cuff lesions, subdeltoid bursitis, changes around the long biceps tendon as well as an increase in intra-articular volume due to effusion and/or synovitis. The correlation of sonographic and clinical results demonstrated that patients with an excellent clinical result showed no or only a few pathological findings on sonography compared with those with a moderate or poor result.

CONCLUSION

Pathological changes of the periarticular tissue in the direct neighbourhood of the implant can be detected by sonography, which can be recommended as a valuable examination technique to evaluate the soft tissue in patients after shoulder arthroplasty.

[Advantages of biomatrices in chondrogenesis of pluripotent mesenchymal stem]

AIM

The autologous in vitro expansion of chondrocytes is a new method for the treatment of localized cartilage defect zones in humans. In the past several investigators have shown the occurrence of mesenchymal stem cells (MSC) in human bone marrow, periosteum and somite mesoderm. Moreover it has been shown that these progenitor cells are able to differentiate into chondral tissue under special in vitro conditions. The following study shows current possibilities and borders of a chondrogenetic stem cell therapy. Furthermore advantages and disadvantages of different cellular biomatrix carriers are described, cartilage tissue engineering-related problems are discussed and possible solutions were pointed out.

METHODS

A literature investigation served for evaluation of the present clinical and experimental data. Furthermore our own cell culture experiences were considered.

RESULTS

Until now there exists no clinical concept using the potential of MSC for cartilage tissue engineering. Reasons are the lack of biomechanical and histological stability and handling problems of the cultivated cartilage tissue, especially the difficulties to fix and secure the transplant in the cartilage defect zones in situ.

CONCLUSION

The systematic investigation of biomatrices by chondrogenic progenitor cell culture systems may lead to important data for the evaluation of the chondrogenic potency biomatrices.

A new technique for the surgical management of deformities in the growing spine

The Luque procedure was developed to correct the deformity without the need of bracing and maintaining that correction with growth. However many authors are disappointed by their results and the complications which appear in the management of infantile scoliosis with Luque trolley alone. Besides failed implants, pseudarthrosis, modest spinal growth and protuberant rods and wires, the major problem of the Luque systems is the high incidence of loss of correction by postoperative rotation. Therefore a new application technique is recommended. A standard posterior extraperiostal approach is chosen. Sublaminar titanium cables are passed at each level except the caudal lamina. Then the rods are precontoured in shape of the planed curve correction. We use a low profile titanium instrumentation with 5.0 mm diameter rods and 4.2 mm pedicle screws. In contrast to the conventional use of two antiparallel "L"-rods we recommend the use of one reversed "U"-rod securing the laminae with sublaminar titanium cables of the upper end vertebrae. For fixation of the lower spine a dual-opening pedicle screw system is used. Using a holding forceps the distal rods are introduced and fixed into the side opening of the screws then secured by sublaminar wires. In addition both single rods are stabilized by a low profile cross link bar. This technique allows to correct pelvic obliquity and a stable anchorage of two screws reduces risk of postoperatively rotation or caudal rod slippage due to gravity forces.

[Medical-legal aspects in fractured ceramic liners after implantation of a hip endoprosthesis]

We report the case of a male patient after implantation of a thrust plate endoprosthesis to discuss reliable questions concerning the insurance and liability fields. The indication for implantation of this type of endoprosthesis should be decided critically. To prevent an early implant failure, both articulating ceramic partners - the liner and the femoral head - should be exchanged in any case of doubt during a hip revision surgery. In case of an implant failure, a surface analysis of the broken fragments can show signs of material insufficiencies. A detailed preoperative consent of the patient combined with an exact documentation is necessary to prevent potential medical claims by the patient, and also increases the compliance and reduces the costs for the health system.

[Clinical and radiological short- and mid-term results of triple pelvic osteotomy according to Tönnis in adolescents and adults]

AIM

We report our clinical and radiological results after triple pelvic osteotomy according to Tönnis and accompanying femoral osteotomies in selected cases.

METHOD

48 patients were evaluated in a retrospective study with an average follow-up to 2 years and 9 months.

RESULTS

In 68 % of our patients excellent to good results in the Harris Hip Score were achieved. We could significantly decrease pain awareness. The CE angle improved significantly from 10.6 degrees to 32.2 degrees and the acetabular angle of the weight-bearing zone according to Bombelli from 20.8 degrees to 3.8 degrees at the last follow-up. The VCA angle according to Lequesne and de Seze improved from 18.6 degrees to 33.5 degrees. Non-union of the ischial or the pubic bone developed in 7 cases as a relevant complication.

CONCLUSION

On the basis of our results and the literature, the triple pelvic osteotomy according to Tönnis can be recommended for the treatment of acetabular dysplasia in adolescents and adults.

Familial ACTH-independent Cushing's syndrome with bilateral macronodular adrenal hyperplasia clinically affecting only female family members

Primary adrenal hyperplasia, which may occur as a familial disorder, is a rare cause of ACTH-independent Cushing's syndrome. In most of these cases the underlying pathology is primary adrenocortical micronodular dysplasia. Very few cases of familial Cushing's syndrome due to primary macronodular adrenal hyperplasia have been described. We report a family with seven affected family members. The pedigree indicates an autosomal dominantly inherited disorder. Interestingly only female family members developed the clinically apparent syndrome. The only available obligatory male gene carrier failed to adequately suppress his plasma cortisol level on overnight dexamethasone suppression test. His adrenal glands showed nodular enlargement on abdominal computed tomographic imaging. Screening of the MEN 1 gene and genetic analysis of the hot spot regions of the GNAS 1 (codons 201 and 227) and GNAI 2 (codons 179 and 205) genes did not show any mutations in the constitutional DNA or the adrenal tissue DNA of the index patient. In conclusion, this family is the largest kindred reported in the literature with ACTH-independent Cushing's syndrome due to autosomal dominant inherited macronodular adrenocortical hyperplasia. Four currently alive and affected family members in two generations and further careful observation of the yet unaffected members of the third available generation might offer the opportunity to identify the still unknown gene defect in the future.

[Primary synovial chondromatosis of the shoulder]

AIM

To demonstrate the various patterns of primary synovial chondromatosis (PSC) around the shoulder and to discuss a therapeutic algorithm.

METHOD

In this retrospective study, 6 patients with histologically proven PSC were operated on. The diagnosis was based on clinical examination, plain X-rays, ultrasonography and MRI in 5/6 patients. Also, a histological examination was done in all cases. According to the localisation of the disease, surgery was done by endoscopy alone, endoscopy together with open surgery or direct open surgery.

RESULTS

In one case each, we saw an isolated disease of the subacromial bursa or the gleno-humeral joint. In two cases, we found an intraarticular affection together with the biceps tendon sheath. The other two patients showed a massive periarticular deposition of loose bodies together with a defect of the rotator cuff. All patients with intraarticular disease (5/6) showed different stages of chondromalacia. In 5 of 6 patients all bodies could be removed at surgery. At follow-up after 36 months the patients subjectively rated the result as satisfactory to excellent. In the patients with total removal of the bodies, no recurrences were seen on plain X-ray or ultrasonography.

CONCLUSION

PSC around the shoulder appears with a variable pattern. According to the possible late complications described in the literature (i. e., secondary osteoarthritis, involvement of the rotator cuff and secondary malignant transformation), we find operative treatment justified. Surgery addressing removal of loose bodies and partial synovectomy allows good results. The operative approach (endoscopy or open surgery) is related to the localisation and severity of the condition.

The effect of limited interlaminar decompression versus complete laminectomy on intrathecal volume in degenerative lumbar spinal stenosis

INTRODUCTION

There is a controversial discussion about the adequate surgical procedure for degenerative lumbar spinal stenosis. Due to the observation that the degenerative lumbar spinal stenosis takes place predominantly at the interlaminar region on the level of the disc involving facets and bulging of the ligamentum flavum, resection of the whole lamina might not be necessary. A biomechanical study was designed to assess the effect of different decompression techniques using cadaver lumbar spine models.

METHODS

Twelve cadaver spines with CT verified degenerative lumbar spinal stenosis were dissected in order to measure the volume of the dural sac at different flexion and extension angles. Each segment (L3/4, L4/5) was decompressed first by limited interlaminar decompression and second by complete laminectomy. Intrathecal volume measurements were taken initially, after limited interlaminar decompression and after complete laminectomy.

RESULTS

Before surgical procedure, the cadaver spines showed an increase of the intrathecal volume in flexion and decrease in extension. After limited interlaminar decompression, there was a significant reduction of volume loss in extension. There was no significant additional reduction of volume loss in extension after complete laminectomy in comparison to limited interlaminar decompression.

CONCLUSION

The results allow to conclude that limited interlaminar decompression is efficient for decompression in degenerative lumbar spinal stenosis.

[Acute low back pain with progressive sensorimotor paralysis. Differential diagnosis and therapy of acute decompression disease]

HISTORY AND CLINICAL FINDINGS

A 38-year-old man presented with acute low back pain and paraesthesia in dermatome S1. 4 hours before onset of symptoms he had finished the last of three scuba dives with a maximum depth of 30 m and a total diving time of 3 hours. No alcoholic beverages were taken during or before diving. The patient was complaining of local pain in the thoracic and lumbar spine and showed a 3/5 weakness of the big toe and impaired sensitivity in the S1 dermatome. 90 minutes later the patient developed a hemiparesis of the right side including hypaesthesia and additional meningism (stiff neck).

INVESTIGATIONS

The X-rays of the thoracic and lumbar spine in two standard planes, cerebrospinal fluid examination, a cranial spiral-computer tomographie (CCT) and laboratory investigations showed no pathologic values.

DIAGNOSIS

Acute decompression sickness (DCS) type II.

TREATMENT AND COURSE

The patient received an intravenous infusion, antiinflammatory prophylaxis with dexamethasone and an immediate submission to hyperbaric oxygenation therapy. Complete recovery of neurological symptoms appeared after 4 decompression sessions in a hyperbaric chamber.

CONCLUSIONS

In patients presenting low back pain as common symptoms the differential diagnosis needs to be worked out and DCS should be included especially if progressive neurologic deficits are present. Only emergency hyperbaric oxygen therapy can compromise a sufficient therapy of these patients.

[Prevention of epidural fibrosis. Initial experiences with non-resorbable membrane]

Scars around the neural structures after opening the spinal canal are common and severe problems in spine surgery. This paper presents the use of a special membrane to avoid epidural scarring in two cases.

Sacral insufficiency fracture, an unsuspected cause of low-back pain in elderly women

Sacral insufficiency fractures (SIF) usually occur in elderly women and are secondary to various conditions, mainly postmenopausal or steroid-induced osteoporosis and radiation therapy. They are often overlooked or confused clinically and radiographically with metastatic disease. We report a case of a 72-year-old woman who presented to our department with severe low-back pain. She was thoroughly investigated for the cause of her back pain. Plain X-rays did not reveal any abnormality, but magnetic resonance (MR) scan revealed marked oedema within both sides of the sacrum, suggesting a neoplastic lesion. Bone scintigraphy did show a hyperfixation pattern forming an 'H' in the sacrum which is a characteristic sign of SIF. Computed tomography (CT) confirmed sclerotic changes interpreted as insufficiency fractures through both sacral alae. Increased awareness of these fractures may help to avoid unnecessary investigations and treatment. Bed rest and analgesia followed by rehabilitation provide good relief of symptoms.

Secondary intra-articular dislocation of a broken bioabsorbable interference screw after anterior cruciate ligament reconstruction

We report a case of intra-articular migration of the proximal part of a broken polylactic acid screw from the tibial site of anterior cruciate ligament-reconstruction with quadrupled semi-tendinosus tendon. Five months after initially successful ACL surgery the patient felt a sudden locking of the knee without another injury. MRI showed intra-articular migration of one-half of the polylactic acid screw, and standard radiographs a widening of the proximal tibial tunnel. At revision arthroscopy the broken part was easily removed. The patient had full recovery. This case demonstrates the problem of "bioscrew" breakage in ACL surgery.