Rainer Abel

Induction of Intervertebral Disc–Like Cells From Adult Mesenchymal Stem Cells

The potential of adult mesenchymal stem cells (MSCs) to differentiate towards cartilage, bone, adipose tissue, or muscle is well established. However, the capacity of MSCs to differentiate towards intervertebral disc (IVD)‐like cells is unknown. The aim of this study was to compare the molecular phenotype of human IVD cells and articular chondrocytes and to analyze whether mesenchymal stem cells can differentiate towards both cell types after transforming growth factor β (TGFβ)‐mediated induction in vitro.

Repeated botulinum-A toxin injections in the treatment of myelodysplastic children and patients with spinal cord injuries with neurogenic bladder dysfunction

Authors from Germany describe the use of botulinum toxin in the treatment of myelodysplastic children and found it to be safe and effective. They found that repeat treatments are as effective as the first one, with no evidence of tachyphylaxis, antibody formation or detrusor fibrosis.

Residual deformity of the spinal canal in patients with traumatic paraplegia and secondary changes of the spinal cord

Introduction: The effect of spinal deformity with posttraumatic kyphosis and stenosis of the spinal canal in producing secondary changes of the spinal cord has been discussed for quite some time. Since the advent of magnetic resonance imaging (MRI), 20–40% of patients with posttraumatic paraplegia are found to develop hydromyelia. Purpose of our study: To evaluate the influence of residual spinal deformity, defined by the extent of the posttraumatic kyphosis and stenosis, in the development of posttraumatic hydromyelia. Material and methods: Two hundred and seven cases of traumatic paraplegia with MRI follow-up were reviewed retrospectively. A minimum of 3 years duration between trauma and MRI study was required (mean 10.6 years [3.2–38.3]). For statistical analysis two groups of patients were formed: with hydromyelia and without hydromyelia. After healing of the fracture, the extent of the kyphosis and stenosis, as well as the characteristics of the paraplegia were noted. Results: We found that 53 patients had hydromyelia. A highly significant correlation was found for the extent of spinal stenosis and the amount of kyphosis. Cluster analysis indicated that patients with more than 15 degrees of posttraumatic kyphosis and more than 25% of stenosis were twice as likely to develop hydromyelia. The level of the lesion and the remaining neurological function was not proven to have any influence towards the development of hydromyelia. Conclusions: These results support the idea that chronic mechanical stress to the spinal cord increases the risk for the development of hydromyelia. Surgical reconstruction should be considered for all patients to prevent secondary changes of the spinal cord.

Resection of heterotopic ossification of the hip in spinal cord injured patients.

Twenty nine spinal cord injury patients were treated by resection of heterotopic ossification in 41 hips. The average follow-up period after surgery was 4.2 years. The mean time to surgery after injury was 82.1 months. The indications for surgery were seating problems, loss of function, pressure sores and pain. The average preoperative motion in flexion and extension was 21.95°, the average intraoperative motion was 94.51°. The average motion at follow-up evaluation was 82.68°. Clinical relevant recurrence occurred in three patients. Complications excluding recurrence occurred in 10 hips, including deep and superficial wound infections, fracture, aneurysm and pressure ulcer. The operation was followed by a specific regime of physiotherapy and radiation therapy.

Kyphectomy in children with myelodysplasia : Results 1994-2004

Study Design. We retrospectively studied 24 consecutive pediatric patients with lumbar kyphosis due to myelodysplasia who had received corrective surgical treatment with the Warner and Fackler technique from 1994 to 2004. Objectives. The purpose of the study was to evaluate the technical problems and outcome and to identify complications of this treatment modality, especially regarding the biomechanics. Summary of Background Data. The management of lumbar kyphosis (8%–20%) in conjunction with myelodysplasia is difficult. In 1993, Warner and Fackler presented an elegant surgical technique, which was used here. Methods. Corrective surgery was performed in 24 patients with an average preoperative lumbar kyphosis of 124°. The correction was achieved by kyphectomy combined with stabilization using rods and wires as described by Warner and Fackler. Outcome was rated and complications were identified using data from the clinical records. For biomechanical analysis of the surgical construct, a force model was developed. Results. The mean extent of lumbar kyphosis could be corrected from 124° before surgery to 43° after surgery. Biomechanical analysis showed that inadequate correction results in implant failure. Conclusion. Surgery should always be performed with the intention to reestablish the sagittal profile inasfar as possible so as to reduce the risk of implant failure.

Gait analysis on the treadmill: monitoring exercise in the treatment of paraplegia

Study design: A prospective study was performed to evaluate the gait training of seven consecutive spinal cord injured patients and 10 controls on a treadmill using instrumented gait analysis and video documentation.Objectives: To determine whether it is possible to maintain gait motion within physiological limits during treadmill training.Setting: Primary and secondary care unit for spinal cord injury, Heidelberg, Germany.Methods: Treadmill training was instituted as early as possible. Gait analysis was performed when the patients were stable enough to walk without manual aid from therapists and enough endurance to allow measurements. A control group of healthy volunteers were examined as well. Video documentation and a camera system using passive markers were employed.Results: Treadmill training started with weight reduction of 25% of bodyweight (18 (0–35) kg), maximum walking speed 0.28 (0.15–0.7) m/s and maximum walking duration 4.7 (3–7) min. At the end of the training, weight reduction decreased to 9.3 (0–20) kg, maximum walking speed increased to 0.67 (0.23–1.1) ms with a maximum walking duration of 11 (8–15) min. 3-D motion analysis of hip, knee and ankle demonstrated joint excursions almost entirely within the limits of normal gait. Exceptions were due to fixed contractures.Conclusions: Our data suggests that it is possible to perform early gait training on a treadmill with no supportive orthoses within the physiologic range of joint motion. The risk for repetitive stress injuries or other negative effects is low.

Management of Orthopaedic Sequelae of Congenital Spinal Disorders

Introduction Myelomeningocele (myelodysplasia or spina bifida) refers to a wide range of neural tube defects affecting the spine and spinal cord. These defects result from maldevelopment of the neuropore and the adjacent mesodermal and ectodermal structures during embryogenesis. Myelomeningocele can be classified as either open or closed according to the presence or absence of exposed neural tissue. Myelomeningocele occurs early during embryogenesis, resulting in a certain number of fetuses being spontaneously aborted. In addition, advances in prenatal screening have led to an increase in the number of therapeutic abortions. Because of the unknown numbers of spontaneous and therapeutic abortions, establishing the true incidence of myelomeningocele is very difficult. Epidemiological studies have revealed that the prevalence of myelomeningocele varies, depending on such factors as ethnicity, race, geography, and temporal trends. It is estimated that over 4500 pregnancies per year are affected by this malformation in the European Union, and approximately 3000 pregnancies per year are affected in the United States. In 2005, the rate of myelomeningocele was 18.0 per 100,000 births in the United States. Over the last three to four decades, there has been an overall decline in the prevalence of myelomeningocele in most industrialized countries. This is in part due to advances in the refined resolution of ultrasonography, the introduction of serum alpha-fetoprotein measurements as a diagnostic modality, elective termination of affected pregnancies, and folic acid supplementation. The identification of environmental risk factors, including diabetes mellitus, obesity, smoking, gene polymorphisms, and certain medications, has also contributed to this considerable decline. The orthopaedic surgeon plays an important role in the multidisciplinary team involved in the care of children with congenital spinal disorders such as myelomeningocele. Myelomeningocele is a complex deformity that can lead to multiple musculoskeletal problems, such as clubfoot, paralytic pes calcaneus, spinal deformities, hip dislocations, fractures, and pressure ulcers. Prior to the 1950s, these problems in patients with myelomeningocele were rare because most patients died before the age of two years. With advances in medical management, the life expectancy and quality of life for these patients have increased dramatically. This paper outlines our more than twenty-year experience in treating the musculoskeletal sequelae of congenital spinal disorders in children.

Use of the ring fixator in the treatment of fractures of the lower extremity in long-term paraplegic and tetraplegic patients

Study design: Retrospective study.Objectives: To examine the value of operative fracture stabilization by means of the ring fixator in fractures of the lower extremity in the presence of chronic paralysis caused by transverse lesions of the spinal cord.Setting: A specialist center for the treatment of spinal cord injuries in Germany.Methods: Clinical examination of the lower extremities with side-for-side comparison, radiological investigation of the fractures, patient survey.Patients: In 21 patients with chronic spinal cord lesions, 22 fractures of the lower extremities were treated with the ring fixator.Results: At follow-up a mean of 41.5 months after fracture healing it could be shown that movement in the knee and ankle joints on the same side as the fracture was not restricted by more than 10° in any of our patients. No losses affecting activities of daily living were reported, and 19 of the 21 patients were satisfied with the result achieved with this technique. After four of the 22 operations there were complications. Malalignments were visible radiologically following five of the fractures.Conclusions: In osteoporosis-induced fractures of the lower extremities in chronically paraplegic and tetraplegic patients, fracture stabilization with the ring fixator, with fewer complications and better results in terms of joint mobility, is superior to the conservative treatment so far given preference in the literature. It should be offered as an alternative to conservative treatment in the case of pathological fractures.

Posterior decompression and stabilization for metastatic compression of the thoracic spinal cord: is this procedure still state of the art?

Study Design:Retrospective study utilizing the standard patient data documentation of a spinal cord injury (SCI) unit.Objective:To examine the efficacy and outcome of posterior decompression and stabilization for metastatic cord compression.Setting:Orthopedic university hospital with large SCI unit.Methods:The 34 consecutive patients who had presented with symptoms of spinal cord compression due to metastatic disease and progressive neurologic deficit were treated using a uniform surgical approach (posterior decompression and stabilization). After surgery, all treatment options available in a full-featured SCI unit were applied as necessary and suitable. Outcome was rated concerning neurologic function (American Spinal Injury Association, ASIA), functional status (Functional Independence Measure) and pain. The results were compared to the published results, focusing on publications describing results of anterior surgical approaches to the spine.Results:Evaluation of the results of the ASIA exams showed that progression of the neurologic deficit could be stopped in the majority of cases—however recovery of neurologic function was rare. The functional status could be improved markedly and good pain reduction was achieved.Conclusion:Immediate surgery can be recommended if the general condition of the patient warrants surgical intervention. Using accepted standards of documentation for SCI, a clear perspective of the results that can be expected is provided. Comparing the results of this study with the current literature there is no evidence that anterior approaches are superior.

Paraplegia in cases of septic diseases of the spine

BACKGROUND Paraplegia of non-traumatic origin has an increasing incidence. Infection of the spine is a major contributor to the number of these cases. Besides adequate management of spinal cord injury, the treatment of these patients requires specific therapeutic techniques. PATIENTS AND METHODS Eighteen patients with acute pyogenic infection of the spine and spinal cord injury were admitted to our facility in the years 1997-2000. All except two patients were treated by surgical debridement and internal stabilisation. RESULTS The infections healed after surgical treatment in all cases. Neurological function improved and no patient showed neurological deterioration. Both patients who were not fit for surgery died during treatment. CONCLUSION Surgical instrumentation and replacement of the destroyed vertebra, despite a pyogenic environment, resulted in permanent resolution of the infection. There is potential for neurological recovery but full recovery is rare.