Hans Jaksche

Biomechanical evaluation of vertebroplasty and kyphoplasty with polymethyl methacrylate or calcium phosphate cement under cyclic loading.

Study Design. We developed a new method to simulating in vivo dynamic loading as closely as possible, which allows comparison of kyphoplasty and vertebroplasty, as well as augmentation materials. Objective. Special interest was given to calcium phosphate cement, which might fail due to its brittleness. Summary of Background Data. Vertebroplasty and kyphoplasty are, with limitations, 2 promising alternative techniques to augment osteoporotic vertebrae with polymethyl methacrylate or calcium phosphate cements. However, little is known about the fatigue characteristics of the treated vertebrae under cyclic loading. Methods. Twenty-four intact, osteoporotic bi-segmental human specimens were divided into 4 groups: (1) vertebroplasty with polymethyl methacrylate, (2) kyphoplasty with polymethyl methacrylate, (3) kyphoplasty with calcium phosphate cement, and (4) untreated control group. After augmentation of the middle vertebrae, all specimens underwent 100,000 cycles of eccentric loading during which the specimen revolved around its longitudinal axis. Pre-loading and post-loading radiographs, and subsidence measurements at different sites of the vertebrae were taken. The overall height was additionally determined every 20,000 cycles in the material testing machine. Finally, the specimens were cryosectioned to examine the cements. Results. Loss of height progressed with strong individual differences in all groups, with an increasing number of load cycles up to median values of 2.8 mm for both augmented groups and 4.2 mm for the nonaugmented group. At the center of the upper endplate, subsidence in kyphoplasty was greater than in vertebroplasty, with little differences with respect to the kind of cement. The cryosections did not show any signs of fatigue in the polymethyl methacrylate, but small cracks were in the calcium phosphate. Conclusions. Vertebroplasty and kyphoplasty seem to be equivalent methods in strengthening osteoporotic vertebrae. However, these results cannot be transferred to the treatment of fractures with these methods. A “physiologic” loading situation was achieved by complex motion, including all combinations of flexion/extension with lateral bending during eccentric cyclic loading.

Interdisciplinary approach to balloon kyphoplasty in the treatment of osteoporotic vertebral compression fractures

Osteoporotic vertebral compression fractures (VCFs) are associated with a series of clinical consequences leading to increased morbidity and even mortality. Early diagnosis and therapeutic intervention is desirable in order to remobilise patients and prevent further bone loss. Not all fractures are, however, sufficiently treatable by conservative measures. Here, vertebroplasty and kyphoplasty may provide immediate pain relief by minimally invasive fracture stabilisation. In cases of acute fractures, kyphoplasty has the potential to reduce kyphosis and restore the normal sagittal alignment of the spine. The complex nature of systemic osteoporosis, coupled with the intricate biomechanics of vertebral fractures, leads to a clinical setting which is ideally treated interdisciplinarily by the rheumatologist and spine surgeon.

Predictors of outcome in head injury: proposal of a new scaling system.

BACKGROUND In a statistical outcome analysis covering 10 years, 554 patients with isolated head trauma were analyzed. The aim of this study was to combine clinical and computed tomographic characteristics in a prognostic scoring system determining outcome after head injury. METHODS After collection of data, mortality and morbidity were determined for each clinical and radiologic parameter; a different grading from 1 to 8 points was then attached to each parameter. The total score for each patient was calculated by adding the individual points from the different parameters. RESULTS Significant differences in outcome (p < 0.01, Mann-Whitney U test) were registered in steps from 0 to 10 points (group I), 11 to 20 points (group II), and > 20 points (group III). Group I had a mortality of 8.3%, and patients in groups II and III died in 51.2% and 80.8%, respectively. Patients in group I had a Glasgow Outcome Scale (GOS) score of 4 and 5 in 19.4% and 56.7%, respectively, whereas group II reached a GOS score of 4 or 5 in only 9.9% and 1.7%, respectively. Patients in group III never reached a GOS score of 4 or 5. CONCLUSION The presented scaling system allows a predictive value in mortality and morbidity to be determined for each patient suffering from brain trauma.

Reduction in late postoperative pain after iliac crest bonegraft harvesting for cervical fusion: a controlled double-blinded study of 100 patients

SummaryBackground. A randomized prospective double-blinded study was conducted in 100 patients suffering from mono- or bisegmental cervical retrospondylosis or disc herniation.Method. In group I, 50 patients were treated by injection of 10 ml Ropivacaine 7,5% at the iliac crest bonegraft donorsite. Local anaesthetic (LA) was injected through the wound drainage after closure of the muscle fascia, the suction drainage was opened after closure of the skin. Group II was treated with 0,9% saline. Operator and patient were blinded to the injected substance. Daily controls of pain intensity were made with the 10 cm visual analog scale from 0 (no pain) to 10 (severe pain) for 5 days. All patients were questioned regarding pain character and movement provoking pain. Additional pain medication was standarized.Findings. Statistical analysis of mean pain intensity over the whole hospital stay showed a significant difference in pain intensity between the two groups (p = 0,017, Chi-Square test). The comparison between pain intensity with LA and without LA showed a gradual increase in statistical significance from day 1 to day 5 (day 1: p = 0,54, not significant; day 2: p = 0,026; day 3: p = 0,008; day 4: p = 0,004; day 5: p = 0,002).Interpretation. This data shows that intra-operative blockage of peripheral nociceptive structures results in decreased pain at later time points. We conclude that wound infiltration with 7,5% Ropivacaine after bonegraft removal at the iliac crest is effective in reducing postoperative pain.

Minimally Invasive Vertebral Augmentation Techniques in Osteoporotic Fractures

Minimally invasive vertebral augmentation techniques fill the gap between conservative treatment and open surgical fusion in the treatment of osteoporotic vertebral fractures. Both vertebroplasty (VP) and kyphoplasty (KP) have proven to be effective in the reinforcement of a fractured vertebral body and provide pain relief, but both procedures have technical differences. Furthermore, patient selection criteria are still under debate, as no randomized comparison trials of VP and KP exist. A competitive environment has arisen between both methods. In the authors’ opinion, VP and KP do not replace, but complement each other and offer both potential benefits. It is the purpose of this article to outline the different kinds of application of both methods.

Complex 360°-reconstruction and stabilization of the cervical spine due to osteomyelitis

Osteomyelitis of the cervical spine may lead to profound bony destruction. The presented case developed multilevel osteomyelitic destruction of the cervical spine after decompression due to cervical myelopathy. He could be cured by a multiple-stage procedure: step one: debridement and removal of all anterior implants with vacuum-assisted closure combined with dorsal instrumentation from C0 to T3; step two: anterior reconstruction with expandable titanium cages and plate. The patient regained walking with the aid of a walking frame. The following recommendations are given: multiple stage procedure, extensive debridement and stabilization via an anterior and posterior approach, use of titanium implants.

Intraoperative urodynamics in spinal cord surgery: a study of feasibility

Abstract.Intraoperative monitoring (IOM) of bladder function in spinal cord surgery is a challenging task due to vegetative influences, multilevel innervation and numerous supraspinal modulating factors. Despite routine use of urodynamics in neurosurgery for implantation of bladder stimulators or denervation of nerve fibres in spastic reflex bladders, application of IOM in patients with spinal cord tumours or tethered-cord syndrome is not widespread. Combining urodynamics with sphincter electromyography (EMG) in IOM enables identification of bladder efferents responsible for contraction and continence. We monitored four patients with ependymoma of the Cauda equina, one patient with tethered-cord syndrome and two patients with cervical intramedullary tumours. In all patients undergoing operations of the Cauda equina, identification of bladder efferents responsible for detrusor contraction was possible. There was good correlation between preoperative bladder dysfunction, preoperative urodynamics and intraoperative pressure increase by bladder contraction or latency between stimulation and contraction. This method proved unsuitable for intramedullary tumours where no contraction of the bladder could be observed while stimulating the spinal cord. Intraoperative monitoring of urodynamics is an effective tool for identifying bladder efferents in the Cauda equina. Intraoperative conclusions on bladder dysfunction through registration of pressure increase and latency are possible.

Risiken der Vertebro- und Kyphoplastie

ZuammenfassungVertebro- und Kyphoplastie haben sich als effektive minimalinvasive Verfahren zur Behandlung osteoporotischer Wirbelkörperfrakturen erwiesen. Unter Beachtung einiger Vorsichtsmaßnahmen sind die Risiken überschaubar. Die vorliegende Arbeit gibt einen Überblick über das Risikopotenzial beider Verfahren und zeigt Maßnahmen zur Fehlervermeidung auf.AbstractVertebroplasty and kyphoplastie have proved to be effective minimally invasive methods in the treatment of osteoporotic vertebral fractures. If adequate precautions are taken the risks involved can be foreseen. This article gives a summary of potential risks and describes how complications can be avoided.

Results in kyphoplasty, risks and complications

During recent years kyphoplasty has gained increasing importance in the treatment of osteoporotic vertebral body fractures. In addition to the pain-relieving effect, the possibility of reducing the fracture and thus preserving the spinal alignment is advantageous. Patients with these fractures often suffer from chronic pain, as well as the acute pain, because of the increasing kyphotic condition of the vertebral body and the resulting deviation of the spine. The change in spinal alignment correlates with restricted mobility and loss of quality of life, leading to the increased mortality rate following vertebral body fractures [Lyles 1993]. Furthermore, these parameters get progressively worse, with an increasing number of vertebrae affected and the resulting increase of the positional failure [Ross 1997]. It would be invaluable for those affected if this development could not only be stopped but even reversed with minimally invasive technology causing little stress to the patients.

Die Behandlung des Hirnabszesses

ZusammenfassungIn den Jahren 1999–2001 wurden 11 Patienten mit Hirnabszessen zuerst operativ, anschließend mit hyperbarer Oxygenierung (HBO) behandelt: 8 Männer und 3 Frauen im Alter von 16–89 Jahre.Davon waren 4 Fälle per continuitatem,5 hämatogen und 2 iatrogen entstanden.Bei allen Patienten wurden neuronavigations- und ultraschallunterstützt offene Kraniotomien oder Bohrlochkraniotomien durchgeführt. In 8 Fällen konnten Anaerobier isoliert werden, bei 1 Patient Aspergillus, zusätzlich traten 2 iatrogene Infekte mit Staph. aureus auf.Alle Patienten wurden mit mindestens 10 Behandlungssitzungen HBO (2,4 Bar über 140 min) behandelt.Bei einem 46-jährigen Patienten bestand neben der Abszesshöhle eine klinisch inapparente Infarzierung, die weitere Verlaufskontrolle zeigte eine komplette Regression des Infarktes. Ein Patient verstarb.Im weiteren Follow-up von 8 Monaten traten keine Abszessrezidive auf.Die HBO-Therapie stellt somit eine sinnvolle Ergänzung der Behandlung von Hirnabszessen dar, insbesondere beim Vorliegen anaerober Keime.Eine endgültige Beurteilung dieses Vorgehens kann jedoch erst nach Erfahrungen mit einem größeren Patientenkollektiv erfolgen.AbstractFrom 1999–2001,11 patients with brain abscess were treated neurosurgically and with hyperbaric oxygenation (HBO): 8 men, 3 women in the age of 16–89 years.The pathogenesis was per continuitatem in 4 cases,haematogenous spread in 5 cases, postoperative in 2 cases.All patients underwent neuronavigation or ultrasound guided surgical intervention.Anaerobic pathogens were insolated in 8 patients,Aspergillus in 1 case,2 postoperative infections with Staph. aureus were registered.All patients underwent at least 10 treatment sessions of HBO (2,4 bar for 140 min.) One clinically inapparent infarction close to the abscess cavity was seen in routine CCT, the follow up CCT showed a complete regression of the infarct. One patient died.There was no abscess recurrence in follow up of 8 months.HBO-therapy provides the neurosurgeon with an additional tool in treating brain abscess caused by anaeobic pathogens.However, final conclusions regarding clinical outcome can only be drawn after clinical experience with a larger patient collective.