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Biomedical subjects

W Caspar

Publications and source records attributed to W Caspar.

At least 19 recordsLinked to original sources
PubMed2000

[Initial stability of two PLIF-techniques. A biomechanical comparison using a finite element model].

The purpose of this study was to compare the initial stiffness of two techniques for posterior interbody lumbar fusion (PLIF) by a finite element approach. Thus a finite element model of a human L3/4 spinal segment was generated. Stiffness of the intact model was tested under compression (600 N), torsion (25 Nm) and shearing forces (250 N) without preload. The results were compared to the stiffness following simulation of PLIF with two BAK-Cages and PLIF with two Harms-Cages and additional posterior screw-rod-osteosynthesis. PLIF with two BAK-Cages resulted in a loss of stiffness in compression, torsion and shearing. PLIF with two Harms-Cages and posterior osteosynthesis resulted in an increase of stiffness in compression, torsion and shearing.

Biomechanical Phenomena↗
PubMed1999

Evaluation of a new monocortical screw for anterior cervical fusion and plating by a combined biomechanical and clinical study.

The purpose of this combined study was to evaluate the stability and safety of a new monocortical screw-plate system for anterior cervical fusion and plating (ACFP) according to Caspar in comparison with classical bicortical fixation. In the biomechanical part of the study two groups, each comprising six fresh human cadaveric spines (C4-C7), matched for bone mineral density, additionally resulting in almost the same mean age, were used. Range of motion and neutral zone were analyzed in flexion-extension, rotation (left, right) and lateral bending (left, right) using pure moments of +/- 2.5 Nm for each specimen in the intact state, after discectomy at C5/6 and after discectomy at C 5/6 followed by bone grafting plus plating (Caspar plates), with either monocortical or bicortical screws. For all three motion planes, no significant difference could be found between the new monocortical and the bicortical fixation techniques. The clinical part of the study was performed as a prospective study on 30 patients suffering from symptomatic degenerative cervical disc disease in one segment. At the latest follow-up, no hardware- or graft-related complications were seen in any of the patients. Following these findings monocortical screw fixation can be recommended for the majority of anterior cervical fusion and plating procedures in degenerative disease, making the procedure quicker, easier, and safer. Bicortical screw fixation still has specific indications for multilevel stabilization, poor bone quality (osteoporosis, rheumatoid disease - as bicortical oversized rescue screw), unstable spines (trauma, tumour) and in particular for the realignment of kyphotic deformities (restoration of the normal lordotic curve). Due to the design of the study the results apply only to surgical treatment of monosegmental degenerative disc disease at the time.

Adult↗
PubMed1999

Anterior cervical fusion and trapezoidal plate stabilization for re-do surgery.

BACKGROUND: Pseudarthrosis, graft fracture or dislocation, and kyphotic angulations are highly undesired complications after surgery of the cervical spine. The purpose of this retrospective study was to evaluate the effect of anterior cervical fusion and plating in cases of failed cervical spine surgery. METHODS: From January 1980 to December 1993 41 patients (25 male, 16 female, mean age 46.8 years, range 30-66 years) underwent corrective surgery of the cervical spine in our department. A total of 33 patients had one, 7 patients had two, and one patient had three previous cervical operations. Re-do surgery was most frequently indicated because of intractable head-neck-shoulder-arm-pain corresponding with radiological findings. Corrective surgery consisted of anterior cervical decompression, realignment, autologous iliac crest bone graft fusion, and trapezoidal plate stabilization. Clinical and radiological follow-up examinations were performed, ranging from 20 to 112 months with a mean of 24.7 months, in 37 patients. Epidemiological, clinical, and radiological data were collected and used for this retrospective study. RESULTS: Of 37 patients 21 showed complete alleviation of head-neck-shoulder pain, 10 improved, and six remained unchanged. Of 15 myelopathy patients, one showed further progress, two were unchanged, four were normal, and eight showed only mild signs of medullary irritation, e.g., hyperreflexia or minimal spasticity. Radiological examinations showed a stable bony fusion in optimal alignment in all 37 patients. CONCLUSION: Based on these findings, anterior cervical decompression, fusion, and plating is a rational treatment in cases of failed cervical fusion.

Adult↗
PubMed1999

Anterior cervical plating for the treatment of neoplasms in the cervical vertebrae.

OBJECT: To assess clinical outcome and survival in patients with cervical vertebral spinal neoplasms after they have undergone anterior decompression and cervical plate stabilization (ACPS) by using either autologous bone graft or polymethylmethacrylate (PMMA) as the anterior load-bearing support structure. METHODS: This was a retrospective case study composed of 30 patients harboring cervical spinal vertebral neoplasms who underwent anterior cervical decompression and (ACPS) within a 7-year period. Postoperative immobilization included treatment in a halo brace in two cases and in a hard cervical collar for the remaining patients. Postoperatively most patients underwent radio- and/or chemotherapy. All patients except one benefited from a significantly improved quality of life with decreased pain and/or improved neurological status. The mean Kaplan-Meier survivoral estimate was 35.8 months (range 8 days-11.3 years, with 10 patients alive at most recent follow-up contact). Patients achieved long-term or lifelong mechanical stability in the cervical spine, and only one patient required a repeated posterior stabilization procedure. No hardware-related complications occurred. One patient died 8 days postoperatively of pneumonia. A nonsignificant difference in survival (p = 0.2164) was observed between patients harboring metastatic neoplasms (26.8 months) and those harboring lymphomatous and multiple myeloma neoplasms (54 months). CONCLUSIONS: Favorable clinical outcome of both neurological symptoms and pain can be achieved using ACPS after surgery for neoplasms in the cervical vertebrae. Furthermore, long-term or lifelong cervical spine mechanical stability with bone fusion is achieved using this technique even when radiation therapy is delivered to the site of the bone graft.

Adult↗
PubMed1999

[Primary stability of 2 PLIF (posterior lumbar interbody fusion) techniques--a biomechanical and finite element analysis].

The purpose of this study was to compare the initial stiffness of two techniques for posterior interbody lumbar fusion by biomechanical and finite element analysis. Initial stiffness was tested under compression, torsion and shearing forces. The effect of an increasing initial stability by additional posterior instrumentation is proven by the biomechanical analysis and the finite element method.

Biomechanical Phenomena↗
PubMed1998

Reoperation in patients after anterior cervical plate stabilization in degenerative disease.

STUDY DESIGN: Consecutive case retrospective chart review. OBJECTIVES: First, to assess whether the number of' patients requiring a second cervical surgical intervention was changed as a result of using anterior cervical plate stabilization, and second, to determine the additional risks and/or benefits associated with the hardware implantation. SUMMARY OF BACKGROUND DATA: The optimal technique of performing stabilization, arthrodesis, and alignment of a cervical segment after discectomy with neural decompression in degenerative disease has yet to be determined. METHODS: The charts of 402 patients who had undergone an anterior cervical discectomy and arthrodesis for degenerative disease performed both with and without anterior cervical plate stabilization were reviewed, and reoperation data were compiled. The average follow-up time was 3.8 years (range, 1.5-9.4 years). RESULTS: Of 365 patients with 1- or 2-level cervical arthrodesis, 22 required a second surgical intervention (20 bone alone, 2 with anterior cervical plate stabilization). The Log-Rank test, which uses all patients and their total follow-up periods, was statistically significant favoring anterior cervical plate stabilization at one and two levels (P = 0.015). CONCLUSIONS: The addition of anterior cervical plate stabilization in one- and two-level cervical degenerative disease supplements the internal stabilization initially provided by the bone graft, and yields a lower reoperation rate.

Adult↗
PubMed1998

Anterior cervical plate stabilization in one- and two-level degenerative disease: overtreatment or benefit?

This consecutive case retrospective chart review of 356 patients compares the reoperation rate of one- and two-level anterior cervical discectomies for degenerative disease with and without anterior cervical plate stabilization (ACPS). A total of 210 patients underwent surgery without ACPS (bone alone) and 146 patients underwent surgery with the addition of ACPS. Follow-up ranged from 1 to 9 years. A total of 22 patients with one- or two-level cervical arthrodesis required a second surgical intervention (19 bone alone, 3 with ACPS). Reoperations were performed in the bone-alone group for pseudarthrosis in 12 cases and for progression of degenerative disease in 7 cases. The reoperations in the ACPS group were performed for pseudarthrosis in one case and settling of the graft with screw fracture before fusion in two cases. The log-rank test, which uses all patients and their total follow-up periods, was statistically significant in favoring ACPS (p = 0.05). Furthermore, the reoperation rate after 1 year was also significantly lower when ACPS was utilized compared with bone alone (p = 0.0308, Fisher's exact test, two tailed). These data provide evidence that the addition of ACPS in one- and two-level cervical degenerative disease does not constitute overtreatment but rather supplements the internal stabilization initially provided by the bone graft and yields a lower reoperation rate.

Adult↗
PubMed1994

Precise and limited decompression for lumbar spinal stenosis.

Fifty-eight consecutive patients with lumbosacral nerve root entrapment due to spinal stenosis were treated with modified microsurgical decompression. Only the clinically relevant sides and levels were decompressed while the spinous processes, the interspinous ligaments, the medial portion of ligamentum flavum and the functionally important parts of the facet joints were preserved. The reviewers rated recovery as good or excellent in 71% of patients while patient self-assessment indicated 76% good or excellent outcome. These data suggest that microsurgical decompression of spondyloarthritic changes can effectively relieve the signs and symptoms of nerve root compression and that with careful evaluation of all available data the number of nerve roots requiring decompression is often fewer than what is suggested by diagnostic images alone.

Adult↗
PubMed1994

[Dens fracture in elderly patients and surgical management].

The problems of surgical therapy in seven patients aged over 70 years are discussed. Clinical and radiological findings as well as operative treatment (anterior transaxial screw osteosynthesis or posterior atlanto-axial arthrodesis) are analysed in detail. Five out of 7 patients treated in this way could be early mobilised. Two patients died on multiorgan failure after an initial uneventful postoperative course (28.6% mortality rate). A stable osteosynthesis was obtained in all cases; a complete bony fusion as could be radiologically demonstrated, occurred in four out of the five survivors. We feel that despite this relatively high mortality rate surgical treatment provides better recovery chances and a higher quality of life to such patients.

Aged↗
PubMed1991

Lumbar percutaneous discectomy. Initial experience in 28 cases.

Since November 1988, 28 patients with lumbar L5 radiculopathy refractory to conservative care and with a radiologically verified central or mediolateral disc herniation at the level of L4/L5 had had a percutaneous discectomy. Radiological verification consisted of spinal CT +/- myelography, +/- myelo-CT, +/- MRI. A short-term follow-up analysis of at least 2 months taking the clinical and functional status as well as the professional reintegration into account revealed a 64.3% (18/28 patients) satisfactory outcome and a 32.1% (10/28 patients) failure rate. Of the latter 28.6% (8/28 patients) required further open surgery. One patient whose pain had only partially in regressed was shown at open operation to have a sequestered cranial prolapse as revealed by spinal CT after the percutaneous procedure. There were no major complications. One patient developed a sequestered extraforaminal herniation through the nucleotomy canal three weeks after the procedure. One patient bled for 2 minutes. There were no major vessel injuries. One patient reported local muscular pain, and enhanced nerve root pain after introduction of the trocar sleeve.

Adult↗
PubMed1991

The Caspar microsurgical discectomy and comparison with a conventional standard lumbar disc procedure.

The outcome in 119 patients who were operated on with a conventional standard lumbar discectomy procedure was retrospectively compared with that in 299 patients who were operated on with a microsurgical discectomy technique developed in Homburg/Saar, Federal Republic of Germany by the senior author (W.C.). All patients in this consecutive series had "virgin" lumbar radiculopathy evaluated and operated upon by two experienced surgeons at one institution. Determination of the final outcome was made objectively by an impartial third party using identical criteria for both groups, and with a patient self-evaluation form. The study looked at various pertinent aspects of the treatment course and at final outcome. The results in the microsurgical group were significantly favorable: fewer levels were explored: there was less operative blood loss and a decreased incidence of deep venous thrombosis, urinary tract infections, pulmonary emboli, and bladder catheterization; the time to full ambulation, discharge, and return to work was faster: and there was a decrease in change of occupation and a greater percentage of satisfactory final outcomes, as measured both objectively and subjectively. A description of the microsurgical technique used in this study, which differs significantly from existing microdisectomy techniques, is presented. The authors conclude that the microsurgical disectomy technique presented in this study is a safe and effective approach to the treatment of lumbar radiculopathy.

Adolescent↗
PubMed1990

Acute spinal intradural extramedullary hematoma: a nonsurgical approach for spinal cord decompression.

The authors present the case of a 60-year old man with a spontaneous spinal intradural hematoma in the thoracic and lumbar region, which was caused by anticoagulant therapy and led to a severe progressive transverse lesion. After substitution of coagulation factors, a small catheter was inserted into the subarachnoid space via a lumbar puncture. By alternating irrigation and suction removal of the blood clot, restoration of the cerebrospinal fluid passage was possible along with a marked improvement in the neurological deficits. At 8 months' follow-up, the patient had completely recovered from the severe paraparesis and bladder dysfunction.

Catheterization↗
PubMed1989

Anterior cervical fusion and Caspar plate stabilization for cervical trauma.

A technique for anterior cervical iliac graft fusion with standardized, commercially available screw and plate fixation (Caspar plating) has been developed. The step-by-step procedure, as well as the instruments designed to facilitate the procedure, are described in this report. Sixty cases of cervical trauma (fractures, subluxations, ligamentous instability, or a combination of these problems) were treated with Caspar plating. All patients obtained fusion, and stability was achieved immediately after surgery without external stabilization. No unusual surgical complications occurred, and the most dreaded complication of dural penetration by drilling or screw placement was not observed. This report details the neurological presentation, anatomical lesions, surgical therapy, and outcome of these patients. Caspar plating combines the advantage of an anterior surgical approach with immediate postoperative stabilization without external stabilization. This advantage persists even in the presence of posterior ligamentous instability. The technique is an important addition to the surgical treatment of cervical trauma.

Adolescent↗
PubMed1978

[A microsurgery operation for lumbar disc herniation (author's transl)].

An application of operating microscope for lumbar disc herniation surgery may reduce surgical trauma as compared to non-microsurgical procedure. This can be done very easily by monosegmental approach and employing of the improved optical conditions. This procedure implies better differentiation of anatomical structures and therefore also gentler manipulation of nerve root and dural sac. This procedure can be led to (1) much less bleeding, (2) much less (little) damage of muscle and nerve, (3) less local complication due to postoperative muscular insufficiency, (4) short period of the hospitalization and (5) easiler having postoperative rehabilitation.

Adult↗