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M de Kleuver

Publications and source records attributed to M de Kleuver.

At least 19 recordsLinked to original sources
PubMed2005

A concise follow-up of a previous report: posterior reduction and anterior lumbar interbody fusion in symptomatic low-grade adult isthmic spondylolisthesis.

We report the updated results for a previously evaluated surgical treatment for adult low-grade isthmic spondylolisthesis. In 12 patients a decompressive laminectomy was performed followed by a circumferential fusion using posterior pedicle screw instrumented reduction and staged anterior cage-assisted interbody fusion. Average time to follow-up was 5.6 (range 4.9-6.6) years. The average Oswestry Disability Index at last follow-up was 14 compared to 13 at 2.1-year follow-up. The average VAS score for back pain at last follow-up was 2.3 compared to 2.8 at 2.1-year follow-up. Ten patients had resumed their pre-symptom work status. This study demonstrates maintenance of the good clinical and radiological 2.1-year outcome after 5.6-year follow-up with no deterioration of back-pain scores.

Adult↗
PubMed2005

Triple osteotomy of the pelvis for acetabular dysplasia: results at a mean follow-up of 15 years.

We report the long-term results of 51 pelvic osteotomies in 43 patients with a mean follow-up of 15 years (13 to 20). The mean age of the patients was 28 years (14 to 46). At review three patients were lost to follow-up, and six had received a total hip arthroplasty. Of 48 hips, 42 (88%) were preserved, with good to excellent clinical results in 27 (64%). Pre-operatively, 41 (80%) of the treated hips had shown no sign of osteoarthritis. Thirty-one (65%) hips showed no progression of osteoarthritis after follow-up for 15 years. Significant negative factors for good long-term results were the presence of osteoarthritic changes and a fair or poor clinical score pre-operatively. Pelvic reorientation osteotomy for symptomatic hip dysplasia can give satisfactory and reproducible long-term clinical results.

Acetabulum↗
PubMed2004

Influence of electrode impedance on threshold voltage for transcranial electrical stimulation in motor evoked potential monitoring.

Motor potentials evoked by transcranial electrical stimulation (TES) are used for monitoring the motor pathways, with emphasis on the spinal cord and brainstem. The stimulus voltage threshold is the voltage below which no motor response can be elicited. It has frequently been used as a monitoring parameter. However, its value can be limited, because it is affected by the impedance of the stimulus electrode. For example, the voltage threshold can change owing to formation of oedema of the scalp. The relationship between the TES voltage threshold and the electrode impedance of different electrode types was studied and discussed in the context of neuromonitoring: 323 impedance and voltage threshold pairs were studied, and TES was performed with disc cup EEG electrodes (six), corkscrew electrodes (type I: seven, type II: eight), multiple EEG needle electrodes (16) and a large needle electrode Cz' (anode) together with a ground strip over the forehead (cathode) (286). The study found the voltage threshold to be strongly dependent on electrode impedance when the impedance was higher than 460 omega (correlation: R2=0.87; p < 0.001). Below 460 omega, which included 91% of the category with the largest electrode surfaces, 25% of the multiple EEG electrodes and 75% of type II corkscrew electrodes, no significant correlation (R2=0.0064; p=0.15) was found. It was concluded that the correlation between the TES voltage threshold and electrode impedance can be markedly reduced by using TES electrodes with large contact surfaces, resulting in limit values for these parameters. This also may improve the reliability of TES motor evoked potential monitoring.

Electric Impedance↗
PubMed2004

Improved neuromonitoring during spinal surgery using double-train transcranial electrical stimulation.

Motor evoked potentials (MEPs) evoked by transcranial electrical stimulation (TES) have become an important technique for monitoring spinal cord function intra-operatively, but can fail in some patients. A new technique of double-train stimulation is described. A multipulse transcranial electrical stimulus is preceded by a preconditioning pulse train that leads to larger MEP responses. An MEP monitoring system was adapted for double-train transcranial stimulation (DTS). MEP responses from 160 anterior tibial muscles obtained by double-train stimulation were analysed. All patients received propofol/remifentanil/O2/N2O anaesthesia. Fifty-two (83%) out of 63 single-train tibial MEPs with response amplitudes below 100 microV were magnified to over 100 microV, with an inter-train (inter-stimulus) interval ITI = 10-35 ms. These 63 amplitudes were magnified by an overall logarithmic mean factor of 15.5. For 97 MEPs with amplitudes above 100 microV, the logarithmic mean facilitation factor was 2.4. It was concluded that double-train TES stimulation can markedly facilitate responses to a single stimulus train (STS). The facilitation appears to be most effective when the responses to STS would otherwise be small or absent. This preconditioning stimulation technique is therefore useful when an STS leads to responses that are too small for effective monitoring.

Electric Stimulation↗
PubMed2004

Asymptomatic massive dural ectasia associated with neurofibromatosis type 1 threatening spinal column support: treatment by anterior vascularized fibula graft.

We report the case of a girl with a dystrophic neurofibromatosis lumbar scoliosis with asymptomatic progression and spread of dystrophic characteristics over 18 years. Resorption of almost the entire anterior column of L1-L4 had occurred despite a previous posterior instrumentation and fusion. A vascularized fibula bone graft wrapped in titanium mesh was used as an anterior structural graft. With close follow-up, the need for this type of salvage surgery might have been averted. Further follow-up showed no graft resorption and unchanged sagittal alignment after 3 years.

Adolescent↗
PubMed2002

Total disc replacement for chronic low back pain: background and a systematic review of the literature.

In this paper the rationale for total disc replacement is discussed, and the authors suggest seven requirements that should be met before the implantation of these devices can be accepted as regular procedures. In an attempt to answer the questions raised, a systematic literature search was performed. The search yielded no controlled trials and nine case series with a total of 564 arthroplasties in 411 patients. The devices used were SB Charité in eight and Acroflex in one study. The percentage results classified as "good" or "excellent" in the studies varied from 50 to 81%. Complications were observed in 3-50% of the patients. Twenty-two of the operated levels were fused either spontaneously or after additional surgery. A meta-analysis to compare the results with other treatments could not be performed due to the lack of comparative studies. Despite the fact that these devices have been implanted for almost 15 years, on the basis of this literature survey there are currently insufficient data to assess the performance of total disc replacement adequately. There is no evidence that disc replacement reliably, reproducibly, and over longer periods of time fulfils the three primary aims of clinical efficacy, continued motion, and few adjacent segment degenerative problems. Total disc replacement seems to be associated with a high rate of re-operations, and the potential problems that may occur with longer follow-up have not been addressed. Therefore, total disc replacements should be considered experimental procedures and should only be used in strict clinical trials.

Arthroplasty, Replacement↗
PubMed2002

[The disc prosthesis: myths and facts].

The results of surgical treatment of degenerative low-back conditions by means of a fusion (spondylodesis) are in general less predictable than operative treatments for arthrosis of the (large) peripheral joints. Recently, new techniques of disc replacement have been developed as an alternative to traditional fusion operations. The most important theoretical advantage is the prevention of adjacent segment degeneration in the longer term. Because the disc prosthesis replaces the presumably painful intervertebral disc--just as an intercorporal fusion--the short-term results are expected to be comparable to ventral fusion. The results with a short follow-up period described in the literature are comparable to those published for spondylodesis. However, disc prosthesis requires a more extensive approach and therefore more serious complications are to be expected. In the longer term, prosthesis-related complications can be expected because these prostheses are used in young and active patients. Despite 15 years of small-scale experience in some European countries, there is a lack of reliable information about the middle and long-term performance of these prostheses in the peer-reviewed literature. Therefore, these implantations should be regarded as experimental procedures and should be confined to clinical trials in centres with sufficient experience in the operative treatment of degenerative low-back conditions as well as the necessary infrastructure to follow up these usually young patients in a scientifically responsible manner over a period of decades. These centres should also have the expertise necessary to adequately deal with the possible complications.

Humans↗
PubMed2001

A new application of TCE-MEP: spinal cord monitoring in patients with severe neuromuscular weakness undergoing corrective spine surgery.

The importance of spinal cord monitoring during corrective scoliosis surgery is widely acknowledged. However, for patients with preoperative neurologic deficits, its use is technically difficult. In this article, we describe intraoperative transcranial electrical motor evoked potential (TCE-MEP) monitoring in nine patients with neuromuscular weakness who underwent corrective scoliosis surgery. In each patient, eight muscle groups were recorded and stable responses were obtained in all patients. We conclude that TCE-MEP permits monitoring of the spinal cord in patients with disturbed motor function.

Adolescent↗
PubMed1999

Acetabular coverage of the femoral head after triple pelvic osteotomy: no relation to outcome in 51 hips followed for 8-15 years.

In developmental dysplasia of the hip in adolescents and young adults, pelvic osteotomies aim to improve acetabular coverage of the femoral head by reorienting the acetabulum. We determined whether acetabular coverage is related to long-term clinical results after triple osteotomy of the pelvis. We used a previously published computer program (Konishi and Mieno 1993) which calculates three-dimensional coverage of the femoral head from plain anteroposterior radiographs. We studied the pelvic radiographs of 51 hips in 43 patients and the results were correlated with studies on clinical outcome (de Kleuver et al. 1997). Total acetabular coverage improved from a mean of 56% to 70%. We did not find a relationship between total acetabular coverage and long-term outcome, nor could we determine an optimal coverage. Reduced coverage of the posterolateral quadrant of the femoral head was related to a reduced score for walking ability (p = 0.03), and therefore care should be taken not to overcorrect the acetabulum forwards when attempting to improve the deficient anterior coverage. We challenge the concept that total acetabular coverage is a prerequisite for a good long-term outcome after triple pelvic osteotomy, and hypothesize that other factors such as the change in load across the hip are probably more important in determining the outcome.

Acetabulum↗
PubMed1998

Pelvic osteotomies: anatomic pitfalls at the pubic bone. A cadaver study.

Pelvic osteotomies for acetabular dysplasia include an osteotomy of the pubic bone. The anatomical consequences of two different approaches to the pubic bone were assessed by performing a triple osteotomy on a series of 12 fresh cadaver hemipelvises. The medial approach through a separate incision over the pubic symphysis was compared with the lateral approach through the incision used for the innominate osteotomy. Although the medial approach appears technically easy, there are several anatomical structures at risk, such as the femoral vein and the corona mortis. The lateral approach is safer, and it is easier to make the osteotomy close to the hip joint. The closer the osteotomy is to the hip joint, the smaller the chance of developing a non-union.

Acetabulum↗
PubMed1998

Pelvic osteotomies: anatomic pitfalls at the ischium. A cadaver study.

Pelvic osteotomies for acetabular dysplasia include an osteotomy of the ischium. The potential anatomical hazards of three different osteotomies of the ischium were assessed by performing a triple osteotomy in a series of 8 fresh cadaver pelvises. An oblique osteotomy above the sacrospinous ligament using a posterior approach requires that the inferior gluteal and pudendal neurovascular bundles be mobilised and retracted. A transverse osteotomy below the sacrospinous ligament using a posterior approach can be performed in a relatively safe area between the pudendal and sciatic nerves. A transverse osteotomy from anterior can be performed through a modified Smith Peterson approach. The pudendal nerve medially, the sciatic nerve laterally and the medial circumflex artery distally are not visualised and are prone to damage.

Cadaver↗
PubMed1998

Polysegmental lumbar posterior wedge osteotomies for correction of kyphosis in ankylosing spondylitis.

Between 1984 and 1993 we treated 21 consecutive patients who had progressive thoracic kyphosis due to ankylosing spondylitis by polysegmental posterior lumbar wedge osteotomies. In 19 patients we used the Universal Spinal Instrumentation System and in the last 2 patients the H-frame. The average correction in 20 of 21 patients at follow-up was 25.6 degrees (range 0 degrees-52 degrees), with a mean segmental correction of 9.5 degrees and a mean loss of correction after operation of 10.7 degrees (range 0 degrees-36 degrees). There were no fatal complications, but in one patient no correction could be obtained during surgery and another patient was reoperated due to lack of correction. Breaking out of screws through the pedicle during compressive correction was seen in seven patients. Implant failure, such as breakage of the threaded rods and/or loosening of the junction between the pedicle screw and the rod, occurred in 9 out of 21 patients. Two patients required reoperation at long-term follow-up. Five out of seven deep wound infections required removal of the implant. Polysegmental lumbar wedge osteotomies for correction of progressive thoracic kyphosis in ankylosing spondylitis is only recommended in patients at a mild stage of the disease with mobile discs and in combination with strong instrumentation.

Adult↗
PubMed1998

Aneurysmal bone cyst of the spine: 31 cases and the importance of the surgical approach.

Thirty-one cases of aneurysmal bone cyst of the spine with a minimum follow-up of 1 year as registered by the Netherlands Committee for Bone Tumors are reported. Aneurysmal bone cyst is a benign, sometimes expansive and destructive, lesion frequently occurring between the ages of 10 and 20 years. Located in the vertebral column, it undermines the structural integrity of the spine, and neurologic complications can occur. In all cases the posterior elements were involved, with extension into the vertebral body occurring in 22 cases. Extension to adjacent vertebra occurred 5 times, but the intervertebral disc appeared to be left intact. Twenty-nine of 31 cases were treated surgically. Posterior approaches provided insufficient access to lesions also located to the vertebral body and were associated with a higher recurrence rate (5 of 18 cases) than anterior approaches (1 of 11 cases). Of 10 cases in which the surgical removal was incomplete, 4 healed and 6 had a local recurrence. Selective embolization was used twice, and its application is discussed. On the basis of this material and a review of the literature, treatment by intralesional curettage combined by adjuvant therapy such as preoperative embolization is advised.

Adolescent↗
PubMed1998

Three-dimensional displacement of the hip joint after triple pelvic osteotomy. A postmortem radiostereometric study.

Triple pelvic osteotomy reorients the acetabulum relative to the pelvis in order to improve acetabular coverage of the femoral head in cases of acetabular dysplasia. We undertook a radiostereometric analysis (RSA) on 6 osteotomized cadaver hips to determine the actual three-dimensional reorientation obtained. The centers of the femoral head were all translated posteriorly between 11 and 41 mm, and distally up to 13 mm. 4 were lateralized up to 8 mm, and 2 were medialized up to 5 mm. All acetabuli rotated anteriorly about the lateral to medial axis (X-axis), and 4 rotated outwards around the distal to proximal axis (Y-axis). The correlations between measurements performed on conventional anteroposterior radiographs and the RSA measurements were poor: variations in the lateral-medial direction ranged from -16 to +6 mm, and in the distal-proximal direction between -10 and +12 mm. The changes in orientations measured will significantly affect the load across the hip joint, since the dimensions of the pelvis change and the moment arms of the muscles, their lengths and lines of action are changed as well. We conclude that, with the procedures presently performed, the loads across the hip joint are bound to change, and that the reorientation can hardly be checked with conventional radiographs.

Acetabulum↗
PubMed1998

Anatomic basis of Tönnis' triple pelvic osteotomy for acetabular dysplasia.

Dysplasia of the hip in adults can be treated by a pelvic osteotomy. In order to assess pelvic anatomy in relation to surgical approach and osteotomy sites, 12 cadaver hips were studied. A triple pelvic osteotomy as described by Tönnis [6] through ilium, pubis and ischium was performed, followed by an intrapelvic and anterior and posterior dissection of the hip. At the ischium, the pudendal and inferior gluteal neurovascular bundles are most at risk medially and proximally respectively. Much less in danger is the sciatic n. as it runs 1 to 3 cm lateral to the osteotomy site. At the pubis osteotomy the femoral v. lies close on the bone and is prone to damage. The artery lies further off the bone. The ilium osteotomy starts just proximal to the anterior inferior iliac spine and exits posteriorly at the sciatic notch. Here the sciatic n. and the superior gluteal neurovascular bundle may be damaged. The practical surgical implications of these three osteotomies are discussed, especially with respect to the requirement of meticulous subperiostal dissection and accurate placement of retractors.

Acetabulum↗
PubMed1997

Triple osteotomy of the pelvis for acetabular dysplasia: results at 8 to 15 years.

Reorientation of the acetabulum may be required in adolescents and young adults with developmental dysplasia of the hip. We have carried out a retrospective review of 51 hips after triple osteotomy with an average follow-up of ten years (8 to 15). Forty-eight hips (94%) were available for review and of these 39 (81%) were improved compared with before operation, 29 (60%) scoring good or excellent. Radiographic assessment showed improvement of the average centre-edge angle by 19 degrees, the acetabular index by 12 degrees and the anterior centre-edge angle by 26 degrees. The degree of osteoarthritis progressed by one grade in ten hips (21%) over a period of ten years. The satisfactory long-term clinical and radiographic results have encouraged us to continue this treatment for symptomatic acetabular dysplasia in these patients.

Acetabulum↗