Bone Decompression Research Articles

Intraoperative ultrasonography used to determine the extent of surgery necessary during posterior fossa decompression in children with Chiari malformation Type I

In this retrospective analysis, the authors report a prospective study in which intraoperative ultrasonography was used to determine the extent of surgery necessary during posterior fossa decompression surgery for Chiari malformation Type I (CM-I) in children. Between 1995 and 2003, posterior fossa decompression was performed in 149 patients (mean 5.9 years of age, range 9 months-18 years of age) with CM-I. Of these, 130 underwent intraoperative ultrasonographic evaluation of the craniocervical junction (CCJ) and 15 did not. Four patients with craniosynostosis were excluded from the study. Duraplasty and tonsillar shrinkage were performed when ultrasonographic evidence showed significant decreases in cerebrospinal fluid (CSF) or abnormal tonsillar piston action. Surgical success was determined on the basis of clinical outcome and need for reoperation. One hundred and twenty-four (95.5%) of the children had successful outcomes following surgery and six (4.5%) experienced continued or worsening symptoms requiring reoperation. Forty patients did not undergo duraplasty because the ultrasonography evidence showed adequate decompression with bone removal alone. Of 90 patients with significant compression, decreased CSF dynamics, and/or abnormal tonsillar piston-like action at the CCJ, 85 underwent duraplasty and tonsillar shrinkage and five did not for various reasons. One patient in whom the dura mater was violated accidentally during bone decompression subsequently underwent duraplasty. Hospital stays lasted 6.4 +/- 3.9 days (mean +/- standard deviation) when duraplasty was performed compared with 4.3 +/- 1.1 days when it was not (p < 0.0003). After bone decompression alone, no patient experienced complications. After duraplasty, 12 patients experienced complications and had headaches, nausea, and pain more often than patients who underwent bone decompression alone. Mean tonsillar descent was 11 +/- 4 mm after bone decompression only and 13.9 +/- 4.9 mm after duraplasty, with tonsillar shrinkage (p < 0.0003) seen on magnetic resonance imaging. In patients who undergo decompressive surgery for CM-I, intraoperative ultrasonography may be a useful tool to aid the surgeon in deciding whether to opt for bone removal only or bone removal plus duraplasty and tonsillar shrinkage.

Transforniceal Lateral Deep Bone Decompression—A Modified Technique to Prevent Postoperative Diplopia in Patients with Disfiguring Exophthalmos Due to Dysthyroid Orbitopathy

Postoperative diplopia remains a significant complication of orbital decompression in dysthyroid orbitopathy. This study evaluated the results of orbital decompression treatment using a transforniceal approach to sculpt the lateral orbital deep bone area. The two areas of bone in the deep lateral orbit (the basin of the inferior orbital fissure and the sphenoid door jamb) were exposed using a transforniceal swinging eyelid approach. An electric drill was used to sculpt these deep bone areas of the lateral orbit, and approximately 1 mL intraconal fat was removed simultaneously. Between October 1999 and March 2003, transforniceal lateral deep bone decompression was performed in 35 consecutive patients (62 orbits) with disfiguring dysthyroid orbitopathy. Data on proptosis reduction effect, new-onset diplopia and other complications of lateral wall decompression were analyzed. The average preoperative Hertel value was 21.2 +/- 1.3 mm (range, 18-23 mm) and decreased to 17.4 +/- 1.2 mm (range, 15-19.5 mm) postoperatively. The mean decrease in proptosis 3 months postoperatively was 3.8 +/- 0.91 mm (range, 1.5-4.6 mm). New-onset downgaze diplopia occurred in two (5.7%) of the 35 patients. Persistent trigeminal paresthesia was noted in one patient (2.8%). No cerebrospinal fluid leak, globe injury or vision deterioration was noted during 9.5 +/- 1.7 months of follow-up. The cosmetic appearance was improved in all patients after surgery. Transforniceal lateral deep bone decompression produces less new-onset, persistent diplopia than traditional inferomedial wall decompression, and provides good cosmesis by using a hidden small incisional wound. This approach appears to be a safe and effective procedure for patients with disfiguring exophthalmos, especially for Asian patients without crease fold.

Intraoperative evaluation of bone decompression in anterior cervical spine surgery by three-dimensional fluoroscopy

Sufficient bone decompression of osteophytes is essential for functional long-term outcome in surgery for spondylotic cervical myelopathy. Postoperative CT scans clearly show that decompression is sometimes insufficient. Intraoperative CT scanning has been used to monitor sufficient decompression. Instead of standard intraoperative fluoroscopy, we used an isocentered three-dimensional (3D) fluoroscopy with 3D image reconstruction to evaluate the extent of bone decompression. From October 2003 to April 2004, we have used intraoperative 3D fluoroscopy on seven patients with anterior cervical spine surgery due to cervical spondylotic myelopathy. Five patients were operated on in one level, two patients had surgery in two segments. If surgery was performed in two levels or preoperative cinetic MRT showed cervical instability, internal plate fixation was done additionally. All patients were positioned on a radiolucent operating table, made of carbon fibers. Three-dimensional fluoroscopy was always performed before wound closure to evaluate sufficient bone removal. The scanning time was 120 s and the whole procedure from scanning to evaluation is approximately 5 min. In all patients we were able to evaluate the extent of bone decompression. Additionally, placement of cage, plates and screws can be evaluated intraoperatively. In one patient, 3D fluoroscopy showed insufficient decompression, especially on the right side. Further bone removal was performed before the end of the procedure. Intraoperative 3D fluoroscopy is a valuable tool for imaging bone decompression and implant location in anterior cervical spine surgery. The technique is safe, reliable and should help us to avoid incomplete decompression or misplacement of implants and therefore improve long-term functional outcome in cervical spine surgery in the future.

La diplopie est-elle un facteur déterminant du choix de la technique de décompression orbitaire au cours de l’orbitopathie dysthyroidienne ?

Dysthroid orbitopathy or Graves ophthalmopathy is a frequent pathologic condition five times more frequent in females than males. The main symptoms are: proptosis, motility disorders related to eye muscles fibrosis, eyelid retraction, lagophthalmos, and finally the more severe ones: compressive optic neuropathy at the apex of the orbit, and corneal exposure. In order to reduce proptosis the classic approach is Bone Removal Orbital Decompression (BROD) either through eyelid skin, coronal, conjunctival, or endonasal approaches. Recently a new technique has been described by Olivari: Fat Removal Orbital Decompression (FROD). The purpose is to evaluate the incidence of diplopia after FROD and improve surgical indications for Graves' ophthalmopathy. 35 patients were included in this retrospective study (58 orbits). FROD (OLIVARI technique) was performed in all cases (23 bilateral surgery, 12 unilateral; 12 men, 23 women). All patients with optic neuropathy (severe Graves'ophthalmopathy) were eliminated because bone decompression was always performed. The ocular motility was examined before and after surgery by orthoptic screening. The average follow up was 18 months. Before FROD, 7 patients complained of moderate or severe diplopia: all remained with diplopia after FROD. After FROD 32% developed a new diplopia: only one patient remained with diplopia after strabismus surgery or adaptation by prisms glasses. Diplopia after BROD in moderate Graves' ophthalmopathy (with indications identical to our study) is reported from 23 to 34% in previous studies. Diplopia after FROD is a real risk whose incidence is identical after FROD and BROD and must be explained to each patient before surgical decision.

Improvement in brainstem auditory evoked potentials after suboccipital decompression in patients with chiari I malformations.

The optimal treatment for patients with symptoms related to Chiari I malformation remains controversial. Although a suboccipital decompression with duraplasty is most commonly performed, there may be a subset of patients who improve in response to bone decompression alone. In an initial attempt to identify such patients, we performed a continuous study of intraoperative brainstem auditory evoked potentials (BAEPs) in patients undergoing a standard decompression with duraplasty and compared conduction times at three different time points: 1) baseline while the patient is supine (before positioning); 2) immediately after opening of the bone and release of the atlantooccipital membrane (that is, the dural band); and 3) after opening of the dura mater. Eleven children and young adults (mean age 9.8 years) with symptoms related to Chiari I malformation underwent suboccipital decompression and duraplasty with intraoperative monitoring of BAEPs and somatosensory evoked potentials (SSEPs). Six patients (55%) had associated syringomyelia. At baseline, the I to V interpeak latency (IPL) for both sides (total 21 BAEPs) was 4.19 +/- 0.22 msec (mean +/- standard deviation). After complete bone decompression and before the dura mater was opened, the I to V IPL decreased to 4.03 +/- 0.25 msec (p = 0.0005). When the dura was opened, however, no further decrease in the I to V IPL was detected (4.03 +/- 0.25 msec; p = 0.6). The SSEPs remained stable throughout the procedure. In children and young adults undergoing suboccipital decompression with duraplasty for Chiari I malformation, the vast majority of improvement in conduction through the brainstem occurs after bone decompressionand division of the atlantooccipital membrane, rather than after opening of the dura. Additional studies are needed to establish whether the improvement seen with BAEP monitoring during bone decompression will predict long-term clinical improvement in these patients.

"Balanced" orbital decompression for severe Graves' orbitopathy: technique with treatment algorithm.

Graves' orbitopathy can produce proptosis, compressive optic neuropathy, and extraocular motility abnormalities; symptoms result from an increase in orbital volume due to expansion of intraorbital fat, with or without extraocular muscle involvement. We conducted a chart review of patients who underwent orbital decompression to treat Graves' orbitopathy. Twenty-two orbits (13 patients) underwent orbital bone decompression, of which 17 orbits (9 patients) underwent the combined medial and lateral "balanced" decompression. All patients had significant improvement with an average decrease in proptosis of 5.9 mm in the balanced decompression group. Restoration of normal optic nerve function was achieved in all patients with compressive optic neuropathy. Diplopia was noted in 4 patients (30.7%) preoperatively. Two patients had new postoperative diplopia (15.35%). In our experience, "balanced" decompression results in a reduction of proptosis and improved optic nerve function and has a low incidence of complications.

Treatment of the Chiari malformation with bone decompression without durotomy in children and young adults.

The purpose of this study was to provide more information on alternative operative approaches to the treatment of symptomatic Chiari type I and/or type II malformations in children and young adults. All patients were treated with craniocervical decompression without durotomy or duroplasty. The cervical decompression was carried on to the lowest level of tonsillar herniation. In 22 patients with symptomatic Chiari type I (4) and/or Chiari type II (18) malformation, there was total improvement in 12, partial improvement in 7, and no change in 3. There was no operative morbidity or mortality. Craniocervical decompression without durotomy may be a suitable treatment modality for symptomatic Chiari malformation in children and young adults.

The surgical technique and the age of the horse both influence the outcome of mosaicplasty in a cadaver equine stifle model.

Six pieces of grafts, 6.5 mm in diameter, 20 mm in length, were taken from each of 170 cadaver hindlimbs, using the cranial surface of the medial femoral trochlea for harvesting. The age of the horses varied between 4 months and 23 years. 30 limbs under the age of 12 years were selected for transplantation. Three of six grafts were transplanted into the medial femoral condyle using different combinations of tunnel depth and dilation. With ageing, a significant decline in transplantability was detected. In general, mosaicplasty cannot be recommended in horses above 11 years. Based on a previous clinical case (Bodó et al., 2000), a good surface alignment was indeed achieved with a combination of graft length drilling and dilation in most cases. However, the occasional entrapment of cartilage debris under the graft prevented perfect alignment in the present cadaver study in 27% of the grafts transplanted in this manner. Since the protrusion of grafts never exceeded 1.5 mm, we conclude that drilling 3-5 mm deeper than graft length with graft length deep dilation can avoid disadvantageous protrusion of the transplanted hyaline cartilage caps, achieving bone decompression at the same time.

Reversal of dysthyroid optic neuropathy following orbital fat decompression

AIMSTo document the successful treatment of five patients with dysthyroid optic neuropathy by orbital fat decompression instead of orbital bone decompression after failed medical therapy.METHODSEight orbits of five patients with...

The role of decompressive craniectomy in the treatment of uncontrollable post-traumatic intracranial hypertension.

The benefit of decompressive craniectomy for the treatment of uncontrolled post-traumatic intracranial hypertension seems to be encouraging if medical management fails. We present our experience in 22 cases of cerebral edema due to head trauma. The edema alone was rarely the direct consequence of head trauma. Frequently it was associated with an acute subdural or extradural hematoma and contusion (with or without mass effect). First of all we treated the mass effect of the hematoma and contusion when the diameter was more than 3 cm. Intracranial pressure was monitored in the majority of patients. Bone decompression was performed in the operating theatre depending on the values of intracranial pressure. In our series 41% of patients had a good recovery, 18% a severe disability, 23% a vegetative state and 18% died. The findings showed that the bony decompression must be performed early before the situation becomes irreversible. We suggest that if intracranial pressure values remain greater than 30 mmHg with cerebral perfusion pressure below 70 mmHg, despite vigorous anti-edema therapy, decompressive craniectomy should be considered.

Endoscopic foraminotomy using a microendoscopic discectomy system in cadaveric specimens

Although the anterior approach is more commonly performed for the treatment of cervical disc disease, the posterior approach has distinct advantages in selected cases of foraminal stenosis and posterolateral disc herniation. The authors performed cervical key hole foraminotomies using a microendoscopic discectomy (MED) system in four cadaveric cervical spine specimens to evaluate this minimally invasive surgical approach for cervical disc diseases. The amount of bone decompression achieved by using the MED system was compared with that achieved by using the open foraminotomy procedure in each cadaveric specimen. Three noncontiguous cervical nerve roots were selected between C-3 and C-8 in each specimen and were decompressed using the MED system on one side and using the open foraminotomy procedure on the contralateral side. Postoperative computerized tomography (CT) myelography showed that adequate bone decompression was achieved by using either the MED or open procedure in all specimens. Postoperatively, open dissection was performed to confirm and compare the amount of decompression in both the MED and open procedures. The laminotomy size (vertical and transverse diameter), the length of decompressed nerve root, and the proportion of removed facet joint were measured on every operative level. The average vertical diameter of laminotomy area and the percentage of facet removed were significantly greater in the MED procedure than the open procedure (p &lt; 0.05). The transverse diameter of the laminotomy area and the average decompressed root length were not significantly different between MED and open surgery. The authors conclude that endoscopic cervical foraminotomy using the MED system is a feasible procedure and may be clinically applicable in the treatment of foraminal stenosis and laterally located cervical disc herniation.

Fatal tumoural haemorrhage following decompressive craniectomy: a report of three cases

Three cases of large and deep seated anaplastic cerebral glioma were treated by bone and dural decompression. The patients worsened suddenly within 12 h of surgery and later died. Postmortem examination revealed a large intratumoural clot in each case. The effects of decompression and the probable causes of fatal bleeding are analysed in this report.

A Risk/Benefit Analysis of Spinal Manipulation Therapy for Relief of Lumbar or Cervical Pain

APPROXIMATELY 12 MILLION Americans undergo spinal manipulation therapy (SMT) every year. Renewed interest in this method requires an analysis of its reported risks and possible benefits. This review describes two patients with spinal cord injuries associated with SMT and establishes the risk/benefit ratios for patients with lumbar or cervical pain. The first case is a man who underwent SMT for recurrent sciatica 4 years after chemonucleolysis. During therapy, he developed bilateral sciatica with urinary hesitancy. After self-referral, myelography demonstrated a total block; he underwent urgent discectomy with an excellent result 3 months after surgery. The second patient with an indwelling Broviac catheter and a history of lumbar osteomyelitis underwent SMT for neck pain. Therapy continued for 3 weeks despite the development of severe quadriparesis. After self-referral, he underwent an urgent anterior cervical decompression and removal of necrotic bone and an epidural abscess with partial neurological recovery. An analysis of these cases and 138 cases reported in the literature demonstrates six risk factors associated with complications of SMT. These include misdiagnosis, failure to recognize the onset or progression of neurological signs or symptoms, improper technique, SMT performed in the presence of a coagulation disorder or herniated nucleus pulposus, and manipulation of the cervical spine. Clinical trials of SMT have been summarized in several recent articles. Although these reviews agreed that most trials exhibited serious flaws, the data suggest that SMT demonstrates consistent effectiveness as an alternate treatment for adults with acute low back pain. SMT has not been shown to be superior to other conservative methods, nor to offer long-term benefits. It is concluded that the risk/benefit ratio is acceptably low for SMT as therapy for adults with midline low back pain of less than 1 week in duration. The ratio was unacceptably high for patients with radicular symptoms or signs associated with prolapsed discs and neck pain. Potential complications and unknown benefits indicate that SMT should not be used in the pediatric population.

A Risk/Benefit Analysis of Spinal Manipulation Therapy for Relief of Lumbar or Cervical Pain

Approximately 12 million Americans undergo spinal manipulation therapy (SMT) every year. Renewed interest in this method requires an analysis of its reported risks and possible benefits. This review describes two patients with spinal cord injuries associated with SMT and establishes the risk/benefit ratios for patients with lumbar or cervical pain. The first case is a man who underwent SMT for recurrent sciatica 4 years after chemonucleolysis. During therapy, he developed bilateral sciatica with urinary hesitancy. After self-referral, myelography demonstrated a total block; he underwent urgent discectomy with an excellent result 3 months after surgery. The second patient with an indwelling Broviac catheter and a history of lumbar osteomyelitis underwent SMT for neck pain. Therapy continued for 3 weeks despite the development of severe quadriparesis. After self-referral, he underwent an urgent anterior cervical decompression and removal of necrotic bone and an epidural abscess with partial neurological recovery. An analysis of these cases and 138 cases reported in the literature demonstrates six risk factors associated with complications of SMT. These include misdiagnosis, failure to recognize the onset or progression of neurological signs or symptoms, improper technique, SMT performed in the presence of a coagulation disorder or herniated nucleus pulposus, and manipulation of the cervical spine. Clinical trials of SMT have been summarized in several recent articles.(ABSTRACT TRUNCATED AT 250 WORDS)

Orbital Fat Removal: Decompression for Graves Orbitopathy

Orbital decompression has been used to describe surgical procedures that remove some portion of the orbital walls to reduce pressure on the orbital contents. Substantial morbidity associated with these procedures includes infraorbital anesthesia, worsened extraocular motility, globe displacement, and blindness. The authors believe that orbital contents also may be decompressed by removing orbital fat. Eighty-one patients with nonactive Graves orbitopathy were selected for orbital fat decompression based on the presence of proptosis and associated signs and symptoms to avoid bone removal. Soft-tissue analysis by computed tomography (CT) scan showed distended pockets of fat extending into the intraconal space, which were removed through medial-upper and lateral-lower anterior orbitotomies. Decompression with bone removal was reserved for those few patients with compressive optic neuropathy unresponsive to medical treatment and those patients with residual deforming exophthalmos after fat removal. One hundred fifty-eight fat decompressions were performed on 81 patients over 9 years. The authors measured an average reduction in proptosis of 1.8 mm (range, 0-6.0 mm). The greatest average reduction in proptosis (3.3 mm) was produced in patients with preoperative Hertel measurements of greater than 25.0 mm. Morbidity was limited to temporary motility impairment of the inferior oblique in two patients. The concept of orbital decompression can include removal of orbital fat to reduce proptosis, eliminate symptoms, and improve appearance with far less morbidity than when bone decompression is used as the primary decompressive procedure.

Posterior Fossa Venous Angioma – Can it be Resected?: Review of the Literature through a Case Report

Posterior Fossa Venous Angioma – Can it be Resected?: Review of the Literature through a Case Report

Surgical treatment for Graves' disease

The functional and esthetic consequences of Graves' disease can be corrected by surgical procedures according to a well-established methodology: (1) Orbital decompression for exophthalmos, (2) Lengthening of the levator muscle in case of palpebral retraction, (3) Lengthening of fibrotic eye muscles in case of diplopia.Not infrequently these sequelae coincide and one or more operative sessions become necessary. The timing of these sessions is dependent on the interactions that exist between the orbit, the eyelids and the ocular motor muscles. Sometimes the treatment of one single symptom interferes with the other functions. Orbital surgery - orbital decompression or removal of bone - is primarily intended to counteract the exophthalmos. The decompression, however, may modify the function of the ocular motor muscles or of the palpebral motility.Ocular motor surgery comes second after correction of the orbit and always must precede the surgery of eyelids because the position of the eyelids is largely depende...

Group B Streptococcal Osteomyelitis and Septic Arthritis

Nine infants less than 2 months of age with group B streptococcal (GBS) osteomyelitis or septic arthritis, or both, were seen from January 1975 through January 1978. The infants had local joint signs, usually in the absence of systemic signs. The bones and joints involved were equally distributed between proximal humerus and proximal and distal femur. An infant had involvement of the talus. Treatment consisted of two to three weeks of parenteral antibiotics, arthrotomy in infants with arthritis, and bone decompression in infants with osteomyelitis. Clinical follow-up showed normal growth and function of the affected joint. Of the organisms, five were typed: four were type III and one was type Ib. Group B streptococcal osteomyelitis and/or septic arthritis was the second most common late-onset GSB infection, being surpassed only by meningitis.