Influence of cranioplasty on postural blood flow regulation, cerebrovascular reserve capacity, and cerebral glucose metabolism

Facet cyst in the lumbar spine: radiological and histopathological findings and possible pathogenesis

Object

The authors define facet cyst as a cyst located beside the facet joint and exhibiting a communication with the joint, as demonstrated on arthrography and subsequent computed tomography (CT) of the joint space. The purpose of this study was to determine the pathogenesis of facet cysts based on their radiological and histological features.

Methods

Forty-six juxtafacet cysts in 45 patients (26 men and 19 women, age range 41–82 years) were surgically treated after evaluation by arthrography and subsequent CT scanning. A communication channel between the cyst and the joint was confirmed in all cases and thus the lesions were designated facet cysts. In almost all patients the involved facet joint showed moderate to severe degeneration. After a thorough preoperative radiological evaluation, these cysts were excised en bloc by medial facetectomy with the entire ligamentum flavum. The specimens were cut axially at the maximum diameter and were histologically investigated.

Morphologically, the cysts exhibited three shapes, appearing as: 1) a small protrusion, 2) a semicircular cyst, or 3) a round cyst. The cyst walls consisted of elastic and collagen fibers undergoing fibrinoid degeneration, but no synovial lining cells were detected. The cystic cavities were regularly filled with fibrinoids, and myxoid degeneration was found particularly in the larger cysts.

Conclusions

Facet cysts are closely related to the degeneration of the neighboring facet joint. Analysis of the findings in this histological study suggests that there are several shapes of facet cysts. The authors propose that the shape could depend on the stage of the cyst’s development.

Predictive factors for dural tear and cerebrospinal fluid leakage in patients undergoing lumbar surgery

OBJECT

A dural tear resulting in a cerebrospinal fluid (CSF) leak is a well-known risk of lumbar spinal procedures. The authors hypothesized that the incidence of CSF leakage is higher in cases involving repeated operations and those in which the surgeon performing the surgery is less experienced; however, they postulated that the overall outcome of the patient would not be adversely affected by a dural tear.

METHODS

An institutional review board-approved protocol at Louisiana State University Health Sciences Center, Shreveport, was initiated in August 2003 to allow prospective comparison of data obtained in patients in whom a CSF leak occurred (Group A) and those in whom no CSF leak occurred (Group B) during lumbar surgery. Basic demographic information, descriptive findings regarding the tear, history of other surgeries, hospital length of stay (LOS), and immediate disposition at the time of discharge were compared between the two groups. Seventy-seven patients were eligible for this study. One patient refused to participate. In 12 (15.8%) of 76 patients CSF leakage developed. In three patients the presence of a tear was questioned, and the patients were clinically treated as if a tear were present. The patients in Group A were older than those in Group B (59.8 +/- 16.9 and 49.4 +/- 13.6 years of age, respectively; p = 0.02, Fisher exact test). In terms of those with a history of surgery, there was no significant difference between patients with and patients without a CSF leak (three [25%] of 12 patients [Group A] compared with 28 [43.8%] of 64 patients [Group B]; p = 0.34, two-sample t-test). In the 12 patients with dural tears, nine (75%) were caused by a resident-in-training, and the Kerrison punch was the instrument most often being used at the time (55%). This is significantly greater than 50% at the 5% level (p = 0.044, binomial test). The authors were able to repair the tear primarily with suture in all but one patient, whose tear was along the nerve root sleeve. In all cases fibrin glue and a muscle/fat graft were used to cover the tear, and all patients were assigned to bed rest from 24 to 48 hours after the operation. In Group A one patient required rehabilitation at discharge. The LOS in Group A was greater than that in Group B (median 5 days compared with 3 days), but no additional complication was noted.

CONCLUSIONS

The incidence of CSF leakage was 16% in 76 patients, and there were no other complications. Older patient age and higher level of the surgeon's training were factors contributing to the incidence, but the history of surgery was not.

Far Lateral Extraforaminal Facet Cyst Causing L5 Radiculopathy

Most synovial cysts of the lumbar spine appear as intraspinal extradural masses adjacent to the facet joint. Almost all symptomatic synovial cysts are located within the spinal canal and or the neural foramen. To our knowledge, only 6 cases of symptomatic extraspinal synovial cysts have been described in the literature. The authors report a case of lumbar radiculopathy caused by a synovial cyst located in the far lateral extraforaminal area. The patient underwent decompression of the L5 nerve root with recapping right isthmectomy and facetectomy. Postoperative recovery was uneventful, and the patient was totally pain free with no motor deficit. Symptomatic synovial cysts are uncommon lesions that are associated with degenerative disease of the spine. Juxtafacet cysts should be considered in the differential diagnosis of space-occupying lesions at the extraforaminal areas. Recapping isthmectomy and facetectomy are useful procedures for a synovial cyst located in the far lateral extraforaminal area.

Silicone rubber mould cast polyethylmethacrylate-hydroxyapatite plate used for repairing a large skull defect

INTRODUCTION

Reconstruction of the cranial vault is performed for various reasons and precise repair of the defect is important. A modified method of cranioplasty is presented using three-dimensional (3D) models and polyethylmethacrylate mixed with hydroxyapatite, cast in a silicone rubber mould.

PATIENT AND METHOD

A large custom made cranial implant was produced using data acquired from 3D computer tomography, rapid prototyping and cast in a silicone rubber mould. This plate was then applied to a 53 year-old man who had undergone a decompressive fronto-parieto-temporo-occipital craniotomy. The bone flap had been lost due to infection. The cranioplasty was performed at 1 year after the initial operation.

RESULTS

The cranial plate fitted precisely into the defect and needed no correction at the time of surgery. The stability of the reconstruction plate was increased by the presence of thin margins allowed by silicone rubber elasticity. No complications occurred and the final functional and aesthetic results were good.

CONCLUSION

The use of 3D imaging and rapid prototyping allow precise repair of large skull defects, with good aesthetic and functional results. At the same time, silicone rubber moulds permit the production of very thin details needed not only for cosmetic reasons but for reconstruction plate stability as well.

Early combined cranioplasty and programmable shunt in patients with skull bone defects and CSF-circulation disorders

OBJECTIVE

This study assesses the clinical outcome after early combined cranioplasty (own frozen bone) and shunt implantation (Codman-Medos programmable VP shunt) in patients with skull bone defects and cerebrospinal fluid (CSF) circulation disorders.

METHOD

Medical records were reviewed retrospectively for the last 100 patients with CSF disorders after trauma or subarachnoid hemorrhage (SAH), who previously underwent decompressive craniotomy owing to therapy-resistant brain swelling. Patients treated with early (5 to 7 weeks after injury) combined cranioplasty and shunt implantation were analysed and a follow-up for the survivors was obtained.

RESULTS

In 60 patients with a daily CSF external drainage over 150 ml and dilated ventricles in CT scan, a programmable VP shunt was implanted simultaneously with the cranioplasty within 5.1 weeks after decompression. The neurological condition 6 months later was good (independent patients) in 39 cases (65%); 12 patients (20%) survived with a severe disability; three patients (5%) remained in a persistent vegetative state and only six patients (10%) died. There were few complications: bone or shunt infection (three cases), post-operative intracranial bleeding (one case), transitory neurological impairment after bone reimplantation (two cases), bone resorption (two cases) and shunt dysfunction (three cases).

CONCLUSION

The early reimplantation of the patient's own skull bone combined to the employment of a programmable shunt system allowed us a dynamic adjustment of the intracranial pressure (ICP) changes. The combined treatment reduced the number of required surgical procedures, complications and unsatisfactory patient outcomes.

Synovial cysts associated with cauda equina syndrome in two dogs

OBJECTIVE

To report synovial cysts associated with cauda equina syndrome in 2 dogs.

STUDY DESIGN

Clinical cases.

ANIMALS

Two German Shepherd dogs.

METHODS

After magnetic resonance imaging detection, cysts were surgically removed via dorsal laminectomy.

RESULTS

Six and 8 months after surgery, both dogs were free of clinical signs and no pain was elicited on lumbosacral joint manipulation.

CONCLUSION

Although described in dogs, cysts at the lumbosacral joint might cause compression of the cauda equina nerve roots. Radical excision of the cyst capsule can result in resolution of clinical signs.

CLINICAL RELEVANCE

Synovial cysts should be considered in the differential diagnosis of dogs with cauda equina compression syndrome when lumbosacral degenerative joint disease is present.

Analyses of the factors influencing bone graft infection after delayed cranioplasty

BACKGROUND

Several factors influencing bone graft infection after delayed cranioplasty are analyzed in order to reduce the occurrence of infection.

METHODS

For about 10 years, from March 1995 to February 2005, delayed cranioplasty was performed for 206 cases. The cases comprised 124 males and 82 females. Age distribution of the patients ranged from 6 months to 79 years old. The mean postoperative follow-up period was 1834 days. Autogenous bone, which was preserved in 100% ethanol at -20 degrees C and autoclaved before operation, was used in 54 patients. Polymethylmethacrylate (PMMA) was used in 55 patients. Custom-made PMMA was used in 3 patients. Custom-made titanium mesh was used in 77 patients. Custom-made ceramics (Alumina-ceramics 10 cases and hydroxyapatite 7 cases) was used in 17 patients.

FINDINGS

Autoclaved and autogenous bone graft and PMMA have a significantly high rate of graft infection. Titanium mesh has the significantly lowest rate of graft infection. Alumina-ceramic has a merit that it has sufficient strength, however the number of cases using custom-made ceramics including alumina-ceramic was relatively small, and thus we cannot find significant differences in infection rate compared with that of other materials. There was no statistically significant difference in the bone graft infection rate among four categories of preceding diseases; cerebrovascular diseases, head trauma, infectious diseases, and brain tumour.

CONCLUSION

Autoclaved and autogenous bone grafts and PMMA have a significantly higher rate of graft infection. Titanium mesh has the significantly lowest rate of graft infection.

Retrospective study of 77 patients harbouring lumbar synovial cysts: functional and neurological outcome

BACKGROUND

Synovial cysts represent an uncommon and probably underestimated pathological entity of the degenerative lumbar spine. The authors report a retrospective analysis of the clinical presentation, radiological studies and operative findings in 77 patients surgically treated for symptomatic lumbar synovial cysts at their institution.

MATERIALS AND METHOD

Between January 1992 and June 1998, a total of 77 patients presenting with symptomatic lumbar synovial cysts were operated on in the author's department. Operative procedure, complications, results and pathological findings were correlated with preoperative assessment. There were 41 men and 36 women with an average age of 63 years (range 44-90 years).

RESULTS

On the basis of their symptom complex on presentation, two populations were identified: patients who presented with a single radicular pain (group I = 51 patients), and patients who presented with bilateral neurogenic claudication (group II = 26 patients). Neurological examination on presentation demonstrated motor deficit (12%), sensory loss (26%) and reflex changes (35%). Degenerative disc disease and facet joint osteoarthritis was a frequent finding in patients with pre-operative MRI. Facet joint orientation was >45 degrees in 76.6% of patients. Preoperative spondylolisthesis was found in 48% on radiological studies. All the patients were treated surgically with resection of the cyst. No fusion was performed as a first line procedure. However subsequent fusion was necessary in one patient who developed symptomatic spondylolisthesis. Mean follow-up period was of 45 months ranging from 18 to 105 months. Only one recurrence occurred during the follow-up period. An excellent or good functional outcome was seen in 97.4% of cases, and 89% of the patients with motor deficit recovered.

CONCLUSIONS

Surgical resection of lumbar synovial cysts is an effective treatment associated with very low morbidity. Synovial cysts are associated with increased grade and frequency of facet joint asteoarthritis but not with increased grade or frequency of degenerative disc disease compared with patients without cysts. In the author's opinion, at the present time, there is no reliable criterion which allows the development of a symptomatic spinal instability to be predicted in patients with a preoperative spondylolisthesis and therefore fusion as a first line procedure is still debatable.

Lumbar synovial cysts of the spine: an evaluation of surgical outcome

OBJECTIVE

Our aim was to study the outcomes and results of surgically treated patients with synovial cysts of the lumbar spine in our institution.

METHODS

Retrospective data from 39 consecutive patients, treated during the period of December 1996 to August 2004, were analyzed. Twenty-eight men (70%) and 11 women (30%) of mean age 63.3 years were studied. All pre- and postoperative signs, symptoms, extension/flexion radiographs, magnetic resonance imaging (MRI), and computed tomography (CT) with or without myelography were reviewed. All underwent surgery for synovial cysts with excision and decompression. Additional fusion in 26 patients was performed; 22 of them had degenerative spinal spondylolisthesis. Nine (23%) patients had prior decompression procedures, with three (8%) having had prior spinal instrumentation. Surgical outcomes were evaluated according to a questionnaire scoring system (scale of 1-4; 4 = excellent, 3 = good, 2 = fair, 1 = poor). Various preoperative attributes such as gender, age, weight, and height were analyzed to see if they had any effect on the outcome of surgery. Modified musculoskeletal outcomes data evaluation and management system (MODEM), questionnaire was provided to all; 24 (62%) responded. The following categories were determined: excellent (<20), very good (21-40), good (41-60), fair (61-80), and poor (81-100). Postoperative complications were also recorded.

RESULTS

All patients had pain in their lower extremities, with 62% experiencing pain bilaterally. Ninety-five percent had pain in their back and 36% in the buttocks (36%). Eighteen (46%) patients had CT myelography. A total of 42 cysts were found. Two patients had bilateral cysts at L4-L5 level. Histology revealed two hemorrhagic cysts. The average duration of surgery was 231 minutes (range 92-391 minutes), and a mean blood loss of 930 mL (range 200-2500 mL) was recorded. Two operative dural tears and one postoperative wound dehiscence were observed. One patient had a recurrent synovial cyst at the site of original surgery. Eight patients (four each in the fusion and nonfusion group) had junctional degeneration and symptoms. A regression analysis performed on age, height, weight, and gender showed that they were not determining factors of surgical outcome. Surgery of spinal cysts at L4-L5 segment produced good and those at L5-S1 and multilevel excellent results. Patients with spinal segment fusion had superior outcomes, with 80% having excellent or good outcomes versus approximately 70% without fusion. With the modified MODEM questionnaire, 22 of the 24 (92%) patients scored between excellent, very good, and good. Two patients scored in the fair range, and none of the 24 patients scored in the range of poor.

CONCLUSIONS

Spinal cysts are commonly found at the L4-L5 level, the site of maximum instability. MRI is the tool of choice for diagnosis. The etiology is still unclear, but underlying spinal instability has a strong association for formation of spinal cysts and worsening symptoms. Synovial cysts resistant to conservative therapy should be treated surgically. Resection and decompression with fusion remain an appropriate option. The optimal approach for patients with juxtafacet cysts remains unclear. The best surgical treatment approach for each particular individual appears to remain speculative.

Ligamentum Flavum Hematoma in the Lumbar Spine-Case Report-

A previously healthy 45-year-old woman presented with ligamentum flavum hematoma manifesting as radicular leg pain. Neurological examination findings were consistent with L-5 root compression. An old hematoma inside the degenerated ligamentum flavum was drained. The cyst showed no connection to the facet joint. Complete resection of the mass was performed, resulting in excellent pain relief. The most common cystic lesion in the lumbar spine is synovial cyst associated with the facet joints, but ligamentum flavum hematoma should be included in the differential diagnosis. The preoperative diagnosis can be based on computed tomography and magnetic resonance imaging findings of degenerative thickening of the ligamentum flavum associated with a fluid component.

Taylored implants for alloplastic cranioplasty — clinical and surgical considerations

Traumatic loss of bone substance or post - decompression defects require the reconstruction of the skull. In cases of simple geometry there are handy, secure and cost effective procedures such as using autologuous cryopreserved bone flaps or polymerized Methylmethacrylat. For large sized defects CAD - taylored implants developed to provide a comfortable procedure to ensure high biocompatibility and perfect anatomical results by one - stage surgery. Furthermore cranioplasty does not only imply anatomical reconstruction but also functional recovery of awareness, cognition and motoric functions as shown in several studies according to changes in cerebral hemodynamics and metabolism. In our series of 286 patients who underwent cranioplasty during the past 10 years (1993-2003) we used taylored implants in 15 cases starting in 1999. All the patients included showed large sized defects > 64 cm2, complications did not occur neither during surgery nor the postoperative course, cosmetical results were excellent in all the patients. Neurological findings and the functional state improved in 11/15 patients, 4/15 patients showed no change, nevertheless these patients had reached a good recovery before surgery. Application of this technique is limited by cost, nonetheless it is recommended for extensive reconstruction of the skull.

Hemispheric brain volume replacement with free latissimus dorsi flap as first step in skull reconstruction

Large skull defects lead to progressive depression deformities, with resulting neurological deficits. Thus, cranioplasty with various materials is considered the first choice in therapy to restore cerebral function. A 31-year-old female presented with a massive left-sided hemispheric substance defect involving bone and brain tissue. Computed tomography showed a substantial convex defect involving the absence of calvarial bone as well as more than half of the left hemisphere of the brain, with a profound midline shift and a compression of the ventricular system. There was a severe problem due to multiple deep-skin ulcerations at the depression margin, prone to skin perforation with a probability of intracranial infection. In a first step, a free myocutaneous latissimus dorsi flap was transplanted for volume replacement of the hemispheric brain defect, and 4 months later, artificial bone substitute was implanted in order to prevent progressive vault depression deformity. Healing was uneventful, and the patient showed definite neurological improvement postoperatively. Free tissue transfer can be a valuable option in addition to cranioplasty in the treatment of large bony defects of the skull. Besides providing stable coverage for the reconstructed bone or its substitute, it can also serve as a volume replacement.

Ossifying Fibroma of the Skull: Interactive Image-Guided Minimally Invasive Localization and Resection

Ossifying fibroma is a benign fibro-osseous tumor commonly affecting the craniofacial bones. It is considered to be a locally aggressive and quickly expansible bone lesion. Because of its aggressive nature and high recurrence rate, early detection and complete surgical removal are essential. Usually, these lesions are excised extensively by craniectomy, and bone loss is reconstructed by cranioplasty using acrylic resin or titanium implants. Alternatively, in the management of skull-ossifying fibroma, an image-guided technique using surgical navigation may provide precise information about localization, enabling complete removal, thereby operating with minimal exposure and within narrow resection borders and avoiding significant bone deformity. A 39-year-old male patient with a history of renal cell carcinoma was admitted to our hospital because a radionuclide scintigraphic bone scan revealed increased uptake in a small area located at the left lateral skull bone. The high-resolution computed tomography scan showed that the lesion was located inside the diploe, destroying the inner table of the calvarium. The patient underwent minimally invasive bone lesion removal using an interactive image-guided approach. Complete resection of the neoplastic lesion was achieved. The histopathological examination revealed an ossifying fibroma. The postoperative course was uneventful, and the patient was discharged 3 days after intervention. To date, there has been no evidence of local recurrence. Interactive multimodal planning and intraoperative image guidance offer an interesting approach for biopsy and minimally invasive removal of small ossifying fibroma lesions of the skull, especially in less accessible locations.

New method of pediatric cranioplasty for skull defect utilizing polylactic acid absorbable plates and carbonated apatite bone cement

Cranial defect repair in the pediatric population requires a variety of special considerations. The pediatric skull has a dynamic nature that prohibits the use of rigid fixation, which is commonly applied in the adult population. A technique using a combination of polylactic acid plates and carbonated apatite bone cement has been devised by our group. Skull defects of varying sizes were repaired in 34 pediatric patients. Patients were examined on postoperative day 3 and at 3 months via three-dimensional computed tomography scans. Patients have been followed up to 60 months after surgery without complications or failures to date. This method benefits the pediatric patients undergoing cranioplasty by minimizing the insertion of long-term foreign bodies and allows the possibility for transformation of this construct into viable tissue.

Lumbar laminectomy for the resection of synovial cysts and coexisting lumbar spinal stenosis or degenerative spondylolisthesis: an outcome study

STUDY DESIGN

Surgeon- and patient-based (SF-36) outcome measures were used to assess the results of decompressive laminectomies for the excision of synovial cysts with coexistent lumbar spinal stenosis (45 patients) or for synovial cysts with coexistent lumbar stenosis and degenerative spondylolisthesis (35 patients).

OBJECTIVES

To evaluate the results following laminectomy and the excision of synovial cysts/stenosis with or without olisthy.

SUMMARY OF BACKGROUND DATA

SF-36 outcome studies evaluating these surgical results deserve further investigation.

METHODS

Before surgery, patients with synovial cysts/ stenosis (45 patients) or cysts/stenosis/degenerative spondylolisthesis (35 patients), respectively, exhibited low back pain (40 and 33 patients), radiculopathy (43 and 33 patients), and neurogenic claudication (41 and 26 patients). Surgery required average 3.8 and 3.5 level laminectomies, respectively, for patients with cysts/stenosis and cysts/stenosis and olisthy. Outcomes were assessed 2 years after surgery.

RESULTS

Five of 45 patients undergoing laminectomy alone for cysts/stenosis developed postoperative olisthy. Of 35 patients with cysts/stenosis and preoperative Grade 1 degenerative spondylolisthesis, olisthy increased after surgery to Grade 2 in 11 patients. Good/excellent results (58% and 63%) and SF-36 improvement on the Physical Function Scale (+44 and +38 points) were, respectively, documented for these two groups.

CONCLUSIONS

Using both surgeon and SF-36 outcome measures, 2 years following laminectomy for synovial cysts/lumbar stenosis with or without olisthy, patients exhibited a moderate degree of improvement. As synovial cysts reflect disruption of the facet joint and some degree of instability, primary fusion should be considered to improve operative results for patients in both categories.

The extraforaminal juxtafacet cyst as a rare cause of L5 radiculopathy: a case report

STUDY DESIGN

This is a report of a case.

OBJECTIVE

To document the clinical, radiographic, and histologic characteristics of a lumbar extraforaminal juxtafacet cyst.

SUMMARY OF BACKGROUND DATA

Spinal juxtafacet cysts develop most frequently at the dorsal aspect of the zygapophysial joint, sometimes in the posterolateral area of the canal. In one case, they have been described in the foraminal and extraforaminal region.

METHODS

Description of the case report.

RESULT

The authors report one case of a strictly extraforaminal juxtafacet cyst responsible for L5 sciatica.

CONCLUSIONS

Juxtafacet cysts of the spine represent an infrequent cause of sciatica, usually when they grow in the canal, or more exceptionally when they occupy the foraminal or extraforaminal areas.

Clinical outcome in cranioplasty: critical review in long-term follow-up

Various materials have been proposed for cranial reconstruction. Bone autograft and alloplasts such as polymethylmethacrylate (PMMA) and hydroxyapatite (HA) cement are most commonly used at the present time. Patients submitted for cranioplasty were evaluated. The prognostic factors influencing the results and the outcome were analyzed. Three hundred twelve patients who had 449 procedures performed by a single surgeon to reconstruct a calvarial deformity between 1981 and 2001 were studied. Post-tumor resection deformity was the main reason for cranioplasty (32.4%). Bone graft was the material of choice (69.5%). The main surgical site was the frontal bone (53.2%). Complications were observed in 23.6% of cases and were responsible for the least satisfactory results (P > 0.001), with infection and material exposure being the most critical complications. The eventual outcome was considered good in 91.8% of cases. The use of HA cement was associated with the worst results (P > 0.001). Bone grafts showed a high grade of partial resorption and required further surgery for correction. Multiple surgical procedures were correlated with a high rate of complications and an unsatisfactory outcome. Bone graft and PMMA are still the best materials in calvarial reconstruction. Even though HA cement is an osteoconductive material, it seems to induce what appears to be an immunoguided delayed inflammatory reaction that leads to thinning of the skin and exposure of the material, making secondary repair difficult. Before deciding which reconstructive option to use, a careful evaluation of the patient in terms of diagnosis, number of previous surgeries, and surgical site should be undertaken. If this is adopted, good results and a satisfactory outcome can be achieved on long-term follow-up.

Risk factors for spinal epidural hematoma after spinal surgery

STUDY DESIGN

A case-control retrospective analysis comparing patients who developed a postoperative spinal epidural hematoma with patients who did not develop this complication.

OBJECTIVES

To identify risk factors for the development of an epidural hematoma following spinal surgery.

SUMMARY OF BACKGROUND DATA

Neurologic deterioration following spinal surgery is a rare but devastating complication. Epidural hematomas should be suspected in the patient who demonstrates a new postoperative neurologic deficit. The risk factors that predispose a patient to a postoperative spinal epidural hematoma have not been identified.

METHODS

Patients who underwent spinal surgery at a single institution over a 10-year period were retrospectively reviewed. Twelve patients who demonstrated neurologic deterioration after surgery and required surgical decompression because of an epidural hematoma were identified. All cases involved lumber laminectomies. A total of 404 consecutive patients that underwent lumbar decompression and did not develop an epidural hematoma formed the control group. Factors postulated to increase the risk of postoperative spinal epidural hematoma were compared between the two groups using logistic regression.

RESULTS

Multilevel procedures (P = 0.037) and the presence of a preoperative coagulopathy (P < 0.001) were significant risk factors. Age, body mass index, perioperative durotomies, and postoperative drains were not statistically significant risk factors.

CONCLUSIONS

Patients who require multilevel lumbar procedures and/or have a preoperative coagulopathy are at a significantly higher risk for developing a postoperative epidural hematoma.

Lumbar facet joint synovial cyst: percutaneous treatment with steroid injections and distention--clinical and imaging follow-up in 12 patients

PURPOSE

To determine the imaging characteristics of lumbar facet joint synovial cysts after percutaneous treatment with steroid injections and distention of the cyst and to correlate these findings with the clinical outcome.

MATERIALS AND METHODS

Clinical outcome and imaging findings were retrospectively studied in 12 patients (four men, eight women) aged 45-79 years (mean, 60 years) with a symptomatic lumbar facet joint synovial cyst treated with percutaneous steroid injections. At varying times after the procedure, patients were contacted for clinical follow-up, and repeat imaging was performed to verify the status of the cyst.

RESULTS

Excellent pain relief was achieved in nine (75%) of 12 patients. At follow-up imaging, the cyst completely regressed in six (67%) of these nine patients, partially regressed in two (22%) patients, and was unchanged in one (11%) patient. One (8%) of the 12 patients had transient pain relief, with recurrence of symptoms at short intervals after each of three injections. No pain relief was achieved in two (17%) of 12 patients.

CONCLUSION

Image-guided percutaneous steroid injections are often effective in the treatment of lumbar facet joint synovial cysts and may result in complete regression of the cyst.