Biomedical subjects

Langston T Holly

Publications and source records attributed to Langston T Holly.

11 recordsLinked to original sources

PubMed2006

Treatment of lumbar synovial cysts using minimally invasive surgical techniques.

OBJECT: Lumbar synovial cysts are a potential cause of radiculopathy and back pain, and the definitive treatment is the complete excision of the cyst. This report summarizes the authors' preliminary clinical experience with the minimally invasive resection of lumbar synovial cysts. METHODS: Nineteen patients (nine men and 10 women) with symptomatic synovial cysts underwent minimally invasive resection. The mean patient age was 64 years of age (range 43-80 years). The presenting symptom was radiculopathy in 16 patients, low-back pain in two, and lower-extremity weakness in one. There were 16 cases of a cyst located at the L4-5 level, two at L3-4, and one at L5-S1. The mean cyst diameter was 13.7 mm (range 3-30 mm). The mean follow-up time was 16 months (range 4-29 months). Clinical outcomes were graded, based on the Macnab modified criteria, as excellent, good, fair, or poor. Eighteen patients (95% of cases) reported either excellent (10 patients) or good (eight patients) results, and a fair result was reported by one patient (5% of cases). The mean operative time was 158 minutes (range 75-270 minutes), and the average intraoperative blood loss was 31 ml (range 10-100 ml). Two patients had intraoperative dural tears that resulted in cerebrospinal fluid leaks that resolved following primary closure. CONCLUSIONS: Synovial cysts can be safely and effectively treated using minimally invasive surgical techniques. Long-term follow up is required to determine whether this approach results in less need for fusion than conventional surgical approaches.

Adult↗

PubMed2006

Minimally invasive transforaminal lumbar interbody fusion: indications, technique, and complications.

The authors provide an overview of the minimally invasive transforaminal lumbar interbody fusion (TLIF) procedure including indications, technique, and complications. This novel technique is a method of achieving circumferential lumbar fusion using a unilateral dorsal approach. Minimally invasive TLIF uses a tubular retractor that is inserted via a muscle-dilating exposure, thereby minimizing the approach-related morbidity. This procedure is ideal for refractory mechanical low-back and radicular pain associated with spondylolisthesis, degenerative disc disease, and recurrent disc herniation. The authors' clinical experience and review of the medical literature indicate that TLIF can be effectively and safely performed in a minimally invasive fashion.

Humans↗

PubMed2006

Percutaneous placement of posterior cervical screws using three-dimensional fluoroscopy.

STUDY DESIGN: The placement of percutaneous posterior cervical screws using three-dimensional fluoroscopic guidance was performed in intact human cadaver specimens. OBJECTIVES: To determine the accuracy and feasibility of placing entirely percutaneous posterior cervical screws using a novel form of spinal image guidance. SUMMARY OF BACKGROUND DATA: Conventional image guidance has been shown to increase the accuracy of many open cervical instrumentation procedures. There are presently no published studies reporting this novel method for guiding the percutaneous placement of posterior cervical screws. METHODS: An isocentric C-arm was used to obtain CT images of three intact cadaver specimens. A percutaneous dynamic reference array was attached to the C2 spinous process of each specimen. Light-emitting diodes attached to the C-arm were tracked with an electro-optical camera. The image data set was then transferred to the image-guided workstation, which performed an automated registration. Using the workstation, trajectories were planned for bilateral C1-C2 transarticular, C3-C6 lateral mass, and C7 pedicle screw placement. Through 1.5-cm incisions, a drill guide fitted with light-emitting diodes was used for sequential, image-guided drilling, tapping, and placement of cannulated 4.0 mm screws at each level. Postprocedure, thin-cut CT scanning was used to determine the accuracy of screw placement. RESULTS: A total of 41 of 42 percutaneous screws (97.6%) were accurately placed. All of the transarticular atlantoaxial and subaxial lateral mass screws showed no evidence of foramen transversarium, neural foramen, or facet joint violation. One of the C7 pedicle screws had a minor cortical wall violation. CONCLUSION: This study demonstrates the feasibility of placing percutaneous posterior cervical screws. Three-dimensional fluoroscopy appears to enable highly accurate, percutaneous three-dimensional cervical spine navigation.

Bone Screws↗

PubMed2006

Evaluation of registration techniques for spinal image guidance.

OBJECT: Paired point matching alone and paired point matching combined with surface matching are the two techniques used for the registration step in preoperative computerized tomography-based spinal image guidance. In the present study the authors sought to compare paired point-matching registration alone with paired point matching supplemented with surface matching to determine if the addition of surface matching improves navigational accuracy. METHODS: Pedicle screws were placed in three embalmed human cervicothoracic spinal specimens during image guidance to serve as a reference points. The specimens were then rescanned, and each level was registered using paired point matching alone and then by paired point supplemented with surface matching. Navigational accuracy was assessed by placing the stereotactic probe in the center of the screw head, and measuring the apparent distance between the screw head and probe on the computer monitor. Statistical analysis was used to compare the registration error and navigational error between the two techniques. Seventy-five screws were placed at 46 vertebral levels. The mean registration error for the paired point matching/surface matching technique (0.5 mm) was significantly lower (p < 0.001) than that of the paired point matching alone technique (1.2 mm); however, the intertechnique difference in navigational error was nearly equivalent (1.3 mm compared with 1.4 mm) and statistically insignificant (p > 0.05). CONCLUSIONS: Although the addition of surface matching to paired point registration significantly decreased the mean registration error, the actual navigational accuracy between the two techniques was equivalent when easily distinguishable points were meticulously selected. The use of paired point matching alone did not compromise the accuracy of navigation and is likely to result in decreased operating time.

Bone Screws↗

PubMed2006

Syringomyelia associated with intradural arachnoid cysts.

OBJECT: Intradural arachnoid cysts are relatively uncommon pouches of cerebrospinal fluid (CSF) found within the subarachnoid space. The authors present a series of eight symptomatic patients in whom syrinx cavities were associated with arachnoid cysts, and they discuss treatment strategies for this entity. METHODS: The population comprised eight men whose mean age was 50 years (range 35-81 years). All patients experienced gait difficulty, and it was the chief complaint in seven; arm pain was the primary complaint in one. No patient had a history of spinal trauma, meningitis, or previous spinal surgery at the level of the syrinx cavity or arachnoid cyst. In each patient imaging revealed a syrinx cavity affecting two to 10 vertebral levels. Posterior thoracic arachnoid cysts were found in proximity to the syrinx cavity in each case. There was no evidence of cavity enhancement, Chiari malformation, tethered cord, or hydrocephalus. All patients underwent thoracic laminectomy and resection of the arachnoid cyst wall, and postoperative neurological improvement was documented in each case. The mean follow-up duration was 19 months (range 4-37 months). Follow-up magnetic resonance imaging demonstrated the disappearance of the arachnoid cyst and a significant decrease in syrinx cavity size in each patient. CONCLUSIONS: Spinal arachnoid cysts can be associated with syringomyelia, likely due to alterations in normal CSF dynamics. In symptomatic patients these cysts should be resected and the normal CSF flow restored. The results of the present series indicate that neurological improvement and reduction in syrinx cavity size can be achieved in patients with syringomyelia associated with intradural arachnoid cysts.

Adult↗

PubMed2005

Minimally invasive transforaminal lumbar interbody fusion (TLIF): technical feasibility and initial results.

Forty-nine patients underwent minimally invasive transforaminal lumbar interbody fusion (TLIF) from October 2001 to August 2002 (minimum 18-month follow-up). The diagnosis was degenerative disc disease with herniated nucleus pulposus (HNP) in 26, spondylolisthesis in 22, and a Chance-type seatbelt fracture in 1. The majority of cases (n = 45) were at L4-L5 or L5-S1. A paramedian, muscle-sparing approach was performed through a tubular retractor docked unilaterally on the facet joint. A total facetectomy was then conducted, exposing the disc space. Discectomy and endplate preparation were completed through the tube using customized surgical instruments. Structural support was achieved with allograft bone or interbody cages. Bone grafting was done with local autologous or allograft bone, augmented with recombinant human bone morphogenetic protein-2 in some cases. Bilateral percutaneous pedicle screw-rod placement was accomplished with the Sextant system. There were no conversions to open surgery. Operative time averaged 240 minutes. Estimated blood loss averaged 140 mL. Mean length of hospital stay was 1.9 days. All patients presenting with preoperative radiculopathy (n = 45) had resolution of symptoms postoperatively. Complications included two instances of screw malposition requiring screw repositioning and two cases of new radiculopathy postoperatively (one from graft dislodgement, the other from contralateral neuroforaminal stenosis). Narcotic use was discontinued 2-4 weeks postoperatively. Improvements in average Visual Analogue Pain Scale and Oswestry Disability Index (preoperative to last follow-up) scores were 7.2-2.1 and 46-14, respectively. At last follow-up, all patients had solid fusions by radiographic criteria. Results of this study indicate that minimally invasive TLIF is feasible and offers several potential advantages over traditional open techniques.

Adult↗

PubMed2003

Minimally invasive lumbar fusion.

STUDY DESIGN: Review article. OBJECTIVES: To provide an overview of current techniques for minimally invasive lumbar fusion. SUMMARY OF BACKGROUND DATA: Minimally invasive techniques have revolutionized the management of pathologic conditions in various surgical disciplines. Although these same principles have been used in the treatment of lumbar disc disease for many years, minimally invasive lumbar fusion procedures have only recently been developed. The goals of these procedures are to reduce the approach-related morbidity associated with traditional lumbar fusion, yet allow the surgery to be performed in an effective and safe manner. METHODS: The authors' clinical experience with minimally invasive lumbar fusion was reviewed, and the pertinent literature was surveyed. RESULTS: Minimally invasive approaches have been developed for common lumbar procedures such as anterior and posterior interbody fusion, posterolateral onlay fusion, and internal fixation. As with all new surgical techniques, minimally invasive lumbar fusion has a learning curve. As well, there are benefits and disadvantages associated with each technique. However, because these techniques are new and evolving, evidence to support their potential benefits is largely anecdotal. Additionally, there are few long-term studies to document clinical outcomes. CONCLUSIONS: Preliminary clinical results suggest that minimally invasive lumbar fusion will have a beneficial impact on the care of patients with spinal disorders. Outcome studies with long-term follow-up will be necessary to validate its success and allow minimally invasive lumbar fusion to become more widely accepted.

Animals↗

PubMed2003

Intraoperative spinal navigation.

STUDY DESIGN: Review article. OBJECTIVES: To provide a detailed overview of current methods for intraoperative spinal navigation using image-guided surgical technology. SUMMARY OF BACKGROUND DATA: The development of novel intraoperative navigational techniques has been an important advancement in the field of spine surgery. These techniques, commonly referred to as image-guided surgery (IGS), provide simultaneous, multiplanar views of spinal anatomy. They can be used for detailed preoperative planning and allow the spinal surgeon to track the position of surgical instruments in real time. IGS technology can increase the accuracy of spinal instrumentation procedures and improve patient safety. METHODS: The relevant medical literature was reviewed, as was the authors' clinical and laboratory experience with intraoperative spinal navigation. RESULTS: Image-guided spinal instrumentation procedures in the cervical, thoracic, and lumbar spine have lower rates of screw misplacement than do those performed without image guidance. In a typical IGS spinal procedure, surgical instruments are tracked in the operating room, and their positions are superimposed onto preoperatively acquired computed tomography scans (CT-based image guidance) or intraoperatively acquired fluoroscopic images (virtual fluoroscopy). A new development, the combination of isocentric C-arm fluoroscopy with computer-assisted image guidance, allows the C-arm to create intraoperative CT images that can be used for image-guided navigation without the need for a surgeon-dependent registration step. Each of these technologies has distinct advantages and limitations. CONCLUSIONS: Intraoperative spinal navigation has advanced rapidly in recent years, beneficially affecting a variety of surgical procedures. Future technological developments will widen its clinical application and minimize its shortcomings.

Adult↗

PubMed2003

Three-dimensional fluoroscopy-guided percutaneous thoracolumbar pedicle screw placement. Technical note.

The authors sought to evaluate the feasibility and accuracy of three-dimensional (3D) fluoroscopic guidance for percutaneous placement of thoracic and lumbar pedicle screws in three cadaveric specimens. After attaching a percutaneous dynamic reference array to the surgical anatomy, an isocentric C-arm fluoroscope was used to obtain images of the region of interest. Light-emitting diodes attached to the C-arm unit were tracked using an electrooptical camera. The image data set was transferred to the image-guided workstation, which performed an automated registration. Using the workstation display, pedicle screw trajectories were planned. An image-guided drill guide was passed through a stab incision, and this was followed by sequential image-guided pedicle drilling, tapping, and screw placement. Pedicle screws of various diameters (range 4-6.5 mm) were placed in all pedicles greater than 4 mm in diameter. Postoperatively, thin-cut computerized tomography scans were obtained to determine the accuracy of screw placement. Eighty-nine (94.7%) of 94 percutaneous screws were placed completely within the cortical pedicle margins, including all 30 lumbar screws (100%) and 59 (92%) of 64 thoracic screws. The mean diameter of all thoracic pedicles was 6 mm (range 2.9-11 mm); the mean diameter of the five pedicles in which wall violations occurred was 4.6 mm (range 4.1-6.3 mm). Two of the violations were less than 2 mm beyond the cortex; the others were between 2 and 3 mm. Coupled with an image guidance system, 3D fluoroscopy allows highly accurate spinal navigation. Results of this study suggest that this technology will facilitate the application of minimally invasive techniques to the field of spine surgery.

Bone Screws↗

PubMed2002

Cervical spine trauma associated with moderate and severe head injury: incidence, risk factors, and injury characteristics.

OBJECT: Diagnosing and managing cervical spine trauma in head-injured patients is problematic due to an altered level of consciousness in such individuals. The reported incidence of cervical spine trauma in head-injured patients has generally ranged from 4 to 8%. In this retrospective study the authors sought to define the incidence of cervical injury in association with moderate or severe brain injury, emphasizing the identification of high-risk patients. METHODS: The study included 447 consecutive moderately (209 cases) or severely (238 cases) head injured patients who underwent evaluation at two Level 1 trauma centers over a 40-month period. Of the 447 patients, 24 (5.4%) suffered a cervical spine injury (17 men and seven women; mean age 39 years; median Glasgow Coma Scale [GCS] score of 6, range 3-14). Of these 24 patients, 14 (58.3%) sustained spinal cord injuries (SCIs), 14 sustained injuries in the occiput-C3 region, and 10 underwent a stabilization procedure. Of the 14 patients with SCIs, nine experienced an early hypotensive and/or hypoxic insult. Regarding the mechanism of injury, cervical injuries occurred in 21 (8.2%) of 256 patients involved in motor vehicle accidents (MVAs), either as passengers or pedestrians, compared with three (1.6%) of 191 patients with non-MVA-associated trauma (p < 0.01). In the subset of 131 MVA passengers, 13 (9.9%) sustained cervical injuries. Patients with an initial GCS score less than or equal to 8 were more likely to sustain a cervical injury than those with a score higher than 8 (odds ratio [OR] 2.77, 95% confidence interval [CI] = 1.11-7.73) and were more likely to sustain a cervical SCI (OR 5.5, 95% CI 1.22-24.85). At 6 months or more postinjury, functional neurological recovery had occurred in nine patients (37.5%) and eight (33.3%) had died. CONCLUSIONS: Head-injured patients sustaining MVA-related trauma and those with an initial GCS score less than or equal to 8 are at highest risk for concomitant cervical spine injury. A disproportionate number of these patients sustain high cervical injuries, the majority of which are mechanically unstable and involve an SCI. The development of safer and more rapid means of determining cervical spine integrity should remain a high priority in the care of head-injured patients.

Adolescent↗

PubMed2002

Slitlike syrinx cavities: a persistent central canal.

OBJECT: The authors review their experience in the diagnosis and management of 32 patients with slitlike syrinx cavities. METHODS: There were 18 men and 14 women with a mean age of 40 years. Presenting symptoms that prompted magnetic resonance (MR) imaging evaluation were mechanical spinal pain (13 patients), radicular pain (seven patients), paresthesia (six patients), numbness (five patients), and muscle spasm (one patient). In 12 patients neurological examination demonstrated normal status, and in the remainder only minimal sensory or motor abnormalities were found. The mean diameter of the syrinx cavity was 2 mm (range 1-5 mm), and on average it covered three vertebral levels. The cavities were limited to the cervical region in 16 patients, the thoracic in 12, and both regions in four patients. The mean follow-up time for changes in clinical condition and repeated MR imaging features were 38 and 32 months, respectively. Thirty-one patients were treated nonoperatively, and one was treated surgically. During the follow-up period clinical improvement was documented in six patients, worsened status in seven, and no change was demonstrated in the clinical status of 19 patients. None of the syrinx cavities changed in size. In 16 patients medical workup revealed alternative diagnoses that were determined to be the true causes of each patient's symptoms. CONCLUSIONS: Slitlike cavities likely do not represent true syringomyelia but rather remnants of the central canal detected in a small percentage of adults. Review of the authors' experience indicates that these cavities are asymptomatic and are unlikely to change in size. They can be considered an incidental finding, and in many of these patients another condition explaining the patient's symptoms may be found.

Adolescent↗