Biomedical subjects

Fred H Geisler

Publications and source records attributed to Fred H Geisler.

13 recordsLinked to original sources

PubMed2006

Evaluation of surgical volume and the early experience with lumbar total disc replacement as part of the investigational device exemption study of the Charité Artificial Disc.

STUDY DESIGN: A prospective, randomized, multicenter, Food and Drug Administration regulated Investigational Device Exemption (IDE) clinical trial. OBJECTIVES: To discern whether there is a correlation between surgical volume and clinical outcomes, as well as the complication rate and perioperative data points, for lumbar total disc replacement. To examine the early experience for lumbar total disc replacement as part of an IDE study. SUMMARY OF BACKGROUND DATA: To our knowledge, an analysis of the effect of surgical volume has not been performed for any spine surgical procedure. Prior reports of the early experience with lumbar total disc replacement consist of retrospective reviews with nonspecific indications. METHODS: An analysis was performed of the Food and Drug Administration IDE Study of the Charité Artificial Disc (DePuy Spine, Inc., Raynham, MA). Patients enrolled in the control group were omitted from the analysis. Up to 5 nonrandomized cases (representing the early experience) were performed at each site before beginning the randomized arm of the study. There were 3 comparisons performed: nonrandomized cases (71) versus randomized cases (205); randomized cases performed by high-enrolling surgeons versus low-enrolling surgeons; and randomized cases at high-volume institutions versus low-volume institutions. RESULTS: The high-enrolling groups had a significantly lower mean hospital stay and operating time compared to the low-enrolling groups (P < 0.05). High-enrolling surgeons and institutions showed significantly shorter operating times, length of hospital stay, and complication rates. High-enrolling surgeons had significantly fewer device failures and cases of neurologic deterioration. Mean operating time and hospital stay were significantly lower in the randomized group (P < 0.05) compared to the nonrandomized group. Blood loss and approach-related complications were similar between the 2 groups. Device failure requiring removal was 4.2% in the nonrandomized group and 1.5% in the randomized group. CONCLUSIONS: Surgeons and institutions with a high volume of lumbar total disc replacement cases have a reduction in key perioperative and postoperative parameters that provide a clinical and/or economic benefit. Surgeons may expect longer hospital stays, higher blood loss, and a higher rate of certain complications in their early experience with total disc replacement procedures, but there was no effect on clinical outcomes.

Adolescent↗

PubMed2006

Revisability of the CHARITE artificial disc replacement: analysis of 688 patients enrolled in the U.S. IDE study of the CHARITE Artificial Disc.

STUDY DESIGN: A prospective, randomized, multicenter, FDA-regulated Investigational Device Exemption clinical trial. OBJECTIVES: To analyze the incidence of, and reasons for, reoperation in all patients (treatment and control) enrolled in the IDE study. SUMMARY OF BACKGROUND DATA: This is the first report of the incidence and nature of reoperations following lumbar TDR as part of a controlled, prospective, multicenter trial. METHODS: A total of 688 patients meeting the inclusion and exclusion criteria were enrolled in one of three arms of the study at 14 centers across the United States. This cohort includes 71 nonrandomized cases, 205 randomized cases, and 313 continued access cases, all receiving the CHARITE Artificial Disc, as well as 99 randomized cases in the control group (ALIF with threaded fusion cages and autograft). A detailed analysis was performed of clinical chart notes, operative notes, and adverse event reports for all patients requiring reoperation following their index surgery. RESULTS: Of the 589 patients with TDR, 52 (8.8%) required reoperation. Of the 99 patients with lumbar fusion, 10 (10.1%) required reoperation, and an additional 2 required surgery for adjacent level disease (P = 0.7401). There were 24 TDR patients who underwent a repeated anterior retroperitoneal approach, with 22 (91.7%) having had a successful removal of the prosthesis. Seven of the 24 TDR prostheses requiring removal were revised to another CHARITE Artificial Disc. The mean time to reoperation in all patients was 9.7 months. A total of 29 patients (4.9%) in the TDR group required posterior instrumentation and fusion as did 10 (10.1%) in the control group (P = 0.0562). At 2 years or more follow-up, 93.9%(553/589 = 93.9%) of patients receiving TDR with the CHARITE Artificial Disc had a successfully functioning prosthesis with a mean of over 7 degrees of flexion-extension mobility. CONCLUSIONS: Lumbar TDR with the CHARITE Artificial Disc did not preclude any further procedures at the index level during primary insertion, with nearly one third being revisable to a new motion-preserving prosthesis and just over two thirds being successfully converted to ALIF and/ or posterior pedicle screw arthrodesis, the original alternative procedure.

Adult↗

PubMed2005

A prospective, randomized, multicenter Food and Drug Administration investigational device exemptions study of lumbar total disc replacement with the CHARITE artificial disc versus lumbar fusion: part I: evaluation of clinical outcomes.

STUDY DESIGN: A prospective, randomized, multicenter, Food and Drug Administration-regulated Investigational Device Exemption clinical trial. OBJECTIVES: The purpose of this study was to compare the safety and effectiveness of lumbar total disc replacement, using the CHARITE artificial disc (DePuy Spine, Raynham, MA), with anterior lumbar interbody fusion, for the treatment of single-level degenerative disc disease from L4-S1 unresponsive to nonoperative treatment. SUMMARY OF BACKGROUND DATA: Reported results of lumbar total disc replacement have been favorable, but studies have been limited to retrospective case series and/or small sample sizes. METHODS: Three hundred four (304) patients were enrolled in the study at 14 centers across the United States and randomized in a 2:1 ratio to treatment with the CHARITE artificial disc or the control group, instrumented anterior lumbar interbody fusion. Data were collected pre- and perioperatively at 6 weeks and at 3, 6, 12, and 24 months following surgery. The key clinical outcome measures were a Visual Analog Scale assessing back pain, the Oswestry Disability Index questionnaire, and the SF-36 Health Survey. RESULTS: Patients in both groups improved significantly following surgery. Patients in the CHARITE artificial disc group recovered faster than patients in the control group. Patients in the CHARITE artificial disc group had lower levels of disability at every time interval from 6 weeks to 24 months, compared with the control group, with statistically lower pain and disability scores at all but the 24 month follow-up (P < 0.05). At the 24-month follow-up period, a significantly greater percentage of patients in the CHARITE artificial disc group expressed satisfaction with their treatment and would have the same treatment again, compared with the fusion group (P < 0.05). The hospital stay was significantly shorter in the CHARITE artificial disc group (P < 0.05). The complication rate was similar between both groups. CONCLUSIONS: This prospective, randomized, multicenter study demonstrated that quantitative clinical outcome measures following lumbar total disc replacement with the CHARITE artificial disc are at least equivalent to clinical outcomes with anterior lumbar interbody fusion. These results support earlier reports in the literature that total disc replacement with the CHARITE artificial disc is a safe and effective alternative to fusion for the surgical treatment of symptomatic disc degeneration in properly indicated patients. The CHARITE artificial disc group demonstrated statistically significant superiority in two major economic areas, a 1-day shorter hospitalization, and a lower rate of reoperations (5.4% compared with 9.1%). At 24 months, the investigational group had a significantly higher rate of satisfaction (73.7%) than the 53.1% rate of satisfaction in the control group (P = 0.0011). This prospective randomized multicenter study also demonstrated an increase in employment of 9.1% in the investigational group and 7.2% in the control group.

Adult↗

PubMed2005

Prognostic value of pinprick preservation in motor complete, sensory incomplete spinal cord injury.

OBJECTIVE: To assess sacral and lower-extremity pinprick preservation as prognostic indicators for ambulation in motor complete, sensory incomplete spinal cord injury (SCI). DESIGN: Retrospective analysis. SETTING: Twenty-eight tertiary care centers in the United States and Canada. PARTICIPANTS: Subjects (N=131; mean age, 31.6y) with motor complete, sensory incomplete SCI. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Ambulation at 26 and 52 weeks postinjury (modified Benzel scale). RESULTS: A higher percentage of subjects with sacral pinprick preservation at baseline were ambulating at 26 (39.4% vs 28.3%) and 52 weeks (53.6% vs 41.5%). This finding did not reach statistical significance. The presence of sacral pinprick preservation at 4 weeks postinjury was significant for predicting ambulation at 52 weeks postinjury (36.0% vs 4.4%, P =.011) and approached significance at 26 weeks (15.2% vs 0.0%, P =.056). Significant differences in ambulation rates were also observed between subjects, based on the presence of baseline lower-extremity pinprick preservation (>/=50% of lower-extremity L2-S1 dermatomes) at both 26 (50.0% vs 28.8%, P =.048) and 52 weeks (66.7% vs 40.3%, P =.023) after injury. CONCLUSIONS: Baseline lower-extremity pinprick preservation and sacral pinprick preservation at 4 weeks postinjury are associated with an improved prognosis for ambulation.

Adult↗

PubMed2005

Surgical technique of lumbar artificial disc replacement with the Charité artificial disc.

Lumbar artificial disc technology has been commercially available outside the United States for nearly 2 decades. With the Food and Drug Administration approval of the Charité Artificial Disc in October 2004, an entirely new spinal surgeon population will be able to offer this technology to their patients as a treatment option. As with other techniques in spinal surgery, indications for lumbar total disc replacement are paramount to the success of the procedure. The correct surgical technique is also important to a successful outcome. This article describes the technique for placement of the Charité Artificial Disc in indicated patients. The technique is similar to that of an anterior lumbar interbody fusion procedure, but many differences between the techniques make lumbar total disc replacement a unique procedure in the spinal surgeon's armamentarium. Although this article is thorough in its description of the surgical technique for total disc replacement with the Charité Artificial Disc, it should not be used as a substitute for company-sponsored training.

Device Approval↗

PubMed2005

Bone graft extenders.

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Bone Demineralization Technique↗

PubMed2004

A new computer-aided technique for analysis of lateral cervical radiographs in postoperative patients with degenerative disease.

STUDY DESIGN: Radiographs were measured by four independent observers and remeasured by three of the observers. OBJECTIVES: To assess the reliability of a new computer-aided measurement technique. SUMMARY OF BACKGROUND DATA: Many studies have reported sagittal-plane distance and angle measurements in the cervical spine. Common measurement methods involve manual line drawing on lateral radiographs with manual or computer-aided distance and angle computation. In patients with anterior cervical fusion, changes in bony geometry could present difficulties for many existing methods. METHODS: Digitized lateral cervical radiographs are imported into a graphics software package. Outlines of the vertebral bodies and spinous processes are traced on the best-quality film and transformed to match the bony geometry on each remaining radiograph from the same patient. Intervertebral distance and angulation are calculated from centers of mass of the outlined elements. Segmental measurements were collected for 27 lateral radiographs from nine patients with anterior cervical discectomy and fusion. Intraclass and interclass correlation coefficients were calculated and used to compute standard errors of measurement. RESULTS: High intraclass and interclass correlations (ICCs) and low measurement errors were calculated for both distance and angle measurements. Intraexaminer mean ICCs were 0.92 for interbody distance and 0.93 for segmental angle, with standard errors of measurement (SEMs) of 3.26% interbody distance (approximately 0.65 mm) and 1.20 degrees sagittal-plane rotation. Mean interexaminer ICCs were 0.91 for interbody distance and 0.86 for segmental angle, with SEMs of 3.58% interbody distance (approximately 0.72 mm) and 1.77 degrees sagittal-plane rotation. CONCLUSIONS: The measurement method is reliable for both interbody distance and segmental angles within and among examiners. Whereas many existing measurement methods require normal radiographs to locate specific anatomic points, given intact spinous processes, the present method functions even with various radiographic abnormalities and in the presence of surgical decompression, degenerative disease, and cervical hardware. Because it does not rely on specific anatomic points, the present method is robust with respect to changes in the bony anatomy over time.

Cervical Vertebrae↗

PubMed2004

Geometric results of anterior cervical plate stabilization in degenerative disease.

STUDY DESIGN: Consecutive case retrospective computerized analysis of lateral radiographs. OBJECTIVES: To investigate the time evolution of the geometry of anterior cervical discectomy and fusion using a new computer-aided measurement technique. SUMMARY OF BACKGROUND DATA: Prior clinical studies have reported benefits and complications of anterior cervical plate stabilization, but have not comprehensively described changes in sagittal geometry following arthrodesis and plating. High fusion success rates have been reported for single-level discectomy and fusion, whereas multilevel procedures have demonstrated lower clinical success rates with increased hardware failure and pseudarthrosis rates. METHODS: Sagittal alignment data were collected from lateral radiographs of 51 patients with 52 operations for single- or multiple-level anterior cervical discectomy and fusion, both with and without anterior cervical plate stabilization. Intervertebral angulation and separation at the operated segments before surgery, immediately after surgery, and at long-term follow-up were compared using a computer-aided technique. RESULTS: Single-level anterior cervical discectomy and fusion with plate stabilization lost 0.9 degrees of the operatively obtained lordosis after surgery compared to 7.5 degrees for single-level fusions with bone alone (P = 0.0001). In multilevel anterior cervical discectomy and fusion, the bottommost level of the anterior cervical discectomy and fusion construct was much more prone to collapse than the remaining levels (mean bottom-level loss of 4.0 degrees vs. mean 0.2 degrees increase at the remaining levels, P < 0.0001). CONCLUSIONS: Anterior cervical plate stabilization helps maintain operatively obtained segmental distraction and lordosis following anterior cervical discectomy and fusion. In multilevel procedures, this study found that postoperative collapse is largely localized to the bottommost level, where hardware failure and pseudarthrosis have been observed most often by others.

Adult↗

PubMed2004

Two-year fusion rate equivalency between Grafton DBM gel and autograft in posterolateral spine fusion: a prospective controlled trial employing a side-by-side comparison in the same patient.

STUDY DESIGN: Multicenter, prospective equivalency trial with each patient serving as his/her own control. OBJECTIVES: To compare the effectiveness of a Grafton DBM gel composite with iliac crest autograft in posterolateral spine fusion. SUMMARY OF BACKGROUND DATA: While autograft remains the preferred graft material to facilitate spine fusion, the supply is limited and harvesting produces undesirable clinical consequences. METHODS: A total of 120 patients underwent posterolateral spine fusion with pedicle screw fixation and bone grafting. Iliac crest autograft was implanted on one side of the spine and a Grafton DBM/autograft composite was implanted on the contralateral side in the same patient. An independent, blinded reviewer evaluated anteroposterior and lateral flexion-extension radiographs. The fusion mass lateral to the instrumentation on each side was judged fused or not, and the mineralization of the graft was rated absent, mild, moderate, or extensive. The degree of correspondence in outcomes between sides was estimated by computing the percentage agreement and kappa statistic. RESULTS: Nearly 70% of patients (81 of 120) provided complete 24-month radiographic studies. The bone graft mass was fused in 42 cases (52%) on the Grafton DBMside and in 44 cases (54%) on the autograft side. The overall percentage agreement for fusion status between sides was approximately 75% (61 of 81), indicating moderately strong statistical correspondence (kappa = 0.51, P < 0.0001). Bone mineralization ratings also were similar between treated sides. Perfect agreement was realized in almost 60% of patients (48 of 81) with moderate statistical correspondence (weighted kappa = 0.54, P < 0.0001). CONCLUSIONS: Grafton DBM can extend a smaller quantity of autograft than is normally required to achieve a solid spinal arthrodesis. Consequently, a reduced amount of harvested autograft may be required, potentially diminishing the risk and severity of donor site complications.

Bone Matrix↗

PubMed2004

Neurological complications of lumbar artificial disc replacement and comparison of clinical results with those related to lumbar arthrodesis in the literature: results of a multicenter, prospective, randomized investigational device exemption study of Charité intervertebral disc. Invited submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2004.

OBJECT: Arthrodesis is the gold standard for surgical treatment of lumbar degenerative disc disease (DDD). Solid fusion, however, can cause stress and increased motion in the segments adjacent to the fused level. This may initiate and/or accelerate the adjacent-segment disease process. Artificial discs are designed to restore and maintain normal motion of the lumbar intervertebral segment. Restoring and maintaining normal motion of the segment reduces stresses and loads on adjacent level segments. A US Food and Drug Administration Investigational Device Exemptions multicentered study of the Charité artificial disc was completed. The control group consisted of individuals who underwent anterior lumbar interbody fusion involving BAK cages and iliac crest bone graft. This is the first report of Class I data in which a lumbar artificial disc is compared with lumbar fusion. METHODS: Of 304 individuals enrolled in the study, 205 were randomized to the Charité disc-treated group and 99 to the BAK fusion-treated (control) group. Neurological status was equivalent between the two groups at 6, 12, and 24 months postoperatively. The number of patients with major, minor, or other neurological complications was equivalent. There was a greater incidence of both major and minor complications in the BAK fusion group at 0 to 42 days postoperatively. Compared with data reported in the lumbar fusion literature, the Charité disc-treated patients had equivalent or better mean changes in visual analog scale and Oswestry Disability Index scores. CONCLUSIONS: The Charité artificial disc is safe and effective for the treatment of single-level lumbar DDD, resulting in no higher incidence of neurological complications compared with BAK-assisted fusion and leading to equivalent or better outcomes compared with those obtained in the control group and those reported in the lumbar fusion literature.

Biomechanical Phenomena↗

PubMed2002

Spinal cord injury.

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Clinical Trials as Topic↗

PubMed2002

Anterior access to the lumbar spine: laparoscopic versus open.

The purpose of this study is to investigate the potential advantages and complications of a minimally invasive laparoscopic approach for anterior spinal exposure as compared with the open technique and to quantify differences in operative time, blood loss, transfusion requirements, analgesia, and morbidity. A retrospective review was performed on all patients undergoing access for anterior spinal procedures. Demographics, operation-related variables, complications, and estimated cost were analyzed. Categorical data were analyzed using the Fisher's exact test and continuous variables were analyzed with the Mann-Whitney U test. We performed a total of 65 anterior spinal access procedures between February 1997 and April 2001 at our institution. Forty-five operations were performed at the L5-S1 level: 31 using transperitoneal laparoscopic techniques and 14 using an open minilaparotomy. Mean follow-up was 12 months (range 1-50). No significant differences between the groups were found when comparing analgesia requirements, time to resumption of oral intake, length of hospitalization, and complication rates. Statistical analysis showed that laparoscopic procedures were associated with shorter operating room times (P = 0.08) and less intraoperative blood loss (P = 0.029). The laparoscopic approach was estimated to cost $1,374 more than the open technique. Transperitoneal laparoscopic techniques for anterior spinal exposure are comparable to the standard open approach and offer no substantive advantages. The overall cost of laparoscopic spinal surgery is higher compared with conventional open procedures.

Adult↗

PubMedDate not supplied

Injury severity as primary predictor of outcome in acute spinal cord injury: retrospective results from a large multicenter clinical trial.

BACKGROUND CONTEXT: The prognostic value of injury severity and of anatomical region in acute spinal cord injury is strong, making it hard to evaluate other indicators or assess improvement without considering them. PURPOSE: This study documents issues and suggests a practical way to stratify. STUDY DESIGN/SETTING: Retrospective analysis of data prospectively collected for the multicenter trial of GM-1. PATIENT SAMPLE: A total of 760 patients were recruited at 28 centers in North America. Injuries were rostral to T10 and left at least one leg with an American Spinal Injury Association (ASIA) motor score less than 15 of 25. Patients were assessed at baseline using the ASIA Impairment Scale (AIS): Grade A, Grade B, and Grades C and D (combined). They were divided by injury region: cervical or thoracic. OUTCOME MEASURES: The endpoint was marked recovery (MR), defined as improvement of at least two grades from AIS at baseline to Modified Benzel Scale at Week 26. Other endpoints were changes in ASIA Motor, in light touch, and in pin prick scores. METHODS: Data were verified onsite by a central team of monitors, the database was checked and standard statistical techniques were applied. RESULTS: Recruitment was uneven. In 760 patients, 579 injuries were cervical, and 482 were complete. There were few incomplete thoracic injuries. The cervical group had more MR than the thoracic group (37.2% vs 15.9%, p< .0001). AIS Groups C and D had (p< .0001) more MR (84.0%) than Group B (46.6%), which recovered more than Group A (12.8%). The cervical group had an advantage in MR because it had more patients with AIS B, and still more AIS C and D. Within AIS Group A, the cervical subgroup had (p< .02) higher MR (15.5%) than the thoracic one (7.0%), but MR was nearly equal in the B and CD groups. This suggested a new stratification variable, "injury region/severity," to distinguish cervical (n=332, MR=15.5%) and thoracic (n=150, MR=7.0%) injuries within AIS A, but not in AIS B (n=131, MR=46.6%) or AIS CD (n=147, MR=84.1%). This variable is a significant predictor of MR (p< .0001). CONCLUSIONS: AIS severity was the strongest predictor. Anatomical region was also strong but confounded with the severity effect, because the cervicals had fewer complete injuries, and because the cervical complete group did better than thoracic complete. The injury region/severity variable keeps the strong prognostic value of using both region and severity, but is simpler and more statistically economical.

Acute Disease↗