Biomedical subjects

Donna D Ohnmeiss

Publications and source records attributed to Donna D Ohnmeiss.

12 recordsLinked to original sources

PubMed2006

Failed back surgery syndrome: diagnostic evaluation.

Failed back surgery syndrome is a common problem with enormous costs to patients, insurers, and society. The etiology of failed back surgery can be poor patient selection, incorrect diagnosis, suboptimal selection of surgery, poor technique, failure to achieve surgical goals, and/or recurrent pathology. Successful intervention in this difficult patient population requires a detailed history, precise physical examination, and carefully chosen diagnostic tests. The diagnostic evaluation should endeavor to accurately identify symptoms, rule out extraspinal causes, identify a specific spinal etiology, and assess the psychological state of the patient. Only after these factors have been assessed can further treatment be planned.

Back Pain↗

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↗

PubMed2003

Case report: intraoperative left common iliac occlusion in a scheduled 360-degree spinal fusion.

STUDY DESIGN: This is a case report of a left common iliac artery occlusion identified as an intraoperative complication during a planned (combined anterior interbody and posterior fusion) 360 degrees spinal fusion. OBJECTIVE: The purpose of this report was to document the occurrence of this rare complication during a planned 360 degrees fusion and to increase the awareness of this potential intraoperative vascular complication. SUMMARY OF BACKGROUND DATA: Several cases of left iliac artery occlusion after anterior spinal surgery have been reported, but there has been no reported case of intraoperative iliac artery occlusion identified during a planned 360 degrees spinal fusion. METHODS: The patient was a 46-year-old woman with chronic low and mid back pain and left leg pain for several years. She was a 2-pack-a-day cigarette smoker for 30 years. She was diagnosed with internal disc disruption at L3-L4 and L4-L5, unresponsive to nonoperative treatment, and was scheduled for a 360 degrees spinal fusion. During the anterior procedure, the left iliac vessels were retracted with a Wiley retractor during the discectomy and fusion. It was noted that there was no pulse in the left common iliac artery as the anterior procedure neared completion. Intraoperative Doppler showed the left iliac artery was occluded, and a left iliac endarterectomy and thrombectomy were performed immediately. RESULTS: A significant occlusive plaque was separated distally and transected in a smooth fashion, and fresh thrombus was also removed. The procedure was successfully accomplished without any further complication with excellent restoration of arterial blood flow to the left lower extremity. Doppler study showed good triphasic flow in the iliac artery and all its branches. Because of the arterial repair, the posterior portion of the surgery was not undertaken at that time and was performed 2 weeks later. CONCLUSIONS: Early recognition and appropriate treatment can prevent serious sequelae. Great care and observation should be given to the patients before surgery, intraoperatively, as well as after surgery.

Arterial Occlusive Diseases↗

PubMed2003

Intervertebral disc prostheses.

STUDY DESIGN: This article is based on a comprehensive review of the literature related to intervertebral disc prostheses. OBJECTIVE: To compile an overview of the results and complications related to various types of lumbar and cervical disc replacements. SUMMARY OF BACKGROUND DATA: A functional disc prosthesis has been sought since the 1950s. Although there were a few early attempts, disc replacement did not become a viable therapy until the late 1980s. Devices that were used in Europe at that time are now being evaluated in the United States in clinical trials. Cervical disc replacements are currently in the early stages of development and evaluation. METHODS: A thorough literature search was conducted to identify articles published on intervertebral disc prostheses. Proceedings from conferences were reviewed as well. Articles were classified by topics, including lumbar total disc replacement, disc nucleus replacement, and cervical disc replacement. RESULTS: Results of total disc replacement are favorable, with 63-85% of patients having a good outcome. As with any procedure, issues related to patient selection, operative technique, and device size selection were learned from the early experiences with these devices. There has been only one disc nucleus replacement used in an appreciable number of patients. This has yielded good results, but there have been problems related to device displacement. There are increasing reports on the use of cervical disc replacements, but they are still in the early evaluation phases. However, as with the lumbar counterparts, new designs are being evaluated. DISCUSSION: Although still in the early phases of development, functional disc replacement will become a part of the spine surgeon's armamentarium for the treatment of patients with disc-related pain unresponsive to nonoperative care. The future in this area is exciting and bright with the introduction of new materials and new designs for implants. However, as with any new technology, there must be careful consideration of the safety of the devices, and their effectiveness will only be determined in long-term follow-up studies.

Follow-Up Studies↗

PubMed2003

Lumbar spine arthroplasty: early results using the ProDisc II: a prospective randomized trial of arthroplasty versus fusion.

This study represents the first 39 patients with at least 6-month follow-up enrolled in a prospective randomized Food and Drug Administration study evaluating the safety and efficacy of the ProDisc II versus the control, a 360 degrees lumbar spinal fusion. Data were collected preoperatively and at 6 weeks, 3 months, and 6 months postoperatively. Visual Analog Scale (VAS), Oswestry Low Back Pain Disability Questionnaire (ODQ), and patient satisfaction rates were evaluated at these intervals, as well as range of motion, return to work, and recreational and ambulatory status. There were 28 ProDisc patients and 11 who underwent fusion. Six patients had two-level surgery. Estimated blood loss (ProDisc = 69 mL versus fusion = 175 mL) and operative time (ProDisc = 75 minutes versus fusion = 219 minutes) were significantly different (P < 0.01). Hospital stays were shorter (ProDisc = 2.1 days versus fusion = 3.5 days [P < 0.01]) for ProDisc patients. There was a significantly greater reduction in the ODQ scores at 3 months in the ProDisc group compared with the fusion group (P < 0.05). No difference was noted in VAS. A trend was identified at 6 months in patient satisfaction rates favoring ProDisc versus fusion (P = 0.08), and motion was significantly improved in ProDisc patients compared with the fusion group (P = 0.02). Ambulatory status as well as recreational activity improved faster in the ProDisc group. The data suggest that total disc arthroplasty may be an attractive option as opposed to lumbar fusion for the surgical treatment of disabling mechanical low back pain secondary to lumbar disc disease.

Activities of Daily Living↗

PubMed2003

Prospective study evaluating total disc replacement: preliminary results.

For many years, there has been an interest in disc replacements. There are a few retrospective studies from Europe reporting promising results for these devices. The purpose of this study is to review the preliminary results of the SB Charité disc replacement device in a prospective study. The study group consists of a consecutive series of our first 57 patients who received the Link SB Charité device implanted through a mini-open anterior approach. The primary clinical indications for disc replacement were single-level symptomatic disc disease at L4-L5 or L5-S1 and no significant facet joint changes. The outcome data include the Visual Analog Scale (VAS) assessing pain intensity and the Oswestry Low Back Pain Disability Questionnaire. Data were collected prior to surgery and at 6 weeks, 3 months, 6 months, and 12 months after surgery. Twenty-four-month follow-up data are currently being collected. The mean VAS score improved 50.8% by the 6-week follow-up, and significant improvement was maintained throughout follow-up. The mean Oswestry score improved 38.7% at the 6-week follow-up, and further slight improvement was noted during the later follow-up periods. This study found that significant improvements were achieved by the 6-week postoperative visit in the pain and disability scores following disc replacement surgery. Significant improvement was maintained through the 12-month follow-up visit. Although these preliminary results are encouraging, long-term follow-up and a greater number of patients are needed to further evaluate the outcome of these devices.

Adolescent↗

PubMed2002

Biomechanical evaluation of immediate stability with rectangular versus cylindrical interbody cages in stabilization of the lumbar spine.

BACKGROUND: Recent cadaver studies show stability against axial rotation with a cylindrical cage is marginally superior to a rectangular cage. The purpose of this biomechanical study in cadaver spine was to evaluate the stability of a new rectangular titanium cage design, which has teeth similar to the threads of cylindrical cages to engage the endplates. METHODS: Ten motion segments (five L2-3, five L4-5) were tested. From each cadaver spine, one motion segment was fixed with a pair of cylindrical cages (BAK, Sulzer Medica) and the other with paired rectangular cages (Rotafix, Corin Spinal). Each specimen was tested in an unconstrained state, after cage introduction and after additional posterior translaminar screw fixation. The range of motion (ROM) in flexion-extension, lateral bending, and rotation was tested in a materials testing machine, with +/- 5 Nm cyclical load over 10 sec per cycle; data from the third cycle was captured for analysis. RESULTS: ROM in all directions was significantly reduced (p < 0.05) with both types of cages. There was no significant difference in reduction of ROM in flexion-extension (p = 0.6) and rotation (p = 0.92) between the two cage groups, but stability in lateral bending was marginally superior with the rectangular cages (p = 0.11). Additional posterior fixation further reduced the ROM significantly (p < 0.05) in most directions in both cage groups, but did not show any difference between the cage groups. CONCLUSIONS: There was no significant difference in immediate stability in any direction between the threaded cylindrical cage and the new design of the rectangular cage with endplate teeth.

Journal Article↗

PubMed2002

Artificial disc: preliminary results of a prospective study in the United States.

Artificial discs have been used in Europe for many years with good results. This technology has recently been available in the United States on a limited, investigational basis. The purpose of this study is to review the preliminary results of one center's experience using the SB Charité III disc replacement. The study group consisted of the series of our first consecutive 56 patients who received the Link SB Charité III artificial disc. There were 25 men and 31 women, with a mean age of 39.9 years. All patients had single-level symptomatic disc disruption at L4-5 or L5-S1. The discs were implanted using the same approach as used for mini-open anterior lumbar interbody fusion procedures. The primary data recorded included visual analog scales (VAS) assessing pain and the Oswestry Disability Questionnaire. Data were collected pre-operatively and at 6 weeks, 3 months, 6 months, and 12 months post-operatively. Peri-operative data as well as complications were recorded. At the time of this preliminary study, 22 patients have reached the 12-month post-operative follow-up period. There was a significant improvement in the VAS and Oswestry scores at the 6-week follow-up period. These improvements were maintained throughout the 12-month follow-up period. The preliminary results of this prospective study indicate that the artificial disc yields significant improvement that is maintained during a 12-month follow-up. Data from more patients and with longer follow-up are needed to determine whether these results can be maintained in the long term.

Adolescent↗

PubMedDate not supplied

Prospective randomized study of the Charite artificial disc: data from two investigational centers.

BACKGROUND CONTEXT: For decades there has been a desire to restore motion of a painful degenerated spinal segment. Artificial discs have been used in Europe for almost 20 years. In the few reports available in the literature, the results have been promising. However, there have been no prospective randomized studies comparing artificial discs with spinal fusion. PURPOSE: The purpose of this study was to determine if patients with symptomatic degenerative disc disease treated with Charite artificial disc (DePuy Spine, Raynham, MA) arthroplasty would show significant improvement in functional outcome measures and to compare these results to fusion. STUDY DESIGN/SETTING: This was a prospective randomized clinical trial comparing total disc replacement with anterior lumbar interbody fusion using cages. The data reported were collected from two spine specialty centers participating in a Food and Drug Administration regulated trial. METHODS: A consecutive series of 144 patients were randomized using a 2:1 ratio of Charite versus BAK (Zimmer Spine, Minneapolis, MN). All patients were being treated for single-level discogenic pain confirmed by plain radiography, magnetic resonance imaging and provocative discography. Data were collected at designated follow-up periods for up to 24 months. RESULTS: The mean age was 40.1 years (range, 21 to 56 years). Forty-four cases had BAK anterior interbody fusion, and 100 cases were randomized to Charite disc replacement. The mean operating time was 76.2 minutes (range, 54 to 137 minutes) for the Charite cases. The mean estimated blood loss was 196.2 cc (range, 50 to 1,800 cc). Most patients were discharged in 1 to 2 days with a soft corset and returned to normal activities within 3 weeks if they underwent the disc replacement. The mean Oswestry Disability Index score for the BAK group was 69.6+/-12.8 preoperatively and 27.5+/-26.4 at 24-month follow-up (p<.001) The corresponding mean Oswestry score for the Charite disc patients was 70.9 preoperatively and 30.0 at 24-month follow-up (p<.001). CONCLUSIONS: In this prospective randomized study, both surgical groups improved significantly. Complications of total disc replacement were similar to those encountered with anterior lumbar interbody fusion. Total disc replacement appears to be a viable alternative to fusion for the treatment of single-level symptomatic disc degeneration unresponsive to nonoperative management.

Adult↗

PubMedDate not supplied

Artificial intervertebral discs and beyond: a North American Spine Society Annual Meeting symposium.

BACKGROUND CONTENT: This is a synopsis of a symposium presented to the North American Spine Society Annual Meeting in Seattle, WA, 2001. PURPOSE: To bring to the reader who may not have attended the symposium a distillation of the material presented on this frontier of spinal surgery. METHODS: Panel presentation. RESULTS: The proposed indication for artificial disc replacement is a degenerated but contained disc, painful to the point of major life-style interruption, refractory to at least 1 year of nonoperative treatment, preferably at a single lumbar level and without infection, listhesis or major facet joint disease or spinal stenosis. Total disc replacements have been developed and used mostly in Europe. Disc nucleus replacements have also been developed. No disc replacement has been approved for general use in North America as yet. The US Food and Drug Administration is conducting investigational device exemption studies at this time. CONCLUSIONS: Artificial disc replacement is not a new concept, the first attempts having been done in the early 1950s. During the past 15 years, considerable advance has been made with large numbers of patients, mostly in Europe, having surgery with either total disc prostheses or disc nucleus replacements. Only with truly scientific studies using patient randomization, pre- and postsurgery outcome analyses by unbiased independent observers and statistical analysis by independent experts will the real value of these devices be realized.

Biocompatible Materials↗

PubMedDate not supplied

Lumbar discography.

STUDY DESIGN: A comprehensive review of the literature dealing with lumbar discography was conducted. OBJECTIVE: The purpose of the review is to update the North American Spine Society position statement published in 1994 that addressed criticisms of lumbar discography, to identify indications for SUMMARY OF BACKGROUND DATA: Lumbar discography remains a controversial diagnostic procedure. There are concerns about its safety and clinical value, although many support its use in specific applications. METHODS: Articles dealing with lumbar discography were reviewed and are summarized in this report. RESULTS: Most of the recent literature supports the use of discography in selected patients. Although not to be taken lightly, many of the serious complications and high complication rates reported before 1970 have decreased since then because of improvement in injection technique, imaging and contrast materials. CONCLUSIONS: Most of the current literature supports the use of discography in select situations. Indications for discography include, but are not limited to: (1) Further evaluation of demonstrably abnormal discs to help assess the extent of abnormality or correlation of the abnormality with the clinical symptoms. Such symptoms may include recurrent pain from a previously operated disc and lateral disc herniation. (2) Patients with persistent, severe symptoms in whom other diagnostic tests have failed to reveal clear confirmation of a suspected disc as the source of pain. (3) Assessment of patients who have failed to respond to surgical intervention to determine if there is painful pseudarthrosis or a symptomatic disc in a posteriorly fused segment and to help evaluate possible recurrent disc herniation. (4) Assessment of discs before fusion to determine if the discs within the proposed fusion segment are symptomatic and to determine if discs adjacent to this segment are normal. (5) Assessment of candidates for minimally invasive surgical intervention to confirm a contained disc herniation or to investigate dye distribution pattern before chemonucleolysis or percutaneous procedures. Lumbar discography should be performed by those well experienced with the procedure and in sterile conditions with a double-needle technique and fluoroscopic imaging for proper needle placement. Information assessed and recorded should include the volume of contrast injected, pain response, with particular emphasis on its locations and similarity to clinical symptoms, and the pattern of dye distribution. Frequently, discography is followed by axial computed tomography scanning to obtain more information about the condition of the disc.

Back Pain↗

PubMedDate not supplied

Intervertebral cages for degenerative spinal diseases.

Interbody fusion techniques have been used for many years for the treatment of a variety of lumbar spine diagnoses. Part of the interest in increasing methods of interbody fusion has stemmed from concern that posterior fusion alone may allow micro-motion, which may generate pain in a ruptured or degenerated disc. Stabilization of the anterior segment led to the development of interbody fusion cages. These devices were designed to stabilize the spine while bony ingrowth from the vertebrae to the bone graft occurred. There are a variety of techniques for cage insertion, including open and laparoscopic techniques anteriorly, and open posterior approach. A lateral approach for cage placement has also been reported. The purpose of this paper is to present a review of the literature on lumbar intervertebral fusion performed using interbody cages. The reported results for these procedures vary, but in general the majority of patients have had favorable results. The complications are similar to those encountered with traditional interbody fusion procedures using bone grafts. There is a learning curve associated with the procedures, particularly with the laparoscopic techniques. Appropriate training for the spine surgeon as well as the access surgeon is important. There is a great deal of disparity in reports on using the cages as stand-alone devices as well as on laparoscopic approaches. Overall, the use of interbody cages for fusion appears to be a viable treatment, yielding good results. Fusion cages appear to have a role in spine care; however, as with any procedure, patient selection and proper training of the surgeon are critical.

Humans↗