Improved response of osteoprogenitor cells to titanium plasma-sprayed PEEK surfaces.

Orthopedic implants benefit from a surface that encourages direct bony ongrowth (contact osteogenesis). This process is initiated as osteoprogenitor cells attach to the implant surface and deposit a calcium-enriched, collagen-deficient interfacial layer known as the cement line, which provides an anchoring foundation for the subsequent production of collagenous bone matrix from differentiated osteoblasts. Despite the importance of the cement line, the conditions affecting its deposition are incompletely understood.

100 consecutive cases of degenerative lumbar conditions using a non-threaded locking screw system with a 90-degree locking cap.

Background: This prospective study analyzes the perioperative outcomes and long-term fusion success of 100 consecutive lumbar degenerative cases. The cases were managed using a non-threaded locking screw system, in conjunction with polyetheretherketone (PEEK) cages, for posterior lumbar interbody fusion (PLIF) procedures. These 100 cases were compared to another prospective study treating patients with the same inclusion and exclusion criteria using conventional plate-based pedicle screw spinal instrumentation augmented with carbon fiber interbody cages.

Distribution of in vivo and in vitro range of motion following 1-level arthroplasty with the CHARITE artificial disc compared with fusion.

Object: One of the goals of lumbar arthroplasty is to restore and maintain range of motion (ROM) and to protect adjacent levels from abnormal motion, which may be a factor in transition syndrome following arthrodesis. In this study, in vitro ROM results were compared with in vivo, 2-year postoperative radiographic ROM evaluations.

Methods: Radiographs of patients enrolled in the CHARITE investigational device exemption study were analyzed at baseline and at 2 years postoperatively.

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.

The indications for interbody fusion cages in the treatment of spondylolisthesis: analysis of 120 cases.

Study Design: This study retrospectively examines outcomes of unilateral transforaminal lumbar interbody fusion (TLIF) with posterior fixation using anterior carbon fiber cages and 360 degrees fusion in spondylolisthesis.

Objectives: The goals were to examine the outcomes and perioperative complications of using anterior column support in the treatment of various types of spondylolisthesis.

Summary Of Background Data: In 2000, Brantigan et al reported the Brantigan interbody fusion cage used as a posterior lumbar interbody fusion in the US IDE clinical trial.

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.

Osseointegration of autograft versus osteogenic protein-1 in posterolateral spinal arthrodesis: emphasis on the comparative mechanisms of bone induction.

Background Context: Recent studies have documented increased fusion success afforded by bone morphogenetic proteins versus autogenous graft for posterolateral spinal arthrodesis.

Purpose: The current study was designed to investigate the time-course maturation processes of lumbar posterolateral arthrodeses performed with Osteogenic Protein-1 (Stryker Biotech, Inc., Hopkinton, MA, USA) (rhOP-1) versus "gold standard" autograft.

Experimental design of total disk replacement-experience with a prospective randomized study of the SB Charitè.

Study Design: Prospective randomized clinical trial.

Objectives: To determine if a prospective randomized study of patients with symptomatic degenerative disc disease treated with disc arthroplasty could be safely completed.

Methods: Sixty patients with one-level discogenic pain confirmed by plain radiography, magnetic resonance imaging, and provocative discography for degenerative disc disease were randomized comparing 1/3 BAK anterior interbody fusion and 2/3 anterior SB Charitè artificial disc replacement.

SB Charité disc replacement: report of 60 prospective randomized cases in a US center.

Sixty patients with one-level discogenic pain confirmed by plain radiography, magnetic resonance imaging, and provocative discography for degenerative disc disease were randomized: one-third BAK anterior interbody fusion and two-thirds anterior SB Charité artificial disc replacement. The mean age was 40.3 years (range 21-56 years).

Analysis of porous ingrowth in intervertebral disc prostheses: a nonhuman primate model.

Study Design: A study was conducted to investigate the biomechanical, histochemical, and biologic ingrowth characteristics of the most widely used total disc prosthesis, the hydroxyapatite-coated SB Charité prosthesis.

Objective: To compare the porous ingrowth, linear apposition, or bony ingrowth in total disc replacement with published reports of porous ingrowth prostheses in the appendicular skeleton.

Methods: Seven mature baboons (Papio cynocephalus) underwent L5-L6 total disc replacement through an anterior transperitoneal approach.

Anterior BAK instrumentation and fusion: complete versus partial discectomy.

Beginning in January 1994, a prospective, clinical study was done comparing the effectiveness of complete anterior (Group 1) versus partial reamed channel discectomies (Group 2) in 100 consecutive patients who had anterior BAK instrumentation and fusion using autogenous iliac crest bone graft. At 2 or more years of followup, all patients in Group 1 who had complete operative disc removal achieved solid arthrodesis. There were no revision surgeries.

Revision strategies for salvaging or improving failed cylindrical cages.

Study Design: This is a review of 20 patients who experienced failure of threaded interbody fusion cages and underwent surgical correction.

Objective: To review the causes and possible treatment strategies for failed cylindrical cages.

Summary Of Background Data: Intraoperative complications have been described in the past; however, management of the postoperative patient with failure of interbody fusion devices has not been described.

Osteogenic protein versus autologous interbody arthrodesis in the sheep thoracic spine. A comparative endoscopic study using the Bagby and Kuslich interbody fusion device.

Study Design: Using an in vivo interbody arthrodesis model, the efficacy of the Bagby and Kuslich (BAK) device packed with recombinant human osteogenic protein-1 (rhOP-1) was evaluated.

Objectives: To compare the efficacy of osteogenic protein with that of autograft for interbody arthrodesis, with fusion success based on biomechanical, histologic, and radiographic analyses.

Summary Of Background Data: The use of recombinant human bone morphogenetic proteins (rhBMPs) as osteoinductive bone graft substitutes or expanders has recently gained considerable research interest, particularly when applied in posterolateral arthrodesis.

Minimally invasive anterior retroperitoneal approach to the lumbar spine. Emphasis on the lateral BAK.

Study Design: Eighteen patients with lumbar instability from fractures, postlaminectomy syndrome, or infection were treated prospectively with minimally invasive retroperitoneal lumbar fusions.

Objectives: To determine if interbody Bagby and Kuslich fusion cages and femoral allograft bone dowels can be inserted in a transverse direction via a lateral endoscopic retroperitoneal approach to achieve spinal stability.

Summary Of Background Data: Endoscopic spinal approaches have been used to achieve lower lumbar fusion when instrumentation is placed through a laparoscopic, transperitoneal route.

Video-assisted thoracoscopic surgery versus open thoracotomy for anterior thoracic spinal fusion. A comparative radiographic, biomechanical, and histologic analysis in a sheep model.

Study Design: In this in vivo investigation, a sheep model was used to compare the efficacy of a video-assisted thoracoscopic approach and a traditional thoracotomy in promoting a successful interbody spinal arthrodesis.

Objectives: To compare the incidence of successful anterior spinal arthrodesis among three stabilization techniques-iliac crest, Bagby and Kuslich device, and Z-plate--performed using a video-assisted thoracoscopic approach and conventional open thoracotomy approaches.

Summary Of Background Data: A clinical outcome study on open versus endoscopic spinal fusion is not yet available.

Minimally invasive surgical techniques to treat spine infections.

Minimally invasive techniques including closed laparoscopy and thoracoscopy as well as video-assisted procedures using limited open incisions provide an excellent alternative for treating vertebral osteomyelitis and tuberculous infections in the thoracic and lumbar spine. The traditional principles of surgical debridement and a stable interbody fusion are unchanged when applying endoscopic techniques. In the future, the spinal endoscopist will have available a larger selection of endoscopic instruments, more sophisticated video technology, and the development of anterior instrumentation systems to allow for rigid internal fixation.

Anterior thoracic corpectomy for spinal cord decompression performed endoscopically.

A prospective study was undertaken during the past 3 years to investigate the effectiveness of thoracoscopic corpectomy--endoscopic removal of the vertebral body in 15 cases (8 for pathologic fractures for tumors, 5 for traumatic fractures and 2 for infections). The average age of the patients was 53.2 years (range 28-85 years).

The incidence of complications in endoscopic anterior thoracolumbar spinal reconstructive surgery. A prospective multicenter study comprising the first 100 consecutive cases.

Study Design: A prospective multicenter study on 100 consecutive surgical procedures.

Objectives: A prospective multicenter study was performed to evaluate the early perioperative complications in 100 endoscopic spinal procedures--78 video-assisted thoracic surgical procedures and 22 laparoscopic lumbar instrumentation and fusion procedures.

Summary Of Background Data: Endoscopic procedures have been widely applied in general surgery for appendectomy, cholecystectomy, liver resection, Nissen fundoplication, colon resection, and hernia repairs.

Relationship of morphine-induced miosis to plasma concentration in normal subjects.

The relationship between morphine plasma concentration and pupil diameter was evaluated 2-10 h following intravenous administration of morphine sulfate (10 mg). Seven healthy male volunteers received 10 mg of morphine intravenously following pretreatment for 4 d with either cimetidine (300 mg po four times a day) or placebo in a single blind, balanced crossover study. Pupil diameters were measured directly from contact prints using calipers and a photographed millimeter scale.

Bucindolol, a beta-adrenoceptor blocker with vasodilatory action: its effect in systemic hypertension.

Bucindolol is a newly developed, nonselective beta-adrenergic blocking agent with intrinsic sympathomimetic activity and direct vasodilator properties. In 14 patients with mild to moderate essential hypertension, the effects of bucindolol, hydrochlorothiazide and their combination on blood pressure (BP), heart rate (HR) and parameters of the renin-aldosterone system were compared with those after placebo. Bucindolol's antihypertensive effect was evident within the first hour after drug administration, maximal at 2 to 3 hours, and lasted for as long as 12 hours.

Effect of intravenous carbenicillin, cefoxitin and cefamandole on ADP-induced platelet aggregation and shape change.

The effect of a large daily dose of i.v. carbenicillin, cefoxitin and cefamandole on platelet aggregation with adenosine diphosphate (ADP) and the effect of carbenicillin on ADP induced shape change were evaluated.

Cimetidine does not alter morphine disposition in man.

1 The pharmacokinetic parameters of morphine were determined in a crossover fashion following 4 days pretreatment with cimetidine, 300 mg every 6 h, or placebo. 2 Cimetidine had no apparent effect on the mean morphine plasma clearance, volume of distribution, AUC or half-life (P greater than 0.05; power greater than 0.