PubMed Health⌕ Search

Biomedical subjects

John A McCulloch

Publications and source records attributed to John A McCulloch.

6 recordsLinked to original sources
PubMed2005

Comparison of OP-1 Putty (rhBMP-7) to iliac crest autograft for posterolateral lumbar arthrodesis: a minimum 2-year follow-up pilot study.

STUDY DESIGN: A prospective, randomized, controlled, multicenter clinical study. OBJECTIVE: To compare the safety and clinical and radiographic outcomes of OP-1 (BMP-7) Putty to autogenous iliac crest bone graft in a population of patients undergoing laminectomy and posterolateral fusion for symptomatic lumbar stenosis associated with degenerative spondylolisthesis. SUMMARY OF BACKGROUND DATA: Although the existing preclinical and clinical data suggest that OP-1 is able to achieve osteoinduction and clinical fusion in a variety of situations, the efficacy of this recombinant protein in a clinical spine fusion population has not been fully elucidated. This study directly compares the efficacy and safety of OP-1 putty to autograft bone for arthrodesis in patients with symptomatic stenosis in association with degenerative spondylolisthesis. METHODS: Thirty-six patients with degenerative lumbar spondylolisthesis and symptoms of neurogenic claudication underwent laminectomy, bilateral medial facetectomy, and posterolateral fusion using either iliac crest autograft or OP-1 Putty. Oswestry scores and SF-36 questionnaires were used to determine the clinical response to treatment. Independent, blinded neuroradiologists reviewed both static and dynamic radiographs to determine the fusion status. Successful fusion was declared whenthe presence of continuous bridging bone between the transverse processes was observed and less than 5 degrees of angular motion and 2 mm of translational movement was measured using digital calipers. RESULTS: Efficacy data were tabulated for 27 patients at the 24-month time point and an additional 4 patients (without evaluable 24-month results) at the 36-month time point. One patient was not evaluable for radiology, so the data reflect clinical information for 31 patients and radiology for 30 patients. Clinical success, defined as a 20% improvement in the preoperative Oswestry score, was achieved by 17 of 20 (85%) OP-1 Putty patients and 7 of 11 (64%) autograft patients. A successful posterolateral fusion was achieved in 11 of 20 (55%) OP-1 Putty patients and 4 of 10 (40%) autograft patients. SF-36 scores showed similar clinical improvement in both groups. No systemic toxicity, ectopic bone formation, recurrent stenosis, or other adverse events specifically related to the use of the OP-1 Putty implant were observed. CONCLUSION: This study represents the first clinical trial to demonstrate the safety and similarity of OP-1 Putty as a replacement for autogenous bone graft in the posterolateral fusion environment with a minimum of 2-year follow-up. OP-1 Putty was able to achieve osteoinduction leading to a radiographically solid fusion in the absence of autogenous iliac crest bone graft in 55% of the patients at 24 and 36 months. These results compare favorably to the historical fusion rates reported for uninstrumented arthrodesis in this challenging clinical scenario.

Adult↗
PubMed2004

A pilot study evaluating the safety and efficacy of OP-1 Putty (rhBMP-7) as a replacement for iliac crest autograft in posterolateral lumbar arthrodesis for degenerative spondylolisthesis.

STUDY DESIGN: A prospective, randomized, controlled, multicenter clinical study was conducted. OBJECTIVE: To compare the clinical and radiographic outcomes of patients treated with OP-1 (BMP-7) Putty to autogenous iliac crest bone graft for one-level uninstrumented posterolateral fusion of the lumbar spine following decompressive laminectomy for the treatment of symptomatic degenerative spondylolisthesis with spinal stenosis. BACKGROUND: Preclinical studies have demonstrated that osteoinductive recombinant human osteogenic protein 1 in the form of OP-1 Putty is successful at achieving a posterolateral fusion in rabbits and dogs without any significant safety concerns. METHODS: Thirty-six patients with degenerative lumbar spondylolisthesis and symptoms of neurogenic claudication were randomized (2:1) to either OP-1 Putty (3.5 mg of OP-1 per side) or autogenous iliac crest bone graft for one-level uninstrumented posterolateral fusion following a decompressive laminectomy. Enrollment in the study was complete when 24 OP-1 Putty patients and 12 autograft patients had been randomized and treated. A patient administered Oswestry scale and SF-36 scale were used to determine clinical outcomes. Independent, blinded neuroradiologists reviewed both static and dynamic radiographs to determine fusion status. RESULTS: At the 1-year follow-up, 32 patients were available for clinical analysis and 29 patients were available for radiographic review. Clinical success as measured on the Oswestry scale was achieved by 18 of 21 (86%) OP-1 Putty patients and 8 of 11 (73%) autograft patients. SF-36 pain index scores showed similar results. Fourteen of 19 (74%) OP-1 Putty patients and 6 of 10 (60%) autograft patients achieved a successful posterolateral fusion fulfilling all fusion criteria. Of the 29 evaluable patients, 15 were both clinical and radiographic successes, 5 were radiographic successes but were clinical failures, 1 patient was both a radiographic and clinical failure, and 8 patients were radiographic failures but were clinical successes. No systemic toxicity, ectopic bone formation, recurrent stenosis, or other adverse events related to the OP-1 Putty implant were observed. CONCLUSION: Although the posterolateral spine is a challenging fusion environment in patients with degenerative spondylolisthesis, successful radiographic fusion was obtained using OP-1 Putty at a rate that was similar to autograft given the number of patients in this study. Importantly, there were no apparent adverse consequences related to the use of the OP-1 Putty implant in this patient population.

Adult↗
PubMed2003

Microsurgery for degenerative conditions of the cervical spine.

Although the operating microscope has been used for spine surgery for more than 20 years, its use is still not widely accepted by orthopaedic spine surgeons. Nevertheless, surgeons who have used the operating microscope are well aware of its many advantages in performing spine surgery. Most notably, the superior visualization it provides allows for faster, safer, and more extensive decompressions. The reluctance of many surgeons to use the operating microscope often has to do with trepidation regarding new technology. The use of the operating microscope when performing anterior and posterior cervical spine surgery makes these procedures easier to carry out and decreases the risk of complications during decompression of the spinal cord.

Cervical Vertebrae↗
PubMed2002

The lateral buttress: an anatomic feature of the lumbar pars interarticularis.

STUDY DESIGN: A morphometric study of the lateral buttress region of the lumbar pars interarticularis from L1-L5 on 10 dried lumbar spines was performed. OBJECTIVE: To qualitatively describe and quantitatively evaluate this portion of the pars and to discuss its clinical and surgical relevance. BACKGROUND: The "lateral buttress" is a bony bridge connecting the superolateral edge of the inferior facet to the pedicle/transverse process junction, offering structural support to the pars interarticularis at upper lumbar levels. To date, no anatomic study has evaluated this structure. METHODS: Direct measurements using vernier calipers were taken at each level, L1-L5, from 10 dried lumbar spines. Surface area of the buttress was calculated and compared statistically for differences between each level, as well as normalized relative to L3. RESULTS: The surface areas of the buttresses at L1-L3 were similar, measuring near 80 +/- 10 mm2. At L4, it measured 50 +/- 10 mm2. And at L5, it measured 15 +/- 5 mm2. These differences were statistically significant. Normalized data showed the buttress at L4 to be 40% smaller and at L5 to be 80% smaller than at upper levels. CONCLUSIONS: This study provides descriptive and anatomic data regarding the lateral buttress portion of lumbar pars interarticularis. The broad buttress of the upper lumbar levels offers support to the pars but can confuse anatomic guidelines for pedicle screw placement and paraspinal approaches. The narrow buttress of lower lumbar levels makes pedicle screw placement and the paraspinal approach easier, but it lessens support to the pars, making spondylolysis and iatrogenic instability more likely.

Humans↗
PubMed2002

Microsurgery in the lumbar intertransverse interval.

The intertransverse interval has long been known as a place to lay bone graft in hope of achieving a solid arthrodesis. Opening it to use the interval to gain access into the foraminal and extraforaminal regions of the spinal canal has only recently been done. The anatomy is simple and embodies a common lumbar spine principle, which is to find a pedicle, because medial to it will be a nerve root. In the intertransverse interval, the lateral border of the pars interarticularis is on the same sagittal plane as the medial border of the pedicle (except for L5). Once through the interlaminar window, the anatomy is very simple--there is only one nerve root to find. The limited ability to manipulate instruments and the increased depth of the exposure make the use of the operating microscope very important. More so than axial MRI cuts and far more so than axial CT cuts, parasagittal MRI cuts reveal a true picture of the openness of the foramen. The type of pathology, whether E/FLDH or foraminal stenosis, can be clearly delineated on parasagittal MRI. It is important, however, that radiologists not overcall foraminal stenosis on axial cuts, either CT or MRI. Foraminal stenosis is easily decompressed by a lateral approach and is very difficult to completely decompress from within the spinal canal. If foraminal stenosis has been left behind from a previous midline SCS decompression, and if the patient has continuing leg pain, then it is easy to avoid the previous midline surgical route and take a paraspinal muscle-splitting approach to complete the foraminal decompression. Other, as yet undiscovered uses for the intertransverse window approach likely exist. The senior author has used this approach to remove a third- or fourth-time recurrent canalicular disk herniation where the fragment is opposite the disk space (the usual situation). By avoiding the previous scarred-in canal and nerve root, it has been possible to remove the ruptured disk. Visualization, however, is not good with this approach.

Decompression, Surgical↗