Biomedical subjects
R A Balderston
Publications and source records attributed to R A Balderston.
Occurrence of infection in anterior cervical fusion for spinal cord injury after tracheostomy.
STUDY DESIGN: This study retrospectively reviewed the outcomes of 11 patients treated for a cervical spine injury with a tracheostomy placed before anterior cervical spine surgery. OBJECTIVES: The primary goal was to show that anterior cervical spine surgery in the setting of spinal cord injury is a viable option in patients with previous tracheostomy. SUMMARY OF BACKGROUND DATA: Respiratory failure after cervical cord injury commonly requires tracheostomy, possibly increasing the risk of soft tissue or bony infection in patients at high risk for morbidity after surgery. Although numerous studies have explored the risk of infection after tracheostomy or anterior cervical spine surgery, no study has been performed to explore the risk of infection in patients with previous tracheostomy at the time of anterior cervical spine surgery. METHODS: A retrospective review of the clinical data of 1800 spinal cord injury patients seen from 1979 to the present at the Regional Spinal Cord Injury Center of the Delaware Valley of Thomas Jefferson University with affiliated institutions of Thomas Jefferson University Hospital and Magee Rehabilitation Hospital was performed. Eleven patients were found who had existing tracheostomy at the time of anterior cervical spine surgery. Clinical follow-up period averaged 28 months with a range of 6-51 months, and radiographic analysis averaged 7 months with a range of 1-51 months. Autogenous iliac crest graft was used in all patients, consisting of an intervertebral graft after a discectomy or a strut graft after a complete corpectomy. Anterior instrumentation was used in more than 50% of the patients. RESULTS: After all patient interviews and review of all radiographs for evidence of infection, no patient was noted to have evidence of a cervical soft tissue or bony infection after surgery. The tracheostomy complications were minor and resolved quickly. CONCLUSIONS: The authors concluded that in patients with cervical cord damage resulting from nonpenetrating trauma, tracheostomy was not found to increase the risk of infection in subsequent anterior cervical surgery. Careful preparation of the skin and placement of the second surgical incision lateral to the tracheostomy site is recommended. Anterior cervical spine surgery remains a viable treatment option in this severely injured patient population.
Health outcome assessment before and after adult deformity surgery. A prospective study.
STUDY DESIGN: Fifty-five patients undergoing surgery for adult spinal deformity assessed their health status using a generic health outcome instrument before surgery and at an average of 2 years after surgery. OBJECTIVE: To assess whether adult spinal deformity surgery is a useful intervention when patients evaluate their own perception of health. The Medical Outcomes Survey Short Form-36, a validated generic health outcome assessment form, was used to measure patient's health status. SUMMARY OF BACKGROUND DATA: Surgery for adult scoliosis is technically demanding. No study that we are aware of uses a generic health outcome instrument in a prospective manner to compare patients' perception of their health after adult scoliosis surgery. The Medical Outcomes Survey Short Form-36 has been validated in multiple studies assessing other medical conditions and was found to be reliable, comprehensive, brief, and generic. METHODS: Sixty-eight adult patients undergoing surgery for adult spinal deformity were prospectively enrolled. Fifty-five patients were available to complete the Medical Outcomes Surgery Short Form-36 after surgery. The scores of the health profile were compared before and after surgery. The results of patients younger than 40 years were compared with those of patients older than 40 years. The results of patients younger than 40 years were compared with those of patients older than 40 years. The results of patients fused to more caudal end vertebral levels ((L4, L5)5) were compared with those who were fused to more cranial end vertebral levels. The results of patients without complications after surgery were compared with those of patients with complications after surgery. RESULTS: Average follow-up period was 22.5 months (minimum 12 months) in 82% of 68 patients. Statistically significant improvements were seen in postoperative scores for physical function, social function, bodily pain, and perceived health change. We found no significant differences in self-reported health function parameters related to age ( > 40 vs. < 40), end vertebral level of fusion, or presence of complications after surgery. CONCLUSIONS: Applying a generic health outcome instrument to adult spinal deformity surgery shows that adult scoliosis surgery significantly improves patient self-reported health assessment and function. Beneficial results do not appear to deteriorate with age or more caudal end vertebral levels of fusion. Future studies combining disease-specific outcomes analysis and generic health surveys to assess end results of adult spinal deformity surgery will be useful.
Postoperative blood salvage in total knee arthroplasty using the Solcotrans autotransfusion system.
One hundred forty-four patients who underwent primary total knee arthroplasty were examined in a prospective controlled study to determine the efficacy and safety of a postoperative wound drainage autotransfusion system (Solcotrans, Smith & Nephew Richards, Memphis, TN). The patients were divided into two groups: control group 1 comprised 88 (61%) patients who either received a Hemovac disposable drainage system (63 patients) or the Solcotrans system and had inadequate drainage for autotransfusion (25 patients). Experimental group 2 comprised 56 (39%) patients who received a Solcotrans drainage system and were autotransfused. The Solcotrans proved itself safe. No sepsis, transfusion reactions, or coagulopathies were associated with autotransfusion, which averaged 524 mL. There were no significant differences between groups 1 and 2 when comparing preoperative and postoperative hemoglobins and hematocrits. The Solcotrans system did not lower homologous blood requirements. Only 1.6% (2 patients) of all patients who autodonated at least 2 units of autologous blood (122 patients) were in need of a homologous blood transfusion in the postoperative period. Thus, although safe, the Solcotrans system was not proven effective in the management of primary total knee arthroplasty patients.
Placement of pedicle screws in the thoracic spine. Part I: Morphometric analysis of the thoracic vertebrae.
We studied the morphology of the thoracic vertebrae in the spines of seventeen human cadavera in order to define parameters that could be used as guidelines for the placement of hooks and screws in the pedicles to obtain internal fixation. We also reviewed computerized tomographic scans of nineteen thoracic spines in living patients who had no evidence of any vertebral deformity. The transverse diameter of the pedicle, which helps to determine the size of the screw, ranged from a mean (and standard deviation) of 4.5 +/- 1.2 millimeters in the fourth thoracic vertebra to a mean of 7.8 +/- 2.0 millimeters in the twelfth thoracic vertebra. The pedicles were inclined anteromedially throughout the thoracic spine, and the angle ranged from 0.3 degree toward the midline in the twelfth thoracic vertebra to 13.9 degrees in the fourth thoracic vertebra. The morphometric data revealed wide variations in the dimensions of the pedicles, demonstrating the importance of accurate preoperative imaging with transaxial computerized tomographic scans to visualize the precise osseous margins and angles of insertion of the thoracic pedicles.
Placement of pedicle screws in the thoracic spine. Part II: An anatomical and radiographic assessment.
We used computerized tomographic scans and subsequent dissections to evaluate the position of ninety pedicle screws that had been inserted bilaterally into the fourth through twelfth thoracic vertebrae of five fresh-frozen cadavera. The screws had been inserted by five experienced spine surgeons without the use of radiographs or imaging studies. Of the ninety screws, thirty-seven were found to have penetrated the cortex of the pedicle. Twenty-one screws had penetrated the medial cortex and entered the spinal canal, and sixteen had penetrated the lateral cortex. The aorta and the esophagus were at greatest risk for injury after advancement of the screws beyond the anterior vertebral cortex. Computerized tomographic scans of the thoracic spine in nineteen living controls who did not have a spinal abnormality confirmed the proximity of the posterior mediastinal structures to the misplaced screws.
Spinal instrumentation.
The past decade has seen a dramatic increase in the availability of spinal instrumentation devices, enabling surgeons to treat a variety of spinal disorders with improved results and lower morbidity. In each anatomic region new fixation systems exist. Improvement in fusion rates with supplemental plate fixation following anterior cervical diskectomies and reconstructions has been demonstrated; these devices can now be applied more safely than ever before. Posterior occipitocervical plating to the C-2 pedicle and C3-6 lateral masses can provide stable fixation despite incompetent posterior arch bony structures. Newer, more rigid anterior thoracolumbar instrumentation allows for correction of thoracolumbar and lumbar scoliosis along fewer levels and with better maintenance of lordosis and is also useful following anterior decompression for tumor and trauma. Segmental hook fixation of the posterior thoracolumbar spine has allowed for improved correction of deformity without increased morbidity or the need for postoperative bracing in many cases. Finally, the use of transpedicular screw fixation of the lumbosacral spine allows for excellent segmental fixation without intact posterior elements, including facet joints, and has significantly improved the fusion rate in lumbosacral fusions.
Comparison of smoking habits between patients with surgically confirmed herniated lumbar and cervical disc disease and controls.
There have been numerous studies that implicate cigarette smoking as a risk factor for the development of back pain or disc disease. The purpose of this article is to review patients who underwent surgery for cervical or lumbar radiculopathy and to investigate the relationship between cigarette smoking and development of surgical disc disease. A cigarette smoking study of 205 surgical patients with lumbar and cervical disc diseases was done, with the surgical patients compared to 205 age-sex-matched inpatient controls during 1987-1988. This study was conducted at the Pennsylvania Hospital in Philadelphia, Pennsylvania. There were 163 patients with lumbar disc disease and 42 patients with cervical disc disease. The ratio of men to women was 1.5:1 for lumbar disc and 2.5:1 for cervical disc disease. Smoking history (current and ex-smokers) was strikingly increased in both prolapsed lumbar intervertebral disc (56% vs. 37% of controls, p = 0.00029) and cervical disc disease (64.3% vs. 37% of controls, p = 0.0025). Calculated relative risks for smokers were 2.2 for lumbar disc and 2.9 for cervical disc diseases. This association between cigarette smoking and disc disease was more significant when comparing between current smokers versus nonsmokers (p = 0.000011 for lumbar disc disease, and p = 0.00064 for cervical disc disease). Relative risks for current smokers were 3.0 for lumbar disc and 3.9 for cervical disc diseases. This correlation was significant for both males (p = 0.000068 for lumbar disc disease, p = 0.043 for cervical disc disease) and females (p = 0.018 for lumbar disc disease, p = 0.006 for cervical disc disease).(ABSTRACT TRUNCATED AT 250 WORDS)
The pullout strength of titanium alloy MRI-compatible and stainless steel MRI-incompatible Gardner-Wells tongs.
The stainless steel Gardner-Wells tongs and pins previously employed to reduce cervical spine fractures are increasingly being replaced by magnetic resonance imaging (MRI)-compatible graphite tongs and titanium pins. Concern regarding the relative pullout strengths of these two systems, however, prompted the performance of a cadaver study in which tongs and pins were placed in 10 cadaver skulls and tested to failure. The MRI-compatible tongs failed due to plastic deformation of the titanium pin tips resulting in tong slippage and loss of fixation, whereas the stainless steel tongs and pins failed when the skull fractured. These results indicated that MRI-compatible systems must be used with extreme caution, particularly when traction exceeds 50 pounds.
Thoracic disc herniation. Re-evaluation of the posterior approach using a modified costotransversectomy.
A consecutive series of 23 thoracic disc herniations in 21 patients treated between 1980 and 1988 were reviewed. All patients were decompressed through a posterolateral approach (costotransversectomy or transpedicular). Pain and weakness were the most common presenting symptoms. Twenty-one thoracic disc herniations in 19 patients were available for long-term follow-up, averaging 58.1 months. Sixteen patients had an excellent or good result. Three patients had a fair result. There were no poor results. All six patients with significant preoperative lower extremity weakness improved. Pain was relieved in 16 patients and reduced in three. There were no significant neurologic complications associated with the procedure. Posterolateral decompression for thoracic disc herniation remains a viable alternative without the inherent risk and morbidity of the transthoracic approach.
Early versus late replacement of autotransfused blood in elective spinal surgery. A prospective randomized study.
The use of autologous blood is a well established and extremely popular technique to decrease the necessity for homologous transfusions and the attendant risks of hepatitis, HIV, and HTLV--I/II infections. The most beneficial timing for autologous reinfusion of predonated blood remains unknown. The present study was undertaken to determine the optimal timing of autologous blood reinfusion in elective spinal surgery. Fifty-seven patients were prospectively individually randomly allocated into early versus delayed reinfusion groups prior to undergoing elective spinal surgery by a single surgeon. Three surgical subgroups were entered into the study: anterior/posterior (A/P) spinal fusion patients, posterior thoracolumbar scoliosis fusion patients (PSF), and degenerative posterior lumbar fusion patients (LF). Randomization was successful in that three was no significant difference in male to female ratio, age, preoperative hemoglobin, or number of units predonated between the early and delayed reinfusion groups. Likewise, there was no significant difference in the details of the operative procedure when compared as a group for the early versus delayed reinfusion groups. A significant increase in the postoperative day #1, 2 and 3 hemoglobin was seen in the early reinfusion group, while there was no significant difference seen in the postoperative day #7 hemoglobin between the early versus delayed reinfusion group. There was no effect of surgical grouping on these significant comparisons. Earlier patient mobilization was also seen in the early reinfusion groups for the A/P and PSF groups. There was no difference in patients' subjective evaluation of satisfaction and discomfort between the early or delayed reinfusion groups as determined by blinded interview on days 1, 3, 5, and 7 postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)
MRI evaluation of fusion mass incorporation after anterior cervical bony fusions: preliminary findings.
While Modic has described certain MRI changes in bone grafts in patients after anterior cervical discectomy and fusion (ACF), no study has evaluated specific MRI signal changes in the fusion mass prospectively and longitudinally. The goal of the present study was to prospectively evaluate MRI changes in ACF grafts in a longitudinal fashion. Twenty-seven MRIs were included in the evaluation of seven postoperative patients. MRIs were obtained in a 1.5 tesla GE imager immediately postoperatively, and at 1, 3, and 6 months in most patients. All patients received at least three sequential MRIs. Two patients had greater than one level fused. T1 and T2 images were evaluated in all patients at each available interval. GRASS images were not found to be helpful secondary to a prohibitive amount of noise. For single level fusion masses, T1 images showed a very intense homogeneous graft signal in the immediate postoperative period which decreased slightly at 1 month. At 3 months the signal intensity of the graft was similar to the 1 month image, but was slightly less homogeneous. At 6 months, the T1 signal had greatly decreased in much of the graft. Immediate postoperative specimens showed heterogeneously high signal on T2 images which increased at 1 month in the whole graft, and then seemed to increase at the endplates while decreasing in the graft at 3 months. At 6 months the graft was becoming difficult to delineate on T2 images in many specimens. The two and three level fusions had a more heterogeneous image progression without clear evidence of solid fusion at 6 months.(ABSTRACT TRUNCATED AT 250 WORDS)
Upper lumbar disc herniations.
This study reviews the presentation, diagnosis, and outcomes of upper lumbar disc herniations (L1-2, L2-3, L3-4). One hundred forty-one patients operated upon at three centers between 1980 and 1990 were analyzed (102 men, 39 women; 3 L1-2, 21 L2-3, 117 L3-4; average age 51.6 years; 10.4% of all lumbar discectomies performed). Preoperative signs and symptoms were highly variable. Sensory, motor, and reflex testing was variable and potentially misleading in suggesting a level of herniation. In analyzing radiographic studies (noncontrast CT, myelography, MRI) individually and using other radiographic studies and operative findings as a standard for comparison, a high false-negative rate was found for all studies when considered individually, especially at the higher L2-3 level. Intraoperative radiographs were employed with increasing frequency as the level of herniation ascended. Six operative complications (4.3%) were identified, all of which were treated and were resolving at the time of discharge. Follow-up obtained at an average of 2.2 years in 87% of patients by chart review showed no reoperations or late complications. Noncompensation patients had a significantly higher percentage of good/excellent results (86%) than those with compensation or legal claims pending (45% good/excellent results). Based upon these data, we recommend myelogram with postmyelogram CT and/or MRI in the workup of these patients and intraoperative radiographs in all cases when decompressing an upper lumbar disc herniation. Patients with compensation/legal claims should be approached cautiously, because their subjective results are significantly worse than those of noncompensation patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Concomitant noncontiguous thoracolumbar and sacral fractures.
Seventeen patients were identified with concomitant thoracolumbar and sacral fractures representing 26% of sacral fractures and 7.7% of pelvic fractures. The thirteen men and four women exhibited a bimodal age distribution. There were thirteen vertical compression thoracolumbar fractures, three transverse process fractures, and one traumatic herniated nucleus pulposus. There were seven Zone I, seven Zone II, and three Zone III sacral fractures using the Denis classification. Five of the sacral fractures were missed on initial presentation. Four of the patients had neurogenic bowel or bladder symptoms. Seven of the thoracolumbar fractures and three of the sacral fractures were treated operatively. Results were generally good or excellent unless significant neurologic injury was present at initial presentation. The authors recommend aggressive computed tomographic evaluation of the sacrum in any suspicious pelvic trauma or when the neurologic lesion does not match the more proximal bony lesion. They hypothesize that decompression of both sacral and thoracolumbar lesions may be necessary if either lesion could be responsible for neurogenic bowel or bladder symptoms.
The results of operations on the lumbar spine in patients who have diabetes mellitus.
The results for sixty-two patients who had had a diagnosis of diabetes mellitus and lumbar disc disease or spinal stenosis and had been managed with a posterior decompressive procedure were compared, in a retrospective study, with those for sixty-two age and sex-matched non-diabetic (control) patients who had had similar operative procedures. Forty-four of the sixty-two diabetic patients and fifty-five of the non-diabetic patients were available for long-term follow-up (mean, five and seven years, respectively). Among the diabetic patients, there were high rates of postoperative infection and prolonged hospitalization compared with the rates for the control group. The long-term result was excellent or good for seventeen (39 per cent) of the forty-four patients who had diabetes mellitus and for fifty-two (95 per cent) of the fifty-five non-diabetic patients. The poor results in the diabetic patients may have been related to coexisting diabetic neuropathy, to the associated microvascular disease that affects the spinal nerve roots in diabetic patients, or to the failure of the nerve roots of these patients to recover after decompressive procedures.
Complications of trochanteric osteotomy. Long-term implications.
Cemented total hip arthroplasties (THAs) were performed through a Charnley transtrochanteric approach in 1162 patients from 1970 through 1986. Trochanteric separations numbered 58 (5%). Rate of nonunion was related to gender, preoperative diagnosis, and prior THA or endoprosthesis. Nonunion patients had lower mean Charnley pain and function mean scores than union patients at the 45- and 49-month examinations, respectively. A Trendelenberg gait was noted in 17% of nonunions compared with 6% of united patients. Revision rates were nearly three times higher in nonunion patients. These results indicate there is a quantifiable risk for a surgeon who chooses to use a trochanteric osteotomy.
Cemented versus cementless total hip arthroplasty. A comparative study of equivalent patient populations.
Seventy-one cemented total hip arthroplasties (THAs) in 66 patients were compared with 70 cementless THAs in 61 patients. The cemented and cementless components were identical except for the presence of a porous proximal surface on the cementless component. The mean follow-up time was 4.3 years in the cemented group and 4.1 years in the cementless group, with a minimum follow-up of two years. Postoperative Charnley pain scores were identical for both groups, as was the incidence of limp. The final Charnley function score, however was significantly higher in the cementless group (5.6) than in the cemented group (5.1). One revision was performed in the cemented group, none in the cementless group. Complete demarcation of the bone-cement interface was presented in two cemented components and was associated with subsidence. Three cementless components had early subsidence, and two of these had complete radiopaque lines around the porous surface. None of these three patients, however, had unsatisfactory pain or function scores. The most important finding of this study is the equivalence of clinical results noted in both cemented and cementless THA as late as six years after operation.
A prospective randomized comparison of two surgical approaches to total hip arthroplasty.
One hundred patients had total hip arthroplasty (THA) with either a modified Hardinge approach or transtrochanteric lateral approach. Perioperative data showed that osteotomies resulted in significantly more blood loss but required shorter operative time. Postoperative pain, using a visual analog scale, showed no statistical difference between the two groups. Postoperative hip scores for pain, function, and range of motion (ROM), presence of limp, and abductor muscle strength scores showed no significant difference between groups at six months and one year. Roentgenographic follow-up evaluation showed a mean acetabular cup angle of 40 degrees and a neutral-to-valgus femoral stem position in all patients. Trochanteric union was present in 92%. Heterotopic ossification occurred predominantly in the Hardinge patients but was not functionally significant. Therefore, the ability to achieve adequate pain relief and function with THA is not affected by the type of approach.