Intraosseous basivertebral nerve ablation for the treatment of chronic low back pain: a prospective randomized double-blind sham-controlled multi-center study.

PURPOSE: To evaluate the safety and efficacy of radiofrequency (RF) ablation of the basivertebral nerve (BVN) for the treatment of chronic low back pain (CLBP) in a Food and Drug Administration approved Investigational Device Exemption trial. The BVN has been shown to innervate endplate nociceptors which are thought to be a source of CLBP. METHODS: A total of 225 patients diagnosed with CLBP were randomized to either a sham (78 patients) or treatment (147 patients) intervention. The mean age within the study was 47 years (range 25-69) and the mean baseline ODI was 42. All patients had Type I or Type II Modic changes of the treated vertebral bodies. Patients were evaluated preoperatively, and at 2 weeks, 6 weeks and 3, 6 and 12 months postoperatively. The primary endpoint was the comparative change in ODI from baseline to 3 months. RESULTS: At 3 months, the average ODI in the treatment arm decreased 20.5 points, as compared to a 15.2 point decrease in the sham arm (p = 0.019, per-protocol population). A responder analysis based on ODI decrease ≥ 10 points showed that 75.6% of patients in the treatment arm as compared to 55.3% in the sham control arm exhibited a clinically meaningful improvement at 3 months. CONCLUSION: Patients treated with RF ablation of the BVN for CLBP exhibited significantly greater improvement in ODI at 3 months and a higher responder rate than sham treated controls. BVN ablation represents a potential minimally invasive treatment for the relief of chronic low back pain. These slides can be retrieved under Electronic Supplementary Material.

Outcome of unoperated discogram-positive low back pain.

STUDY DESIGN: No previous discography study has addressed the nonoperative outcome of low back pain. OBJECTIVES: This study was undertaken to retrospectively analyze the outcome of patients with documented single-level discogenic pain who were considered candidates for surgery but did not receive it. SUMMARY OF BACKGROUND DATA: The natural history of "discogenic" low back pain is unknown, and its treatment is controversial. Although positive discography is viewed as a valid diagnostic technique, the results of fusion surgery are often disappointing. METHOD: Twenty-five individuals (16 women, 9 men) underwent comprehensive evaluation (examination, radiography, objective disability determination). Study criteria included incapacitating low back pain, single-level + morphologic + provocative discogram, no surgery, and a minimum follow-up period of 3 years. RESULTS: Average age of patients at discography was 43 years and at study was 48 years; level of involvement in 10 patients was L4-L5 and in 15 patients were L5-S1. The mean follow-up period was 4.9 years (range, 3.3-7.0 years). The condition of 17 (68%) patients improved, two (8%) stayed the same, and six (24%) worsened. Improved patients had a shorter history of low back pain (3.5 yr vs. 11.0 yr) and older age at onset (45 versus 33 yrs.) Psychiatric disease was present in 66.7% (4 of 6) patients whose conditions worsened. Eighty percent (12 of 15) of patients receiving workers' compensation improved. There was no correlation between disc level, gender, smoking, and outcome. CONCLUSIONS: Discogenic low back pain improved in patients without psychiatric disease. Older age at onset and shorter duration of low back pain were favorable indicators. These results are comparable with or better than those reported for surgical treatment of this condition.

Far lateral disc herniations treated by microscopic fragment excision. Techniques and results.

STUDY DESIGN: This was a retrospective review of a consecutive series of patients who underwent excision of far lateral disc herniations by a paraspinal, muscle-splitting incision that spares the facet. OBJECTIVE: The authors describe the surgical technique in detail and review the results of surgical treatment. SUMMARY OF BACKGROUND DATA: As the lumbar nerve roots exit the intervertebral foramen, they once again lie in juxtaposition to an intervertebral disc and are susceptible to compression with subsequent radiculopathy. Radiculopathy caused by disc herniations in this area is less common, and the anatomy is less familiar to spinal surgeons than that of paramedian disc herniations. The involved root can be approached by a transfacetal approach or by a muscle-splitting approach that spares the facet. METHODS: Thirty-one consecutive patients had undergone the muscle-splitting approach to far-lateral disc herniations. Twenty-five (80.6%) of these patients were available for evaluation at a minimum of 2 years after surgery. Evaluation consisted of history, pain questionnaires, visual analogue scales, physical examination, and plain radiographs. RESULTS: Twelve patients (48%) had excellent results, eight (32%) had good, and five (20%) had either fair or poor results. Low back pain and dysesthesias were causes of unsatisfactory results. No radiographic sign of instability developed postoperatively. CONCLUSION: The anatomy of the nerve root lateral to the pedicle and our technique for microscopic excision of herniated disc fragments lateral to the facet are described. Our overall results were encouraging. The described microscopic technique will hopefully minimize dysesthetic pain that appears to be the result of the manipulation of the dorsal root ganglion.

A paradigm for human body finite element model integration from a set of regional models.

Computational modeling offers versatility, scalability, and cost advantages to researchers in the trauma and injury biomechanics communities. The Global Human Body Models Consortium (GHBMC) is a group of government, industry, and academic researchers developing human body models (HBMs) that aim to become the standard tool to meet this growing research need. The objective of this study is to present the methods used to develop the average seated male occupant model (M50, weight = 78 kg, height = 175 cm) from five separately validated body region models (BRMs). BRMs include the head, neck, thorax, abdomen, and a combined pelvis and lower extremity model. Modeling domains were split at the atlanto-occipital joint, C7-T1 boundary, diaphragm, abdominal cavity (peritoneum/retroperitoneum), and the acetabulum respectively. BRM meshes are based on a custom CAD model of the seated male built from a multi-modality imaging protocol of a volunteer subject found in literature.[1] Various meshing techniques were used to integrate the full body model (FBM) including 1-D beam and discrete element connections (e.g. ligamentous structures), 2D shell nodal connections (e.g. inferior vena cava to right atrium), 3D hexahedral nodal connections (e.g. soft tissue envelope connections between regions), and contact definitions varying from tied (muscle insertions) to sliding (liver and diaphragm contact). The model was developed in a general-purpose finite element code, LS-Dyna (LTSC, Livermore, CA) R4.2.1., and consists of 1.95 million elements and 1.3 million nodes. The element breakdown by type is 41% hexahedral, 33.7% tetrahedral, 19.5% quad shells and 5% tria shell. The integration methodology presented highlights the viability of using a collaborative development paradigm for the construction of HBMs, and will be used as template for expanding the suite of GHBMC models.

Reassessment of the surgical scrub.

This study was designed to reassess the efficacy and necessity of the preoperative ten minute, two brush scrub method currently required for all personnel at this hospital. Three scrub methods-the tem minute, two brush technique with an iodophor, Betadine surgical scrub; a five minute, no brush iodophor scrub with a new iodophor iodine scrub, and a three minute, no brush scrub with plain soap and Septisol Foam-were compared. Fingertip culture results obtained prescrub, immediately postscrub and one hour after wearing gloves revealed no significant differences in the three methods. The findings suggest that, one hour after scrubbing, a shorter, no brush scrub procedure with any of the antiseptics used in this study is as effective in reducing bacterial growth of the hands as the standard longer two brush method. By deletion of the use of scrub brushes and the improved efficiency from the reduced scrub time alone with the additional less likelihood of skin trauma and dermatitis, substantial financial savings may be realized.

Responses of the gravid uterine vasculature to arterial levels of local anesthetic agents.

Responses of the uterine vasculature and myometrium to uterine arterial infusions of local anesthetic agents were evaluated in chronically prepared conscious ewes between 86 and 141 days of gestation. Decreases in uterine blood flow (UBF) with increasing levels of anesthetic drugs were similar to those previously observed in nonpregnant ewes. A 25% decrease in UBF occurred at 7 micrograms of bupivacaine, 11.5 micrograms of 2-chloroprocaine, and 19.5 micrograms of lidocaine per milliliter of control UBF. Myometrial tonus did not change significantly except with bupivacaine where an increase occurred (P less than 0.001). These data indicate that local anesthetic agents may lower gravid UBF by a direct vascular effect and by stimulation of myometrial contractility. The possible clinical implications of these observations are discussed.

Two-hole plate fixation for traumatic symphysis pubis diastasis.

Techniques for managing traumatic diastasis of the pubic symphysis include bed rest, hip spica casting, pelvic slings, external fixation, and internal fixation. We report herein our experience with 14 consecutively managed patients in whom we successfully stabilized traumatic pubic diastasis with a single two-hole plate fixation. The average age of the 13 men and one woman was 30 years; followup averaged 17 months. Most of the patients had associated injuries (Injury Severity Score average, 19). Nine patients had concomitant disruption of the sacroiliac joint requiring either delayed open reduction and internal fixation or prolonged skeletal traction; among the five remaining patients, time to mobilization (bed to chair) averaged 1 day. There were no complications attributable to the procedure; i.e., no infections, and no failures of fixation. In this small series of patients early two-hole plate fixation of the traumatic diastasis of the pubis satisfactorily restored the disrupted anterior pelvic ring, contributed to early mobilization of the patients, and made reduction of a concomitantly disrupted sacroiliac joint easier, whether accomplished by skeletal traction or open reduction and internal fixation during a second procedure.

Vascular and uterine responses to dobutamine and dopamine in the gravid ewe.

Dopamine, a naturally occurring catecholamine precursor of norepinephrine, has been used in the treatment of cardiogenic shock. Following intravenous administation it increases cardiac output, blood pressure, and renal blood flow. Dobutamine is a directly acting inotropic agent which increases myocardial contractility without significantly changing blood pressure. This study was devised to compare the effects of these two drugs on uterine blood flow (UBF), uterine tonus (UT), mean arterial blood pressure (MAP), and heart rate (HR). Chronically instrumented pregnant ewes near term were infused with differet concentrations of dopamine and dobutamine while HR, MAP, UT and UBF were recorded continuously. Dopamine produced a decrease in UBF and an increase in MAP and UT while the HR response was variable. Dobutamine administration resulted in a marked increase in HR and a decrease in UBF, while MAP and UT remained essentially unchanged. Uterine vascular resistance increased with both drugs during high-dosage administration, but the rise was more pronounced following dopamine infusion. Since dobutamine exhibits less alpha-adrenergic activity than dopamine this drug would seem to be preferred when an inotropic agent is required for treatment of the pregnant patient.

Relationship of lesion size to survival in patients with stage IB squamous cell carcinoma of the cervix uteri treated by radiation therapy.

Forty-five patients with Stage IB squamous cell carcinoma of the cervix uteri were treated with radiation therapy alone. The five year actuarial survival rate of the 22 patients in group 1 in whom the tumor was less than 4 centimeters in diameter was 95 per cent, which was significantly higher than the 67 per cent survival rate in the 23 patients in group 2 with bulky lesions greater than or equal to 4 centimeters in diameter, p less than 0.05. These results of radiation therapy are consistent with surgical results recently reported and indicate that patients with bulky lesions, especially those tumors greater than or equal to 4 centimeters in size, comprise a high risk subset within the Stage IB classification. A new classification is proposed in which bulky lesions are designated Stage IC, advanced overt, so that such high risk patients might be identified and more efficacious treatment regimens might be developed.

Combination chemotherapy with and without the methanol-extracted residue of bacillus Calmette-Guerin (MER) in extensive non-small-cell lung cancer: a prospective randomized study for the Piedmont Oncology Association.

One-hundred-three patients with extensive non-small-cell lung cancer were entered into a prospective, randomized trial to determine the value of MER as an adjuvant to chemotherapy. Patients were stratified according to histology and performance status. All patients received CCNU, methotrexate, and Adriamycin with 48 patients also receiving MER. All patients had a performance status of 2 or less (less than 50% bedridden), 49% had prior radiation therapy, only one patient had prior chemotherapy, and all had extensive disease. Of the patients, 42% had epidermoid cancer, 21% had large cell cancer, 32% had adenocarcinoma, and 4% had mixed adenosquamous or undifferentiated carcinoma. The response rates and response durations of the two treatment regimens were similar. Of the patients, 18% had an objective response; in 4% it was complete. An additional 29% had a stable response. Median duration of response ranged from 21 to 23 weeks. Median survival rates for non-MER and MER treatment groups were 21.5 and 18.6 weeks, respectively. The four complete responders have a survival of 24, 85, 86+, and 129 weeks. MER did not improve response for hematopoietic tolerance, was associated with significant morbidity, and was poorly tolerated. The value of immunotherapy in lung cancer remains to be established.

A randomized comparative trial of chemotherapy and irradiation therapy for stage II breast cancer.

One hundred fifty-eight evaluable patients with Stage II carcinoma of the breast with positive lymph nodes were treated either with adjuvant chemotherapy or irradiation therapy followed by chemotherapy. Patients were randomized to test the effectiveness of L-phenylalanine mustard (L-PAM) with and without postoperative irradiation therapy (R.T.) against cyclophosphamide, 5-fluorouracil, and methotrexate (CMF) with and without postoperative irradiation therapy in decreasing the frequency of recurrence. No significant difference was observed between L-PAM as compared with R.T. plus L-PAM (P = 0.85). The difference between CMF and R.T. plus CMF was significant in support of CMF alone (P = 0.04). The frequency of recurrence between R.T. plus L-PAM and R.T. plus CMF showed no difference. A comparison of the chemotherapy only regimens showed an advantage of CMF over L-PAM (P = 0.05). Both the delay in starting chemotherapy and the significant decrease in percent optimal drug dosage during the first six cycles of therapy are factors that may influence the high frequency of relapse observed in the R.T. plus chemotherapy groups. Of the four treatments, CMF has the lowest frequency of recurrence.

Chemotherapy vs. chemoimmunotherapy with methanol extraction residue of Bacillus Calmette-Guerin (MER) in advanced breast cancer: a randomized trial by the Piedmont Oncology Association.

Effects of the addition of MER, a nonspecific, nonviable immunostimulant, to two combination chemotherapy programs were explored in patients with metastatic breast cancer. Patients were randomized to either CDVFP [cyclophosphamide (C), doxorubicin (D), vincristine (V), fluorouracil (F) and prednisone (P)] or CD alternating with methotrexate (M) and F (CD/MF). Each group was also randomized to receive MER, 0.4 mg S.C. every four weeks or no immunotherapy. The response rates were CDVFP 56%, CDVFP + MER 54%, CD/MF 43%, and CD/MF + MER 43%. No significant differences were noted in response rate. Median durations of response and survival were similar for each group: CDVFP 16.2 and 25.2 months, respectively; CDVFP + MER 14.0 and 23.3 months, CD/MF 12.1 and 26.1 months, and CD/MF + MER 15.5 and 25.6 months. Patients who achieved CR frequently had soft-tissue disease (7/17) and patients with disease in 1 or 2 metastatic sites had a significantly higher response rate than those in greater than or equal to 3 sites. MER did not enhance response rate, duration of response, or survival. Also MER did not diminish myelosuppression.