Steven R. Garfin

New technologies in spine: kyphoplasty and vertebroplasty for the treatment of painful osteoporotic compression fractures.

Study Design Literature review Objectives To describe new treatments for painful osteoporotic compression fractures in light of available scientific literature and clinical experience. Summary of Background Data. Painful vertebral osteoporotic compression fractures lead to significant morbidity and mortality. This relates to pulmonary dysfunction, eating disorders (nutritional deficits), pain, loss of independence, and mental status change (related to pain and medications). Medications to treat osteoporosis (primarily antiresorptive) do not effectively treat the pain or the fracture, and require over 1 year to reduce the degree of osteoporosis. Kyphoplasty and vertebroplasty are new techniques that help decrease the pain and improve function in fractured vertebrae. Methods. This is a descriptive review of the background leading to vertebroplasty and kyphoplasty, a description of the techniques, a review of the literature, as well as current ongoing studies evaluating kyphoplasty. Results Both techniques have had a very high acceptance and use rate. There is 95% improvement in pain and significant improvement in function following treatment by either of these percutaneous techniques. Kyphoplasty improves height of the fractured vertebra, and improves kyphosis by over 50%, if performed within 3 months from the onset of the fracture (onset of pain). There is some height improvement, though not as marked, along with 95% clinical improvement, if the procedure is performed after 3 months. Complications occur with both and relate to cement leakage in both, and cement emboli with vertebroplasty. Conclusion Kyphoplasty and vertebroplasty are safe and effective, and have a useful role in the treatment of painful osteoporotic vertebral compression fractures that do not respond to conventional treatments. Kyphoplasty offers the additional advantage of realigning the spinal column and regaining height of the fractured vertebra, which may help decrease the pulmonary, GI, and early morbidity consequences related to these fractures. Both procedures are technically demanding.

Harvesting autogenous iliac bone grafts: a review of complications and techniques

Autogenous bone grafts from the ilium are frequently harvested for purposes of bone union and/or stability. Although some donor site complications may be unavoidable, awareness of the anatomy and complications may aid in planning the approach and minimizing the risks. Documented donor site complications include pain, nerve and arterial injury, peritoneal perforation, sacroiliac joint instability, and herniation of abdominal contents through defects in the ilium. Strict observation of relevant anatomic considerations will help in avoiding these complications.

Early Failure of Long Segment Anterior Cervical Plate Fixation

A retrospective, multicenter study was undertaken to evaluate the early postoperative failure rate of long segment anterior cervical fusion and plating to stabilize the cervical spine after a two- or three-level corpectomy for degenerative, traumatic, and neoplastic diseases of the cervical spine. Patient demographic factors as well as technical factors such as bone graft placement, plate and screw position, and postoperative brace immobilization were analyzed. During the early postoperative period, the graft/plate construct dislodged in 3 of 33 patients with a two-level corpectomy and fusion (9%) compared with 6 of 12 patients with a three-level corpectomy and fusion (50%). The difference in failure rates after a three- versus two-level corpectomy and fusion was statistically significant (p < 0.05). A higher early failure rate was also seen with failure to correctly lock the screws to the plate and the use of a peg-in-hole type bone grafting technique, although these differences were not statistically significant. Although several technical and patient-specific factors may contribute to this, anterior cervical plating and bone grafting alone after a three-level cervical corpectomy for various spinal disorders appears to afford inadequate stability in the early postoperative period, regardless of immobilization methods.

Complications in the Use of the Halo Fixation Device

The medical records of 179 patients were reviewed to identify complications related to the use of the halo external skeletal-fixation device. The complications that were identified included pin-loosening in 36 per cent of the patients, pin-site infection in 20 per cent, pressure sores under either a plastic vest or a plaster cast in 11 per cent, nerve injury in 2 per cent, dural penetration in 1 per cent, dysphagia in 2 per cent, cosmetically disfiguring scars in 9 per cent, and severe pin discomfort in 18 per cent. One hundred and eighty (25 per cent) of the 716 pins used had become loose at least once, and an infection had developed at sixty-seven pin sites (9 per cent). Two-thirds of the pins that were loose or associated with infection required change or removal. These complication rates, particularly of pin-loosening and infection, are exceedingly high. Attention to details in pin application, pin maintenance, and proper pin-site care may minimize the number of complications.

Percutaneous balloon kyphoplasty for the correction of spinal deformity in painful vertebral body compression fractures

Vertebral body compression fractures can cause chronic pain and may result in progressive kyphosis. Although vertebroplasty has been used to treat pain, it does not attempt to restore vertebral body height and eliminate spinal deformity. Percutaneous balloon kyphoplasty is a novel technique, which involves the introduction of inflatable bone tamps into the fractured vertebral body for elevation of the endplates, prior to fixation of the fracture with bone cement. Our initial experience with this minimally invasive procedure indicates that percutaneous balloon kyphoplasty can be efficacious in the treatment of painful, osteoporotic vertebral compression fractures.

Perioperative Nutrition and Postoperative Complications in Patients Undergoing Spinal Surgery

Study Design The authors undertook a three‐part study to better understand the impact of perioperative nutritional status on postoperative complications in patients undergoing spinal surgery. In preliminary Parts I and II, the authors targeted two groups of patients who are particularly nutritionally challenged. In Part III, they studied a large group of consecutive patients undergoing routine lumbar spinal fusion. Objectives To determine whether preoperative nutritional status was a significant predictor of postoperative complications in patients undergoing elective lumbar spinal fusion. Summary of Background Data In Part I, 27 patients treated surgically for vertebral osteomyelitis were divided into two groups based on their preoperative nutritional status. Twenty‐four of the 26 postoperative complications were in the malnourished group (P < 0.001). In Part II, 15 (75%) of 20 patients treated surgically for spinal cord injury were found to become malnourished in the postoperative period. Seventeen complications were noted, all in the malnourished group (P = 0.001). Methods One hundred fourteen consecutive patients undergoing elective lumbar decompression and fusion were identified and their records reviewed. In addition to preoperative nutritional status, data gathered included age, sex, height, weight, past medical history, steroid use, alcohol use, tobacco use, type of bone graft (allograft vs. autograft), history of previous lumbar surgery, number of levels fused, and use of spinal instrumentation. Results Eleven of 13 postoperative infectious complications (10 deep wound infections) were noted in the malnourished group (P < 0.001). By stepwise logistic regression analysis, preoperative nutritional status was an extremely significant independent predictor of postoperative complications in patients undergoing elective lumbar spinal fusion (P = 0.0018). Conclusions The prevalence data in our study population suggest that a large number (25%) of patients undergoing elective lumbar spine surgery are nourished inadequately at surgery. This number is higher (42%) in older patients. The authors recommend that close attention be paid to the perioperative nutritional status of patients undergoing lumbar spinal surgery. Patients with suboptimal nutritional parameters should be supplemented and replenished before elective surgery.

A placebo-controlled randomized clinical trial of nortriptyline for chronic low back pain

&NA; To assess the efficacy of nortriptyline, a tricyclic antidepressant, as an analgesic in chronic back pain without depression, we conducted a randomized, double‐blind, placebo‐controlled, 8‐week trial in 78 men recruited from primary care and general orthopedic settings, who had chronic low back pain (pain at T‐6 or below on a daily basis for 6 months or longer). Of these 57 completed the trial; of the 21 who did not complete, four were withdrawn because of adverse effects. The intervention consisted of inert placebo or nortriptyline titrated to within the therapeutic range for treating major depression (50–150 ng/ml). The main outcome endpoints were pain (Descriptor Differential Scale), disability (Sickness Impact Profile), health‐related quality of life (Quality of Well‐Being Scale), mood (Beck Depression Inventory, Spielberger State Anxiety Inventory, Hamilton Anxiety/Depression Rating Scales), and physician rated outcome (Clinical Global Impression). Reduction in pain intensity scores was significantly greater for participants randomized to nortriptyline (difference in mean change 1.68, 95% −0.001, CI −3.36, P=0.050), with a reduction of pain by 22% compared to 9% on placebo. Reduction in disability marginally favored nortriptyline (P=0.055), but health‐related quality of life, mood, and physician ratings of overall outcome did not differ significantly between treatments. Subgroup analyses of study completers supported the intent‐to‐treat analysis. Also, completers with radicular pain on nortriptyline (n=5) had significantly (P<0.05) better analgesia and overall outcome than did those on placebo (n=6). The results suggest noradrenergic mechanisms are relevant to analgesia in back pain. This modest reduction in pain intensity suggests that physicians should carefully weigh the risks and benefits of nortriptyline in chronic back pain without depression.

Two-year fusion rate equivalency between Grafton DBM gel and autograft in posterolateral spine fusion: a prospective controlled trial employing a side-by-side comparison in the same patient.

Study Design. Multicenter, prospective equivalency trial with each patient serving as his/her own control. Objectives. To compare the effectiveness of a Grafton® DBM gel composite with iliac crest autograft in posterolateral spine fusion. Summary of Background Data. While autograft remains the preferred graft material to facilitate spine fusion, the supply is limited and harvesting produces undesirable clinical consequences. Methods. A total of 120 patients underwent posterolateral spine fusion with pedicle screw fixation and bone grafting. Iliac crest autograft was implanted on one side of the spine and a Grafton® DBM/autograft composite was implanted on the contralateral side in the same patient. An independent, blinded reviewer evaluated anteroposterior and lateral flexion-extension radiographs. The fusion mass lateral to the instrumentation on each side was judged fused or not, and the mineralization of the graft was rated absent, mild, moderate, or extensive. The degree of correspondence in outcomes between sides was estimated by computing the percentage agreement and kappa statistic. Results. Nearly 70% of patients (81 of 120) provided complete 24-month radiographic studies. The bone graft mass was fused in 42 cases (52%) on the Grafton® DBMside and in 44 cases (54%) on the autograft side. The overall percentage agreement for fusion status between sides was approximately 75% (61 of 81), indicating moderately strong statistical correspondence (kappa = 0.51, P < 0.0001). Bone mineralization ratings also were similar between treated sides. Perfect agreement was realized in almost 60% of patients (48 of 81) with moderate statistical correspondence (weighted kappa = 0.54, P < 0.0001). Conclusions. Grafton® DBM can extend a smaller quantity of autograft than is normally required to achieve a solid spinal arthrodesis. Consequently, a reduced amount of harvested autograft may be required, potentially diminishing the risk and severity of donor site complications.

Architectural Analysis and Intraoperative Measurements Demonstrate the Unique Design of the Multifidus Muscle for Lumbar Spine Stability

BACKGROUND Muscular instability is an important risk factor for lumbar spine injury and chronic low-back pain. Although the lumbar multifidus muscle is considered an important paraspinal muscle, its design features are not completely understood. The purpose of the present study was to determine the architectural properties, in vivo sarcomere length operating range, and passive mechanical properties of the human multifidus muscle. We hypothesized that its architecture would be characterized by short fibers and a large physiological cross-sectional area and that it would operate over a relatively wide range of sarcomere lengths but would have very stiff passive material properties. METHODS The lumbar spines of eight cadaver specimens were excised en bloc from T12 to the sacrum. Multifidus muscles were isolated from each vertebral level, permitting the architectural measurements of mass, sarcomere length, normalized fiber length, physiological cross-sectional area, and fiber length-to-muscle length ratio. To determine the sarcomere length operating range of the muscle, sarcomere lengths were measured from intraoperative biopsy specimens that were obtained with the spine in the flexed and extended positions. The material properties of single muscle fibers were obtained from passive stress-strain tests of excised biopsy specimens. RESULTS The average muscle mass (and standard error) was 146 +/- 8.7 g, and the average sarcomere length was 2.27 +/- 0.06 microm, yielding an average normalized fiber length of 5.66 +/- 0.65 cm, an average physiological cross-sectional area of 23.9 +/- 3.0 cm(2), and an average fiber length-to-muscle length ratio of 0.21 +/- 0.03. Intraoperative sarcomere length measurements revealed that the muscle operates from 1.98 +/- 0.15 microm in extension to 2.70 +/- 0.11 microm in flexion. Passive mechanical data suggested that the material properties of the muscle are comparable with those of muscles of the arm or leg. CONCLUSIONS The architectural design (a high cross-sectional area and a low fiber length-to-muscle length ratio) demonstrates that the multifidus muscle is uniquely designed as a stabilizer to produce large forces. Furthermore, multifidus sarcomeres are positioned on the ascending portion of the length-tension curve, allowing the muscle to become stronger as the spine assumes a forward-leaning posture.

Subjective sleep disturbance in chronic back pain

Although disturbed sleep is thought to be common in patients with chronic low back pain, little data systematically address this issue. We administered a self-report inventory of sleep performance to an unselected sample of chronic low back pain patients (n= 51) attending a general orthopedic clinic. Approximately 50% (n= 26) of the group experienced poor sleep. Self-reported dissatisfaction with sleep was more strongly associated with more depressed mood and with shorter pain chronicity than with medical evidence of orthopedic disease. Patients with high pain intensity reported significantly less sleep time, more delayed sleep onset, and more nighttime awakenings than did patients with low pain intensity. Overnight polysomnography in a subsample of seven depressed and nondepressed patients with poor sleep revealed abnormalities in a proportion of these subjects, including reduced total sleep time, decreased or absent Stage 3 and 4 sleep, shortened time to onset of rapid eye movement sleep, and periodic leg movements in sleep. Sleep complaints appear to be common in back pain patients and may reflect diverse sleep anomalies. The pathophysiology of these disturbances may be related to pain complaint, affective distress, or independent sleep disorders.