Yossi Smorgick

Accuracy and safety of thoracic pedicle screw placement in spinal deformities.

Objectives: To determine the safety of pedicle screw fixation in thoracic spine deformity correction. Methods: One hundred twelve pedicle screws were surgically placed in 25 patients with degenerative, posttraumatic, and Scheuermann kyphosis and idiopathic and neuromuscular scoliosis. Screw position was evaluated using intraoperative and postoperative radiographs and thin-slice computed tomography. Results: Of the total 112 thoracic pedicle screws that were inserted, 98 screws (87.5%) were fully contained within the cortical boundaries of the pedicle. When comparing proximal screws (T1-T8) with distal screws (T9-T12) and convex placed screws with concave ones, a statistically significant difference in screw placement was evident (P < 0.05). More misplaced screws were seen proximally and on the concave side. Of the 14 malpositioned screws, 2 (1.8%) demonstrated aortic abutment. There were no neurologic deficits, vascular injuries, or mechanical failures recorded. Conclusions: Placement of thoracic pedicle screws is both feasible and safe.

Failure of the Wallis interspinous implant to lower the incidence of recurrent lumbar disc herniations in patients undergoing primary disc excision.

Background Ipsilateral recurrent disc herniation after lumbar discectomy is a significant problem in the management of lumbar disc disease and may necessitate repeat surgical intervention. A population-based study in Finland found that about 14% of all primary lumbar discectomies required additional surgical interventions. Interspinous devices, which have been shown to unload the posterior anulus, may reduce the occurrence of recurrent herniations. We report our short-term experience with the use of the Wallis device in the management of patients with lumbar disc herniation undergoing primary disc excision. Patients and Methods Thirty-seven consecutive patients (23 males and 14 females, average age 36 y) underwent primary lumbar disc excision followed by fixation of the segment with the Wallis implant during a period of 1 year. Indications for implanting the Wallis device were a voluminous disc herniation and preservation of at least 50% of disc space height. Surgery was performed at level L4-5 in most patients. Average follow-up after surgery was 16 months (range 12 to 24). The last 14 patients were also evaluated by the preoperative and postoperative Oswestry Disability Index (ODI) questionnaire, the SF-36 survey, and by a visual analog scale (VAS) for back and leg pain. Results The average ODI dropped from 43 to 12.7. The average VAS for back pain dropped from 6.6 to1.4 and the average Vas for leg pain dropped from 8.2 to 1.5. Five patients (4 males and 1 female) with relapsing leg pain were diagnosed by contrast-enhanced magnetic resonance imaging as suffering from recurrent herniation (5/37, 13%). All reherniations occurred at level L4-5 level between 1 and 9 months after the index surgery. Two of the 5 patients subsequently underwent additional discectomy and fusion. Summary The current Wallis implant is probably incapable of reducing the incidence of recurrent herniations, but it still may be useful in patients with discogenic back pain due to early degenerative disc disease.

Management of deep wound infection after posterior lumbar interbody fusion with cages.

Objectives To evaluate long-term treatment outcome of patients with infected posterior lumbar interbody fusion (PLIF) managed with surgical debridement and or prolonged antiobiotic treatment without removal of the interbody cages. Methods Between 1996 and 1999, 8 out of 111 patients who underwent PLIF were diagnosed with deep wound infection (7.2%). All infected patients were clinically followed for at least 2 years after completion of the antibiotic treatment. Longer follow-up of at least 6 years duration was performed by a telephone interview. Results Six patients were managed with surgical debridement, wound irrigation, and primary closure of the wound. None of the patients required removal of the instrumentation. In 2 patients, the PLIF cages were repositioned in the face of infection. All 8 patients received 4 to 6 weeks of intravenous antibiotic therapy followed by another 6 to 9 weeks of oral antibiotic administration. At 2-year follow-up, no clinical or laboratory signs of recurrent infection were evident. Four of the 8 patients reported improved clinical status compared with their prefusion status. At 6-year follow-up, 3 patients had minimal disability according to the Oswestry Disability Index and 2 patients had moderate disability with residual leg pain. Conclusions In cases of postoperative deep wound infection after PLIF with cages, removal of the interbody implants is not necessary. Treatment is composed of prolonged antibiotic therapy guided by antimicrobial susceptibility of the isolated bacteria and supplemented with extensive surgical debridement if needed.

Single- versus multilevel fusion for single-level degenerative spondylolisthesis and multilevel lumbar stenosis: four-year results of the spine patient outcomes research trial.

Study Design. A subanalysis study. Objective. To compare surgical outcomes and complications of multilevel decompression and single-level fusion with multilevel decompression and multilevel fusion for patients with multilevel lumbar stenosis and single-level degenerative spondylolisthesis (DS). Summary of Background Data. In patients with DS who are treated surgically, decompression and fusion provide a better clinical outcome than decompression alone. Surgical treatment for multilevel lumbar stenosis and DS typically includes decompression and fusion of the spondylolisthesis segment and decompression with or without fusion for the other stenotic segments. To date, no study has compared the results of these 2 surgical options for single-level DS with multilevel stenosis. Methods. The results from a multicenter randomized and observational study, the Spine Patient Outcomes Research Trial comparing multilevel decompression and single-level fusion and multilevel decompression and multilevel fusion for spinal stenosis with spondylolisthesis, were analyzed. The primary outcome measures were the bodily pain and physical function scales of the Medical Outcomes Study 36-item Short-Form General Health Survey (SF-36) and the modified Oswestry Disability Index at 1, 2, 3, and 4 years postoperatively. Secondary analysis consisted of stenosis bothersomeness index, low back pain bothersomeness, leg pain, patient satisfaction, and self-rated progress. Results. Overall, 207 patients were enrolled for the study, 130 had multlilevel decompression with 1 level fusion and 77 patients had multilevel decompression and multilevel fusion. For all primary and secondary outcome measures, there were no statistically significant differences in surgical outcomes between the 2 surgical techniques. However, operative time and intraoperative blood loss were significantly higher in the multilevel fusion group. Conclusion. Decompression and single-level fusion and decompression and multilevel fusion provide similar outcomes in patients with multilevel lumbar stenosis and single-level DS.

Long-term results of proximal femoral osteotomy in Legg-Calvé-Perthes disease.

Background: Legg-Calvé-Perthes disease is a childhood hip disorder that may result in a deformed and poorly functioning hip. The purpose of this study was to evaluate the correlation between hip deformity at skeletal maturity and degenerative osteoarthritis and to present the long-term results of proximal femoral varus derotational osteotomy in Legg-Calvé-Perthes disease. Methods: We analyzed the results of 40 patients (43 hips), who underwent proximal femoral varus derotational osteotomy for Legg-Calvé-Perthes disease in our institution between 1959 and1983. All available patients underwent a single long-term follow-up examination. Hips were classified with the classification system of Stulberg. Osteoarthritis was evaluated using the Tönnis classification. The long-term outcomes were evaluated after a mean follow-up period of 33 years. Results: When examining the outcome using the Stulberg classification system, there were 8 Stulberg class I hips (19.5%), 15 Stulberg class II hips (36.6%), 8 Stulberg class III hips (19.5%), 9 Stulberg class IV hips (22%), and 1 Stulberg class V hip (2.4%). One patient, who had a bilateral Legg-Calvé-Perthes disease, underwent total hip replacement for osteoarthritis. Seven patients had poor clinical results. Conclusions: Proximal femoral varus derotational osteotomy provides good long-term results for Legg-Calvé-Perthes disease. The Stulberg classification is a good predictor for patient outcome. Level of Evidence: Level IV, therapeutic study.

Instrumented slip reduction and fusion for painful unstable isthmic spondylolisthesis in adults.

Background Context Although in situ posterolateral fusion is considered the gold standard for surgical treatment of low-grade adult spondylolisthesis, correction of the sagittal translation by instrumented slip reduction is more controversial in adults; nevertheless it may delay adjacent level disc degeneration. Purpose The present study was undertaken to evaluate the safety and clinical outcome of operative instrumented slip reduction in 12 adults with isthmic spondylolisthesis accompanied by advanced disc degeneration at that level. Study Design This study was a retrospective review of 12 consecutive lumbar or lumbosacral isthmic slip, which underwent operative slip reduction in our institute. Patient Sample All adult patients having operative instrumented slip reduction of isthmic spondylolisthesis from January 2000 to December 2005 were assessed. Outcome Measures Outcome measures included the Oswestry Disability Index (ODI) for low back pain and the visual analog scale (VAS) of back and leg pain. Patient outcome was assessed by work status, participation in sports activities and intake of pain medications. Methods Between January 2000 and December 2005, we performed slip reduction on 12 adults aged 28 to 62 years (average 47) with symptomatic lumbar or lumbosacral isthmic spondylolisthesis. The indications for surgery were long-standing low back and leg pain that had not responded to nonoperative management. Results The vertebral slip ranged between 15% and 90% (average 34%). Radiologic evidence of adult slip progression was available in 5 patients, one had a de novo slip formation and the others had increased sagittal translation on flexion-extension lateral x-rays. All 12 patients underwent posterior decompression, pedicle screw fixation, slip reduction, and posterior lumbar interbody fusion. The slip was anatomically reduced by 100% in 5 patients and between 90% and 95% in 7 (average 95% for the group). X-rays revealed no evidence of instrumentation failure at a mean follow-up of 38 months (range: 18 to 72). Minimal loss of correction (5%) was observed in 2 cases. No neurologic complications were encountered. The mean preoperative ODI of 49 dropped to 12 postoperatively (range: 0 to 20). The mean preoperative VAS for back pain of 7.3 dropped to 1.6 after surgery (range: 0 to 3). The mean preoperative VAS for leg pain of 8 dropped to 1 after surgery (range: 0 to 4). Five patients were followed for more than 3 years: none had evidence of adjacent level disc disease. Conclusions Our results may support performing slip reduction in selected adults with isthmic spondylolisthesis.

Predisposing factors for dural tear in patients undergoing lumbar spine surgery

OBJECT The purpose of this prospective cohort study was to identify risk factors for incidental durotomies in lumbar spine surgery. The authors hypothesized that the incidence of durotomy would be higher in cases involving multiple operations. METHODS The authors prospectively evaluated 523 patients who underwent lumbar and thoracolumbar spine surgery. They compared data on patients in whom a dural tear occurred and those in whom a dural tear did not occur. Data from patients in whom a dural tear occurred were compared with data from patients who did not experience durotomy. The data included basic demographic information, intraoperative data, and clinical information from a medical record review. RESULTS One hundred thirty-one patients underwent discectomy and 392 patients underwent laminectomy. Among the 131 patients who underwent discectomy 6 patients had a dural tear. Among the 392 patients who underwent discectomy 49 patients had dural tear. Patients with incidental durotomy were older (mean 65 ± 13 vs 60 ± 14 years of age; p = 0.044, t-test), and had longer surgery (146 ± 59 vs 110 ± 54 minutes; p = 0.025, t-test), compared with the patients without dural tear. The incidence of dural tear was more common in patients with a history of previous spine surgery (p < 0.001). CONCLUSIONS In patients who underwent lumbar and thoracolumbar spine surgery for degenerative problems, previous surgery and older age were found to be predisposing factors for dural tear.

Predictors of back pain in adolescent idiopathic scoliosis surgical candidates.

Background: There are contradictory reports on the overall prevalence of back pain in the adolescent population compared with adolescent idiopathic scoliosis (AIS) patients. Most reports do not investigate pain in patients with AIS but try to identify in which subgroup of patients with AIS an underlying pathology should be excluded. The objective of this study was to find whether AIS in operative candidate patients is a painful condition and to try and find clinical and radiologic predisposing factors, which will help us to predict patients who are going to have pain. Methods: Candidates who had to undergo an operative treatment for AIS between October 2004 and October 2009 in our institution, were enrolled to the study. Pain was graded with the use of visual analogue scale (VAS) on a scale from 0 to 10. We recorded the age at presentation, sex, menarchal status, family history of scoliosis, brace treatment history, and neurological findings. Radiologic parameters recorded were: the type of curve according to the Lenke classification, Cobb angle, thoracic kyphosis angle, apex vertebra rotation, Risser grade, coronal balance, and curves flexibility. Results: Seventy patients with AIS were included in this study. Fifty patients (71%) reported of some kind of back pain with 34 patients (48%) grading their pain as ≥5 on the VAS. Patients in whom scoliosis was diagnosed in older age and patients with a more rigid lumbar curve had statistically significant higher VAS scores (P=0.014, P=0.036). Patients who were treated with a brace had a statistically significant lower VAS scores (P=0.019). Conclusions: Back pain is common in patients with AIS who are candidates for operative treatment. The following parameters correlate with worse back pain: older age at diagnosis, no use of brace, and rigid lumbar curve. Level of Evidence: Type III.

Spontaneous ligamentum flavum hematoma in the lumbar spine

Lumbar or sacral nerve root compression is most commonly caused by intervertebral disc degeneration and/or herniation. Less frequently, other extradural causes may be implicated, such as infection, neoplasm, epidural hematoma, or ligamentum flavum pathology. We present the case of a patient with spontaneous ligamentum flavum hematoma compressing the L4 nerve root, without antecedent trauma. Although exceedingly rare, the diagnosis of ligamentum flavum pathology in general, and that of ligamentum flavum hematoma in particular, should be considered on those rare occasions when the etiology of lumbar or sacral nerve root compressions appears enigmatic on radiological studies. Usually surgical treatment produces excellent clinical outcome.

Spinal cord position in adolescent idiopathic scoliosis.

Background: The use of thoracic pedicle screws in deformity surgery provides a stable fixation system. The concept of acceptably positioned screws includes a worrisome subset of screws that perforate the medial pedicle cortex and may result in some compromise of the spinal canal. A significant higher incidence of cortical wall penetration on the concave side compared with the convex was previously found. Although several authors assumed that the spinal cord hugs the concave pedicles when the spinal deformity is scoliosis, the position of spinal cord in adolescent idiopathic scoliosis (AIS) has not been studied in depth. Methods: We reviewed 45 patients who were candidate for operative treatment for AIS between August 2007 and October 2010 at our institution. Posteroanterior and lateral 3-ft standing preoperative radiographs of the spine were reviewed to determine: Cobb angle of the thoracic curves, apex vertebra of the curves, and end vertebras of the curves. Magnetic resonance images were retrospectively reviewed. The lateral cord space (LCS) ratio, which reflects the relative position of the spinal cord in the spinal canal, was calculated for each level with a thoracic curve. Results: The average LCS for thoracic curves of >50 degrees was 2.123. The average LCS for thoracic curves of <50 degrees was 1.551 (P=0.002). The LCS for the apex vertebra was 1.699. The LCS for the upper end vertebra and lower end vertebra were 1.212, 1.225, respectively (P<0.001). There was a statistically significant difference between right thoracic curves and left thoracic curve regarding the LCS. In right thoracic curve the LCS was 1.487 (1.487+0.45) while in left thoracic curve it was 0.761 (0.761+0.17) meaning that in both curves the spinal cord moved to the concave side of the curve. Conclusions: Our study confirms that spinal cord in AIS tend to follow the appearance of the curve with its being tethered on the concave side. The spinal cord is close to the pedicle around the apex area.