5.5-mm Cobalt-Chrome vs 6-mm Titanium Alloy Rods in Surgical Treatment of Lenke 1 Adolescent Idiopathic Scoliosis With High-Density Pedicle Screws and Direct Vertebral Rotation on Differently Shaped Rods: A Retrospective Comparative Cohort Study.

BACKGROUND: The gold standard of surgical treatment of adolescent idiopathic scoliosis (AIS) consists of a posterior approach requiring complex 3-dimensional correction with multisegmental pedicle screws and 2 contoured rods. The substantial corrective forces and the ability of the rod to withstand these forces rely on its biomechanical properties. The aim of this study is to compare outcomes of 5.5-mm cobalt-chrome (CoCr) and 6-mm titanium alloy (TiAl) rods in surgical correction in Lenke 1 AIS patients. TiAl has greater elasticity, which may facilitate the correction maneuver, whereas the stiffness of CoCr may result in stronger correction forces. The literature provides no clear indications about which rod may allow better correction and safety. METHODS: A total of 64 consecutive patients (30 CoCr vs 34 TiAl) with Lenke 1 AIS <100°, with 2 years minimum follow-up, requiring correction and posterior fusion at our institution were included. The primary outcome measure was coronal and sagittal correction and loss of correction at 2-year follow-up. Secondary outcome measures compared peri- and postoperative complications. RESULTS: The mean coronal correction was higher in the CoCr group: -73.6% ± 7.4 vs -65.5% ± 11 (P = 0.001). Mean T5-T12 kyphosis did not change significantly after surgery. In patients with hypokyphosis (<10°), an improvement in thoracic kyphosis was observed in both groups, but the improvement was significantly higher in the TiAl group (P = 0.038). In patients with hyperkyphosis (>40°), a similar reduction in thoracic kyphosis was observed in both groups. At follow-up, no coronal correction loss occurred. The sagittal correction loss was slight (0.5° ± 1.5 for the CoCr group, 1.5° ± 3 for the TiAl group) but statistically higher in the TiAl group (P = 0.032). There were no mechanical complications. One revision was required for infection in the CoCr group. CONCLUSION: In this series of Lenke 1 AIS, with the limitations of the study, 5.5-mm CoCr rods have provided better correction in the coronal plane than 6-mm TiAl rods. However, TiAl rods have been found to be associated with higher increase of thoracic kyphosis in hypokyphotic curves, although the clinical relevance of this finding could be questionable. CLINICAL RELEVANCE: This article provides surgeons with more information regarding rod material options when correcting Lenke 1 AIS.

Spine Infections: The Role of Fluorodeoxyglucose Positron Emission Tomography (FDG PET) in the Context of the Actual Diagnosis Guideline.

Spondylodiscitis is an infectious process that requires numerous health care professionals to be clearly diagnosed and eventually successfully treated. It implies a variety of microbiological agents and conditions; during the diagnostic workup, it is difficult to correctly identify them, and the clinician has to rapidly choose the correct treatment to avoid permanent injuries to the patient. In this context, we conducted a review to better understand the most suitable use of Positron Emission Tomography with 18-Fluoro-deossi-glucose (FDG PET) in a patient suspected of spondylodiscitis, based on current guidelines and literature.. We wanted to review the role of FDG PET in the spondylodiscitis diagnosis and follow up in the context of the current guidelines.

Does use of pre-operative low-dose CT-scan in adolescent idiopathic scoliosis improve accuracy in screw placement? Results of a retrospective study.

PURPOSE: To evaluate the efficacy of pre-operative low-dose radiation computed tomography (CT) in optimizing screw placement in patients with adolescent idiopathic scoliosis (AIS). METHODS: 49 patients with AIS who required correction and posterior fusion between January 2018 and December 2019 were included in this retrospective study. All patients underwent surgery performed by the same team of experienced surgeons. Patients were divided in two groups. The study group received a pre-operative low-dose CT scan (CT group, n = 25), differently from the control group (CG, n = 24). Patients of both groups received a post-operative low-dose CT scan. The primary outcome measure was the accuracy of screw placement on the Gertzbein-Robbins scale (grades A and B were considered acceptable). Secondary outcome measures included a comparison of perioperative complications. RESULTS: A total of 1045 screws were placed. In CT group (n = 25, screws = 528) and CG (n = 24, screws = 517), trajectories were grade A or B in 94.5% and 93.6% of screws, respectively. Two screws (one for each group) were removed because of intra-operative-evoked potentials alteration and one screw required revision after post-operative imaging. No correlation was found between the malpositioning rate and the proximity to the apex of the curve, conversely a significative peak of misplacements was observed at T3 (p < 0.01). No neurological and vascular complications related to screw placement were recorded. There was not intergroup difference neither in screw accuracy (Chi-Square, 2-tailed Fisher's exact, p = 0.63), nor in complications rate. CONCLUSION: Pre-operative low-dose CT scan as surgical plan does not contribute in reducing pedicle screw misplacement rate. STUDY DESIGN: Retrospective comparative cohort study. LEVEL OF EVIDENCE: III.

Copper-Alloy Surfaces and Cleaning Regimens against the Spread of SARS-CoV-2 in Dentistry and Orthopedics. From Fomites to Anti-Infective Nanocoatings.

The latest diffusion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the coronavirus disease (COVID-19), has involved the whole world population. Even if huge efforts to control the pandemic have been done, the viral spread is still continuing. COVID-19 is reported as a zoonosis jumped from bats and pangolins to humans. After infection in humans, SARS-CoV-2 is found in the nasopharyngeal and salivary secretions. The virus has also been detected in the blood plasma of infected patients. The viral spread occurs through droplets exhaled from the nose and mouth of the infected people when they breath or talk, or through droplets propelled as a dense cloud by chough or sneeze. The virus can also be delivered as an aerosol from blood plasma, through surgical procedures. Following these ways, the virus can disperse in the air, then reaching and settling on the exposed surfaces. How long the virus will survive on a surface depends on the material the surface is made from. Infection via high-touch surfaces should be prevented. Copper alloy coatings, combined with efficient hygienic/disinfectant procedures and careful surgical practice, could be helpful to health protection in dental practice and can also be adopted in orthopedic traumatology.

Severe adolescent idiopathic scoliosis: posterior staged correction using a temporary magnetically-controlled growing rod.

PURPOSE: A two-staged posterior correction, using a temporary magnetically controlled growing rod (MCGR), was employed to gradually and safely correct severe adolescent idiopathic scoliosis (AIS). The aim of the study is illustrating the results of this procedure. METHODS: A retrospective review of a consecutive series of 17 severe AIS. The first surgery was a posterior release (multiple Ponte osteotomies) with implant of pedicle screws and MCGR on the concave side of the curve. In post-operative days, a distraction was applied with MCGR, which allowed to obtain a total mean lengthening of 2 cm in about 2 weeks, with no complications arising. In the second posterior surgery, MCGR was removed and the definitive rods were applied for final fusion. The mean pedicle screws density was 93.3% (85-100). The extension of the final posterior fusion-instrumentation was of 13.8 levels (12-15). RESULTS: At an average follow-up (FU) of 2.9 years, the main scoliosis curves from average pre-operative Cobb angle of 98.2° (91°-138°) bent down to 38.3° (35°-76°) after definitive fusion (p < 0.05); at last FU, the overall correction was 58.7% (50.4-71.2), with an average correction loss of 2.1° (1.5°-3.1°). At last FU, no complications were reported. CONCLUSIONS: Gradual traction with MCGR in severe AIS proved to be a safe method to achieve progressive curve correction before posterior final fusion, with no neurologic complications associated to more aggressive one-stage surgeries. In a staged approach, MCGR appears as an alternative to halo traction, avoiding frequent traction-related complications.

Liver and skeletal muscle injury in a 12-year-old female patient after scoliosis correction in prone position: a case report.

We report the case of a 12-year-old female, otherwise healthy patient, who underwent surgery for scoliosis correction in prone position under total intravenous general anesthesia, with CardioQ and sensory-motor-evoked potentials for hemodynamic and neurological monitoring. The patient showed severe intraoperative hypotension, lactic acidosis, and complete abolition of motor-evoked potentials during the positioning of posterior corrective bars. During the postoperative period, the increase in muscle and liver enzymes indicated an abdominal organ damage and confirmed hypoperfusion of the lower limbs. Both side effects were caused by the malposition of the patient on the operating table. The case resolved within the first postoperative week without sequelae.

High grade isthmic spondylolisthesis; can reduction always re-align the unbalanced pelvis?

BACKGROUND: Recently, various studies have reported the importance of distinguishing between balanced and unbalanced SL, sustaining the importance of SL reduction in unbalanced cases. In this study we present our experience in the treatment of isthmic spondylolisthesis in young patients, observing the correlation between SL reduction and sagittal correlation between spine and pelvis. METHODS: This is a retrospective study of a series of patients treated surgically for isthmic spondylolisthesis. Inclusion criteria were L5-S1 isthmic spondylolisthesis of III° or IV°, pediatric age, clinical and radiographic follow up of at least 1 year. Radiographic evaluation included the following elements: grade and percentage of listhesis (%L), lumbar lordosis (LL), lumbar-sacral angle (LSA), pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT) distinguishing between "balanced" and "unbalanced" patients. Radiographic values were confronted by using Student's t- test, obtaining a statistically significant difference for values inferior to 0,05. RESULTS: Based on inclusion criteria, 28 patients were selected for our retrospective analysis, 19 female and 9 male. Mean age at surgery was 15,6 years. Mean follow up was 3 years and 3 months (min. 1 year - max 6 years and 7 months). Spondylolisthesis reduction was statistically significant both in balanced and in unbalanced patients, but pelvic incidence values did not improve significantly. We observed fewer mechanical complications in patients treated with interbody support. CONCLUSION: In our study, differences between pre-op and post-op spinopelvic alignment values were not statistically significant, even though spondylolisthesis reduction was statistically significant in all cases. Our study could be considered an initial attempt to correlate spinopelvic changes to spondylolisthesis reduction in a progressive manner, and possibly in the future, generate threshold values of reduction for ideal spinopelvic alignment in every different patient.

Vertebroplasty in the treatment of osteoporotic vertebral compression fractures: patient selection and perspectives.

Osteoporotic vertebral fractures represent a constantly increasing pathology that may compromise life quality and general health. Among various treatment options, percutaneous vertebroplasty has been used widely over the past 20 years. Although there is a vast amount of retrospective reports in the literature, high-level evidence has emerged only recently. In this paper, the authors provide a synopsis of the current literature on the efficacy and safety of percutaneous vertebroplasty while also presenting a step-by-step description of the surgical procedure, focusing on details that may help in optimizing quality and safety.

Acute pancreatitis after major spine surgery: a case report and literature review.

BACKGROUND: Acute pancreatitis has been described as potential complication of both abdominal and non-abdominal surgeries. The pathogenetic mechanism underlying acute pancreatitis in spine surgery may include intraoperative hemodynamic instability causing prolonged splanchnic hypoperfusion, as well as mechanical compression of the pancreas due to scoliosis correction, with a higher risk in cases of more extended fusions, especially in young adults with lower body mass index (BMI). CASE PRESENTATION: We report here a case of postoperative acute pancreatitis with benign evolution in a young female patient after the first and second surgery of a two-stage correction of right thoracic idiopathic scoliosis.In December 2017, the patient underwent first-stage T4-L3 posterior arthrodesis with T7-T12 osteotomies and temporary magnetic bar. Intraoperative blood loss required massive transfusion. In the immediate postoperative period, the patient started reporting nausea/vomiting, abdominal pain at pressure, moderate meteorism, abdominal distension, hypoactive bowel sounds, and fever. Laboratory tests indicated a progressive increase in aspartate aminotransferase, alanine aminotransferase, serum amylase, lipase, phospho-creatine kinase, and reactive C-protein. A CT scan showed free abundant abdominal fluid in the hepatic, renal, pancreatic, and pelvic regions. After the diagnosis, a hypolipidic diet was initiated, and good hydration per os was maintained. After gastroenterologic consultation, somatostatin, rifaximin, and ursodehoxycholic acid were initiated and maintained for 8 days. In the following days, laboratory tests showed a slow but consistent decrease in liver and pancreatic enzymes until normalization. In January 2018, the patient underwent second-stage surgery with removal of magnetic bar, definitive posterior fusion, and instrumentation T4-L3. Laboratory tests showed a second, even more significant, increase in the amylase and lipase level and a moderate increase in the reactive C-protein. Therapy was maintained until complete normalization of amylase and lipase levels. CONCLUSIONS: Early recognition of symptoms plays a key role in preventing severe morbidity after scoliosis surgery. When symptoms suggest abdominal complication, pancreatic and liver enzymes are to be evaluated for posing prompt diagnosis. Gastroenterologic consultation and eventual imaging are further steps in differential diagnosis and treatment of this rare complication.

Lamins and bone disorders: current understanding and perspectives.

Lamin A/C is a major constituent of the nuclear lamina implicated in a number of genetic diseases, collectively known as laminopathies. The most severe forms of laminopathies feature, among other symptoms, congenital scoliosis, osteoporosis, osteolysis or delayed cranial ossification. Importantly, specific bone districts are typically affected in laminopathies. Spine is severely affected in LMNA-linked congenital muscular dystrophy. Mandible, terminal phalanges and clavicles undergo osteolytic processes in progeroid laminopathies and Restrictive Dermopathy, a lethal developmental laminopathy. This specificity suggests that lamin A/C regulates fine mechanisms of bone turnover, as supported by data showing that lamin A/C mutations activate non-canonical pathways of osteoclastogenesis, as the one dependent on TGF beta 2. Here, we review current knowledge on laminopathies affecting bone and LMNA involvement in bone turnover and highlight lamin-dependent mechanisms causing bone disorders. This knowledge can be exploited to identify new therapeutic approaches not only for laminopathies, but also for other rare diseases featuring bone abnormalities.

Osteoporotic thoracolumbar compression fractures: long-term retrospective comparison between vertebroplasty and conservative treatment.

PURPOSE: To compare long term clinical and radiographic outcomes in osteoporotic vertebral compression fractures of the thoracolumbar spine treated with conservative treatment and percutaneous vertebroplasty. METHODS: The retrospective study with inclusion criteria focused on osteoporotic fractures of the thoracolumbar junction (T10-L2). Clinical outcomes were evaluated by using the VAS, Oswestry and SF36 questionnaires. Radiographic outcomes were evaluated by comparing the following sagittal parameters: body angle, sagittal index of fractured vertebral body and adjacent vertebral segments kyphosis. Complications in terms of adjacent vertebral fractures and cement leakage are reported. RESULTS: Percutaneous vertebroplasty provided better vertebral body height restoration, but was associated with a higher incidence of adjacent fractures (20%) than conservative treatment (3.5%). This fact may explain why patients treated with percutaneous vertebroplasty had worse overall kyphotic alignment at final follow-up. Cement leakage was frequent, but always asymptomatic and generally no serious complications occurred. CONCLUSIONS: Percutaneous vertebroplasty represents a safe treatment for osteoporotic vertebral compression fractures, although it may be associated with a higher incidence of adjacent fractures and therefore worse thoracolumbar kyphosis and long-term follow-up than conservative treatment. These slides can be retrieved under Electronic Supplementary Material.

Treatment of recent onset low back pain with periradicular injections of meloxicam: a randomized, double blind, placebo controlled cross-over study.

BACKGROUND: Low back pain (LBP) is a common and costly illness. This randomized, double-blind, placebo-controlled, cross-over study tested the hypothesis that periradicular injections of meloxicam would reduce LBP and improve physical activity compared to a saline injection at 3 months follow-up. METHODS: After IRB approval, 80 consenting patients suffering LBP of <6 months duration were randomly assigned to the control (C-group, N.=40, receiving 10 mL of saline) or the meloxicam (M-group, N.=40, receiving 10 mg in 10 mL saline). If the pain Numeric Rating Score (NRS) at 24 hours remained >50% of the pretreatment score, the patient was crossed-over to the other group. A successful treatment was NRS<3 at 3 months follow-up. Secondary outcome measures which were assessed included work-absence, physical-assistance, physical-activities limitations and pain-related insomnia. RESULTS: The baseline NRS was 9.3 (95% CI: 8.9-9.7) in the C-group and 9.2 (95% CI: 8.8-9.6) in the M-group. At the 24 hours follow-up after the initial treatment, the mean NRS was 6.3 (95% CI: 5.4-7.2) in the C-group vs. 3.5 (95% CI: 2.6-4.4) in the M-group (P<0.05). The number of cross-over cases was significantly higher in the C-group (N.=31, 77.5% vs. N.=5, 12.5%, P<0.001). At the 3 months follow-up, 66 patients (35+31) were allocated in the M-group and 54 (82%) reported NRS Score <3, while only 14 (9+5) patients remained in the C-group and eight patients had NRS<3. CONCLUSIONS: Periradicular injection of meloxicam is an effective analgesic treatment for acute/subacute LBP. This novel use of meloxicam also leads to an improvement in the level of physical activity at the 3-month follow-up.

Segmental vs non-segmental thoracic pedicle screws constructs in adolescent idiopathic scoliosis: is there any implant alloy effect?

PURPOSE: The aim of this study is to understand how many anchor sites are necessary to obtain maximum posterior correction of idiopathic scoliotic curve and if the alloy of instrumentation, stainless steel or titanium, may have a role in the percent of scoliosis correction. METHODS: We reviewed 143 consecutive patients, affected by AIS (Lenke 1-2), who underwent a posterior spinal fusion with pedicle screw-only instrumentation between 2002 and 2005. According to the implant density and alloy used we divided the cohort in four groups. RESULTS: All 143 patients were reviewed at an average follow-up of 7, 2 years, the overall final main thoracic curve correction averaged 61.4%, whereas the implant density within the major curve averaged 71%. A significant correlation was observed between final% MT correction and preoperative MT flexibility and implant density. CONCLUSIONS: When stainless steel instrumentation is used non-segmental pedicle screw constructs seem to be equally effective as segmental instrumentations in obtaining satisfactory results in patients with main thoracic AIS. When the implant alloy used is titanium one, an implant density of ≥60% should be guaranteed to achieve similar results.

Implant Complications After Magnetically Controlled Growing Rods for Early Onset Scoliosis: A Multicenter Retrospective Review.

BACKGROUND: Traditional growing rods have a reported wound and implant complication rate as high as 58%. It is unclear whether the use of magnetically controlled growing rods (MCGR) will affect this rate. This study was performed to characterize surgical complications following MCGR in early onset scoliosis. METHODS: A multicenter retrospective review of MCGR cases was performed. Inclusion criteria were: (1) diagnosis of early onset scoliosis of any etiology; (2) 10 years and younger at time of index surgery; (3) preoperative major curve size >30 degrees; (4) preoperative thoracic spine height <22 cm. Complications were categorized as wound related and instrumentation related. Complications were also classified as early (<6 mo from index surgery) versus late (>6 mo). Distraction technique and interval of distraction was surgeon preference without standardization across sites. RESULTS: Fifty-four MCGR patients met inclusion criteria. There were 30 primary and 24 conversion procedures. Mean age at initial surgery was 7.3 years (range, 2.4 to 11 y), and mean duration of follow-up 19.4 months. Twenty-one (38.8%) of 54 patients had at least 1 complication. Fifteen (27.8%) had at least 1 revision surgery. Six (11.1%) had broken rods (2 to 4.5 and 4 to 5.5 mm rods); two 5.5 mm rods failed early (4 mo) and 4 late (mean=14.5 mo). Six (11.1%) patients experienced 1 episode of lack or loss of lengthening, of which 4 patients subsequently lengthened. Seven patients (13.0%) had either proximal or distal fixation-related complication at average of 8.4 months. Two patients (3.7%) had infections requiring incision and drainage; 1 early (2 wk) with wound drainage and 1 late (8 mo). The late case required removal of one of the dual rods. CONCLUSIONS: This study shows that compared with traditional growing rods, MCGR has a lower infection rate (3.7% vs. 11.1%). MCGR does not appear to prevent common implant-related complications such as rod or foundation failure. The long-term implication remains to be determined. LEVEL OF EVIDENCE: Level IV.

Goal-Directed Fluid Therapy Based on Stroke Volume Variation in Patients Undergoing Major Spine Surgery in the Prone Position: A Cohort Study.

STUDY DESIGN: A retrospective observational study. OBJECTIVE: The aim of this study was to test whether a goal-directed fluid therapy (GDFT) protocol, based on stroke volume variation (SVV), applied in major spine surgery performed in the prone position, would be effective in reducing peri-operative red blood cells transfusions. SUMMARY OF BACKGROUND DATA: Recent literature shows that optimizing perioperative fluid therapy is associated with lower complication rates and faster recovery. METHODS: Data from 23 patients who underwent posterior spine arthrodesis surgery and whose intraoperative fluid administration were managed with the GDFT protocol were retrospectively collected and compared with data from 23 matched controls who underwent the same surgical procedure in the same timeframe, and who received a liberal intraoperative fluid therapy. RESULTS: Patients in the GDFT group received less units of transfused red blood cells (primary endpoint) in the intra (0 vs. 2.0, P = 0.0 4) and postoperative period (2.0 vs. 4.0, P = 0.003). They also received a lower amount of intraoperative crystalloids, had fewer blood losses, and lower intraoperative peak lactate. In the postoperative period, patients in the GDFT group had fewer pulmonary complications and blood losses from surgical drains, needed less blood product transfusions, had a shorter intensive care unit stay, and a faster return of bowel function. We found no difference in the total length of stay among the two groups. CONCLUSION: Our study shows that application of a GDFT based on SVV in major spine surgery is feasible and can lead to reduced blood losses and transfusions, better postoperative respiratory performance, shorter ICU stay, and faster return of bowel function. LEVEL OF EVIDENCE: 3.

Does hybrid fixation prevent junctional disease after posterior fusion for degenerative lumbar disorders? A minimum 5-year follow-up study.

PURPOSE: Medium- to long-term retrospective evaluation of clinical and radiographic outcome in the treatment of degenerative lumbar diseases with hybrid posterior fixation. METHODS: Thirty patients were included with the mean age of 47.8 years (range 35 to 60 years). All patients underwent posterior lumbar instrumentation using hybrid fixation for lumbar stenosis with instability (13 cases), degenerative spondylolisthesis Meyerding grade I (6 cases), degenerative disc disease of one or more adjacent levels in six cases and mild lumbar degenerative scoliosis in five patients. Clinical outcomes were evaluated using Oswestry disability index (ODI), Roland and Morris disability questionnaire (RMDQ), and the visual analog scale (VAS) pain scores. All patients were assessed by preoperative, postoperative and follow-up standing plain radiographs and lateral X-rays with flexion and extension. Adjacent disc degeneration was also evaluated by magnetic resonance imaging (MRI) at follow-up. RESULTS: At a mean follow-up of 6.1 years, we observed on X-rays and/or MRI 3 cases of adjacent segment disease (10.0 %): two of them (6.6 %) presented symptoms and recurred a new surgery. The last patient (3.3 %) developed asymptomatic retrolisthesis of L3 not requiring revision surgery. The mean preoperative ODI score was 67.6, RMDQ score was 15.1, VAS back pain score was 9.5, and VAS leg pain score was 8.6. Postoperatively, these values improved to 28.1, 5.4, 3.1, and 2.9, respectively, and remained substantially unchanged at the final follow-up: (27.7, 5.2, 2.9, and 2.7, respectively). CONCLUSIONS: After 5-year follow-up, hybrid posterior lumbar fixation presented satisfying clinical outcomes in the treatment of degenerative disease.

Does surgery for Scheuermann kyphosis influence sagittal spinopelvic parameters?

PURPOSE: To analyze changes in sagittal spinopelvic parameters (SSPs) after surgical treatment of Scheuermann's Kyphosis (SK). METHODS: We analyzed 20 patients affected by SK and subjected to posterior correction of the kyphosis by facetectomy, Ponte osteotomy, fusion and multilevel instrumentation with pedicle screw system. Four spinal and three pelvic parameters were measured: sagittal vertical axis (SVA), thoracic kyphosis (TK), thoracolumbar kyphosis, lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS) and pelvic tilt (PT). Analysis of changes in postprocedural SSPs compared to preoperative values was performed. RESULTS: TK passed from 78.6° preoperatively to 45.8° (p = 0.003). LL passed from 74.5° preoperatively to 53.5° (p = 0.01). No significant changes occurred in SVA, SS, PT and PI compared to preoperative values. CONCLUSION: We confirm the positive effect of surgery by Ponte osteotomy and posterior spinal fusion on TK and LL in patients with SK. In our experience, pelvic parameters did not change after surgery.

Long-term systemic metal distribution in patients with stainless steel spinal instrumentation: a case-control study.

STUDY DESIGN: Case-control study. OBJECTIVE: To verify whether metal ions in the serum of patients bearing spinal stainless steel instrumentation were elevated over the long-term period after implantation of stainless steel prostheses and to determine whether these levels could predict potential unfavorable outcomes. SUMMARY OF BACKGROUND DATA: Instrumented spinal arthrodesis, the standard procedure to correct scoliosis, routinely remains in situ for the lifetime of the patient. Elevated metal ion levels have been reported at short-term follow-up, but the long-term status, possibly related to systemic toxic effects, is unknown. METHODS: Twenty-two patients treated for scoliosis with posterior spinal arthrodesis using stainless steel instrumentation were included. Minimum follow-up was 10 years. Oswestry Disability Index and visual analog scale were recorded. Chromium (Cr) and nickel (Ni) levels were measured (ng/mL) and compared with levels in a control group including 30 healthy subjects. A receiver-operating characteristic curve was calculated on the basis of the clinical assessment (pain and disability) and the x-ray picture; the cutoff values for the parameters were settled, and the ion-testing potential was considered as a surrogate marker for failure. RESULTS: The level of Cr was significantly increased in patients, compared with controls (P=0.018). A remarkable Cr release without any clinical-radiologic sign was recorded in some female patients. A high specificity (93%), positive likelihood ratio (7.00), and overall accuracy (77%) were calculated for Cr; these indicate a high risk of failure when the levels exceeded the cutoff value, which was 0.6 ng/mL. No significant difference between the groups was found for Ni (P=0.7). CONCLUSIONS: Cr testing is suggested as a reliable marker for the malfunctioning assessment and as a support for standard procedures, especially with doubtful diagnosis. Furthermore, high levels of Cr ions were observed in female patients. This finding deserves attention especially when counseling young fertile women.

Transforaminal Lumbar Interbody Fusion in Degenerative Disk Disease and Spondylolisthesis Grade I: Minimally Invasive Versus Open Surgery.

BACKGROUND: Interbody fusion represents an efficient surgical treatment in degenerative lumbar disease, achieving satisfying outcome in >90% of cases. Various studies have affirmed the advantages of percutaneous and minimally invasive techniques with regard to minimized damage on soft tissues during surgical procedure, but their efficacy in comparison with the classic open surgical procedures has not yet been demonstrated. MATERIALS AND METHODS: This is a retrospective study. We compared 30 consecutive patients affected by disk degenerative disease or grade I degenerative spondylolisthesis that were treated with minimally invasive transforaminal lumbar interbody fusion (mini-TLIF) to a group of 34 consecutive patients presenting similar pathologic findings and demographic characteristics that underwent interbody fusion by traditional open approach (open-TLIF). All patients were treated between 2006 and 2010. Patients' mean age was 46 years (min 28-max 56) and 51 years (min 32-max 58), respectively. Mean follow-up was 23 months (min 12-max 38) and 25 months (min 12-max 40), respectively. Clinical evaluation was performed by using Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) questionnaires. Radiographic evaluation was performed on standing and dynamic x-rays before operation and at final follow-up. RESULTS: There was a statistically significant improvement in clinical scores (VAS and ODI) in both groups. Early postoperative VAS score was significantly lower in the mini-TLIF group. Mean hospital stay and mean blood loss were significantly higher in the open-TLIF group than in the mini-TLIF group (7.4 vs. 4.1 d and 620 vs. 230 mL, respectively). Surgical time length of the procedure was higher in the mini-TLIF group. There were no major neurological complications in any of the patients. At final follow-up, radiographic evaluation showed good implant stability in both groups. CONCLUSIONS: Mini-TLIF is a safe and efficient procedure and, when correctly and carefully performed, can reach good results, similar to those obtained with traditional open surgical techniques, even though it may require a longer surgical time at least during the first stages of the learning curve. Reduced surgical invasiveness, short hospital stay, and limited blood loss represent the major advantages of minimally invasive technique.