The effect of subcutaneous fat and skin-to-lamina distance on complications and functional outcomes of minimally invasive lumbar decompression.

PURPOSE: Minimally invasive lumbar decompression (MIS) in obese pzatients is technically challenging due to the use of longer tube retractors. The purpose of this study was to evaluate the impact of the thickness of the soft tissue and subcutaneous fat on complications, revisions, and patient-reported functional outcomes after MIS. METHODS: This is a retrospective analysis of 148 consecutive patients who underwent minimally invasive lumbar decompression at our institute between 2013 and 2017 and had at least one year of follow-up. Analysis was performed five times, each time the study group was defined by another measure of adiposity: BMI > 30, skin to lamina distance at the site of surgery and at L4 > 6 cm, and subcutaneous fat thickness at the site of surgery and at L4 > 3 cm. Outcomes included intraoperative complications (durotomy or neurological deficit), possibly inadequate decompression (residual disc, reoperation), length of stay, return to the emergency room or readmission, postoperative medical complications, and functional outcomes: visual analog scores for back and leg pain, and Oswestry Disability Index (ODI). RESULTS: Patients with a thicker layer soft tissue had a significantly higher burden of comorbidities than controls, including higher prevalence of cardiovascular disease (p = 0.002), diabetes (p < 0.001), hypertension (p < 0.001) and higher ASA scores (p = 0.002). Nevertheless, there was no significant difference between the patient groups in surgical and medical complications, functional outcomes, and other assessed outcomes. CONCLUSION: Our results indicate that minimally invasive lumbar decompression is safe and effective for patients with a thick layer of soft tissue and subcutaneous fat.

Does Tobacco Smoking Affect the Postoperative Outcome of MIS Lumbar Decompression Surgery?

BACKGROUND: Tobacco smoking is a major cause of morbidity and mortality worldwide. Several authors reported a significant negative impact of smoking on the outcome of spinal surgeries. However, comparative studies on the effect of smoking on the outcome of minimally invasive (MIS) spinal decompression are rare with conflicting results. In this study, we aimed to evaluate clinical outcomes and postoperative complications following MIS decompression in current and former smoking patients compared to those of non-smoking patients. METHODS: We used our prospectively collected database to retrospectively analyse the records of 188 consecutive patients treated with MIS lumbar decompression at our institution between November 2013 and July 2017. Patients were divided into groups of smokers (S), previous smokers (PS) and non-smokers (N). The S group and the PS group comprised 31 and 40 patients, respectively. The N group included 117 patients. The outcome measures included perioperative complications, revision surgery and length of stay. Patient-reported outcome measures included a visual analogue scale (VAS) for back pain and leg pain, as well as the Oswestry disability index (ODI) for evaluating functional outcomes. RESULTS: Demographic variables, comorbidity and other preoperative variables were comparable between the three groups. A comparison of perioperative complications and revision surgery rates showed no significant difference between the groups. All groups showed significant improvement in their ODI and VAS scores at 12 and 24 months following surgery. As shown by a multivariate analysis, current smokers had lower chances of improvement, exceeding the minimal clinical important difference (MCID) in ODI and VAS for leg pain at 12 months but not 24 months postoperatively. CONCLUSIONS: Our findings show that except for a possible delay in improvement in leg pain and disability, tobacco smoking has no substantial adverse impact on complications and revision rates following MIS spinal decompressions.

Low Back Pain Patients' Perceptions Regarding Their Own Radiology Reports: Pre-Intervention Survey.

Purpose: While advanced medical technology and unlimited access to medical information might benefit and empower patients, these same advantages may pose some risks, especially in the cases where patients have direct access to advanced imaging studies. The aim of this work was to evaluate three domains related to patients with lower back pain: the patients' perceptions, misconceptions and the experience of anxiety-related symptoms following direct access to their thoraco-lumbar spine radiology report. An additional aim was the assessment of possible associations with catastrophization. Patients and Methods: Patients who were referred to the spine clinic, following the completion of a CT or MRI of their thoraco-lumbar spine were surveyed. Patient perceptions of the importance of having direct access to their imaging report and of the concern they attribute to the medical terms found in their report were evaluated using a set of questionnaires. The medical terms severity scores were then correlated to a reference clinical score created for the same medical terms by spine surgeons. Lastly, patients' anxiety-related symptoms and Pain Catastrophizing Scale (PCS) after reading their radiology report were evaluated. Results: Data from 162 participants (44.6% female), with mean age of 53.1 ± 15.6 years, were collected. Sixty-three percent of the patients stated that reading their report helped them gain better understanding of their medical condition and 84% agreed that having early access to the report helped improve communication with the physician. Patients' degree of concern associated with the medical terms in their imaging report ranged between 2.07 and 3.75, on a scale of 1-5. The patient's degree of concerns were significantly higher for six common medical terms and significantly lower in one, when compared to experts' opinions. A mean (± SD) of 2.86±2.79 anxiety-related symptoms was reported. The mean Pain Catastrophizing Scale (PSC) score was 29.18 ±11.86, ranging from 2 to 52. Both the degree of concerns and the number of symptoms reported were significantly associated with the PCS. Conclusion: Direct access to radiology reports might provoke anxiety symptoms, especially in patients with a tendency for catastrophic thinking. Increasing awareness amongst spine clinicians and radiologist about possible risks associated with direct access to radiology reports could contribute to preventing patients' misconceptions and unnecessary anxiety-related symptoms.

Minimally Invasive Resection of Benign Osseous Tumors of the Spinal Column: 10 Years' Experience and Long-Term Outcomes of a Specialized Center.

Background and Objectives: Benign osseous tumors of the spinal column comprise about 10% of all spinal tumors and are rare cause for surgery. However, these tumors pose various management challenges and conventional surgery may be associated with significant morbidity. Previous reports on minimally invasive resection of these lesions are rare. We report a series of patients managed by total resection of benign osseous spine tumors using MIS techniques. Surgical decisions and technical considerations are discussed. Materials and Methods: A retrospective evaluation of prospectively collected data of patients who underwent minimally invasive surgery for removal of benign osseous vertebral tumors. Demographic, clinical and radiographic features, operative details and final pathological reports were summarized. Primary outcomes were completeness of tumor resection and pain relief assessed by VAS for back and leg pain. Secondary outcome measures were recurrence of tumor on repeat post-operative MRI and postoperative unstable deformity on standing scoliosis X-rays. Results: This series included 32 cases of primary osseous spine tumors resected by minimally invasive techniques. There were 17 males and 15 females aged 5-68 years (mean 23.3). The follow-up period was 8-90 months (mean 32 months) and the preoperative symptoms duration was 9-96 months. Axial spinal pain was the presenting symptom in all the patients. Five patients also complained about radicular pain and four patients had antalgic scoliosis. The tumor involved the thoracic spine in 12 cases, the lumbar segment in 11, the cervical in 5 and the sacral area in 4 cases. Complete tumor removal was performed in all patients. No procedure-related complications were encountered. Histopathology showed osteoid osteoma in 24 patients, osteoblastoma in 5 patients, and fibrous dysplasia, fibroadenoma and eosinophilic granuloma in one case each. All patients experienced significant pain relief after surgery, and had stopped pain medications by 12 months postoperatively. No patient suffered from tumor recurrence or spinal deformity. Conclusions: Minimally invasive surgery is feasible for total removal of selected benign vertebral tumors and may have some advantages over conventional surgical techniques.

Sarcopenia Is an Independent Risk Factor for Subsequent Osteoporotic Vertebral Fractures Following Percutaneous Cement Augmentation in Elderly Patients.

Introduction: Subsequent osteoporotic vertebral fractures (SOVF) are a serious complication of osteoporosis that can lead to spinal deformity, chronic pain and disability. Several risk factors have been previously identified for developing SOVF. However, there are conflicting reports regarding the association between sarcopenia and multiple vertebral compression fractures. As such, the goal of this study was to investigate whether sarcopenia is an independent risk factor of SOVF. Methods: This was a retrospective case-control study of elderly patients who underwent percutaneous vertebral augmentation (PVA) due to a new osteoporotic vertebral compression fracture (OVCF). Collected data included: age, sex, BMI, steroid treatment, fracture level and type, presence of kyphosis at the level of the fracture and bone mineral density (BMD). Identification of SVOFs was based on clinical notes and imaging corroborating the presence of a new fracture. Sarcopenia was measured using the normalized psoas muscle total cross-sectional area (nCSA) at the L4 level. Results: Eighty-nine patients that underwent PVA were followed for a minimum of 24 months. Average age was 80.2 ± 7.1 years; 58 were female (65.2%) and 31 male (34.8%). Psoas muscle nCSA was significantly associated with age (p = 0.031) but not with gender (p = 0.129), corticosteroid treatment (p = 0.349), local kyphosis (p = 0.715), or BMD (p = 0.724). Sarcopenia was significantly associated with SOVF (p = 0.039) after controlling for age and gender. Conclusions: Psoas muscle nCSA can be used as a standalone diagnostic tool of sarcopenia in patients undergoing PVA. In patients undergoing PVA for OVCF, sarcopenia is an independent risk factor for SOVF.

Minimally invasive discectomy versus open laminectomy and discectomy for the treatment of cauda equina syndrome: A preliminary study and case series.

Background: Cauda Equina syndrome (CES) is a potentially devastating condition and is treated usually with urgent open surgical decompression of the spinal canal. Currently, the role of minimally invasive discectomy (MID) as an alternative surgical technique for CES is unclear. Objective: The purpose of this study was to compare clinical outcomes following MID and open laminectomy and discectomy for the treatment of CES. Methods: The study cohort included patients that underwent surgery due to CES at our institute. Patients' outcomes included: surgical complications, length of hospitalization, postoperative lower extremity motor score (LEMS), Numerical Rating Scale (NRS) for leg and back pain, Oswestry disability index (ODI), and the EQ-5D health-related quality of life questionnaire. Results: Twelve patients underwent MID and 12 underwent open laminectomy and discectomy. Complications and revisions rates were comparable between the groups. Postoperative urine incontinence and saddle dysesthesia improved in 50% of patients in both groups. LEMS improved from 47.08 ± 5.4 to 49.27 ± 0.9 in the MID group and from 44.46 ± 5.9 to 49.0 ± 1.4 in the open group. Although, leg pain improved in both groups from 8.4 ± 2.4 to 3 ± 2.1 in the MID and from 8.44 ± 3.3 to 3.88 ± 3 in the open group, significant improvement in back pain was found only in the MID group. Final functional scores were similar between groups. Conclusions: Our preliminary results suggest that minimally invasive discectomy is an effective and safe procedure for the treatment of CES when compared to open laminectomy and discectomy. However, MID in these cases should only be considered by surgeons experienced in minimally invasive spine surgery. Further studies with bigger sample sizes and long-term follow-ups are needed.

Facet overhang: A novel parameter in the pathophysiology of multifidus muscle atrophy.

The relationship between degenerative zygapophysial joint (facet) arthropathy and multifidus muscle atrophy has not been rigorously evaluated. The purpose of this study was to determine if specific morphological features of degenerative facet arthropathy are correlated with multifidus muscle atrophy. We retrospectively reviewed medical records and imaging studies of patients with lumbar spinal stenosis. Facet overhang, bridging osteophyte formation, facet effusion, and facet angles were evaluated by univariable and multivariable regression to identify independent associations with deep and superficial parts of the multifidus total cross-sectional area (tCSA), functional cross-sectional area (fnCSA), and fatty infiltration (FI). Facet overhang was classified as severe in 50 females (53.2%) versus 56 males (36.9%) (p = 0.030). Severity of facet overhang and female sex were independently associated with smaller deep part of the multifidus tCSA and fnCSA as well as higher FI, reflecting greater atrophy of the deep region compared to total muscle mass. In comparison, severe facet overhang (p < 0.001; OR = 3.47, 95% CI = 2.13-5.66) and female sex (p < 0.001; OR = 4.19, 95% CI = 2.58-6.79) were independently associated only with higher superficial part of the multifidus FI, reflecting muscle steatosis without significant lean muscle atrophy. In patients with degenerative lumbar spinal stenosis, facet overhang is an independent risk factor for deep part of the multifidus atrophy. Bridging osteophyte formation, facet effusion, and facet angles were not independently associated with deep part of the multifidus atrophy.

Predictors of functional recovery following surgery for foot drop due to degenerative lumbar disease.

OBJECTIVE: Surgery for foot drop secondary to lumbar degenerative disease is not always associated with postoperative functional improvement. It is still unclear whether early decompression results in better functional recovery and how soon surgery should be performed. This study aimed to evaluate predicting factors that affect short- and long-term recovery outcomes and to explore the relationship between timing of lumbar decompression and recovery from foot drop in an attempt to identify a cutoff time from symptom onset until decompression for optimal functional improvement. METHODS: The authors collected demographic, clinical, and radiographic data on patients who underwent surgery for foot drop due to lumbar degenerative disease. Clinical data included tibialis anterior muscle (TAM) strength before and after surgery, duration of preoperative motor weakness, and duration of radicular pain until surgery. TAM strength was recorded at the immediate postoperative period and 1 month after surgery while long-term follow-up on functional outcomes were obtained at ≥ 2 years postsurgery by telephone interview. Data including degree and duration of preoperative motor weakness as well as the occurrence of pain and its duration were collected to analyze their impact on short- and long-term outcomes. RESULTS: The majority of patients (70%) showed functional improvement within 1 month postsurgery and 40% recovered to normal or near-normal strength. Univariate analysis revealed a trend toward lower improvement rates in patients with preoperative weakness of more than 3 weeks (33%) compared with patients who were operated on earlier (76.5%, p = 0.034). In a multivariate analysis, the only significant predictor for maximal strength recovery was TAM strength before surgery (OR 6.80, 95% CI 1.38-33.42, p = 0.018). Maximal recovery by 1 month after surgery was significantly associated with sustained long-term functional improvement (p = 0.006). CONCLUSIONS: Early surgery may improve the recovery rate in patients with foot drop caused by lumbar degenerative disease, yet the strongest predictor for the extent of recovery is the severity of preoperative TAM weakness. Maximal recovery in the short-term postoperative period is associated with sustained long-term functional improvement and independence.

Stable Low-Grade Degenerative Spondylolisthesis Does Not Compromise Clinical Outcome of Minimally Invasive Tubular Decompression in Patients with Spinal Stenosis.

Background and Objectives: In recent literature, the routine addition of arthrodesis to decompression for lumbar spinal stenosis (LSS) with concomitant stable low-grade degenerative spondylolisthesis remains controversial. The purpose of this study is to compare the clinical outcome, complication and re-operation rates following minimally invasive (MIS) tubular decompression without arthrodesis in patients suffering from LSS with or without concomitant stable low-grade degenerative spondylolisthesis. Materials and Methods: This study is a retrospective review of prospectively collected data. Ninety-six consecutive patients who underwent elective MIS lumbar decompression with a mean follow-up of 27.5 months were included in the study. The spondylolisthesis (S) group comprised 53 patients who suffered from LSS with stable degenerative spondylolisthesis, and the control (N) group included 43 patients suffering from LSS without spondylolisthesis. Outcome measures included complications and revision surgery rates. Pre- and post-operative visual analog scale (VAS) for both back and leg pain was analyzed, and the Oswestry Disability Index (ODI) was used to evaluate functional outcome. Results: The two groups were comparable in most demographic and preoperative variables. VAS for back and leg pain improved significantly following surgery in both groups. Both groups showed significant improvement in their ODI scores, at one and two years postoperatively. The average length of hospital stay was significantly higher in patients with spondylolisthesis (p-value< 0.01). There was no significant difference between the groups in terms of post-operative complications rates or re-operation rates. Conclusions: Our results indicate that MIS tubular decompression may be an effective and safe procedure for patients suffering from LSS, with or without degenerative stable spondylolisthesis.

Long-Term Pain Characteristics and Management Following Minimally Invasive Spinal Decompression and Open Laminectomy and Fusion for Spinal Stenosis.

Background and Objectives: To compare the long-term pain characteristics and its chronic management following minimally invasive spinal (MIS) decompression and open laminectomy with fusion for lumbar stenosis. Materials and Methods: The study cohort included patients with a minimum 5-year postoperative follow-up after undergoing either MIS decompression or laminectomy with fusion for spinal claudication. The primary outcome of interest was chronic back and leg pain intensity. Secondary outcome measures included pain frequency during the day, chronic use of non-opioid analgesics, narcotic medications, medical cannabinoids, and continuous interventional pain treatments. Results: A total of 95 patients with lumbar spinal stenosis underwent one- or two-level surgery for lumbar spinal stenosis between April 2009 and July 2013. Of these, 50 patients underwent MIS decompression and 45 patients underwent open laminectomy with instrumented fusion. In the fusion group, a higher percentage of patients experienced moderate-to-severe back pain with 48% compared to 21.8% of patients in the MIS decompression group (p < 0.01). In contrast, we found no significant difference in the reported leg pain in both groups. In the fusion group, 20% of the patients described their back and leg pain as persistent throughout the day compared to only 2.2% in the MIS decompression group (p < 0.05). A trend toward higher chronic dependence on analgesic medication and repetitive pain clinic treatments was found in the fusion group. Conclusions: MIS decompression for the treatment of degenerative spinal stenosis resulted in decreased long-term back pain and similar leg pain outcomes compared to open laminectomy and instrumented fusion surgery.

Resection of Benign Osseous Spine Tumors in Pediatric Patients by Minimally Invasive Techniques.

OBJECTIVE: Benign osseous tumors of the spine in children are a rare cause for surgery. The aim of this study is to describe our experience with resection of pediatric benign osseous spine tumors using a minimally invasive technique through a variety of surgical approaches. METHODS: A retrospective review of prospectively collected data of pediatric patients who underwent minimally invasive resection of a benign osseous vertebral tumor from May 2013 through November 2018 was performed. Primary outcome measures included the extent of resection and pain resolution. Secondary outcomes included postoperative spinal instability evaluated by standing scoliosis x-rays and tumor recurrence evaluated by periodic follow-up magnetic resonance imaging scans. RESULTS: Our study group comprised 8 children, 3 males and 5 females, with a mean age of 12.2 years. The average follow-up period was 4.3 years. Complete removal of tumors was achieved in all cases and was verified by follow-up magnetic resonance imaging scans. There were no procedure-related complications. The average duration of surgery was 70 minutes, and the blood loss was less than 20 cc in all cases. The average inpatient length of stay was 1.6 days. Histopathology revealed osteoid osteoma in 6 patients and osteoblastoma in 2 patients. Average improvement of the pain scores was from 8 to 0.8. At the time of this report, no tumor recurrence was evident in all 8 patients and none of the cases developed spinal deformity. CONCLUSION: Our limited experience suggests that the minimally invasive technique is a valuable option for the surgical management of selected benign osseous spinal tumors in children.

A Comparison of Different Minimally Invasive and Open Posterior Spinal Procedures Using Volumetric Measurements of the Surgical Exposures.

STUDY DESIGN: A Prospective observational study. SUMMARY OF THE BACKGROUND DATA: Minimally invasive (MI) spine surgery techniques strive to minimize the damage to paraspinal soft tissues. Previous studies used only the length of the surgical incision to quantify the invasiveness of certain MI procedures. However, this method does not take into account the volume of muscle tissue that is dissected and retracted from the spine to achieve sufficient exposure. To date, no simple method has been reported to measure the volume of the surgical exposure and to quantify the degree of surgery invasiveness. STUDY OBJECTIVES: To obtain and compare volumetric measures of various MI and open posterior-approached spinal surgical exposures. METHODS: The length, the depth, and the volume of the surgical exposure were obtained from 57 patients who underwent either open or MI posterior lumbar surgery. MI procedures included the following: tubular discectomy, laminotomy, and transforaminal interbody fusion. Open procedures included the following: discectomy, laminectomy, transforaminal interbody fusion, or posterior-lateral instrumented fusion. Four attending spine surgeons at our unit performed the surgeries. To reduce variability, only single-level procedures performed between L4 and S1 vertebrae were used. The volume of exposure was obtained by measuring the amount of saline needed to fill the surgical wound completely once the surgical retractors were deployed and opened. RESULTS: The average volumes in mililiters of exposure for a single-level MI procedure ranged from 9.8±2.8 to 75±11.7 mL and were significantly smaller than the average volumes of exposure for a single level open procedures that ranged from 44± 21 to 277±47.9 P<0.001. The average skin-incision lengths for single-level MI procedures ranged from 1.7±0.2 to 7.7±1.6 cm and were significantly smaller than the average skin-incision lengths for open procedures [5.2±1.4 (Table 3) to 11.3±2 cm, P<0.001]. The measured surgical depths were similar in MI and open groups (P=0.138). MI decompression and posterior fusion procedures yielded 92% and 73% reductions in the volumes of exposure, respectively. However, absolute differences in exposure volumes were larger for fusion (202 mL) compared with decompression alone (110.7 mL). CONCLUSIONS: Direct volumetric measurement of the surgical exposure is obtained easily by measuring the amount of saline needed to fill the exposed cavity. Using this method, the needed surgical exposure of different spinal procedures can be quantified and compared. This volumetric measurement combined with the measure of retraction force, the duration of retraction, and the impact on soft tissue vascularity can help build a model that assesses the relative invasiveness of different spinal procedures.

Electrophysiological monitoring during preoperative angiography to guide decisions regarding permanent occlusion of major radicular arteries in patients undergoing total en bloc spondylectomy.

OBJECTIVE Preoperative embolization is performed before spine tumor surgery when significant intraoperative hemorrhage is anticipated. Occlusion of radicular and segmental arteries may result in spinal ischemia. The goal of this study was to check whether neurophysiological monitoring during preoperative angiography in patients scheduled for total en bloc spondylectomy (TES) of spine tumors improves the safety of vessel occlusion. METHODS This was a case series study of patients who underwent tumor embolization under somatosensory evoked potential (SSEP) and motor evoked potential (MEP) monitoring in preparation for TES in treating spine tumors. The angiography findings, the embolized vessels, and the results are presented. RESULTS Five patients whose ages ranged from 33 to 75 years and who had thoracic spine tumors are reported. Four patients suffered from primary tumor and 1 patient had a metastatic tumor. Radicular arteries at the tumor level, 1 level above, and 1 level below were permanently occluded when SSEPs and MEPs were preserved during temporary occlusion. No complications were encountered during or after the angiography procedure and embolization. CONCLUSIONS Temporary occlusion with electrophysiological monitoring during preoperative angiography may improve the safety of permanent radicular artery occlusion, including the artery of Adamkiewicz in patients undergoing TES for the treatment of spine tumors.

Minimally Invasive Spinal Decompression in Patients Older Than 75 Years of Age: Perioperative Risks, Complications, and Clinical Outcomes Compared with Patients Younger Than 45 Years of Age.

OBJECTIVE: Minimally invasive spinal decompression for the treatment of spinal stenosis or disk herniation is often indicated if conservative management fails. However, the influence of old age on the risk of postoperative complications and clinical outcome is not well understood. We therefore sought to compare complication rates and outcomes after minimally invasive surgery decompression and discectomy in elderly patients with a cohort of younger patients undergoing similar procedures. METHODS: We evaluated medical records of 61 patients older than 75 years and 69 patients younger than 45 years that underwent minimally invasive lumbar decompression between April 2009 and July 2013 at our institute. Medical history, American Society of Anesthesiologists score, perioperative mortality, complications, and revision surgery rates were analyzed. Patient outcomes included visual analog scale and EuroQol-5 Dimension scores. RESULTS: The average age was 78.66 ± 4.42 years in the elderly group and 33.59 ± 6.7 years in the younger group. No major postoperative complications were recorded in either group, and all recruited patients were still alive at the time of the last follow-up. No statistically significant difference existed in the surgical revision rate between the groups. Both groups showed significant improvement in their outcome scores after surgery. CONCLUSIONS: Our results indicate that minimally invasive decompressive surgery is a safe and effective treatment for elderly patients and does not pose an increased risk of complications. Future prospective studies are necessary to validate the specific advantages of the minimally invasive techniques in the elderly population.

The results of two-stage revision TKA using Ceftazidime-Vancomycin-impregnated cement articulating spacers in Tsukayama Type II periprosthetic joint infections.

PURPOSE: This study examined the success and factors associated with failure, of using cement spacers impregnated with high-dose Ceftazidime and Vancomycin when performing two-stage revision for infected total knee arthroplasty (TKA). METHODS: A retrospective analysis was performed using a prospectively collected database of 82 patients (median age 68 years, range 39-87) with a confirmed deep TKA infection treated with a two-stage revision. All cement spacers were impregnated with high-dose Ceftazidime and Vancomycin. The rate of success was recorded-an association between failure of treatment, and patient factors, previous surgical treatment, and microbial characteristics was sought. RESULTS: The mean time to infection from index arthroplasty was 45 months (range 3-240). The initial two-stage revision was successful in 70/82 patients (85.4 %), who remained free of infection at average follow-up of 36.2 months (range 24-85). A second two-stage revision for infection was required in 12/82 patients (14.6 %), which was successful in 4/12 (33 %). A third two-stage revision was performed in three patients, all of whom had a polymicrobial infection of which only one patient had successful eradication of infection. Recurrent infection was correlated with irrigation and debridement with implant retention prior to initial two-stage revision (p < 0.01), polymicrobial infections (p = 0.035), and infections presenting <6 months after index surgery (p = 0.031). No correlation was seen with age, BMI, type of organism, diabetes mellitus, or Charlson Comorbidity Index. CONCLUSION: The findings of this study suggest that the combination of Ceftazidime and Vancomycin in cement spacers is as efficacious as other published single or combined antibiotic mixtures, which is clinically relevant to clinicians treating this difficult problem in the setting of patients with compromised renal function.

Resection of benign vertebral tumors by minimally invasive techniques.

BACKGROUND CONTEXT: Benign tumors of the vertebrae are generally an uncommon cause for surgery. Complete removal of these tumors requires in most cases extensive surgical technique that consists of generous surgical exposure followed by laminectomy, facetectomy, and sometimes even an instrumented fusion. PURPOSE: The aim was to describe our experience in performing resection of benign vertebral tumors, using a minimally invasive surgical (MIS) approach. STUDY DESIGN: This was a retrospective review of case records. PATIENT SAMPLE: Patients who underwent MIS, resection of benign vertebral tumors. OUTCOME MEASURES: Complete neurologic examination and pain evaluation, as measured by the visual analog scale (VAS). Secondary outcomes included postoperative spinal instability assessment and surgical margins examinations. METHODS: Patients were evaluated preoperatively and postoperatively at 1, 3, and 6 months intervals clinically and radiographically using plain radiographs and postoperative computed tomography (CT) scans. Final pathologic report, operative time, blood loss, complications, and hospital length of stay were also recorded. RESULTS: Between 2009 and 2013, 14 patients underwent MIS, resection of benign vertebral tumors at our institution. Mean follow-up time was 4 years. There were eight men and six women with a mean age of 27 years (range 16-68 years). For tumors located in the posterior elements, a direct posterior approach was used. Tumors located at the pedicle of the vertebra were excised using a transpedicular approach, and tumors protruding into the foramen were excised using the transforaminal approach. The transcanal approach was used when decompression of the thecal sac or nerve root was required, and the retroperitoneal transpsoas approach was used for tumors located in the vertebral body. Complete removal of these tumors was achieved in all cases, and was verified by a follow-up CT scan. Pathology revealed osteoid osteoma in five patients, osteoblastoma in three patients. Eosinophilic granuloma, fibrous dysplasia, and fibroid adenoma were found in one case each. Average VAS pain score improved from 7.7 (7-9) to 2.8 (0-7) after surgery. CONCLUSIONS: Minimally invasive techniques are a valuable choice for the treatment of benign osseous tumors of the spine. A larger, long-term study is in progress. In the meantime, we suggest surgeons experienced with both open and MIS surgery should consider these techniques.

Safety and the anatomy of the retroperitoneal lateral corridor with respect to the minimally invasive lateral lumbar intervertebral fusion approach.

Safe and reproducible outcomes of the lateral lumbar intervertebral fusion (LLIF) procedure rely on meticulous care and understanding of the anatomy of the lateral corridor. This review aims to describe the different important anatomic considerations when performing LLIF and offer technical notes that may help increase the safety of this procedure. The LLIF procedure is divided into 5 stages: patient positioning, abdominal wall dissection, retroperitoneal space dissection, deployment of the surgical retractors, and diskectomy. Each stage is preformed in a distinct anatomic compartment that may cause different typical complications.

Delayed diagnosis of cervical spondylotic myelopathy by primary care physicians.

OBJECT: A retrospective study analyzing medical files of patients who had undergone surgical management for cervical spondylotic myelopathy (CSM) at a single tertiary hospital was performed to determine the time needed by community care physicians to reach a diagnosis of CSM in patients presenting with typical myelopathic signs and symptoms, and to establish the reasons for the delayed diagnosis when present. Previous studies have documented that early diagnosis and surgical treatment of CSM may improve patients' neurological as well as general outcome. However, patients complaining of symptoms compatible with CSM may undergo lengthy medical investigations and treatments by community-based physicians before a correct diagnosis is made. The authors have found no published data on the process and time frame involved in attaining a diagnosis of CSM in the community setting. METHODS: The medical records of 42 patients were retrospectively reviewed for demographic data, symptoms, time to diagnosis, physician specialty, number of visits involved in the diagnostic process, and neurological status prior to surgery. RESULTS: The mean time delay from initiation of symptoms to diagnosis of CSM was 2.2 ± 2.3 years. The majority of symptomatic patients (90.4%) initially presented to a family practitioner (69%) or an orthopedic surgeon (21.4%), with fewer patients (9.6%) referring to other disciplines (for example, the emergency department) for initial care. In contrast, the diagnosis of CSM was most often made by neurosurgeons (38.1%) and neurologists (28.6%), and less frequently by orthopedic surgeons (19%) or family physicians (4.8%). CONCLUSIONS: The diagnosis of CSM in the community is frequently delayed, leading to late referral for surgery. A higher index of suspicion for this debilitating entity is required from family practitioners and community-based orthopedic surgeons to prevent neurological sequelae.

Evaluation of hip flexion strength following lateral lumbar interbody fusion.

BACKGROUND CONTEXT: Lateral interbody fusion (LIF) is a minimally invasive procedure that is designed to achieve a solid interbody fusion while minimizing the damage to the surrounding soft tissue. Although short-term results have been promising, few data have been published to date regarding its risks and complication rate. PURPOSE: The aim was to evaluate the extent of injury to the psoas muscle after the LIF procedure by measuring hip flexion strength. STUDY DESIGN: A prospective case series was used in the study. METHOD: Hip flexion strength was measured using a handheld digital dynamometer while the patient was seated on a chair; the examiner held the device against the patient's attempt to flex the hip. Both sides were measured to compare the operated and nonoperated psoas muscles. Each side was measured three times and the average amount (in pounds) was recorded. Measurements were done before and after surgery on Day 2-3, at 2 weeks, 6 weeks, and at 3 and 6 months. RESULTS: Thirty-three patients were recruited for this study. Mean preoperative hip flexion strength values were 20.7±3.47 lb and 21.3±4.31 lb for operated and nonoperated legs, respectively, with no significant difference (p=.85). With a mean of 11.2±2.24 lb postoperative measurements on Day 2, the operated side showed statistically significant reduction of strength (p=.0001). The nonoperated side was also weaker postoperatively, but not significantly (mean=19.12±1.74 lb; p=.097). From the first follow-up visit at 2 weeks, the values on the operated leg had returned to baseline values (20.6, p=.97) and were not significantly different from preoperative values on either side. DISCUSSION: Hip flexion was weakened immediately after the LIF procedure, which may be attributed to psoas muscle injury during the procedure. However, this damage was temporary, with almost complete return to baseline values by 2 weeks.

Minimally invasive transforaminal, thoracic microscopic discectomy: technical report and preliminary results and complications.

BACKGROUND CONTEXT: Surgical decompression of thoracic disc herniations is technically challenging because retraction of the thecal sac in this area must be avoided. Standard open thoracic discectomy procedures require fairly extensive soft tissue dissection and vertebral resection to provide safe decompression of the spinal cord. PURPOSE: To describe our experience using a minimally invasive, transforaminal thoracic discectomy (MITTD) technique for the treatment of thoracic disc herniation. STUDY DESIGN: Technical report and preliminary results and complications. METHODS: Twelve patients undergoing MITTD were evaluated preoperatively and postoperatively at 1-, 3-, and 6-month intervals with neurologic examination, and were graded using the American Spinal Injury Association (ASIA) impairment scale and a pain visual analog scale (VAS). Thoracic instability and bony fusion were assessed clinically and radiographically with plain radiographs and computed tomography (CT) scans. Surgical time, blood loss, complications, and hospital length of stay were recorded. RESULTS: Twelve patients (seven men and five women) underwent MITTD. The median surgical time was 128 (80 to 185) minutes, the median estimated blood loss was 100 (30 to 250) mL, and the median hospital stay was 2 (1 to 4) nights. All discs were successfully removed, and a CT or magnetic resonance imaging confirmed adequate cord decompression in all cases. All patients reported easing of neurologic symptoms and improved walking ability. The median VAS scores improved from 4.5 to 2 for back pain. The ASIA score improved from D to E in the two patients who suffered from motor weakness. Preoperative sensory deficit was reduced in three of the five patients. Patients who suffered from sexual and urinary disturbances did not report improvement. Serious systemic or local complications and neurologic deterioration were not reported. CONCLUSIONS: The transforaminal approach enabled sufficient access to the midline of the spinal canal without extensive resection of the facet joint or the adjacent pedicle. Because most of the osseous and ligamentous structures were preserved, additional instrumentation was not required to prevent postoperative instability. Our early results suggested that minimally invasive thoracic discectomy by transforaminal microscopic technique is a valuable choice in the management of thoracic disc herniation.