Do TLIF and PLIF Techniques Differ in Perioperative Complications? - Comparison of Complications Rates of Two High Volume Centers.

STUDY DESIGN: Retrospective bicentric Cohort Study. OBJECTIVE: Posterior (PLIF) and transforaminal lumbar interbody fusion (TLIF) have been clinically proven for the surgical treatment of degenerative spinal disorders. Despite many retrospective studies, the superiority of either technique has not been proven to date. In the literature, the complication rate of the conventional PLIF technique is reported to be significantly higher, but with inconsistent complication recording. In this retrospective bicentric study, a less invasive PLIF technique was compared with the conventional TLIF technique and complications were recorded using the validated SAVES V2 classification system. METHODS: 1142 patients underwent PLIF (702) or TLIF (n = 440) up to 3 levels in two specialized centers. Epidemiological data, intra- and postoperative complications during hospitalization and after discharge were analyzed according to SAVES V2. RESULTS: The overall complication rate was 13.74%. TLIF-patients had slightly significant more complications than PLIF-patients (TLIF = 16.6%/PLIF = 11.9%, P = .0338). Accordingly, complications during revision surgeries were more frequent in the first cohort (TLIF = 20.9%/PLIF = 12.6%; P = .03252). In primary interventions, the surgical technique did not correlate with the complication rate (TLIF = 12.4%/PLIF = 11.7%). There were no significant differences regarding severity of complications. CONCLUSIONS: An important component of this work is the complication recording according to a uniform classification system (SAVES V2). In contrast to previous literature, we could demonstrate that there is not a significant difference between the two surgical techniques.

AO Spine Guideline for the Use of Osteobiologics (AOGO) in Anterior Cervical Discectomy and Fusion for Spinal Degenerative Cases.

STUDY DESIGN: Guideline. OBJECTIVES: To develop an international guideline (AOGO) about the use of osteobiologics in anterior cervical discectomy and fusion (ACDF) for treating degenerative spine conditions. METHODS: The guideline development process was guided by AO Spine Knowledge Forum Degenerative (KF Degen) and followed the Guideline International Network McMaster Guideline Development Checklist. The process involved 73 participants with expertise in degenerative spine diseases and surgery from 22 countries. Fifteen systematic reviews were conducted addressing respective key topics and evidence was collected. The methodologist compiled the evidence into GRADE Evidence-to-Decision frameworks. Guideline panel members judged the outcomes and other criteria and made the final recommendations through consensus. RESULTS: Five conditional recommendations were created. A conditional recommendation is about the use of allograft, autograft or a cage with an osteobiologic in primary ACDF surgery. Other conditional recommendations are about the use of osteobiologic for single- or multi-level ACDF, and for hybrid construct surgery. It is suggested that surgeons use other osteobiologics rather than human bone morphogenetic protein-2 (BMP-2) in common clinical situations. Surgeons are recommended to choose 1 graft over another or 1 osteobiologic over another primarily based on clinical situation, and the costs and availability of the materials. CONCLUSION: This AOGO guideline is the first to provide recommendations for the use of osteobiologics in ACDF. Despite the comprehensive searches for evidence, there were few studies completed with small sample sizes and primarily as case series with inherent risks of bias. Therefore, high-quality clinical evidence is demanded to improve the guideline.

The prevalence of redundant nerve roots in standing positional MRI decreases by half in supine and almost to zero in flexed seated position: a retrospective cross-sectional cohort study.

PURPOSE: This retrospective cross-sectional cohort study investigated the influence of posture on lordosis (LL), length of the spinal canal (LSC), anteroposterior diameter (APD L1-L5), dural cross-sectional area (DCSA) of the lumbar spinal canal, and the prevalence of redundant nerve roots (RNR) using positional magnetic resonance imaging (MRI) (0.6 T). METHODS: Sixty-eight patients with single-level degenerative central lumbar spinal stenosis (cLSS) presenting with RNR in the standing position (STA) were also investigated in supine (SUP) or neutral seated (SIT) and flexed seated (FLEX) positions. Additionally, 45 patients complaining of back pain and without MRI evidence of LSS were evaluated. Statistical significance was set at p < 0.05. RESULTS: Controls (A) and patients with cLSS (B) were comparable in terms of mean age (p = 0.88) and sex (p = 0.22). The progressive transition from STA to FLEX led to a comparable decrease in LL (p = 0.97), an increase in LSC (p = 0.80), and an increase in APD L1-L5 (p = 0.78). The APD of the stenotic level increased disproportionally between the different postures, up to 67% in FLEX compared to 29% in adjacent non-stenotic levels (p < 0.001). Therefore, the prevalence of RNR decreased to 49, 26, and 4% in SUP, SIT, and FLEX, respectively. CONCLUSION: The prevalence of RNR in standing position was underestimated by half in supine position. Body postures modified LL, LSC, and APD similarly in patients and controls. Stenotic levels compensated for insufficient intraspinal volume with a disproportionate enlargement when switching from the STA to FLEX.

Surgical Treatment of Multilevel Degenerative Cervical Myelopathy: Open-Door Laminoplasty and Fixation via Unilateral Approach. A Feasibility Study.

OBJECTIVE: We compared open-door laminoplasty via a unilateral approach and additional unilateral lateral mass screw fixation (uLP) with laminectomy and bilateral lateral mass screw fixation (LC) in the surgical treatment of multilevel degenerative cervical myelopathy (mDCM). METHODS: A retrospective cohort analysis of 46 prospectively enrolled patients (23 uLP and 23 LC). The minimum follow-up was 1 year. Neck and arm pains were evaluated with visual analog scales and disability with the Neck Disability Index (NDI). Myelopathy was rated with the modified Japanese Orthopaedic Association (mJOA) score. Cervical sagittal parameters were measured on plain and functional X-ray films with a specific software. The statistical significance was set at p < 0.05. Fusion was defined as <2 degrees of intersegmental motion on flexion/extension radiographs. RESULTS: The two groups were similar in age and comorbidities. The mean operation time and the mean hospital stay were shorter in the uLP group (p = 0.015). The intraoperative blood loss did not exceed 200 mL in both groups. At follow-up, the groups showed comparable clinical outcome data. The sagittal profile did not deteriorate in either group. Fusion rates were 67% in the uLP group and 92% in the LC group. No infections occurred in either group. In the LC group, one patient developed a transient C5 palsy. Revision surgery was required for a malpositioned screw (LC) and for one implant failure (uLP). CONCLUSION: Laminoplasty and unilateral fixation via a unilateral approach achieved comparable clinical and radiologic results with laminectomy and bilateral fixation, despite a lower fusion rate. However, the surgical traumatization was less.

Cervical Single-Level Pincer Stenosis Causing Myelopathy: A Technical Note and Medium-term Results of a One-Session Microsurgical 360-Degree Treatment.

BACKGROUND AND STUDY AIMS: Single-level circumferential or pincer stenosis (PS) affects few patients with degenerative cervical myelopathy (DCM). The surgical technique and medium-term results of a one-session microsurgical 360-degree (m360°) procedure are presented. PATIENTS: Between 2013 and 2018, the data of 23 patients were prospectively collected out of 371 patients with DCM. The m360° procedure comprised a microsurgical anterior cervical decompression and fusion (ACDF), with additional plate fixation, followed by flipping the patient and performing a microsurgical posterior bilateral decompression via a unilateral approach in crossover technique. RESULTS: The mean age of the patients was 72 years (range: 50-84); 17 patients were males. The mean follow-up time was 12 months (range: 6-31). The patients filled in the patient-derived modified Japanese Orthopaedic Association (P-mJOA) questionnaire on average 53 months after surgery. One patient received a two-level ACDF. Lesions were mostly (92%) located at the C3/C4 (8/24), C4/C5 (7/24), and C5/C6 (7/24) levels. Functional X-rays showed segmental instability in 10 of 23 patients (44%). All preoperative T2-weighted magnetic resonance imaging (MRI) showed an intramedullary hyperintensity. The median preoperative mJOA score was 13 (range 3), and it improved to 16 (range 3) postoperatively. The mean improvement rate in the mJOA score was 73%. When available, postoperative MRI confirmed good circumferential decompression with persistent intramedullary hyperintensity. There were two complications: a long-lasting radicular paresthesia at C6 and a transient C5 palsy. No revision surgery was required. CONCLUSION: The one-session m360° procedure was found to be a safe surgical procedure for the treatment of PS, and the medium-term clinical outcome was satisfactory.

The prevalence of redundant nerve roots in patients with lumbar spinal stenosis is body position dependent: a retrospective observational study with repeated measures design in an upright MRI scanner.

PURPOSE: Redundant nerve roots (RNRs) are a negative prognostic factor in patients with central lumbar spinal stenosis (LSS). Forty percent of candidates for surgical decompression show RNRs (RNR+) on preoperative conventional magnetic resonance imaging (MRI). We investigated the prevalence of RNRs in three functional postures (standing, neutral sitting and flexed sitting) with an upright MRI (upMRI). METHODS: A retrospective observational study with a repeated measures design. Thirty surgical candidates underwent upMRI. Sagittal and axial T2-weighted images of the three functional postures were evaluated. The segmental length of the lumbar spine (sLLS), the lordotic angle (LA) and the dural cross-sectional area (DCSA) were measured in each body position. Generalized linear mixed models were carried out. The 0.05 level of probability was set as the criterion for statistical significance. RESULTS: The prevalence of RNRs decreased from 80% during standing to 16.7% during flexed sitting (p < 0.001). The sLLS increased significantly from standing to neutral sitting in both RNR groups (p < 0.001). The increase from neutral sitting to flexed sitting was only significant (p < 0.001) for the group without RNRs (RNR-). The LA decreased significantly for both RNR groups from standing to flexed sitting (p < 0.001). The DSCA increased significantly in the RNR- group (p < 0.001) but not in the RNR+ group (p = 0.9). CONCLUSION: The prevalence of RNRs is body position dependent. Increases in DCSA play a determinant role in resolving RNRs.

Revision surgery in cervical spine.

PURPOSE: To report the indications, presurgical planning, operative techniques, complications for making decisions in cervical revision surgery (CRS). METHODS: Hundred and two patients underwent CRS over a four-year period. Epidemiological data, the type of first surgery, CRS surgical techniques and complications were retrospectively evaluated. Pain and neurological symptoms were assessed according to the validated Odom criteria. CRS indications were classified into five categories: adjacent segment disease (ASD), infection (INF), implant failure-pseudarthrosis (IFP), non-infectious complication, and deformity. Patients were classified into three groups, according to the approach of the index procedure: anterior, posterior, or 360°. RESULTS: The mean patient age was 63 years (59% males). ASD (40%), INF (23%), and IFP (22%) were observed in 85% of patients. CRS was performed with the same approach that was used in the index procedure in 64% of the anterior group and in 83% of the posterior group. In the 360° group, 64% of CRSs was performed with a posterior access. The early complication rate was 4.9%. The outcome was excellent in 19 patients (19%), good in 37 patients (36%), satisfactory in 27 patients (26%), and poor in six patients (6%). Thirteen patients (13%) were lost to follow-up. No implants failed radiologically or required surgical revision. CONCLUSIONS: CRS required painstaking planning and mastery of a variety of surgical techniques. The results were rewarding in half and satisfactory in a quarter of the patients. The complication rate was lower than expected. In the most complex cases, referral to a specialized center is recommended. These slides can be retrieved under Electronic Supplementary Material.

Degenerative Cervical Myelopathy: A 7-Letter Coding System That Supports Decision-Making for the Surgical Approach.

OBJECTIVE: To validate with a prospective study a decision-supporting coding system for the surgical approach for multilevel degenerative cervical myelopathy. METHODS: Ten cases were presented on an internet platform, including clinical and imaging data. A single-approach (G1), a choice between 2 (G2), or 3 approaches (G3) were options. Senior and junior spine surgeons analyzed 7 parameters: location and extension of the compression of the spinal cord, C-spine alignment and instability, general morbidity and bone diseases, and K-line and multilevel corpectomy. For each parameter, an anterior, posterior, or combined approach was suggested. The most frequent letter or the last letter (if C) of the resulting 7-letter code (7LC) suggested the surgical approach. Each surgeon performed 2 reads per case within 8 weeks. RESULTS: G1: Interrater reliability between junior surgeons improved from the first read (κ = 0.40) to the second (κ = 0.76, p < 0.001) but did not change between senior surgeons (κ = 0.85). The intrarater reliability was similar for junior (κ = 0.78) and senior (κ = 0.71) surgeons. G2: Junior/senior surgeons agreed completely (58%/62%), partially (24%/23%), or did not agree (18%/15%) with the 7LC choice. G3: junior/senior surgeons agreed completely (50%/50%) or partially (50%/50%) with the 7LC choice. CONCLUSION: The 7LC showed good overall reliability. Junior surgeons went through a learning curve and converged to senior surgeons in the second read. The 7LC helps less experienced surgeons to analyze, in a structured manner, the relevant clinical and imaging parameters influencing the choice of the surgical approach, rather than simply pointing out the only correct one.

Redundant nerve roots in lumbar spinal stenosis: inter- and intra-rater reliability of an MRI-based classification.

PURPOSE: Patients with central lumbar spinal stenosis (LSS) have a longer symptom history, more severe stenosis, and worse postoperative outcomes, when redundant nerve roots (RNRs) are evident in the preoperative MRI. The objective was to test the inter- and intra-rater reliability of an MRI-based classification for RNR. METHODS: This is a retrospective reliability study. A neuroradiologist, an orthopedic surgeon, a neurosurgeon, and three orthopedic surgeons in-training classified RNR on 126 preoperative MRIs of patients with LSS admitted for microsurgical decompression. On sagittal and axial T2-weighted images, the following four categories were classified: allocation (A) of the key stenotic level, shape (S), extension (E), and direction (D) of the RNR. A second read with cases ordered differently was performed 4 weeks later. Fleiss and Cohen's kappa procedures were used to determine reliability. RESULTS: The allocation, shape, extension, and direction (ASED) classification showed moderate to almost perfect inter-rater reliability, with kappa values (95% CI) of 0.86 (0.83, 0.90), 0.62 (0.57, 0.66), 0.56 (0.51, 0.60), and 0.66 (0.63, 0.70) for allocation, shape, extension, and direction, respectively. Intra-rater reliability was almost perfect, with kappa values of 0.90 (0.88, 0.92), 0.86 (0.84, 0.88), and 0.84 (0.81, 0.87) for shape, extension, and direction, respectively. Intra-rater kappa values were similar for junior and senior raters. Kappa values for inter-rater reliability were similar between the first and second reads (p = 0.06) among junior raters and improved among senior raters (p = 0.008). CONCLUSIONS: The MRI-based classification of RNR showed moderate-to-almost perfect inter-rater and almost perfect intra-rater reliability.

Patient demographics and MRI-based measurements predict redundant nerve roots in lumbar spinal stenosis: a retrospective database cohort comparison.

BACKGROUND: Up to 40% of patients diagnosed with lumbar spinal stenosis (LSS) show evidence of redundant nerve roots (RNR) of the cauda equina on their magnetic resonance images (MRI). The etiology of RNR is still unclear. Preoperative evidence of RNR is associated with a worse postsurgical outcome. Consequently, potential predictors of RNR could have a prognostic value. The aim was to test whether patient demographics and MRI-based measurements can predict RNR in LSS patients. METHODS: In a retrospective database-based cohort study the preoperative data of 300 patients, 150 with (RNR+) and 150 without (RNR-) evidence of RNR on their MRI were analyzed. Three independent researchers performed the MRI reads. Potential predictors were age, gender, body height (BH), length of lumbar spine (LLS), segmental length of lumbar spine (SLLS), lumbar spine alignment deviation (LSAD), relative LLS (rLLS), relative SLLS (rSLLS), number of stenotic levels (LSS-level), and grade of LSS severity (LLS-grade, increasing from A to D). Binomial logistic regression models were performed. RESULTS: RNR+ patients were 2.6 years older (p = 0.01). Weak RNR+ predictors were a two-years age increase (OR 1.06; p = 0.02), 3 cm BH decrease (OR 1.09; p = 0.01) and a 5 mm SLLS decrease (OR 1.34; p < 0.001). Strong RNR+ predictors were a 1% rLLS decrease (OR 2.17; p < 0.001), LSS-level ≥ 2 (OR 2.59; p = 0.001), LLS-grade C (OR 5.86; p = 0.02) and LLS-grade D (OR 18.4; p < 0.001). The mean rSLLS of RNR+ patients was 0.6% shorter (p < 0.001; 95% C.I. 0.4 to 0.8) indicating a disproportionate shorter lumbar spine. CONCLUSIONS: We identified LSS severity grade and LSS levels as the strongest predictors of RNR. In addition to previous studies, we conclude that a shortened lumbar spine by degeneration is involved in the development of RNR.

The clinical significance of redundant nerve roots of the cauda equina in lumbar spinal stenosis patients: A systematic literature review and meta-analysis.

OBJECTIVES: Decompression surgery for lumbar spinal stenosis (LSS) is the most performed spine surgery procedure in patients older than 65 years. Around 40% of LSS patients scheduled for decompression surgery have evidence of redundant nerve roots (RNR) of the cauda equina on their magnetic resonance images (MRI). Little is known about the clinical significance of RNR in LSS patients. The objective was to assess the effects of RNR on clinical scores and recovery in older adults diagnosed with LSS. PATIENTS AND METHODS: A systematic literature search was performed in April 2018 on PubMed, Web of Science, MEDLINE and Cumulative Index to Nursing and Allied Health Literature (CINAHL). Prospective and retrospective cohort studies undertaken to assess differences in clinical outcomes in patients diagnosed with LSS with versus without evidence of RNR on their MRIs were selected. Two authors independently selected studies, abstracted data and assessed risk of bias. We calculated weighted mean differences (WMD) for continuous variables and odds ratio (OR) for variables reported in frequencies. RESULTS: Seven studies comprising a total of 1046 LSS patients were included in the meta-analysis. LSS patients with evidence of RNR (RNR+) were older, WMD 5.7 95% CI [2.2-9.2], p = 0.001, had smaller cross sectional area (CSA) of the stenotic level, WMD -12.2 95% CI [-17.7 to -6.7], p < 0.0001 and longer symptom onset duration, WMD 13.2 95% CI [-0.2-26.7], p = 0.05. The pooled preoperative clinical score in the RNR + group was worse but the difference was not statistically significant, WMD -3.8 95% CI [-7.9 to 0.2], p = 0.07. After decompression surgery RNR + patients had worse clinical scores, -4.7 95% CI [-7.3 to -2.1], p = 0.0004 and lower recovery rates, -9.8 95% CI [-14.8 to -4.7], p = 0.0001. CONCLUSION: There is limited quality evidence that RNR + patients are older, have a longer symptom history and present higher degrees of lumbar stenosis as given by the narrow CSA in comparison to RNR- patients. After decompression surgery RNR + patients have worse clinical scores and lower recovery rates. In view of these results RNR can be seen as a negative prognostic factor in LSS patients.

A retrospective analysis of bone mineral status in patients requiring spinal surgery.

BACKGROUND: Impaired bone quality is associated with poor outcome of spinal surgery. The aim of the study was to assess the bone mineral status of patients scheduled to undergo spinal surgery and to report frequencies of bone mineral disorders. METHODS: We retrospectively analyzed the bone mineral status of 144 patients requiring spinal surgery including bone mineral density by dual-energy X-ray absorptiometry (DXA) as well as laboratory data with serum levels of 25-hydroxyvitamin D (25-OH-D), parathyroid hormone, calcium, bone specific alkaline phosphate, osteocalcin, and gastrin. High-resolution peripheral quantitative computed tomography (HR-pQCT) was additionally performed in a subgroup of 67 patients with T-Score below - 1.5 or history of vertebral fracture. RESULTS: Among 144 patients, 126 patients (87.5%) were older than 60 years. Mean age was 70.1 years. 42 patients (29.1%) had suffered from a vertebral compression fracture. 12 previously undiagnosed vertebral deformities were detected in 12 patients by vertebral fracture assessment (VFA). Osteoporosis was present in 39 patients (27.1%) and osteopenia in 63 patients (43.8%). Only 16 patients (11.1%) had received anti-osteoporotic therapy, while 54 patients (37.5%) had an indication for specific anti-osteoporotic therapy but had not received it yet. The majority of patients had inadequate vitamin D status (73.6%) and 34.7% of patients showed secondary hyperparathyroidism as a sign for a significant disturbed calcium homeostasis. In a subgroup of 67 patients, severe vertebral deformities were associated with stronger deficits in bone microarchitecture at the distal radius compared to the distal tibia. CONCLUSIONS: This study shows that bone metabolism disorders are highly prevalent in elderly patients scheduled for spinal surgery. Vertebral deformities are associated with a predominant deterioration of bone microstructure at the distal radius. As impaired bone quality can compromise surgical outcome, we strongly recommend an evaluation of bone mineral status prior to operation and anti-osteoporotic therapy if necessary.

Incidental durotomy in spine surgery: first aid in ten steps.

INTRODUCTION: Incidental durotomy (ID) is the most common complication of spine surgery. Revision procedures, ossification of the yellow ligament, or synovial cysts are well-known risk factors. The size, shape, and severity of ID are unpredictable, ranging from a pinpoint hole to a several centimeters large dural laceration with transected fibers following the slippage of a cutting burr. Furthermore, the occurrence of ID is always unexpected. Intra-operative management is often based on a steep learning curve rather than a structured scheme. PURPOSE: To provide an intra-operative ten-step closure technique (10ST) for IDs of varying severity. METHODS: A database of 4020 consecutive surgeries for lumbar degenerative disease over the past 4 years was searched for ID. The records of 176 patients were analyzed. Two dural repair techniques were compared: the "individual" technique (InT) and the 10ST. RESULTS: The overall prevalence of ID was 4.4%. The prevalence was lowest in virgin micro-discectomies (1.7%) and ranged from 3.6% in decompression for spinal canal stenosis up to 14.5% in revision procedures. All surgeries were performed with the aid of a microscope. Among 107 primary surgeries, the InT achieved a single-stage closure of the ID in 96 procedures (89.7%). Among 20 virgin surgeries, the 10ST was successful in all cases (P = 0.21). Among 42 re-do procedures following failed attempts to stop cerebrospinal fluid (CSF) leakage, the InT achieved single-stage closure in 36 procedures (85.7%). The 10ST was successful in all 26 cases (P = 0.03). The follow-up was 1 year. CONCLUSIONS: The 10ST should be considered for successful single-stage closure in primary repair of ID.

Anatomic midline marking during cervical arthroplasty with ProDisc-C: an alternative, simple, and reliable method: technical note.

STUDY DESIGN: Retrospective study. OBJECTIVE: To report the results of a different, and previously undescribed, technique to anatomically mark the midline during cervical arthroplasty. SUMMARY OF BACKGROUND DATA: The ProDisc-C prosthesis should be implanted in the vertebral body midline. Current standard technique for midline marking usually relies on intraoperative fluoroscopy to locate on anteroposterior (AP) x-rays a midpoint between the uncinate processes and superimposed to the intervening spinous process. Nevertheless, uncinate process can be used as anatomic landmarks to size the proper width of the prosthesis and implant a suitable device well centered in the midline. METHODS: Two groups of ProDisc-C prostheses were analyzed and compared for midline alignment. Group 1: 68 prostheses were implanted using a different technique to identify the anatomic midline. Soft disc hernia and/or spondylotic disease (whose degree was not a contraindication for arthroplasty), either at single or multiple levels, were the underlying diseases. Group 2: 19 ProDisc-C implanted using the standard fluoroscopic technique to mark the midline. RESULTS: Postoperative analysis of AP digital x-rays revealed in group 1a mean difference of -0.35 mm between the 2 halves of the prosthesis' inferior plate in respect to the defined midline. Sixty prostheses (88.2%) had an eccentric position ranging between 0.1 and 2.2 mm. Five prostheses (7.3%) were in a more significantly eccentric position by 4 to 5.5 mm. In 3 cases (4.4%), the eccentric positioning was between 2.5 and 4 mm. SD was + or - 2.18. In group 2, the mean difference was -0.07 mm. Only 1 prosthesis (5.2%) was in eccentric position by 6.14 mm. Five devices (26.3%) were in eccentric position by > or = 2 mm. The remaining 13 prostheses (68.4%) showed an eccentric position ranging between 0.36 and 1.82 mm. SD was + or - 2.02. Statistical analysis was performed using the Student t test. CONCLUSIONS: This study confirms that in cases of soft disc hernia or moderate spondylosis, the anatomic midline marking technique is a safe, reliable, and effective option. It is as accurate as the current fluoroscopic-guided technique and gives the opportunity either to reduce patient's and surgeons' exposure to radiations or to shorten the operation time by reducing the overall fluoroscopy and avoiding performing AP x-rays.

Lumbar spinal stenosis: prognostic factors for bilateral microsurgical decompression using a unilateral approach.

OBJECTIVE: We describe a prospective cohort study that investigated the effectiveness of microsurgical bilateral decompression using unilateral laminotomy for lumbar spinal stenosis and assessed the factors influencing the outcome. METHODS: A total of 165 consecutive patients underwent decompression for lumbar spinal stenosis. They were divided into 3 age groups: A (<65 years), B (65-75 years), and C (>75 years). Further classification was performed according to body mass index (BMI): BMI 1 (<26), BMI 2 (26-30), and BMI 3 (>30), anesthesiological risk factors (American Society of Anesthesiologists), and the number of levels decompressed. The outcome was monitored by an independent observer at 1 week, 3 months, and 1 year after surgery. The following parameters were evaluated: pain (visual analog scale and analgesic consumption), functional improvement (Neurogenic Claudication Outcome Score), and walking performance, defined as walking distance x speed (treadmill). RESULTS: One week after surgery, pain decreased in 85.9% of patients, and a comparison of the pre- and postoperative use of analgesics showed that 38% of nonopioid use and 74% of opioid use were discontinued, whereas nonsteroidal anti-inflammatory drug consumption increased 13%. One year after surgery, pain remained decreased in 83.9% of patients, Neurogenic Claudication Outcome Score increased in 90.3% of patients, and walking performance improved in 92.2% of patients. BMI greater than 30 was the only negative prognostic factor for pain reduction (P = 0.012) and Neurogenic Claudication Outcome Score improvement (P = 0.019). Surprisingly, patients who underwent multilevel decompression benefitted more from surgery than those who underwent single-level decompression. CONCLUSION: Microsurgical bilateral decompression using unilateral laminotomy is an effective surgical option for lumbar spinal stenosis, even in high-risk patients with multilevel stenosis.

The translaminar approach to lumbar disc herniations impinging the exiting root.

OBJECTIVE: We undertook a prospective, non-randomized study on the translaminar approach for the treatment of cephalad extruded disc fragments impinging the exiting root. METHODS: Between May 2000 and July 2004, 104 patients (59 men)-presenting with upper lumbar root compression in 74% of the cases -underwent a translaminar approach. The mean age was 57 years (range, 27-80 yr). The lamina was approached either through the conventional subperiosteal route or via a muscle splitting access. Mostly intraforaminal disc fragments were removed through a translaminar hole 10 mm in diameter, and the disc space was cleared in cases of evident perforation of the annulus. Follow-up examinations were performed by an independent observer at 1 and 6 weeks; 3, 6, and 12 months; and once yearly thereafter (mean follow-up period, 32 mo). RESULTS: Extruded (61%) or subligamentous (39%) disc fragments were found intra-operatively. Laminae L4 (44%) and L5 (26%) were mostly involved. In eight cases, the translaminar hole was enlarged to a conventional laminotomy. In 13 patients, the disc space was cleared. The outcomes according to the Macnab criteria were excellent (67%), good (27%), fair (5%), and poor (1%). The incidence of recurrent disc herniations was 7%. Functional radiography performed in the first 20 patients 6 months after surgery and an additional 12 patients complaining of postsurgical back pain excluded any instability. CONCLUSION: The translaminar approach is recommended in disc herniations encroaching the exiting root, as an alternative to the conventional interlaminar route.

Lumbar microdiscectomy: subperiosteal versus transmuscular approach and influence on the early postoperative analgesic consumption.

Conventional lumbar microdiscectomy requires subperiosteal dissection of the muscular and tendineous insertions from the midline structures. This prospective, randomized, single center trial aimed to compare a blunt splitting transmuscular approach to the interlaminar window with the subperiosteal microsurgical technique. Two experienced surgeons performed first time lumbar microdiscectomy on 125 patients. The type of approach and retractor used was randomized and both patients and evaluator were blinded to it. In 59 patients a speculum-counter-retractor was inserted through a subperiosteal (SP) route and in 66 patients an expandable tubular retractor was introduced via a transmuscular (TM) approach. In both groups the mean age was 51 years, the male gender prevalent (61%) and the distribution of the operated levels was similar. The outcome measures were VAS for back and leg pain, ODI and the postoperative analgesic consumption was scored by the WHO 3-class protocol. A postsurgical VAS (0-1) was defined as excellent, VAS (2-4) as satisfactory result. In this study the patients scored from 1 to 3 points daily according to the class of drugs taken. Furthermore, a 1/3 point (class 1), 2/3 point (class 2) and 1 point (class 3) was added for each on-demand drug intake. Recovery from radicular pain was excellent (SP 68%, TM 76%) or satisfactory (SP 23%, TM 21%). Recovery from back pain was excellent (SP 58%, TM 59%) or satisfactory (SP 37%, TM 37%). Postoperative mean improvement ODI was: SP 29% and TM 31%. Postoperative mean analgesic intake: SP 4.8 points, TM 2.6 points (P = 0.03). Lumbar microdiscectomy improves pain and ODI irrespective of the type of approach and retractor used. However, the postsurgical analgesic consumption is significantly less if a tubular retractor is inserted via a transmuscular approach.