Lumbar Reconstruction Research Articles

Lumbar reconstruction with hyperlordotic cages: Prediction of neuroforaminal height in comparison to established age and sex dependent reference values

Interbody cages are routinely used in lumbar reconstruction surgery of deformity cases for restoration of lordosis and sagittal balance of the spine. However, if hyperlordotic implants are inserted into the intervertebral space, special consideration has to be taken concerning the height of the neural foramen during cage implantation. The greater the lordotic angle of the cage is, the higher the posterior size of the cage needs to be in order to avoid neuroforaminal nerve root impingement. In this technical communication, we propose and clinically validate a stepwise mathematic model to predict neuroforaminal height in patients undergoing lumbar reconstruction with hyperlordotic cages. The length of the superior and inferior vertebral end plates including the height of the neural foramen are measured before implantation of the cage in standing sagittal view x-rays. By assumption of an isosceles triangle in combination with the posterior height and the lordotic angle of the cage, the neuroforaminal height after cage implantation can be estimated. By comparison of the predicted neuroforaminal height with age and sex dependent reference values, nerve root impingement can be avoided by selection of the necessary posterior height of the hyperlordotic cage while still gaining sufficient lumbar lordosis.

Minimally Invasive Approach for Degenerative Spondylolisthesis: Lateral Single-Position Surgery with Intraoperative Computed Tomography Navigation and Fluoroscopy: A Technical Note

Degenerative spondylolisthesis (DS) is a prevalent condition that leads to low back pain and neurological symptoms. This technical note presents a novel surgical strategy for treating DS using lateral single-position surgery (SPS) in combination with intraoperative computed tomography navigation and fluoroscopy. Fifteen patients (5 males and 10 females, mean age 70.2years) diagnosed with DS with a slip of 5mm or more underwent lateral lumbar interbody fusion (LLIF) with percutaneous pedicle screw (PPS) fixation using this technique. The procedure involved slip reduction using an upside PPS and rod fixation, followed by LLIF performed in the same lateral position. The term "upside PPS" refers to a PPS that is inserted on the ceiling side of the patient's surgical field. Preoperative and postoperative radiographic assessments were conducted to evaluate the effectiveness of the lateral SPS. The results demonstrated significant improvements in various parameters, including spondylolisthesis reduction, segmental lordosis, disc height, and spinal canal dimensions. The lateral-SPS procedure exhibited several advantages over traditional flip LLIF approaches for slip reduction. Additionally, the technique provided accurate intraoperative navigation guidance through computed tomography imaging, ensuring precise implant placement and slip reduction. Combining LLIF and PPS fixation in a single procedure presents a precise, efficient approach for DS treatment, minimizing repositioning needs. This technique enables effective lumbar reconstruction, restoration of spinal stability, and improved patient outcomes. Although further investigation is warranted, lateral SPS surgery may hold promise as an innovative solution for managing DS by reducing surgical invasiveness and optimizing surgical efficiency.

92. Distinctions between two-year recovery patterns and outcomes in circumferential lumbar reconstructions based on surgical positioning: comparative analysis of single-position vs staged vs same day approaches

<h3>BACKGROUND CONTEXT</h3> Versatility in patient positioning during spine surgery has recently gained popularity. This includes single-position circumferential minimally invasive surgery, staged and same-day procedure. Overall analysis of outcomes between these approaches is lacking in the literature. <h3>PURPOSE</h3> To investigate the perioperative and postoperative outcomes of single-position, staged or same-day patients. <h3>STUDY DESIGN/SETTING</h3> Retrospective review of a single-center database. <h3>PATIENT SAMPLE</h3> This study included 580 spine fusion patients. <h3>OUTCOME MEASURES</h3> Complications, health-related quality of life (HRQL) alignment. <h3>METHODS</h3> Operative spine patients with available baseline (BL) and up to 2-year (2Y) radiographic and HRQL data were included. Patients were stratified into three different categories based on surgical approach: single-position (SP), staged (ST), and same-day (SD). ANCOVA analysis was used to assess differences in demographic, radiographic, clinical, surgical factors and outcomes. <h3>RESULTS</h3> A total of 133 patients were included (age 57.8±11.4, BMI 30.6±7, 42% female, ASA 2.36±.57). Patients had an average of 2.42±1.3 levels fused, operative time was 293±141 minutes, EBL was 326±325, most common UIV was L3, and LIV was L5. Mean LOS was 5±4 days. Fifty-six patients were SP, 30 patients ST, and 47 were SD. SP patients were older on average (SP: 62, ST: 56, and SD: 55, <.05), had a lower BMI (SP: 29, S: 32, SD 32, p <.05) and lower mean ASA (SP: 2.2, ST: 2.5, SD: 2.5 p=.094). ST patients had a greater baseline T1PA (SP: 17.7, ST: 23.3, SD: 18.6, p=.11), with lower PI-LL (SP: 3.5, ST: .5, SD: 9.5, p=.06), PT (SP: 20.7, ST: 15.3, SD: 19.4, p=.03), and LL (SP: 55, ST: 56, SD: 48, p=.06). Prior fusion was more common among ST (SP: 29%, ST: 47%, SD 19% p=.033). ST patients had a lower number of levels fused (SP: 2.1, ST: 2.6, SD: 2.7, p=.037). ST patients had a greater amount of interbody fusions (SP: 1.53, ST: 2.3, SD: 1.9, p=.012). SD patients had a greater amount of osteotomies (SP: 14%, ST: 7%, SD: 74%, p <.001), corpectomies (SP: 2%, ST: 7%, SD: 41%, p <.001), and decompressions (SP: 57%, ST: 66%, SD: 100%, p <.001). SP patients had a lower operative time (SP: 386 min, ST: 652, SD: 498, p=.059), lower EBL (SP: 296 ml, ST: 498 ml, SD: 418 ml, p <0.001), and shorter LOS (SP: 4.53, ST: 8.15, SD: 5.71, p=.022). SD approach resulted in more patients going to rehab postoperatively (SP:7%, ST: 8%, SD: 29%, p=.030). SP patients had a lower NRS back score (SP: 3.2, ST: 4, SD: 6, p=.011), and lower NRS leg score (SP: 2.6, ST: 3.5, SD: 4.7, p=.118). Patients had a comparable postoperative T1PA, PI-LL, PT, and LL, with a comparable degree of correction. SP patients had a lower amount of pulmonary, GI/renal complications, and underwent fewer reoperations compared to ST and SD patients. <h3>CONCLUSIONS</h3> Although the SP alternative for circumferential lumbar reconstruction surgery has demonstrated good patient outcomes in the degenerative lumbar spondylosis population, few studies exist comparing outcomes of single position to those of more traditional dual positioning approaches. This study demonstrates that SP is associated with significant improvements in perioperative outcomes, reoperation rates, and pain scores when compared to both the staged and same-day manner of dual positioning with comparable degrees of correction. SP may prove to be a superior approach for certain degenerative spondylosis patients and warrants further studies to determine ideal patient candidacy and elucidate long-term outcomes. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Lateral interbody release for fused vertebrae via transpsoas approach in adult spinal deformity surgery: a preliminary report of radiographic and clinical outcomes

BackgroundLateral interbody release (LIR) via a transpsoas lateral approach is a surgical strategy to address degenerative lumbar scoliosis (DLS) patients with anterior autofusion of vertebral segments. This study aimed to characterize the clinical and radiographic outcomes of this lumbar reconstruction strategy using LIR to achieve anterior column correction.MethodsData for 21 fused vertebrae in 17 consecutive patients who underwent LIR between January 2014 and March 2020 were reviewed. Demographic and intraoperative data were recorded. Radiographic parameters were assessed preoperatively and at final follow-up, including segmental lordotic angle (SLA), segmental coronal angle (SCA), bone union rate, pelvic incidence (PI), lumbar lordosis (LL), pelvic tilt, sacral slope, PI-LL mismatch, sagittal vertical axis, Cobb angle, and deviation of the C7 plumb line from the central sacral vertical line. Clinical outcomes were evaluated using Oswestry Disability Index (ODI), visual analog scale (VAS) scores for low back and leg pain, and the short form 36 health survey questionnaire (SF-36) postoperatively and at final follow-up. Complications were also assessed.ResultsMean patient age was 70.3 ± 4.8 years and all patients were female. Average follow-up period was 28.4 ± 15.3 months. Average procedural time to perform LIR was 21.3 ± 9.7 min and was not significantly different from traditional lateral interbody fusion at other levels. Blood loss per single segment during LIR was 38.7 ± 53.2 mL. Fusion rate was 100.0% in this cohort. SLA improved significantly from − 7.6 ± 9.2 degrees preoperatively to 7.0 ± 8.8 degrees at final observation and SCA improved significantly from 19.1 ± 7.8 degrees preoperatively to 8.7 ± 5.9 degrees at final observation (P < 0.0001, and < 0.0001, respectively). All spinopelvic and coronal parameters, as well as ODI and VAS, improved significantly. Incidence of peri- and postoperative complications such as iliopsoas muscle weakness and leg numbness in patients who underwent LIR was as much as XLIF. Incidence of postoperative mechanical failure following LIR was also similar to XLIF. Reoperation rate was 11.8%. However, there were no reoperations associated with LIR segments.ConclusionsThe LIR technique for anterior column realignment of fused vertebrae in the context of severe ASD may be an option of a safe and effective surgical strategy.

Transforaminal Lumbar Interbody Fusion versus Posterolateral Fusion for Surgical Treatment of Segmental Lumbar Spinal Instability

Background Data: The rationale behind lumbar fusion surgery is to eliminate pathologic segmental motion and its accompanying symptoms, especially low back pain.Posterolateral fusion (PLF) using pedicle screw fixation (PSF) has been one of the most popular procedures among the posterior lumbar reconstruction techniques.Lumbar interbody fusion is a recognized surgical technique in treating chronic low back pain in segmental instability. Purpose: The purpose of this study was to compare the clinical and radiological outcomes of stabilizing the lumbar spine using TLIF versus PLF for lumbar segmental instability. Study Design: A prospective, nonrandomized clinical controlled trial. Patients and Methods: Forty patients with segmental lumbar instability were divided into two groups: TLIF and PLF groups, with twenty patients each. Top loaded pedicle screw construct was used with both groups. The mean age of the patients was 48.35 years in the TLIF group and 45.3 years in the PLF group. Sex distribution was 6 males and 14 females in the TLIF group and 7 males and 13 females in the PLF group. Mechanical low back pain was the chief complaint in all patients. Sciatica was a complaint in 12 patients (60%) of the TLIF group and 13 (65%) patients of the PLF group. Patients were evaluated pre- and postoperatively by visual analogue scale (VAS), Oswestry disability index (ODI), and radiographs. Results: The average operative time was 214.5 minutes in the TLIF group and 192.5 minutes in the PLF group. The mean estimated blood loss was 278 ml in the TLIF group and 259 ml in the PLF group. The average length of hospital stay was 3.85 days in the TLIF group and 3.8 days in the PLF group. Patients progressively improved regarding VAS and ODI in both groups with no statistically significant difference except for VAS for back pain, where the TLIF group gave better results. However, TLIF group gave better results in patients with postlaminectomy instability than the PLF group. Solid fusion occurred in 17 patients (85%) of the TLIF group and 16 patients (80%) of the PLF group with no statistical difference. Conclusion: Both transforaminal lumbar interbody fusion and posterolateral fusion are effective and safe options for treating segmental lumbar instability. However, interbody fusion yield superior results in patients with postlaminectomy instability. (2021ESJ253)

Lateral lumbar interbody fusion after reduction using the percutaneous pedicle screw system in the lateral position for Meyerding grade II spondylolisthesis: a preliminary report of a new lumbar reconstruction strategy

BackgroundUtilization of a cage with a large footprint in lateral lumbar interbody fusion (LLIF) for the treatment of spondylolisthesis leads to a high fusion rate and neurological improvement owing to the indirect decompression effect and excellent alignment correction. However, if an interbody space is too narrow for insertion of an LLIF cage for cases of spondylolisthesis of Meyerding grade II or higher, LLIF cannot be used. Therefore, we developed a novel strategy, LLIF after reduction by the percutaneous pedicle screw (PPS) insertion system in the lateral position (LIFARL), for surgeons to perform accurate and safe LLIF with PPS in patients with such pathology. This study aimed to introduce the new surgical strategy and to present preliminary clinical and radiological results of patients with spondylolisthesis of Meyerding grade II.MethodsSix consecutive patients (four men and two women; mean age, 72.7 years-old; mean follow-up period, 15.3 months) with L4 spondylolisthesis of Meyerding grade II were included. Regarding the surgical procedure, first, PPSs were inserted into the L4 and L5 vertebrae fluoroscopically, and both rods were placed in the lateral position. The L5 set screws were fixed tightly, and the L4 side of the rod was floated. Second, the L4 vertebra was reduced by fastening the L4 set screws so that they expanded the anteroposterior width of the interbody space. At that time, the L4 set screws were not fully tightened to the rods to prevent the endplate injury. Finally, the LLIF procedure was started. After inserting the cage, a compression force was added to the PPSs, and the L4 set screws were completely fastened.ResultsThe mean operative time was 183 min, and the mean blood loss was 90.8 mL. All cages were positioned properly. Visual analog scale score and Oswestry disability index improved postoperatively. Bone union was observed using computed tomography 12 months after surgery.ConclusionFor cases with difficulty in LLIF cage insertion for Meyerding grade II spondylolisthesis due to the narrow anteroposterior width of interbody space, LIFARL is an option to achieve LLIF combined with posterior PPS accurately and safely.Trial registrationUMIN-Clinical Trials Registry, UMIN000040268, Registered 29 April 2020, https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000045938

A novel lumbar total joint replacement may be an improvement over fusion for degenerative lumbar conditions: a comparative analysis of patient-reported outcomes at one year

Background contextEffective alternatives to lumbar fusion for degenerative conditions have remained elusive. Anterior total disc replacement does not address facet pathology or central/recess stenosis, resulting in limited indications. A posterior-based motion-preserving option that allows for neural decompression, facetectomy, and reconstruction of the disc and facets may have a role. PurposeThe purpose was to compare one-year patient-reported outcomes for a novel, all-posterior, lumbar total joint replacement (LTJR – replacing both the disc and facet joints) against transforaminal lumbar interbody fusion (TLIF) for degenerative lumbar conditions warranting fusion (degenerative spondylolisthesis, recurrent disc herniation, severe foraminal stenosis requiring facet removal, and adjacent segment degeneration). Study design/settingA retrospective analysis of prospectively collected data comparing outcomes for LTJR patients to TLIF patients at an academic teaching hospital. Patient sampleAnalysis was conducted on 156 adult TLIF patients who were propensity matched to the 52 LTJR patients for a total sample of 208. Outcome measuresSelf-reported Oswestry Disability Index (ODI) and Numeric Rating Scale (NRS) for back and leg pain were compared preoperatively, 3 months and 1 year after surgery. MethodsThe implant is a motion-preserving lumbar reconstruction that replaces the function of both the disc and facets and is implanted using a bilateral transforaminal approach with complete facetectomies. Adult patients with degenerative lumbar pathology undergoing either LTJR or open TLIF were analyzed. These degenerative conditions included: grade 1 degenerative spondylolisthesis, recurrent disc herniation, adjacent segment disease, disc degeneration with severe foraminal stenosis). Trauma, tumor, grade 2 or higher spondylolisthesis, spinal deformity, and infection cases were excluded. Propensity score matching was performed to ensure parity between the cohorts. Multivariable regression analyses were done to compare the 1-year results as measured by 3 different standards to assess procedure success. ResultsAt 3 months, both the LTJR and TLIF cohorts showed significant and similar improvements in ODI and NRS back and leg pain. At 1 year, the LTJR cohort showed continued improvement in ODI and NRS back pain, while the TLIF group showed a plateau for ODI, back and leg pain. In a series of three multivariable logistic regressions, LTJR was shown to provide 3.3 times greater odds of achieving the minimal clinical symptom state in disability and pain (ODI <20%, NRS back and leg pain <2) and 2.4 and 4.1 times greater odds of achieving substantial clinical benefit (18% reduction in ODI) and minimal clinically important difference (30% reduction in ODI) as compared to TLIF. ConclusionsHere we present a comparative analysis for the first 52 patients undergoing a novel, posterior-based LTJR for the lumbar spine versus TLIF for degenerative pathology. The approach for the LTJR allows for wide neural decompression, facetectomy, and complete discectomy, with the implant working to replace the function of the disc and facets to preserve motion. At 1 year, the LTJR cohort showed significant improvement in ODI and NRS back and leg pain as compared to TLIF. These results suggest that wide neural decompression combined with motion preservation using this novel LTJR may represent a viable alternative to TLIF for treating certain degenerative conditions. A prospective controlled trial is under development to further evaluate the efficacy, safety, and durability of this procedure.

Biomechanical characterization of vertebral body replacement in situ: Effects of different fixation strategies

Background and ObjectiveArtificial vertebral implant with a lateral or posterior screw-rod fixation system are usually employed in lumbar reconstruction surgery to rebuild the lumbar spine after partial resection due to a tumor or trauma. However, few studies have investigated the effect of the various fixation systems on the biomechanics of the reconstructed lumbar system. This study aims to evaluate the influence of different surgical fixation strategies on the biomechanical performance of a reconstructed lumbar spine system in terms of the strength and long-term stability. MethodsTwo typical lumbar spine reconstruction case models that correspond to lateral or posterior fixation systems were built based on the clinical data. Finite element analyses were performed, and comparisons were made between the two models based on the predicted stress distribution of the reconstructed lumbar spine model, bone-growth area of the endplate, and the range of motion under various normal daily activities. ResultsThe load from the upper vertebral body was found to be effectively transmitted onto the lower vertebral body by a vertebral implant with the lateral fixation system; this was favorable for bone growth after surgery. However, significantly high stresses were concentrated around the interaction region between the screws and bone, owing to the uneven lateral fixation structure; this may increase the risk of bone fractures and screw loosening in the long term. For the posterior fixation case, stably posterior fixation structure was favorable to maintain stability for the reconstructed lumbar spine. However, the load was mainly transmitted via the fixation rod rather than the vertebral implant, owing to the stress shielding effect. Therefore, the predicted strain on the endplate were insufficient for bone ingrowth under most of the spinal activates, which could cause bone loss and prosthesis loosening. ConclusionsIn this study, the comparisons of the reconstructed lumbar spine system with lateral and posterior fixation strategies were conducted. The Pros and Cons of these two fixation strategies was deeply discussed and the associated clinical issues were provided. The results of this study will have a clear impact in understanding the biomechanics of the lumbar spine with different fixation strategies and providing necessary instructions to the design and application of the lumbar spinal fixation system.

249. A novel posterior total joint replacement for the lumbar spine as an alternative to fusion: pilot data for the first 84 patients

BACKGROUND CONTEXT Effective alternatives to degenerative lumbar fusion have remained elusive. Fusion frequently results in adjacent level disease, reoperation, poor outcomes, and high costs. Anterior total disc replacement (TDR) does not address facet pathology or neural compression; thus, indications are limited. There is a need for a posterior-based motion-sparing option that allows for neural decompression, facetectomy, and disc replacement. PURPOSE To present the pilot data for the first 84 patients undergoing posterior lumbar total joint replacement for common degenerative conditions. STUDY DESIGN/SETTING Prospective case series. PATIENT SAMPLE Adult patients (age 18-79 years) with degenerative lumbar pathology were treated. Diagnoses included: degenerative spondylolisthesis, recurrent disc herniation, degenerative disc disease, foraminal stenosis, and central lumbar stenosis. Tumor, trauma, and infection cases were excluded. OUTCOME MEASURES Oswestry Disability Index (ODI), visual analogue scale (VAS) for back and leg pain, and opioid use. METHODS The implant is a motion-sparing lumbar reconstruction that replaces the function of both the disc and facets and is implanted using a bilateral trans-foraminal (TLIF) approach with complete facetectomies. For this IRB-approved pilot study, 84 adult patients (mean age 52.49) with degenerative lumbar pathology were treated. Diagnoses included: degenerative spondylolisthesis, recurrent disc herniation, degenerative disc disease, foraminal stenosis, and central lumbar stenosis. Tumor, trauma, and infection cases were excluded. ODI, VAS for back and leg pain, and opioid use were collected at baseline, 3 months, 6 months, and 1 year, with radiographs obtained at each time point. To date, follow up data is available for 70 patients at 3 months, 54 at 6 months, and 38 patients at 1 year. RESULTS A total of 125 levels were treated: L4-5 (57), L5-S1 (41), L3-4 (22), L2-3 (4), and L1-2 (1). Forty-seven patients had one level, 33 had two levels, and four patients had three levels treated. ODI improved significantly at each time interval following surgery (46.58 preop, 23.91 at 3 months, 18.87 at 6 months, and 13.80 at 1 year). VAS back and leg pain (calculated as the highest reported VAS score multiplied by the frequency of that pain level) also improved at each time point, from an average value of 51.59 at baseline to 17.40 at 3 months, 13.64 at 6 months, and 11.39 at 1 year. Minimal symptom state (ODI ≤ 20 and VAS back and leg pain ≤ 20) was maintained by 18 out of 27 one-level patients (67%), and by 7 out of 10 two-level patients (70%) at 1 year. Opioid usage was CONCLUSIONS Here we present pilot data for the first 84 patients undergoing a novel, posterior-based total joint replacement for the lumbar spine using a TLIF approach with complete facetectomies. The approach allows for wide neural decompression, facetectomy, and complete discectomy, with the implant working to replace the function of the disc and facets to preserve motion. ODI and VAS back/leg pain scores improved significantly at each time interval following surgery. At 1 year, a high percentage (66%) of patients have maintained a minimal symptom state, which is a significant improvement compared with the fusion literature where a recent study reported 18% of 396 patients maintained a minimal symptom state after 1 year following fusion. The greatest theoretical benefit of this device is preservation of lumbar motion segments resulting in more physiologic lumbar motion and the potential to decrease the risk for adjacent segment disease. Ongoing long-term follow-up is underway to evaluate the durability of this procedure and the impact on adjacent segments. FDA DEVICE/DRUG STATUS 3Spine BalancedBack Lumbar Joint Replacement (Investigational/Not approved)

CLINICAL AND RADIOLOGIC OUTCOMES OF TWO TYPES OF CAGES USED IN THE TREATMENT OF DEGENERATIVE LUMBAR DISEASES: NOVEL TITANIUM CAGES VERSUS PEEK CAGES

Purpose: This study reports the clinical effects of [Formula: see text]-shaped titanium cages (ReBorn Essence Z-Brace cages) and compares the clinical outcomes between [Formula: see text]-shaped titanium cages (ZTC group) and polyetheretherketone cages (PEEK cages, PK group) for the application in transforaminal lumbar interbody fusion (TLIF). Methods: A retrospective and case control study with six patients using PEEK cages and four patients using ZTC was conducted. All patients underwent TLIF and had a 3-month follow-up. The Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) were selected to assess the pain of low back and neurological status. The intervertebral disc height (DH) and segmental angle (SA) were also measured to estimate the radiological changes. At the 3-month follow-up, the fusion and subsidence rates were evaluated. Results: There was no significant difference between the two groups regarding the ODI and VAS scores. At the 3-month follow-up, the subsidence rates were 42% and 0% for the PK and ZTC groups, respectively; the bony fusion rates were 67% and 100% for the PK and ZTC groups, respectively. Conclusion: The study has indicated that both PEEK and [Formula: see text]-shaped titanium cages can be effective options used to treat degenerative disc disease (DDD). Moreover, the higher fusion and lower subsidence rates have revealed that [Formula: see text]-shaped titanium cages may be a better choice compared to PEEK cages for lumbar reconstruction after TLIF.

Radiographic outcomes of transosseous intradiscal screw fixation in lumbar reconstruction—Imaging results of an experience with an alternative in fixation of the unexpectedly osteopenic spine

ObjectiveTo present the results of a new alternative in the technique lumbar pedicle screw reconstruction in osteopenic bone. Pedicle screw fixation is compromised in osteopenic bone and adjunct fixation commonly requires incremental technology that can increase cost and risk, and which may not commonly be available. Readily available low cost techniques are desirable. Patients and MethodsThis is a retrospective review of a prospectively accumulated case series of all patients presenting to the senior author’s (DAB) practice for elective lumbar reconstruction at a tertiary spine referral center. All consecutive patients treated by the senior author 2002–2012 who were unexpectedly found to be severely osteopenic at surgery are reported. ResultsIn seventy-four cases with imaging and clinical information available at an average of five years after surgery there was no screw lucency or accelerated disc degeneration observed despite these screws purposefully projecting into the suprajacent disc space within the limits of the construct. No patient had presented for instrumentation-related revision surgery of any sort. ConclusionTransosseous intradiscal screw fixation is a potentially viable alternative in surgical stabilization of the unexpectedly osteopenic lumbar spine.

Clinical outcomes of two types of cages used in transforaminal lumbar interbody fusion for the treatment of degenerative lumbar diseases: n-HA/PA66 cages versus PEEK cages.

This study reports the clinical effects of nano-hydroxyapatite/polyamide66 cages (n-HA/PA66 cages) and compares the clinical outcomes between n-HA/PA66 and polyetheretherketone cages (PEEK cages) for application in transforaminal lumbar interbody fusion (TLIF). A retrospective and case–control study involving 124 patients using n-HA/PA66 cages and 142 patients using PEEK cages was conducted. All patients underwent TLIF and had an average of 2-years of follow-up. The Oswestry Disability Index and Visual Analog Scale were selected to assess the pain of low back and leg, as well as neurological status. The intervertebral space height and segmental angle were also measured to estimate the radiological changes. At the 1-year and final follow-ups, the fusion and subsidence rates were evaluated. There was no significant difference between the two groups regarding clinical and radiological results. At the final follow-up, the bony fusion rate was 92.45 and 91.57 % for the n-HA/PA66 and PEEK groups, respectively, and the subsidence rate was 7.55 and 8.99 %, respectively. The study indicated that both n-HA/PA66 and PEEK cages could promote effective clinical and radiographic outcomes when used to treat degenerative lumbar diseases. The high fusion and low subsidence rates revealed that n-HA/PA66 cages could be an alternative ideal choice as the same to PEEK cages for lumbar reconstruction after TLIF.

Lumbar BCC removal and reconstruction with a perforator plus flap

The lower back still remains a challenging area for a reconstructive surgeon, especially when it comes to a big defect. A 78-year-old man presented with a neglected basal cell carcinoma (BCC). He underwent excision of the lesion and reconstruction of the 18 × 10-cm defect with a lumbar perforator plus flap. His operation and final outcome are presented, and the possible options for reconstruction are discussed. The advantages of the rotational design, the axial blood supply, and the skin island preservation are reported, giving the lumbar perforator plus flap a definite role in a difficult area such as the lower back.

Application of the pedicled m. latissimus dorsi flap for trunk reconstructions

PURPOSE: M. latissimus dorsi flap is one of the most commonly used pedicled flaps in plastic surgery. It can be based either on the dominant thoracodorsal vessels, or, as a reverse flap, on its secondary segmental pedicles. The purpose of this paper is to evaluate our experience with pedicled flaps from m. latissimus dorsi for trunk reconstructions. MATERIAL AND METHODS: In the present study, we applied eight flaps on 7 patients: four flaps for breast reconstruction, one flap for postmastectomy radiation wound treatment, one flap to cover a defect on the anterior thoracic wall caused by toxic skin necrosis, one flap to correct axillary skin contracture after deep burn injury, and one for lumbar reconstruction after malignant melanoma radical excision. RESULTS: In the present paper, two cases with application of this flap were reported to illustrate the stages of the surgical technique. All the flaps were vital and adapted normally. Narrow partial skin necrosis and donor scar depression were observed in the largest skin-muscle flap only. CONCLUSION: M. latissimus dorsi pedicled flaps are reliable source for trunk reconstructions. They may transfer abundant plastic material to compensate tissue deficit of different etiology. The risk of complications is insignificant, whereas the patients' quality of life is considerably improved. Scripta Scientifica Medica 2013; 45(2): 86-90.

Acute Spinal Subdural Hematoma Subsequent To Posterior Lumbar Fusion

Objective: To report a rare case of post-operative cauda equina syndrome subsequent to lumbar decompression and reconstruction, and review the relevant anatomical causes of spinal subdural hematoma. We present a case report of an acute spinal subdural hematoma, following surgical decompression and fusion. The etiology of spinal subdural hematoma after spinal surgery is controversial. We propose that violation of the dural-arachnoid interface is a likely mechanism of this complication. Summary of background data: Spinal subdural hematoma (SSDH) is a very rare postoperative complication of surgical decompression. We report the presentation of acute SSDH presenting with acute cauda equine, following lumbar decompression and reconstruction in a patient lacking risk factors for this rare complication. Methods: A 72 year old man with a history of prior L2-5 laminectomy presented with persistent lower back and left lower extremity radicular pain, due to lumbar spondylosis with foraminal stenosis due to synovial cyst, and lumbar disc herniation. He underwent a revision L2-5 laminectomy with foramintomies, L3-4 synovial cyst resection, and L3-4 posterolateral instrumented fusion. Small incidental duratomy without arachnoid fenestration and without cerebrospinal fluid extravasation, was noted and repaired intraoperatively. On post-operative day four, the patient presented with acute cauda equina syndrome, found to be associated with an acute dorsal lumbar subdural hematoma. Results: After emergent evacuation of the hematoma, patient had immediate resolution of symptoms, and continued to demonstrate dramatic improvement after 1-year follow-up. Conclusions: Despite its low incidence, SSDH should be considered in the setting of acute cauda equina syndrome, following surgical decompression. Prompt evacuation of hematoma is associated with good prognosis. The etiology of SSDH post spinal surgery is controversial. Violation of the dural-arachnoid interface and destruction of local neurothelial cells is the suspected etiology of this very rare complication.

CHALLENGING DEGENERATIVE LUMBAR SCOLIOSIS WITH SEGMENTAL CORRECTIVE FUSION SURGERY

Changes in the curvature have not been reported in degenerative lumbar scoliosis (DLS) when the correction surgery was performed. The purpose of our study was to clarify the influence of the correction surgery of DLS. Twenty-one patients underwent corrective lumbar reconstruction surgery (1998–2003) only at the neurologically affected levels. The spinal curvature was retrospectively evaluated in these 21 patients with DLS using Cobb's methods. The mean preoperative Cobb's angle was 17.7° while the mean postoperative Cobb's angle was 6.1° (p &lt; 0.0001) at 1 month after the surgery and 9.0° at the final follow-up. The correction rate was 65.2% at 1 month after the surgery and 50.2% at the final follow-up. Cobb's angle increased by 2.9°/43.4 months (mean, 0.80°/year) in these procedure. The surgical goals of DLS are the relief of neurological disorders and the cessation of the deterioration of spinal alignment. Strategies for DLS may include complete decompression, or correction of the spinal alignment in elderly patients with poor bone quality. Decompression and correction in the PLIF procedure only at neurologically affected levels may be one of the surgical procedures to challenge DLS.

Biomechanical study on the effect of five different lumbar reconstruction techniques on adjacent-level intradiscal pressure and lamina strain

The objectives of this study were to compare the biomechanical effects of five lumbar reconstruction models on the adjacent segment and to analyze the effects of three factors: construct stiffness, sagittal alignment, and the number of fused segments. Nondestructive flexion-extension tests were performed by applying pure moments to 10 calf spinal (L3-S1) specimens. One-segment (L5-6) or two-segment (L5-S1) posterior fusion methods were simulated: 1) one-segment posterolateral fusion (PLF); 2) one-segment PLF with interbody fusion cages (one-segment PLIF/PLF); 3) two-segment PLF; 4) two-segment PLIF/PLF; and 5) two-segment PLF in kyphosis (two-segment kyphotic PLF). The range of motion (ROM) of the reconstructed segments, intradiscal pressure (IDP), and lamina strain in the upper (L4-5) adjacent segment were analyzed. The ROM was significantly decreased in the PLIF/PLF models compared with that in the PLF alone models after both the one- and two-segment fusions. If the number of fused segments was increased, the pressure and strains were also increased in specimens subjected to the PLIF/PLF procedure, more so than the PLF-alone procedure. In the one-segment PLIF/PLF model the authors observed a reduced IDP and lamina strain compared with those in the kyphotic two-segment PLF model despite the latter's higher levels of initial stiffness. If the number of fused levels can be reduced by using PLIF to correct local kyphosis, then this procedure may be valuable for reducing adjacent-segment degenerative changes.

P67. Ten-year follow up laparoscopic lumbar reconstruction and decompression

P67. Ten-year follow up laparoscopic lumbar reconstruction and decompression

Types of Spinal Instability That Require Interbody Support in Posterior Lumbar Reconstruction

Pedicle screw fixation alone for sequential spinal instabilities was biomechanically compared with pedicle screw fixation using interbody cages. To evaluate biomechanical effects of interbody cages on construct stiffness, pedicle-screw strain, and the adjacent level in posterior lumbar reconstruction using pedicle screw fixation. It remains undetermined what types of spinal instability require interbody support in posterior lumbar reconstruction. For this study, 10 calf spines (L3-L6) were used. Sequential destabilization was performed at L4-L5 followed by posterior reconstruction using pedicle screw fixation (PS) and interbody cages as follows: intact + PS (I-PS), medial facetectomy + PS (MF-PS), total facetectomy + PS (TF-PS), partial discectomy + PS (D-PS), and D-PS + interbody cages (PLIF). Biomechanical testing was performed under flexion and extension loading modes. Construct stiffness (L4-L5), rod-screw bending strain, and range of motion (ROM) at the upper adjacent level (L3-L4) were analyzed. In terms of construct stiffness (L4-L5), all the reconstructions except D-PS demonstrated higher construct stiffness than the intact spine (P < 0.05). The PLIF showed the highest stiffness among all the reconstructions (P < 0.05). In terms of ROM (L3-L4), all the reconstructions increased the ROM, as compared with the intact state (P < 0.05). Importantly, PLIF showed significantly greater ROM than all the other reconstructions except I-PS (P < 0.05). In terms of rod-screw strain, the D-PS resulted in higher strain than the other groups (P < 0.05). The PLIF presented less strain than the other reconstructions (P < 0.05). For spinal instability with preserved anterior load sharing, pedicle screw fixation alone is biomechanically adequate, and interbody cages should not be used because they further increase segmental motion at the adjacent segment. However, PS alone provides insufficient stability and high implant strain in case of damaged anterior column. In such cases, additional interbody cages significantly increase construct stiffness and decrease hardware strain. However, they increase ROM at the adjacent segment as well.

Le recalibrage dans le traitement du canal lombaire �troit

Lumbar stenosis has been well discussed recently, especially at the 64th French Orthopaedic Society (SOFCOT: July 1989). The results of different surgical treatments were considered as good, but the indications for surgical treatment were not clear cut. Laminectomy is not the only treatment of spinal stenosis. Laminectomy is an approach with its own rate of complications (dural tear, fibrosis, instability... ).Eight years ago, J. Sénégas described what he called the "recalibrage" (enlargement). His feeling was that, in the spinal canal, we can find two different AP diameters. The first one is a fixed constitutional AP diameter (FCAPD) at the cephalic part of the lamina. The second one is a mobile constitutional AP diameter (MCAPD) marked by the disc and the ligamentum flavum. This diameter is maximal in flexion, minimal in extension. The nerve root proceeds through the lateral part of the canal: first above, between the disc and the superior articular process, then below, in the lateral recess bordered by the pedicle, the vertebral body and the posterior articulation. With the degenerative change the disc space becomes shorter, the superior articular process is worn out with osteophytes. These degenerative events are complicated by inter vertebral instability increasing the stenosis. The idea of the "recalibrage" is to remove only the upper part of the lamina with the ligamentum flavum and to cut the hypertrophied anterior part of the articular process from inside. If needed the disc and other osteophytes are removed. The surgery is finished with a ligamentoplasty reducing the flexion and preventing the extension by a posterior wedge.Our experience in spine surgery especially in scoliosis surgery, showed us that it was possible to cure a radicular compression without opening the canal. The compression is then lifted by the 3D reduction and restoration of an anatomy as normal as possible. Lumbar stenosis is the consequence of a degenerative process. Indeed, hip flexion, obesity or quite simply overuse, involve an increase in the lumbar lordosis. The posterior articulations are worn out and the disc gets damaged by shear forces. The disc space becomes shorter with a bulging disc, and the inferior articular process of the superior vertebra goes down. This is responsible of a loss of lordosis. For restoring the sagittal balance the patient needs more extension of the spine. Above and below the considered level the degenerative disease carries on extending to the whole spine. At the level considered, because of local extension, the inferior facet moves forward, the disc bulges, the ligamentum flavum is shortened and the stenosis is increased. This situation is improved by local kyphosis: the inferior facet moves backward, the disc and the ligamentum flavum are stretched with a quite normal posterior disc height and most often there is no more stenosis. Myelograms show this very well with a quite normal appearance lying, clear compression standing, worse in extension and improved, indeed disappeared in flexion. CT scan and MRI don't show that because they are done lying. The expression of the clinical situation is the same, mute lying and maximum standing with restriction of walking. For us lumbar stenosis is operated with lumbar reconstruction without opening the canal. The patient is in moderate kyphosis on the operating table. Pedicle screws rotated to match a bent rod allow reduction of the spine. The posterior disc height is respected and not distracted, and the anterior part of the disc is stretched in lordosis. The inferior facet is cut for the arthrodesis and no longer compresses the dura. The canal is well enlarged and the lumbar segment in lordosis is the best protection of the adjacent levels at follow-up. This behaviour responds to the same analysis as the ≪recalibrage≫ (enlargement). The mobile segment is damaged by the degenerative disease, the stenosis is a consequence of this damage. It's logical to treat the instability and to restore the normal static anatomy; thus bone resection is not necessary. At the present time all the lumbar stenoses with reduction in flexion are instrumented with spinal reduction and arthrodesis without opening the canal. The laminoarthrectomy and the enlargement are done when there is a fixed arthrosis which is rare in our practice and found in an older population. The follow-up shows a loss of reduction in some cases after reduction-instrumentation-arthrodesis and poses the question of an interbody fusion. We don't open the canal only for fusion (PLIF) if this is not necessary for the treatment of the stenosis. We think that, in such a situation, the future is ALIF with endoscopical approach. The problem is to determine which disc demanding this anterior fusion, is able to regenerate or not.