Perioperative surgical complications of transforaminal lumbar interbody fusion: a single-center experience

Spinal Anesthesia Reduces Perioperative Polypharmacy and Opioid Burden in Patients Over 65 Who Undergo Transforaminal Lumbar Interbody Fusion

BACKGROUND

Polypharmacy and opioid administration are thought to increase the risk of postoperative cognitive dysfunction and delirium in elderly patients. Spinal anesthesia (SA) holds potential to reduce perioperative polypharmacy in spine surgery. As more geriatric patients undergo spine surgery, understanding how SA can reduce polypharmacy and opioid administration is warranted. We aim to compare the perioperative polypharmacy and dose of administered opioids in patients ≥65 years who undergo transforaminal lumbar interbody fusion (TLIF) under SA versus general anesthesia (GA).

METHODS

A retrospective analysis of 200 patients receiving a single-surgeon TLIF procedure at a single academic center (2014-2021) was performed. Patients underwent the procedure with SA (n = 120) or GA (n = 80). Demographic, procedural, and medication data were extracted from the medical record. Opioid consumption was quantified as morphine milligram equivalents (MME). Statistical analyses included χ2 or Student's t-test.

RESULTS

Patients receiving SA were administered 7.45 medications on average versus 12.7 for GA patients (P < 0.001). Average perioperative opioid consumption was 5.17 MME and 20.2 MME in SA and GA patients, respectively (P < 0.001). The number of patients receiving antiemetics and opioids remained comparable postoperatively, with a mean of 32.2 MME in the GA group versus 27.5 MME in the SA group (P = 0.14). Antiemetics were administered less often as a prophylactic in the SA group (32%) versus 86% in the GA group (P < 0.001).

CONCLUSIONS

SA reduces perioperative polypharmacy in patients ≥65 years undergoing TLIF procedures. Further research is necessary to determine if this reduction correlates to a decrease the incidence of postoperative cognitive dysfunction and delirium.

Articular arthrodesis with the facet wedge technique for the treatment of unstable lumbar degenerative disease and associated conditions: A retrospective study of 96 patients

Background

Lumbar articular fusion with the facet wedge (FW) technique is gaining increasing interest among surgeons for the treatment of vertebral instability due to its limited invasiveness and ease of use. Studies on cadavers have reported biomechanical properties similar to pedicle screws. Yet, the evidence supporting their use is still limited and moreover focused only on spinal degenerative disease.

Methods

96 cases of lumbar articular fusion with the FW techniques performed at 3 different centers between 2014 and 2022 were retrospectively analyzed based on the specific surgical indications: 1) degenerative spondylolisthesis/unstable lumbar stenosis; 2) synovial cysts; 3) adjacent segment disease (ASD). Medical records were reviewed to identify rates of complications and measures of functional outcome (ODI, low back pain VAS and modified Macnab scale) were collected both at baseline and at the follow-up visits. Wilcoxon signed-rank test was adopted to test for significant functional improvements.

Results

Significative clinical improvements were observed from baseline to follow-up regarding ODI and VAS scores. Overall rate of moderate and severe complications (according to Landriel-Ibañez scale) was 7.9%. Only 3.4% of patients with degenerative disease developed ASD requiring reoperations. Only one case of radicular deficit and one of device mobilization were reported. 2/4 cases of synovial cysts treated with unilateral fusions developed contralateral complications. 9 out of 16 (56.25%) patients who underwent long-term postoperative CT scans presented adequate degree of articular fusion.

Conclusion

FW technique is easy, safe, and effective. Its low rate of complications justifies its use for cases of mild lumbar instability.

Lateral lumbar interbody fusion at L4-L5 has a low rate of complications in appropriately selected patients when using a standardized surgical technique

Aims

The aim of this study was to reassess the rate of neurological, psoas-related, and abdominal complications associated with L4-L5 lateral lumbar interbody fusion (LLIF) undertaken using a standardized preoperative assessment and surgical technique.

Methods

This was a multicentre retrospective study involving consecutively enrolled patients who underwent L4-L5 LLIF by seven surgeons at seven institutions in three countries over a five-year period. The demographic details of the patients and the details of the surgery, reoperations and complications, including femoral and non-femoral neuropraxia, thigh pain, weakness of hip flexion, and abdominal complications, were analyzed. Neurological and psoas-related complications attributed to LLIF or posterior instrumentation and persistent symptoms were recorded at one year postoperatively.

Results

A total of 517 patients were included in the study. Their mean age was 65.0 years (SD 10.3) and their mean BMI was 29.2 kg/m2 (SD 5.5). A mean of 1.2 levels (SD 0.6) were fused with LLIF, and a mean of 1.6 (SD 0.9) posterior levels were fused. Femoral neuropraxia occurred in six patients (1.2%), of which four (0.8%) were LLIF-related and two (0.4%) had persistent symptoms one year postoperatively. Non-femoral neuropraxia occurred in nine patients (1.8%), one (0.2%) was LLIF-related and five (1.0%) were persistent at one year. All LLIF-related neuropraxias resolved by one year. A total of 32 patients (6.2%) had thigh pain, 31 (6.0%) were LLIF-related and three (0.6%) were persistent at one year. Weakness of hip flexion occurred in 14 patients (2.7%), of which eight (1.6%) were LLIF-related and three (0.6%) were persistent at one year. No patients had bowel injury, three (0.6%) had an intraoperative vascular injury (not LLIF-related), and five (1.0%) had ileus. Reoperations occurred in five patients (1.0%) within 30 days, 37 (7.2%) within 90 days, and 41 (7.9%) within one year postoperatively.

Conclusion

LLIF involving the L4-L5 disc level has a low rate of persistent neurological, psoas-related, and abdominal complications in patients with the appropriate indications and using a standardized surgical technique.

Application of the cortical bone trajectory technique in posterior lumbar fixation

The cortical bone trajectory (CBT) is a novel technique in lumbar fixation and fusion. The unique caudocephalad and medial-lateral screw trajectories endow it with excellent screw purchase for vertebral fixation via a minimally invasive method. The combined use of CBT screws with transforaminal or posterior lumbar interbody fusion can treat a variety of lumbar diseases, including spondylolisthesis or stenosis, and can also be used as a remedy for revision surgery when the pedicle screw fails. CBT has obvious advantages in terms of surgical trauma, postoperative recovery, prevention and treatment of adjacent vertebral disease, and the surgical treatment of obese and osteoporosis patients. However, the concept of CBT internal fixation technology appeared relatively recently; consequently, there are few relevant clinical studies, and the long-term clinical efficacy and related complications have not been reported. Therefore, large sample and prospective studies are needed to further reveal the long-term complications and fusion rate. As a supplement to the traditional pedicle trajectory fixation technique, the CBT technique is a good choice for the treatment of lumbar diseases with accurate screw placement and strict indications and is thus deserving of clinical recommendation.

The Role of Diskectomy in Reducing Infectious Complications after Surgery for Lumbar Spondylodiscitis

BACKGROUND

 Surgery for pyogenic Spondylodiscitis as an adjunct to antibiotic therapy is an established treatment. However, the technique and extent of surgical debridement remains a matter of debate. Some propagate diskectomy in all cases. Others maintain that stand-alone instrumentation is sufficient.

METHODS

 We reviewed charts of patients who underwent instrumentation for pyogenic Spondylodiscitis with a minimum follow-up of 1 year. Patients were stratified according to whether they underwent diskectomy plus instrumentation or posterior instrumentation alone. Outcome measures included the need for surgical revision due to recurrent epidural intraspinal infection, wound revision, and construct failure.

RESULTS

 In all, 257 patients who underwent surgery for pyogenic Spondylodiscitis were identified. Diskectomy and interbody procedure (group A) was performed in 102 patients, while 155 patients underwent instrumentation surgery for Spondylodiscitis without intradiskal debridement (group B). The mean age was 67 ± 12 years, and 102 patients (39.7%) were females. No significant differences were found in the need for epidural abscess recurrence therapy (group A [2.0%] and 5 cases in group B [3%; p = 0.83]) and construct failure (p = 0.575). The need for wound revisions showed a tendency toward higher rates in the posterior instrumentation-only group, which failed to reach significance (p = 0.078).

CONCLUSIONS

 Overall, intraspinal relapse of surgically treated pyogenic diskitis was low in our retrospective series. The choice of surgical technique was not associated with a significant difference. However, a somewhat higher rate of wound infections requiring revision in the group where no diskectomy was performed has to be weighed against a longer duration of surgery in an already ill patient population.

Application of Oblique Lateral Interbody Fusion Combined with Bridge-Locking Cage in Adjacent Segment Disease After Lumbar Fusion

OBJECTIVE

Adjacent segment disease (ASD) is considered any abnormal process that develops in the mobile segment next to spinal fusion, accompanied by related symptoms. To evaluate the efficacy and complications of oblique lateral interbody fusion (OLIF) combined with bridge-locking fusion on ASD after lumbar fusion.

METHODS

A total of 35 ASD patients who required re-operation after lumbar fusion in our hospital from March 2014 to March 2020 were retrospectively analyzed, among which 13 cases (seven males and six females; 62.3 ± 11.3 years old) received the treatment of OLIF + bridge-locking cage internal fixation (OLIF group), and 22 cases (14 males and eight females; 52.3 ± 17.8 years old) received the treatment of transforaminal lumbar interbody fusion (TLIF) + pedicle screw fixation (TLIF group). The comparison of the operation time, intraoperative blood loss, postoperative drainage volume, and length of hospital stay between the two groups of patients was performed using the t-test. The comparison of Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) at different time points before and after the operation was performed using analysis of variance for repeated measurement data. The fusion rate and postoperative complications of the two groups of patients were also evaluated.

RESULTS

The operation time of patients in the OLIF group (55.4 ± 12.4 min) was significantly shorter than that of patients in the TLIF group (94.3 ± 22.9 min) (P < 0.05), the length of stay of patients in the OLIF group (7.4 ± 2.3 day) was significantly shorter than that of patients in the TLIF group (12.4 ± 3.2 day) (P < 0.05); the intraoperative blood loss (62.2 ± 30.1 mL) and postoperative drainage (47.3 ± 22.4 mL) of patients in the OLIF group were significantly less than those of patients in the TLIF group with intraoperative blood loss (363.4 ± 120.2 mL) and postoperative drainage (285.5 ± 57.8 mL) (all Ps < 0.05). Besides, the VAS and ODI scores of the two groups of patients were improved 3 months after the operation and at the last follow-up (all Ps < 0.05). Three patients in the OLIF group developed complications such as hip flexion weakness and fusion cage sink, with an incidence of 23.1%. Three patients in the TLIF group developed complications including wound infection and intraoperative nerve injury, with an incidence of 22.7%.

CONCLUSION

The combination of OLIF and bridge-locking cage may be a safe and effective therapy for ASD patients after lumbar fusion operation.

Adult Isthmic Spondylolisthesis: A Radiographic and Outcomes Analysis Comparing Circumferential Fusions Versus TLIF Procedures

STUDY DESIGN

This was a retrospective cohort study.

OBJECTIVE

The objective of this study was to compare radiographic and patient-reported outcome measures (PROMs) between circumferential fusions and transforaminal lumbar interbody fusion (TLIF) for adult isthmic spondylolisthesis (IS).

SUMMARY OF BACKGROUND DATA

Definitive management of adult IS typically requires decompression and fusion. Multiple fusion techniques have been described, but literature is sparse in identifying the optimal technique.

METHODS

Patients with IS undergoing single-level or 2-level circumferential fusion or TLIF with a minimum 1-year follow-up were included. Patient demographics, surgical characteristics, and PROMs were extracted from patients' electronic medical records. Descriptive statistics and multivariate regression analysis compared outcomes with significance set at P -value <0.05.

RESULTS

A total of 78 circumferential fusions (48 open decompression and fusions and 30 circumferential fusions utilizing posterior percutaneous instrumentation) and 50 TLIF procedures were included. Length of stay was significantly longer when comparing circumferential procedures (3.56±0.96 d) versus TLIFs (2.88±1.14 d) ( P =0.002). The circumferential fusion group resulted in greater postoperative improvement in segmental lordosis [anterior/posterior (A/P): 6.45, TLIF: -1.99, P <0.001], posterior disk height (A/P: 12.6 mm, TLIF: 8.9 mm, P <0.001), and ∆disk height (A/P: 7.7 mm, TLIF: 3.6 mm, P <0.001). Both groups significantly improved in all PROMs ( P <0.001). While the circumferential fusion group had a significantly higher rate of perioperative surgical complications (12.82% vs. 2.00%, P =0.049), there was no difference in the rate of 30-day readmissions ( P =0.520) or revision surgeries between techniques ( P =0.057).

CONCLUSIONS

Circumferential fusions are associated with improvements in radiographic outcomes compared with TLIFs, but this is at the expense of longer hospital length of stay and increased risk for perioperative complications. The surgical technique did not result in superior postoperative PROMs or differences in readmissions or revisions.

Ten-Year Outcomes of Minimally Invasive Versus Open Transforaminal Lumbar Interbody Fusion in Patients With Single-Level Lumbar Spondylolisthesis

STUDY DESIGN

A retrospective observational study.

OBJECTIVE

This study investigated the clinical and radiological results of minimally invasive (MI) versus open transforaminal lumbar interbody fusion (TLIF) in patients with single-level lumbar spondylolisthesis over a 10-year period.

SUMMARY OF BACKGROUND DATA

Few studies have compared 10-year follow-up outcomes between MI-TLIF and open TLIF.

METHODS

We retrospectively collected the outcome data of patients with single-level lumbar spondylolisthesis who underwent TLIF procedures using an MI (n = 108) or open (n = 53) approach. Fifty-two (48%) and 31 (58%) patients in the MI-TLIF and open TLIF groups, respectively, completed the 10-year follow-up. A primary clinical outcome included the Oswestry Disability Index (ODI) as well as visual analog scale (VAS) scores for back and leg pain at baseline and at 2, 5, and 10 years postoperatively. The radiographic fusion rate and incidence of secondary surgery due to adjacent segment disease were assessed at 2, 5, and 10 years postoperatively.

RESULTS

Intraoperative blood loss and length of hospitalization were significantly lower in the MI-TLIF group than in the open TLIF group. At 2 years postoperatively, the ODI and VAS scores for back and leg pain were significantly lower in the MI-TLIF group than in the open TLIF group. No significant differences were found in VAS scores for back and leg pain or ODI scores between the two groups at 10 years postoperatively. Radiographic fusion rates and prevalence of secondary surgery for adjacent segment disease were not significantly different between the groups at 10 years postoperatively.

CONCLUSION

Efficacy of MI-TLIF for patients with single-level lumbar spondylolisthesis is comparable to that of open TLIF over 10-years. However, MI-TLIF may have superior perioperative recovery and 2-year postoperative functional outcomes than open TLIF.Level of Evidence: 3.

Traumatic Vertebral Fracture in a Patient With Transforaminal Lumbar Interbody Fusion: A Rare Complication

Transforaminal lumbar interbody fusion (TLIF) offers the potential benefits of anterior and posterior column decompression and fusion. Pseudarthrosis and infection are among the most common perioperative complications. Vertebral fracture after TLIF is a rare and unusual complication. A 74-year-old female underwent L3-5 TLIF for lumbar spondylolisthesis that caused back pain and neurogenic claudication. She recovered well after surgery. However, she subsequently experienced progressive back pain and recurrent claudication after a fall. Elongated anterior-posterior length of the L5 body with progressive L5-S1 listhesis was observed in the serial radiographic follow-ups. The CT scan revealed complicated fracture lines crossing the L5 body. Further extended fixation was performed for decompression and reconstruction of the lumbosacral alignment. Although vertebral fracture after TLIF is a rare complication, a high index of suspicion is the key to early diagnosis, preferably with CT scans, for patients with traumatic accidents after TLIF surgery.

Perioperative Complications of Minimally Invasive Transforaminal Lumbar Interbody Fusion (MI-TLIF): 10 Years of Experience With MI-TLIF

STUDY DESIGN

A prospective study.

OBJECTIVES

We present a largest study until date performed over a period of 10 years assessing the perioperative complications. The primary aim of this study was to review the incidence of perioperative complications of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) in single-level lumbar degenerative diseases.

METHODS

A prospective study performed over a period of 10 years involving 560 patients who underwent single-level lumbar MI-TLIF. Perioperative clinical and radiological parameters, postoperative complications, and satisfactory outcomes in the form of Wang's criteria were evaluated. All patients were scrutinized into 5 different categories based on the descriptive classification for perioperative complications suggested by the authors.

RESULTS

The mean age was 61.8 ± 12.7 years and male to female ratio was 0.8:1. The overall incidence of the perioperative complication was 25.5%. In all, 19.64% patients developed single complication, 4.64% patients were with 2 complications, and 1.25% patients developed 3 complications from the described categories. A total of 16.78% patients developed early (<6 months postsurgery) and 8.75% patients developed late (>6 months postsurgery) complications.

CONCLUSION

This study showed 25.5% incidence of perioperative complications in MI-TLIF for degenerative lumbar disease over a period of 10 years with a higher incidence rate during the initial 3 years of practice. The described classification for perioperative complications is helpful to record, to evaluate and to understand the etiology based on its duration of occurrence in the perioperative period. MI-TLIF is an effective procedure with substantial clinical benefits in the form of excellent to good clinical-radiological outcomes.

Implant Preservation versus Implant Replacement in Revision Surgery for Adjacent Segment Disease After Thoracolumbar Instrumentation: A Retrospective Study of 43 Patients

OBJECTIVE

To evaluate the mechanical properties of a new connector rod aiming to preserve implants in revision surgery (RS) for adjacent segment disease, a problematic complication of instrumented spinal fusion, and to assess its clinical applicability.

METHODS

The mechanical properties of the connector-rod construct (implant preservation) and traditional rod construct (implant replacement) were evaluated and compared. Forty-three patients underwent RS for adjacent segment disease in the thoracolumbar spine with implant preservation or replacement, and radiological and clinical outcomes were assessed.

RESULTS

Mechanical properties in group A were comparable to those in group B. Total mean time from prior surgery to RS was 6.86 ± 1.08 years. Surgical time and blood loss values of group A were 40.14% and 29.29% statistically significantly smaller than values of group B. In group B, 12% (3/25) of patients developed surgical site infections. In both groups, the visual analog scale leg score decreased significantly after RS. Early postoperative (at 1-month and 3-month follow-up) Oswestry Disability Index and visual analog scale back scores of group A were significantly lower than those of group B; the difference in the visual analog scale back score between groups was significant until the 6-month follow-up. No implant failures occurred, and spinal fusion was achieved in all cases.

CONCLUSIONS

The connector rod is considered safe and can reduce the surgical time, blood loss, risk of complications, and medical costs. Better early postoperative clinical outcomes can be achieved with the rod owing to less surgical trauma.

The anterior and traverse cage can provide optimal biomechanical performance for both traditional and percutaneous endoscopic transforaminal lumbar interbody fusion

BACKGROUND

Transforaminal lumbar interbody fusion (TLIF) is a well-established surgical treatment for patients with lumbar degenerative disc disease; however, the optimal position for the interbody fusion cage in TLIF procedures for reducing cage-related complications remains uncertain. The present study aims to compare the biomechanical effects between different cage positions in TLIF and percutaneous endoscopic-TLIF (PE-TLIF).

METHOD

An intact finite element model of L3-L5 from computed tomography images of a 25-year-old healthy male without any lumbar disease was reconstructed and validated. TLIF and PE-TLIF were performed on L4-L5 with bilateral pedicle screws fixation. Two surgical finite element models were subjected to loads with six degrees of freedom. The range of motion (ROM) and von Mises stress of the implantations and endplates were measured for the anterior, middle, and posterior district and the traverse or oblique direction of the cage respectively.

RESULTS

As the cage was implanted forward, the ROMs in the fused L4-L5 segments and the von Mises stress of the cage and endplates decreased while the von Mises stress of the screws increased; this was also shown in the traverse cage when compared with the oblique cage (A-90-compared with A-45- had a 31.3%, 1.7%, 12.6%, and 5.7% decrease in FL, EX, LB and AR). The ROMs (TLIF A-45 increase of 80.8%, 23.8%, and 12.2% in FL, EX, and LB when compared with PE-TLIF), cage stress, and endplate stress of PE-TLIF were lower than those of TLIF.

CONCLUSIONS

Considering the ROM of the fusion segments, implanting the cage in the anterior district in the traverse direction can effectively enhance the fusion segment stiffness, thus contributing to the stability of the lumbar spine after fusion. It can also cause less cage stress and endplate stress, which indicates its beneficial effect in avoiding cage injury or subsidence. However, the higher stress of the pedicle screws and rods indicates higher failure risk. PE-TLIF had better biomechanical performance than TLIF. Therefore, it is recommended that the surgeon implant the cage in the anterior district of the L5 vertebra's upper endplate in the traverse direction using the PE-TLIF technique.

Comparison of robot-assisted and freehand pedicle screw placement for lumbar revision surgery

BACKGROUND

The accuracy of robot-assisted pedicle screw implantation is a safe and effective method in lumbar surgery, but it still remains controversial in lumbar revision surgery. This study evaluated the clinical safety and accuracy of robot-assisted versus freehand pedicle screw implantation in lumbar revision surgery.

METHODS

This was a retrospective study. From January 2018 to December 2019, 81 patients underwent posterior lumbar revision surgery in our hospital. Among them, 39 patients underwent revision surgery performed with robot-assisted pedicle screw implantation (Renaissance robotic system), whereas the remaining 42 patients underwent traditional freehand pedicle screw implantation. All patients underwent magnetic resonance imaging (MRI), computed tomography (CT), and X-ray before revision surgery. The sex, age, body mass index, bone mineral density, operative time, blood loss, operative segments, intra-operative fluoroscopy time, and complications were compared between the two groups. The accuracy of pedicle screw implantation was measured on CT scans based on Gertzbein Robbins grading, and the invasion of superior level facet joint was evaluated by Babu's method.

RESULTS

There was no statistical difference about the baseline between the two groups (P > 0.05). Although there were no significant differences in operative time and complications between the two groups (P > 0.05), the robot-assisted group had significantly less intra-operative blood loss and shorter intra-operative fluoroscopy times than the freehand group (P < 0.05). In the robot-assisted group, a total of 267 screws were inserted, which were marked as grade A in 250, grade B in 13, grade C in four, and no grade D or E in any screw. In terms of invasion of superior level facet joint, a total of 78 screws were inserted in the robot-assisted group, which were marked as grade 0 in 73, grade 1 in four, grade 2 in one, and grade 3 in zero. By comparison, 288 screws were placed in total in the freehand group, which were rated as grade A in 251, grade B in 28, grade C in eight, grade D in one, and no grade E in any screw. A total of 82 superior level facet joint screws were inserted in freehand group, which were marked as grade 0 in 62, grade one in 18, grade 2 in two, and grade 3 in zero. The robot-assisted technique was statistically superior to the freehand method in the accuracy of screw placement (P < 0.05).

CONCLUSION

Compared with freehand screw implantation, in lumbar revision surgery, the Renaissance robot had higher accuracy and safety of pedicle screw implantation, fewer superior level facet joint violations, and less intra-operative blood loss and intra-operative fluoroscopy time.

Lateral lumbar interbody fusion in revision surgery for restenosis after posterior decompression

OBJECTIVE

The purpose of this study was to compare the clinical results of revision interbody fusion surgery between lateral lumbar interbody fusion (LLIF) and posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF) with propensity score (PS) adjustments and to investigate the efficacy of indirect decompression with LLIF in previously decompressed segments on the basis of radiological assessment.

METHODS

A retrospective study of patients who underwent revision surgery for recurrence of neurological symptoms after posterior decompression surgery was performed. Postoperative complications and operative factors were evaluated and compared between LLIF and PLIF/TLIF. Moreover, postoperative improvement in cross-sectional areas (CSAs) in the spinal canal and intervertebral foramen was evaluated in LLIF cases.

RESULTS

A total of 56 patients (21 and 35 cases of LLIF and PLIF/TLIF, respectively) were included. In the univariate analysis, the LLIF group had significantly more endplate injuries (p = 0.03) and neurological deficits (p = 0.042), whereas the PLIF/TLIF group demonstrated significantly more dural tears (p < 0.001), surgical site infections (SSIs) (p = 0.02), and estimated blood loss (EBL) (p < 0.001). After PS adjustments, the LLIF group still showed significantly more endplate injuries (p = 0.03), and the PLIF/TLIF group demonstrated significantly more dural tears (p < 0.001), EBL (p < 0.001), and operating time (p = 0.04). The PLIF/TLIF group showed a trend toward a higher incidence of SSI (p = 0.10). There was no statistically significant difference regarding improvement in the Japanese Orthopaedic Association scores between the 2 surgical procedures (p = 0.77). The CSAs in the spinal canal and foramen were both significantly improved (p < 0.001).

CONCLUSIONS

LLIF is a safe, effective, and less invasive procedure with acceptable complication rates for revision surgery for previously decompressed segments. Therefore, LLIF can be an alternative to PLIF/TLIF for restenosis after posterior decompression surgery.

Functional and radiological outcome of anterior retroperitoneal versus posterior transforaminal interbody fusion in the management of single-level lumbar degenerative disease

OBJECTIVE

In this study the authors compared the anterior lumbar interbody fusion (ALIF) and posterior transforaminal lumbar interbody fusion (TLIF) techniques in a homogeneous group of patients affected by single-level L5–S1 degenerative disc disease (DDD) and postdiscectomy syndrome (PDS). The purpose of the study was to analyze perioperative, functional, and radiological data between the two techniques.

METHODS

A retrospective analysis of patient data was performed between 2015 and 2018. Patients were clustered into two homogeneous groups (group 1 = ALIF, group 2 = TLIF) according to surgical procedure. A statistical analysis of clinical perioperative and radiological findings was performed to compare the two groups. A senior musculoskeletal radiologist retrospectively revised all radiological images.

RESULTS

Seventy-two patients were comparable in terms of demographic features and surgical diagnosis and included in the study, involving 32 (44.4%) male and 40 (55.6%) female patients with an average age of 47.7 years. The mean follow-up duration was 49.7 months. Thirty-six patients (50%) were clustered in group 1, including 31 (86%) with DDD and 5 (14%) with PDS. Thirty-six patients (50%) were clustered in group 2, including 28 (78%) with DDD and 8 (22%) with PDS. A significant reduction in surgical time (107.4 vs 181.1 minutes) and blood loss (188.9 vs 387.1 ml) in group 1 (p < 0.0001) was observed. No significant differences in complications and reoperation rates between the two groups (p = 0.561) was observed. A significant improvement in functional outcome was observed in both groups (p < 0.001), but no significant difference between the two groups was found at the last follow-up. In group 1, a faster median time of return to work (2.4 vs 3.2 months) was recorded. A significant improvement in L5–S1 postoperative lordosis restoration was registered in the ALIF group (9.0 vs 5.0, p = 0.023).

CONCLUSIONS

According to these results, interbody fusion is effective in the surgical management of discogenic pain. Even if clinical benefits were achieved earlier in the ALIF group (better scores and faster return to work), both procedures improved functional outcomes at last follow-up. The ALIF group showed significant reduction of blood loss, shorter surgical time, and better segmental lordosis restoration when compared to the TLIF group. No significant differences in postoperative complications were observed between the groups. Based on these results, the ALIF technique enhances radiological outcome improvement in spinopelvic parameters when compared to TLIF in the management of adult patients with L5–S1 DDD.

Complication Risk in Primary and Revision Minimally Invasive Lumbar Interbody Fusion: A Comparable Alternative to Conventional Open Techniques?

STUDY DESIGN

Retrospective cohort study of prospective patients undergoing minimally invasive lumbar fusion at a single academic institution.

OBJECTIVE

To assess differences in perioperative outcomes between primary and revision MIS (minimally invasive surgical) lumbar interbody fusion patients and compare with those undergoing corresponding open procedures.

METHODS

Patients ≥18 years old undergoing lumbar interbody fusion were grouped by surgical technique: MIS or open. Patients within each group were propensity score matched for comorbidities and levels fused. Patient demographics, surgical factors, and perioperative complication incidences were compared between primary and revision cases using means comparison tests, as appropriate.

RESULTS

Of the 214 lumbar interbody fusion patients included after propensity score matching, 44 (21%) cases were MIS, and 170 (79%) were open. For MIS patients, there were no significant differences between primary and revision cases in estimated blood loss (EBL; 344 vs 299 cm³, P = .682); however, primary cases had longer operative times (301 vs 246 minutes, P = .029). There were no differences in length of stay (LOS), intensive care unit LOS, readmission, and intraoperative or postoperative complications (all P > .05). For open patients, there were no differences between primary and revision cases in EBL (P > .05), although revisions had longer operative times (331 vs 278 minutes, P = .018) and more postoperative complications (61.7% vs 23.8%, P < .001). MIS revision procedures were shorter than open revisions (182 vs 213 minutes, P = .197) with significantly less EBL (294 vs 965 cm³, P < .001), shorter inpatient and intensive care unit LOS, and fewer postoperative complications (all P < .05).

CONCLUSIONS

Clinical outcomes of revision MIS lumbar interbody fusion were similar to those of primary surgery. Additionally, MIS techniques were associated with less EBL, shorter LOS, and fewer perioperative complications than corresponding open revisions.

Defining the MIS-TLIF: A Systematic Review of Techniques and Technologies Used by Surgeons Worldwide

STUDY DESIGN

Systematic review.

OBJECTIVE

To date there is no consensus among surgeons as to what defines an MIS-TLIF (transforaminal lumbar interbody fusion using minimally invasive spine surgery) compared to an open or mini-open TLIF. This systematic review aimed to examine the MIS-TLIF techniques reported in the recent body of literature to help provide a definition of what constitutes the MIS-TLIF, based on the consensus of the majority of surgeons.

METHODS

We created a database of articles published about MIS-TLIF between 2010 and 2018. We evaluated the technical components of the MIS-TLIF including instruments and incisions used as well the order in which key steps are performed.

RESULTS

We could identify several patterns for MIS-TLIF performance that seemed agreed upon by the majority of MIS surgeons: use of paramedian incisions; use of a tubular retractor to perform a total facetectomy, decompression, and interbody cage implantation; and percutaneous insertion of the pedicle-screw rod constructs with intraoperative imaging.

CONCLUSION

Based on this review of the literature, the key features used by surgeons performing MIS TLIF include the use of nonexpandable or expandable tubular retractors, a paramedian or lateral incision, and the use of a microscope or endoscope for visualization. Approaches using expandable nontubular retractors, those that require extensive subperiosteal dissection from the midline laterally, or specular-based retractors with wide pedicle to pedicle exposure are far less likely to be promoted as an MIS-based approach. A definition is necessary to improve the communication among spine surgeons in research as well as patient education.

Classification and Management Algorithm for Postoperative Wound Complications Following Transforaminal Lumbar Interbody Fusion

Study Design

Retrospective study.

Purpose

Postoperative wound complications occurring after transforaminal lumbar interbody fusion (TLIF) are unique, as they can involve different tissue zones (subcutaneous, subfascial, osseous, peri-implant, and disc).

Overview of Literature

Management of postoperative infections occurring after TLIF remains controversial in the context of retention or removal of implants.

Methods

A total of 1,279 consecutive patients (1,520 segments) who underwent TLIF with a minimum follow-up of 1 year were analyzed. Patients with wound complications were classified anatomically into the following five types: type 1, suprafascial necrosis; type 2, wound dehiscence; type 3, pus around screws and rods; type 4, bone marrow edema; and type 5, pus in the disc space. Details pertaining to clinicoradiological and laboratory findings and management were also recorded.

Results

Of the 62 patients (4.8%) with wound complications, there were seven patients in type 1, 35 in type 2, 10 in type 3, four in type 4, and six in type 5. Patients in types 1 and 2 manifested delayed wound healing and were systemically well. In type 1, five patients were managed with resuturing and two were managed conservatively. In type 2, all patients had wound gaping and were managed by debridement, whereas three patients required vacuum-assisted closure. Patients in type 3 had severe back pain and fever, with demonstrable pus around the screw site. Tissue culture identified organisms in 90% of the patients. Patients in type 4 presented with increasing back pain, and magnetic resonance imaging revealed vertebral bone marrow edema. Those in type 5 had severe back pain and fever, with demonstrable pus in the disc space. Patients in types 3–5 required debridement, implant revision/retention, and long-term antibiotics.

Conclusions

The new anatomical classification of surgical site infections could help grade the severity of infection and provide tangible treatment guidelines, resulting in better infection clearance and patient outcomes.

Comparison of Single-Level Open and Minimally Invasive Transforaminal Lumbar Interbody Fusions Presenting a Learning Curve

Background

Comparison of single-level open and minimally invasive transforaminal lumbar interbody fusions (O-TLIF and MI-TLIF) of a single surgeon and presentation of his MI-TLIF learning curve in a retrospective observational cohort study.

Methods

27 MI-TLIF and 31 O-TLIF patients, performed between 03/01/2013 and 03/31/2018, were compared regarding the operative time, blood loss, blood transfusion frequency, postoperative length of stay (LOS), and adverse events. An overall comparison of pre- and postoperative Oswestry Disability Index (ODI) results and Visual Analog Score (VAS) results of low back and leg pain was performed in the case of the two techniques. For a learning curve presentation, the MI-TLIF cases were compared and the optimal operative time was determined.

Results

The gender ratio and age did not differ in the groups. Operative time showed no difference (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (p=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (P=0.88) between the MI-TLIF (161.2 ± 33.7 minutes) and O-TLIF groups (160 ± 33.6 minutes). Intraoperative blood loss was less (

Conclusions

Similar operative time and postoperative quality of life improvement can be achieved by MI-TLIF procedure as with O-TLIF, and additionally LOS and blood loss can be reduced. When comparing parameters, MI-TLIF can be an alternative option for O-TLIF with a similar complication profile. The learning curve of MI-TLIF can be steep, although it depends on the circumstances.

Comparison of rod fracture rates in long spinal deformity constructs after transforaminal versus anterior lumbar interbody fusions: a single-institution analysis

OBJECTIVE

Pseudarthrosis is a common complication of long-segment fusions after surgery for correction of adult spinal deformity (ASD). Interbody fusions are frequently used at the caudal levels of long-segment spinal deformity constructs as adjuncts for anterior column support. There is a paucity of literature comparing rod fracture rates (proxy for pseudarthrosis) in patients undergoing transforaminal lumbar interbody fusion (TLIF) versus anterior lumbar interbody fusion (ALIF) at the caudal levels of the long spinal deformity construct. In this study the authors sought to compare rod fracture rates in patients undergoing surgery for correction of ASD with TLIF versus ALIF at the caudal levels of long spinal deformity constructs.

METHODS

We reviewed clinical records of patients who underwent surgery for correction of ASD between 2008 and 2014 at a single institution. Data including demographics, comorbidities, and indications for surgery, as well as postoperative variables, were collected for each patient. All patients had a minimum 2-year follow-up. Patients were dichotomized into two groups for comparison on the basis of undergoing a TLIF versus an ALIF procedure at the caudal levels of long spinal deformity constructs. The primary outcome of interest was the rate of rod fractures.

RESULTS

A total of 198 patients (TLIF 133 patients; ALIF 65 patients) underwent a long-segment fusion to the sacrum with iliac fixation. The mean ± standard deviation follow-up period was 62.23 ± 29.26 months. Baseline demographic variables were similar in both patient groups. There were no significant differences between groups in the severity of the baseline sagittal plane deformity (i.e., baseline lumbar-pelvic parameters) or the final deformity correction achieved. Mean total recombinant human bone morphogenetic protein 2 (rhBMP-2) dose for L1-sacrum fusion was significantly higher in the ALIF (100 mg) than in the TLIF (62 mg) group. The overall rod failure rate (cases with rod fracture/total cases) within this case series was 19.19% (38/198); 10.60% (21/198) were unilateral rod fractures and 8.58% (17/198) were bilateral rod fractures. At last clinical follow-up, there were no statistically significant differences in bilateral rod fracture rates between the group of patients who had a TLIF procedure and the group who had an ALIF procedure at the caudal levels of the long spinal deformity constructs (TLIF 10.52% vs ALIF 4.61%, p = 0.11). However, the incidence rate (cases per patient follow-up years) for bilateral rod fractures was significantly higher in the TLIF than in the ALIF cohort (TLIF 2.20% vs ALIF 0.70%, p < 0.0001). The reoperation rate for rod fractures was similar between the patient groups (p = 0.40).

CONCLUSIONS

Although both ALIF and TLIF procedures at the caudal levels of long spinal deformity constructs achieved similar and satisfactory deformity correction, ALIFs were associated with a lower rod fracture incidence rate. There were no differences between groups in the prevalence of rod fracture or revision surgery, however, and both groups had low bilateral rod fracture prevalence and incidence rates. One technique is not clearly superior to the other.

Comparison of Stand-alone Lateral Lumbar Interbody Fusion Versus Open Laminectomy and Posterolateral Instrumented Fusion in the Treatment of Adjacent Segment Disease Following Previous Lumbar Fusion Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to compare clinical and radiographic outcomes of patients who underwent stand-alone lateral lumbar interbody fusion (LLIF) to those who underwent posterolateral fusion (PLF) for symptomatic adjacent segment disease (ASD).

SUMMARY OF BACKGROUND DATA

Recent studies have suggested that LLIF can successfully treat ASD; however, there are no studies to date that compare LLIF with the traditional open PLF in this cohort.

METHODS

A total of 47 consecutive patients who underwent LLIF or PLF for symptomatic ASD between January 2007 and August 2016 after failure of conservative management were reviewed for this study. Patient-reported outcomes (PROs) were collected on all patients at preoperative, postoperative, and most recent post-operative visit using the Oswestry Disability Index, Visual Analog Scale (VAS)-Back, and VAS-Leg surveys. Preoperative, immediate postoperative, and most recent postoperative radiographs were assessed for pelvic incidence, fusion, intervertebral disc height, segmental and overall lumbar lordosis (LL). Symptomatic ASD was diagnosed if back pain, neurogenic claudication, or lower extremity radiculopathy presented following a previous lumbar fusion. Preoperative plain radiographs were evaluated for evidence of adjacent segment degeneration.

RESULTS

A total of 47 patients (23 LLIF, 24 PLF) met inclusion criteria. Operative times (P < 0.001) and intraoperative blood loss (P < 0.001) were significantly higher in the PLF group. Patients who underwent PLF were discharged approximately 3 days after the LLIF patients (P < 0.001). PROs in the PLF and LLIF cohorts showed significant and equivalent improvement, with equivalent radiographic fusion rates. LLIF significantly improve segmental lordosis (P < 0.001), total LL (P = 0.003), and disc height (P < 0.001) from preoperative to immediate postoperative and final follow-up (P = 0.004, P = 0.019, P ≤ 0.001, respectively).

CONCLUSION

Although LLIF may provide less perioperative morbidity and shorter length of hospitalization, both techniques are safe and effective approaches to restore radiographic alignment and provide successful clinical outcomes in patients with adjacent segment degeneration following previous lumbar fusion surgery.

LEVEL OF EVIDENCE

3.

State-of-the-Art Reviews: Safety in Complex Spine Surgery

The surgical correction of spinal deformities carries a high risk of perioperative morbidity. As the incidence of debilitating spinal deformities continues to increase, so too does our obligation to search for ways to enhance safety in our delivery of surgical care. Standardized work processes and other lean manufacturing methodologies have the potential to improve efficiency, safety, and hence value in our delivery of surgical care to patients with complex spine pathologies by reducing variability in our work processes. These principles can be applied to patient care from the initial preoperative assessment to long-term postoperative follow-up in the creation of comprehensive protocols that guide the management of these complex patients. Early evidence suggests that short-term outcomes can be improved by implementing packages of systems reform aimed at reducing variability in our work processes; however, contradicting evidence exists on the utility of several specific components of these systems-reform packages.

Safety and performance of a novel articulating cage for transforaminal lumbar interbody fusion in the setting of intraoperative spinal navigation

OBJECTIVE

Transforaminal lumbar interbody fusion (TLIF) has been described as safe and effective procedure for the treatment of low back pain. However, only a few retrospective articles describing articulating cages exist in literature. The aim of this study was to assess the clinical and radiological results, as well as patient safety and complications by using a novel articulating TLIF cage.

PATIENTS AND METHODS

Out of 50 patients, 49 were included in this prospective study. Under computer tomography (CT) guided spinal navigation the TLIF procedure was performed. Clinical outcome scores visual analog scale (VAS), Oswestry disability index (ODI) and short form-36 health survey questionnaire (SF-36) were obtained preoperatively, 6 and 12 months after surgery. Radiological data were acquired preoperatively, after 6 weeks, as well as 6 and 12 postoperatively and included measurements for disc height (anterior/posterior), foraminal height, segmental and global lumbar lordosis.

RESULTS

71% of the included patients have undergone previous lumbar surgery. In total, 80 SYNCHRO® cages have been implanted. The clinical results revealed a highly significant improvement of VAS, ODI and SF-36 after 6 and 12 months, compared to baseline levels (p < 0.05). Radiological analysis revealed a significant increase in anterior and posterior disc height, foraminal height, segmental and global lumbar lordosis postoperatively (p < 0.05). 47 out 49 patients (96%) showed evidence for fusion at the 12 months follow-up. Cage dislocation was found in 1 of 80 implanted cages (1%), which required revision surgery. Two dural tears occurred intraoperatively, which have been fixed. Another two patients needed surgical revision due to infection. The overall complication rate was 10% (n = 5/49).

CONCLUSIONS

The current study delineates satisfactory clinical and radiological results by using a novel articulating TLIF-cage. The implant-related complication rate was acceptable with low revision rate.

Fracture of allograft interbody spacer resulting in post-operative radiculopathy: A case report

BACKGROUND

Allograft interbody spacers are utilized during transforaminal lumbar interbody fusion (TLIF) to reestablish anterior column support and disc height. While the TLIF technique offers many improvements over previous surgical methods, instrumentation and bone graft-related complications such as spacer misplacement or migration, screw fracture or misplacement, or rod breakage continue to be reported. The objective of this manuscript is to report on a fractured allograft interbody spacer that displaced into the neural foramen and resulted in impingement on the exiting nerve root that required revision.

CASE SUMMARY

A 50-year-old male had two-level TLIF with immediate post-operative right L5 radiculopathy. Computed tomography scan demonstrated a fractured allograft interbody spacer that displaced into the right neural foramen and impinged on the exiting L5 nerve root. Revision surgery was performed to remove the broken allograft fragments from the right L5 foramen and the intact portion of the spacer was left in place. The right leg L5 radicular pain resolved. At the last follow up 12 mo after the index procedure, computed tomography scan confirmed sound interbody and posterolateral fusion.

CONCLUSION

Displacement of broken allograft interbody spacer following TLIF procedures can result in neurological sequelae that require revision. To avoid such an occurrence, the authors recommend allowing sufficient time for the reconstitution of the graft in saline prior to use to decrease brittleness, to use an impactor size that is as close as possible to the spacer size and meticulous inspection of the cortical allograft spacer for any visible imperfection prior to insertion.

Postoperative Infection in Patients Undergoing Posterior Lumbosacral Spinal Surgery: A Pictorial Guide for Diagnosis and Early Treatment

Surgical site infections after posterior spinal surgery may lead to spondylodiscitis, pseudarthrosis, correction loss, adverse neurological sequelae, sepsis, and poor outcomes if not treated immediately. Infection rates vary depending on the type and extent of operative procedures, use of instrumentation, and patients' risk factors. Image evaluation is crucial for early diagnosis and should be complementary to clinical routes, laboratory survey, and treatment timing. Magnetic resonance imaging detects early inflammatory infiltration into the vertebrae and soft tissues, including hyperemic changes of edematous marrow, vertebral endplate, and abscess or phlegmon accumulation around the intervertebral disk, epidural, and paravertebral spaces. Aggressive surgical treatment can eradicate infection sources, obtain a stable wound closure, decrease morbidity, and restore spinal integrity. Organ/space infection is defined as any body parts opened to manipulate other than superficial/deep incision. Advanced magnetic resonance imaging evaluating abnormal fluid accumulation, heterogenous contrast enhancement of the endplate erosion due to cage/screw infection is categorized to inform a presumptive diagnosis for early implant salvage. However, patients' defense response, infection severity, bacteriology, treatment timing, spinal stability, and available medical and surgical options must be fully considered. Revision surgery is indicated for pseudarthrosis, implant loosening with correction loss, recalcitrant spondylodiscitis, and adjacent segment diseases for infection control.

Minimally Invasive Transforaminal Lumbar Interbody Fusion: An Attractive Option for Select Failed Backs

Study Design

Retrospective case series.

Purpose

To compare minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) outcomes in primary and revision surgeries.

Overview of Literature

Revision spinal fusion is often associated with an increased risk of approach-related complications. Patients can potentially benefit from the decreased approach-related morbidity associated with MI-TLIF.

Methods

Sixty consecutive MI-TLIF patients (20 failed back [Fa group], 40 primary [Pr group]) who underwent surgery between January 2011 and May 2012 were reviewed after Institutional Review Board approval to compare operative times, blood loss, complications, Oswestry Disability Index (ODI) scores, and Visual Analog Scale (VAS) scores for back and leg pain before surgery and at the last follow-up.

Results

Nineteen revision surgeries were compared with 36 primary surgeries. One failed back and four primary patients were excluded because of inadequate data. The mean follow-up times were 28 months and 24 months in the Pr and Fa groups, respectively. The mean pre- and postoperative ODI scores were 53.18 and 20.23 in the Pr group and 52.01 and 25.72 in the Fa group, respectively (ODI percentage change: Pr group, 60.36%±29.73%; Fa group, 69.32%±13.72%; p=0.304, not significant). The mean pre- and postoperative VAS scores for back pain were 4.77 and 1.75 in the Pr group and 4.1 and 2.0 in the Fa group, respectively, and the percentage changes were statistically significant (VAS back pain percentage change: Pr group, 48.78±30.91; Fa group, 69.32±13.72; p=0.027). The mean pre- and postoperative VAS scores for leg pain were 6.52 and 1.27 in the Pr group and 9.5 and 1.375 in the Fa group, respectively (VAS leg pain percentage change: Pr group, 81.07±29.39; Fa group, 75.72±15.26; p=0.538, not significant). There were no statistically significant differences in operative time and estimated blood loss and no complications.

Conclusions

MI-TLIF outcomes were comparable between primary and revision surgeries. The inherent technique of MI-TLIF is particularly suitable for select failed backs because it exploits the intact paramedian corridor.

Dural Tears in Adult Deformity Surgery: Incidence, Risk Factors, and Outcomes

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Describe the rate of dural tears (DTs) in adult spinal deformity (ASD) surgery. Describe the risk factors for DT and the impact of this complication on clinical outcomes.

METHODS

Patients with ASD undergoing surgery between 2008 and 2014 were separated into DT and non-DT cohorts; demographics, operative details, radiographic, and clinical outcomes were compared. Statistical analysis included t tests or χ² tests as appropriate and a multivariate analysis.

RESULTS

A total of 564 patients were identified. The rate of DT was 10.8% (n = 61). Patients with DT were older (61.1 vs 56.5 years, P = .005) and were more likely to have had prior spine surgery (odds ratio [OR] = 2.0, 95% confidence interval [CI] = 1.2-3.3, P = .007). DT patients had higher pelvic tilt, lower lumbar lordosis, and greater pelvic-incidence lumbar lordosis mismatch than non-DT patients (P < .05). DT patients had longer operative times (424 vs 375 minutes, P = .008), were more likely to undergo interbody fusions (OR = 2.0, 95% CI = 1.1-3.6, P = .021), osteotomies (OR = 2.2, 95% CI = 1.1-4.0, P = .012), and decompressions (OR = 2.3, 95% CI = 1.3-4.3, P = .003). In our multivariate analysis, only decompressions were associated with an increased risk of DT (OR = 3.2, 95% CI = 1.4-7.6, P = .006). There were no significant differences in patient outcomes at 2 years.

CONCLUSIONS

The rate of DT was 10.8% in an ASD cohort. This is similar to rates of DT reported following surgery for degenerative pathology. A history of prior spine surgery, decompression, interbody fusion, and osteotomies are all associated with an increased risk of DT, but decompression is the only independent risk factor for DT.

Biomechanical analysis of the posterior bony column of the lumbar spine

Background

Each part of the rear bone structure can become an anchor point for an attachment device. The objective of this study was to evaluate the stiffness and strength of different parts of the rear lumbar bone structure by axial compression damage experiments.

Methods

Five adult male lumbar bone structures from L2 to L5 were exposed. The superior and inferior articular processes, upper and lower edges of the lamina, and upper and lower edges of the spinous process were observed and isolated and then divided into six groups (n = 10). The specimens were placed between the compaction disc and the load platform in a universal testing machine, which was first preloaded to 5.0 N tension to eliminate water on the surface and then loaded to the specimen curve decline at a constant tension loading rate of 0.01 mm/s, until the specimens had been destroyed.

Results

Significant differences in mechanical properties were found among different parts of the rear lumbar bone structure. Compared with other parts, the lower edge of the lamina has good mechanical properties, which have a high modulus of elasticity; the superior and inferior articular processes have greater ultimate strength, which can withstand greater compressive loads; and the mechanical properties of the spinous process are poor, and it is significantly stiffer and weaker than the lamina and articular processes.

Conclusion

These data can be useful in future spinal biomechanics research leading to better biomechanical compatibility and provide theoretical references for spinal implant materials.

Lumbar segmental artery pseudoaneurysm after L5 pedicle screw placement. A rare vascular complication

Posterior lumbar screw fixation is a common surgical procedure nowadays. However, it can sometimes produce complications that can be devastating. One of the less common causes of major complication is the misplacement of a pedicle screw. This highlights the importance of being methodical when placing pedicle screws, and checking that the pathway has been created correctly and their placement. We present a case of a massive bleed after a pedicular screw placement during lumbar canal stenosis surgery. Screw malposition led to intraoperative haemodynamic instability after failed attempts to control bleeding in the surgical site. Contrast enhanced CT imaging revealed a lumbar intersegmentary artery injury that was eventually controlled by means of a coil embolisation.

Extreme lateral interbody fusion in spinal revision surgery: clinical results and complications

PURPOSE OF THE STUDY

To evaluate clinical outcomes and complications of extreme lumbar interbody fusion (XLIF) in spinal revision surgery comparing our data with the available literature evidence about other fusion techniques.

MATERIALS AND METHODS

Retrospective analysis of patients underwent revision surgery with XLIF as interbody fusion technique. Demographic, comorbidity, surgical data, clinical results, and intraoperative and postoperative complications were recorded.

RESULTS

36 patients, with a minimum follow-up of 28 ± 11.5 months, were included in the analysis. 41 levels were fused with XLIF. The mean number of previous spine surgery was 1.5 ± 0.7. Mean improvement in back pain and leg pain on VAS was 5.6 ± 1.4 (p < 0.01) and 3.5 ± 2 (p < 0.01), respectively. Mean improvement in the ODI score was 30.3 ± 7.3 (p < 0.01). 1 vertebral endplate fracture during interbody space preparation was reported during lateral approach. 5 patients (13.8%) complained quadriceps weakness and anterior thigh hypoesthesia fully recovered after 3 months from surgery, and in one case, a transient contralateral radiculopathy was observed. No implant failure was detected at final follow-up.

CONCLUSIONS

XLIF is a reasonably safe and effective fusion technique in revision surgery that allows valid arthrodesis avoiding scarred tissue created by previous surgical approaches. Especially, XLIF reduces the risk of nerve root lesions, postoperative radiculitis, and durotomies compared to posterior fusion techniques.

Dural Traction a Possible Cause of Hemodynamic Changes During Single-Level Transforaminal Lumbar Interbody Fusion

BACKGROUND

Lumbar spinal surgery may be associated with electrophysiologic and hemodynamic abnormalities during the procedure.

CASE DESCRIPTION

A 58-year-old man with grade II L4-5 spondylolisthesis and degenerative changes underwent single-level transforaminal lumbar interbody fusion. During decompression of the L4 foramina, distraction of the disc space, and placement of the interbody cage and pedicle screws, episodes of extreme bradycardia with up to 5 seconds of asystole were detected on electrocardiogram and invasive hemodynamic monitoring. The events correlated with and possibly could have been a result of traction on the dura mater.

CONCLUSIONS

Anesthesia providers should be aware of electrophysiologic and hemodynamic abnormalities during lumbar spinal surgery and the need to respond appropriately with sympathomimetic or vagolytic interventions.

Complication avoidance with pre-operative screening: insights from the Seattle spine team

Complication rates for complex adult lumbar scoliosis surgery are unacceptably high. Standardized preoperative evaluation protocols have been shown to significantly reduce the likelihood of a spectrum of negative outcomes associated with complex adult lumbar scoliosis surgery. To increase patient safety and reduce complication risk, an entire medical and surgical team should work together to care for adult lumbar scoliosis patients. This article describes preoperative patient evaluation strategies with a particular focus on adult lumbar scoliosis surgery involving six or more levels of spinal fusion. Domains considered include recent preoperative evaluation literature, predictive risk modeling, the appropriate management of medical conditions, and the composition and activities of a multidisciplinary conference review team. An evidence-based comprehensive systematic preoperative surgical evaluation process is described.

Minimally invasive transforaminal lumbar interbody fusion with the ROSA(TM) Spine robot and intraoperative flat-panel CT guidance

BACKGROUND

Circumferential arthrodesis is commonly used to treat degenerative lumbar diseases. Minimally invasive techniques may enable faster recovery and reduce the incidence of postoperative infections.

METHODS

We report on the surgical technique of a transforaminal lumbar interbody fusion (TLIF) procedure performed with the assistance of a new robotic device (ROSA(TM) Spine) and intraoperative flat-panel CT guidance.

CONCLUSIONS

The combined use of this new robotic device and intraoperative CT enables accurate and safe arthrodesis in the treatment of degenerative lumbar disc diseases.

Preoperative retrolisthesis as a risk factor of postdecompression lumbar disc herniation

OBJECT

In this study, the authors aimed to identify specific risk factors for postdecompression lumbar disc herniation (PDLDH) in patients who have not undergone discectomy and/or fusion.

METHODS

Between 2007 and 2012, 493 patients with lumbar spinal stenosis underwent bilateral partial laminectomy without discectomy and/or fusion in a single hospital. Eighteen patients (herniation group [H group]: 15 men, 3 women; mean age 65.1 years) developed acute sciatica as a result of PDLDH within 2 years after surgery. Ninety patients who did not develop postoperative acute sciatica were selected as a control group (C group: 75 men, 15 women; mean age 65.4 years). Patients in the C group were age and sex matched with those in the H group. The patients in the groups were also matched for decompression level, number of decompression levels, and surgery date. The radiographic variables measured included percentage of slippage, intervertebral angle, range of motion, lumbar lordosis, disc height, facet angle, extent of facet removal, facet degeneration, disc degeneration, and vertebral endplate degeneration. The threshold for PDLDH risk factors was evaluated using a continuous numerical variable and receiver operating characteristic curve analysis. The area under the curve was used to determine the diagnostic performance, and values greater than 0.75 were considered to represent good performance.

RESULTS

Multivariate analysis revealed that preoperative retrolisthesis during extension was the sole significant independent risk factor for PDLDH. The area under the curve for preoperative retrolisthesis during extension was 0.849; the cutoff value was estimated to be a retrolisthesis of 7.2% during extension.

CONCLUSIONS

The authors observed that bilateral partial laminectomy, performed along with the removal of the posterior support ligament, may not be suitable for lumbar spinal stenosis patients with preoperative retrolisthesis greater than 7.2% during extension.

Unintended durotomy in lumbar degenerative spinal surgery: a 10-year systematic review of the literature

OBJECT

Unintended durotomy is a common occurrence during lumbar spinal surgery, particularly in surgery for degenerative spinal conditions, with the reported incidence rate ranging from 0.3% to 35%. The authors performed a systematic literature review on unintended lumbar spine durotomy, specifically aiming to identify the incidence of durotomy during spinal surgery for lumbar degenerative conditions. In addition, the authors analyzed the incidence of durotomy when minimally invasive surgical approaches were used as compared with that following a traditional midline open approach.

METHODS

A MEDLINE search using the term “lumbar durotomy” (under the 2015 medical subject heading [MeSH] “cerebrospinal fluid leak”) was conducted on May 13, 2015, for English-language medical literature published in the period from January 1, 2005, to May 13, 2015. The resulting papers were categorized into 3 groups: 1) those that evaluated unintended durotomy rates during open-approach lumbar spinal surgery, 2) those that evaluated unintended durotomy rates during minimally invasive spine surgery (MISS), and 3) those that evaluated durotomy rates in comparable cohorts undergoing MISS versus open-approach lumbar procedures for similar lumbar pathology.

RESULTS

The MEDLINE search yielded 116 results. A review of titles produced 22 potentially relevant studies that described open surgical procedures. After a thorough review of individual papers, 19 studies (comprising 15,965 patients) pertaining to durotomy rates during open-approach lumbar surgery were included for analysis. Using the Oxford Centre for Evidence-Based Medicine (CEBM) ranking criteria, there were 7 Level 3 prospective studies and 12 Level 4 retrospective studies. In addition, the authors also included 6 studies (with a total of 1334 patients) that detailed rates of durotomy during minimally invasive surgery for lumbar degenerative disease. In the MISS analysis, there were 2 prospective and 4 retrospective studies. Finally, the authors included 5 studies (with a total of 1364 patients) that directly compared durotomy rates during open-approach versus minimally invasive procedures. Studies of open-approach surgery for lumbar degenerative disease reported a total of 1031 durotomies across all procedures, for an overall durotomy rate of 8.11% (range 2%–20%). Prospectively designed studies reported a higher rate of durotomy than retrospective studies (9.57% vs 4.32%, p = 0.05). Selected MISS studies reported a total of 93 durotomies for a combined durotomy rate of 6.78%. In studies of matched cohorts comparing open-approach surgery with MISS, the durotomy rates were 7.20% (34 durotomies) and 7.02% (68), respectively, which were not significantly different.

CONCLUSIONS

Spinal surgery for lumbar degenerative disease carries a significant rate of unintended durotomy, regardless of the surgical approach selected by the surgeon. Interpretation of unintended durotomy rates for lumbar surgery is limited by a lack of prospective and cohort-matched controlled studies.

Analysis of 1014 consecutive operative cases to determine the utility of intraoperative neurophysiological data

Introduction:

Intraoperative neurophysiological monitoring (IOM) during neurosurgical procedures has become the standard of care at tertiary care medical centers. While prospective data regarding the clinical utility of IOM are conspicuously lacking, retrospective analyses continue to provide useful information regarding surgeon responses to reported waveform changes.

Methods:

Data regarding clinical presentation, operative course, IOM, and postoperative neurological examination were compiled from a database of 1014 cranial and spinal surgical cases at a tertiary care medical center from 2005 to 2011. IOM modalities utilized included somatosensory evoked potentials, transcranial motor evoked potentials, pedicle screw stimulation, and electromyography. Surgeon responses to changes in IOM waveforms were recorded.

Results:

Changes in IOM waveforms indicating potential injury were present in 87 of 1014 cases (8.6%). In 23 of the 87 cases (26.4%), the surgeon responded by repositioning the patient (n = 12), repositioning retractors (n = 1) or implanted instrumentation (n = 9), or by stopping surgery (n = 1). Loss of IOM waveforms predicted postoperative neurological deficit in 10 cases (11.5% of cases with IOM changes).

Conclusions:

In the largest IOM series to date, we report that the surgeon responded by appropriate interventions in over 25% of cases during which there were IOM indicators of potential harm to neural structures. Prospective studies remain to be undertaken to adequately evaluate the utility of IOM in changing surgeon behavior. Our data is in agreement with previous observations in indicating a trend that supports the continued use of IOM.

Case Series of Anterior Intervertebral Graft Extrusions in Transforaminal Lumbar Interbody Fusion Surgeries

BACKGROUND

According to the published reports, revision surgery is sometimes recommended even in patients with asymptomatic anterior lumbar intervertebral graft migrations. The main purpose of this chart review study was to report on the clinical course and outcomes of patients who had anterior intervertebral graft extrusions after transforaminal lumbar interbody fusion (TLIF).

METHODS

From July 2002 to July 2014, 1259 consecutive TLIF surgeries were performed. These were reviewed, and patients who had anterior intervertebral graft extrusions were identified.

RESULTS

The incidence of graft extrusion was 0.6% (7 of 1259 patients). There were 6 female patients and 1 male patient with an average age of 65.7 years (range, 44-80 years). All patients underwent TLIF with bilateral pedicle screw fixation, and 6 received recombinant human bone morphogenetic protein-2. Graft migrations were diagnosed between 5 days and 8 months postoperatively except for 2 cases in which migration occurred intraoperatively. The patients were closely followed for an average of 27.4 months (range, 12-43 months). All patients remained asymptomatic during the follow-up period and had solid fusion despite extrusions with an average time to fusion of 13 months (range, 10-18 months). No other adverse events occurred during the follow-up period.

CONCLUSIONS

The risks of additional and highly invasive revision surgery should be weighed against the potential short-term and long-term complications associated with graft extrusions or migrations. It was demonstrated that fusion may take longer but can be achieved, and close observation may be adequate for asymptomatic patients.

Magnetic resonance neurography in analysis of operative safety of transforaminal lumbar interbody fusion in Chinese subjects

OBJECTIVE

To measure relevant anatomical variables of lumbosacral nerve root and adjacent structures by magnetic resonance neurography (MRN) and analyze operative safety of transforaminal lumbar interbody fusion (TLIF) in Chinese subjects.

METHODS

Twelve normal healthy volunteers (six men, six women) underwent MRN of lumbosacral nerve roots at 3.0 T. Three-dimensional imaging was reconstructed with Osirix software and the following anatomic variables measured: (i) distance between nerve root and upper pedicle; (ii) distance between nerve root and lower pedicle; (iii) angle between nerve root and sagittal plane; (iv) distance between upper and lower nerve roots; and (v) distance between upper and lower pedicles.

RESULTS

Good images of the L(1)-L(5) nerve roots were obtained by MRN technology in all 12 volunteers. The distance between nerve root and upper pedicle and the angle between nerve roots and the sagittal plane gradually diminished from L(1) to L(5). However, there were no significant variations in the distance between nerve root and lower pedicle or between upper and lower pedicles. From L(1 -2) to L(4 -5), the distances between upper and lower pedicles, which are closely related to the operating space for TLIF in Chinese men and women, were less than 10 mm in most subjects and were significantly smaller in women than in men. The variables did not differ significantly between the left and right sides of the same segment.

CONCLUSION

Based on the above anatomical study and measurement analysis, we believe that TLIF puts the upper nerve root at risk in some Chinese patients. However, this conclusion requires confirmation by anatomical study of large samples and clinical validation.

Intraoperative and perioperative complications in minimally invasive transforaminal lumbar interbody fusion: a review of 513 patients

OBJECT

Transforaminal lumbar interbody fusion (TLIF) has become one of the preferred procedures for circumferential fusion in the lumbar spine. Over the last decade, advances in surgical techniques have enabled surgeons to perform the TLIF procedure through a minimally invasive approach (MI-TLIF). There are a few studies reported in the medical literature in which perioperative complication rates of MI-TLIF were evaluated; here, the authors present the largest cohort series to date. They analyzed intraoperative and perioperative complications in 513 consecutive MI-TLIF–treated patients with lumbar degenerative disc disease.

METHODS

The authors performed a retrospective review of prospectively collected data on 513 consecutive patients treated over a 10-year period for lumbar degenerative disc disease using MI-TLIF. All patients undergoing either a first-time or revision 1- or 2-level MI-TLIF procedure were included in the study. Demographic, intraoperative, and perioperative data were collected and analyzed using bivariate analyses (Student t-test, analysis of variance, odds ratio, chi-square test) and multivariate analyses (logistic regression).

RESULTS

A total of 513 patients underwent an MI-TLIF procedure, and the perioperative complication rate was 15.6%. The incidence of durotomy was 5.1%, and the medical and surgical infection rates were 1.4% and 0.2%, respectively. A statistically significant increase in the infection rate was seen in revision MI-TLIF cases, and the same was found for the perioperative complication rate in multilevel MI-TLIF cases. Instrumentation failure occurred in 2.3% of the cases. After analysis, no statistically significant difference was seen in the rates of durotomy during revision and multilevel surgeries. There was no significant difference between the complication rates when stratified according to presenting diagnosis.

CONCLUSIONS

To the authors' knowledge, this is the largest study of perioperative complications in MI-TLIF in the literature. A total of 513 patients underwent MI-TLIF (perioperative complication rate 15.6%). The most common complication was a durotomy (5.1%), and there was only 1 surgical wound infection (0.2%). There were significantly more perioperative infections in revision MI-TLIF cases and more perioperative complications in multilevel MI-TLIF cases. The results of this study suggest that MI-TLIF has a similar or better perioperative complication profile than those documented in the literature for open-TLIF treatment of degenerative lumbar spine disease.

Effectiveness and safety of transforaminal lumbar interbody fusion in patients with previous laminectomy

PURPOSE

To determine the efficacy and safety of transforaminal lumbar interbody fusion (TLIF) for revision lumbar spine surgery in patients with previous laminectomy. The secondary objective was to evaluate the clinical and radiological outcome after such a procedure.

METHODS

Retrospective case series study. Eighty-two patients were included. There were 48 women (58.5 %) and 34 men (41.5 %) with a mean age of 51 years (range 26-84) at the time of index procedure. The outpatient and inpatient charts were reviewed to identify patients' demographic data, preoperative, perioperative, and postoperative data. The outcome measures were assessed by Oswestry Disability Index (ODI) and visual analog scale (VAS) for back and leg pain. An independent spine surgeon and musculoskeletal radiologist reviewed the imaging studies.

RESULTS

The average operative time was 160 min (range 131-250). The average estimated blood loss was 652 cc (100-1,400 cc). Nineteen patients (23.1 %) required blood transfusion. Five patients (6 %) had dural tear. One patient (1.2 %) had a surgical site infection. Two patients (2.4 %) had thromboembolic events. The average hospital stay was 3.8 days (2-5 days). At a mean follow-up of 28 months, there were statically significant improvement in the ODI and VAS for back and leg pain. None of the patients' radiographs showed hardware failure or pedicle screw loosening and no patient returned to the operating room for pseudarthrosis.

CONCLUSIONS

The current study confirmed that TLIF approach in patients with previous laminectomy is effective and safe with good outcomes.