Technical Consideration for TLIF Cage Retrieval and Deformity Correction With Anterior Interbody Fusion in Lumbar Revision Surgeries

Surgical outcomes of anterior lumbar interbody fusion in revision lumbar interbody fusion surgery

BACKGROUNDS

Anterior lumbar interbody fusion (ALIF) is an attractive option for revision lumbar interbody fusion as it provides wide access for implant removal and accommodation of large interbody grafts for fusion. However, revision lumbar interbody fusion surgery has not been found to result in significantly better functional outcomes compared with other approaches. To date, no prognostic factors of anterior lumbar interbody fusion in revision lumbar interbody fusion have been reported. In this study, we investigated the surgical results and possible prognostic factors of anterior lumbar interbody fusion in revision lumbar interbody fusion.

METHODS

Patients who received revision interbody fusion surgery between January 2010 and May 2018 in our hospital were reviewed. Clinical outcomes were determined according to whether the VAS score improvement in back pain and leg pain reached the minimum clinically important difference (MCID) and Macnab criteria. Radiographic outcomes were assessed with fusion rate, preoperative, and postoperative lumbar lordosis. Operative-relative factors that may affect clinical outcomes, such as BMI, existence of cage migration, cage subsidence, pseudarthrosis, previous procedure, and number of fusion segments, were collected and analyzed.

RESULTS

A total of 22 consecutive patients who received ALIF for revision interbody fusion surgery were included and analyzed. There were 9 men and 13 women with a mean age at operation of 56 years (26-78). The mean follow-up was 73 months (20-121). The minimal clinically important difference (MCID) was reached in 11 (50%) of the patients for back pain and 14 (64%) for leg pain. According to the modified Macnab criteria, 73% of the patients in this study had successful outcomes (excellent or good). The pain and lumbar lordosis had significant improvement (P < 0.05). Preoperative fusion segment ≥ 2 was shown to be a poor prognostic factor for back pain improvement reaching MCID (P = 0.043).

CONCLUSIONS

ALIF has proven effective for revision lumbar fusion surgery, yielding positive clinical and radiographic results. However, having two or more preoperative fusion segments can negatively impact back pain improvement.

LEVEL OF EVIDENCE

IV.

Postoperative bone graft migration into the thecal sac and shifting down to the lower level after an endoscopic lumbar interbody fusion: a case report

BACKGROUND

Postoperative bone graft migration (PBGM) is a fairly rare spinal postoperative complication. Its occurrence after endoscopic surgery has rarely been reported in the literature so far. This is a case report of a 52-year-old male occurring PBGM into the thecal sac in the 8th days after an endoscopic lumbar interbody fusion (ELIF), which can make surgeons more minded with such serious rare complication after BGM.

CASE PRESENTATION

A 52-year-old male patient, underwent a L4-5 ELIF, presented with an acute radiculopathy on right leg and urinary incontinence in the 8^th postoperative day. An emergency lumbar Computed Tomography(CT scan) and Magnetic Resonance Imaging (MRI) demonstrated bone graft migration into the thecal sac at the L4-5 level, and shifting down to the lower level. The revision surgery was performed at once successfully. Finally, the patient got well managed before discharge.

CONCLUSION

Supported by this case report, we believe that PBGM into the thecal sac is a rare but horrible complication of ELIF. However, too much volume of bone graft and its posterior placement are more prone to developing this complication. Finally, we are not sure that the outcome presented in this study will be repeated in future cases.

Risk Assessment of Anterior Lumbar Interbody Fusion Access in Degenerative Spinal Conditions

STUDY DESIGN

This was a retrospective cohort study.

OBJECTIVE

Develop an evidence-based preoperative risk assessment scoring system for patients undergoing anterior lumbar interbody fusion (ALIF).

SUMMARY OF BACKGROUND DATA

ALIF may hold advantages over other fusion techniques in sagittal restoration and fusion rates, though it introduces unique risks to vascular and abdominal structures and thus possibly increased risk of operative morbidity.

METHODS

Primary, 1 or 2-level ALIFs were identified in a surgical registry. Baseline characteristics were recorded. Axial magnetic resonance imagings at L4-L5 and L5-S1 were reviewed for vascular confluence/bifurcation or anomalous structures, and measured for operative window size/slope. To assess favorable outcomes, a clinical grade was calculated: (clinical grade=blood loss×operative duration), higher value indicating poorer outcome. To establish a risk scoring system, a base risk score algorithm was established and stratified into 5 categories: high, high to intermediate, intermediate, intermediate to low, and low. Modifiers to base risk score included age, body mass index, operative level, history of bone morphogenic protein use, calcified vasculature, spondylolisthesis grade, working window size and slope, and abnormal vasculature. Modifiers were weighted for contribution to surgical risk. A total risk score was calculated and evaluated for strength of association with clinical outcome grades by Pearson correlation coefficient.

RESULTS

A total of 65 patients were included. Mean clinical outcome grade was 5.6, mean total risk score 21.3±21.5. Multilevel procedures (L4-S1) mean total risk score was 57.3±7.8. L4-L5 mean total risk score was 23.6±5.2; L5-S1 mean total risk score 8.3±6.6. Correlation analysis demonstrated a significant and strong relationship (| r |=0.753; P <0.001) between total risk scores and clinical outcome grades.

CONCLUSION

Calculated ALIF risk scores significantly correlated with operative duration and blood loss. This scoring system represents a potential framework to facilitate clinical decision-making and risk assessment for potential ALIF candidates with degenerative spinal pathologies.

Utilization of lateral anterior lumbar interbody fusion for revision of failed prior TLIF: illustrative case

BACKGROUND

The use of the lateral decubitus approach for L5–S1 anterior lumbar interbody fusion (LALIF) is a recent advancement capable of facilitating single-position surgery, revision operations, and anterior column reconstruction. To the authors’ knowledge, this is the first description of the use of LALIF at L5–S1 for failed prior transforaminal lumbar interbody fusion (TLIF) and anterior column reconstruction. Using an illustrative case, the authors discuss their experience using LALIF at L5–S1 for the revision of pseudoarthrosis and TLIF failure.

OBSERVATIONS

The patient had prior attempted L2 to S1 fusion with TLIF but suffered from hardware failure and pseudoarthrosis at the L5–S1 level. LALIF was used to facilitate same-position revision at L5–S1 in addition to further anterior column revision and reconstruction by lateral lumbar interbody fusion at the L1–2 level. Robotic posterior T10–S2 fusion was then added to provide stability to the construct and address the patient’s scoliotic deformity. No complications were noted, and the patient was followed until 1 year after the operation with a favorable clinical and radiological result.

LESSONS

Revision of a prior failed L5–S1 TLIF with an LALIF approach has technical challenges but may be advantageous for single position anterior column reconstruction under certain conditions.

Pseudarthrosis and Rod Fracture Rates After Transforaminal Lumbar Interbody Fusion at the Caudal Levels of Long Constructs for Adult Spinal Deformity Surgery

BACKGROUND

Interbody fusion at the caudal levels of long constructs for adult spinal deformity (ASD) surgery is used to promote fusion and secure a solid foundation for maintenance of deformity correction. We sought to evaluate long-term pseudarthrosis, rod fracture, and revision rates for TLIF performed at the base of a long construct for ASD.

METHODS

We reviewed 316 patients who underwent TLIF as a component of ASD surgery for medical comorbidities, surgical characteristics, and rate of unplanned reoperation for pseudarthrosis or instrumentation failure at the TLIF level. Fusion grading was assessed after revision surgery for pseudarthrosis at the TLIF level.

RESULTS

Rate of pseudarthrosis at the TLIF level was 9.8% (31/316), and rate of rod fractures was 7.9% (25/316). The rate of revision surgery at the TLIF level was 8.9% (28/316), and surgery was performed at a mean of 20.4 ± 16 months from the index procedure. Current smoking status (odds ratio 3.34, P = 0.037) was predictive of pseudarthrosis at the TLIF site. At a mean follow-up of 43 ± 12 months after revision surgery, all patients had achieved bony union at the TLIF site.

CONCLUSIONS

At 3-year follow-up, the rate of pseudarthrosis after TLIF performed at the base of a long fusion for ASD was 9.8%, and the rate of revision surgery to address pseudarthrosis and/or rod fracture was 8.9%. All patients were successfully treated with revision interbody fusion or posterior augmentation of the fusion mass, without need for further revision procedures at the TLIF level.

Using an Extreme Lateral Interbody Fusion (XLIF) in Revising Failed Transforaminal Lumbar Interbody Fusion (TLIF) With Exchange of Cage

Minimally invasive techniques have gained popularity in spine surgery in recent years. Extreme lateral interbody fusion (XLIF) is one of these techniques. The rapid increase in the use of this approach in either primary or revision surgeries is related to its several advantages including less operative time, less blood loss and reduced length of hospital stay with fast recovery. We report a case of a failed transforaminal lumbar interbody fusion (TLIF) in L4-L5 level, one year after the primary procedure with persistent pain due to failed fusion. Underwent revision, by using XLIF with the removal of old cage and exchange with new large cage. Revision of failed interbody fusion can be achieved through anterior, posterior or lateral approach. The decision to proceed with either method depends on several factors, including previous surgeries, fibrosis and risk of neurovascular injury and surgeon's preference. XLIF approach should be considered in revision surgeries of failed interbody fusion. As it can provide several advantages compared to anterior or posterior approaches, in terms of better fusion rates and lower risk of neurovascular injuries by avoiding the use of the previous passage.

Anterior Lumbar Interbody Fusion With Cage Retrieval for the Treatment of Pseudarthrosis After Transforaminal Lumbar Interbody Fusion: A Single-Institution Case Series

BACKGROUND

The treatment of pseudarthrosis after transforaminal lumbar interbody fusion (TLIF) can be challenging, particularly when anterior column reconstruction is required. There are limited data on TLIF cage removal through an anterior approach.

OBJECTIVE

To assess the safety and efficacy of anterior lumbar interbody fusion (ALIF) as a treatment for pseudarthrosis after TLIF.

METHODS

ALIFs performed at a single academic medical center were reviewed to identify cases performed for the treatment of pseudarthrosis after TLIF. Patient demographics, surgical characteristics, perioperative complications, and 1-yr radiographic data were collected.

RESULTS

A total of 84 patients were identified with mean age of 59 yr and 37 women (44.0%). A total of 16 patients (19.0%) underwent removal of 2 interbody cages for a total of 99 implants removed with distribution as follows: 1 L2/3 (0.9%), 6 L3/4 (5.7%), 37 L4/5 (41.5%), and 55 L5/S1 (51.9%). There were 2 intraoperative venous injuries (2.4%) and postoperative complications were as follows: 7 ileus (8.3%), 5 wound-related (6.0%), 1 rectus hematoma (1.1%), and 12 medical complications (14.3%), including 6 pulmonary (7.1%), 3 cardiac (3.6%), and 6 urinary tract infections (7.1%). Among 58 patients with at least 1-yr follow-up, 56 (96.6%) had solid fusion. There were 5 cases of subsidence (6.0%), none of which required surgical revision. Two patients (2.4%) required additional surgery at the level of ALIF for pseudarthrosis.

CONCLUSION

ALIF is a safe and effective technique for the treatment of TLIF cage pseudarthrosis with a favorable risk profile.

[Comparison of the effectiveness of oblique lumbar interbody fusion and posterior lumbar interbody fusion for treatment of Cage dislodgement after lumbar surgery]

OBJECTIVE

To compare the clinical and radiological effectiveness of oblique lumbar interbody fusion (OLIF) and posterior lumbar interbody fusion (PLIF) in the treatment of Cage dislodgement after lumbar surgery.

METHODS

The clinical data of 40 patients who underwent revision surgery due to Cage dislodgement after lumbar surgery betweem April 2013 and March 2017 were retrospectively analyzed. Among them, 18 patients underwent OLIF (OLIF group) and 22 patients underwent PLIF (PLIF group) for revision. There was no significant difference between the two groups in age, gender, body mass index, intervals between primary surgery and revision surgery, number of primary fused levels, disc spaces of Cage dislodgement, and visual analogue scale (VAS) scores of low back pain and leg pain, Oswestry disability index (ODI), the segmental lordosis (SL) and disc height (DH) of the disc space of Cage dislodgement, and the lumbar lordosis (LL) before revision ( P>0.05). The operation time, intraoperative blood loss, hospital stay, and complications of the two groups were recorded and compared. The VAS scores of low back pain and leg pain were evaluated at 3 days, 3, 6, and 12 months after operation, and the ODI scores were evaluated at 3, 6, and 12 months after operation. The SL and DH of the disc space of Cage dislodgement and LL were measured at 12 months after operation and compared with those before operation. CT examination was performed at 12 months after operation, and the fusion of the disc space implanted with new Cage was judged by Bridwell grading standard.

RESULTS

The intraoperative blood loss in the OLIF group was significantly less than that in the PLIF group ( t=-12.425, P=0.000); there was no significant difference between the two groups in the operation time and hospital stay ( P>0.05). Both groups were followed up 12-30 months, with an average of 18 months. In the OLIF group, 2 patients (11.1%) had thigh numbness and 1 patient (5.6%) had hip flexor weakness after operation; 2 patients (9.1%) in the PLIF group had intraoperative dural sac tear. The other patients' incisions healed by first intention without early postoperative complications. There was no significant difference in the incidence of complications between the two groups ( χ 2=0.519, P=0.642). The VAS scores of low back pain and leg pain, and the ODI score of the two groups at each time point after operation were significantly improved when compared with those before operation ( P<0.05); there was no significant difference between the two groups at each time point after operation ( P>0.05). At 12 months after operation, SL, LL, and DH in the two groups were significantly increased when compared with preoperative ones ( P<0.05); SL and DH in the OLIF group were significantly improved when compared with those in the PLIF group ( P<0.05), and there was no significant difference in LL between the two groups ( P>0.05). CT examination at 12 months after operation showed that all the operated disc spaces achieved bony fusion. According to the Bridwell grading standard, 12 cases were grade Ⅰ and 6 cases were grade Ⅱ in the OLIF group, and 13 cases were grade Ⅰ and 9 cases were grade Ⅱ in the PLIF group; there was no significant difference between the two groups ( Z=-0.486, P=0.627). During follow-up, neither re-displacement or sinking of Cage, nor loosening or fracture of internal fixation occurred.

CONCLUSION

OLIF and PLIF can achieve similar effectiveness in the treatment of Cage dislodgement after lumbar surgery. OLIF can further reduce intraoperative blood loss and restore the SL and DH of the disc space of Cage dislodgement better.

Revision surgery for non-union in adult spinal deformity

As adult spinal deformity surgery is performed more and more, the spine surgeon is faced with the challenge to treat pseudoarthrosis. The presentation may vary, from asymptomatic patients, who should be observed in most of the cases, to patients with acute episode of broken rods, and or chronic pain with often trunk imbalance. In some instances, patients will present with neurologic symptoms. The evaluation of such patients must start with a good understanding of why the surgery failed first place. Poor host, smoking, lack of anterior column support, poor sagittal balance, lack of fusion, poor construct. Often a combination of all of the above is encountered. The workup for such cases consists of imaging studies (with often a CT myelogram as the excessive metal artifact will render the MRI imaging useless), nutrition labs, DEXA scan, EOS films and internal medicine or cardiology consult for risk stratification as this may represent major surgery. Indication of surgery is mostly based on pain and imbalance and/or poor function. The surgeon planning a revision adult deformity surgery has many tasks to perform: Identify and avoid the reasons that lead to failure of the previous surgeries. Plan the anterior column reconstruction either through posterior or anterior interbody fusion. Restore the global alignment through anterior or posterior osteotomies to achieve sagittal and coronal balance. Obtain a solid fixation with sufficient levels above and below the osteotomies sites with in some cases the use of pelvic screws and four rods (Quad-Rod) techniques. The use of bone graft (either autologous, allograft, bone graft enhancers and inducer) agents. The requirement of decompression either through a virgin spine or a previous laminectomy bed. Despite the extent of these surgeries and the potential for immediate postoperative complications, the outcome is in most cases satisfactory if these goals are achieved. In this review, the authors explore different scenarios for pseudoarthrosis in the adult spine deformity patient and the preferred treatment method to obtain the best outcome for every individual patient. These slides can be retrieved under Electronic Supplementary Material.