Sakrumfraktur als seltene Frühkomplikation nach lumbosakraler Spondylodese

Treatment for sacral insufficiency fractures: A systematic review

Intro

Sacral insufficiency fractures after lumbosacral fusion continue to establish themselves as a rare complication after surgery. The diagnosis can often be missed due to inconclusive imaging and non-specific symptoms. In the literature, the treatment of sacral insufficiency fractures varies from non-operative and conservative management to surgical intervention with lumbopelvic fixation.

Methods

We performed a systematic review searching the PubMed database using sacral insufficiency fracture treatment after lumbosacral fusion and sacral insufficiency fracture after posterior spinal instrumentation as keywords.

Results

This search strategy identified 32 publications from the PubMed database for literature review. After evaluating the inclusion and exclusion criteria, a total of 17 articles were included in the review. 65% of sacral insufficiency fractures were managed surgically with 35% of patients proceeding with non-operative, conservative management only. Revision surgery always involved sacropelvic fixation which typically led to immediate resolution or reduction of symptoms, with the exception of 2 cases that did not receive adequate reduction of symptoms. Five cases reported failed non-operative management that subsequently responded to revision surgery.

Conclusion

Outcomes after non-operative management usually leads to symptom resolution; however has a slower symptom relief time as well as a higher chance of failed treatment. Operative outcomes, generally with a variation of sacropelvic fixation lead to immediate symptom resolution and very rarely failed treatment. Clinicians must always maintain a high index of suspicion of new onset lower back or sacral pain after lumbosacral surgery and order a CT scan to rule out a potential insufficiency fracture.

Objectives

The objective of this study was to review the literature to examine treatment options for sacral insufficiency fractures after lumbosacral fusion in order to improve clinical practice and management. This systematic review of the literature regarding treatment of sacral insufficiency fractures will assist clinicians in making the accurate diagnosis and devise a strategic treatment plan for patients with sacral insufficiency fractures after spinal instrumentation.

Sacral Insufficiency Fracture Following Short-Segment Lumbosacral Fusion: Case Series and Review of the Literature

STUDY DESIGN

Retrospective case series.

OBJECTIVE

Sacral insufficiency fracture is a rare and serious complication following lumbar spine instrumented fusion. The purpose of this study was to describe the patient characteristics, presentation, evaluation, treatment options, and outcomes for patients with sacral insufficiency fracture after short-segment lumbosacral fusion.

METHODS

Six patients from our institutional database and 16 patients from literature review were identified with a sacral insufficiency fracture after short-segment (L4-S1 or L5-S1) lumbar fusion within 1 year of surgery.

RESULTS

Patients were 55% female with a mean age of 58 years and body mass index of 30 kg/m². Osteoporosis or osteopenia was the most common comorbidity (85%). Half of patients sustained a sacral fracture after surgery from a posterior approach, while the others had anterior or anterior-posterior surgery. Mean time to fracture was 42 days with patients clinically presenting with new sacral pain (86%), radiculopathy (60%), or neurologic deficit (5%). Ultimately, 73% of patients underwent operative fixation often involving extension of the construct (75%) and fusion to the pelvis (69%). Men (P = .02) and patients with new radicular pain or neurologic deficit (P = .01) were more likely to undergo revision surgical treatment while women over 50 years of age were more likely to be treated conservatively (P = .003).

CONCLUSIONS

Spine surgeons should monitor for sacral insufficiency fracture as a source of new-onset pain in the postoperative period in patients with a short segment fusion to the sacrum. The recognition of this complication should prompt an assessment of bone health and management of underlying bone fragility.

Sacral insufficiency fractures after lumbosacral arthrodesis: salvage lumbopelvic fixation and a proposed management algorithm

OBJECTIVE

Sacral insufficiency fracture after lumbosacral (LS) arthrodesis is an uncommon complication. The objective of this study was to report the authors' operative experience managing this complication, review pertinent literature, and propose a treatment algorithm.

METHODS

The authors analyzed consecutive adult patients treated at their institution from 2009 to 2018. Patients who underwent surgery for sacral insufficiency fractures after posterior instrumented LS arthrodesis were included. PubMed was queried to identify relevant articles detailing management of this complication.

RESULTS

Nine patients with a minimum 6-month follow-up were included (mean age 73 ± 6 years, BMI 30 ± 6 kg/m2, 56% women, mean follow-up 35 months, range 8-96 months). Six patients had osteopenia/osteoporosis (mean dual energy x-ray absorptiometry hip T-score -1.6 ± 0.5) and 3 received treatment. Index LS arthrodesis was performed for spinal stenosis (n = 6), proximal junctional kyphosis (n = 2), degenerative scoliosis (n = 1), and high-grade spondylolisthesis (n = 1). Presenting symptoms of back/leg pain (n = 9) or lower extremity weakness (n = 3) most commonly occurred within 4 weeks of index LS arthrodesis, which prompted CT for fracture diagnosis at a mean of 6 weeks postoperatively. All sacral fractures were adjacent or involved S1 screws and traversed the spinal canal (Denis zone III). H-, U-, or T-type sacral fracture morphology was identified in 7 patients. Most fractures (n = 8) were Roy-Camille type II (anterior displacement with kyphosis). All patients underwent lumbopelvic fixation via a posterior-only approach; mean operative duration and blood loss were 3.3 hours and 850 ml, respectively. Bilateral dual iliac screws were utilized in 8 patients. Back/leg pain and weakness improved postoperatively. Mean sacral fracture anterolisthesis and kyphotic angulation improved (from 8 mm/11° to 4 mm/5°, respectively) and all fractures were healed on radiographic follow-up (mean duration 29 months, range 8-90 months). Two patients underwent revision for rod fractures at 1 and 2 years postoperatively. A literature review found 17 studies describing 87 cases; potential risk factors were osteoporosis, longer fusions, high pelvic incidence (PI), and postoperative PI-to-lumbar lordosis (LL) mismatch.

CONCLUSIONS

A high index of suspicion is needed to diagnose sacral insufficiency fracture after LS arthrodesis. A trial of conservative management is reasonable for select patients; potential surgical indications include refractory pain, neurological deficit, fracture nonunion with anterolisthesis or kyphotic angulation, L5-S1 pseudarthrosis, and spinopelvic malalignment. Lumbopelvic fixation with iliac screws may be effective salvage treatment to allow fracture healing and symptom improvement. High-risk patients may benefit from prophylactic lumbopelvic fixation at the time of index LS arthrodesis.

BMI and gender increase risk of sacral fractures after multilevel instrumented spinal fusion compared with bone mineral density and pelvic parameters

BACKGROUND CONTEXT

Sacral fractures are a rare but potentially devastating complication. Long-fusion constructs, including the sacrum, that do not extend to the pelvis may result in sacral fractures. Besides established risk factors including gender, age, and number of levels fused, body mass index (BMI), pelvic parameters, and bone mineral density (BMD) have also been proposed as potential risk factors for postoperative sacral fractures. The literature supporting this, however, is limited.

PURPOSE

The aim of the present study was to assess whether preoperative pelvic parameters, BMI, or BMD of patients with sacral fracture are different compared with age, gender, and fusion level-matched non-fracture controls.

STUDY DESIGN/SETTING

This is a case-control study.

PATIENT SAMPLE

Patients undergoing posterior instrumented fusion at a single academic institution between 2002 and 2016 were included in the study.

OUTCOME MEASURES

The outcome measure was occurrence of a postoperative sacral fracture.

METHODS

Patients with sacral fractures after posterior instrumented spinal fusion, including the sacrum, were retrospectively identified and matched 2:1 with non-fracture controls based on gender, age, and number of levels fused. Patients with concurrent spinopelvic fixation or missing preoperative computed tomography (CT) imaging were excluded. Preoperative sagittal balance was assessed using lateral radiographs. Quantitative computed tomography (QCT) assessment included standard measurements at L1/L2 and additional experimental measurements of the S1 body and sacral ala.

RESULTS

Twenty-one patients with sacral fracture were matched to non-fracture controls. The majority of the patients with sacral fracture was female (76.2%) and of advanced age (mean 66.4 years). Fracture and control groups were well matched with respect to gender, age, and number of levels fused. Standard measurements at L1/L2 showed no significant difference in BMD between the fracture and the control groups (109.9 mg/cm³ vs. 116.4 mg/cm³, p=.414). Similarly, there was no significant BMD differences between the groups using the experimental measurements of the S1 body (183.6 mg/cm³ vs. 176.2 mg/cm³, p=.567) and the sacral ala (8.9 mg/cm³ vs. 4.8 mg/cm³, p=.616). Mean preoperative pelvic incidence-lumbar lordosis mismatch and pelvic tilt were not significantly different between the groups. Univariate conditional logistic regression analysis revealed that the odds of experiencing a sacral fracture was approximately six times higher for obese patients compared with normal or underweight patients. After controlling for BMI in multivariate conditional logistic regression models, BMD was still not significantly associated with the odds of experiencing sacral fractures.

CONCLUSIONS

To our knowledge, this is the first study to assess the association of preoperative BMD measured by QCT, pelvic parameters, and BMI with postoperative sacral fractures in a large patient cohort. Interestingly, our data do not show any difference in preoperative pelvic parameters and BMD between the groups. This is in line with previous reports that indicate only a few patients with sacral fracture after fusion surgery have clear evidence of osteoporosis. Bone mineral density as a measure of bone quantity, rather than bone quality, may not be as important in these fractures as previously thought. Obesity, however, was associated with higher odds of experiencing postoperative sacral fractures. The present study thereby challenges the widespread concept that obesity is a protective factor against fractures in the elderly. In summary, our results suggest that BMI and gender, more than pelvic parameters and BMD, are risk factors for postoperative sacral fractures.

Sacral stress fracture after lumbar and lumbosacral fusion. How to manage it? A proposition based on three cases and literature review

Sacral fracture after lumbosacral instrumentation could be a source of prolonged pain and a late autonomy recovery in old patients. Diagnosis remains difficult and usually delayed. No clear consensus for efficient treatment of this complication has been defined. Aim of this study was to determine how to manage them. Three patients who sustained sacral fracture after instrumented lumbosacral fusion performed for degenerative disease of the spine are discussed. History, physical examinations' findings and radiographic features are presented. Pertinent literature was analyzed. All patients complained of unspecific low back and buttock pain a few weeks after index surgery. Diagnosis was done on CT-scan. We always choose revision surgery with good functional results. Sacral stress fracture has to be reminded behind unspecific buttock or low back pain. CT-scan seems to be the best radiological test to do the diagnosis. Surgical treatment is recommended when lumbar lordosis and pelvic incidence mismatched.

Incidence, diagnosis, and management of sacral fractures following multilevel spinal arthrodesis

BACKGROUND

Fractures of the sacrum are a rare complication following instrumented spinal fusion, with only 34 cases previously reported in the literature. Previous series have generally been limited to less than five cases.

PURPOSE

The purpose of this study is to determine the incidence of sacral fractures caudal to instrumented spinal fusion constructs, identify risk factors for fracture and for failure of conservative management, and describe strategies for surgical treatment of these fractures.

STUDY DESIGN

This is a retrospective review.

PATIENT SAMPLE

Patients undergoing instrumented posterior spinal arthrodesis between 2002 and 2011 were included in the sample.

OUTCOME MEASURES

Clinical and radiographic data from hospital and surgeon records comprise outcome measures.

METHODS

Methods include a review of clinical and radiographic data from a prospectively collected patient database recording all adjacent segment fractures during the study period.

RESULTS

Twenty-four patients developed sacral fractures caudal to instrumented spinal fusion constructs during the study period. The overall incidence was 6.1% and was significantly greater in fusions greater than four levels (14.5%). The mean time from index surgery to fracture was 4.3 months. Only one fracture was evident on plain radiography at the onset of symptoms. Computed tomography, magnetic resonance imaging, and nuclear scintigraphy can all be used to establish the diagnosis. Eight patients were successfully treated conservatively. The mean time to fracture union was 21 weeks. Anterolisthesis of the fracture greater than 2 mm and kyphotic angulation were significantly associated with failure of conservative management. Surgical intervention included posterior extension of the fusion construct to S2 and the iliac wings with sacroiliac joint fusion. In 10 cases, a combined anterior and posterior approach was used that consisted of either revision anterior lumbar interbody fusion or transsacral posterior lumbar interbody fusion.

CONCLUSIONS

Sacral fractures following instrumented posterior spinal fusion are an uncommon complication; that is often unrecognized on plain radiographs. Risk factors include osteoporosis and long spinal fusions. Anterolisthesis and kyphosis of the fracture is associated with failure of conservative management.

Sacral fractures complicating thoracolumbar fusion to the sacrum

STUDY DESIGN

Case series.

OBJECTIVE

To report on the rare complication of sacral fractures after long instrumented thoracolumbar fusions to the sacrum.

SUMMARY OF BACKGROUND DATA

Rigid spinal fusion with instrumentation results in redistribution of forces in the spine that can cause the adjacent segments to degenerate and fail. Rarely in long thoraco-lumbosacral fusion, these forces may lead to sacral fractures; only 4 cases are reported in the literature.

METHODS

Five patients with sacral fractures are presented; one had the fusion performed at a different institution. Patients' characteristics, radiographic findings, and final operative treatment are discussed.

RESULTS

Sagittal imbalance after the index operation (thoraco-lumbosacral fusion), osteoporosis, and obesity were potentially associated factors. Initial nonoperative treatment failed to improve patients' symptoms. Surgery was performed at an average of 3.25 months (range, 2-8 months) in 4 patients, and soon after presentation in the patient operated elsewhere (presented 18 months after the sacral fracture). The signs of failed L5-S1 fusion, present in 3 patients, were considered to be additional surgical indication. At surgery the posterior instrumentation was extended to the pelvis. Both the fracture and the failed anterior interbody fusion were addressed through an anterior approach in 4 cases and in one case with a posterior ascending titanium cage spanning from S2 to L5. Sagittal balance was restored only in the last patient, where at the time of the revision operation a pedicle subtraction osteotomy was performed. Pain resolved in all patients after surgery and to the latest follow-up (range, 6-36 months).

CONCLUSION

Relapse of low back or buttock pain and leg pain after thoracolumbar fusion to the sacrum may be related to a sacral fracture, difficult to diagnose in conventional radiographs. Surgery should be considered in the presence of a concomitant L5-S1 pseudarthrosis and when symptoms do not improve with the nonoperative treatment.

Sacral fractures after multi-segmental lumbosacral fusion: a series of four cases and systematic review of literature

Spine surgeons are becoming increasingly aware of sacral insufficiency fractures as a complication after lumbosacral fusions. We present four patients who suffered from sacral fractures after multi-segmental posterior lumbosacral fusion together with a systematic review of the literature that yielded six papers reporting on 12 cases. Summarizing these 16 cases, the typical patient suffering from this complication is a female, elderly individual [66.4 +/- 12.3 (mean +/- SD) years of age, 95% confidence interval 57.89-71] undergoing multilevel fusion of 4.9 +/- 3.4 (95% CI 3.1-6.8) segments. Due to nonspecific clinical complaints and inconclusive imaging there has been a median delay in diagnosis of 5 (IQR 3-6, range 1-49) weeks after onset of pain. It remains unclear whether this complication is rare or rather under-diagnosed. Fortunately, these fractures are predominantly benign conditions that respond well to conservative management in the majority of cases, depending on location.