Editorial: Stabilization of the sacroiliac joint

Lower back pain and pain involving the area of the posterior iliac spine are extremely common. Degeneration of the sacroiliac joint (SIJ) is one potential cause for lower back pain and pain radiating into the groin or buttocks. Degenerative changes to the lumbar spine and sacroiliac joints are common. A recent study evaluating SIJ abnormalities in a primary low back pain population demonstrated 31.7% of patients demonstrated SI joint abnormalities.4 As is the case for the evaluation and management of isolated lower back pain, the evaluation, management, and role for surgical intervention in SIJ pain is very controversial.

Many patients have degenerative changes of the disc, facet joints, and SIJs. A recent systematic review performed to determine the diagnostic accuracy of tests available to clinicians to identify the disc, facet joint, or SIJ as the source of low back pain concluded that tests do exist that change the probability of the disc or SIJ (but not the facet joint) as the source of low back pain.3 It was also concluded that the usefulness of these tests in clinical practice, particularly for guiding treatment selection, remains unclear.3

Although there is general agreement that SIJ pathological changes are a potential cause of pain, there is far less agreement about the optimal management of these conditions. A variety of conditions can cause SIJ dysfunction including degenerative and inflammatory arthritis, trauma, prior lumbosacral fusion, hip arthritis, limb length inequality, infections, and neoplasia.8 There is increasing evidence that image intensifier-guided single periarticular injection can correctly localize pain to the SIJ but the optimal management strategy remains controversial. Recent publications have compared surgical versus injection treatments and fusion versus denervation procedures.1,8 A systematic review found improvement regardless of the treatment, with most studies reporting over 40% improvement in pain as measured by VAS or NRS scores.8 It cautioned that one of the studies reported 17.6% of patients experiencing mild/no pain compared with 82.4% experiencing marked/severe pain at 39 months after SIJ fusion procedures.6,8 This systematic review also noted that despite improvements in reported pain, less than half of patients who had work status reported as returning to work.8

Because of the functional and socioeconomic consequences of chronic lower back pain, numerous surgical treatments to improve this condition have been attempted by spinal surgeons through the years. Arthrodesis of the SIJ is a surgical procedure with a long history dating to the beginnings of spinal surgery.7 Poor results, high complication rates and the need for additional surgical procedures have generally diminished the enthusiasm for this procedure until recently.6

A variety of “minimally invasive” procedures have been recently introduced that have rekindled enthusiasm for the surgical management of SIJ pathology. The technique demonstrated in the “Stabilization of the SIJ with SI-Bone” is one of these new techniques. There has been a recent publication detailing the very short term clinical outcomes with this technique that reported encouraging results.5 In this series of 50 patients, quality of life questionnaires were available for 49 patients preoperatively, 41 patients at 3 months, 40 at 6 months and only 27 at 12 months, complicating the ability to accurately assess true outcomes.

Although the focus of this video by Geisler is on the surgical technique, there should have been more information provided on the expected surgical outcomes and potential complications of SIJ fusion.2 The video only gives minimal information on how to appropriately select patients with potential SIJ pathology for surgical intervention. There are insufficient recommendations on the clinical and radiographic follow-up needed for this procedure. A concern with this implant is whether the porous plasma spray coating on the implant actually results in bone growth across the SIJ or only serves as a stabilizer. If true fusion does not result, deterioration in the clinical result could occur over time.

This video nicely demonstrates the surgical technique of stabilization of the SIJ with SI-Bone product. There are numerous unanswered questions regarding patient selection for SIJ fusion or stabilization. There are an increasing number of surgical techniques for treating SIJ pathology and it is not clear which method may provide the best outcomes. Without prospective trials with nonconflicted surgeons and standardized selection criteria, the true role for SIJ fusion procedures in the management of chronic lower back pain will remain murky. The consequences of the unsupported enthusiasm for the surgical management of discogenic back pain still negatively impacts the public perception of spinal surgeons. Much more high quality information is needed regarding the surgical management of SIJ pathology before widespread use of this technique should be adopted.

Cervical spine alignment, sagittal deformity, and clinical implications: a review

This paper is a narrative review of normal cervical alignment, methods for quantifying alignment, and how alignment is associated with cervical deformity, myelopathy, and adjacent-segment disease (ASD), with discussions of health-related quality of life (HRQOL). Popular methods currently used to quantify cervical alignment are discussed including cervical lordosis, sagittal vertical axis, and horizontal gaze with the chin-brow to vertical angle. Cervical deformity is examined in detail as deformities localized to the cervical spine affect, and are affected by, other parameters of the spine in preserving global sagittal alignment. An evolving trend is defining cervical sagittal alignment. Evidence from a few recent studies suggests correlations between radiographic parameters in the cervical spine and HRQOL. Analysis of the cervical regional alignment with respect to overall spinal pelvic alignment is critical. The article details mechanisms by which cervical kyphotic deformity potentially leads to ASD and discusses previous studies that suggest how postoperative sagittal malalignment may promote ASD. Further clinical studies are needed to explore the relationship of cervical malalignment and the development of ASD. Sagittal alignment of the cervical spine may play a substantial role in the development of cervical myelopathy as cervical deformity can lead to spinal cord compression and cord tension. Surgical correction of cervical myelopathy should always take into consideration cervical sagittal alignment, as decompression alone may not decrease cord tension induced by kyphosis. Awareness of the development of postlaminectomy kyphosis is critical as it relates to cervical myelopathy. The future direction of cervical deformity correction should include a comprehensive approach in assessing global cervicalpelvic relationships. Just as understanding pelvic incidence as it relates to lumbar lordosis was crucial in building our knowledge of thoracolumbar deformities, T-1 incidence and cervical sagittal balance can further our understanding of cervical deformities. Other important parameters that account for the cervical-pelvic relationship are surveyed in detail, and it is recognized that all such parameters need to be validated in studies that correlate HRQOL outcomes following cervical deformity correction.

Multiple human papillomavirus infections and HIV seropositivity as risk factors for abnormal cervical cytology among female sex workers in Nairobi

We estimated type-specific prevalence of human papillomavirus (HPV) and examined risk factors for abnormal cervical cytology among 296 female sex workers from Nairobi, Kenya. Over half (54%) were infected with a high-risk (HR) HPV type, of which HPV16 and 52 were the most common types. HIV-1 prevalence was 23% and HIV-1 sero-positivity was associated with high-grade cervical lesions, particularly among women with CD4 count less than 500 cells/mm(3) (odds ratio [OR] = 6.9; 95% confidence interval [CI]: 1.7-24.9). Among women who had normal cytology at the time of entry into the study, the risk of having an abnormal Pap smear within one year was significantly elevated for women with multiple HPV types at study entry (adjusted odds ratio [aOR] = 6.0; 95% CI: 2.3-15.7) and with a subset of HR HPV types (aOR = 4.2; 95% CI: 1.6-11.2). Detection of multiple concurrent HPV infections may be a useful marker to identify women at risk of developing precancerous lesions in populations of high HPV prevalence.

Assessment of Morbidity and Mortality Collection Data 2009

STUDY DESIGN

A retrospective analysis of the morbidity and mortality data collected by the SRS in 2009 with comparison to previous years.

OBJECTIVES

Objective of this study was to assess the new format of morbidity and mortality data collection by the SRS in 2009 and evaluate the data collected with comparison to previous years.

SUMMARY OF BACKGROUND DATA

2009 morbidity and mortality reporting format was dramatically changed from previous years. This was done in an attempt to simplify the reporting process and to narrow the reporting to only three sentinel events: death, blindness, and neurologic injury. Only deformity cases including scoliosis, kyphosis, and Grade III or greater spondylolisthesis were included.

METHODS

Results were obtained from the SRS M & M reporting summary for 2009. These included detailed analysis for complications including death, blindness, and neurologic injury. These were compared to similar statistics obtained from the years dating back to 2001. Blindness has not previously been reported.

RESULTS

80.1% of SRS members submitted 35,267 deformity cases. Both the percentage of members submitting data and the number of deformity cases far exceeded any previous year total. 57.6% of cases involved scoliosis, 10.5% kyphosis, and 31.9% spondylolisthesis. Neurologic complications were lower in each major category (scoliosis, kyphosis, and spondylolisthesis) compared to previous years. The death rate was similar to prior reporting 0.12%. Three cases of blindness were reported, two occurred in AIS. All three resolved.

CONCLUSIONS

The altered format and requirement for all members to participate has dramatically increased the total number of deformity cases reported and percent of membership responding. Neurologic injury rates are decreased from previous years. Three cases of blindness occurred, all of which resolved. Further collection of data is needed to elucidate mechanism and prevention.

Coronal realignment and reduction techniques and complication avoidance

Scoliosis is a broad term encompassing multiple pathologies with different etiologies. Patients may range from the infant with congenital deformity, to the adolescent with idiopathic scoliosis, to the elderly patient with severe degenerative scoliosis. Treatment must be tailored to individual circumstances and the pathoanatomy of each deformity. Various coronal reduction techniques have been described and will be discussed within this article. While scoliosis is generally considered a deformity in the coronal plane, often deformity is present in the sagittal and axial planes also. Treatment of these deformities can require osteotomies or vertebral column resections, techniques further discussed in accompanying articles.

Ab Initio electronic properties of monolayer phosphorus nanowires in silicon

Epitaxial circuitry offers a revolution in silicon technology, with components that can be fabricated on atomic scales. We perform the first ab initio calculation of atomically thin epitaxial nanowires in silicon, investigating the fundamental electronic properties of wires two P atoms thick, similar to those produced this year by Weber et al. For the first time, we catch a glimpse of disorder-related effects in the wires--a prerequisite for understanding real fabricated systems. Interwire interactions are made negligible by including 40 ML of silicon in the vertical direction (and the equivalent horizontally). Accurate pictures of band splittings and the electronic density are presented, and for the first time the effective masses of electrons in such device components are calculated.

Assessment of symptomatic rod fracture after posterior instrumented fusion for adult spinal deformity

BACKGROUND

Improved understanding of rod fracture (RF) in adult spinal deformity could be valuable for implant design, surgical planning, and patient counseling.

OBJECTIVE

To evaluate symptomatic RF after posterior instrumented fusion for adult spinal deformity.

METHODS

A multicenter, retrospective review of RF in adult spinal deformity was performed. Inclusion criteria were spinal deformity, age older than 18 years, and more than 5 levels posterior instrumented fusion. Rod failures were divided into early (≤12 months) and late (>12 months).

RESULTS

Of 442 patients, 6.8% had symptomatic RF. RF rates were 8.6% for titanium alloy, 7.4% for stainless steel, and 2.7% for cobalt chromium. RF incidence after pedicle subtraction osteotomy (PSO) was 15.8%. Among patients with a PSO and RF, 89% had RF at or adjacent to the PSO. Mean time to early RF (63%) was 6.4 months (range, 2-12 months). Mean time to late RF (37%) was 31.8 months (range, 14-73 months). The majority of RFs after PSO (71%) were early (mean, 10 months). Among RF cases, mean sagittal vertical axis improved from preoperative (163 mm) to postoperative (76.9 mm) measures (P<.001); however, 16 had postoperative malalignment (sagittal vertical axis>50 mm; mean, 109 mm).

CONCLUSION

Symptomatic RF occurred in 6.8% of adult spinal deformity cases and in 15.8% of PSO patients. The rate of RF was lower with cobalt chromium than with titanium alloy or stainless steel. Early failure was most common after PSO and favored the PSO site, suggesting that RF may be caused by stress at the PSO site. Postoperative sagittal malalignment may increase the risk of RF.

Clinical and radiographic evaluation of the adult spinal deformity patient

Among the prevalent forms of adult spinal deformity are residual adolescent idiopathic and degenerative scoliosis, kyphotic deformity, and spondylolisthesis. Clinical evaluation should include a thorough history, discussion of concerns, and a review of comorbidities. Physical examination should include assessment of the deformity and a neurologic examination. Imaging studies should include full-length standing posteroanterior and lateral spine radiographs, and measurement of pelvic parameters. Advanced imaging studies are frequently indicated to assess for neurologic compromise and for surgical planning. This article focuses on clinical and radiographic evaluation of spinal deformity in the adult population, particularly scoliosis and kyphotic deformities.

Management of high-grade spondylolisthesis

Management of high-grade spondylolisthesis (HGS) remains challenging and is associated with significant controversies. The best surgical procedure remains debatable. Although the need for instrumentation is generally agreed upon, significant controversies still surround the role of reduction and anterior column support in the surgical management of HGS. Complications with operative management of HGS can be significant and often dictate the selection of surgical approach. This review highlights the pathophysiology, classification, clinical presentation, and management controversies of HGS, in light of recent advances in our understanding of the importance of sagittal spinopelvic alignment and technologic advancements.

Dorsal thoracic arachnoid web and the "scalpel sign": a distinct clinical-radiologic entity

Arachnoid webs are intradural extramedullary bands of arachnoid tissue that can extend to the pial surface of the spinal cord, causing a focal dorsal indentation of the cord. These webs tend to occur in the upper thoracic spine and may produce a characteristic deformity of the cord that we term the "scalpel sign." We describe 14 patients whose imaging studies demonstrated the scalpel sign. Ten of 13 patients who underwent MR imaging demonstrated T2WI cord signal-intensity changes, and 7 of these patients also demonstrated syringomyelia adjacent to the level of indentation. Seven patients underwent surgery, with 5 demonstrating an arachnoid web as the cause of the dorsal indentation demonstrated on preoperative imaging. Although the webs themselves are rarely demonstrated on imaging, we propose that the scalpel sign is a reliable indicator of their presence and should prompt consideration of surgical lysis, which is potentially curative.

Effect of Severity of Rod Contour on Posterior Rod Failure in the Setting of Lumbar Pedicle Subtraction Osteotomy (PSO)

BACKGROUND:

Rod failure has been reported clinically in pedicle subtraction osteotomy (PSO) to correct flat back deformity.

OBJECTIVE:

To characterize the fatigue life of posterior screw-rod constructs in the setting of PSO as a function of the severity of rod contour angle.

METHODS:

A modified ASTM F1717 to 04 was used. Rods were contoured to the appropriate angle for the equivalent 20-, 40-, or 60-degree PSO angles. Testing was performed on a mechanical test frame at 400/40 N and 250/25 N, and specimens were cycled at 4 Hz to failure or run-out at 2 000 000 cycles. The effect of the screw-rod system on fatigue strength of curved rods was compared using Cox proportional hazards regression.

RESULTS:

At 400 N/40 N, Cox proportional hazards regression indicated that contouring rods from a 20-degree PSO angle to either 40 or 60 degrees significantly decreased fatigue life (hazard ratio = 7863.6, P = .0144). However, contouring rods from a 40-degree PSO angle to 60 degrees had no significant effect on the fatigue life (P &gt; .05). At 250 N/25 N, Cox proportional hazards regression indicated that contouring rods from a 20-degree PSO angle to either 40 or 60 degrees significantly decreased fatigue life (hazard ratio = 7863.6, P = .0144). Furthermore, contouring rods from a 40-degree PSO angle to 60 degrees had a significant effect on the fatigue life (hazard ratio = 7863.6, P = .0144).

CONCLUSION:

Results suggest that in the setting of PSO, the fatigue life of posterior spinal fixation rods depends largely on the severity of the rod angle used to maintain the vertebral angle created by the PSO and is significantly lowered by rod contouring.

Short-term complications associated with surgery for high-grade spondylolisthesis in adults and pediatric patients: a report from the scoliosis research society morbidity and mortality database

BACKGROUND

Although it is generally agreed upon that surgery for high-grade spondylolisthesis (HGS) is associated with more complications than low-grade spondylolisthesis, its description is primarily based on case reports and relatively small case series.

OBJECTIVE

To assess short-term complication rates associated with the surgical treatment of HGS in pediatric and adult patients and to identify factors associated with increased complication rates.

METHODS

All cases of HGS from the Scoliosis Research Society Morbidity and Mortality database for the year 2007 were reviewed. Patients were classified as pediatric (≤18 years) or adult (>18 years). Complications were tabulated, and the rates were compared between the patient groups and based on clinical and surgical factors.

RESULTS

165 cases of HGS were reported (88 pediatric, 77 adult). There were 49 complications (29.7%) in 41 patients (24.8%), with no difference in the proportions of pediatric vs adult patients with a complication (P = .86). Occurrence of new neurological deficit after surgery was the most common complication, seen in 19 (11.5%) patients. Performance of an osteotomy was associated with a higher incidence of new neurological deficits in both adult and pediatric groups (P = .02 and P = .012, respectively). Although most of the new neurological deficits improved over follow-up, 10% had no improvement.

CONCLUSION

This study provides short-term complication rates associated with surgical treatment for HGS in adult and pediatric patients and may prove valuable for patient counseling, surgical planning, and in efforts to improve the safety of patient care.

Clinical and radiographic parameters that distinguish between the best and worst outcomes of scoliosis surgery for adults

PURPOSE

Predictors of marked improvement versus failure to improve following surgery for adult scoliosis have not been identified. Our objective was to identify factors that distinguish between patients with the best and worst outcomes following surgery for adult scoliosis.

METHODS

This is a secondary analysis of a prospective, multicenter spinal deformity database. Inclusion criteria included: age 18-85, scoliosis (Cobb ≥ 30°), and 2-year follow-up. Based on the Oswestry Disability Index (ODI) and the SRS-22 at 2-year follow-up, patients with the best and worst outcomes were identified for younger (18-45) and older (46-85) adults with scoliosis. Clinical and radiographic factors were compared between patients with the best and worst outcomes.

RESULTS

276 patients met inclusion criteria (89 younger and 187 older patients). Among younger patients, predictors of poor outcome included: depression/anxiety, smoking, narcotic medication use, older age, greater body mass index (BMI) and greater severity of pain prior to surgery. Among older patients, predictors of poor outcome included: depression/anxiety, narcotic medication use, greater BMI and greater severity of pain prior to surgery. None of the other baseline or peri-operative factors assessed distinguished the best and worst outcomes for younger or older patients, including severity of deformity, operative parameters, or the occurrence of complications.

CONCLUSIONS

Not all patients achieve favorable outcomes following surgery for adult scoliosis. Baseline and peri-operative factors distinguishing between patients with the best and worst outcomes were predominantly patient factors, including BMI, depression/anxiety, smoking, and pain severity; not comorbidities, severity of deformity, operative parameters, or complications.

Frequency, risk factors, and treatment of distal adjacent segment pathology after long thoracolumbar fusion: a systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

To systematically review the literature related to distal adjacent segment pathology (ASP) after long thoracolumbar fusions for deformity including frequency, risk factors, frequency differences between adolescents and adults, surgical approach for revision, and revision complications.

SUMMARY OF BACKGROUND DATA

Spinal deformity surgery complications include ASP. Although ASP at the rostral end of instrumented fusions has been well described, substantially less has been documented about distal ASP.

METHODS

A systematic search was conducted in Medline and the Cochrane Collaboration Library for articles published between January 1, 1983, and March 15, 2012. We included all articles that described distal ASP after long thoracolumbar fusion for deformity. Radiographical ASP (RASP) was defined as evidence of ASP based on imaging, and clinical ASP (CASP) was defined as symptomatic ASP.

RESULTS

Seven retrospective cohort studies met inclusion criteria. Distal CASP developed in 17.7% at 2- 6-year follow-up and 19.8% at 9-year follow-up, whereas reoperation due to CASP was reported in 15.6% at 2 to 6 years and 14.4% at 9 years. Distal RASP was more frequent (44.7%-65.5%). Preoperative sagittal imbalance was associated with increased risk of distal ASP. There was increased risk of CASP in patients with higher postoperative fractional curve and increased risk of RASP in younger patients and those with preoperative disc degeneration, longer fusions, circumferential procedures, and postoperative L5-S1 disc space narrowing. No studies meeting inclusion criteria compared distal ASP in adults and adolescents or defined the best approach or complications for distal ASP revision.

CONCLUSION

Low-quality evidence suggests a cumulative rate of 18% to 20% for CASP and 45% to 65% for RASP after long thoracolumbar fusion for spinal deformity during 9-year follow-up. Low-quality evidence suggests an association between preoperative sagittal imbalance and distal ASP, with greater risk of distal ASP in patients with sagittal imbalance. Low-quality evidence suggests increased risk of CASP in patients with higher postoperative fractional curve and increased risk of RASP in younger patients and those with preoperative disc degeneration, longer fusions, circumferential procedures, and postoperative L5-S1 disc space narrowing.

CONSENSUS STATEMENT

1. The risk of developing new symptoms secondary to distal adjacent segment pathology following long thoracolumbar fusion for deformity is approximately 18–20% during a period of 9 years follow up, and most of these patients will require revision surgery. Strength of Statement: Weak. 2. The risk of developing distal adjacent segment pathology may be higher in those with preoperative sagittal imbalance, preoperative disc degeneration, longer fusions, circumferential procedures, and postoperative L5–S1 disc space narrowing. Strength of Statement: Weak.

Spontaneous improvement of cervical alignment after correction of global sagittal balance following pedicle subtraction osteotomy

Object

Sagittal spinopelvic malalignment is a significant cause of pain and disability in patients with adult spinal deformity. Surgical correction of spinopelvic malalignment can result in compensatory changes in spinal alignment outside of the fused spinal segments. These compensatory changes, termed reciprocal changes, have been defined for thoracic and lumbar regions but not for the cervical spine. The object of this study was to evaluate postoperative reciprocal changes within the cervical spine following lumbar pedicle subtraction osteotomy (PSO).

Methods

This was a multicenter retrospective radiographic analysis of patients from International Spine Study Group centers. Inclusion criteria were as follows: adults (>18 years old) with spinal deformity treated using lumbar PSO, a preoperative C7–S1 plumb line greater than 5 cm, and availability of pre- and postoperative full-length standing radiographs.

Results

Seventy-five patients (60 women, mean age 59 years) were included. The lumbar PSO significantly improved sagittal alignment, including the C7–S1 plumb line, C7–T12 inclination, and pelvic tilt (p <0.001). After lumbar PSO, reciprocal changes were seen to occur in C2–7 cervical lordosis (from 30.8° to 21.6°, p <0.001), C2–7 plumb line (from 27.0 mm to 22.9 mm), and T-1 slope (from −38.9° to −30.4°, p <0.001). Ideal correction of sagittal malalignment (postoperative sagittal vertical alignment < 50 mm) was associated with the greatest relaxation of cervical hyperlordosis (−12.4° vs −5.7°, p = 0.037). A change in cervical lordosis correlated with changes in T-1 slope (r = −0.621, p <0.001), C7–T12 inclination (r = 0.418, p <0.001), T12–S1 angle (r = −0.339, p = 0.005), and C7–S1 plumb line (r = 0.289, p = 0.018). Radiographic parameters that correlated with changes in cervical lordosis on multivariate linear regression analysis included change in T-1 slope and change in C2–7 plumb line (r2 = 0.53, p <0.001).

Conclusions

Adults with positive sagittal spinopelvic malalignment compensate with abnormally increased cervical lordosis in an effort to maintain horizontal gaze. Surgical correction of sagittal malalignment results in improvement of the abnormal cervical hyperlordosis through reciprocal changes.

Cervical spinal cord bullet fragment removal using a minimally invasive surgical approach: a case report

INTRODUCTION

We present a case of penetrating gunshot injury to the high-cervical spinal cord and describe a minimally invasive approach used for removal of the bullet fragment. We present this report to demonstrate technical feasibility of a minimally invasive approach to projectile removal.

CASE PRESENTATION

An 18-year-old African-American man presented to our hospital with a penetrating gunshot injury to the high-cervical spine. The bullet lodged in the spinal cord at the C1 level and rendered our patient quadriplegic and dependent on a ventilator. For personal and forensic reasons, our patient and his family requested removal of the bullet fragment almost one year following the injury. Given the significant comorbidity associated with quadriplegia and ventilator dependency, a minimally invasive approach was used to limit the peri-operative complication risk and expedite recovery. Using a minimally invasive expandable retractor system and the aid of a microscope, the posterior arch of C1 was removed, the dura was opened, and the bullet fragment was successfully removed from the spinal cord.

CONCLUSIONS

Here we describe a minimally invasive procedure demonstrating the technical feasibility of removing an intramedullary foreign object from the high-cervical spine. We do not suggest that the availability of minimally invasive procedures should lower the threshold or expand the indications for the removal of bullet fragments in the spinal canal. Rather, our objective is to expand the indications for minimally invasive procedures in an effort to reduce the morbidity and mortality associated with spinal procedures. In addition, this report may help to highlight the feasibility of this approach.

Does prior short-segment surgery for adult scoliosis impact perioperative complication rates and clinical outcome among patients undergoing scoliosis correction?

Object

In many adults with scoliosis, symptoms can be principally referable to focal pathology and can be addressed with short-segment procedures, such as decompression with or without fusion. A number of patients subsequently require more extensive scoliosis correction. However, there is a paucity of data on the impact of prior short-segment surgeries on the outcome of subsequent major scoliosis correction, which could be useful in preoperative counseling and surgical decision making. The authors' objective was to assess whether prior focal decompression or short-segment fusion of a limited portion of a larger spinal deformity impacts surgical parameters and clinical outcomes in patients who subsequently require more extensive scoliosis correction surgery.

Methods

The authors conducted a retrospective cohort analysis with propensity scoring, based on a prospective multicenter deformity database. Study inclusion criteria included a patient age ≥ 21 years, a primary diagnosis of untreated adult idiopathic or degenerative scoliosis with a Cobb angle ≥ 20°, and available clinical outcome measures at a minimum of 2 years after scoliosis surgery. Patients with prior short-segment surgery (< 5 levels) were propensity matched to patients with no prior surgery based on patient age, Oswestry Disability Index (ODI), Cobb angle, and sagittal vertical axis.

Results

Thirty matched pairs were identified. Among those patients who had undergone previous spine surgery, 30% received instrumentation, 40% underwent arthrodesis, and the mean number of operated levels was 2.4 ± 0.9 (mean ± SD). As compared with patients with no history of spine surgery, those who did have a history of prior spine surgery trended toward greater blood loss and an increased number of instrumented levels and did not differ significantly in terms of complication rates, duration of surgery, or clinical outcome based on the ODI, Scoliosis Research Society-22r, or 12-Item Short Form Health Survey Physical Component Score (p > 0.05).

Conclusions

Patients with adult scoliosis and a history of short-segment spine surgery who later undergo more extensive scoliosis correction do not appear to have significantly different complication rates or clinical improvements as compared with patients who have not had prior short-segment surgical procedures. These findings should serve as a basis for future prospective study.