The effect of prophylactic vertebroplasty on the incidence of proximal junctional kyphosis and proximal junctional failure following posterior spinal fusion in adult spinal deformity: a 5-year follow-up study

Background Context

The incidence of proximal junctional kyphosis (PJK) ranges from 5% to 46% following adult spinal deformity surgery. Approximately 66% to 76% of PJK occurs within 3 months of surgery. A subset of these patients, reportedly 26% to 47%, develop proximal junctional failure (PJF) within 6 months postoperatively. To date, there are no studies evaluating the impact of prophylactic vertebroplasty on PJK and PJF incidence at long-term follow-up.

Prophylactic vertebral cement augmentation at the uppermost instrumented vertebra and rostral adjacent vertebra for the prevention of proximal junctional kyphosis and failure following long-segment fusion for adult spinal deformity

Background Context

Proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) are common problems after long-segment (>5 levels) thoracolumbar instrumented fusions in the treatment of adult spinal deformity (ASD). No specific surgical strategy has definitively been shown to lower the risk of PJK as the result of a multifactorial etiology.

Poor visualization limits diagnosis of proximal junctional kyphosis in adolescent idiopathic scoliosis

Background Context

Multiple methods are used to measure proximal junctional angle (PJA) and diagnose proximal junctional kyphosis (PJK) after fusion for adolescent idiopathic scoliosis (AIS); however, there is no gold standard. Previous studies using the three most common measurement methods, upper-instrumented vertebra (UIV)+1, UIV+2, and UIV to T2, have minimized the difficulty in obtaining these measurements, and often exclude patients for which measurements cannot be recorded.

Proximal junctional kyphosis following adult spinal deformity surgery

Purpose

Proximal junctional kyphosis (PJK) is a common radiographic finding following long spinal fusions. Whether PJK leads to negative clinical outcome is currently debatable. A systematic review was performed to assess the prevalence, risk factors, and treatments of PJK.

Methods

Literature search was conducted on PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials using the terms ‘proximal junctional kyphosis’ and ‘proximal junctional failure’. Excluding reviews, commentaries, and case reports, we analyzed 33 studies that reported the prevalence rate, risk factors, and discussions on PJK following spinal deformity surgery.

Results

The prevalence rates varied widely from 6 to 61.7 %. Numerous studies reported that clinical outcomes for patients with PJK were not significantly different from those without, except in one recent study in which adult patients with PJK experienced more pain. Risk factors for PJK included age at operation, low bone mineral density, shorter fusion constructs, upper instrumented vertebrae below L2, and inadequate restoration of global sagittal balance.

Conclusions

Prevalence of PJK following long spinal fusion for adult spinal deformity was high but not clinically significant. Careful and detailed preoperative planning and surgical execution may reduce PJK in adult spinal deformity patients.     

Proximal junctional kyphosis following correction surgery in the Lenke 5 adolescent idiopathic scoliosis patient

Background

To investigate the risk factors of proximal junctional kyphosis (PJK) in Lenke 5 AIS patients after all-pedicle instrumentation and correction, and to compare the difference of radiographic and clinical outcome between PJK and Non-PJK populations.

Rod stiffness as a risk factor of proximal junctional kyphosis after adult spinal deformity surgery: comparative study between cobalt chrome multiple-rod constructs and titanium alloy two-rod constructs

Background Context

Little is known about the effect of rod stiffness as a risk factor of proximal junctional kyphosis (PJK) after adult spinal deformity (ASD) surgery.

Proximal junctional kyphosis in adult scoliosis: comparison of four radiological predictor models

Objective

The objective of this retrospective study is to identify the best immediate postoperative radiological predictors for the occurrence of proximal junctional kyphosis (PJK). Four proposed methods will be explored.

Methods

A homogeneous database of adult scoliosis from multiple centers was used. Patients with whole spine X-rays at the required follow-up (FU) periods were included. Spinal and pelvic parameters were measured and calculated to compare four predictive methods: Method 1: assessment of the global sagittal alignment (GSA); Method 2: restoration of the theoretical values of lumbar lordosis (LL) and thoracic kyphosis (TK) according to pelvic incidence (PI); Method 3: evaluation of TK + LL, and Method 4: restoration of the apex of sagittal LL to its theoretical values according to various spine shapes in Roussouly Classification. PJK occurrence was assessed at the last FU radiograph.

Results

250 patients were included; mean age was 56.67 years and mean FU was 2.5 years. PJK occurred in 25.6% of cases. PJK occurred in 19.9% in patients with a GSA <45° and in 29.9% where GSA >45° (p = 0.04, OR = 1.71). Restoring the sagittal apex of the LL to its theoretical values according to PI deceased PJK to 13.5% compared to 38.9% in the other cases (p = 0.01, OR = 4.6). The two other described methods (2 and 3) were not significant predictors.

Discussion

The comparison between the four predictive methods showed that a GSA >45° and restoration of sagittal apex of lordosis according to PI, were the most predictive methods for PJK in ASD. The latter had a higher predictive value. Our findings could prove useful in effective preoperative planning in ASD surgery to reduce PJK rates.

Level of evidence

Level IV.

     

Five major controversial issues about fusion level selection in corrective surgery for adolescent idiopathic scoliosis: a narrative review

Background Context

Shoulder imbalance, coronal decompensation, and adding-on phenomenon following corrective surgery in patients with adolescent idiopathic scoliosis are known to be related to the fusion level selected. Although many studies have assessed the appropriate selection of the proximal and distal fusion level, no definite conclusions have been drawn thus far.

Osteotomies in proximal junctional kyphosis in the cervicothoracic area

Introduction

Proximal junctional kyphosis (PJK) of the cervicothoracic spine is a deformity that can affect patients who have undergone long thoracolumbar instrumented fusion. Preoperative hyperkyphosis of the thoracic spine and changes of more than 30° in lumbar lordosis are independent risk factors for the onset of PJK.

Methods

When PJK occurs in the cervicothoracic spine, extension of the fusion with eventual application of osteotomy techniques is frequently necessary to treat symptomatic patients or in case a neurological deficit occurs. Ponte osteotomy and pedicle subtraction osteotomy (PSO) are the two most used techniques to restore a good cervicothoracic alignment, although they are still demanding procedures even for expert surgeons. In junctional fractures, a vertebral column resection can be performed to support the anterior column. Ponte osteotomy ideally restores 10° at each treated level, while PSO allows a segmental correction up to 30°–35°. Adequate preoperative planning is fundamental for outlining the correct surgery and choosing the appropriate osteotomy.

Conclusions

The aim of corrective surgery is to restore the cervicothoracic alignment, obtaining an adequate postoperative sagittal balance and decreasing the risk of further complications and new revision surgeries.

     

Novel titanium constructs for chest wall reconstruction in children

Purpose

We have previously reported the use of the vertical expandable prosthetic titanium rib (VEPTR) for treatment of thoracic dystrophy. This report describes our experience with this device and other novel titanium constructs for chest wall reconstruction.

Methods

This is a retrospective chart review of all children and adolescents undergoing chest wall reconstruction with titanium constructs between December 2005 and May 2010.

Results

Six patients have undergone chest wall reconstruction with VEPTR or other titanium constructs. Four had chest wall resection for primary malignancy, 1 had metastatic chest wall tumor resection, and 1 had congenital chest wall deformity. There were no immediate complications, and all patients have exhibited excellent respiratory function with no scoliosis.

Conclusions

Chest wall reconstruction after tumor resection or for primary chest wall deformities can be effectively accomplished with VEPTR and other customized titanium constructs. Goals should be durable protection of intrathoracic organs and preservation of thoracic volume and function throughout growth. Careful preoperative evaluation and patient-specific planning are important aspects of successful reconstruction.     

Effects of orthotopic liver transplantation in inbred rats on bone biomechanical properties

Aim

To determine the effects of orthotopic liver transplantation in inbred rats on the mechanical properties of bones at different anatomic sites.

Methods

The 24 rats that survived liver transplantation were paired with sham-operated rats of similar body weight. Six months after surgery, the lumbar vertebra, the proximal femur, and the middle femoral shaft were measured for their biomechanical properties and bone mineral density.

Results

The ultimate force, the ultimate stress, the Young modulus and the bone mineral density of both the proximal femur and the middle femur shaft of the rats were significantly reduced in the liver transplant group. However, no significant change was observed in the various parameters that indicate the biomechanical properties and the bone mineral density of the lumbar vertebra.

Conclusions

Orthotopic liver transplantation impairs the biomechanical properties of the proximal femur and the middle femoral shaft. Orthotopic liver transplantation itself is one of the risk factors for posttransplant fracture.     

Combined Anterior-Posterior Surgery is the Most Important Risk Factor for Developing Proximal Junctional Kyphosis in Idiopathic Scoliosis

Background  

Several studies have identified risk factors for proximal junctional kyphosis (PJK) after instrumentation for scoliosis, but the relative risks are unclear.     

The evaluation of short fusion in idiopathic scoliosis

Background:

Selective thoracic fusion in type II curve has been recommended by King et al. since 1983. They suggested that care must be taken to use the vertebra that is neutral and stable so that the lower level of fusion is centered over the sacrum. Since then there has been the trend to do shorter and selective fusion of the major curve. This study was conducted to find out whether short posterior pedicle instrumentation alone could provide efficient correction and maintain trunk balance comparing to the anterior instrumentation.

Materials and Methods:

A prospective study was conducted during 2005-2007 on 39 consecutive cases with idiopathic scoliosis cases King 2 and 3 (Lenke 1A, 1B), 5C and miscellaneous. Only the major curve was instrumented unless both curves were equally rigid and of the same magnitude. The level of fusion was planned as the end vertebra (EVB) to EVB fusion, although minor adjustment was modified by the surgeons intraoperatively. The most common fusion levels in major thoracic curves were T6–T12, whereas the most common fusion levels in the thoraco-lumbar curves were T10–L3. Fusion was performed from the posterior only approach and the implants utilized were uniformly plate and pedicle screw system. All the patients were followed at least 2 years till skeletal maturity. The correction of the curve were assessed according to type of curve (lenke IA, IB and 5), severity of curve (less than 450, 450-890 and more than 900), age at surgery (14 or less and 15 or more) and number of the segment involved in instrumentation (fusion level less than curve, fusion level as of the curve and fusion more than the curve)

Results:

The average long-term curve correction for the thoracic was 40.4% in Lenke 1A, 52.2% in Lenke 1B and 56.3% in Lenke 5. The factors associated with poorer outcome were younger age at surgery (<11 years or Risser 0), fusion at wrong levels (shorter than the measured end vertebra) and rigid curve identified by bending study. However, all patients had significant improved trunk balance and coronal hump at the final assessment at maturity. Two patients underwent late extension fusion because of junctional scoliosis.

Conclusions:

With modern instrumentations, the EVB of the major curve can be used at the end of the instrumentation in most cases of idiopathic scoliosis. In those cases with either severe trunk shift, younger than 11 years old, or extreme rigid curve, an extension of one or more levels might be safer. In particular situations, the concept of centering the lowest vertebra over the sacrum should be adopted.     

Sagittal balance and idiopathic scoliosis: does final sagittal alignment influence outcomes,degeneration rate or failure rate?

Introduction

In the last decade, spine surgeons have been impacted by the “sagittal plane analysis revolution”. Significant correlations have been found in adult spinal deformity (ASD) between sagittal lumbo-pelvic parameters and functional outcomes, but most of them do not apply in adolescent idiopathic scoliosis (AIS). Meanwhile, instrumentation and reduction strategies have considerably evolved. This paper aims to describe the preoperative sagittal alignment in AIS, and to report literature evidence regarding the influence of postoperative sagittal balance on complication rates, low back pain incidence and disc degeneration.

Methods

A bibliographic search in Medline and Google database from 1984 to May 2017 was performed. The keywords included ‘adolescent idiopathic scoliosis’, ‘adult scoliosis’, ‘sagittal alignment’, ‘proximal junctional kyphosis’, ‘distal junctional kyphosis’, ‘outcomes’, ‘low back pain’ and ‘complication’, used individually or in combination.

Results

Algorithms of sagittal balance analysis and treatment decision have been reported in ASD, but the clinical situation is very different in children. Sagittal alignment greatly varies in AIS among the various Lenke types. Most patients are clinically balanced before surgery, but the spinal harmony is altered, with overgrowth of the anterior column and global sagittal flattening (undersestimated in 2D). The exact role of pelvic incidence and whether or not patients also use pelvic compensation to maintain balance still require further clarification. The incidence of radiological junctional failures remains highly variable, depending on definitions, cohort size and follow-up. Preoperative hyperkyphosis seems to be a consistent and relevant risk factor. Current literature does not support the recent trend to save motion segments (selective fusion), and no significant association was found between the distal level of fusion and the incidence of low back pain. Postoperative sagittal alignment seems to be more important than LIV selection to avoid disc degeneration at mid-term follow-up.

Conclusion

It is clear now that sagittal alignment plays a major role in clinical outcomes and should not be neglected in AIS. Seven key guidelines that should be considered for each patient before surgery are reported (Table 2). Personalized planning using 3D technology is gaining popularity and might help in the future reducing complications.

     

Teriparatide improves volumetric bone mineral density and fine bone structure in the UIV+1 vertebra,and reduces bone failure type PJK after surgery for adult spinal deformity

Summary

We conducted a prospective comparative study of the effect of teriparatide therapy for preventing vertebral-failure-type PJK after reconstructive surgery for adult spinal deformity. Prophylactic teriparatide improved the volumetric bone mineral density and fine bone structure of the vertebra above the upper-instrumented vertebra and reduced the incidence of vertebral-failure-type PJK.

Introduction

Proximal junctional kyphosis (PJK) is a complication after corrective surgery for spinal deformity. This study sought to determine whether teriparatide (TP) is an effective prophylactic against PJK type 2 (vertebral fracture) in surgically treated patients with adult spinal deformity (ASD).

Methods

Forty-three patients who started TP therapy immediately after surgery and 33 patients who did not receive TP were enrolled in this prospective case series. These patients were female, over 50, surgically treated for ASD, and followed for at least 2 years. Preoperative and postoperative standing whole-spine X-rays and dual-energy X-ray absorptiometry scans, and multidetector CT images obtained before and 6 months after surgery were used to analyze the bone strength in the vertebra above the upper-instrumented vertebra (UIV+1).

Results

Mean age was 67.9 years. After 6 months of treatment, mean hip-bone mineral density (BMD) increased from 0.721 to 0.771 g/cm² in the TP group and decreased from 0.759 to 0.729 g/cm² in the control group. This percent BMD change between groups was significant (p?<?0.05). The volumetric BMD (326 to 366 mg/cm³) and bone mineral content (BMC) (553 to 622 mg) at UIV+1 were also significantly increased in TP group. The bone volume/tissue volume ratio increased from 46 to 54 % in the TP group, and the trabecular bone thickness and number increased by 14 and 5 %, respectively. At the 2-year follow-up, the PJK type 2 incidence was significantly lower in the TP group (4.6 %) than in the control group (15.2 %; p?=?.02).

Conclusions

Prophylactic TP treatment improved the volumetric BMD and fine bone structure at UIV+1 and reduced the PJK-type 2 incidence.

     

Current evidence on where to end a fusion within the thoracolumbar junction most preferably – A systematic literature review

Proximal junctional kyphosis (PJK) is one main complication in the surgical treatment of adult spinal deformities. Ending within the thoracolumbar junction (TLJ) should but cannot always be avoided to reduce the risk for PJK. With this systematic review we sought to define the most preferable vertebra within the TLJ to minimize the risk for PJK and establish recommendations based on our findings. We conducted a systematic literature review by scanning the MEDLINE database in accordance with the PRISMA criteria. All articles addressing primary long-distance dorsal thoracolumbar fusion of at least three segments to treat adult spinal deformities were included. 1385 articles were identified and three were included to this review. The first study showed significantly higher rates of PJK in patients where the construct was extended to T7 or higher when compared to an ending at T11 to L1. The second article stated that an expansion to the TLJ resulted in significantly less surgical revisions due to PJK reduction. On the other hand, the third article found that a fusion of the whole thoracic spine reduces the PJK incidence postoperatively. Even though the most favorable vertebra within the TLJ to avoid PJK best could not yet be determined, our study identifies several principles that represent the current state of evidence for surgical treatment of adult scoliosis. Proper preoperative decision making based on thorough analysis and interpretation of the patient's sagittal alignment parameters can improve the individual outcome critically.     

Sagittal spinopelvic changes after posterior spinal fusion in adolescent idiopathic scoliosis

PurposeThis article examines if longer posterior spinal fusions with instrumentation (PSFI) into the lumbar spine (L3/4) alter spinopelvic parameters compared with selective fusions to T12/L1/L2 in adolescent idiopathic scoliosis (AIS) patients.MethodsWe analysed radiographs of 84 AIS patients, 58 (69%) females and 26 (31%) males, who underwent PSFI at an mean age of 15 years ± 2.5 years, range 10 years to 21 years, between 1st January 2007 and 31st December 2014. Radiographic parameters were measured pre- and post-operatively at most recent follow-up (range 2 years to 8.2 years): pelvic incidence (PI), lumbar lordosis (LL, L1–S1 and L4–S1), sagittal vertical alignment (SVA), scoliosis angle and proximal junctional kyphosis (PJK). PI–LL was calculated. Data was analysed using t-tests or Wilcoxon rank-sum tests.ResultsIn total, 32 patients underwent a selective fusion with lowest instrumented vertebra (LIV) T12–L2, and 52 patients underwent a fusion with LIV L3–L4. In both groups, scoliosis angle was significantly corrected at follow-up (p < 0.005).Pre-operatively, both groups had similar LL (L1–S1) and PI–LL. Post-operatively, LL increased in the L3–4 fusion group (p < 0.005) but did not change in the selective fusion group (p = 0.116). This change in LL in the L3–4 fusion group affected the post-operative PI–LL (T12–L2 fusion -4.9° versus L3–4 fusion -13.6°, p = 0.002). No differences were seen in PI, SVA or LL L4–S1 between groups. Radiographic PJK occurred in seven of the L3–4 patients with and without PJK (noPJK –8.8° versus PJK –25.8°, p = 0.026).ConclusionsIn patients who underwent a fusion ending at L3 or L4, LL was increased. This altered the PI–LL relationship, and appeared to increase the risk of PJK.Level of evidenceIII     

A multiinstitutional review of central venous line complications: retained intravascular fragments

Background

There have been many reports of complications of central venous lines in children but limited discussion of the specific problem of retained intravascular fragments after attempted removal. We report on a series of 6 patients from 2 tertiary pediatric hospitals that had intravascular segments of long-term central venous lines that could not be removed and so were left in situ.

Methods

We conducted a retrospective multiinstitutional review of long-term central venous lines (Broviacs, Port-A-Caths, and Hickmans) removed in the operating room with a focused chart review and prospective follow-up of those patients that had a failed attempt at removal.

Results

A total of 299 central venous lines were removed with 6 patients identified as having fragments of lines left behind (2%). The lines had been in place for an average of 37 ± 12 months. The average follow-up period is now 5.4 ± 3.9 years; none of the patients have developed any symptoms, evidence of thrombus, infection, or catheter migration.

Conclusion

Given the 2% incidence rate, the issue of managing a stuck long-term central venous line will face most individuals who place these lines. We have demonstrated that simply ligating the catheter and leaving the fragment in place appears to be a safe option with minimal risk to the patient.     

Relationship between thoracic hypokyphosis, lumbar lordosis and sagittal pelvic parameters in adolescent idiopathic scoliosis

Purpose

Sagittal spine and pelvic alignment of adolescent idiopathic scoliosis (AIS) is poorly described in the literature. It generally reports the sagittal alignment with regard to the type of curve and never correlated to the thoracic kyphosis. The objective of this study is to investigate the relationship between thoracic kyphosis, lumbar lordosis and sagittal pelvic parameters in thoracic AIS.

Methods

Spinal and pelvic sagittal parameters were evaluated on lateral radiographs of 86 patients with thoracic AIS; patients were separated into hypokyphosis group (n = 42) and normokyphosis group (n = 44). Results were statistically analyzed. The lumbar lordosis was lower in the hypokyphosis group, due to the low proximal lordosis. The thoracic kyphosis was not correlated with any pelvic parameters but with the proximal lordosis. The pelvic incidence was correlated with sacral slope, pelvic tilt, lumbar lordosis and highly correlated with distal lumbar lordosis in the two groups. There was a significant linear regression between thoracic kyphosis and proximal lordosis and between pelvic incidence and distal lordosis.

Conclusions

We can consider that the proximal part of the lordosis depends on the thoracic kyphosis and the distal part depends on the pelvic incidence. The hypokyphosis in AIS is independent of the pelvic parameters and could be described as a structural parameter, characteristic of the scoliotic deformity.