Two-level pedicle subtraction osteotomy for severe thoracolumbar kyphotic deformity in ankylosing spondylitis

Study design

A retrospective clinical study.

Objective

To evaluate the outcomes of two-level (T12 and L3) pedicle subtraction osteotomy (PSO) for severe thoracolumbar kyphosis in ankylosing spondylitis (AS), and to discuss the surgical strategies of this surgery.

Background

Cases were limited on the results of two-level PSO for correction of severe kyphosis caused by AS, nor on surgical strategies of this type of surgery.

Methods

From March 2006 to December 2010, nine consecutive AS patients with severe kyphotic deformity, underwent T12 and L3 PSOs. Chin-brow vertical angle (CBVA) and radiographic assessments which contain thoracic kyphosis (TK), lumbar lordosis (LL), global kyphosis (GK), and sagittal vertical axis were carefully recorded pre and postoperatively to evaluate the sagittal balance. Intra and postoperative complications were also registered. All patients were asked to fill out Oswestry Disability Index before surgery and at the last follow-up visit.

Results

All nine patients (8M/1F), averaged 41.4 years old (range 35–51 years), were received two-level (T12 and L3) PSO, and were followed up after surgery for a mean of 39.9 months (range 24–68 months). Good cosmetic results were achieved in all patients. Mean correction at two-level PSO was 67.9 ± 5.5°. All CBVA, TK, LL, and GK were changed significantly after surgery (P < 0.05), the mean amount of correction of which were 59.5 ± 13.8, 34.7 ± 3.8, 33.2 ± 2.4, and 54.0 ± 14.8 degrees, respectively, and with a small loss of correction at the last follow-up visit. Sagittal imbalance was significantly improved from 27.3 ± 4.4 to 3.4 ± 0.7 cm postoperatively. Neither mortalities nor any major neurological complications were found. The mean ODI score was significantly improved from 53.4 ± 15.5 before surgery to 8.2 ± 4.7 at the last visit.

Conclusion

The outcomes of follow-up showed that two-level (T12 and L3) PSO can effectively and safely correct severe thoracolumbar kyphosis in AS.     

The use of posterior vertebral column resection in the management of severe posttuberculous kyphosis: a retrospective study and literature review

Purpose

We present a retrospective study of 15 cases with severe posttuberculous kyphosis of thoracolumbar region that underwent posterior vertebral column resection.

Methods

From 2004 to 2009, 15 consecutive patients with posttubercular kyphotic deformity underwent posterior vertebral resection osteotomy. Six subjects were females and nine were males with an average age of 35.8 years (range 20–60 years) at the time of surgery. None of the patients had neurological deficits. The mean preoperative visual analogue scale was 8.7 (range 3–9), and the average preoperative Oswestry Disability Index was 46.5 (range 40–56).

Results

The average duration of postoperative follow-up was 36.1 ± 10.7 months (range 24–62 months). The number of vertebra resected was 1.3 (range 1–2) on average. There were ten patients with one-level osteotomy and five patients with two-level osteotomy. The average operation time was 446.0 ± 92.5 min (range 300–640 min) with an average blood loss of 1,653.3 ± 777.9 ml (range 800–3000 ml). The focal kyphosis before surgery averaged 92.3 ± 8.9° (range 74–105°), and the kyphotic angle decreased to 34.5 ± 8.7° on average after the surgical correction. The average kyphotic angle at the last follow-up was 36.9 ± 8.5°, loss of correction was 2.4 ± 1.4° on average. All patients postoperatively received bony fusion within 6–9 months.

Conclusions

Our results showed that although posterior vertebral resection is a highly technical procedure, it can be used safely and effectively in the management of severe posttuberculous kyphosis. It is imperative that operations be performed by an experienced surgical team to prevent operation-related complications.     

Non-instrumented correction of cervicothoracic kyphosis in ankylosing spondylitis: a critical analysis on the results of open-wedge osteotomy C7-T1 with gradual Halo-Thoracic-Cast based correction

Introduction

With progression of cervicothoracic kyphosis (CTK), ankylosing spondylitis (AS) patients suffer functional disability. Surgical correction still poses neurologic risks, while evidence of an ideal technique preventing its complications is weak.

Materials and methods

We report our results with non-instrumented correction in perspective of a review of literature, serving as an important historical control. Database review identified 18 AS patients with CTK correction. After application of a Halo-Thoracic-Cast (HTC) patients underwent posterior non-instrumented open-wedge osteotomy at C7/T1 and osteotomy closure by threaded HTC-rod adjustments. Postoperative gradual HTC correction was continued for 2–4 weeks. Patients were invited for follow-up and medical charts were reviewed for demographics, surgical details, complications and outcomes. The patients’ preoperative, postoperative, before HTC removal and follow-up photographs were analyzed for the Chin-Brow-Vertical-Angle (CBVA), radiographs for the CTK angle.

Results

Patients’ age was 50 ± 11 years, follow-up was 37 ± 47 months and CBVA correction was 25° ± 9° (p < 0.000001). The final radiographic correction at follow-up was 20° ± 11° (p = 0.00002). At the latest follow-up, three patients judged their outcome as excellent, nine good, three moderate and one poor. Upon invitation, seven patients appeared with follow-up averaging 87 months. Neck-pain disability index was 8 ± 14 %. Two patients died, three were lost, one had revision elsewhere and five just had a routine follow-up. Six patients sustained a minor and ten a major complication. Revisions were indicated in five patients including infection, C8-radiculopathy and neurologic events by translation at the osteotomy. A total of 44 % of patients showed translation at the osteotomy indicating acute surgery with instrumentation twice after osteotomy closure, three patients had a revision posterior decompression and instrumented fusion for sequels related to translation.

Conclusion

With the non-instrumented HTC-based technique, average CBVA correction of 25° was achieved and all patients were ambulatory at follow-up. However, regarding translation at the osteotomy, loss of correction, morbidity of the HTC and lack of control at the osteotomy instrumentation-based correction and instrumented fusion seem to be preferable.     

Role of thoracoscopy for the sagittal correction of hypokyphotic adolescent idiopathic scoliosis patients

Purpose

Thoracic adolescent idiopathic scoliosis (AIS) curves (Lenke 1–4) are often characterized by hypokyphosis. Sagittal alignment remains challenging to correct, even with recent posterior segmental instrumentation. Some authors recommend anterior endoscopic release (AER) to reduce anterior column height, and facilitate thoracic kyphosis correction. The aim of this study was to assess the contribution of AER to sagittal correction in hypokyphotic AIS.

Methods

Fifty-six hypokyphotic (T4T12<20°) AIS patients were included. In group 1 (28 patients), patients first underwent AER, followed by posterior instrumentation and correction 5–7 days later. In group 2 (28 patients), patients underwent the same posterior procedure without AER. Posterior correction was performed in all cases using posteromedial translation and hybrid constructs consisting of lumbar pedicle screws and thoracic sublaminar bands. From radiological measurements performed using low-dose EOS radiographs, the correction of thoracic kyphosis was compared between the two groups.

Results

Groups 1 and 2 were comparable regarding demographic data and preoperative thoracic kyphosis (group 1: 11.7° ± 6.9° vs group 2: 12.1° ± 6.3°, p = 0.89). Postoperative thoracic kyphosis increase averaged 18.3° ± 13.6° in group 1 and 15.2° ± 9.0° in group 2. The benefit of anterior release was not statistically significant (p = 0.35).

Conclusion

Although previous studies have suggested that thoracoscopic release improved correction compared to posterior surgery alone, the current study did not confirm this finding. Moreover, results of the current series showed that no significant benefit can be expected from AER in terms of sagittal plane improvement when the posteromedial translation technique is used, even in challenging hypokyphotic patients.     

Skip pedicle screw fixation combined with Ponte osteotomy for adolescent idiopathic scoliosis

Purpose

This study aimed to determine whether Ponte osteotomy combined with skip pedicle screw fixation (SPSF) can improve the correction rate and restore thoracic kyphosis for patients with adolescent idiopathic scoliosis.

Methods

Surgical time, blood loss, preoperative Cobb angle of the main thoracic curve, flexibility, Cobb angle at 1 year after surgery, thoracic curve correction rate, and Cincinnati correction index (CCI) were determined for both the Ponte (n = 17) and non-Ponte (control; n = 21) groups. Furthermore, kyphotic angles at T5–T12 before and 1 year after the surgery were measured.

Results

The following measurements were obtained for the Ponte and control groups, respectively: surgical time, 236 ± 13 and 187 ± 9 min; blood loss, 1,141 ± 150 and 745 ± 120 g; preoperative Cobb angle of the main thoracic curve, 52.5° ± 10.4° and 51.5° ± 9.2°; flexibility, 31.7 ± 13.2 and 45.1 ± 12.3 % (p = 0.003); thoracic curve correction rate, 62.0 ± 2.5 and 63.6 ± 2.5 %; CCI, 2.2 ± 0.2 and 1.5 ± 0.1 (p = 0.003); preoperative kyphotic angle at T5–T12, 11.3° ± 11.2° and 13.0° ± 9.0°; and kyphotic angle at T5–T12 at 1 year after the surgery, 21.8° ± 1.7° and 24.2° ± 1.9°.

Conclusion

Ponte osteotomy was combined with SPSF in case of rigid curve. CCI was significantly greater in the Ponte group. Postoperative thoracic kyphotic angles were identical in both groups.     

Can acetabular orientation be restored by lumbar pedicle subtraction osteotomy in ankylosing spondylitis patients with thoracolumbar kyphosis?

Purpose

To evaluate whether acetabular orientation (abduction and anteversion) can be restored by lumbar pedicle subtraction osteotomy (PSO) in ankylosing spondylitis (AS) patients with thoracolumbar kyphosis.

Materials and methods

A total of 33 consecutive AS patients with thoracolumbar kyphosis undergoing one-level lumbar PSO were retrospectively reviewed. Radiographical measurements included sagittal vertical axis, global kyphosis, thoracic kyphosis, local kyphosis, lumbar lordosis, pelvic incidence, sacral slope, and pelvic tilt. Acetabular abduction and anteversion were measured on CT scans of the pelvis before and after lumbar PSO. The preoperative and postoperative parameters were compared by the paired samples t test. Pearson’s correlation analysis was conducted to determine the correlations between the changes in acetabular abduction and anteversion and the changes in sagittal spinopelvic parameters.

Results

After lumbar PSO, sagittal vertical axis, global kyphosis, and pelvic tilt were corrected from 15.7 ± 6.7 cm, 66.8° ± 17.5°, and 38.6° ± 9.0° to 2.9 ± 4.9 cm, 21.3° ± 8.2°, and 23.2° ± 8.2°, respectively (p < 0.001). Of note, acetabular abduction and anteversion decreased from 59.6° ± 4.6° to 31.4° ± 6.5° before surgery to 51.4° ± 6.5° and 20.2° ± 4.4° after surgery, respectively (p < 0.001). Moreover, the changes in acetabular abduction and anteversion were observed significantly correlated with the change in pelvic tilt (r = 0.527, p = 0.002; r = 0.586, p < 0.001).

Conclusion

Abnormal acetabular abduction and anteversion could be corrected by lumbar PSO in AS patients with thoracolumbar kyphosis. Consequently, a relatively normal acetabular orientation could be achieved after lumbar PSO, which might decrease the potential risk of dislocation in AS patients with spine and hip deformities requiring subsequent THR surgery.

     

The posterior surgical correction of congenital kyphosis and kyphoscoliosis: 23 cases with minimum 2 years follow-up

Purpose

The purpose of this study is to review our operative experience of congenital kyphosis or kyphoscoliosis undergoing either pedicle subtraction osteotomy (PSO) or posterior vertebral column resection (pVCR) according to certain criteria we have established.

Methods

From December 2003 to 2009, 23 consecutive patients of congenital kyphosis or kyphoscoliosis were treated by means of PSO or pVCR procedure in a single institution. The average preoperative kyphosis angle was 74.3º. The C7 plumb line was 12.6 mm posterior to the posterior–superior corner of S1 on average, showing negative imbalance. In the 11 cases who had accompanied scoliosis, the average preoperative scoliosis angle was 42.6º. The average Oswestry Deficiency Index (ODI) for back pain was 14.6 before surgery. Eleven patients had compromise of neurological functions.

Results

After PSO or pVCR procedure, the average kyphosis angle decreased to 20.0º, and the accompanied scoliosis also decreased to 15.8º. The average follow-up time after surgery was 34.3 months. At the last follow-up, the average kyphosis corrective rate was 73.7 %, and the average scoliosis corrective rate was 61.7 %. The negative imbalance improved, with the C7 plumb line being 1.5 mm posterior to the posterior–superior corner of S1 on average. After surgery, the average ODI for back pain had 40.6 % improvement, and most patients who had neurological symptoms before surgery had varying degrees of relief. The total satisfactory rate to corrective surgery was 91.3 %. No permanent neurological damage was observed.

Conclusions

If selected appropriately, both PSO and pVCR procedures can achieve compatible and satisfactory correction results in the surgical treatment of congenital kyphosis or kyphoscoliosis.     

Adolescent idiopathic scoliosis treated with posteromedial translation: radiologic evaluation with a 3D low-dose system

Purpose

Computed tomography can be used for three-dimensional (3D) evaluation of adolescent idiopathic scoliosis (AIS) patients, but at the expense of high radiation exposure, and with the limitation of being performed in the supine position. These drawbacks can now be avoided with low-dose stereoradiography, even in routine clinical use. The purpose of this study was to determine the 3D postoperative correction of AIS patients treated by posteromedial translation.

Methods

Forty-nine consecutive patients operated for AIS (Lenke 1–4) using posteromedial translation were included. Corrections were evaluated preoperatively, postoperatively and after at least 2 years using the EOS imaging system. 3D angles were measured in the plane of maximum deformity.

Results

Mean number of levels fused and operative time were 13.5 ± 1 and 215 ± 25 min, respectively. Main thoracic, proximal thoracic, and lumbar curves corrections averaged 64.4 ± 18, 31 ± 10 and 69 ± 20 %, respectively. Mean T4–T12 kyphosis increased 18.8° ± 9° in the subgroup of hypokyphotic patients. Mean apical vertebral rotation reduction was 48.3 ± 20 %. Trunk height gain averaged 27.8 ± 14 mm. There was no pseudarthrosis or significant loss of correction in any plane during follow-up. Two patients (4 %) developed asymptomatic proximal junctional kyphosis, despite having normal thoracic kyphosis. Their sagittal balance was shifted posteriorly by 36 and 47 mm, respectively, by the operation, but revision surgery was not performed.

Conclusions

Low-dose stereoradiography provided 3D reconstructions of the fused and unfused spine in routine clinical use. Postoperative 3D analysis showed that posteromedial translation enhanced sagittal balance correction, without sacrificing frontal or axial correction of the deformity.     

The aim of this retrospective study is to evaluate the efficacy and safety of posterior-only vertebral column resection (PVCR) for the treatment of angular and isolated congenital kyphosis

Purpose

The aim of this retrospective study is to evaluate the efficacy and safety of posterior-only vertebral column resection (PVCR) for the treatment of angular and isolated congenital kyphosis.

Methods

24 patients with isolated angular congenital kyphosis treated by PVCR in our hospital were retrospectively studied. The patients’ radiographs and hospital records were reviewed. Deformity in sagittal planes and global sagittal alignment were analyzed for correction and maintenance of the correction in preoperative, postoperative, and follow-up radiographs. The complications and related risk factors were analyzed.

Results

The average age was 13.9 (4–40) years. Three of them were revision surgeries. Two patients have intraspinal anomalies. The mean follow-up is 56.9 (26–129) months. The mean operation time was 293.1 (170–480) min. The averaged blood loss was 993.8 (250–3000) ml. The segmental kyphosis was 87.3° before surgery, 17.6° post surgery and 20.4° at the latest the follow-up. And the sagittal vertical axis was improved from 43.1 mm to 9.2 mm. Mean total score of SRS-22 was 89.3. Complications occurred in 4 patients, including 1 screw pullout due to pseudarthrosis, 1 proximal junctional kyphosis, 1 incomplete spinal cord injury and 1 root injuries.

Conclusion

Posterior-only vertebral column resection is an ideal procedure for severe rigid congenital kyphosis. However, it is still a highly technical demanding procedure. Neurological compromises still remain the biggest challenges. Sufficient height of anterior reconstruction, avoidance sacrifice of bilateral roots in the same level in the thoracic spine, avoidance of the sagittal translation of the upper and lower vertebras, intra-operative neuromonitoring, and preoperative surgical release of diastematomyelia and tethered cord may help to improve the safety.

     

A comparative analysis of sagittal spinopelvic alignment between young and old men without localized disc degeneration

Introduction

The purpose of this study was to compare the sagittal spinopelvic parameters between young normal asymptomatic adults and older normal asymptomatic adults without localized segmental disc degeneration.

Materials and methods

Standing sagittal radiographs of the whole spine including the pelvis in 342 adult male volunteers (Group 1: n = 184, average age 21.2 years, range 19–28 vs. Group 2: n = 158, average age 63.8 years, range 53–79) were analyzed prospectively. Volunteers with history of spine operation, spinal disease, chronic pain in their back or legs, scoliosis, spondylolisthesis, 1–3 segmental disc space narrowing, and/or compression fractures in radiographs were excluded. The following parameters were included: thoracic kyphosis between T5 upper endplate (UEP) and T12 lower endplate (LEP), thoracolumbar kyphosis (T10 UEP ? L2 LEP), T12 LEP-horizontal (H) angle (minus denotes EP above the H line), lumbar lordosis (T12 LEP ? S1 UEP), lower lumbar lordosis (L4 UEP ? S1 UEP), sacral slope, pelvic incidence and distances from C7 plumb/T12 plumb to the postero-superior endplate of S1. Group 2 (old men group) demonstrated larger thoracic kyphosis (30.1° ± 8.6° vs. 21.1° ± 7.8° in Group 1, P < 0.001), thoracolumbar kyphosis (10.0° ± 7.5° vs. 2.8° ± 7.1° in Group 1, P < 0.001), total lumbar lordosis at T12–S1 (57.3° ± 8.8° vs. 52.2° ± 9.2° in Group 1, P < 0.001), lower lumbar lordosis at L4–S1 (39.4° ± 6.7° vs. 32.4° ± 6.4° in Group 1, P < 0.001), a higher ratio of lower to total lumbar lordosis (69.5 ± 11.6 vs. 62.7 ± 10.6 % in Group 1, P < 0.001) and T12 LEP-H angle (?20.4° ± 5.7° vs. ?15.7° ± 5.1° in Group 1, P < 0.001). There were no significant differences in sacral slope (36.5° ± 7.3° in Group 1 vs. 36.8° ± 6.7° in Group 2, P = 0.67) and pelvic incidence (46.5° ± 7.7° in Group 1 vs. 48.2° ± 8.5° in Group 2, P = 0.06). There was no significant difference in the measurement of distance from C7 plumb to the postero-superior endplate of S1 (?0.7 ± 2.4 cm in Group 1 vs. ?0.3 ± 2.7 cm in Group 2, P = 0.197). However, the distance from T12 plumb to the postero-superior endplate of S1 (?0.7 ± 1.7 cm in Group 1 vs. ?2.2 ± 1.7 cm in Group 2, P < 0.001) demonstrated a significant difference.

Conclusion

The old men group demonstrated a significant increase in thoracic kyphosis, thoracolumbar kyphosis, total and lower lumbar lordosis, a higher ratio of lower to total lumbar lordosis, and a longer distance from T12 plumb to the postero-superior endplate of S1 without changes in sacral slope and global sagittal balance.     

Hemivertebrae resection for unbalanced multiple hemivertebrae: is it worth it?

Purpose

To assess the correction effect of hemivertebra resection for unbalanced multiple hemivertebrae by measuring corresponding parameters in both coronal and sagittal planes on series posteroanterior and lateral radiographs and report the related complications.

Methods

Twelve children with unbalanced multiple hemivertebrae were operated on by hemivertebra resection through a combined anterior and posterior approach or a posterior-only procedure. Mean age at time of surgery was 9.8 years (range 2–14 years). They were retrospectively studied with a mean follow-up of 48.7 months (range 30–60 months).

Results

The mean Cobb angle of the main curve was 65.3° (range 45°–92°) before surgery and 13.8° (range 4°–30°) at the last follow-up. The correction rate was 80.0 % (range 65.5–92.4 %). The compensatory cranial curve was corrected from 25.8° (range 5°–53°) to 11.7° (range 0°–34°) with a correction rate of 65.9 % (range 33.3–100 %), and the compensatory caudal curve was corrected from 32.4° (range 17°–57°) to 7.1° (range 0°–20°) with a correction rate of 81.4 % (range 53.1–100 %). The angle of segmental kyphosis was 41.3° (range 12°–76°) before surgery and 17.0° (range ?12° to 45°) at the final follow-up. The coronal imbalance was ?1.0 cm (range ?3.5 to 3 cm) before surgery and 0.0 cm (range ?1.0 to 1.5 cm) at the most recent follow-up. The sagittal imbalance was 0.9 cm (range ?3.2 to 3 cm) before surgery and 0.6 cm (range ?3.0 to 3.5 cm) at the most recent follow-up. Complications including pedicle fractures, and pseudarthrosis were found in two patients (20 %).

Conclusions

In the patients with unbalanced multiple hemivertebrae, hemivertebra resection allows for excellent correction in both the coronal and sagittal planes, and great care should be taken to reduce the rate of complications.     

Sagittal balance correction of idiopathic scoliosis using the in situ contouring technique

Purpose

Idiopathic scoliosis can lead to sagittal imbalance. The relationship between thoracic hyper- and hypo-kyphotic segments, vertebral rotation and coronal curve was determined. The effect of segmental sagittal correction by in situ contouring was analyzed.

Methods

Pre- and post-operative radiographs of 54 scoliosis patients (Lenke 1 and 3) were analyzed at 8 years follow-up. Cobb angles and vertebral rotation were determined. Sagittal measurements were: kyphosis T4–T12, T4–T8 and T9–T12, lordosis L1–S1, T12–L2 and L3–S1, pelvic incidence, pelvic tilt, sacral slope, T1 and T9 tilt.

Results

Thoracic and lumbar curves were significantly reduced (p = 0.0001). Spino-pelvic parameters, T1 and T9 tilt were not modified. The global T4–T12 kyphosis decreased by 2.1° on average (p = 0.066). Segmental analysis evidenced a significant decrease of T4–T8 hyperkyphosis by 6.6° (p = 0.0001) and an increase of segmental hypokyphosis T9–T12 by 5.0° (p = 0.0001). Maximal vertebral rotation was located at T7, T8 or T9 and correlated (r = 0.422) with the cranial level of the hypokyphotic zone (p = 0.003). This vertebra or its adjacent levels corresponded to the coronal apex in 79.6 % of thoracic curves.

Conclusions

Lenke 1 and 3 curves can show normal global kyphosis, divided in cranial hyperkyphosis and caudal hypokyphosis. The cranial end of hypokyphosis corresponds to maximal rotation. These vertebrae have most migrated anteriorly and laterally. The sagittal apex between segmental hypo- and hyper-kyphosis corresponds to the coronal thoracic apex. A segmental sagittal imbalance correction is achieved by in situ contouring. The concept of segmental imbalance is useful when determining the levels on which surgical detorsion may be focused.     

Sagittal alignment of the cervical spine in adolescent idiopathic scoliosis treated by posteromedial translation

Purpose

To analyze postoperative changes in the cervical sagittal alignment (CSA) of patients with AIS treated by posteromedial translation.

Methods

49 patients with thoracic AIS underwent posterior arthrodesis with hybrid constructs, combining lumbar pedicle screws and thoracic universal clamps. Posteromedial translation was the main correction technique used. 3D radiological parameters were measured from low-dose biplanar radiographs. CSA was assessed using the C2C6 angle, and the central hip vertical axis (CHVA) was used as a reference axis to evaluate patients’ balance.

Results

Preoperatively, 58 % of patients had thoracic hypokyphosis, and 79 % had a kyphotic CSA. Significant correlation was found (r = 0.45, P = 0.01) between thoracic hypokyphosis and cervical kyphosis. Increase in T4–T12 thoracic kyphosis (average 14.5° ± 10°) was associated with significant decrease in cervical kyphosis in the early postoperative period. The CSA further improved spontaneously during follow-up by 7.6° (P < 0.0001). Significant positive correlation (r = 0.32, P = 0.03) was found between thoracic and cervical improvements. At latest follow-up, 94 % of the patients were normokyphotic and 67 % had a CSA in the physiological range. Sagittal balance of the thoracolumbar spine was not significantly modified postoperatively. However, the procedure significantly changed the position of C2 in regard to the CHVA (C2–CHVA), which reflects headposition (P = 0.012). At last follow-up, the patients sagittal imbalance was not significantly different from the preoperative imbalance (P = 0.34).

Conclusions

Thoracic hypokyphosis and cervical hypolordosis, observed in AIS, can be improved postoperatively, when the posteromedial translation technique is used for correction. The cervical spine remains adaptable in most patients, but the proportion of patients with physiological cervical lordosis at final follow-up remained low (24.5 %).     

Posterior-only correction of Scheuermann kyphosis using pedicle screws: economical optimization through screw density reduction

Introduction

Posterior-only approach using pedicle screws’ fixation has emerged as the preferred surgical technique for Scheuermann kyphosis (SK) correction. Insertion of multiple pedicle screws while increasing stability increases also the risk of complications related to screw malpositioning and surgical cost. The optimal screw density required in surgical correction of SK remains unclear. This study compares the safety and efficacy of low screw density (LSD) versus high screw density (HSD) technique used in posterior-only correction of SK.

Methods

Twenty-one patients underwent surgical correction of SK between 2007 and 2011 and were reviewed after a mean of 29 months. HSD technique (i.e., 100 % of available pedicles, averaged 25.2 ± 4 screws) was used in 10 cases and LSD technique (i.e., 54–69 % of available pedicles in a pre-determined pattern, averaged 16.8 ± 1.3 screws; p < 0.001) was used in 11 cases. Kyphosis correction was assessed by comparing thoracic kyphosis, lumbar lordosis and sagittal balance on preoperative and postoperative radiographs. Cost saving analysis was performed for each group.

Results

Preoperative thoracic kyphosis, lumbar lordosis and sagittal balance were similar for both groups. The average postoperative kyphosis correction was similar in both HSD and LSD groups (29° ± 9° vs. 34° ± 6°, respectively; p = 0.14). Complication occurred in four patients (19 %) in the HSD group and in two patients (9 %) in the LSD group (p = 0.56). Three patients required re-operation. Compared to HSD using LSD saves 4,200£ per patient in hardware and 88,200£ for the entire cohort.

Conclusion

LSD technique is as safe and effective as HSD technique in posterior-only correction of SK. Implant-related cost could be reduced by 32 %.     

Rotational osteotomy with submuscular plating in skeletally immature patients with cerebral palsy

Background

In cerebral palsy, intoeing gait with increased femoral anteversion is not uncommon and often requires surgical intervention. Although several conventional methods have been used, complications are common. We applied a new technique of rotational osteotomy with submuscular plating in skeletally immature patients with cerebral palsy.

Methods

Eighteen patients (26 femora, 8 bilateral) with a mean age of 8.7 years (range, 6–16) were prospectively treated with this technique. The anatomic distribution of patients was hemiplegia (n = 7), diplegia (n = 8), and asymmetric diplegia (n = 3). Percutaneous osteotomy was performed at the middle of the femoral shaft. After rotational correction, submuscular plating was done using a locking compression plate. Femoral anteversion was evaluated by a trochanteric prominence angle test (TPAT) and computed tomography.

Results

In all cases, each osteotomy healed in an average of 12 weeks (range, 10–14). The mean femoral anteversion by TPAT improved to 12° (range, 5°–30°) after surgery from 44° (range, 30°–65°) (p < 0.001). There were no complications of deep infection, implant failure, or limb length discrepancy over 1 cm.

Conclusions

In skeletally immature patients with cerebral palsy, femoral anteversion can be safely corrected using submuscular plating with a locking compression plate.     

Multiple concave rib head resection improved correction rate of posterior spine fusion in treatment of adolescent idiopathic scoliosis

Background

Hybrid constructs have been widely used to surgically correct thoracic adolescent idiopathic scoliosis (AIS). To enhance the correction obtained with hybrid constructs, we perform concave rib head resection and convex costovertebral release as posterior release procedures. The objective of the study was to evaluate coronal and sagittal curve correction in patients with adolescent idiopathic scoliosis (AIS) treated with hybrid constructs combined with concave rib head resection and convex transverse process resection as posterior release procedures.

Preventive effects of conservative treatment with short-term teriparatide on the progression of vertebral body collapse after osteoporotic vertebral compression fracture

Summary

The progression of fractured vertebral collapse is not rare after a conservative treatment of vertebral compression fracture (VCF). Teriparatide has been shown to directly stimulate bone formation and improve bone density, but there is a lack of evidence regarding its use in fracture management. Conservative treatment with short-term teriparatide is effective for decreasing the progression of fractured vertebral body collapse.

Introduction

Few studies have reported on the prevention of collapsed vertebral body progression after osteoporotic VCF. Teriparatide rapidly enhances bone formation and increases bone strength. This study evaluated preventive effects of short-term teriparatide on the progression of vertebral body collapse after osteoporotic VCF.

Methods

Radiographs of 68 women with single-level osteoporotic VCF at thoracolumbar junction (T11–L2) were reviewed. Among them, 32 patients were treated conservatively with teriparatide (minimum 3 months) (group I), and 36 were treated with antiresorptive (group II). We measured kyphosis and wedge angle of the fractured vertebral body, and ratios of anterior, middle, and posterior heights of the collapsed body to posterior height of a normal upper vertebra were determined. The degree of collapse progression was compared between two groups.

Results

The progression of fractured vertebral body collapse was shown in both groups, but the degree of progression was significantly lower in group I than in group II. At the last follow-up, mean increments of kyphosis and wedge angle were significantly lower in group I (4.0°?±?4.2° and 3.6°?±?3.6°) than in group II (6.8°?±?4.1° and 5.8°?±?3.5°) (p?=?0.032 and p?=?0.037). Decrement percentages of anterior and middle border height were significantly lower in group I (9.6?±?10.3 and 7.4?±?7.5 %) than in group II (18.1?±?9.7 and 13.8?±?12.2 %) (p?=?0.001 and p?=?0.025), but not in posterior height (p?=?0.086).

Conclusions

In female patients with single-level osteoporotic VCF at the thoracolumbar junction, short-term teriparatide treatment did not prevent but did decrease the progression of fractured vertebral body collapse.     

Reciprocal sagittal alignment changes after posterior fusion in the setting of adolescent idiopathic scoliosis

Purpose

Surgical adolescent idiopathic scoliosis (AIS) management can be associated with loss of thoracic kyphosis and a secondary loss of lumbar lordosis leading to iatrogenic flatback. Such conditions are associated with poorer clinical outcomes during adulthood. The aim of this study was to evaluate sagittal plane reciprocal changes after posterior spinal fusion in the setting of AIS.

Methods

Thirty consecutive adolescents (mean age 14.6 years) with AIS Lenke 1, 2 or 3 were included in this retrospective study with 2 year follow-up. Full-spine standing coronal and lateral radiographs were obtained preoperatively, at 3 and 24 months postoperatively. Coronal Cobb angle, thoracic kyphosis (TK) and lumbar lordosis (LL) were measured. Surgical procedure was similar in all the cases, with use of pedicular screws between T11 and the lowest instrumented vertebra (≥L2), sublaminar hooks applied in compression at the upper thoracic level and sub-laminar bands and clamps in the concavity of the deformity. Statistical analysis was done using t test and Pearson correlation coefficient.

Results

Between preoperative and last follow-up evaluations a significant reduction of Cobb angle was observed (53.6° vs. 17.2°, p < 0.001). A significant improvement of the instrumented thoracic kyphosis, TK (19.7° vs. 26.2°, p < 0.005) was noted, without difference between 3 and 24 months postoperatively. An improvement in lumbar lordosis, LL (43.9° vs. 47.3°, p = 0.009) was also noted but occurred after the third postoperative month. A significant correlation was found between TK correction and improvement of LL (R = 0.382, p = 0.037), without correlation between these reciprocal changes and the amount of coronal correction.

Conclusion

Results from this study reveal that sagittal reciprocal changes occur after posterior fusion when TK is restored. These changes are visible after 3 months postoperatively, corresponding to a progressive adaptation of patient posture to the surgically induced alignment. These changes are not correlated with coronal plane correction of the deformity. In the setting of AIS, TK restoration is a critical goal and permits favorable postural adaptation. Further studies will include pelvic parameters and clinical scores in order to evaluate the impact of the noted reciprocal changes.     

Effectiveness of pedicle screw-based ligamentotaxis in reducing preoperative kyphosis in thoracolumbar spinal fractures: a retrospective analytical study based on injury surgery interval

Objectives

Although there is an agreement of using long-level construct than short-level construct to correct the kyphosis, no literature mentioned the success of this treatment based on timing of surgery after the injury. Objective of this paper was to study the effect of ligamentotaxis on preventing the development of postoperative kyphosis in unstable thoracolumbar burst fractures based on injury surgery interval (ISI).

Study design

This is a retrospective analysis in 67 patients with unstable thoracolumbar burst fractures operated with posterior-only pedicle screw fixation.

Methods

A retrospective analytical study was conducted in 67 patients who had unstable thoracolumbar fracture and operated with posterior-only pedicle screw construct two levels above and one level below the fractured vertebra. Results were analyzed based on ISI: group 1 (34 patients) was operated within 7 days; group 2 (19 patients) operated between 7 and 14 days; and group 3(14 patients) operated after 14 days of injury. Immediate postoperative and final follow-up kyphotic angles were analyzed among all three groups using Kruskal–Wallis test. Complications regarding implant failure were also noted at final follow-up.

Results

Average follow-up was 37 ± 8.1 months. Average preoperative kyphosis at thoracolumbar junction was 26.3° ± 3.9°, 26.3° ± 2.9° and 26.3° ± 2.8° in groups 1, 2 and 3, respectively, which did not show any difference (P = 0.98). Immediate postoperatively kyphotic angle was improved to 4.3° ± 1.9°, 5.4° ± 1.7° and 10.1° ± 3.0° in groups 1, 2 and 3, respectively, which exhibited statistically significant difference (P < 0.001); and at final follow-up kyphotic angles were 5.4° ± 1.9°, 7.2° ± 1.7° and 15.0° ± 1.6° in groups 1, 2 and 3, respectively showing 1.1°, 1.7° and 4.9° loss in correction at final follow-up. Comparison of kyphotic angles and loss of kyphotic angles amongst the three groups showed statistically significant difference (P < 0.001). Two patients from group 3 had implant failure that required implant extraction.

Conclusion

Posterior-only pedicle screw fixation in unstable thoracolumbar fractures would correct and maintain the postoperative correction in kyphosis, at least at 3-year follow-up, without increasing implant failure if ISI is less than 2 weeks. While patients operated after 2 weeks of injury would require additional anterior procedure.     

SRS-Schwab Grade 4 osteotomy for congenital thoracolumbar kyphosis: a minimum of 2 years follow-up study

Background Context

Several osteotomy techniques including pedicle subtraction osteotomy and vertebral column resection have been employed in the correction of congenital kyphosis (CK) and satisfying outcomes have been demonstrated. However, the Scoliosis Research Society (SRS)-Schwab Grade 4 osteotomy, defined as resection of posterior elements, partial vertebral body, and superior adjacent disc, is rarely reported in the treatment of CK.