Aims

Magnetically controlled growing rods (MCGR) have been gaining popularity in the management of early-onset scoliosis (EOS) over the past decade. We present our experience with the first 44 MCGR consecutive cases treated at our institution.

A retrospective review of patients with spinal growing rods in a single institution. Demographic data including age at first surgery, diagnosis, pre- and post-operative cobb angles from erect standardised radiographs were collected. The type of construct used i.e. spine to rib or spine to spine was noted along with the type of growing mechanism used (magnetic or cassette). Any complications were collated for each technique.

Our results include 26 patients who had growing rod insertion, 12 in the spine - spine group and 14 in rib - spine group. Pre-operative cobb angles of 71 and 78 degrees respectively with a correction to 36 and 35 degrees. Mean age at surgery was 63 months in spine to spine group and 67 months in rib to spine group. Spine to spine group had 2 proximal pull out of hooks and the rib spine group had one pull out of hook.

The correction achieved by the new technique is comparable to the spine – spine constructs. Complications are seen in both groups. The perceived benefit of the new technique is the proximal spine is not violated so there is a reduced risk of mass fusion. The canal and pedicles are not included proximally, so there will be no effect on the growing diameter of the canal. Biomechanically the construct is more robust and should allow greater control of the curve. Further follow up and analysis of this new technique is warranted.

The use of serial casting in the management of early onset scoliosis (EOS) has been well described. Our aim was to evaluate outcomes of plaster jacket therapy in patients with EOS from a tertiary referral centre.

A retrospective review of hospital records and PACS images of 27 patients to identify patients treated with serial casting over a five year period. The primary outcome measure was the need for surgical intervention, with change in Cobb angle used as a secondary outcome measure

Mean age at presentation was 14 months (range 10 – 42), including 14 male and 13 female patients, with an average follow-up of 34 months. Curves were categorised according to aetiology: 16 idiopathic, 6 syndromic, 3 congenital and 2 neuromuscular curves. The mean Cobb angle at diagnosis was 43.7° (range 22 – 115) and mean rib vertebral angle difference (RVAD) was 22.2° (8 – 70). Duration of treatment was 9.9 months (range 3 – 27), with an average of two plaster jacket changes per child. At the time of review, patients fell into one of three groups. Group one (10 patients) failed conservative treatment due no improvement in Cobb angle (mean 48.4° compared with pre-op 53.9°, p value 0.55) and either had insertion of growing rods or had been listed for this procedure, at a mean age of 51.8 months. Group two (12 patients) had a mean Cobb angle of 38.9° pre-treatment which improved to 23.5° (p value <0.05) and were either treated in a brace or had discontinued treatment. The mean RVAD at initial diagnosis was 36.6° in group 1 compared with 13.8° in group 2 (p<0.05). All patients in group one requiring surgical treatment had an RVAD of greater than 20°. Serial casting is on-going for five patients (group three). Complications occurred in 30% of patients including pressure sores, chest infection and respiratory compromise requiring intubation.

Current NICE guidance recognises that serial casting ‘rarely corrects scoliosis’ but recommends it may be used ‘to allow growth before a more permanent treatment is offered’. In our experience, serial casting did not allow any patients with a progressive scoliosis (determined by an RVAD of greater than 20°), to reach a single definitive fusion. However serial casting appeared to halt to curve progression until the child was suitable for the insertion of a growing rod system.

Introduction:

Scheuermann's kyphosis is a fixed round back deformity characterised by wedged vertebrae seen on radiograph. It is known patients presented with a negative sagittal balance before operation. Few studies investigated the outcome after operation, especially the change in the lumbar hyperlordosis.

Pedicle screw constructs (PSC) in scoliosis are a recently established and widely accepted method of managing scoliotic curves posteriorly. There is a perceived improved coronal and rotational correction when compared to other posterior only constructs. With continued use of this method, the authors and deformity surgeons in general have become aware of persistent thoracic hypokyphosis.

This review of 3 years of scoliosis cases using PSC looks at four different implant strategies utilised to manage this problem and our current practice. These strategies were:

All titanium 5.5 mm rod diameter (Expedium, Depuy spine)

All titanium 5.5 mm rod diameter with periapical washers (Expedium, Depuy spine)

All titanium 6.0 mm rod diameter (Pangea, Synthes)

Titanium pedicle screws with 5.5 mm diameter cobalt chrome rods (Expedium Depuy spine)

We have reviewed our outcomes with these strategies with respect to thoracic hypokyphosis. Strategy 1 had the highest rate of hypokyphosis on postoperative radiographs. Strategy 4 seems to have the best correction of coronal and sagittal plane abnormality post operatively. As a consequence, our current practice is the use of titanium pedicle screws and 5.5 mm diameter cobalt chrome rods when managing scoliosis with a pedicle screw construct.

Background: The cells of the intervertebral disc must synthesise and maintain their surrounding matrix for it to function normally, providing all its physiological and mechanical properties. However, disc cells survive in an environment that most cells would not tolerate, ie with a low pH and relatively little oxygen. Cells which experience such potentially damaging conditions, including excessive heat, elicit a stress response and synthesise a range of proteins, called heat shock proteins (Hsps); these facilitate repair and survival or removal of damaged cells.

Methods and Results: We have studied Hsp production by disc cells, both in vitro and in vivo. We measured Hsps produced by bovine skin and disc cells grown in monolayer and heated up to 45°C and also immunostained human surgical discs for stress proteins, Hsp27 and Hsp72.

Disc cells responded differently to dermal fibroblasts; when freshly isolated they had a reduced or attenuated stress response and produced much less Hsp 70 than freshly isolated skin cells. After culturing in monolayer (by passage 2) all cells produced more Hsps. Human surgical discs produced varying amounts of Hsp, with most being produced by cells in herniated discs, particularly those within clusters of cells.

Conclusion: Our results suggest that intervertebral disc cells in vivo normally have a reduced stress response. Hsp production is considered to protect against damage, suggesting that the reduced response may contribute to disc degeneration and back pain. The prosurvival stress response of disc cells could provide a novel therapeutic target in patients with degenerative disc disease.

Conflict of Interest: None

Source of Funding: Wolfson Charitable Trust

Introduction: Spinous process osteotomy (SPO) and multiple laminotomy can be used for multi-level lumbar decompression. We conducted an experimental study to compare the effects of these two methods on spinal kinetics.

Method: Ten fresh calf spines (L2- sacrum) were mounted in dental stone and segmental motion of L3 relative to L5 was assessed using an electromagnetic 3-D motion detection system (FASTRAK, Polhemus, Colchester, VT, USA). Pure moments of 0, 2.5, 5, 7, and 10 Nm were used in flexion/extension, right/left lateral bending, and right/left axial rotation. The moments were generated by applying two equal and opposite forces (weights) to the perimeter of a plastic circular disc, which was fixed to the superior end plate of L3 by three screws. In five spines decompression was performed at L3/4 and 4/5 using standard laminotomy technique. Decompression using SPO was done at L3–5 through a unilateral approach in the rest. Segmental mobility between the two methods was compared using the Mann-Whitney test.

Results: Mean range of motion in the specimens before intervention was-lateral bending (32.70 ± 7.6 SD), rotation (13.10 ± 4.8 SD), flexion/extension (19.30 ± 7.1 SD). There was statistically significant difference between mean increase in lateral bending after SPO to that following laminotomy (4.00 ± 1.5 SD vs 0.60 ± 1.6 SD; p=0.008). Mean increase in flexion- extension after SPO was not significantly different from that after laminotomy (4.50 ± 1.1 SD vs 3.90 ± 3.8 SD; p= 0.75). There was no difference in the mean increase in axial rotation after SPO compared to that following laminotomy (7.90 ± 3.6 SD vs 6.80 ± 5.0 SD; p= 0.75).

Conclusions: Both laminotomy and SPO produced increased range of motion in a calf spine model. SPO produced significant increase in lateral bending although its clinical significance is unknown.

Ethics approval: none

Interest Statement: Local grant (Research Fund, Centre for Spinal Studies, Robert Jones and Agnes Hunt Hospital, UK

Objective The hypothesis of this study is that the flexibility of idiopathic scoliosis curves as measured by traction radiography performed under general anaesthetic (TUA) will be superior to supine bending radiography. Subsequently, this may aid in determining the surgical approach, sparing patients anterior release surgery, and show greater correlation with the postoperative result. This is a new technique, not previously reported in the literature.

Design A prospective comparison between TUA and supine bending radiography to determine curve flexibility, and examine their relationship with anterior release surgery and postoperative correction.

Subjects This study was based on 21 patients with a diagnosis of idiopathic scoliosis, admitted for corrective surgery at our unit.

Outcome measures The amount of correction achieved by each of the two methods on the preoperative curve was examined using a paired t-test. The influence of the TUA on the decision for anterior release surgery was noted, along with the correlation of each method with postoperative correction.

Results On statistical analysis with a paired t-test, TUA showed significantly greater curve flexibility than that shown by supine bending radiographs (p< 0.001) irrespective of curve classification or magnitude. Of the 11 patients planned for anterior release surgery with posterior fusion, the use of TUA obviated this in 9 (82%) by demonstrating greater preoperative curve flexibility. Excluding thoracolumbar curves, TUA showed significantly greater postoperative correlation than supine bending radiography (R=0.79, R=0.61 respectively).

Conclusion In our unit, traction radiography performed under general anaesthetic is superior to supine bending radiography in assessing curve mobility prior to surgery. Performing TUA has significant benefits to patients in avoiding unnecessary anterior release surgery, and has greater correlation with postoperative correction. In studying fulcrum bending radiographs, Cheung1 showed similar benefits in avoiding anterior release and we therefore recommend the use of these methods by other institutions.

Introduction: The incidence of scoliosis in patients with myelomeningocele has been reported to be as high as 80 to 90% in some studies. However these studies included patients with both congenital and developmental curves. The purpose of this study is to identify clinical and radiological factors, which may predict the development of scoliosis in patients with myelomeningocele.

Methods: A retrospective review of the charts and radiographs of all patients with myelomeningocele seen in our clinic between 1990 and 1995 was performed. Selection criteria for the study included: a diagnosis of myelo-meningocele or lipomeningocele, age greater than 10 years, serial documentation of motor power testing, and a radiographic documentation of spinal deformity primarily in the coronal plane.

Statistical analysis was performed to obtain predictive values, specificity and sensitivity for each of the following factors: clinical motor level, functional status, motor asymmetry and hip instability.

Radiographs were examined to obtain the last intact laminar arch in these patients. The relationship between the last intact laminar arch and scoliosis was evaluated.

Results: 141 patients satisfied the inclusion criteria. Seventy-four patients (53%) developed scoliosis. The mean follow-up was 9.4 years (range 3–30 years). The average age of the patient population was 19 (range 10–42 years). Forty-three patients developed scoliosis before nine years of age. New curves continued to develop until 15 years of age. Curves less than 20° often resolved. Clinical motor level, functional status, motor asymmetry and the last intact laminar arch were all found to be predictive for scoliosis in these patients. The presence of spasticity and hip instability had no definite influence on the development of scoliosis.

Conclusion: The term scoliosis should be reserved for curves greater than 20° in patients with myelomeningocele. New curves may continue to develop until 15 years of age. The last laminar arch is a useful early indicator of scoliosis in these patients.