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Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 443 - 443
1 Aug 2008
McMaster M Lee A Burwell R
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Objective: Infants introduced to indoor heated swimming pools in the first year of life show an association with progressive adolescent idiopathic scoliosis (AIS). Similarly control children exposed in this way show an association with vertical spinous process asymmetry. A new method of assessment was used on these controls who were standing in an upright position. Overall, our evidence suggests that indoor heated swimming pools contain a risk factor that predisposes some infants to develop spinal asymmetries years later – progressive AIS in a few and off-vertical spinous process asymmetry in the many. What the risk factor may be and its possible portal of entry into the infant’s body are unknown and possibilities are examined. A subsequent new group of control children confirms the association of indoor heated swimming pools and vertical spinal asymmetry.

Risk factors: An irritant gas trichloramine (nitrogen trichloride) has been found to contaminate the air of indoor-chlorinated pools which Bernard et al link to asthma and chronic airway inflammation. Besides the lungs the skin in infants may provide another portal of entry of any chemical risk factors for spinal asymmetries. In connection with a chemical risk factor Nachemson anecdotally noted the development of scoliosis in salmon fry at a fish farm who were exposed to water contaminated after the re-painting of a water regulating dam.

Environmental epigenomics and disease susceptibility: Barker and his colleagues and others have shown that the origins of important chronic diseases of adult life may lie in foetal responses to the intrauterine environment and in infants to early postnatal life. Currently, there are British and US medical research projects to gather information on how human genes and environment interact over the years to cause disease; the British project is called Biobank. Another aspect concerns disease susceptibility by spotting gene variants in people who already have specific diseases. Do the suspected risk factors of indoor-chlorinated pools for spinal asymmetries need to be included in such studies? Is there potential for prevention?

In our earlier study we found 61% of the controls taken swimming in the first year of life had vertical spinous process asymmetry. In the subsequent smaller study the incidence even higher (83%).

Conclusions:

The evidence reported in our earlier paper suggests that infants introduced to indoor heated swimming pools in the first year of life show an association with spinal asymmetries including progressive AIS and in controls vertical spinous process asymmetry.

Subject to confirmation of our observations consideration should be given to chemical risk factors, possible portals of entry, environmental epigenomics and disease susceptibility to altered spinal development.

Subsequent controls confirm that the introduction to indoor heated swimming pools in the first year of life is associated with the development of spinal asymmetries.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_II | Pages 225 - 225
1 May 2006
McMaster M Lee AJ Burwell RG
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Background: To our knowledge, there are no publications that have evaluated physical activities in relation to the etiology of AIS other than sport scoliosis (1,2) so we undertook a study to assess the physical activities of patients with progressive AIS from their first year to early teens and compared these with those of a control group.

Methods: All 156 children in this study had to adhere to the following 6 criteria:- born full term, fed well as infants, achieved their milestones, no hospital visits except for sports injuries, no family history of a scoliosis and no back pain (prior to diagnosis in the patient group). We compared 79 consecutive patients (girls 66, boys 13) diagnosed as progressive AIS (62 of whom subsequently had a spinal fusion) with a control group of 77 subjects (girls 66, boys 11) of similar age, gender, race and socioeconomic status. A structured history was obtained from the mother and child of each group average time taken to obtain the history was 47 minutes. Each child was examined for toe touching and vertical symmetry of spinous processes whilst standing. The findings suggest a relation between physical activities or the lack of them and the development of progressive AIS.

Results: There is a significantly increased odds of AIS in those who were introduced to a swimming pool within the first year of life (p=0.001), did not attend gymnastics/ karate classes (p=0.005), did not attend dance classes (girls only, p=0.045), did not have horse riding classes (p=0.003), did not go skating (< 0.001), and who could touch their toes (p=0.011). No association is found with playing football/hockey or regular swimming at the age of 10 years.

Conclusion: Progressive AIS is positively associated with an early introduction to swimming and ability to toe touch. Spinal asymmetry was noted in the controls. AIS is negatively associated with participation in dance, skating, gymnastics/karate and horse riding classes. Is it possible that children who develop AIS have a longstanding proprioception defect which makes them less likely to participate in sporting activities? If so, by encouraging children to participate in sport might we increase their proprioception abilities and make those at risk less likely to develop spinal asymmetry which may progress to a scoliosis requiring surgical correction?


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_II | Pages 231 - 231
1 May 2006
Tsirikos A McMaster M
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Background: Congenital anomalies of the chest wall and Sprengel’s shoulder are often associated with congenital deformities of the spine. It has been suggested that extensive rib fusions on the concavity of a congenital scoliosis may adversely affect progression of the spine deformity, thoracic function and growth of the lungs, which can lead to a thoracic insufficiency syndrome.

Methods: This is a retrospective study of the medical records and spine radiographs of 620 consecutive patients with congenital spine deformities. The rib anomalies were classified into simple and complex and the presence of a Sprengel’s shoulder was recorded.

Subjects: There were 497 patients (80%) with scoliosis, 88 patients (14%) with kyphoscoliosis, and 35 patients with kyphosis (6%). The mean rate of scoliosis deterioration without treatment, age and curve size at surgery was compared for the different types of vertebral abnormalities in patients with and without rib anomalies.

Results: Rib anomalies occurred in 124 patients. The rib anomalies were simple in 97 patients (78%) and complex in 27 (22%). The most common simple rib anomaly (70 patients; 72%) was a fusion of two or three ribs. The most common complex rib anomaly (20 patients; 74%) was a fusion of multiple ribs associated with a large chest wall defect. Rib anomalies were most commonly associated with a congenital scoliosis (116 patients; 93.6%), and much less frequently with a congenital kyphoscoliosis or kyphosis (8 patients). In those patients with a scoliosis, the rib anomalies were simple in 91 patients (78.5%) and complex in 25 patients (21.5%). Eighty-eight of the 124 patients (76%) with rib abnormalities had a scoliosis due to a unilateral unsegmented bar with or without contra-lateral hemivertebrae at the same level, and 8 patients had mixed unclassifiable vertebral anomalies. In contrast, only 17 patients with a scoliosis and rib anomalies had hemivertebrae alone. The rib anomalies were most frequently associated with a thoracic or thoracolumbar scoliosis (107 patients; 92.2%) and occurred on the concavity in 81 patients (70%), convexity in 27 patients (23%), and were bilateral in 8 patients. Sprengel’s deformity occurred in 45 patients; 43 patients with congenital scoliosis (8.6%), and 2 with kyphoscoliosis or kyphosis. A Sprengel’s shoulder occurred most frequently in association with a thoracic scoliosis due to a unilateral failure of vertebral segmentation (28 patients). The elevated shoulder was on the concavity of scoliosis in 26 patients and on the convexity in 16 patients. We compared the mean rate of curve progression without treatment, the age and curve size at spine surgery for the different types of spine deformities in patients with and without rib anomalies either simple or complex and found no significant difference (p> 0.05); the only statistical difference was that the mean age at surgery was higher for patients with a unilateral unsegmented bar without rib anomalies (p=0.005).

Conclusion: Congenital rib anomalies and Sprengel’s shoulder occur most commonly on the concavity of a thoracic or thoracolumbar congenital scoliosis due to a unilateral failure of vertebral segmentation. However, these anomalies do not have an adverse effect on curve size or rate of progression.


Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_II | Pages 119 - 119
1 Feb 2004
Adams C McMaster M McMaster M
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Objective: Idiopathic scoliosis is a complex, three-dimensional deformity. Surgical correction has been assessed by radiographic measurements in the coronal and sagittal planes and vertebral rotation. However the primary concern for the patient is the transverse plane deformity at the skin surface. The purpose of this study was to correlate the surface and radiographic measurements of transverse plane deformity in idiopathic thoracolumbar scoliosis before and after single stage anterior fusion with instrumentation.

Design: A consecutive, prospective study of patients operated upon by a single surgeon.

Subjects: 24 patients (23 female) with idiopathic thoracolumbar scoliosis operated on between 1990 and 1999. Mean age at surgery 14.8 yrs (range 10.9 to 17.5). All had single stage surgery through an anterior thoraco-abdominal approach with anterior release of a mean of 4 discs (range 3 to 6). Anterior instrumentation was inserted using vertebral body screws secured to a single contoured rod with interbody bone grafting using strips of rib autograft.

Outcome measures: All patients were assessed both radiographically and by surface topography using the Integrated Shape Imaging System (ISIS) pre-operatively, post-operatively and during each follow-up visit for a mean 3.1 years (range 1.8–9.1).

Results: Radiographically the mean pre-operative coronal Cobb angle of 49 degrees (range 30 to 74) was reduced to 13 degrees (range 0 to 32) following surgery with a mean 2 degree loss (range −5 to 10) at final follow-up. The Perdriolle rotation was reduced by a mean of 19 degrees (range 5 to 30) with a mean 1 degree loss (range −6 to 6) of correction at final follow-up.

ISIS showed the mean pre-operative Standing Angle of Trunk Inclination (sATI) of 15 degrees (range 7 to 25) was reduced to 5 degrees (range 0 to 15) post-operatively with a further mean improvement of 2 degrees during the follow-up period. The final sATI was within the range of normality for 21 patients (87 percent). Spinal balance in the coronal plane improved from a mean of 24mm to 11mm. Spinal balance in the sagittal plane was unchanged.

Conclusions: Anterior surgery for idiopathic thoracolumbar scoliosis is effective in reducing transverse plane deformity. The Standing Angle of Trunk Inclination is returned to the normal range in 87% of cases. Coronal plane balance is improved by surgery. These corrections occur mainly due to surgery but also continue on follow up (growth).


Orthopaedic Proceedings
Vol. 84-B, Issue SUPP_III | Pages 337 - 337
1 Nov 2002
Adams CI McMaster M McMaster. MJ
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Objective: Surgical correction of late-onset idiopathic scoliosis (AIS) has been shown to be effective in obtaining correction in the frontal and sagittal planes, but is of questionable benefit in reducing the rib hump in the transverse plane The purpose of this study was to assess the effects of double rod and pedicle screw (AO USS) instrumentation on transverse plane asymmetry (on the convex and concave side of the scoliosis) in a single thoracic curve type (King III).

Design: A consecutive, prospectively studied cohort treated by a single surgeon with either a single-stage or two-stage procedure.

Subjects: Sixty-five patients with a King III adolescent idiopathic scoliosis were studied. There were 53 females and 12 males whose mean age at surgery was 14.5 years (range 11.1 to 17.9). A single-stage posterior fusion with instrumentation was performed in 46 patients whose mean Cobb angle at surgery was 56° (range 35 to 84). A two-stage procedure with thoracotomy and anterior spine release by multiple disc excisions (mean 6 levels) combined with internal costoplasty (mean 6 ribs), followed one week later by posterior spinal fusion with instrumentation, was performed in 15 patients whose mean Cobb angle was 78° (range 40 to 92).

Outcome measures: All patients were assessed both radiographically and by Integrated Shape Imaging System (ISIS) surface topography pre-operatively, postoperatively (mean of 14 weeks) and at follow-up visits for a mean 2.7 years (range 1.5–6.1).

Results: There were no non-unions or instrument failures in either group.

Single-stage group: Post-operative improvement in the Cobb angle was a mean 54% with a mean 2° loss in correction at final follow-up. ISIS showed the angle of rib hump elevation (convexity side) was improved by a mean of 2.1° and the angle of rib depression (concavity side) was unchanged. At final follow-up the angle of rib hump elevation had recurred by a mean of 3.6° beyond the original pre-operative value. The angle of rib depression remained unchanged.

Two-stage group: Post-operative improvement in the Cobb angle was a mean 64% with a mean 1° loss in correction at final follow-up. ISIS showed the angle of rib hump elevation (convexity side) was improved by a mean of 6.2° and the angle of rib depression (concavity side) was improved by a mean of 3.5°, producing a more balanced transverse plane. At final follow-up the angle of rib hump elevation only recurred by a mean 2.2°. This was compensated by a further improvement in the angle of rib depression by a mean of 2.5°, producing a further correction to balance the transverse plane.

Conclusions: Single-stage surgery is not effective in improving the transverse plane deformity. Two-stage surgery improves the transverse plane deformity on both the convexity and concavity producing a more balanced spine with further improvement due to an improvement of the rib depression (concave side) during follow-up (growth).


The Journal of Bone & Joint Surgery British Volume
Vol. 76-B, Issue 5 | Pages 773 - 777
1 Sep 1994
McMaster M

Five patients with classical Ehlers-Danlos syndrome developed severe spinal deformities. Two were shown to have type-VI collagen abnormalities. Three had a double structural scoliosis of the thoracic and lumbar regions, one had a single thoracic scoliosis and one had a thoracic kyphosis. The curves first developed before the age of four years, and were not controlled by bracing. Major corrective surgery with posterior fusion was performed at a mean age of 11 years 8 months. Excessive blood loss could be controlled and although wound haematoma and dehiscence were common, they did not provide major problems. The spinal fusions healed satisfactorily.


The Journal of Bone & Joint Surgery British Volume
Vol. 73-B, Issue 6 | Pages 982 - 989
1 Nov 1991
McMaster M

Adolescent idiopathic scoliosis in 152 patients was treated by Luque L-rod instrumentation and early mobilisation without external support. This series was compared with a matched group of 156 patients treated by Harrington instrumentation and immobilised in an underarm jacket for nine months. All the operations in both groups were performed by one surgeon and the patients were followed prospectively for more than two years. Correction of the scoliosis in the frontal plane was similar in both groups. However, the normal sagittal contour was better maintained with Luque rods, especially in the thoracolumbar and lumbar regions, and provided less loss of correction than with Harrington rods. Neither method significantly derotated the scoliosis. All the patients with Luque instrumentation developed a solid fusion despite breakage of the sublaminar wires at one or two levels in 4.9%. There were no major neurological complications with either type of instrumentation.


The Journal of Bone & Joint Surgery British Volume
Vol. 73-B, Issue 5 | Pages 869 - 869
1 Sep 1991
McMaster M


The Journal of Bone & Joint Surgery British Volume
Vol. 69-B, Issue 1 | Pages 20 - 25
1 Jan 1987
McMaster M

Twenty-three patients with severe paralytic thoracolumbar scoliosis due to a myelomeningocele were treated by a two-stage procedure. Before operation the mean scoliosis was 98 degrees: after the first-stage procedure, an anterior spinal fusion and correction with Dwyer instrumentation, this was reduced to a mean of 45 degrees. Approximately two weeks later a posterior spinal fusion with Harrington instrumentation was performed, further reducing the scoliosis to a mean of 29 degrees. The pelvic obliquity also was reduced from a mean of 32 degrees to 6 degrees. Although such management carries risks (one patient died of cardiorespiratory failure after the first stage and one patient was made worse), 21 of the 23 patients had improved posture and function.


The Journal of Bone & Joint Surgery British Volume
Vol. 68-B, Issue 4 | Pages 588 - 595
1 Aug 1986
McMaster M David C

We studied 104 patients with a total of 154 hemivertebrae which had produced scoliotic curves. Of the hemivertebrae 65% were of a fully segmented (non-incarcerated) type, 22% were semi-segmented and 12% were incarcerated. We found that the degree of scoliosis produced depended on four factors: first, the type of the hemivertebra; secondly, its site; thirdly, the number of hemivertebrae and their relationship to each other; and finally, the age of the patient. Semi-segmented and incarcerated hemivertebrae usually do not require treatment. Fully segmented non-incarcerated hemivertebrae may require prophylactic treatment to prevent significant deformity.


The Journal of Bone & Joint Surgery British Volume
Vol. 67-B, Issue 2 | Pages 204 - 210
1 Mar 1985
McMaster M

Fourteen patients with ankylosing spondylitis had an extension osteotomy for severe flexion deformity of the spine. The Smith-Petersen technique was modified by using a compression device which allows a slow, finely controlled closure of the osteotomy, and provides rigid internal fixation. There were no serious neurological complications. All the patients were able to see straight ahead after operation, and all had solid fusion at nine months, having maintained good correction.


The Journal of Bone & Joint Surgery British Volume
Vol. 67-B, Issue 2 | Pages 198 - 203
1 Mar 1985
McMaster M Carey R

Seven patients treated in infancy by a lumbar theco-peritoneal shunt for idiopathic communicating hydrocephalus presented later in childhood after developing a characteristic orthopaedic syndrome. This included a severe, rigid and progressive lumbar hyperlordosis, severe bilateral restriction of straight leg raising and abnormalities of stance and gait. Four of the patients, who had severe hyperlordotic curves of over 90 degrees, required operations to correct their extreme deformity. The recommended method of correction is a three-stage procedure: first, anterior wedge resection osteotomies at several levels in the lumbar spine, then a period of "90-90" femoral traction, and finally a posterior fusion and stabilisation using Harrington instrumentation. The results were good, with few complications.


The Journal of Bone & Joint Surgery British Volume
Vol. 65-B, Issue 5 | Pages 612 - 617
1 Nov 1983
McMaster M

The changing incidence of idiopathic scoliosis in 672 patients who attended the Edinburgh Scoliosis Clinic between 1968 and 1982 inclusive is reported. Of these patients, 144 had infantile, 51 juvenile and 477 adolescent idiopathic scoliosis. Thirty-seven of the infantile curves progressed and 107 resolved. The relative frequency of both progressive and resolving infantile idiopathic scoliosis (given as a percentage of the total number of patients with idiopathic scoliosis) declined from 41.75 per cent in the four years from 1968 to 1971, to four per cent in the three years from 1980 to 1982. It is suggested that infantile idiopathic scoliosis is a preventable deformity and that the position in which the infant is laid may be a causative factor.


The Journal of Bone & Joint Surgery British Volume
Vol. 65-B, Issue 3 | Pages 255 - 258
1 May 1983
Malcolm-Smith N McMaster M

The operative and anaesthesic technique for 44 patients undergoing posterior spinal fusion with Harrington rod instrumentation for idiopathic scoliosis is described. There were two groups of 21 and 23 patients, matched for diagnosis and status before operation. The management of both groups was similar but in one group anaesthesia with induced hypotension was employed, using a mixture of sodium nitroprusside and trimetaphan. The mean blood loss at operation and after operation in this group was significantly lower than in the other group, with a consequent reduction in the transfusion requirement. No adverse sequelae were observed. All patients showed a drop in haemoglobin concentration after operation, despite clinically adequate blood transfusion.


The Journal of Bone & Joint Surgery British Volume
Vol. 65-B, Issue 3 | Pages 247 - 254
1 May 1983
Hefti F McMaster M

Twenty-four children with infantile or juvenile idiopathic scoliosis had their spines corrected and solidly fused posteriorly before the age of eleven years. The growth of the fusion area was then accurately measured for a mean of 4.5 years during the adolescent growth spurt. During this period all longitudinal growth in the posterior elements ceased. The vertebral bodies continued to grow anteriorly, but the thick posterior fusion prevented the development of a lordosis. Initially the anterior growth was accommodated by narrowing of the intervertebral disc spaces, but eventually the vertebral bodies bulged laterally towards the convexity and pivoted on the posterior fusion, giving rise to loss of correction, increasing vertebral rotation and recurrence of the rib hump.


The Journal of Bone & Joint Surgery British Volume
Vol. 62-B, Issue 1 | Pages 59 - 64
1 Feb 1980
McMaster M

The factors during and after operation which influence the development of a solid and stable posterior spinal fusion have been evaluated in 406 patients with scoliosis. The patients were managed in three different ways and all pseudarthroses were accurately detected by exploring the spines six months after the attempted fusion. The incidence of pseudarthroses was significantly lowered from 25 per cent in Group I to 3.8 per cent in Group III by the application of Harrington instrumentation and the use of large amounts of autogenous iliac bone grafts in addition to an interfacetal fusion. Early mobilisation 7 to 10 days after operation and a return to normal activities in a well-moulded underarm plaster jacket did not have a detrimental effect on the development of the fusion or the early maintenance of correction. Those spines with supplementary bone grafts stabilised more rapidly and had better maintenance of correction with only minimal loss after removal of all external support at 10 months.


The Journal of Bone & Joint Surgery British Volume
Vol. 62-B, Issue 1 | Pages 65 - 72
1 Feb 1980
McMaster M Merrick M

Scintigraphy using technetium-labelled methylene diphosphonate was performed on 110 scoliotic patients six months after an attempted fusion and the findings compared with those at exploration to detect the possible sites of pseudarthroses. The majority of patients (65 per cent) had a uniform uptake of isotope over the fused area and all but one had a solid fusion. A second group (35 per cent) had a more patchy uptake and eight of the nine patients with pseudarthroses were in this group. Pseudarthroses were detected as localised areas of increased uptake but there were also a number of false positives and scans that were difficult to interpret due to continuing new bone formation in immature fusions. In those scans performed after one year the pseudarthroses which had been missed were seen more clearly in contrast to the diminished generalised activity in the fused area.


The Journal of Bone & Joint Surgery British Volume
Vol. 61-B, Issue 1 | Pages 36 - 42
1 Feb 1979
McMaster M Macnicol M

Twenty-seven children with progressive infantile idiopathic scoliosis have been reviewed after long-term management. Twenty-two children had single thoracic curves which were diagnosed at an early age and treated in a modified Milwaukee brace until the age of ten years when the spine was corrected and fused. The mean correction after operation was 40 per cent of the initial degree of curvature seen in early childhood before treatment. Solid spinal fusion led to a further moderate loss in correction due to bending of the fusion mass before the spine became stable several years later. Five children had double structural curves and were treated only in a brace. This provided less satisfactory control of these curves but because of the minimal cosmetic deformity, extensive spinal fusion was avoided.


The Journal of Bone & Joint Surgery British Volume
Vol. 60-B, Issue 1 | Pages 82 - 87
1 Feb 1978
McMaster M

The clinical, radiological and pathological features of hallux rigidus affecting nine toes (in seven patients) are described. Characteristic chondral and osteochondral lesions are seen to occur at a specific site on the metatarsal head, and account for the limitation of dorsiflexion but relatively unrestricted plantarflexion typical of hallux rigidus. Radiologically these lesions are often missed because they are mainly cartilaginous and are later obscured by secondary degenerative changes. Histological evidence indicates a traumatic aetiology and a mechanism of injury is suggested.


The Journal of Bone & Joint Surgery British Volume
Vol. 58-B, Issue 3 | Pages 305 - 312
1 Aug 1976
McMaster M James J

A series of 246 patients with scoliosis and attempted fusion had exploration performed six months later in order to detect and treat any pseudarthrosis at an early stage and so prevent subsequent loss of correction. Bilateral or unilateral pseudarthroses occurred in 25 per cent and were of three types--definite, hairline and doubtful. Single unilateral pseudarthroses accounted for 6 per cent and were of little if any clinical significance. The hairline pseudarthroses could not be seen radiologically and were easily missed at exploration. In general the pseudarthroses were least common in the more rigid parts of the spine and in curves which by nature of their aetiology or long duration had become most rigid. Neither the initial severity of the curve nor the degree of correction obtained before the initial attempted fusion had any apparent effect on the incidence. Follow-up for an average of four years has shown that a pseudarthrosis is of little significance with regard to the ultimate result provided it is recognised early and repaired.