Surgical treatment of adolescent idiopathic scoliosis. A comparative analysis

Three hundred and fifty-two patients had a one-stage posterior spinal arthrodesis between 1960 and 1984 using one of four types of instrumentation: a Harrington distraction rod, Harrington distraction and compression rods, Harrington distraction and compression rods with a device for transverse traction, and a Harrington distraction rod with sublaminar wires. All of the patients were female (age-range, eleven to nineteen years), and all had idiopathic scoliosis with a single right or double thoracic curve. The minimum length of follow-up was two years. No significant difference was found among the four groups relative to the amount of correction that was obtained at operation or maintained two years after operation. An average of 13.5 per cent of correction was lost during follow-up in the patients who were treated with postoperative immobilization, and an average of 27 per cent was lost in the patients who were treated with sublaminar wires without immobilization. The use of a straight Harrington rod reduced normal thoracic kyphosis, the addition of a compression rod corrected hyperkyphosis, and the use of a rod with sublaminar wires corrected thoracic hypokyphosis or thoracic lordosis.     

Preoperative Cotrel Traction in Idiopathic Scoliosis

Eighty consecutive patients with idiopathic scoliosis were treated preoperatively with Cotrel traction. Distraction X-rays were taken 2 or 3 days after start of traction and 8-10 days later. In 47 patients equal distraction force was applied in both instances. The force, averaging 28 klb, was measured on the head sling. Cotrel traction reduced the spinal curve 37.5 per cent in the first and 38.9 per cent in the second measurement. The difference is not significant. Preoperative Cotrel traction did not improve the surgical curve correction. Postoperative loss of correction and complication rate was insignificantly reduced compared with the results in a previous study. Cotrel traction does, however, give some indication of the surgical correction achievable.     

Preoperative Cotrel Traction in Idiopathic Scoliosis

Eighty consecutive patients with idiopathic scoliosis were treated preoperatively with Cotrel traction. Distraction X-rays were taken 2 or 3 days after start of traction and 8–10 days later. In 47 patients equal distraction force was applied in both instances. The force, averaging 28 klb, was measured on the head sling. Cotrel traction reduced the spinal curve 37.5 per cent in the first and 38.9 per cent in the second measurement. The difference is not significant. Preoperative Cotrel traction did not improve the surgical curve correction. Postoperative loss of correction and complication rate was insignificantly reduced compared with the results in a previous study. Cotrel traction does, however, give some indication of the surgical correction achievable.     

Use of a bivalved polypropylene orthosis in the postoperative management of idiopathic scoliosis

Forty-four consecutive patients with idiopathic scoliosis treated by posterior spinal fusion and Harrington rod instrumentation were immobilized after surgery with bivalved polypropylene orthoses. Immediate ambulation was allowed, and the patients wore the orthoses for a mean of 5.9 months. Brace removal was permitted with the patient recumbent for sponge bathing. These patients were followed up for a mean of 2.1 years (range, 1.0-4.3 years). The average final correction for all curves was 45%. The average loss of correction was 2.4 degrees (5.3%). Combined distraction and compression instrumentation was found to improve final correction in all curves by 3 degrees (6.2%) as compared with distraction instrumentation alone. There were no pseudarthroses and no rod breakage. Patients enjoyed the benefits of improved personal hygiene, pleasing cosmetic appearance, and increased life-style flexibility, especially swimming, which was not possible with the conventional Risser plaster cast. Use of the polypropylene orthosis offers significant advantages as compared with previous methods of postoperative management: it not only provides consistently good results but is enthusiastically accepted by patients as well.     

Adolescent idiopathic scoliosis treated by Harrington-rod distraction and fusion

One hundred and thirty-three patients who had adolescent idiopathic scoliosis were treated by insertion of a single Harrington distraction rod and spinal fusion. Postoperative immobilization consisted of six months in a below-the-shoulder cast. The mean preoperative curve was 50 degrees, with a range of 30 to 110 degrees. The mean final curve was 35 degrees, with a range of 19 to 63 degrees. There were no neurological injuries and no deep wound infections. Twelve patients required further surgery for complications, all of which were treated successfully. The duration of follow-up ranged from twenty-four to seventy-two months. At final follow-up, all patients had resumed their normal preoperative activities without limitations.     

Preoperative skeletal traction in scoliosis.

To determine the role of preoperative traction in the treatment of spinal curves, ten patients with curves averaging 81 degrees by the Cobb measurement were studied. Each patient was treated in traction by means of a halo or skull tongs and femoral pins for two to three weeks prior to the surgical correction of the scoliosis with instrumentation. Weights were added to the traction apparatus, 1.8 kilograms a day, to a maximum of 18.1 kilograms. Pretraction supine roentgenograms were compared with supine roentgenograms made at three-day intervals throughout the traction period. Preoperative traction resulted in an average improvement of the curves of 34 degrees, or 41 per cent of the initial curve. Most of the correction was obtained within the first week of traction. Further correction during surgery with Harrington instrumentation yielded 13.5 degrees on the average (16 per cent) so that combined correction averaged 47 degrees, or 57 per cent.     

Calculated thoracic volume as related to parameters of scoliosis correction

The parameters in adolescent idiopathic scoliosis correction (longitudinal height gain, coronal and sagittal plane changes) that correlate most closely with an increase in thoracic volume are reported. With pre- and postoperative radiographs of matched patients having straight Harrington distraction rods and contoured Luque rods, coordinates were digitized and the change in thoracic volume was calculated in ten subjects undergoing surgery for right thoracic curves. An increase in volume (7% increase in Harrington rod and 16% among Luque rod patients) was most closely correlated with a change in thoracic kyphosis toward physiologic ranges.     

Decompression and distraction-derotation arthrodesis for degenerative spondylolisthesis

Degenerative spondylolisthesis is the result of chronic disc degeneration with secondary segmental spinal instability. Localized collapse and translational and rotational vertebral subluxation result in low back pain and radiculopathy. Twenty patients with L4-5 degenerative spondylolisthesis having back pain and radiculopathy were treated with a combination of decompressive laminectomy and distraction arthrodesis with short parallel Harrington rods. Patients were ambulated immediately after operation. Minimum follow-up was 2 years (average, 31.6 months). Satisfactory results were obtained in 17 patients (85%). No intraoperative complications occurred. The spondylolisthesis progressed significantly in one patient and the Harrington rods loosened in another. The procedure appears to assist in reducing pathologic motion contributing to low back pain and to relieve traction or compression forces on neural structures by restoring spinal canal anatomy.     

A comparison between spinous process and sublaminar wiring combined with Harrington distraction instrumentation in the management of adolescent idiopathic scoliosis

A study of the efficacy of two techniques of spinal instrumentation on patients with adolescent idiopathic scoliosis was performed. Twenty consecutive patients treated with a single Harrington distraction rod and sublaminar wiring (H-SL) were compared with 20 consecutive patients treated with a single Harrington distraction and spinous process wiring (H-SP). The patients in both groups were similar in age, curve magnitude, curve flexibility, and curve type. The immediate postoperative correction (61% H-SL, 58% H-SP) and follow-up correction (50% H-SL, 49% H-SP) were equivalent. No pseudarthroses were recognized in either group. One patient with H-SL had transient postoperative paresthesias.     

Posterior spinal arthrodesis for congenital scoliosis. An analysis of the cases of two hundred and ninety patients, five to nineteen years old

We analyzed the results of posterior arthrodesis of the spine for congenital scoliosis, with or without Harrington instrumentation, in 290 of 323 patients who were operated on between the ages of five and nineteen years and were followed for two years or more. The length of follow-up averaged six years and ranged from two to twenty-eight years. The average curve before surgery was 55 degrees (range, 13 to 155 degrees), the average curve at correction was 38 degrees (range, 5 to 102 degrees), and the average curve at final follow-up was 44 degrees (range, 5 to 103 degrees). Bending of the fusion mass of more than 10 degrees was seen in forty patients; pseudarthrosis, in twenty; and adding-on of vertebrae with an increase in the curve of more than 10 degrees, in seven patients. There were four deaths, only one of them in the last twenty-five years. One was due to intraoperative cardiac arrest; one, to intraoperative overtransfusion; one, to postoperative overtransfusion; and one, to gastrointestinal bleeding eight months postoperatively while the patient was in a Risser jacket. Two patients became paraplegic due to excessive distraction with the Harrington rod, and two others had a partial cranial-nerve lesion due to halo traction. Based on these results, we concluded that posterior arthrodesis of the spine is satisfactory for most patients with congenital scoliosis. The most common problem was bending of the fusion mass in growing children, which occurred in 14 per cent of the patients. Use of Harrington instruments allowed slightly better correction (36 per cent compared with 28 per cent) but was associated with the only cases of paraplegia and infection in the series.     

Adult idiopathic scoliosis treated with Luque or Harrington rods and sublaminar wiring

We reviewed the results of spinal arthrodesis that was performed, with sublaminar wires that were attached to either double L-shaped Luque rods or to a Harrington rod, in forty-two adults who had idiopathic scoliosis. The minimum length of follow-up was two years; the maximum, five years; and the average, three years. The average scoliosis measured 67 degrees preoperatively, was corrected to 37 degrees at operation, and was 44 degrees at the time of follow-up. The final correction averaged 34 per cent. A single Harrington rod and multiple sublaminar wires were used in thirty-one patients. Eighteen of the thirty-one patients had a posterior arthrodesis only and thirteen, a preliminary anterior arthrodesis followed by a posterior arthrodesis. Eleven patients had instrumentation with double L-shaped Luque rods; six of them had posterior arthrodesis only and five, a preliminary anterior arthrodesis followed by a posterior arthrodesis. One patient had neurological deficit that was related to the operation. Three patients had a pseudarthrosis, which was in the lumbar area in all of them. All three patients had had only a posterior operation. No statistically significant difference in the amount of final correction was demonstrated between the subgroups.     

Coronal decompensation produced by Cotrel-Dubousset "derotation" maneuver for idiopathic right thoracic scoliosis

From 1985 to 1987, 82 patients with idiopathic scoliosis followed 12 to 44 months underwent selective fusion and correction of their right thoracic curves by Cotrel-Dubousset instrumentation using the "derotation" maneuver. Preoperative, postoperative, and follow-up standing anteroposterior roentgenograms of the spine were analyzed. For curves in which there was deviation from the midline (plumb line) and rotation of the lumbar segments, an increased incidence of decompensation was produced after surgery, when posterior Cotrel-Dubousset instrumentation and fusion were carried to the "stable" vertebra with one rod bend and hook alignment on the left sided derotation rod. Previous guidelines established for selective fusion with conventional posterior instrumentation (Harrington or Luque rods) may not be applicable to derotation with Cotrel-Dubousset instrumentation.     

Cotrel Traction, Exercises, Casting in the Treatment of Idiopathic Scoliosis: A Pilot Study and Prospective Randomized Controlled Clinical Trial

A pilot study of ten individuals with adolescent-onset idiopathic scoliosis demonstrated that a week of Cotrel traction and exercises did not improve curve correction obtained by the application of an elongation, derotation, flexion (EDF) cast. There was, however, a significant improvement in lateral bending correction during this period. A prospective, randomized, controlled clinical trial showed that the exercise programme and not the traction was responsible for rendering the spine less rigid.     

Cotrel traction, exercises, casting in the treatment of idiopathic scoliosis. A pilot study and prospective randomized controlled clinical trial.

A pilot study of ten individuals with adolescent-onset idiopathic scoliosis demonstrated that a week of Cotrel traction and exercises did not improve curve correction obtained by the application of an elongation, derotation, flexion (EDF) cast. There was, however, a significant improvement on lateral bending correction during this period. A prospective, randomized, controlled clinical trial showed that the exercise programme and not the traction was responsible for rendering the spine less rigid.     

The progression of idiopathic scoliosis after removal of harrington instrumentation following spinal fusion

We have investigated the affect of removal of Harrington rods in 36 patients who had undergone successful spinal fusion for idiopathic scoliosis. In the curves in which further deterioration had taken place even though fusion had been achieved, there was a small improvement in both major and minor curves in the first six months after removal of the rod, followed by complete stabilisation of the curve. A similar tendency to stabilisation was noticed in the curves which had not shown deterioration. We conclude that regression of a curve which has fused following Harrington rod instrumentation occurs when the rod has not been placed according to optimum biomechanical principles. Removal of the rod then relieves the deforming stresses and allows the spine to stabilise.     

The simultaneous application of an interspinous compressive wire and Harrington distraction rods in the treatment of fracture-dislocation of the thoracic and lumbar spine

During open reduction of thoracolumbar fracture-dislocation, the normal constraints to distraction and lengthening may be ruptured and allow instrumentation to exert deleterious traction of the spinal cord. An interspinous wire across the unstable segment together with a Harrington rod may be used to prevent potential overdistribution of the spinal cord. Thirty-six patients with fracture-dislocation of the thoracolumbar spine were treated by open reduction with Harrington rods and interspinous wiring. Of 15 patients with a partial cord lesion, four made complete recovery, and nine of the remaining 11 became ambulators. Six patients with a complete paraplegia did not improve; 15 patients remained neurologically intact following the procedure. The compressive wire and Harrington rods act in concert and enable correction of kyphosis and restoration of vertebral and discal height while protecting the cord against traction. The technique is safe and does not add to operative time.     

Combined staged anterior and posterior correction and fusion of the spine in scoliosis following poliomyelitis.

The problems with severe forms of scoliosis following poliomyelitis include the associated muscle imbalance, soft tissue contractures and pelvic obliquity. Such deformities militate against optimal correction and maintenance of that correction and their treatment is often marred by pseudarthroses. Seventeen patients with an average curve of 93 degrees have been treated and followed for up to 38 months. Preliminary traction was used in 8 patients, then a staged anterior and posterior correction and fusion was done, using Dwyer's instrumentation of the major curve in all and a Harrington rod to supplement the posterior fusion in eleven patients. With this technique the major curve was corrected by 80 per cent with an average 2 per cent loss over 18 months. No pseudarthroses were seen when the Harrington rod was used. Great care must be taken if halo-pelvic traction is to be used for patients with pelvic obliquity, for preliminary correction halo-femoral traction will often be adequate. In the more severe forms of paralytic scoliosis a combined staged anterior and posterior correction and fusion should be considered if the aim is maximal correction of the scoliosis and avoidance of pseudarthroses.     

Acquired spondylolisthesis following scoliosis surgery. A case report

The association between scoliosis and spondylolisthesis is well documented; however, spondylolisthesis following a posterior spinal fusion with Harrington rod instrumentation for idiopathic scoliosis has not been previously reported. Internal fixation of the spine with metal rods and fusion for scoliosis produces a stress concentration at the immediately adjacent levels. This, combined with other factors that may cause failure of the neural arch, can lead to a traumatic spondylolisthesis. In an 11-year-old boy, localized pain and impending listhesis indicated that the instrumentation should be removed and an arthrodesis completed.     

Analysis of lumbar lordosis in posterior spine fusions for idiopathic scoliosis

Previous reports are inconclusive regarding changes in the lumbar region after Harrington rod distraction and posterior spinal fusion for idiopathic scoliosis. The purpose of this study was to evaluate the effects of spinal fusion on the lumbar region, particularly the overall lumbar lordosis, the lumbar lordosis in and below the fused segment, the sacro-horizontal angle, and the sagittal plane alignment of the spine. Sixty-six patients under 21 years of age with idiopathic scoliosis who had spine fusion extending to the lumbar vertebrae using only Harrington distraction instrumentation were evaluated. The total lordosis, sacro-horizontal angle, and sagittal plane alignment remained relatively constant. The lordosis within the fusion decreased, and lordosis caudal to the fusion, including the last fused vertebra, increased as the lower hook placement site moved caudally.     

Evaluation of spinous process wire fixation with Harrington instrumentation for idiopathic scoliosis

A modification of the technique of Harrington instrumentation for idiopathic scoliosis utilizes segmental spinous process wiring. The purpose of this study is to contrast and compare two populations of surgically treated patients with idiopathic scoliosis: one group with a single Harrington distraction rod and the other group with the addition of spinous process wiring. Of 252 consecutive patients between 1971 and 1987, 215 were retrievable, with an average clinical follow-up of 2.2 years. Curves were analyzed by location and patient age. Patients treated with spinous process wires were braced, those without were casted. No significant difference in terms of percent correction with time was evident between the two treatment groups. The complication rate (11.0%) and pseudarthrosis rate (4.0%) were the same in both wired and standard groups. The more rigid adult curves resulted in less correction and greater complications than adolescent curves. Spinous process wiring seemed to protect against upper hook cut-out. There were no deaths or paraplegias. Patients surgically treated with the wire modification enjoyed greater comfort with the removable brace, and curve correction was equal to that obtained in patients treated with the standard technique and post-op casting.