JBJS | Radiographic Results of Arthrodesis with Cotrel-Dubousset Instrumentation for the Treatment of Adolescent Idiopathic Scoliosis. A Five to Ten-Year Follow-up Study*†

The Journal of Bone & Joint Surgery, Volume 80, Issue 6

Articles | June 01, 1998

Radiographic Results of Arthrodesis with Cotrel-Dubousset Instrumentation for the Treatment of Adolescent Idiopathic Scoliosis. A Five to Ten-Year Follow-up Study*†

LAWRENCE G. LENKE, M.D.‡; KEITH H. BRIDWELL, M.D.‡; KATHY BLANKE, R.N.‡; CHRISTY BALDUS, L.P.N.‡; JOETTA WESTON, R.N.‡, ST. LOUIS, MISSOURI

View Disclosures and Other Information

Investigation performed at the Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis

The Journal of Bone & Joint Surgery. 1998; 80:807-14

5 Recommendations (Recommend) | 3 Comments | Saved by 3 Users Save Case

text A A A

Abstract

We evaluated the radiographic results of posterior spinal arthrodesis with use of Cotrel-Dubousset instrumentation in seventy-six patients who had adolescent idiopathic scoliosis. At an average of six years (range, five to ten years) postoperatively, the fusion appeared to be solid in all patients. Comparison of radiographs that had been made immediately postoperatively with those that had been made at the time of the latest follow-up showed that no patient had lost any correction in the coronal plane at the levels with instrumentation and seventy-five had had no change in the thoracic or lumbar sagittal alignment at the levels with or without instrumentation. In the remaining patient, a kyphosis had developed at the junction of the segments with instrumentation and those without instrumentation, necessitating additional operative treatment. Sixty-three patients completed a questionnaire for assessment of the clinical status. Their responses were favorable with regard to function, cosmetic appearance, and general satisfaction with the operative result. Twenty-four (38 per cent) of the sixty-three patients reported occasional pain in the spine that did not interfere with work or school activities. Sixty-two patients stated that, given the hypothetical situation of reverting to the preoperative status, they would have the operation again.

Figures in this Article

Introduction

Introduction | Materials and Methods | Results | Discussion | References

The concept that idiopathic scoliosis is a three-dimensional deformity is gaining support and is influencing the development of newer forms of instrumentation. Attempts are currently being made to correct coronal, sagittal, and axial malalignment with one operation. Cotrel-Dubousset instrumentation was designed to provide bilateral segmental fixation of the spine and selective distraction and compression at different levels as well as to improve the alignment of the spine in the coronal, the sagittal, and possibly the axial plane¹². Since its introduction in 1984, this instrumentation system has become an established means for attaining segmental spinal fixation, and it frequently is used for the operative treatment of adolescent idiopathic scoliosis^28,44,45. The stable fixation that is provided by the instrumentation has reduced the need for postoperative immobilization⁴⁵.

The early results of correction in the coronal plane have been similar to or slightly better than those reported with use of Harrington or Luque instrumentation for the treatment of thoracic curves^{28,30,32,43,46}. Initially, the axial realignment that was attained with use of Cotrel-Dubousset instrumentation was believed to be far superior to that achieved with Harrington or Luque instrumentation; however, recent reports have suggested that the degree of spinal derotation is minimum^{1,2,22,23,26,30}. Cotrel-Dubousset instrumentation is believed to enhance thoracic kyphosis and to preserve or improve segmental thoracolumbar and lumbar sagittal alignment^6,28. The use of Harrington distraction instrumentation in the middle and caudad lumbar vertebrae tends to reduce lumbar lordosis, resulting in flatback syndrome^3,8,14,49.

In our preliminary follow-up study²⁸, performed at a minimum of two years (average, three years; maximum, five years) after use of Cotrel-Dubousset instrumentation for the treatment of adolescent idiopathic scoliosis, coronal decompensation was seen in patients who had a type-II curve as classified with the system of King et al.^24,25. The major advantages of the Cotrel-Dubousset system were stable fixation of the spine and improved control in the sagittal plane. We subsequently performed a five to ten-year follow-up evaluation to determine if there had been any radiographic loss of correction in the coronal or sagittal plane secondary to pseudarthrosis or failure of the instrumentation within the area of the spine that was included in the arthrodesis and to assess whether the segments that were cephalad to the site of the arthrodesis and especially those that were caudad to it showed any evidence of disc degeneration. Function, cosmetic appearance, pain, and overall satisfaction with the result of the procedure also were assessed, with use of a questionnaire completed by the patients. We believe that this information will help investigators to determine whether Cotrel-Dubousset instrumentation and other segmental spinal instrumentation systems are better methods for stabilizing and correcting triplanar deformities than non-segmental instrumentation.

*No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. No funds were received in support of this study.

†Read at the Annual Meetings of the Scoliosis Research Society, Asheville, North Carolina, September 15, 1995, and the North American Spine Society, Washington, D.C., October 22, 1995.

‡Department of Orthopaedic Surgery, Washington University School of Medicine, One Barnes Hospital Plaza, Suite 11300, West Pavilion, St. Louis, Missouri 63110. Please address requests for reprints to Dr. Lenke.

*No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. No funds were received in support of this study.

†Read at the Annual Meetings of the Scoliosis Research Society, Asheville, North Carolina, September 15, 1995, and the North American Spine Society, Washington, D.C., October 22, 1995.

View Larger

TABLE I CORONAL PARAMETERS

*At an average of three years (range, two to five years)²⁸. †At an average of six years (range, five to ten years).

	Primary Cobb Angle³⁴(cm)	Apical Vertebral Translation (cm)	Vertebral Tilt of Most Caudad Level with Instrumentation (degrees)	Translation of Most Caudad Level with Instrumentation (cm)
Preop.	53 (40—138)	5 (1—15)	18 (0—46)	1.3 (0—5)
Follow-up
Preliminary*	28 (5—55)	2 (0—5)	7 (0—20)	0.9 (0—4)
Latest†	29 (5—57)	2 (0—6)	6 (0—22)	0.7 (0—4)

Add to My JBJS

TABLE I CORONAL PARAMETERS

*At an average of three years (range, two to five years)²⁸. †At an average of six years (range, five to ten years).

	Primary Cobb Angle³⁴(cm)	Apical Vertebral Translation (cm)	Vertebral Tilt of Most Caudad Level with Instrumentation (degrees)	Translation of Most Caudad Level with Instrumentation (cm)
Preop.	53 (40—138)	5 (1—15)	18 (0—46)	1.3 (0—5)
Follow-up
Preliminary*	28 (5—55)	2 (0—5)	7 (0—20)	0.9 (0—4)
Latest†	29 (5—57)	2 (0—6)	6 (0—22)	0.7 (0—4)

View Larger

TABLE II SAGITTAL PARAMETERS

*At an average of three years (range, two to five years). †At an average of six years (range, five to ten years).

	Sagittal Alignment (degrees)
	T5—T12	T10—T12	T12-Most Caudad Level with Instrumentation	L1—L5	T12-Sacrum
Preop.	+18 (-15 to +62)	+4 (-19 to +26)	-6 (-40 to +9)	-42 (-6 to -73)	-50 (0 to -87)
Follow-up
Preliminary*	+23 (+6 to +68)	+7 (-7 to +28)	-6 (-42 to +15)	-46 (-15 to -75)	-59 (-30 to -84)
Latest†	+26 (+3 to +65)	+6 (-4 to +20)	-5 (-40 to +5)	-49 (-16 to -75)	-60 (-20 to -85)

Add to My JBJS

TABLE II SAGITTAL PARAMETERS

*At an average of three years (range, two to five years). †At an average of six years (range, five to ten years).

	Sagittal Alignment (degrees)
	T5—T12	T10—T12	T12-Most Caudad Level with Instrumentation	L1—L5	T12-Sacrum
Preop.	+18 (-15 to +62)	+4 (-19 to +26)	-6 (-40 to +9)	-42 (-6 to -73)	-50 (0 to -87)
Follow-up
Preliminary*	+23 (+6 to +68)	+7 (-7 to +28)	-6 (-42 to +15)	-46 (-15 to -75)	-59 (-30 to -84)
Latest†	+26 (+3 to +65)	+6 (-4 to +20)	-5 (-40 to +5)	-49 (-16 to -75)	-60 (-20 to -85)

View Large | Download Slide(.ppt)
Add to My JBJS

Figs. 1-A through 1-F: Radiographs of a female patient who had a 138-degree type-IV right thoracic curve (the largest curve in the series). Fig. 1-A: Preoperative anteroposterior radiograph, made when the patient was fourteen years and nine months old, showing the 138-degree thoracic curve and a 68-degree lumbar curve.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-B: Preoperative radiograph made in the sagittal plane. The severe three-dimensional deformity made it difficult to visualize and measure the curve.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-C: Anteroposterior radiograph, made two years postoperatively, showing a 42-degree thoracic curve and a 15-degree lumbar curve.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-D: Anteroposterior radiograph, made five years and three months postoperatively, when the patient was twenty years and one month old, showing a 45-degree thoracic curve and a 19-degree lumbar curve. The correction has been maintained.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-E: Lateral radiograph, made two years postoperatively, showing a -68-degree sagittal alignment (68 degrees of lumbar lordosis).

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-F: Lateral radiograph, made five years and three months postoperatively, showing 70 degrees of lumbar lordosis. The correction has been maintained.

Materials and Methods

Introduction | Materials and Methods | Results | Discussion | References

The study consisted of seventy-six consecutive patients who had had an arthrodesis of the spine with use of Cotrel-Dubousset instrumentation, between 1985 and 1988, for the treatment of adolescent idiopathic scoliosis. The patients were followed for an average of six years (range, five to ten years). These patients were part of the group of ninety-five patients who had been followed for a minimum of two years (average, three years; maximum, five years) in our previous study²⁸.

Multiple attempts were made to contact all patients in order to obtain radiographs. However, there were difficulties due to the social mobility of individuals in the United States. Some of the female patients had married and changed their last names, many older teenagers and young adults had left home either for educational or employment reasons, and some patients who lived far away could not afford the expense of traveling to our facility.

The average age of the patients at the time of the latest follow-up evaluation was twenty years and six months (range, sixteen years and four months to twenty-seven years and nine months). All of the operations had been performed by the senior one of us (K. H. B.). To avoid bias and to verify the data objectively, the radiographs were reviewed by another of us (L. G. L.), who had not been involved in the initial operative management of the patients.

Anteroposterior radiographs, lateral radiographs, and anteroposterior radiographs with lateral bending had been made preoperatively. For the present study, we reviewed the anteroposterior and lateral radiographs of the entire spine that had been made (with the patient standing) on cassettes that were thirty-six inches (91.44 centimeters) long, immediately after the procedure, at the preliminary follow-up evaluation (at a minimum of two years and an average of three years), and at the latest follow-up evaluation (at a minimum of five years and an average of six years). All coronal curves were measured with the Cobb method³⁴, as was the sagittal alignment between the fifth and twelfth thoracic vertebrae, the tenth and twelfth thoracic vertebrae, the twelfth thoracic vertebra and the most caudad vertebra with instrumentation, the first and fifth lumbar vertebrae, and the twelfth thoracic and first sacral vertebrae. The degree of angulation of the disc immediately inferior to the most caudad vertebra with instrumentation also was measured.

To measure alignment of the spine, a vertical line was drawn from the base of the spinous process of the seventh cervical vertebra to the sacrum, and the deviation of that line from the midline of the sacrum was recorded in centimeters. Apical vertebral translation was defined as the distance, in centimeters, between the plumbline and the mid-portion of the vertebral body at the apex of the curve. Apical vertebral rotation was defined as rotation of the apical vertebra as measured with the technique of Nash and Moe³⁵. Tilt of the most caudad vertebra with instrumentation was measured, in degrees, from the horizontal, and translation of the most caudad vertebra with instrumentation was measured, in centimeters, as the distance from the central sacral line to the mid-portion of the most caudad vertebral body with instrumentation.

The preoperative curve patterns were determined on the basis of the classification system of King et al.^24,25. Fourteen patients had a type-II curve; twenty-seven, a type-III curve; eleven, a type-III 1/2 or type-IV curve; seven, a type-V curve; eleven, a double-major curve; three, a thoracolumbar-lumbar curve; and three, a left thoracic curve. There were few thoracolumbar-lumbar curves in this study group because we have treated (and continue to treat) such curves with anterior spinal arthrodesis and instrumentation.

Postoperatively, a custom-molded thoracolumbosacral orthosis was worn by fourteen patients: three who had had a thoracoplasty wore the orthosis for comfort, two who had a history of grand mal seizures wore it to prevent displacement of the hooks, eight wore it because they were non-compliant with restrictions in activity, and one who had type-II scoliosis wore it to prevent progression of a lumbar curve.

A clinical assessment questionnaire consisting of fifty-seven questions was completed at the latest follow-up examination by sixty-three patients who had been followed for a minimum of five years. The questionnaire was developed by all five of us, and the data were obtained postoperatively by three scoliosis nurse-clinicians (K. B., C. B., and J. W.) who had never met the patients preoperatively. The questionnaire was used to assess function, cosmetic appearance, pain related to the spine, and the patient's general satisfaction with the result of the operation. This instrument was based on the criteria used by Dickson and Harrington to assess the results after arthrodesis with Harrington instrumentation in adults who had scoliosis¹⁶ as well as on the criteria that were listed in a more recent, twenty-four-question form developed by Gorup et al. and the Scoliosis Research Society²¹ to assess the same four parameters as were assessed by our instrument. A question that was considered to have great relevance was whether or not the patient, given the same preoperative situation and choices, would have the operation again. The patient could select one of four possible answers to this question: definitely yes, probably, not sure, or definitely not.

All seventy-six patients were examined by an attending orthopaedic surgeon (L. G. L. or K. H. B.) at the time of the latest evaluation. Patients were questioned about any problems related to the back or the lower extremities. The physical examination also was performed to document any concerns about the incisional scar, coronal or sagittal imbalance, or alignment of the shoulder and trunk that were not revealed by the radiographs or the questionnaire.

Results

Introduction | Materials and Methods | Results | Discussion | References

No patient had a loss of correction in the coronal or sagittal plane, between the preliminary follow-up and latest follow-up evaluations, at the levels of the spine with instrumentation. The average coronal curve, as measured on the preoperative, preliminary follow-up²⁸, and latest follow-up radiographs, was 53 degrees (range, 40 to 138 degrees), 28 degrees (range, 5 to 55 degrees), and 29 degrees (range, 5 to 57 degrees), respectively. The average deviation of the coronal plumbline from the midline was 1.3 centimeters (range, zero to five centimeters), 0.9 centimeter (range, zero to four centimeters), and 0.7 centimeter (range, zero to four centimeters). The average apical vertebral translation was five centimeters (range, one to fifteen centimeters), two centimeters (range, zero to five centimeters), and two centimeters (range, zero to six centimeters). The average tilt of the most caudad segment with instrumentation was 18 degrees (range, 0 to 46 degrees), 7 degrees (range, 0 to 20 degrees), and 6 degrees (range, 0 to 22 degrees), respectively (Table I).

In the sagittal plane, the average thoracic kyphosis, from the fifth to the twelfth thoracic vertebra, as measured on the preoperative, preliminary follow-up²⁸, and latest follow-up radiographs, was +18 degrees (range, -15 to +62 degrees), +23 degrees (range, +6 to +58 degrees), and +26 degrees (range, +3 to +65 degrees), respectively. The average sagittal alignment at the thoracolumbar junction (from the tenth to the twelfth thoracic vertebra) was +4 degrees (range, -19 to +26 degrees), +7 degrees (range, -7 to +28 degrees), and +6 degrees (range, -4 to +20 degrees). The average cephalad lumbar alignment, as measured from the twelfth thoracic vertebra to the most caudad vertebra with instrumentation, was -6 degrees (range, -40 to +9 degrees), -6 degrees (range, -42 to +15 degrees), and -5 degrees (range, -40 to +5 degrees). The average lumbar lordosis between the first and fifth lumbar vertebrae was 42 degrees (range, 6 to 73 degrees), 46 degrees (range, 15 to 75 degrees), and 49 degrees (range, 16 to 75 degrees). The average total lumbar lordosis, as measured from the twelfth thoracic vertebra to the sacrum, was -50 degrees (range, 0 to 87 degrees), 59 degrees (range, 30 to 84 degrees), and 60 degrees (range, 20 to 85 degrees) (Table II).

The average angulation of the disc immediately inferior to the most caudad vertebra with instrumentation, as measured with the Cobb technique³⁴, was -5 degrees (range, 0 to -22 degrees), -6 degrees (range, 0 to -25 degrees), and -5 degrees (range, 0 to 22 degrees).

The coronal and sagittal alignment appeared unchanged in seventy-five of the seventy-six patients when the radiographs made at the preliminary follow-up evaluation²⁸ were compared with those made at the latest follow-up evaluation. For example, a fourteen-year and nine-month-old girl had a severe right thoracic curve of 138 degrees and a compensatory left lumbar curve of 68 degrees (Fig. 1-A). The severe three-dimensional deformity made accurate measurement of the sagittal alignment difficult (Fig. 1-B). An anterior release and osteotomies of the apical vertebrae were performed, followed by use of traction for approximately two weeks postoperatively. A posterior arthrodesis from the third thoracic to the third lumbar vertebra subsequently was performed with use of Cotrel-Dubousset instrumentation and bone-grafting. Two years postoperatively, anteroposterior radiographs showed correction of the thoracic curve to 42 degrees and correction of the lumbar curve to 15 degrees (Figs. 1-C and 1-E). At the latest follow-up evaluation, five years and three months postoperatively, anteroposterior radiographs showed a 45-degree thoracic curve and a 19-degree lumbar curve (Figs. 1-D and 1-F). Lateral radiographs showed a lumbar lordosis that was 68 degrees at two years and 70 degrees at the latest follow-up evaluation. The correction had essentially been maintained over the follow-up period.

There were no failures of the instrumentation, such as breakage of rods, dislodgment or disengagement of hooks, or bending or breakage of screws, that were indicative of a pseudarthrosis. The patients were not routinely evaluated for the presence of a pseudarthrosis with use of oblique radiographs, tomograms, or bone scans. Some patients felt that the instrumentation was somewhat prominent, mainly in the cephalad and middle portions of the thoracic spine, but they did not consider removal of the hardware as the discomfort was tolerable.

Complications

As reported in our preliminary follow-up study²⁸, five patients needed a reoperation within the first year after the operation. One patient had incorrect placement of the hooks in the lumbar spine with subsequent loss of correction and development of a symptomatic pseudarthrosis in the mid-portion of the lumbar spine. A second posterior arthrodesis was done, and a solid fusion was obtained. Three patients who had a type-II or III^24,25 thoracic curve had evidence of coronal decompensation within three months after the initial operation. Two of these patients, who had had a selective thoracic arthrodesis to the first lumbar vertebra, had extension of the arthrodesis to the fourth lumbar vertebra. This resulted in a balanced, well aligned spine both clinically and radiographically. The third patient, who was eleven years and six months old at the time of an arthrodesis of the thoracic curve only, had progression of the lumbar curve with continued growth. One year after the first operation, she had an arthrodesis of the lumbar spine with use of Cotrel-Dubousset instrumentation. Two additional patients who had a type-II or III^24,25 thoracic curve also had coronal decompensation, but they did not need operative intervention as the decompensation resolved spontaneously with some loss of correction of the thoracic curve.

Since the time of the preliminary follow-up study²⁸, only one patient needed an additional operation. This patient, who initially had had an arthrodesis from the eleventh thoracic to the fourth lumbar vertebra for the treatment of a thoracolumbar scoliosis, needed correction of a progressive thoracic kyphosis cephalad to the level of the instrumentation.

Discussion

Introduction | Materials and Methods | Results | Discussion | References

Cotrel-Dubousset instrumentation and other forms of segmental spinal fixation are used widely in the operative treatment of adolescent idiopathic scoliosis^{4,5,12,13,15,29,38-42,47,51}. The longest reported follow-up thus far, to our knowledge, has been two years^28,43. The early use of these systems was associated with numerous complications^{7,27,28,33,39,50}. These problems were the result of a failure to identify appropriate placement of the hooks⁴³, failure to pay strict attention preoperatively to the deformity in the sagittal plane⁶, and early postoperative coronal decompensation^{7,27,33,39,48}. The latter problem is uncommon with use of Harrington instrumentation, and many theories for its etiology have been proposed. We found that it was due to improper identification of type-II curves that could be treated successfully with selective thoracic arthrodesis and to difficulty in identifying the sequence of instrumentation that would result in a balanced lumbar spine caudad to the thoracic levels with instrumentation when segmental spinal instrumentation was used^7,27,28. Some of these problems can be avoided by limiting the degree of correction of the thoracic curve, avoiding a full 90-degree rod-rotation maneuver, and relying more on selective compression and distraction forces and use of a three-rod technique to correct larger and stiffer thoracic curves. In addition, reversal of the hooks on the left (concave) rod between the neutral and stable vertebrae and reversal of the bend in the rod, thereby creating a thoracolumbar lordosis, has helped to maintain better coronal and sagittal balance.

By adhering to the principles of proper identification of the curve and accurate placement of the hooks and rods, we were able to prevent postoperative coronal decompensation in the last forty-two patients with a type-II curve whom we have managed operatively since 1988. Also, we did not find evidence of late decompensation at the latest follow-up evaluation of patients with a type-II curve that had been treated with a selective thoracic arthrodesis. There was no measurable loss of correction between the preliminary follow-up²⁸ and latest follow-up evaluations. There was a 5-degree loss of correction in the coronal plane at the preliminary follow-up evaluation²⁸. Although there is no way to be certain that all of these patients had a solid fusion at the levels with instrumentation, the absence of overt clinical and radiographic signs of pseudarthrosis, failure of the instrumentation, loss of correction, or chronic, localized axial pain at these levels supports the belief that the fusion was solid. While it is often impractical, if not impossible, to document radiographically a solid fusion mass after arthrodesis of the spine in patients with scoliosis because of the amount and location of the instrumentation, we are certainly more confident that the fusion was solid at the time of the five to ten-year follow-up than we were at the time of the two to five-year follow-up.

None of the patients who had an arthrodesis to the middle or caudad level of the lumbar spine had problems that necessitated an additional operation to extend the fusion more distally. This may be due to the better control of the thoracolumbar and lumbar sagittal alignment that was attained and maintained with use of the Cotrel-Dubousset instrumentation; however, a ten to twenty-year follow-up is needed to confirm this hypothesis. It is promising to note that the parameters of sagittal alignment have been maintained over the course of time, not only for the patients who had thoracic kyphosis but also for those who had lumbar lordosis. Typically, lumbar sagittal alignment from the twelfth thoracic vertebra to the most caudad vertebra with instrumentation or to the sacrum was maintained over the follow-up period (Table II).

There was no evidence of premature disc degeneration—that is, no changes in disc height or segmental angulation on the radiographs—immediately caudad to the segments with instrumentation. Ideally, early disc degeneration can be detected on magnetic resonance images; however, images for these patients would have been blurred or altered because of metal artifacts. A longer follow-up is essential to determine if the segments caudad to the arthrodesis undergo accelerated degenerative changes, but our results thus far are encouraging. At the very least, our patients appeared to be free of the lumbar flatback syndrome that has been reported with use of Harrington distraction instrumentation in the lumbar spine^{3,9-11,14,18,49}.

None of our patients had a late infection that necessitated removal of the instrumentation. (Richards reported this problem³⁷.) Similarly, no patient had irritation of tissue caused by fretting corrosion of particulate debris from the knurled rod-hook construct. All of our patients received a first-generation cephalosporin prophylactically before the operation.

As mentioned, at the time of the latest follow-up evaluation we assessed function, cosmetic appearance, pain in the spine, and overall satisfaction with the result of the procedure. Admittedly, we did not have preoperative patient-generated data to use for comparison as the importance of prospective clinical assessment was not fully appreciated at the time that these procedures were performed (between 1985 and 1988)^13,31. It is only subsequently that the value of such data has been realized^19,20. However, although the questionnaire has not been validated and there were no preoperative data, we thought that it would be useful to include the information that we obtained with this instrument. We were unable to obtain responses from all seventy-six patients who were studied radiographically, but we evaluated the information obtained from the questionnaires that were completed by sixty-three patients (83 per cent).

The patients' responses to questions about function, cosmetic appearance, and overall satisfaction with the result of the operation were favorable. Of the sixty-three patients who responded, fifty-eight (92 per cent) gave positive responses in the function category and fifty-nine (94 per cent) gave such responses in the cosmetic-appearance category of the instrument. Similarly, sixty-one patients (97 per cent) gave positive responses to questions pertaining to their satisfaction with the result of the operation. In response to the important hypothetical question as to whether, if presented with the same preoperative problem, the patient would consider having the operation again, forty-eight patients (76 per cent) stated that they definitely would do so, fourteen (22 per cent) stated that they probably would do so, and one patient (2 per cent) was not sure. It is important to continue to follow these patients to see if these positive responses are maintained over the next ten to twenty years.

Only twenty-four (38 per cent) of sixty-three patients gave positive responses to questions about whether they had pain. We did not specifically investigate the locations of the various areas of pain in the spine as the questions were fairly generalized. In addition, we do not know how many of the patients had had back pain preoperatively. It is well known that American adults have a high prevalence of back pain, which appears to be multifactorial^16,17. We also do not know how a group of individuals who did not have spinal deformity would respond to the pain category of the questionnaire³⁶. None of our patients had incapacitating back pain that prevented them from attending work or school on a daily basis. We were unable to find any relationship between arthrodesis to the third or fourth lumbar vertebra and the responses to the questions about pain, and we also did not find any evidence of progressive disc degeneration caudad to the site of the arthrodesis. In contrast, Cochran et al. reported increasing disc degeneration after arthrodesis in the middle and caudad portions of the lumbar spine with use of Harrington instrumentation¹⁰.

In summary, the five to ten-year radiographic results after operative treatment with Cotrel-Dubousset instrumentation in patients who had adolescent idiopathic scoliosis demonstrated no pseudarthroses, failures of instrumentation, or changes in the overall coronal or sagittal alignment of the spine at the levels with or without instrumentation. A clinical assessment questionnaire used only at the latest follow-up evaluation indicated a high level of patient satisfaction. These results are encouraging; however, a longer (ten to twenty-year) duration of follow-up is necessary to determine whether they will be maintained.

References

Introduction | Materials and Methods | Results | Discussion | References

Aaro, S., and Dahlborn, M.: Estimation of vertebral rotation and the spinal and rib cage deformity in scoliosis by computer tomography. Spine,6: 460-467, 1981.6460 1981 [PubMed]

Aaro, S., and Dahlborn, M.: The effect of Harrington instrumentation on the longitudinal axis rotation of the apical vertebra and on the spinal and rib-cage deformity in idiopathic scoliosis studied by computer tomography. Spine,7: 456-462, 1982.7456 1982 [PubMed]

Aaro, S., and Ohlen, G.: The effect of Harrington instrumentation on the sagittal configuration and mobility of the spine in scoliosis. Spine,8: 570-575, 1983.8570 1983 [PubMed]

Bergoin, M.; Bollini, G.; Hornung, H.; Tallet, J. M.; and Gennari, J. M.: Is the Cotrel-Dubousset really universal in the surgical treatment of idiopathic scoliosis?. J. Pediat. Orthop.,8: 45-48, 1988.845 1988

Birch, J. G.; Herring, J. A.; Roach, J. W.; and Johnston, C. E.: Cotrel-Dubousset instrumentation in idiopathic scoliosis. A preliminary report. Clin. Orthop.,227: 24-29, 1988.22724 1988 [PubMed]

Bridwell, K. H.; Betz, R.; Capelli, A. M.; Huss, G.; and Harvey, C.: Sagittal plane analysis in idiopathic scoliosis patients treated with Cotrel-Dubousset instrumentation. Spine,15: 644-649, 1990.15644 1990 [PubMed]

Bridwell, K. H.; McAllister, J. W.; Betz, R. R.; Huss, G.; Clancy, M.; and Schoenecker, P. L.: Coronal decompensation produced by Cotrel-Dubousset "derotation" maneuver for idiopathic right thoracic scoliosis. Spine,16: 769-777, 1991.16769 1991 [PubMed]

Carman, D. L.; Browne, R. H.; and Birch, J. G.: Measurement of scoliosis and kyphosis radiographs. Intraobserver and interobserver variation. J. Bone and Joint Surg.,72-A: 328-333, March 1990.72-A328 1990

Casey, M. P.; Asher, M. A.; Jacobs, R. R.; and Orrick, J. M.: The effect of Harrington rod contouring on lumbar lordosis. Spine,12: 750-753, 1987.12750 1987 [PubMed]

Cochran, T.; Irstam, L.; and Nachemson, A.: Long-term anatomic and functional changes in patients with adolescent idiopathic scoliosis treated by Harrington rod fusion. Spine,8: 576-584, 1983.8576 1983 [PubMed]

Connolly, P. J.; Von Schroeder, H. P.; Johnson, G. E.; and Kostuik, J. P.: Adolescent idiopathic scoliosis. Long-term effect of instrumentation extending to the lumbar spine. J. Bone and Joint Surg.,77-A: 1210-1216, Aug. 1995.77-A1210 1995

Cotrel, Y., and Dubousset, J.: Nouvelle technique d'ostéosynthèse rachidienne segmentaire par voie postérieure. Rev. chir. orthop.,70: 489-494, 1984.70489 1984 [PubMed]

Cotrel, Y.; Dubousset, J.; and Guillaumat, M.: New universal instrumentation in spinal surgery. Clin. Orthop.,227: 10-23, 1988.22710 1988 [PubMed]

Davies, A. G., and McMaster, M. J.: The effect of Luque-rod instrumentation on the sagittal contour of the lumbosacral spine in adolescent idiopathic scoliosis and the preservation of a physiologic lumbar lordosis. Spine,17: 112-115, 1992.17112 1992 [PubMed]

Denis, F.: Cotrel-Dubousset instrumentation in the treatment of idiopathic scoliosis. Orthop. Clin. North America,19: 291-311, 1988.19291 1988

Dickson, J. H., and Harrington, P. R.: The evolution of the Harrington instrumentation technique in scoliosis. J. Bone and Joint Surg.,55-A: 993-1002, July 1973.55-A993 1973

Frymoyer, J. W.; Pope, M. H.; Clements, J. H.; Wilder, D. G.; MacPherson, B.; and Ashikaga, T.: Risk factors in low-back pain. An epidemiological survey. J. Bone and Joint Surg.,65-A: 213-218, Feb. 1983.65-A213 1983

Gaines, R. W., and Leatherman, K. D.: Benefits of the Harrington compression system in lumbar and thoracolumbar idiopathic scoliosis in adolescents and adults. Spine,6: 483-488, 1981.6483 1981 [PubMed]

Goldberg, M. S.; Mayo, N. E.; Poitras, B.; Scott, S.; and Hanley, J.: The Ste-Justine adolescent idiopathic scoliosis cohort study. Part I: Description of the study. Spine,19: 1551-1561, 1994.191551 1994 [PubMed]

Goldberg, M. S.; Mayo, N. E.; Poitras, B.; Scott, S.; and Hanley, J.: The Ste-Justine adolescent idiopathic scoliosis cohort study. Part II: Perception of health, self and body image, and participation in physical activities. Spine,19: 1562-1572, 1994.191562 1994 [PubMed]

Gorup, J.; Merola, A.; Zipnick, R.; Shin, T.; Halligan, S.; Caruso, S.; and Haher, T. H.: Scoliosis Research Society instrument: the initial experience. Orthop. Trans.,19: 640-641, 1995-1996.19640 1995-1996

Harvey, C. J., Jr.; Betz, R. R.; Clements, D. H.; Huss, G. K.; and Clancy, M.: Are there indications for partial rib resection in patients with adolescent idiopathic scoliosis treated with Cotrel-Dubousset instrumentation?. Spine,18: 1593-1598, 1993.181593 1993 [PubMed]

Jeng, C. L.; Sponseller, P. D.; and Tolo, V. T.: Outcome of Wisconsin instrumentation in idiopathic scoliosis. Minimum 5-year follow-up. Spine,18: 1584-1590, 1993.181584 1993 [PubMed]

King, H. A.: Selection of fusion levels for posterior instrumentation and fusion in idiopathic scoliosis. Orthop. Clin. North America,19: 247-255, 1988.19247 1988

King, H. A.; Moe, J. H.; Bradford, D. S.; and Winter, R. B.: The selection of fusion levels in thoracic idiopathic scoliosis. J. Bone and Joint Surg.,65-A: 1302-1313, Dec. 1983.65-A1302 1983

Lenke, L. G.; Bridwell, K. H.; Baldus, C.; and Blanke, K.: Analysis of pulmonary function and axis rotation in adolescent and young adult idiopathic scoliosis patients treated with Cotrel-Dubousset instrumentation. J. Spinal Disord.,5: 16-25, 1992.516 1992 [PubMed]

Lenke, L. G.; Bridwell, K. H.; Baldus, C.; and Blanke, K.: Preventing decompensation in King type II curves treated with Cotrel-Dubousset instrumentation. Strict guidelines for selective thoracic fusion. Spine,17 (Supplement 8): 274-S281, 1992.17 (Supplement 8)274 1992

Lenke, L. G.; Bridwell, K. H.; Baldus, C.; Blanke, K.; and Schoenecker, P. L.: Cotrel-Dubousset instrumentation for adolescent idiopathic scoliosis. J. Bone and Joint Surg.,74-A: 1056-1067, Aug. 1992.74-A1056 1992

Lenke, L. G.; Bridwell, K. H.; Baldus, C.; Blanke, K.; and Schoenecker, P. L.: Ability of Cotrel-Dubousset instrumentation to preserve distal lumbar motion segments in adolescent idiopathic scoliosis. J. Spinal Disord.,6: 339-350, 1993.6339 1993 [PubMed]

Lovallo, J. L.; Banta, J. V.; and Renshaw, T. S.: Adolescent idiopathic scoliosis treated by Harrington-rod distraction and fusion. J. Bone and Joint Surg.,68-A: 1326-1330, Dec. 1986.68-A1326 1986

Mayo, N. E.; Goldberg, M. S.; Poitras, B.; Scott, S.; and Hanley, J.: The Ste-Justine adolescent idiopathic scoliosis cohort. Part III: Back pain. Spine,19: 1573-1581, 1994.191573 1994 [PubMed]

Mielke, C. H.; Lonstein, J. E.; Denis, F.; Vandenbrink, K.; and Winter, R. B.: Surgical treatment of adolescent idiopathic scoliosis. A comparative analysis. J. Bone and Joint Surg.,71-A: 1170-1177, Sept. 1989.71-A1170 1989

Moore, M. R.; Baynham, G. C.; Brown, C. W.; Donaldson, D. H.; and Odom, J. A., Jr.: Analysis of factors related to truncal decompensation following Cotrel-Dubousset instrumentation. J. Spinal Disord.,4: 188-192, 1991.4188 1991 [PubMed]

Morrissy, R. T.; Goldsmith, G. S.; Hall, E. C.; Kehl, D.; and Cowie, G. H.: Measurement of the Cobb angle on radiographs of patients who have scoliosis. Evaluation of intrinsic error. J. Bone and Joint Surg.,72-A: 320-327, March 1990.72-A320 1990

Nash, C. L., Jr., and Moe, J. H.: A study of vertebral rotation. J. Bone and Joint Surg.,51-A: 223-229, March 1969.51-A223 1969

Poitras, B.; Mayo, N. E.; Goldberg, M. S.; Scott, S.; and Hanley, J.: The Ste-Justine adolescent idiopathic scoliosis cohort study. Part IV: Surgical correction and back pain. Spine,19: 1582-1588, 1994.191582 1994 [PubMed]

Richards, B. S.: Delayed infections following posterior spinal instrumentation for idiopathic scoliosis. Orthop. Trans.,19: 589, 1995-1996.19589 1995-1996

Richards, B. S., and Johnston, C. E., II: Cotrel-Dubousset instrumentation for adolescent idiopathic scoliosis. Orthopedics,10: 649-654, 1987.10649 1987 [PubMed]

Richards, B. S.; Birch, J. G.; Herring, J. A.; Johnston, C. E.; and Roach, J. W.: Frontal plane and sagittal plane balance following Cotrel-Dubousset instrumentation for idiopathic scoliosis. Spine,14: 733-737, 1989.14733 1989 [PubMed]

Richards, B. S.; Herring, J. A.; Johnston, C. E.; Birch, J. G.; and Roach, J. W.: Treatment of adolescent idiopathic scoliosis using Texas Scottish Rite Hospital instrumentation. Spine,19: 1598-1605, 1994.191598 1994 [PubMed]

Roye, D. P., Jr.; Farcy, J. P.; Rickert, J. B.; and Godfried, D.: Results of spinal instrumentation of adolescent idiopathic scoliosis by King type. Spine,17 (Supplement 8): 270-S273, 1992.17 (Supplement 8)270 1992

Schlenzka, D.; Poussa, M.; and Muschik, M.: Operative treatment of adolescent idiopathic thoracic scoliosis. Harrington-DTT versus Cotrel-Dubousset instrumentation. Clin. Orthop.,297: 155-160, 1993.297155 1993 [PubMed]

Shufflebarger, H. L., and Clark, C.: Cotrel-Dubousset instrumentation in adolescent idiopathic scoliosis. Orthop. Trans.,11: 49-50, 1987.1149 1987

Shufflebarger, H. L., and Clark, C. E.: Cotrel-Dubousset instrumentation. Orthopedics,11: 1435-1440, 1988.111435 1988 [PubMed]

Shufflebarger, H. L., and Crawford, A. H.: Point/counterpoint. Is Cotrel-Dubousset instrumentation the treatment of choice for idiopathic scoliosis in the adolescent who has an operative thoracic curve?. Orthopedics,11: 1579-1588, 1988.111579 1988 [PubMed]

Thometz, J. G., and Emans, J. B.: A comparison between spinous process and sublaminar wiring combined with Harrington distraction instrumentation in the management of adolescent idiopathic scoliosis. J. Pediat. Orthop.,8: 129-132, 1988.8129 1988

Thompson, G. H.; Wilber, R. G.; Shaffer, J. W.; Scoles, P. V.; and Nash, C. L., Jr.: Segmental spinal instrumentation in idiopathic scoliosis. A preliminary report. Spine,10: 623-630, 1985.10623 1985 [PubMed]

Thompson, J. P.; Transfeldt, E. E.; Bradford, D. S.; Ogilvie, J. W.; and Boachie-Adjei, O.: Decompensation after Cotrel-Dubousset instrumentation of idiopathic scoliosis. Spine,15: 927-931, 1990.15927 1990 [PubMed]

Wasylenko, M.; Skinner, S. R.; Perry, J.; and Antonelli, D. J.: An analysis of posture and gait following spinal fusion with Harrington instrumentation. Spine,8: 840-845, 1983.8840 1983 [PubMed]

West, J. L.; Boachie-Adjei, O.; Bradford, D. S.; and Ogilvie, J. W.: Decompensation following CD instrumentation: a worrisome complication. Orthop. Trans.,13: 78-79, 1989.1378 1989

Wood, K. B.; Transfeldt, E. E.; Ogilvie, J. W.; Schendel, M. J.; and Bradford, D. S.: Rotational changes of the vertebral-pelvic axis following Cotrel-Dubousset instrumentation. Spine,16 (Supplement 8): 404-S408, 1991.16 (Supplement 8)404 1991

Topics

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-B: Preoperative radiograph made in the sagittal plane. The severe three-dimensional deformity made it difficult to visualize and measure the curve.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-C: Anteroposterior radiograph, made two years postoperatively, showing a 42-degree thoracic curve and a 15-degree lumbar curve.

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-E: Lateral radiograph, made two years postoperatively, showing a -68-degree sagittal alignment (68 degrees of lumbar lordosis).

View Large | Download Slide(.ppt)
Add to My JBJS

Fig. 1-F: Lateral radiograph, made five years and three months postoperatively, showing 70 degrees of lumbar lordosis. The correction has been maintained.

View Larger

TABLE I CORONAL PARAMETERS

*At an average of three years (range, two to five years)²⁸. †At an average of six years (range, five to ten years).

	Primary Cobb Angle³⁴(cm)	Apical Vertebral Translation (cm)	Vertebral Tilt of Most Caudad Level with Instrumentation (degrees)	Translation of Most Caudad Level with Instrumentation (cm)
Preop.	53 (40—138)	5 (1—15)	18 (0—46)	1.3 (0—5)
Follow-up
Preliminary*	28 (5—55)	2 (0—5)	7 (0—20)	0.9 (0—4)
Latest†	29 (5—57)	2 (0—6)	6 (0—22)	0.7 (0—4)

Add to My JBJS

TABLE I CORONAL PARAMETERS

*At an average of three years (range, two to five years)²⁸. †At an average of six years (range, five to ten years).

	Primary Cobb Angle³⁴(cm)	Apical Vertebral Translation (cm)	Vertebral Tilt of Most Caudad Level with Instrumentation (degrees)	Translation of Most Caudad Level with Instrumentation (cm)
Preop.	53 (40—138)	5 (1—15)	18 (0—46)	1.3 (0—5)
Follow-up
Preliminary*	28 (5—55)	2 (0—5)	7 (0—20)	0.9 (0—4)
Latest†	29 (5—57)	2 (0—6)	6 (0—22)	0.7 (0—4)

View Larger

TABLE II SAGITTAL PARAMETERS

*At an average of three years (range, two to five years). †At an average of six years (range, five to ten years).

	Sagittal Alignment (degrees)
	T5—T12	T10—T12	T12-Most Caudad Level with Instrumentation	L1—L5	T12-Sacrum
Preop.	+18 (-15 to +62)	+4 (-19 to +26)	-6 (-40 to +9)	-42 (-6 to -73)	-50 (0 to -87)
Follow-up
Preliminary*	+23 (+6 to +68)	+7 (-7 to +28)	-6 (-42 to +15)	-46 (-15 to -75)	-59 (-30 to -84)
Latest†	+26 (+3 to +65)	+6 (-4 to +20)	-5 (-40 to +5)	-49 (-16 to -75)	-60 (-20 to -85)

Add to My JBJS

TABLE II SAGITTAL PARAMETERS

*At an average of three years (range, two to five years). †At an average of six years (range, five to ten years).

	Sagittal Alignment (degrees)
	T5—T12	T10—T12	T12-Most Caudad Level with Instrumentation	L1—L5	T12-Sacrum
Preop.	+18 (-15 to +62)	+4 (-19 to +26)	-6 (-40 to +9)	-42 (-6 to -73)	-50 (0 to -87)
Follow-up
Preliminary*	+23 (+6 to +68)	+7 (-7 to +28)	-6 (-42 to +15)	-46 (-15 to -75)	-59 (-30 to -84)
Latest†	+26 (+3 to +65)	+6 (-4 to +20)	-5 (-40 to +5)	-49 (-16 to -75)	-60 (-20 to -85)