Henry Halm

Analysis of vertebral morphology in idiopathic scoliosis with use of magnetic resonance imaging and multiplanar reconstruction.

Background: Several studies have provided data on the vertebral morphology of normal spines, but there is a paucity of data on the vertebral morphology in patients with idiopathic scoliosis.Methods: The morphology of the pedicles and bodies of 307 vertebrae as well as the distance between the pedicles and the dural sac (the epidural space) in twenty-six patients with right-sided thoracic idiopathic scoliosis were analyzed with use of magnetic resonance imaging and multiplanar reconstruction.Results: A distinct vertebral asymmetry was found at the apical region of the thoracic curves, with significantly thinner pedicles on the concave side than on the convex side (p < 0.05). The degree of intravertebral deformity diminished farther away from the apex, with vertebral symmetry restored at the neutral level. In the thoracic spine, the transverse endosteal width of the apical pedicles measured between 2.3 mm and 3.2 mm on the concave side and between 3.9 mm and 4.4 mm on the convex side (p < 0.05). In the lumbar spine, the pedicle width measured between 4.6 mm at the cephalad part of the curve and 7.9 mm at the caudad part of the curve. The chord length and the pedicle length gradually increased from 34 mm and 18 mm, respectively, at the fourth thoracic vertebra to 51 mm and 25 mm, respectively, at the third lumbar vertebra. The transverse pedicle angle measured 15° in the cephalad aspect of the thoracic spine, decreased to 7° at the twelfth thoracic vertebra, and increased again to 16° at the fourth lumbar vertebra. The width of the epidural space was <1 mm at the thoracic apical vertebral levels and averaged 1 mm at the lumbar apical vertebral levels on the concave side, whereas it was between 3 mm and 5 mm on the convex side (p < 0.05).Conclusion: Idiopathic scoliosis is associated with distinctive intravertebral deformity, with smaller pedicles on the concave side and a shift of the dural sac toward the concavity.Clinical Relevance: Care must be exercised during pedicle-screw instrumentation, especially in the apical region of the concavity of thoracic curves, because of the small pedicle width and the limited epidural safe zone in this area. Surgeons should be aware of these altered conditions when considering pedicle-screw instrumentation for patients with thoracic scoliosis.

Segmental pedicle screw instrumentation in idiopathic thoracolumbar and lumbar scoliosis.

Abstract The role of posterior correction and fusion in thoracolumbar and lumbar scoliosis as well as pedicle screw instrumentation in scoliosis surgery are matters of debate. Our hypothesis was that in lumbar and thoracolumbar scoliosis, segmental pedicle screw instrumentation is safe and enables a good frontal and sagittal plane correction with a fusion length comparable to anterior instrumentation. In a prospective clinical trial, 12 consecutive patients with idiopathic thoracolumbar or lumbar scolioses of between 40° and 60° Cobb angle underwent segmental pedicle screw instrumentation. Minimum follow-up was 4 years (range 48– 60 months). Fusion length was defined according to the rules for Zielke instrumentation, normally ranging between the end vertebrae of the major curve. Radiometric analysis included coronal and sagittal plane correction. Additionally, the accuracy of pedicle screw placement was measured by use of postoperative computed tomographic scans. Major curve correction averaged 64.6%, with a loss of correction of 3°. The tilt angle was corrected by 67.0%, the compensatory thoracic curve corrected spontaneously according to the flexibility on the preoperative bending films, and led to a satisfactory frontal balance in all cases. Average fusion length was the same as that of the major curve. Pathological thoracolumbar kyphosis was completely corrected in all but one case. One patient required surgical revision with extension of the fusion to the midthoracic spine due to a painful junctional kyphosis. Eighty-five of 104 screws were graded “within the pedicle”, 10 screws had penetrated laterally, 5 screws bilaterally and 4 screws medially. No neurological complications were noted. In conclusion, despite the limited number of patients, this study shows that segmental pedicle screw instrumentation is a safe and effective procedure in the surgical correction of both frontal and sagittal plane deformity in thoracolumbar and lumbar scoliosis of less than 60°, with a short fusion length, comparable to anterior fusion techniques, and minimal loss of correction.

Osteoid osteoma and osteoblastoma of the spine: experiences with 22 patients.

Osteoblastomas and osteoid osteomas of the spine are relatively rare bone-forming tumors. Between 1980 and 1999, nine patients with osteoid osteoma and 13 patients with osteoblastoma had surgery for their tumors. Four tumors were in the cervical spine, six tumors were in thoracic spine, 10 tumors were in the lumbar spine, and two tumors were in the sacrum. The average duration between onset of pain and surgery was 16.6 months in 12 patients treated in the 1980s and 8.6 months in 10 patients treated in the 1990s. Seventeen patients had scoliosis. In nine of 10 patients with magnetic resonance imaging scans, high signal intensity areas in the muscles and bone around the lesion were seen. Two of nine patients with osteoid osteoma and nine of 13 patients with osteoblastoma had neurologic disorders before treatment. All patients had open resection of the lesions. Two patients with osteoid osteoma had relapse because of incomplete resection, necessitating a second excision. In 16 of 17 patients with preoperative spinal deformity, the deformity improved during followup. With development of modern imaging techniques, exact surgical planning may become possible; however, in some cases, intraoperative complete resection of the lesion still is difficult.

Clinical and Radiologic 2-4-Year Results of Transforaminal Lumbar Interbody Fusion in Degenerative and Isthmic Spondylolisthesis Grades 1 and 2

Study Design. Prospective clinical study. Objective. To evaluate the clinical and radiographic result of the transforaminal lumbar interbody fusion (TLIF) as an alternative new technique in degenerative and isthmic lower grade spondylolisthesis. Summary of Background Data. TLIF is a new alternative surgical technique used for spinal fusion avoiding the ventral approach and can theoretically prevent typical complications, such as those seen in anterior and posterior lumbar interbody fusion. Materials and Methods. There were 19 degenerative, 19 isthmic, and 1 dysplastic spondylolistheses operated on with TLIF. The clinical follow-up used the Oswestry Disability Index, the radiologic follow-up radiograph, analyzing segmental lordosis, intervertebral space, reduction, and fusion rate. The minimum follow-up was 24 months, mean clinical follow-up was 50 months, and radiologic follow-up was 35 months. Results. The medium of the Oswestry Disability Index in all patients decreased from 23.5 to 13.5 points, in isthmic spondylolistheses from 20.5 to 10.95 after 2 years. The radiographic fusion rate was 94.8%. The sagittal translation was reduced from 23% to 15%. There were 3 (7.6%) serious postoperative complications observed, which required operative revision. Conclusions. TLIF is a safe and effective method to treat low-grade spondylolisthesis, which can theoretically prevent typical complications of anterior and posterior lumbar interbody fusion. The results of isthmic spondylolistheses were significantly better compared to degenerative spondylolistheses.

Giant cell tumor of the spine.

Six patients with giant cell tumor of the spine had surgery between 1981 and 1995. Three lesions were located in the scrum, two lesions were in the thoracic spine, and one lesion was in the lumbar spine. Preoperatively, all patients had local pain and neurologic symptoms. Two patients had cement implanted after curettage or intralesional excision of the sacral tumor; one patient had a local relapse. After the second curettage and cement implantation, the tumor was controlled. One patient with a sacral lesion had marginal excision and spondylodesis; no relapse developed. Two patients with thoracic lesions had planned marginal excision and spondylodesis; the margins finally became intralesional, but no relapse developed. One patient with a lumbar lesion had incomplete removal of the tumor and received postoperative irradiation. At the final followup (median, 69 months), five of six patients were disease-free and one patient died of disease progression. Two of the five surviving patients had pain after standing or neurologic problems. Although some contamination occurred, planning a marginal excision of the lesion seems beneficial for vertebral lesions above the sacrum. Total sacrectomy of a sacral lesion seems to be too invasive when cement implantation can control the lesion.

Dual-rod correction and instrumentation of idiopathic scoliosis with the Halm-Zielke instrumentation

Study Design. A prospective clinical and radiographic evaluation of 45 consecutive patients with idiopathic adolescent and adult scoliosis treated with anterior dual-rod Halm-Zielke instrumentation. Objectives. Clinical and radiographic evaluation with a minimum follow-up of 2 years. Summary of Background Data. Halm-Zielke instrumentation was developed to eliminate the disadvantages of Zielke instrumentation in terms of lack of primary stability and a kyphogenic effect. Methods. All patients underwent an identical anterior surgical technique with the Halm-Zielke instrumentation of the primary curve. The system is composed of a lid-plate, which is fixed to the lateral aspect of the vertebral body with two screws: a sunk screw anteriorly and a ventral derotation spondylodesis (VDS) screw posteriorly. The lid-plate design provides the lowest possible implant profile. The longitudinal components consist of a threaded rod and a solid, fluted rod. Correction is performed with both the threaded and the solid rod. The solid rod allows derotation and correction of the sagittal plane and provides primary stability. Results. Preoperative curves ranged from 35° to 92° Cobb angle. Final correction of the frontal plane averaged 67% within the instrumented levels and 59% for the total primary curve. The apical vertebral rotation of the primary curve was corrected by 52% on average without loss of correction during follow-up. Thoracolumbar kyphosis was present in 11 patients and corrected in all cases from an average of 20° to 2° after surgery and to 8° at follow-up. We observed two cases of implant failure with one resulting in a pseudarthrosis. Conclusion. Halm-Zielke instrumentation proved to be a major improvement of the original VDS-Zielke. It eliminates the kyphogenic effect and provides primary stability.

Results of surgical correction of kyphotic deformities of the spine in ankylosing spondylitis on the basis of the modified arthritis impact measurement scales.

Study Design This is a retrospective study of patient outcome in ankylosing spondylitis patients with fixed kyphotic deformities of the spine who underwent reconstructive surgery. Objectives To measure the multidimensional effects of reconstructive spinal osteotomy in this patient group with a questionnaire-based instrument. Summary of Background Data Between 1979 and 1988, 175 ankylosing spondylitis patients underwent operative treatment for fixed flexion deformities of the spine. One hundred forty-eight of these patients answered the questionnaire correctly and were included in the study. The others either died or were lost to follow-up. Methods The modified Arthritis Impact Measurement Scales with eight scales and 60 items plus six additional summative questions were administered at a mean follow-up period of 4.8 years (range, 2–10 years). The modified Arthritis Impact Measurement Scale measures eight scales-mobility, physical, household, daily, social activity, pain, anxiety, and depression. The Wilcoxon and chi-square test were used for analysis. Results Forty-seven of 60 items showed significant improvement of activity levels or status. Only two items showed a significant impairment of function. Of the patients, 88.4% were very satisfied with the result of the operation; 60.9% were able to return to work. Age, sex, and type of surgical technique did not influence the results. Conclusions The modified Arthritis Impact Measurement Scales approach shows excellent overall improvement of health status after surgery, proving the worth of reconstructive surgery in ankylosing spondylitis patients with fixed kyphotic deformities of the spine.

Validity and Reliability of an Adapted German Version of Scoliosis Research Society-22 Questionnaire

Study Design. Study to determine the internal consistency and validity of adapted German version of Scoliosis Research Society-22 (SRS-22) questionnaire. Objective. To evaluate the validity and reliability of adapted German version of SRS-22 questionnaire. Summary of Background Data. The SRS-22 questionnaire was developed to assess the health-related quality of life for English-speaking patients with idiopathic scoliosis. For scientific purpose and standardized comparison of outcome studies for the treatment of idiopathic scoliosis its adaptation into German is necessary to respect cultural and lingual differences. Methods. Translation/retranslation of the English version of the SRS-22 was conducted, and all steps for cross-cultural adaptation process were performed. Thus, SRS-22 questionnaire and previously validated Roland-Morris score were mailed to 222 patients who had been treated surgically or conservatively for idiopathic scoliosis. Seventy-eight patients (35%) responded to the first set of questionnaires and 54 of the first time responder returned their second survey. The median age of all patients who joined the study was 19 years. Measures of reliability namely, selectivity, internal consistency, and reproducibility were determined by Cronbach’s &agr; statistics and intraclass correlation coefficient, respectively. Concurrent validity was measured by comparing with an already validated questionnaire (Roland-Morris score). Measurement was made using the Spearman correlation coefficient. Results. The study demonstrated satisfactory internal consistency with high Cronbach’s &agr; values for 4 of the corresponding domains (pain, 0.75; self-image, 0.84; mental health, 0.88; and satisfaction, 0.61). However, the Cronbach’s &agr; value for function/activity domain (0.67) was considerably lower than the original English questionnaire. For the same domains intraclass correlation coefficient demonstrating satisfactory test/retest reproducibility. Conclusion. The adapted German version of the SRS-22 questionnaire can be used to assess the outcome of treatment for German-speaking patients with idiopathic scoliosis.

Spontaneous correction and derotation of secondary curves after selective anterior fusion of idiopathic scoliosis.

Study Design. Clinical, rasterstereographic, and radiographic evaluation of spontaneous vertebral derotation of secondary curves in idiopathic scoliosis following selective anterior correction and fusion of the primary curve. Objective. To quantify spontaneous vertebral derotation in secondary curves after selective anterior correction with attention to cosmetic outcome. Summary of Background Data. While the derotational effect of anterior instrumentation techniques on the instrumented curve is well understood, there is a paucity on data of the rotational behavior of the noninstrumented secondary curves. Methods. A total of 43 patients with idiopathic scoliosis (16 with thoracic curves in group 1 and 27 with thoracolumbar/lumbar curves in group 2) underwent selective anterior instrumentation. Vertebral rotation was analyzed before surgery and, on average, 20 months after surgery using digital radiometric rotation analysis, back shape analysis with rasterstereography, and scoliometer measurement. Results. In Group 1, there was a significant spontaneous vertebral derotation of the secondary lumbar curves by 14.2% (range from 12.7° to 10.9°) in the digital radiometric rotation analysis, surface derotation amounted to 49% (range from 9.6° to 4.9°) in the rasterstereography, and to 70% in the clinical scoliometer measurement (range from 8.0° to 2.4°). In group 2, there was an increase of rotation of the noninstrumented secondary thoracic curves by 30% (range from 5.0° to 6.5°) in digital radiometry, by 32.9% in the rasterstereography (range from 8.5° to 11.3°), and a 28.3% increase in scoliometer measurement (range from 6.0° to 7.7°). Conclusion. Selective anterior instrumentation and fusion of primary thoracic curves results in satisfactory spontaneous vertebral and high surface derotation of the secondary lumbar curves. However, in primary thoracolumbar or lumbar curves, an increase of both vertebral and surface rotation of the secondary thoracic curve was noted. This increase can impair cosmetic outcome.

Halm-Zielke instrumentation for primary stable anterior scoliosis surgery: operative technique and 2-year results in ten consecutive adolescent idiopathic scoliosis patients within a prospective clinical trial.

Abstract Halm-Zielke instrumentation (HZI) was developed to eliminate the disadvantages of Zielke instrumentation (VDS) in terms of lack of primary stability and a kyphogenic effect. HZI is an anterior double-rod system. The system is composed of a lid-plate, which is fixed at the lateral aspect of the vertebral body with two screws, a sunk screw anteriorly and a VDS screw posteriorly. The lid-plate design provides the lowest possible implant profile. The longitudinal components consist of a threaded VDS rod and a solid, fluted rod. Correction is performed with the threaded rod and the solid rod. The solid rod allows internal derotation and relordosation, eliminates the Zielke three-point lever system and augments the system. The fluted design of the rod provides rotatory stability. This is a report of the first ten consecutive adolescent idiopathic scoliosis patients in a prospective clinical trial using HZI with a minimum follow-up of 2 years. Curves ranged from 36° to 77°. Correction of the frontal plane averaged 77.5% and 72.2% postoperatively and at follow-up, respectively. Thoracolumbar kyphosis was present in three patients and corrected in all from an average of + 18° to +1.7° at follow-up. Implant-related complications were not observed. All patients were treated without any additional external immobilization. In our opinion, HZI is a major improvement on the original Zielke VDS. It eliminates the kyphogenic effect and provides primary stability.