Shorter and sweeter: the 16-item version of the SRS questionnaire shows better structural validity than the 20-item version in young patients with spinal deformity.

PURPOSE: In patients with adult spinal deformity, it was previously shown that 16 of the non-management items of the SRS-instrument showed a better fit to the theoretical four-factor model (pain, function, self-image, mental health) than did all 20 items. Whether the same phenomenon is observed in data from younger (< 20y) patients, for whom the questionnaire was originally designed, is not currently known. METHODS: Confirmatory factor analysis was used to evaluate the factor structure of the 20 non-management items of the SRS-instrument completed by 3618 young patients with spinal deformity (75.5% female; mean age, 15.0 ± 2.0 years) and of its equivalence across language versions (2713 English-speaking, 270 Spanish, 264 German, 223 Italian, and 148 French). The root mean square error of approximation (RMSEA) and comparative fit index (CFI) indicated model fit. RESULTS: Compared with the 20-item version, the 16-item solution significantly increased the fit (p < 0.001) across all language versions, to achieve good model fit (CFI = 0.96, RMSEA = 0.06). For both 16-item and 20-item models, equivalence across languages was not reached, with some items showing weaker item-loading for some languages, in particular German and French. CONCLUSION: In patients with adolescent idiopathic scoliosis, the shorter 16-item version showed a better fit to the intended 4-factor structure of the SRS-instrument. The wording of some of the items, and/or their equivalence across language versions, may need to be addressed. Questionnaire completion can be a burden for patients; if a shorter, more structurally valid version is available, its use should be encouraged.

[Dorsolateral access and interbody spinal fusion in spondylodiscitis of the thoracolumbar spine (TLIF technique)]. / Dorsolateraler zugang und interkorporelle spondylodese bei spondylodiszitis der brust- und lendenwirbelsäule (TLIF-technik).

UNLABELLED: SURGICAL GOAL: Resolve infection and achieve primary stability of instrumentation and permanent fusion of the affected spinal segment by means of debridement of the focus of infection. Defect-filling using autologous/allograft bone or a spacer, as well as immobilization by means of dorsal instrumentation. INDICATION: Acute and chronic thoracolumbar spondylodiscitis. CONTRAINDICATIONS: Purely epidural abscesses requiring only decompression (fenestration). Defects whose size make a ventral approach necessary. SURGICAL TECHNIQUE: Classic dorsal approach to the thoracolumbar spine. Pedicle placed using screws depending on the size of the spinal defect for mono-, bi-, or multisegmental spinal fusion. Exposure performed at the level of the infected spinal disc or vertebral body on the more strongly affected side. Focus of infection removed. Depending on the degree of infection, defect filling is carried out using autologous bone or cancellous allograft, followed by rod assembly. POSTOPERATIVE MANAGEMENT: Back brace-free follow-up treatment, physiotherapy and back training. Antibiotic administration until inflammation values fall within the normal range, or for at least 14 days. RESULTS: Successful fusion of affected segments, including resolution of infection, is reported in over 90% of cases described in the literature. The revision rate among our mostly multimorbid patient group with an average age of 66 years was 16%. Of 39 of the 114 (34%) patients with preoperative neurological deficits, 26 (66%) demonstrated postoperative regression. Nine patients (23%) showed no improvement, whilst exacerbation of existing neurological deficits was seen in four patients (11%). Staphylococcus was the major pathogen in 34% of cases.

[Reproducibility of readings of ISO C 3D and CT lumbar pedicle screw scans]. / Reproduzierbarkeit der Befundung von lumbalen Pedikelschraubenpositionen mit ISO C 3D und CT.

PURPOSE: This study was conducted to evaluate the reproducibility of the reading of lumbar pedicle screw scans using a C-arm-based imaging system in comparison to computed tomography. The influence of the technique and the experience of the rater should be determined. MATERIALS AND METHODS: The lumbar spines of 23 patients were stabilized using 102 pedicle screws. The position of the screws was controlled intraoperatively using an Arcadis Orbic 3D scanner. All scans were evaluated independently by three raters. The position of the implants in reference to the pedicle walls was described. Additionally, another 100 lumbar pedicle screws in 16 patients were evaluated postoperatively with a multirow CT. Kappa according to Fleiss was calculated for the reproducibility of the rater statements. Each rater repeated the analysis of 24 screws to assess the intraobserver variance. RESULTS: The reports of the CT scans showed significantly less variation. The consent of all 3 raters was achieved in 79.4 vs. 65.1 % of cases. The Kappa values were 0.56 and 0.29, respectively. Poor results were obtained especially for the medial pedicle wall (consent 70.0 vs. 50.0 %). The influence of the experience of the rater was not able to be verified. CONCLUSION: The image quality of the ISO C 3D is worse than that of multirow CT scans for the evaluation of lumbar pedicle screws. This causes greater variance among the rater reports. We stopped using the ISO C 3D technique intraoperatively for the implantation of lumbar pedicle screws.

Evaluation of uridine metabolism in human and animal spermatozoa.

The objective of this study was to elucidate the role of uridine for spermatozoa, since this pyrimidine nucleoside was found in millimolar concentration in human seminal plasma. Here, the degradative activity of uridine-phosphorylase [EC 2.4.2.3] and the salvage activity of uridine kinase [EC 2.7.1.48] were detected in human spermatozoa. HPLC analysis depicted the uptake of exogeneous 14C-labelled adenine, but not of uridine and of hypoxanthine, into nucleotide pools of boar spermatozoa. On addition of uridine, the computer-assisted semen analysis (CASA) of human cells revealed a reduction of the percentage of motile spermatozoa in contrast to an elevation of some velocity parameters. It is concluded that exogeneous uridine could function as suppressor for early capacitation and as a substrate for phosphorolysis, if ribose is needed, rather than to satisfy a demand for intracellular pyrimidine nucleotides.

In vitro fixator rod loading after transforaminal compared to anterior lumbar interbody fusion.

BACKGROUND: Cages are commonly used to assist lumbar interbody fusion. They are implanted from various approaches. In many cases internal fixators are added to provide sufficient stability. However, how the rods of these fixators are loaded and whether the kind of approach affects these loads is still unknown. The aim of this in vitro study therefore was to determine the loads acting on fixator rods and cages after anterior compared to transforaminal lumbar interbody fusion. METHODS: Six intact human lumbar spine specimens (L1-5) were loaded in a spine tester with pure moments (+/-7.5 N m) in the frontal, sagittal and transverse plane. Loading was repeated, first, after the segments L2-3 and L4-5 were instrumented either with an anterior or a transforaminal lumbar interbody fusion cage "stand alone" and, second, after additional stabilisation with an internal fixator. The rods of the fixator and the four "corners" of the cages were instrumented with strain gauges. FINDINGS: The loads transmitted through the rods were highest in lateral bending. In this loading direction an axial distraction force of in median up to 140 N, an axial compression force of up to 100 N, and a resultant bending moment of up to 1.1 N m were measured in each rod. These loads tended to be lower for the anterior compared to the transforaminal approach. For comparison, the load applied was +/-7.5 N m. The axial strains recorded in the four "corners" of the cages considerably varied from one specimen to the other. Differences in cage strain between the two approaches could not be detected. INTERPRETATION: The loads acting on the rods of the fixator were small compared to the load that was applied. Thus, other structures such as the cages or the facet joints still play an important role in load transfer. The type of approach (anterior or transforaminal) had only little effect on the loading of the rods. This also applies to the local loading of the cages, which probably more depends on the fit between cage and endplates and on the local stiffness properties of the adjacent vertebral bodies.

[Comparison of conventional full spine radiographs and fluoroscopic scanning method in young patients with idiopathic scoliosis]. / Vergleich von konventioneller Wirbelsäulenganzaufnahme und fluoroskopischer Scan-Methode bei jungen Patienten mit idiopathischer Skoliose.

PURPOSE: Evaluation of low-dose full spine radiographs using fluoroscopic images for the assessment of the Cobb angle measurement in patients with scoliosis. MATERIAL AND METHODS: Twenty-one consecutive patients (aged 10 - 27 years, mean age 14 years) with a conventional full spine examination (film speed class 800) underwent a follow-up exam using digital pulsed fluoroscopy (Multi Diagnost 4, Philips Medical Systems, Eindhoven, The Netherlands). The mean follow-up was 9 months. During a synchronized scan with a C-arm speed of 4 cm/sec fluoroscopic images were stored with a pulsed frequency of 3 images per second. The single images were merged and reconstructed to one image with the software Easy Spine (Philips medical Systems, Eindhoven, The Netherlands). The corresponding dose-area product values (DAP) of both methods were compared. Three independent observers assessed Cobb angles and image quality for each technique. RESULTS: The mean DAP values for conventional imaging was 94.9 cGy x cm (2) and for fluoroscopy 7.8 cGy x cm (2), respectively. A significant dose reduction of 91.8 % (CI 91 % to 95 %) was calculated. The average absolute angle difference between the observers was found to be 2.7 degrees for conventional imaging and 2.4 degrees for the fluoroscopic method. Interobserver standard deviation of 2.9 degrees was lower than the 5.3 degrees for conventional images. Image quality was better in the conventional images. CONCLUSION: Using the scanning method, we could achieve a mean reduction of the radiation dose of 92 %, while the accuracy of the Cobb angle measurements was comparable for both techniques despite of reduced image quality of digital fluoroscopy.

[Measurement of gravity line position 15-25 years after Harrington-spondylodesis in adolescent idiopathic scoliosis]. / Untersuchungen zum Schwerpunktlot 15-25 Jahre nach Harrington-Distraktionsspondylodese bei Patienten mit idiopathischer Adoleszentenskoliose.

AIM: A prospective analysis was performed to evaluate the relation between sagittal spinal morphology, gravity line position and morphological parameters of the pelvis and lumbar spine. METHOD: 25 patients with a mean follow-up of 23 (15-37) years after thoracic Harrington distraction spondylodesis were included. Standing lateral full spine radiographs were performed while patients were standing on a force plate. Pelvic angles according to Duval-Beaupere were measured. RESULTS: Pelvic incidence varied from 30 degrees to 76 degrees (mean 52.1 degrees + 12.5 degrees ). Mean sacral slope was 36.4 degrees (+ 7.8 degrees ). The average thoracic kyphosis (23.6 degrees + 14.3 degrees ) and lumbar lordosis (36.4 degrees + 9.2 degrees ) were diminished. The gravity line position was on average 10.9 mm (+ 21.6mm) posterior to the center of the femoral heads. CONCLUSION: Our method quantifies the relationship between the gravity line position and pelvic parameters according to Duval-Beaupere. The homogenous study group of patients with AIS after Harrington spondylodesis is characterized by decreased lumbar and thoracic profile and posterior displacement of the gravity line position.

A rare case of Salmonella osteomyelitis in the humerus as a differential diagnosis to a malignant bone tumor.

Salmonella osteomyelitis without predisposing factors is seldom seen and thus difficult to diagnose. We report on a 14-year-old healthy boy with Salmonella osteomyelitis which occurred 2 years after trauma. Radical operative debridement is recommended. Intravenous ciprofloxacin has proved to be effective because of good tissue penetration and sensitivity towards Salmonella.

Comparative analysis of pedicle screw and hook instrumentation in posterior correction and fusion of idiopathic thoracic scoliosis.

Posterior correction and fusion with segmental hook instrumentation represent the gold standard in the surgical treatment of progressive idiopathic thoracic scoliosis. However, there is a debate over whether pedicle screws are safe in scoliosis surgery and whether their usage might enable a better curve correction and a shorter fusion length. The details of curve correction, fusion length and complication rate of 99 patients with idiopathic thoracic scoliosis treated with either hook or pedicle screw instrumentation were analyzed. Forty-nine patients had been operated with the Cotrel-Dubousset system using hooks exclusively ("hook group"). Fifty patients had been operated with either a combination of pedicle screws in the lumbar and lower thoracic and hooks in the upper thoracic spine or exclusive pedicle screw instrumentation using the Münster Posterior Double Rod System ("screw group"). The preoperative Cobb angle averaged 61.3 degrees (range 40 degrees-84 degrees ) in the hook group and 62.5 degrees (range 43 degrees-94 degrees ) in the screw group. Average primary curve correction was 51.7% in the hook group and 55.8% in the screw group ( P>0.05). However, at follow-up (2-12 years later) primary curve correction was significantly greater ( P=0.001) in the screw group (at 50.1%) compared to the hook group (at 41.1%). Secondary lumbar curve correction was significantly greater ( P=0.04) in the screw group (54.9%) compared to the hook group (46.9%). Correction of the apical vertebral rotation according to Perdriolle was minimal in both groups. Apical vertebral translation was corrected by 42.0% in the hook group and 55.6% in the screw group ( P=0.008). Correction of the tilt of the lowest instrumented vertebra averaged 48.1% in the hook group and 66.2% in the screw group ( P=0.0004). There were no differences concerning correction of the sagittal plane deformity between the two groups. Fusion length was, on average, 0.6 segments shorter in the screw group compared to the hook group ( P=0.03). With pedicle screws, the lowest instrumented vertebra was usually one below the lower end vertebra, whereas in the hook group it was between one and two vertebrae below the lower end vertebra. Both operative time and intraoperative blood loss were significantly higher in the hook group ( P<0.0001). One pedicle screw at T5 was exchanged due to the direct proximity to the aorta. There were no neurologic complications related to pedicle screw instrumentation. Pedicle screw instrumentation alone or in combination with proximal hook instrumentation offers a significantly better primary and secondary curve correction in idiopathic thoracic scoliosis and enables a significantly shorter fusion length.

[Technique and results of monosegmental transpedicular subtraction osteotomy in patients with ankylosing spondylitis and fixed kyphotic deformity of the spine]. / Technik und Ergebnisse der monosegmentalen transpedikulären Wirbelkörpersubtraktionsosteotomie bei Patienten mit Spondylitis ankylosans und fixierter kyphotischer Deformität.

AIM: The posterior extension osteotomy leads to a lengthening of the anterior column, which is associated with neurological complications and the risk of injuring retroperitoneal structures. Especially in high-grade syndesmophytosis the results are dissatisfactory. In this study we report on the results of an alternative procedure named the transpedicular subtraction osteotomy. METHOD: After resection of the posterior elements of the vertebra at the level of the osteotomy, a wedge of the vertebral body including the pedicles with posterior basis is resected followed by an instrumented closing wedge, which leads to relordosation. 12 patients were treated with this method and reexamined with a minimum follow-up of 2 years (2 - 6 years). The level of osteotomy ranged from T12 to L3. RESULTS: The mean segmental correction averaged 30.1 degrees (25 - 36 degrees ). The overall relordosation averaged 35.9 degrees and was related to additional correction in the adjacent segments. With this dissatisfactory a sufficient correction of spinal balance and visual axis was obtained. All patients were satisfied with the result of the operation and would undergo surgery again from a retrospective point of view. CONCLUSION: With the transpedicular subtraction osteotomy fixed kyphotic deformities of the spine in patients with ankylosing spondylitis can be corrected produce safely. The level of osteotomy is discussed and should depend upon the apex of kyphosis.

[Halm-Zielke instrumentation as primary stable improvement of the Zielke-VDS in idiopathic scoliosis. 1 to 4 year outcome of a prospective study of 29 consecutive patients]. / Halm-Zielke-Instrumentation als primärstabile Weiterentwicklung der Zielke-VDS bei idiopathischen Skoliosen. 1- bis 4-Jahres-Ergebnisse einer prospektiven Studie bei 29 konsekutiven Patienten.

Halm-Zielke Instrumentation (HZI) was developed to eliminate the disadvantage of ventral derotation spondylodesis (VDS)-Zielke in terms of lack of primary stability and in order to simplify sagittal plane control. Within a prospective clinical trial started in 1993, we have studied whether HZI fulfills these demands. HZI is an anterior double-rod system with a two screw per vertebral body fixation. The longitudinal components consist of a threaded VDS rod and a solid rod, which are attached to a hinge-conducted lid plate. Twenty-nine consecutive patients with idiopathic scoliosis and curves ranging from 36 degrees to 92 degrees were treated with HZI. The follow-up period ranged from 1 to 4 years. Correction of the frontal plane within the instrumented levels averaged 71.6% and 70.5% postoperatively and at follow-up, respectively. Derotation averaged 53.7% and mean correction of the tilt of the lowest instrumented vertebra was 69.5% at final follow-up. Thoracolumbar kyphosis was present in eight patients and was always completely corrected from +18.8 degrees to 3.3 degrees on average. One implant-related complication involved a screw breakage 18 months postoperatively without adverse effects. There was no case of pseudoarthrosis. All patients were mobilized without any additional external immobilization in terms of a brace or cast, and were allowed to go swimming for physiotherapeutical purposes immediately after wound healing. This study proves that HZI is a primary stable implant to perform VDS. Implant-related disadvantages typical of VDS are eliminated. Thereby, the period of rehabilitation is shortened by many months due to avoidance of cast and brace treatment.

Segmental pedicle screw instrumentation in idiopathic thoracolumbar and lumbar scoliosis.

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 degrees and 60 degrees 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 degrees. 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 degrees, with a short fusion length, comparable to anterior fusion techniques, and minimal loss of correction.

[Halm-Zielke instrumentation in idiopathic scoliosis. Results in 25 consecutive patients with a minimum follow-up of 2 years]. / Halm-Zielke-Instrumentation bei idiopathischen Skoliosen. Ergebnisse bei 25 konsekutiven Patienten mit einem Mindestnachbeobachtungszeitraum von 2 Jahren.

AIM OF THE STUDY: Halm-Zielke Instrumentation (HZI) was developed to eliminate the disadvantage of VDS-Zielke in terms of lack of primary stability and in order to simplify sagittal plane control. Since 1993 we study within a prospective clinical trial, whether HZI fulfills these demands. METHODS: HZI is an anterior double-rod system with a two screw per vertebral body fixation. The longitudinal components consist of a threaded VDS-rod and a solid rod, which are attached to a hinge-conducted lid plate. 25 consecutive patients with idiopathic scoliosis and curves ranging from 36 degrees to 92 degrees were treated with HZI. The follow-up period ranges from 2 to 4 years. RESULTS: Correction of the frontal plane within the instrumented levels averaged 71.4% and 70.4% postoperatively and at follow-up, respectively. Derotation averaged 51.7% and mean correction of the tilt of the lowest instrumented vertebra was 69.5% at final follow-up. Thoracolumbar kyphosis was present in 7 patients and always completely corrected. One implant related complication, a screw breakage 12 months postoperatively without adverse effects was noted. There was no case of pseudarthrosis. All patients were mobilized without any additional external immobilization in terms of a brace or cast and were allowed to go swimming for physio-therapeutical purposes immediately after wound healing. CONCLUSION: This study proves that HZI is a primary stable implant to perform the Ventral Derotation Spondylodesis. The VDS-typical implant related disadvantages are eliminated. With this the period of rehabilitation is shortened by many months due to avoidance of cast and brace treatment.

Anterior thoracoscopic surgery followed by posterior instrumentation and fusion in spinal deformity.

Many authors believe thoracoscopic surgery is associated with a lower level of morbidity compared to thoracotomy, for anterior release or growth arrest in spinal deformity. Others believe that anterior release achieved thoracoscopically is not as effective as that achieved with the open procedure. We evaluated the clinical results, radiological correction and morbidity following anterior thoracoscopic surgery followed by posterior instrumentation and fusion, to see whether there is any evidence for either of these beliefs. Twenty-nine patients undergoing thoracoscopic anterior release or growth arrest followed by posterior fusion and instrumentation were evaluated from a clinical and radiological viewpoint. The mean follow-up was 2 years (range 1-4 years). The average age was 16 years (range 5-26 years). The following diagnoses were present: idiopathic scoliosis (n = 17), neuromuscular scoliosis (n = 2), congenital scoliosis (n = 1), thoracic hyperkyphosis (n = 9). All patients were satisfied with cosmesis following surgery. Twenty scoliosis patients had a mean preoperative Cobb angle of 65.1 degrees (range 42 degrees-94 degrees) for the major curve, with an average flexibility of 34.5% (42.7 degrees). Post operative correction to 31.5 degrees (50.9%) and 34.4 degrees (47.1%) at maximal follow-up was noted. For nine patients with thoracic hyperkyphosis, the Cobb angle averaged 81 degrees (range 65 degrees-96 degrees), with hyperextension films showing an average correction to 65 degrees. Postoperative correction to an average of 58.6 degrees was maintained at 59.5 degrees at maximal follow-up. The average number of released levels was 5.1 (range 3-7) and the average duration of the thoracoscopic procedure was 188 min (range 120-280 min). There was a decrease in this length of time as the series progressed. No neurologic or vascular complications occurred. Postoperative complications included four recurrent pneumothoraces, one surgical emphysema, and one respiratory infection. Thoracoscopic anterior surgery appears a safe and effective technique for the treatment of paediatric and adolescent spinal deformity. A randomised controlled trial, comparing open with thoracoscopic methods, is required.

[2- to 4-year outcome of dorsal double rod instrumentation spondylodesis in idiopathic scoliosis]. / 2- bis 4-Jahres-Ergebnisse dorsaler Doppelstabinstrumentationsspodylodesen bei idiopathischer Skoliose.

INTRODUCTION: In order to evaluate the results of posterior correction and fusion using the Münster Posterior Doublerod-System (MPDS) 48 patients with idiopathic scoliosis were studied prospectively. METHODS: All patients underwent clinical examination and radiological analysis of the frontal and sagittal plane preoperatively, postoperatively and at follow-up (2-4 years). Pedicle screws were used at the lumbar and thoracolumbar spine exclusively. RESULTS: The preoperative average Cobb angle was 61.4 degrees with an average flexibility of 36.8% to 38.8 degrees. The average postoperative Cobb angle was 24.8 degrees (59.6%) with an average loss of correction of 2.6 degrees Cobb angle (3.6%). Due to the use of thoracolumbar and lumbar pedicle screws instrumented fusion could be stopped at the lower endvertebra in 71%. Patients in whom only pedicle screws had been used improved correction of frontal plane could be shown compared to combined instrumentations with hooks and screws. CONCLUSION: The posterior instrumentation guarantees primary stability with good results of correction and allows brace free treatment postoperatively. The postoperative correction compared to the results at follow-up proves the stability of the instrumentation largely. The results of mainly pedicle screw based instrumentations verify that an improved correction can be achieved. In most cases fusion levels end at the lower end vertebra and therefore are shorter compared to instrumentation's based on hooks only.

Brown-Sequard syndrome after management of vertebral hemangioma with intralesional alcohol. A case report.

STUDY DESIGN: This report describes Brown-Sequard syndrome after intralesional injection of absolute alcohol into vertebral hemangioma. OBJECTIVE: To discuss whether the described technique is safe in the management of vertebral hemangiomas. SUMMARY OF BACKGROUND DATA: The management of vertebral hemangiomas remains controversial. There have been reports of successful management using intralesional absolute alcohol. METHODS: The clinical and radiologic features of the reported complication are detailed. RESULTS: Intralesional injection of absolute alcohol caused Brown-Sequard syndrome. CONCLUSION: This case shows that intralesional alcohol injection cannot be considered a safe technique for management of vertebral hemangiomas with spinal cord compression.

[Thoracoscopic interventions in deformities of the thoracic spine]. / Thorakoskopische Eingriffe bei Deformitäten der Brustwirbelsäule.

AIM OF THE STUDY: We prospectively studied 9 patients with deformities of the thoracic spine who underwent thoracoscopic surgery to critically evaluate the benefits and limitations of thoracoscopy. METHODS: Seven patients with deformities of the thoracic spine (5 scoliosis, 2 kyphosis) underwent a thoracoscopic release and posterior correction and fusion in a single stage. In one case of a crankshaft-phenomenon a thoracoscopic epiphyseodesis und in another case of a posttraumatic kyphosis a thoracoscopic instrumentation and fusion were performed. The average age was 21 years, the follow-up was 18 months with a minimum of 12 months. The perioperative data including complications were collected and a radiographic analysis concerning curve correction was carried out. RESULTS: The scoliotic curves measured preoperatively 84 degrees on average with a Cobb angle of 62 degrees on the traction films and were corrected by 57% to averagely 36 degrees at follow-up. In the two cases of Scheuermann kyphosis a preoperative kyphosis of 94 degrees respectively 82 degrees was corrected to 52 degrees respectively 58 degrees. Between 4 and 5 discs were excised with an average operative time of 160 min and a blood loss of 380 ml. A conversion to open thoracotomy was not necessary in any case. There were no intraoperative neurovascular complications. CONCLUSIONS: Thoracoscopic procedures in deformities of the thoracic spine are technically demanding; however, it is a minimally invasive procedure with a reduced approach-related morbidity compared to open thoracotomy. The indications for a thoracoscopic release are rigid kyphosis and scoliosis with rigid curves between 80 and 90 degrees Cobb angle in which an anterior correction and instrumentation alone is not considered.

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.

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 degrees to 77 degrees. 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 degrees to +1.7 degrees 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.