[Surgical treatment of infantile and juvenile scoliosis--a retrospective analysis of 21 patients]. / Die operative Behandlung infantiler und juveniler Skoliosen - eine retrospektive Analyse von 21 Patienten.

PROBLEM: We carried out a retrospective analysis of 21 patients with infantile or juvenile scoliosis (9 boys, 12 girls) who underwent surgical treatment between 1985 and 1997. 13 patients underwent primary dorsal instrumentation without fusion (growing-rod group). In contrast, 8 patients received already in this young age an instrumented spondylodesis (fusion-group). PATIENTS AND METHODS: The initial examination was performed at an age of 6 years (median; range 29 years), and first surgery was performed at an age of 8 years (median, range 310 years). The patients have been followed-up clinically and radiologically at an age of 16 years (median; range 1021 years). RESULTS: The preoperative measurement showed no significant differences between both groups (thoracic Cobb angle 77 degrees versus 66 degrees [median], lumbar Cobb angle 40 degrees versus 51 degrees [median]). At follow-up we measured significantly better results in the fusion-group than in the growing-rod group (thoracic Cobb angle 24 degrees versus 60 degrees [median; p < 0.01]), lumbar Cobb angle 21 degrees versus 34 degrees [median, p < 0.05]). The fusion-group also showed significantly better results with respect to the parameters (median values given): duration of hospital stay (14 versus 150 days), number of operations per patient (2 versus 3) and number of complications (0 versus 26). CONCLUSION: Based on the results of this small patient group we no longer see an indication to treat infantile and juvenile scoliosis by dorsal instrumentation without fusion. In contrast, we find the principle of short instrumented anterior fusion to be more promising.

Beta-tricalcium phosphate as a bone substitute for dorsal spinal fusion in adolescent idiopathic scoliosis: preliminary results of a prospective clinical study.

The aim of this study is to evaluate the ability of beta-tricalcium phosphate (TCP) in granular form to achieve dorsal spondylodesis in adolescent idiopathic scoliosis (AIS). Twenty-eight patients underwent surgical correction and were followed up for 13+/-8 (range 6-33) months. Posterolateral grafting was performed, using either autograft bone mixed with allograft bone (n=19; "bone group") or autograft bone mixed with 25 g TCP (n=9; "TCP group"). Patients were followed by clinical examination, X-rays and computed tomographic (CT) scans to measure bone mineral density. Fusion involved 12+/-1 (range 10-14) vertebrae. The segments were fused after 6+/-1 months in both groups according to the radiographs. No pseudarthrosis was observed. Bone mineral density was 430+/-111 (range 273-629) mg/cm3 in the TCP group versus 337+/-134 (range 130-669) mg/cm3 in the bone group. Resorption of TCP was complete on the radiographs after 8+/-2 (range 6-10) months. Based upon the results of this small preliminary study, the use of TCP appears to be a valuable alternative to allografts for application in the spine, even when large amounts of bone are needed.

[Chronic osteomyelitis of the ilium after autologous bone harvesting in Albers-Schonberg osteopetrosis. A case report]. / Chronische Osteomyelitis des Os ileum nach autologer Knochenentnahme bei Osteopetrosis Albers-Schonberg. Eine Kasuistik.

We report the treatment of chronic osteomyelitis of the iliac wing after autologous bone harvesting in a 17-year old boy with osteopetrosis. A partial resection of the iliac wing was performed followed by systemic antibiotic treatment. The wound healing was without complications. We consider autologous bone harvesting in patients with osteopetrosis to be a critical procedure due to the higher risk of infection.

[Treatment of knee dislocation after callus distraction of the femur--a case report]. / Die Behandlung einer Knieluxation nach Kallusdistraktion des Oberschenkels--ein Fallbericht.

We report on the therapy of a complete ventrocranial luxation of the knee joint with leg shortening of 20 cm, which had appeared after diaphyseal distraction osteogenesis in the left thigh at the age of 7 years. The patient presented herself in our clinic at the age of 14 years. After application of an llizarov external fixator,first the luxation was gradually repositioned and afterwards arthrodesis of the knee joint was carried out. After consolidation of the arthrodesis, we removed the external fixator and carried out a unilateral, diaphyseal callus distraction in the left femur. The consolidation of the distraction callus of 12 cm was completed after 9 months and the fixator was removed. At the age of 18 years, 2 years after the treatment was completed, the patient was free of pain and able to walk safely. The remaining shortening of the left leg amounted to 2.5 cm and was balanced in the shoe proportionately.

Experimental anterior spine fusion using bovine bone morphogenetic protein: a study in rabbits.

We developed an experimental model to study the merit of bovine bone morphogenic protein (bBMP) injection into the intervertebral disc to induce anterior interbody fusion. A total of 24 rabbits, divided into three groups of 8 animals each, were used. One hundred and fifty microg of partially purified bBMP was employed in the first group and 10 microg bBMP in the second group. In the control group, a sham operation was performed. The animals were followed radiographically at weekly intervals and animals were killed 3, 6, and 12 weeks postoperatively. After sacrifice, a mechanical and histologic evaluation of fusion was performed. Results of radiographic and histologic evaluation showed bone formation, which had resulted in the bridging of adjacent endplates, in the 150-microg group. In the 10-microg group, new bone formation was less extensive. In the control group, intradiscal bone formation was seen in only 1 animal. Range of motion measurements on flexion/extension films showed significantly decreased motion in segments that were fused with 150-microg of BMP. This study demonstrated the utility of an experimental model which allowed investigation of how anterior spine fusion may be further studied. Intradiscal injection of BMP could ultimately play a role in the development of minimally invasive techniques for anterior spinal fusion.

[Surgical therapy of hemivertebrae scoliosis and kyphosis--a retrospective analysis of 53 cases]. / Operative Therapie von Halbwirbelskoliosen und -kyphosen--Eine retrospektive Analyse von 53 Fällen.

AIM OF THE STUDY: We performed a retrospective analysis of the results of operative treatment of 53 patients with congenital scoliosis (n = 47) or kyphosis (n = 6) due to hemivertebrae. PATIENTS AND METHODS: The mean age of the patients (31 girls and 22 boys) at the time of the initial examination was 6 +/- 4 years. Surgical treatment was carried out on average at the age of 9 +/- 5 years. Follow-up examinations were carried out up to a mean age of 16 +/- 6 years. RESULTS: The results of operative treatment depended on the localization of the hemivertebrae and the surgical technique. Progression of scoliosis due to a thoracic hemivertebra was halted, but the scoliosis could not be corrected (Cobb angle at initial examination 37 +/- 17 degrees at follow-up 34 +/- 23 degrees). Scoliosis due to lumbar hemivertebrae was reduced by surgery (Cobb angle at initial examination 36 +/- 14 degrees, at follow-up 21 +/- 15 degrees). Surgery without instrumentation led to worse results than did surgery with instrumentation with thoracic as well as lumbar scoliosis. Combined dorsoventral procedures with resection of the hemivertebra seemed to be superior to spondylodesis without resection of the hemivertebra. Surgical correction of kyphosis associated with dorsal hemivertebrae was performed by means of dorsal or dorsoventral spondylodesis with hemivertebra resection (preoperative kyphosis 70 +/- 34 degrees, at follow-up 44 +/- 25 degrees). CONCLUSION: Spondylodesis without instrumentation is associated with an unsure prognosis with respect to effects on the progression of the scoliosis, even if it is performed on very young patients. In contrast, spondylodesis with instrumentation can achieve better and longer-lasting corrections of scoliosis even with larger initial curvatures. Scoliosis due to lumbar hemivertebrae is more amenable to surgical correction than thoracic scoliosis due to hemivertebrae.

The influence of obesity on perioperative morbidity and mortality in revision total hip arthroplasty.

The significance of obesity as a risk factor for postoperative complications was determined in a consecutive series of 229 cases of revision total hip replacement. The body mass index (BMI) was used as an objective measure to classify the patients. The group-wise analysis of data included all medical and procedure-related complications, the number of fatal cases, operative time, requirement for analgesics, the number of transfusions and perioperative haemoglobin levels. The results of our study demonstrate a clear association between obesity and operative time, whereas no statistically significant relationships were observed between obesity and the other parameters. We conclude that obesity does not have any significant influence on perioperative morbidity and mortality but is clearly related to operation time and, therefore, to higher costs per operation.

Joint cartilage repair with transplantation of embryonic chondrocytes embedded in collagen-fibrin matrices.

OBJECTIVE: The objective of this study was to assess the feasibility of transplanting embryonic chondrogenic cells within a collagen-fibrin substrate for the reconstitution of full-thickness cartilage defects in chicken knee joints. METHODS: Full-thickness cartilage defects were created mechanically on the weight-bearing surface of the tibial condyle in 45 adult chickens and subsequently filled with chondrocytes embedded in a chondrocyte-collagen-fibrin gel. The transplants were compared to untreated defects and collagen-fibrin transplants without cells. The results were analyzed using histochemical and morphometrical methods after 3, 12 and 24 weeks. A semiquantitative histological grading system was applied to evaluate the transplant integration and the newly formed cartilage architecture. RESULTS: Chondrocyte-gel grafts developed to hyaline-like cartilage without any granulation tissue in the interface after 3 weeks. After 12 weeks the defects in the experimental group were filled completely with hyaline cartilage. The defects in the control groups in all cases healed with fibrous repair tissue. CONCLUSION: Fibrin-collagen gel allowed stable graft fixation and provided an adequate microenvironment for embryonic chondrocytes to generate hyaline-like neocartilage in a full-thickness cartilage defect.

Dorsal instrumentation for idiopathic adolescent thoracic scoliosis: rod rotation versus translation.

The radiographic and clinical outcomes and complications among two groups of adolescent patients treated for idiopathic thoracic scoliosis with dorsal instrumentation using a unified implantation system (Universal Spinal System) were compared retrospectively. A total of 69 patients were included in the study. In 30 patients an intraoperative correction of the scoliosis was performed by translation and segmental correction (translation group, Helsinki). In 39 patients the correction was achieved according to the Cotrel-Dubousset rod rotation maneuver (rod rotation group, Berlin). The goal of the present study is to investigate whether one of the operative procedures leads to a better correction of idiopathic adolescent thoracic scoliosis than the other. The mean follow-up interval was 30 months, with a minimum of 12 months. There were no significant preoperative differences in age (15+/-2 years in both groups), gender, or type of scoliosis (King types 2, 3, and 4). The preoperative radiographic measurements showed no significant differences between the two groups. In both patient groups, the thoracic primary curve, the lumbar secondary curve and the thoracic apical rotation were improved by the operation. Lumbar apical rotation and the sagittal profile were unchanged in both groups. The thoracic primary curve was corrected from 50 degrees +/-6 degrees to 24 degrees +/-7 degrees in the translation group and from 54 degrees +/-11 degrees to 220 degrees +/-11 degrees in the rod rotation group. The extent of the correction of the thoracic curve was significantly greater in the rod rotation group than in the translation group (59% vs. 52% correction). In contrast, the translation procedure seems to have a more beneficial effect on spinal balance than rod rotation. Neurological complications did not occur. In both patient groups an increase in the non-instrumented lumbar curve was noted, in two cases each. In three patients from the rod rotation group the instrumentation had to be removed due to a late infection with negative microbiological results.

Surgical management of severe spondylolisthesis in children and adolescents. Anterior fusion in situ versus anterior spondylodesis with posterior transpedicular instrumentation and reduction.

STUDY DESIGN: A clinical and radiologic retrospective follow-up examination of patients treated surgically for severe juvenile spondylolisthesis. OBJECTIVE: To compare two different surgical techniques in the management of severe (degree of slip > 30%) juvenile spondylolisthesis (anterior spondylodesis in situ versus combined anterior spondylodesis and posterior transpedicular instrumentation including reduction of the slipping vertebra) to determine if the advantages of the repositioning of the slipping vertebra and a decreased number of pseudarthroses because of the transpedicular instrumentation lead to clinical improvement despite showing better alignment radiologically. METHODS: This study included 59 children and adolescents with severe spondylolisthesis of L5 who were treated surgically at the authors' orthopedic department between 1980 and 1992. Twenty-nine children received anterior spondylodesis (AS group), and 30 children received, in addition, a posterior reduction and transpedicular instrumentation (posteroanterior spondylodesis, PAS group). RESULTS: Distribution of age, gender, preoperative clinical symptoms, and preoperative radiologic classification of the spondylolisthesis were comparable in both groups (average degree of slip for the AS group, 66%; that for the PAS group, 75%; angle of slip, 28 degrees and 36 degrees, respectively; sacral inclination, 31 degrees and 25 degrees, respectively). The postoperative follow-up period of the AS group lasted 125 +/- 22 months, considerably longer than that of the PAS group at 67 +/- 20 months. At the time of the follow-up assessment, the PAS group showed a reduced rate of pseudarthrosis (7% versus 24%), a reduced degree of slip (36% versus 59%), and a reduced lumbosacral kyphosis (14 degrees versus 26 degrees) in comparison with the AS group. The transpedicular instrumentation decreased the fusion time of osseous consolidation of the spondylodesis markedly (7 months versus 17 months, on average). Adverse effects and rate of complications were equal in both groups. The results failed to show any differences in favor of either of the two surgical techniques used either subjectively to the patient or objectively by means of clinical examination. CONCLUSION: Anterior spondylodesis including posterior instrumentation and reduction was superior to the simple anterior fusion in situ for normalization of the lumbosacral profile and osseous consolidation of the spondylodesis. This result was not reflected in the clinical evaluation.

[Experimental studies of mechanically-induced articular cartilage defects following implantation of allogeneic embryonal chondrocytes in a collagen-fibrin gel in chickens]. / Experimentelle Untersuchungen mechanisch induzierter Gelenkknorpeldefekte nach Implantation allogener embryonaler Chondrozyten in einem Kollagen-Fibrin-Gel beim Huhn.

Full thickness defects (diameter 1,7 mm; depth 2,5 mm) were created mechanically in articular cartilage and subchondral bone of the condyles of tibiotarsal joints of 9-month old chickens. This full-thickness defects were repaired with cultured allogenic embryonic chick epiphyseal chondrocytes from the tibiae and femura of 10-days-old chicken embryos. The cells were embedded in a collagen-fibrinogen-matrix. Controls were similarly operated, but received either no treatment or implants the delivery substance only. Healing of the defects was observed macroscopically, histologically, histochemically and histomorphometrically after 3, 12 and 24 weeks. This graft was successfully transplanted in mechanically induced defects in 80%. The resulting hyaline cartilage was structurally reorganized according to the host pattern and under the influence of environmental conditions. The articular zone preserved it's cartilaginous phenotype, whereas the subchondral regions were transformed into bone. 12 weeks after the operation the defects in the experimental group were completely filled. In all instances in this group, there was an initial extreme increase of mitotic rate and cell number. After 24 weeks normal and subnormal values were founded. The defects in the control groups healed with fibrocartilage. Our results showed, that only the defects in the experimental group were completely filled with reparative hyaline cartilage tissue. In the present study the mixture of cultured allogenic embryonic chondrocytes and a collagen-fibrinogen-matrix was used successfully as a transplant for repairing defects in articular cartilage of chickens. Thus allogenic transplantation of cultured embryonal chondrocytes appears to be one of the most promising methods for the restoration of articular cartilage.

Competitive sports and the progression of spondylolisthesis.

To consider the effects of several years of competitive sports training on children and adolescents with spondylolisthesis, we carried out a retrospective radiologic and clinical study of 86 young athletes with spondylolysis or spondylolisthesis (24 girls and 62 boys between the ages of 6 and 20 years). The mean degree of displacement was 10.1% at the beginning of the observation. The radiologic tests showed an increase in displacement over time in 33 athletes. The average progression of spondylolisthesis in this group was 10.5%. For 36 athletes, spondylolisthesis did not progress during the period of athletic training. In seven athletes, a decrease in the displacement was observed, from 17.9 to 8.9% on average. For 10 athletes, the course of spondylolisthesis could not be determined, because only one lateral radiograph was available. In spite of intensive daily training, the athletes had no symptoms during the entire period of observation, which lasted an average of 4.8 years. In light of our experiments, there is no justification for generally advising children and adolescents with limited spondylolytic spondylolisthesis not to take part in competitive sports.

Operative treatment of adolescent idiopathic thoracic scoliosis. Harrington-DTT versus Cotrel-Dubousset instrumentation.

Radiographic outcome and complications of Harrington-DTT (H) and Cotrel-Dubousset (CD) instrumentation of idiopathic adolescent thoracic scoliosis were compared retrospectively. The patient material consists of 55 consecutive patients in the H group and 52 consecutive patients in the CD group. The mean age at operation was 15 +/- 2 years (range, 11-19 years) in both groups. The follow-up interval was 43 +/- 18 months (range, 17-91 months) in the H group and 28 +/- 11 months (range, ten to 53 months) in the CD group (p = 0.0001). The preoperative radiographic measurements (Cobb angle of primary and secondary curve, apical rotation, thoracic kyphosis, lumbar lordosis) were fully comparable in both groups. The mean correction of the primary curve at the follow-up evaluation was 47% in both groups. Apical rotation of the primary curve remained almost unchanged in both groups. Rotation of the secondary curve increased significantly in the CD group. Thoracic kyphosis was unchanged in the CD group but decreased in the H group. Spinal balance worsened in 29% of the H cases and in 44% of the CD cases. There were no neurologic complications in either of the groups. Intraoperative lamina fractures (four cases) and postoperative hook dislodgement (five cases) occurred only in the CD group. One distraction rod breakage occurred in the H group. Three reoperations were performed in the H group, nine in the CD group.

[Measurement data of the lateral lumbosacral region in healthy subjects during the growth period]. / Messwerte der seitlichen Lumbosakralregion bei Normalpersonen im Wachstumsalter.

The following measurement data were obtained to characterise the healthy lumbosacral profile, via lateral x-rays taken of 90 female and 90 male patients between 8 and 17 years of age: Degree of slip 0%, slip angle -21.3 degrees, sacral inclination 45.5 degrees, posterior lumbosacral angle 140.5 degrees. These measurement data are independent of age and sex. If an adolescent suffers from lumbosacral spondylolisthesis, they will quantify the process of slip that has taken place, more accurately than the conventional method after Meyerding. If the shape of the sacral vertebra is considered at the same time, these parameters will also enable to assess the risk of progression of spondylolisthesis to a degree that is satisfactorily accurate in clinical practice.

[Lumbar segmental spondylodesis--isolated ventral or combined dorsoventral? A comparison of results]. / Lumbale Segmentspondylodese--isoliert ventral oder kombiniert dorsoventral? Ein Ergebnisvergleich.

Indications for intercorporal fusion are progressive spondylolisthesis in children and adolescents, painful segmental instability in adults (spondylolisthesis, post-discectomy-syndrome, failed-back-syndrome). From 1980-86 152 isolated anterior intercorporal fusions had been realized, and in 1987/88 we carried out 79 combined anterior-posterior fusions. The rate of pseudarthrosis has been 25% with isolated anterior fusion and on the contrary 9% with combined fusion. With combined fusion the rate of complications did not increase, but the objective and subjective results became better. The postoperative period became more convenient, the stay in hospital and the consolidation of fusion were shorter. The reposition of spondylolisthesis was durable and the spine channel was accessible. We consider the instrumented fusion to be a complex reconstructive operation with high chances of success.