[Posterior instrumented correction and fusion of adolescent idiopathic scoliosis]

OBJECTIVE

Balanced frontal curve correction with horizontal shoulder levels, restoration of sagittal plane and vertebral derotation with a fusion length as short as possible.

INDICATIONS

Curves larger than 40-50° Cobb angle; furthermore age, location, degree of rotation, and sagittal plane deviation have to be considered.

SURGICAL TECHNIQUE

Posteriorly, segmental pedicle screw instrumentation with a high screw density (80%) and both titanium alloy and cobalt chrome rods. Freehand screw placement under consideration of both natural and deformity-induced pedicle morphology. Correction via reduction screws or instruments. Combined correction technique with rod rotation, segmental screw approximation to the generally concave rod and segmental correction of vertebral translation. Moderate concave distraction and convex compression. If needed, final in situ bending of the rods. Schwab type I osteotomies; in rigid curves type II osteotomies. Fusion with local bone, allogenic bone and/or bone substitutes (i.e., tricalcium phosphate). Intraoperative placement of a thoracic epidural catheter for postoperative pain control. Neurological monitoring throughout the procedure.

POSTOPERATIVE MANAGEMENT

Mobilization on postoperative day 1 with focus on pain management and nutrition. Return to school after 4 weeks. Physiotherapy after 3 months, cycling after 3-6 months, and full sport activities after 1 year.

RESULTS

Frontal curve correction of 60-80%, sufficient sagittal plane correction. Correction of rib hump 40%. Patient satisfaction is high at 95% and long-term revision rates of < 10%.

Analysis of the Spinopelvic Parameters in Patients with Fragility Fractures of the Pelvis

BACKGROUND

We investigated the spinopelvic parameters of lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS) in patients with fragility fractures of the pelvis (FFPs). We hypothesized that these parameters differ from asymptomatic patients.

METHODS

All patients treated for FFPs in a center of maximal care of the German Spine Society (DWG) between 2017 and 2021 were included. The inclusion criteria were age ≥ 60 years and the availability of a standing lateral radiograph of the spine and pelvis in which the spine from T12 to S1 and both femoral heads were visible. The baseline characteristics and study parameters were calculated and compared with databases of asymptomatic patients. The two-sample t-Test was performed with p < 0.05.

RESULTS

The study population (n = 57) consisted of 49 female patients. The mean age was 81.0 years. The mean LL was 47.9°, the mean PT was 29.4°, the mean SS was 34.2° and the mean PI was 64.4°. The mean value of LLI was 0.7. LL, LLI and SS were significantly reduced, and PI and PT were significantly increased compared to asymptomatic patients.

CONCLUSIONS

The spinopelvic parameters in patients with FFPs differ significantly from asymptomatic patients. In patients with FFPs, LL, LLI and SS are significantly reduced, and PI and PT are significantly increased. The sagittal spinopelvic balance is abnormal in patients with FFPs.

Efficacy of a 4-Antigen Staphylococcus aureus Vaccine in Spinal Surgery: The STRIVE Randomized Clinical Trial

BACKGROUND

Staphylococcus aureus is a global pathogen frequently responsible for healthcare-associated infections, including surgical site infections (SSIs). Current infection prevention and control approaches may be limited, with S aureus antibiotic resistance remaining problematic. Thus, a vaccine to prevent or reduce S aureus infection is critically needed. This study evaluated efficacy and safety of an investigational 4-antigen S aureus vaccine (SA4Ag) in adults undergoing elective open posterior spinal fusion procedures with multilevel instrumentation.

METHODS

In this multicenter, site-level, randomized, double-blind trial, subjects 18-85 years old received a single dose of SA4Ag or placebo 10-60 days before surgery. SA4Ag efficacy in preventing postoperative S aureus bloodstream infection and/or deep incisional or organ/space SSI was the primary endpoint. Safety evaluations included local reactions, systemic events, and adverse events (AEs). Immunogenicity and colonization were assessed.

RESULTS

Study enrollment was halted when a prespecified interim efficacy analysis met predefined futility criteria. SA4Ag showed no efficacy (0.0%) in preventing postoperative S aureus infection (14 cases in each group through postoperative Day 90), despite inducing robust functional immune responses to each antigen compared with placebo. Colonization rates across groups were similar through postoperative Day 180. Local reactions and systemic events were mostly mild or moderate in severity, with AEs reported at similar frequencies across groups.

CONCLUSIONS

In patients undergoing elective spinal fusion surgical procedures, SA4Ag was safe, well tolerated, but despite eliciting substantial antibody responses that blocked key S aureus virulence mechanisms, was not efficacious in preventing S aureus infection. ClinicalTrials.gov: NCT02388165.

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.

Complications in TLIF spondylodesis-do they influence the outcome for patients? A prospective two-center study

PURPOSE

Transforaminal lumbar interbody fusion (TLIF) is a widely accepted surgical procedure for degenerative disk disease. While numerous studies have analyzed complication rates and risk factors this study investigates the extent to which complications after TLIF spondylodesis alter the clinical outcome regarding pain and physical function.

METHODS

A prospective clinical two-center study was conducted, including 157 patients undergoing TLIF spondylodesis with 12-month follow-up (FU). Our study classified complications into three subgroups: none (I), minor (IIa), and major complications (IIb). Complications were considered "major" if revision surgery was required or new permanent physical impairment ensued. Clinical outcome was assessed using visual analog scales for back (VAS-B) and leg pain (VAS-L), and Oswestry Disability Index (ODI).

RESULTS

Thirty-nine of 157 patients (24.8%) had at least one complication during follow-up. At FU, significant improvement was seen for group I (n = 118) in VAS-B (-50%), VAS-L (-54%), and ODI (-48%) and for group IIa (n = 27) in VAS-B (-40%), VAS-L (-64%), and ODI (-47%). In group IIb (n = 12), VAS-B (-22%, P = 0.089) and ODI (-33%, P = 0.056) improved not significantly, while VAS-L dropped significantly less (-32%, P = 0.013) compared to both other groups.

CONCLUSION

Our results suggest that major complications with need of revision surgery after TLIF spondylodesis lead to a significantly worse clinical outcome (VAS-B, VAS-L, and ODI) compared to no or minor complications. It is therefore vitally important to raise the surgeon´s awareness of consequences of major complications, and the topic should be given high priority in clinical work.

Current surgical strategies for treating spinal tumors: Results of a questionnaire survey among members of the German Spine Society (DWG)

PURPOSE

Questionnaire survey among the members of the German Spine Society (Deutsche Wirbelsäulen-Gesellschaft, DWG) to objectify oncological infrastructure and current standard of care in spinal tumor treatment in Germany.

METHODS

All DWG-members were contacted via the society's e-mail and asked to respond in anonymized form to a related questionnaire. Questions were asked regarding surgical specialty, type of institution involved, numbers of spinal procedures, as well as questions on treatment for primary tumors, whether the respondent belonged to a tumor center, decision-making procedures for surgery, and the type of procedure.

RESULTS

84 centers providing surgical treatment for spinal tumors in their departments were identified. 52.6% were carrying out more than 500 spinal procedures per year. There was a significant association (P ≤ 0.05) between the numbers of spinal surgeries, the number of treated tumor patients per year, the organisation in a tumor center and the treatment of primary tumors. 76% are part of a local tumor center for interdisciplinary decision making (i.e.surgical treatment and adjuvant therapy). 74% of the institutions stated that conventional postoperative radiotherapy is standardly administered in the case of secondary lesions, with 24% of them referring patients to external services for radiotherapy.

CONCLUSION

In spite of often large numbers of spinal operations, the centers perform relatively small numbers of tumor operations, particularly for primary tumors. A nearly three-quarter majority of the departments are integrated into interdisciplinary tumor care. However, there is a marked number that do not belong to an interdisciplinary organisation. Further advances in multidisciplinarity and oncology training are a continuous issue to increase treatment quality in spinal tumor patients.

Intra- versus postoperative initiation of pain control via a thoracic epidural catheter for lumbar spinal fusion surgery

BACKGROUND

Thoracic epidural anesthesia (TEA) is one of the pillars of perioperative pain care. Particularly for spine surgery which causes significant postoperative pain TEA seems like an appealing option. However, beneficial effects of a TEA are questionable when the catheter is not used intraoperatively, a decision that is usually based on the surgeon's wish to perform immediate neurological examination postoperatively.

METHODS

Forty patients undergoing transforaminal lumbar interbody fusion surgery (TLIF) were randomized into two groups. Patients received preoperative insertion of a TEA. For patients in the intraoperative group an epidural infusion was started preoperatively and maintained throughout. For patients in the postoperative group the epidural infusion was started once neurological examination had been performed. The primary outcome measure in this study was postoperative requirements of piritramide during the first two postoperative hours. Secondary outcomes involved postoperative pain numeric rating scale (NRS) scores, intraoperative opioid requirements, side effects and ability to perform direct postoperative neurological examination.

RESULTS

Postoperative group patients required significantly more opioids both intra- and postoperatively (P=0.036 and P=0.039) and NRS scores were significantly higher on admission to recovery, at 30 and 60 min as compared to patients in the intraoperative group (P=0.013; P=0.004 and P=0.012). Early postoperative neurological examination was feasible in all patients in both groups.

CONCLUSIONS

Epidural catheters used intraoperatively during TLIF are feasible, significantly reduce pain, intra- and postoperative use of opioids and do not influence the quality of neurological tests directly after the surgical procedure.

[Cement augmentation of pedicle screws : Pros and cons]

Cement augmentation of pedicle screws biomechanically increases screw purchase in the bone. However, clinical complications may occur. The pros and cons of the technique are discussed from different clinical perspectives.

Vaccine development to prevent Staphylococcus aureus surgical-site infections

BACKGROUND

Staphylococcus aureus surgical-site infections (SSIs) are a major cause of poor health outcomes, including mortality, across surgical specialties. Despite current advances as a result of preventive interventions, the disease burden of S. aureus SSI remains high, and increasing antibiotic resistance continues to be a concern. Prophylactic S. aureus vaccines may represent an opportunity to prevent SSI.

METHODS

A review of SSI pathophysiology was undertaken in the context of evaluating new approaches to developing a prophylactic vaccine to prevent S. aureus SSI.

RESULTS

A prophylactic vaccine ideally would provide protective immunity at the time of the surgical incision to prevent initiation and progression of infection. Although the pathogenicity of S. aureus is attributed to many virulence factors, previous attempts to develop S. aureus vaccines targeted only a single virulence mechanism. The field has now moved towards multiple-antigen vaccine strategies, and promising results have been observed in early-phase clinical studies that supported the recent initiation of an efficacy trial to prevent SSI.

CONCLUSION

There is an unmet medical need for novel S. aureus SSI prevention measures. Advances in understanding of S. aureus SSI pathophysiology could lead to the development of effective and safe prophylactic multiple-antigen vaccines to prevent S. aureus SSI.

Spontaneous lumbar curve correction in selective anterior instrumentation and fusion of idiopathic thoracic scoliosis of Lenke type C

BACKGROUND

Posterior pedicle screw instrumented correction and fusion have become the gold standard in the surgical treatment of thoracic scoliosis. However, in thoracic Lenke type C curves selective posterior fusion of the thoracic curve may lead to spinal imbalance. The aim of the study was to analyse the radiological results of selective anterior thoracic fusion using a standard open dual rod technique with special respect to spontaneous lumbar curve correction (SLCC).

METHODS

Twenty-eight patients (26 patients with Lenke 1C and 2 patients with Lenke 2C curves) with an average age of 15 years were surgically treated with an anterior dual rod system through a standard open double thoracotomy approach. Average clinical and radiological follow-up was 4 years (24-84 months).

RESULTS

Fusion was carried out mostly from end-to-end vertebra. The primary curve was corrected from 61.6° (average correction on reverse bending films 42.9 %) to 27.1° (56.0 % correction) with an average loss of correction of 2.2°. The secondary lumbar curve measured 47.7° preoperatively (40-56°, average correction on reverse bending films 66.2 %) and corrected spontaneously to 30.1° (36 % SLCC) and remained stable without any cases of deterioration or decompensation during follow-up. Lumbar apical vertebral translation increased minimally by an average of 4 mm directly, postoperatively, and returned to an average of preoperative values during follow-up. All but two curves remained as type C lumbar modifier at follow-up. Preoperatively, three patients showed a marked coronal imbalance of more than 3 cm (all left, average 4.0 cm); at follow-up, two patients were still out of balance by more than 3 cm (all to the left, average 3.4 cm). Preoperatively, a marked shoulder imbalance of more than 1.0 cm was found in 11 patients; this was corrected in all patients to <1.0 cm at follow-up. The apical vertebral rotation measured according to Perdriolle was corrected from 23.5° to 15.0° in the thoracic spine (36.2 % correction) with an average clinical reduction of the rib hump of 63.2 %. In the lumbar spine, there was no relevant radiological derotation; however, clinically, the lumbar hump corrected spontaneously by 44.3 %. Thoracic kyphosis measured 28.5° preoperatively and 32.3° at follow-up. All six patients with a preoperative hypokyphosis (<20°) of an average of 9.5° were successfully corrected to an average thoracic kyphosis of 23.8° at follow-up. There were no cases of junctional thoracolumbar kyphosis. There were neither reoperations nor implant failures with pseudarthrosis.

CONCLUSION

Selective anterior correction and fusion in primary thoracic curves with lumbar modifier type Lenke C resulted in a reliable and satisfactory SLCC. Advantages of anterior versus posterior techniques are the true segmental derotation with excellent rib hump correction and a superior restoration of thoracic kyphosis.

Sagittal balance of thoracic lordoscoliosis: anterior dual rod instrumentation versus posterior pedicle screw fixation

Posterior pedicle screw fixation is now the standard treatment for surgical correction of idiopathic scoliosis and has largely replaced anterior techniques, but there have been reports describing a lordogenic effect of segmental pedicle screw instrumentation in the thoracic spine. This clinical study compared anterior dual rod instrumentation with posterior pedicle screw fixation for idiopathic thoracic lordoscoliosis, including 42 patients (7 male, 35 female; average age 16 years, range 12-34) who underwent posterior pedicle screw fixation (n = 20) or anterior dual rod instrumentation (n = 22) at two centers. The average follow-up period was 33 months (24-108 months). Inclusion criteria were a diagnosis of adolescent idiopathic scoliosis with a structural thoracic curve (Lenke 1-3) and thoracic hypokyphosis (T4-T12 < 20°). The main thoracic curve magnitude and sagittal profile on standing radiographs were evaluated. Thoracic kyphosis was significantly restored from preoperatively 10.2° to 23.4° postoperatively in the anterior group and from 7.6° to 12.9° in the posterior group (P < 0.005). Kyphosis improved significantly better in the anterior group than in the posterior group (P < 0.005). The preoperative and postoperative main thoracic curve values were 63° (48-80°) and 25.2° in the anterior group and 60.6° (50-88°) and 23.6° in the posterior group, with no significant differences between the groups. No neurological or other severe complications were observed. Anterior dual rod instrumentation in patients with thoracic lordoscoliosis allows significantly better restoration of thoracic kyphosis than posterior pedicle screw instrumentation.

Left convex thoracic scoliosis: retrospective analysis of 25 patients after surgical treatment

OBJECTIVE: A retrospective analysis of clinical and radiological data was conducted, with an emphasis on perioperative complications and risk factors and a minimum follow-up period of two years. The postoperative quality of life was assessed using the SRS-22 questionnaire. METHODS: Between 1999 and 2009, 25 patients (nine male, 16 female) with LCTS, with a mean age of 13.7 years (2.3-29.8 years), were treated with correction and instrumented fusion at a single institution. Seven patients had congenital scoliosis and 18 patients had noncongenital scoliosis (idiopathic, n = 5; neuropathic, n = 4; neoplasm-associated/iatrogenic, n = 3; secondary to other conditions, n = 6). The average preoperative Cobb angle was 74° (49-102°). RESULTS: A mean correction of 51% was achieved postoperatively. The mean Cobb angle at the final follow-up examination was 45° (19-85°), with a significant loss of correction of 8.8° on average. Major complications affected five patients (20%): respiratory insufficiency requiring prolonged intubation, intraoperative cardiac arrest with resuscitation being necessary twice in one patient, persistent clonus, low-grade infection, implant-based complications requiring revision surgery, and adding-on. Minor complications were observed in 22 patients (88%), mainly gastrointestinal and pulmonary. No cases of paraplegia or death occurred. A noncongenital etiology had been diagnosed before the age of 10 years in all of the patients who had major complications. The best score on the SRS-22 questionnaire was achieved in the domain of pain (87%), while the poorest was in the domain of self-image (68%). CONCLUSIONS: The results of this study emphasize an increased complication rate in patients with LCTS scheduled for scoliosis surgery. Additional preoperative examinations (MRI, paediatric consultation, cardiologic consultation, pulmonary function test) are mandatory in patients with LCTS. Preoperatively, patients should be informed about the increased cardiopulmonary and neurological risk which may be associated with scoliosis surgery.

Approach-related lesions of the sympathetic chain in anterior correction and instrumentation of idiopathic scoliosis

During anterior scoliosis instrumentation with a dual-rod system, the vertebrae are dissected anterolaterally. After surgery, some patients report a change in temperature perception and perspiration in the lower extremities. Sympathetic lesions might be an explanation for this. The aim of this clinical study was to investigate sympathetic function after anterior scoliosis instrumentation. A total of 24 female patients with idiopathic scoliosis (mean age at follow-up, 23.8 years) who had undergone anterior instrumentation on average 6.6 years earlier were included. Due to the suspected relevance of the sympathetic L2 ganglion, two groups were created: a T12 group, in which instrumentation down to T12 was carried out (n = 12), and an L3 group, in which instrumentation down to L3 was done (n = 12). Sympathetic function was assessed by measuring skin temperature at the back of the foot, a plantar ninhydrin sweat test and sympathetic skin responses (SSRs) following electrical stimulation. The side on which the surgical approach was carried out was compared with the contralateral, control side. Health-related quality of life was investigated using the Scoliosis Research Society SRS-22 patient questionnaire. In the T12 group, mean temperatures of 29.6 degrees C on the side of the approach versus 29.5 degrees C on the control side were measured (P > 0.05); in the L3 group, the mean temperatures were 33.2 degrees C on the approach side versus 30.5 degrees C on the control side (P = 0.001). A significant difference between the T12 group and the L3 group (P < 0.001) was observed on the approach side, but not on the control side (P = 0.15). The ninhydrin sweat test showed reduced perspiration in 11 of 12 patients in the L3 group on the approach side in comparison with the control side (P = 0.002). In the T12 group, no significant differences were noted between the left and right feet. SSRs differed significantly between the two groups (P = 0.005). They were detected in all nine analyzable patients in the T12 group on both sides. In the L3 group, they were found on the approach side only in 4 of 11 analyzable patients versus 11 patients on the control side. The results of the SRS-22 questionnaire did not show any significant differences between the two groups. In conclusion, anterior scoliosis instrumentation with a dual-rod system including vertebrae down to L3 regularly leads to lesions in the sympathetic trunk. These are detectable with an increase in temperature, reduced perspiration and reduced SSRs. The caudal level of instrumentation (T12 vs. L3) has an impact on the extent of impairment, supporting the suspected importance of the L2 ganglion. The clinical outcome does not seem to be significantly limited by sympathetic trunk lesions.

[Selective fusion of idiopathic scoliosis with respect to the Lenke classification]

Indications for surgical treatment of idiopathic scoliosis are progressive curves greater than 40-50 degrees. In most cases, fusion of only the primary (structural) curve(s) is sufficient due to the flexibility and spontaneous correction of the secondary curves. Therefore, it is crucial to identify both primary and secondary curves. According to the Lenke classification, all curves with a residual curve of more than 25 degrees on the bending films and those with a pathological kyphosis are regarded as structural and should be fused, whereas the nonstructural curves can be left unfused. However, according to reports in the literature and to the author's experience, clinical parameters such as shoulder level and rib or lumbar hump as well as radiometric criteria such as rotation are relevant as well. In summary, the Lenke classification is an important and helpful tool for analysing idiopathic curves and determining fusion length, even though each scoliosis case needs to be evaluated individually, especially taking clinical parameters into account.

Creation of a head and face protection device for children undergoing procedures in prone position

BACKGROUND

Positioning the head of patients undergoing procedures in lateral or prone position remains a difficult task for the anesthesiologists. Associated risks have attracted increasing attention because they range from minor facial soft tissue injuries to catastrophic complications such as stroke or postoperative blindness. Earlier, we reported on the use of a boxing sports helmet for simple and easy positioning of the head. However, as available helmets are limited in sizes and materials, that system is not easily transferable to children. Therefore, we sought to create a face and head protection device for children undergoing procedures in prone position.

METHODS/MATERIALS

We re-engineered a standard boxing sports helmet making it suitable as an on-head support cushion. By using WHO standard growth charts, various sizes were calculated and prototypes of different foam materials produced. Facial surface pressures were measured in 15 volunteers.

RESULTS

A lightweight foam-based face mask was created. Minimum necessary foam thickness was 2.5 cm. Different materials were tested and pressure in different facial zones never exceeded 30 mmHg.

CONCLUSION

Bringing a face protection device onto the patient's face instead of placing the face into support cushions is an elegant way of keeping control over airway devices and providing support for facial structures in various positions simultaneously. Skin surface pressure on facial structures remained low due to the specific mask design and choice of foam materials, which could lead to decreased incidences of undesired sequelae of prone position such as skin damage or even more devastating complications.

[Scoliosis surgery in children from the viewpoint of anaesthesiology]

Anaesthesia for scoliosis surgery in children is a challenge for the paediatric anaesthesiologist. The large range of underlying pathologies causing deranged physiology in an inhomogeneous patient group ranging from neonates to adolescents necessitates diligent and individual preparation for each case. Due to the invasiveness of the operation demanding anaesthetic care is necessary. This review highlights current approaches to monitoring, anaesthetic regimen, positioning of the patient, blood conservation and transfusion, age-related pathophysiology, ventilation and postoperative pain therapy. The introduction of neurophysiologic spinal cord monitoring requires certain adaptations of the anaesthetic regimen to suit technological advances.

A level-1 pilot study to evaluate of ultraporous beta-tricalcium phosphate as a graft extender in the posterior correction of adolescent idiopathic scoliosis

The objective of this study is to compare the clinical and radiographic results of ultraporous beta-tricalcium phosphate (beta-TCP) versus autogenous iliac crest bone graft (ICBG), through prospective randomized pilot study (EBM-Level 1), as graft extenders in scoliosis surgery. In the posterior correction of scoliosis, local bone resected as part of the procedure is used as the base bone graft material. Supplemental grafting from the iliac crest is considered the gold-standard in posterior spinal fusion. However, autograft is not available in unlimited quantities, and bone harvesting is a source of significant morbidity. Ultraporous beta-TCP might be a substitute for ICBG in these patients and thus eliminate donor site morbidity. A total of 40 patients with adolescent idiopathic scoliosis (AIS) were randomized into two treatment groups and underwent corrective posterior instrumentation. In 20 patients, ICBG harvesting was performed whereas the other half received beta-TCP (VITOSS) to augment the local bone graft. If thoracoplasty was performed, the resected rib bone was added in both groups. Patients were observed clinically and radiographically for a minimum of 20 months postoperatively, with a mean follow-up of 4 years. Overall pain and pain specific to the back and donor site were assessed using a visual analog scale (VAS). As a result, both groups were comparable with respect to the age at the time of surgery, gender ratio, preoperative deformity, and hence length of instrumentation. There was no significant difference in blood loss and operative time. In nine patients of the beta-TCP group and eight patients of the ICBG group, thoracoplasty was performed resulting in a rib graft of on average 7.9 g in both groups. Average curve correction was 61.7% in the beta-TCP group and 61.2% in the ICBG group at hospital discharge (P=0.313) and 57.2 and 54.3%, respectively, at follow-up (P=0.109). Loss of curve correction amounted on average 2.6 degrees in the beta-TCP group and 4.2 degrees in the comparison group (P=0.033). In the ICBG group, four patients still reported donor site pain of on average 2/10 on the VAS at last follow-up. One patient in the beta-TCP group was diagnosed with a pseudarthrosis at the caudal end of the instrumentation. Revision surgery demonstrated solid bone formation directly above the pseudarthrosis with no histological evidence of beta-TCP in the biopsy taken. In conclusion, the use of beta-TCP instead of ICBG as extenders of local bone graft yielded equivalent results in the posterior correction of AIS. The promising early results of this pilot study support that beta-TCP appears to be an effective bone substitute in scoliosis surgery avoiding harvesting of pelvic bone and the associated morbidity.

Hemihyperplasia-multiple lipomatosis syndrome (HHML): a challenge in spinal care

A 15-year-old girl developed a progressive paraparesis over a period of six months, secondary to spinal cord compression by a lipomatous mass and anomalies of the vertebral column. Clinically, a right hemihyperplasia affecting the trunk and lower limb was evident, as well as a right convex lumbar scoliosis. CT and MRI demonstrated severe spinal cord compression resulting from intraspinal lipomatosis, overgrowth of right facet joints (T8 to L5), and kyphoscoliosis. Surgical decompression was undertaken. A lumbar scoliosis of 48 degrees was partially corrected by means of dual-rod instrumentation. The neurological deficit improved significantly, and ambulation was progressively restored. The patient carried the diagnosis of Proteus syndrome for several years, but reevaluation of clinical features prompted the diagnosis of Hemihyperplasia Multiple Lipomatosis syndrome (HHML). This rare sporadic disorder is often confused with Proteus syndrome. As in Proteus syndrome, spinal cord compression in patients with HHML can result from lipomatous infiltration and/or significant spinal abnormalities including kyphoscoliosis and overgrowth. HHML and Proteus syndrome are discussed and compared with special emphasis on spinal and orthopaedic pathologies.

[En-bloc spondylectomy and reconstruction for primary tumors and solitary metastasis of the spine]

In primary tumors of the spine and, with limitations, solitary metastasis, the surgical approach should aim for curative treatment of the disease. Because the prognosis of malignant bone tumors is extremely limited, if an intralesional approach is performed, an extralesional en bloc resection is the treatment of choice. Therefore, it is mandatory to use an appropriate staging system. For the spine, the WBB staging system has been approved, which transfers the principles of the Enneking classification for treating primary malignant tumors of the limb to the spine. After en bloc spondylectomy, rigid and primary stable instrumented dorsoventral reconstruction must be performed - posteriorly with a dual-rod system using pedicle screws, and anteriorly in the ideal case by means of a vertebral body replacement cage. The possibility of extralesional (wide or marginal) resection of spinal tumors depends on tumor size and location. Extralesional resection and, if indicated, other neoadjuvant, adjuvant, or local therapeutic modalities have a strong positive influence on long-term survival rates. A good prognosis for primary tumors is associated with a good response to chemotherapy and extralesional resection. Solitary metastases have a much worse quod vitam prognosis. Therefore, local control of the disease in en bloc resections of solitary metastasis is a second relevant goal, although curative treatment is the primary aim.

The effect of dynamic, semi-rigid implants on the range of motion of lumbar motion segments after decompression

Undercutting decompression is a common surgical procedure for the therapy of lumbar spinal canal stenosis. Segmental instability, due to segmental degeneration or iatrogenic decompression is a typical problem that is clinically addressed by fusion, or more recently by semi-rigid stabilization devices. The objective of this experimental biomechanical study was to investigate the influence of spinal decompression alone, as well as in conjunction with two semi-rigid stabilizing implants (Wallis, Dynesys) on the range of motion (ROM) of lumbar spine segments. A total of 21 fresh-frozen human lumbar spine motion segments were obtained. Range of motion and neutral zone (NZ) were measured in flexion-extension (FE), lateral bending (LAT) and axial rotation (ROT) for each motion segment under four conditions: (1) with all stabilizing structures intact (PHY), (2) after bilateral undercutting decompression (UDC), (3) after additional implantation of Wallis (UDC-W) and (4) after removal of Wallis and subsequent implantation of Dynesys (UDC-D). Measurements were performed using a sensor-guided industrial robot in a pure-moment-loading mode. Range of motion was defined as the angle covered between loadings of -5 and +5 Nm during the last of three applied motion cycles. Untreated physiologic segments showed the following mean ROM: FE 6.6 degrees , LAT 7.4 degrees , ROT 3.9 degrees . After decompression, a significant increase of ROM was observed: 26% FE, 6% LAT, 12% ROT. After additional implantation of a semi-rigid device, a decrease in ROM compared to the situation after decompression alone was observed with a reduction of 66 and 75% in FE, 6 and 70% in LAT, and 5 and 22% in ROT being observed for the Wallis and Dynesys, respectively. When the flexion and extension contribution to ROM was separated, the Wallis implant restricted extension by 69% and flexion by 62%, the Dynesys by 73 and 75%, respectively. Compared to the intact status, instrumentation following decompression led to a ROM reduction of 58 and 68% in FE, 1 and 68% in LAT, -6 and 13% in ROT, 61 and 65% in extension and 54 and 70% in flexion for Wallis and Dynesys. The effect of the implants on NZ corresponded to that on ROM. In conclusion, implantation of the Wallis and Dynesys devices following decompression leads to a restriction of ROM in all motion planes investigated. Flexion-extension is most affected by both implants. The Dynesys implant leads to an additional strong restriction in lateral bending. Rotation is only mildly affected by both implants. Wallis and Dynesys restrict not only isolated extension, but also flexion. These biomechanical results support the hypothesis that postoperatively, the semi-rigid implants provide a primary stabilizing function directly. Whether they can improve the clinical outcome must still be verified in prospective clinical investigations.

En bloc spondylectomy in malignant tumors of the spine

En bloc spondylectomy is a technique that enables wide or marginal resection of malignant lesions of the spine. Both all posterior techniques as well as combined approaches are reported. Aim of the present study was to analyse the results of 21 patients with malignant lesions of the spine, all treated with en bloc excision in a combined posteroanterior (n = 19) or all posterior approach (n = 2). Twenty-one consecutive patients, operated between 1997 and 2005, were included into this retrospective study. Thirteen patients had primary malignant lesions, eight patients had solitary metastases, all located in the thoracolumbar spine. There were 16 single level, three two-level, one three-level and one four-level spondylectomy. The patients were followed clinically and radiographically (including CT studies) with an average follow-up of 4 years. Out of 11 patients with primary Ewing or osteosarcoma seven patients are alive without any evidence of disease. One patient died after 5 years from other causes and three are alive with evidence of disease. Latter had either a poor histologic response to the preoperative chemotherapy (n = 2) or an intralesional resection (n = 1). All three patients with solitary spinal metastases of Ewing or osteosarcoma died of the disease. Five patients with solitary metastases of mainly hypernephroma are alive. In total, six resections were intralesional, mainly due to large intraspinal tumor masses, with two patients having had previous surgery. In the remaining cases, wide (n = 10) or marginal (n = 5) resection was accomplished. There were one pseudarthrosis requiring extension of the fusion and two cases with local recurrences and repeated excisional surgery. At follow-up CT studies, all cages were fused. Health related quality of life analysis (SF-36) revealed only slightly decreased physical component and normal mental component scores compared to normals in those patients with no evidence of disease. En bloc spondylectomy enables wide or marginal resection of malignant lesions of the spine in most cases with acceptable morbidity. Intralesional resection, poor histologic response, and solitary spinal metastases of Ewing and osteosarcoma are associated with a poor prognosis.

Changes in disc height and posteroanterior displacement after fusion in patients with idiopathic scoliosis: a 9-year follow-up study

INTRODUCTION

In scoliosis patients treated with long segment spinal fusion, degenerative changes like retrolisthesis and disc space narrowing below fusion have been observed. However, there is disagreement concerning their incidence and dependency on the location of the lowest instrumented vertebra.

MATERIALS AND METHODS

To evaluate temporal changes in disc height and posteroanterior displacement (indicating listhesis) below fusion, 40 patients with adolescent idiopathic scoliosis, mainly treated with Cotrel-Dubousset instrumentation, were retrospectively investigated in this longitudinal study with a follow-up of on average 9.2 years (median 9.4 y) after surgery. Disc height and displacement were measured from lateral radiographs by means of distortion-compensated roentgen analysis (DCRA). Additionally, a mathematical model was developed to determine the influence of vertebral tilt in scoliosis on disc height and displacement.

RESULTS

Overall, no significant decrease in disc height was observed during follow-up. Concerning listhesis a small but significant retrolisthesis was found in segments L2/L3 and L3/L4. Compared with normative data, there was no significant listhesis for the L5/S1 segment. Nevertheless, separating the study group into subsamples of identical distal fusion level revealed a significant correlation between the amount of posteroanterior displacement at L5/S1 and the location of the lowest instrumented vertebra. With a reduction of free motion segments, listhesis increased into posterior direction. Taking the tilt correction into account led to considerably increased values of disc height whereas displacement was affected only to a minor degree.

CONCLUSIONS

Long segment spinal fusion in young patients with idiopathic scoliosis did not lead to disc space narrowing during 9.2 years follow-up. However, the observed increase in retrolisthesis potentially indicates the initiation of a degenerative process. These only minimal changes might be referred to the preservation of a physiologic lumbar lordosis. Without correction for vertebral tilt disc space narrowing is overestimated.

Operative Therapie der idiopathischen Skoliose mittels ventraler Doppelstabinstrumentation

BACKGROUND

In the surgical treatment of idiopathic scoliosis both anterior and posterior correction and instrumentation techniques are available. The aim of the present study was to analyse the results of a new anterior dual rod instrumentation.

PATIENTS AND METHODS

Prospective analysis of radiometric and clinical parameters of 93 patients operated on between 1996 and 2004 using the Münster Anterior Dual Rod System.

RESULTS

The average curve correction was 65% (fusion length usually Cobb levels) with a preoperative Cobb angle of 59 degrees. Postoperative loss of correction amounted to 1.5 degrees (average follow-up of 36 months). Apical vertebral derotation averaged 45% in the thoracic and 53% in the lumbar spine with a subsequent correction of the rib hump of 66% and the lumbar hump of 81%. There were no revisions or neurological complications.

CONCLUSION

Anterior dual rod instrumentation enables an effective and safe three-dimensional curve correction in single structural curves with only minimal loss of correction.

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.

Lumbale Spinalkanalstenose

Lumbal spinal stenosis is gaining more and more clinical relevance because of changing population structure and increasing demand on lifequality in the elderly. Current treatment recommendations are based on clinical experience, expert opinions and single studies rather than on proven evidence. The radiologic degree of stenosis does not correlate with the patients' clinical situation. It is not the main factor indicating surgery but rather the typical history and spinal claudication. Symptomatic patients with light to moderate complaints should undergo multimodal conservative treatment. Epidural injections, delordosating physiotherapy and medication are useful. In patients with severe symptomatic stenosis surgery is indicated after a conservative treatment of 3 months. Relevant pareses or a cauda equina syndrome are absolute indications for surgery. The general aim is to decompress sufficiently while maintaining or restoring segmental stability. A laminectomy is not necessarily required. In patients with accompanying degenerative Meyerding grade I-II spondylolisthesis or instability in functional radiographs, fusion or dynamic stabilisation are recommended in addition to decompression, depending on the patient's age and activity level.

Post-discectomy syndrome treated with lumbar interbody fusion

We studied 27 patients with post-discectomy syndrome. All patients had Lumbar Interbody Fusion with titanium cages and pedicle screw fixation either as Anterior (ALIF, n=18) or as Transforaminal Lumbar Interbody Fusion (TLIF, n=9). Follow-up ranged from 24 to 94 months. The clinical and radiological data were compared. The outcome was evaluated using the Oswestry low back pain disability score and the visual analogue pain intensity scale. Outcomes were similar for all patients regardless of surgical technique and showed a significant improvement at final follow-up.

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 degrees to 10.9 degrees) in the digital radiometric rotation analysis, surface derotation amounted to 49% (range from 9.6 degrees to 4.9 degrees) in the rasterstereography, and to 70% in the clinical scoliometer measurement (range from 8.0 degrees to 2.4 degrees ). In group 2, there was an increase of rotation of the noninstrumented secondary thoracic curves by 30% (range from 5.0 degrees to 6.5 degrees ) in digital radiometry, by 32.9% in the rasterstereography (range from 8.5 degrees to 11.3 degrees), and a 28.3% increase in scoliometer measurement (range from 6.0 degrees to 7.7 degrees).

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.

Rasterstereographic analysis of axial back surface rotation in standing versus forward bending posture in idiopathic scoliosis

The forward bending test according to Adams and rib hump quantification by scoliometer are common clinical examination techniques in idiopathic scoliosis, although precise data about the change of axial surface rotation in forward bending posture are not available. In a pilot study the influence of leg length inequalities on the back shape of five normal subjects was clarified. Then 91 patients with idiopathic scoliosis with Cobb-angles between 20 degrees and 82 degrees were examined by rasterstereography, a 3D back surface analysis system. The axial back surface rotation in standing posture was compared with that in forward bending posture and additionally with a scoliometer measurement in forward bending posture. The changes of back shape in forward bending posture were correlated with the Cobb-angle, the level of the apex of the scoliotic primary curve and the age of the patient. Averaged over all patients, the back surface rotation amplitude increased from 23.1 degrees in standing to 26.3 degrees in forward bending posture. The standard deviation of this difference was high (6.1 degrees ). The correlation of back surface rotation amplitude in standing with that in forward bending posture was poor (R (2)=0.41) as was the correlation of back surface rotation in standing posture with the scoliometer in forward bending posture measured rotation (R (2)=0.35). No significant correlation could be found between the change of back shape in forward bending and the degree of deformity (R (2)=0.07), likewise no correlation with the height of the apex of the scoliosis (R (2)=0.005) and the age of the patient (R (2)=0.001). Before forward bending test leg length inequalities have to be compensated accurately. Compared to the standing posture, forward bending changes back surface rotation. However, this change varies greatly between patients, and is independent of the type and degree of scoliosis. Furthermore remarkable differences were found between scoliometer measurement of the rib hump and rasterstereographic measurement of the vertebral rotation. Therefore the forward bending test and the identification of idiopathic scoliosis rotation by scoliometer can be markedly different compared to rasterstereographic surface measurement in the standing posture.

Empfehlungen zur Sportausübung bei Patienten mit idiopathischer Skoliose

The idiopathic scoliosis is a three dimensional spinal deformity mostly occurring in female adolescents. Untreated it can progress and result in back pain, impaired lung capacity and psychosocial disorders due to the cosmetic appearance of the deformed trunk. The treatment depends on the severity of the curve and ranges from physiotherapy and observation, brace treatment to surgical treatment with partial correction and fusion of the primary curve. Patients with an idiopathic scoliosis should be encouraged to actively take part in sports activities. Positive influences on the general fitness including the lung function, on the trunk muscles and on the psyche can be expected. There are no scientific data indicating that any kind of sport activities alter the natural history of idiopathic scoliosis.

Effectiveness of hydroxyapatite-vancomycin bone cement in the treatment of Staphylococcus aureus induced chronic osteomyelitis

In the field of local application of antimicrobials, a number of novel drugs and/or new drug delivery systems have been developed in recent years. The present study aimed to investigate hydroxyapatite cement (HAC) as a carrier for vancomycin in the treatment of chronic osteomyelitis due to Staphylococcus aureus strains with various mechanisms of resistance. The release of vancomycin from standard test cylinders was determined in vitro and the efficacy of the delivery system was measured in vivo using a rabbit model of chronic osteomyelitis. First, powdered HAC was mixed with vancomycin at 80, 160 and 240 mg/g. After hardening, formed cylinders were eluted in phosphate buffer and antibiotic release was measured by agar diffusion. High levels of release (1512+/-318 to 1937+/-336 microg/ml) were obtained for 12 to 20 days depending on the dosage of vancomycin. Additionally, bone infection was induced in the tibia of 30 New Zealand white rabbits by injecting either a methicillin-resistant S. aureus strain (MRSA) or a S. aureus strain with a small colony variant (SCV) phenotype. After 3 weeks (chronic infection), all animals were treated by debridement. Moreover, group 1 (challenged with SCVs) and group 2 (challenged with MRSA) were treated by filling the marrow with HAC alone, whereas in groups 3 (SCVs) and 4 (MRSA) the marrow was filled with HAC/vancomycin (160 mg/g). After 6 weeks all animals were sacrificed. At 3 weeks, pathogens were detected in 24 of 30 animals. All swabs of the control groups, positive for S. aureus on day 21, were also positive on day 42 and S. aureus strains recovered were shown to be clonal to the strains used for induction of osteomyelitis. By contrast, no growth was found in the treatment group following 7 days of incubation in BHI bouillon. HAC/vancomycin-treated animals showed no histological evidence of infection on day 42. In the other groups, different stages of chronic osteomyelitis were found histologically. No local or systemic side effects due to HAC or vancomycin were seen. HAC is an effective carrier material for antibiotic compounds even in refractory infections due to MRSA or S. aureus SCVs.

Lumbale Bandscheibenprothesen

Lumbar interbody fusion used to be the most common surgical treatment for painful lumbar disc degeneration. With the technical development of total disc prostheses, replacement of the degenerated disc by a motion preserving implant has become a widely discussed alternative. The advantages of such replacement appear to include the prevention of adjacent segment disease as well as less perioperative morbidity. Three types of total disc prostheses are currently in common use. Although numerous studies have been made, a review of the literature reveals only two multicenter randomized studies comparing the outcome of disc prostheses with a control group of fusion patients. After 2 years, the available results show similar improvement after both types of surgery without significant differences. However, there is a trend towards faster recovery and improvement in disc arthroplasty patients. The long-term results of current and future randomized studies, including studies comparing results after disc arthroplasty, with results of standardized conservative therapies will determine the fate of lumbar disc prostheses.

[Surgical therapy of unspecific and specific Spondylodiscitis]

AIM

The aim of this study was to evaluate the clinical and radiological results of surgical treatment of thoracic and lumbar vertebral osteomyelitis by means of one-stage extrafocal posterior stabilisation, anterior debridement, and anterior column reconstruction.

METHOD

A retrospective analysis of the peri- and postoperative parameters of 62 patients with a clinical and radiographic follow-up of 2.6 years that were available for 46 patients was performed. In 42 cases, the anterior column was restored with structural bone grafts, in 20 patients, expandable titanium cages filled with morsellised autologous bone and antibiotic collagen sponges were used. To assess the course of spinal alignment a radiometric analysis was undertaken. Furthermore, the Roland-Morris score (RMS) was applied to evaluate the back pain-related disability.

RESULTS

The diagnosis was made no earlier than 2.7 months after the first symptoms. Preoperatively, 40 % of the patients presented with neurological impairment, of these 76 % improved after surgery. Staphylococcus aureus was the most common pathogen isolated (32 %), Mycobacterium tuberculosis was found in 11 % of the patients. Except for one patient with revision for persistent infection and consecutive failure of the bone graft, primary eradication of the infection was achieved in all cases. At follow-up, bony fusion was radiographically observed in all patients. When using cages, the segmental loss of correction was significantly lower than when using bone grafts (1.0 vs. 4.1 degrees ). At follow-up the RMS averaged 6.6.

CONCLUSION

One-stage extrafocal posterior stabilisation combined with anterior debridement and anterior column reconstruction with bone grafts or titanium cages is a safe and effective strategy for patients with vertebral osteomyelitis in need of surgery. Titanium cages have proven to be biomechanically advantageous, especially in cases of extensive destruction and are not associated with higher rates of persistence or recurrence of infection compared to autologous bone grafts.

Transforaminal lumbar interbody fusion: a safe technique with satisfactory three to five year results

The unilateral transforaminal approach for lumbar interbody fusion as an alternative to the anterior (ALIF) and traditional posterior lumbar interbody fusion (PLIF) combined with pedicle screw instrumentation is gaining in popularity. At present, a prospective study using a standardized tool for outcome measurement after the transforaminal lumber interbody fusion (TLIF) with a follow-up of at least 3 years is not available in the current literature, although there have been reports on specific complications and cost efficiency. Therefore, a study of TLIF was undertaken. Fifty-two consecutive patients with a minimum follow-up of 3 years were included, with the mean follow-up being 46 months (36--64). The indications were 22 isthmic spondylolistheses and 30 degenerative disorders of the lumbar spine. Thirty-nine cases were one-level, 11 cases were two-level, and two cases were three-level fusions. The pain and disability status was prospectively evaluated by the Oswestry disability index (ODI) and a visual analog scale (VAS). The status of bony fusion was evaluated by an independent radiologist using anterior-posterior and lateral radiographs. The operation time averaged 173 min for one-level and 238 min for multiple-level fusions. Average blood loss was 485 ml for one-level and 560 ml for multiple-level fusions. There were four serious complications registered: a deep infection, a persistent radiculopathy, a symptomatic contralateral disc herniation and a pseudarthrosis with loosening of the implants. Overall, the pain relief in the VAS and the reduction of the ODI was significant (P<0.05) at follow-up. The fusion rate was 89%. At the latest follow-up, significant differences of the ODI were neither found between isthmic spondylolistheses and degenerative diseases, nor between one- and multiple-level fusions. In conclusion, the TLIF technique has comparable results to other interbody fusions, such as the PLIF and ALIF techniques. The potential advantages of the TLIF technique include avoidance of the anterior approach and reduction of the approach related posterior trauma to the spinal canal.

[The natural history of congenital defects and deformities of the spine (I)]

The functional assessment of individuals with congenital defects of the spine requires a differentiated judgement. A lumbalisation or sacralisation of the lumbosacral junction does not seem to be associated with increased lower back pain. However, it remains unclear whether this is the case in individuals with a spina bifida occulta. Defects of segmentation or formation alter the biomechanical loading of the spine, especially in cases of a secondary spinal deformity the functional status can be substantially impaired. Spinal deformities include idiopathic scoliosis, Scheuermanns kyphosis and spondylolisthesis. Depending on the severity of the deformity, they can affect the functional status and may be associated with increased lower back pain.

[Prospective evaluation of braces as treatment in idiopathic scoliosis]

AIM

To prospectively evaluate the results of brace treatment in idiopathic scoliosis and to define risk factors of treatment failure.

METHOD

Fifty-two patients with a Cobb angle of between 25 and 40 degrees were included in the study. Prior to initiation of brace treatment with the Chêneau-Toulouse-Muenster orthesis, skeletal age and flexibility of the curve (bending films) were evaluated. The average follow-up after weaning of the brace was 42 months (36-78 months).

RESULTS

An average initial Cobb angle of 31 degrees was corrected to 18 degrees (43 %) under brace treatment with a flexibility to 6 degrees Cobb angle on bending films. Three years after weaning there was an overall increase of the Cobb angle to 37 degrees on average. The apical vertebral rotation was corrected from 16 degrees to 11 degrees (31 %) and increased to 20 degrees during follow-up. Thoracic kyphosis changed from 24 degrees to 18 degrees during treatment. At the latest follow-up kyphosis had returned to the pre-treatment angle again. Twenty-two patients had a curve progression during or after brace treatment of more than 5 degrees. In 14 patients surgical correction and fusion have been indicated. There was a positive correlation between flexibility and Cobb angle correction during brace treatment and a negative correlation between Cobb angle correction during brace treatment and curve progression (p < 0.05).

CONCLUSIONS

Curve progression was prevented in 58 %. Prognostic risk factors are a young age at initiation of brace treatment, a thoracic curve, unsatisfactory curve correction in the brace and a male gender.

Results after anterior-posterior lumbar spinal fusion: 2-5 years follow-up

Between 1991 and 1998, we treated 72 patients with fusion of the lumbar spine using posterior pedicle screw fixation followed by anterior retroperitoneal insertion of a titanium cage filled with autogenous bone graft. All patients had chronic low back pain after failed conservative treatment. We were able to review 54 patients with a mean follow-up of 51 (24-97) months. The mean Oswestry low back pain disability score improved from 56.8 preoperative to postoperative 29.8 and 31.2 at follow-up (p<0.05). The mean visual analog pain intensity scale improved from 8.3 to 4.0 postoperative and 4.8 at follow-up (p<0.05). The results demonstrate that circumferential lumbar fusion can be an option for the treatment of chronic low back pain.

Transient hemiplegia in posterior instrumentation of scoliosis

STUDY DESIGN

A case of transient hemiplegia during posterior correction and instrumentation of scoliosis in an 18-year-old woman.

OBJECTIVE

To present a case of transient hemiplegia most probably resulting from an arteriovenous fistula.

SUMMARY OF BACKGROUND DATA

Neurologic impairment in spinal surgery is a feared complication. Common reasons are direct or indirect trauma to neural elements, intraoperative hypotension, ischemia, bleeding, metabolic dysbalances, or drug effects. Review of the literature did not reveal any case of transient hemiplegia similar to the presented one in which none of the mentioned pathologies could be found.

CASE SUMMARY

An 18-year-old woman with a right long thoracic lordoscoliosis measuring 67 degrees Cobb angle and a marfanoid phenotype underwent posterior correction and transpedicular instrumentation from T3 to L2. After uneventful correction of the deformity through rod rotation, the wake-up test revealed a right-sided hemiplegia without facial asymmetry or other neurologic abnormalities affecting structures above the spinal cord. The rods were removed, the pedicle screws left in place, and the patient was turned on her back. Within 30 minutes after extubation, the neurologic deficits disappeared completely. Extensive diagnostic workup, including magnetic resonance angiography, did not show any pathologic findings explaining the transient hemiplegia. Two weeks later, the surgical correction was completed. After rod rotation again, right-sided hemiplegia was found in the wake-up test. Leaving the correction and after finalizing surgery, the patient was turned on her back and a 5 x 3-cm mass became apparent in her right sternocleidomastoid region. Color-coded duplex sonography revealed an arteriovenous fistula between the right external carotid artery and the right internal jugular vein. After extubation, the mass disappeared and within minutes all neurologic functions returned to normal again.

CONCLUSIONS

Spine surgeons should be aware of arteriovenous malformations as a potential cause of neurologic disturbances.

Titanium cages in the surgical treatment of severe vertebral osteomyelitis

The role of spinal implants in the presence of infection is critically discussed. In this study 20 patients with destructive vertebral osteomyelitis were surgically treated with one-stage posterior instrumentation and fusion and anterior debridement, decompression and anterior column reconstruction using an expandable titanium cage filled with morsellised autologous bone graft. The patients' records and radiographs were retrospectively analysed and follow-up clinical and radiographic data obtained. At a mean follow-up of 23 months (range 12-56 months) all cages were radiographically fused and all infections eradicated. There were no cases of cage dislocation, migration or subsidence. Local kyphosis was corrected from 9.2 degrees (range -20 degrees to 64 degrees ) by 9.4 degrees to -0.2 degrees (range -32 degrees to 40 degrees ) postoperatively and lost 0.9 degrees during follow-up. All five patients with preoperative neurological deficits improved to Frankel score D or E. Patient-perceived disability caused by back pain averaged 7.9 (range 0-22) in the Roland-Morris score at follow-up. In cases of vertebral osteomyelitis with severe anterior column destruction the use of titanium cages in combination with posterior instrumentation is effective and safe and offers a good alternative to structural bone grafts. Further follow-up is necessary to confirm these early results.

Rasterstereographic back shape analysis in idiopathic scoliosis after posterior correction and fusion

OBJECTIVE

To determine the accuracy of rasterstereographic three-dimensional back surface analysis and reconstruction of the spine in idiopathic scoliosis treated by posterior correction and fusion.

DESIGN

Prospective imaging study of 25 patients with idiopathic scoliosis who underwent posterior correction and fusion and were followed for one year.

BACKGROUND

In an earlier study published in this journal rasterstereography has proved to be an accurate imaging modality for quantifying the changes in the three-dimensional shape of the spine and posterior rib cage after anterior correction and fusion. Goal of the present study was to determine the accuracy for the more common posterior correction and fusion with attention paid to the presence of the posterior implants and scarring.

METHODS

Twenty-five patients with idiopathic scoliosis with maximum Cobb angles of 78 degrees were examined by rasterstereography and radiography. Seventy-one anterior-posterior radiographs were digitised. Twenty-four were preoperative and 47 postoperative radiographs. Rasterstereographic and radiographic curves were compared by best-fit superimposition. Root-mean-square differences were calculated as parameters of accuracy.

RESULTS

The accuracy of rasterstereography in severe idiopathic scoliosis with Cobb angles between 48 degrees and 78 degrees was satisfactory with root-mean-square differences of 5.8 mm for the lateral deviation and 4.8 degrees for vertebral rotation. Following posterior correction the accuracy was good. The root-mean-square difference was 4.5 mm for the lateral deviation and 4.3 degrees for vertebral rotation.

CONCLUSION

The accuracy obtained for posteriorly-operated scolioses between 50 degrees and 80 degrees was similar to the findings for scolioses operated via anterior approach, as well as those with curves up to 50 degrees Cobb angle. Therefore rasterstereography can be used postoperatively to reduce the number of radiographs and radiation exposure. Additionally, the method provides an objective quantification of the postoperative improvement in the cosmesis of the back shape.

RELEVANCE

In the treatment of severe idiopathic scoliosis rasterstereography provides both a considerable reduction of X-rays and an objective documentation of the cosmesis before after scoliosis surgery.

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 degrees to 92 degrees 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 degrees to 2 degrees after surgery and to 8 degrees 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.

Three-level en bloc spondylectomy for desmoplastic fibroma of the thoracic spine: a case report

STUDY DESIGN

A case of desmoplastic fibroma of the thoracic spine treated by a three-level en bloc spondylectomy is reported.

OBJECTIVES

To present a rare case of desmoplastic fibroma of the spine, and to emphasize the importance of at least a marginal resection of this tumor entity.

SUMMARY OF BACKGROUND DATA

Desmoplastic fibroma is a rare tumor, with the literature reporting approximately 220 cases of the disorder in patients younger than 30 years of age. This disorder has a predilection for the mandible and the meta-diaphyses of long bones. A location of desmoplastic fibroma in the spine has been reported in only a few cases. Desmoplastic fibroma has a high tendency of local recurrence, especially after intralesional resection.

METHODS

The reported case is that of a 14-year-old girl with a desmoplastic fibroma of the 9th, 10th, and 11th vertebrae. After confirmation of the diagnosis by CT-guided biopsy, a three-level en bloc spondylectomy with marginal resection of the desmoplastic fibroma was performed from the posterior approach. Stabilization was achieved with a multilevel pedicle screw instrumentation, and an autologous fibula was used for reconstruction.

RESULTS

At this writing, 31 months after surgery, the girl has no evidence of recurrence and is pain free.

CONCLUSIONS

Wide resection of tumors located in the spine actually is impossible to achieve because of the anatomic relations to the spinal cord, the major vessels, and the lung. As in the current case, a marginal resection is the maximal one to be achieved. Three of seven cases (43%) of desmoplastic fibroma in the spine treated by intralesional resection resulted in a local recurrence. These data clarify the importance of at least marginal resection of desmoplastic fibroma, if this is anatomically and technically possible. A local recurrence of desmoplastic fibroma in the spine can be impossible to treat surgically with a curative intention without a significant loss of function.

Complications of halo treatment for cervical spine injuries in patients with ankylosing spondylitis--report of three cases

BACKGROUND

Patients suffering from ankylosing spondylitis are prone to injuries of the cervical spine even with minor trauma. Although the fractures are markedly unstable, nonsurgical treatment using a halo-thoracic plaster or jacket is a common approach.

METHODS

We present three patients with cervicothoracic fractures of the ankylosed spine to describe problems and complications inherent in this type of treatment. In two, pin track infections and pin protrusion through the skull occurred, leading in one case to an intracerebral hemorrhage. In the third patient, the halo had to be removed after 8 months, just early enough to prevent the pins from cutting through.

RESULTS

One patient required craniotomy. The second one could be resolved by local revision. In the third case, the fracture eventually united after using a stiff collar for 2 years.

CONCLUSION

Halo treatment for cervical spine fracture in patients with ankylosing spondylitis is a challenging task for orthopedic surgeons and neurosurgeons.

Neurohistological examination of the inferior glenohumeral ligament of the shoulder

The neural histology of the anterior band of the inferior glenohumeral ligament (IGHL) was studied in 11 fresh shoulder specimen using a special silver impregnation technique. Between the collagen fibers small myelinated and unmyelinated dendrites could be detected. The appearance of neurovascular structures in the adjacent synovial layer clearly exceeded the typical supply to soft tissues. Analysing about 11,000 sections Ruffini mechanoreceptors that are known to be slow adapting were found on the humeral insertion of the band. The sections containing these neural end organs were identified by means of transillumination and reflection-contrast microscopy and reconstructed using three-dimensional image processing. The presence of neural structures including Ruffini corpuscles in these most important passive stabilizers of the shoulder joint shows that these ligaments function also as an active safety device. There slow adaption is a prerequisite for muscular reflexes counteracting the tensile stresses to which the passive stabilizing structures of the shoulder are exposed. A disruption of the continuity of these structures by mechanical forces or surgery can reduce the biofeedback and proprioceptive quality and thus lead to a decrease of shoulder function and/or stability. These observations should be taken into account when planning surgical interventions involving the IGHL. Procedures like capsule shifts or plications may affect mechanoreceptor orientation and concentrations, thereby affecting the interaction between these structures and the synergistic muscles. When possible, these intervention should avoid receptor-dense regions while attempting to restore normal anatomical orientation and tissue tension.

Rasterstereographic back shape analysis in idiopathic scoliosis after anterior correction and fusion

OBJECTIVE

To determine the accuracy of rasterstereographic three-dimensional back surface analysis and reconstruction of the spine in cases of severe idiopathic scoliosis treated by anterior correction and fusion.

DESIGN

Comparison of digitized radiographic curves and rasterstereographic curves by best fit superimposition and calculation of root mean square differences as parameters of similarity.

BACKGROUND

Rasterstereography has been proven to be accurate in scoliosis up to 50 degrees Cobb angle. Since 1989 the device is in clinical routine use for non-operatively treated patients and reduces the need for otherwise indispensable radiographs significantly.

METHODS

Fifty two patients with severe idiopathic scoliosis with Cobb angles up to 88 degrees were examined rasterstereographically and radiographically. Forty eight pre-operative anterior-posterior radiographs and 101 post-operative anterior-posterior radiographs were digitized. Radiographic and rasterstereographic curves were compared and the root mean square differences were calculated as parameters of precision of rasterstereographic reconstruction.

RESULTS

Accuracy of rasterstereography in idiopathic scoliosis with Cobb angles between 50 degrees and 88 degrees is satisfactory. The root mean square difference of the radiographic and rasterstereographic curves was 6.4 mm for lateral deviation and 4.5 degrees for vertebral rotation. After anterior scoliosis surgery the precision of the device is good. The root mean square difference for lateral deviation was 3.4 mm and 3.2 degrees for rotation. Considering both groups an average root mean square of 4.7 mm and 3.7 degrees was calculated.

CONCLUSIONS

Accuracy in severe scoliosis up to 88 degrees Cobb angle was satisfactory. The results of this first evaluation of surgically treated severe scoliosis showed a good accuracy after anterior surgery. The system can be used for post-operative follow up examinations and may reduce the number of X-rays considerably. In contrast to radiography, CT or MRI rasterstereography provides an objective quantification and documentation of the post-operative cosmetic improvement of the back shape in standing posture. RELEVANCE STATEMENT: Based on the findings of this study rasterstereography in future enables both objective quantification of cosmetic improvement and significant reduction of X-rays in idiopathic scoliosis with Cobb angles higher than 50 degrees before and after anterior surgical correction and fusion.

[Selective ventral derotation spondylodesis in idiopathic thoracic scoliosis: a prospective study]

AIM

Radiometric curve analysis of instrumented primary and spontaneous secondary curve correction after anterior correction and fusion of idiopathic thoracic scoliosis.

METHOD

Sixty-four patients with idiopathic thoracic scoliosis were prospectively evaluated. All patients were operated either with the Zielke-VDS or with a primary stable double rod instrumentation with selective fusion of the thoracic curve from end-to end-vertebra. Follow-up averaged 29 months (24 - 52 months).

RESULTS

The Cobb angle of the primary curve averaged 63.2 degrees preoperatively and was corrected to 21.4 degrees postoperatively with an average loss of correction of 5.3 degrees (58 % final curve correction). Apical thoracic vertebral rotation was corrected by 48 %. The secondary lumbar curve measured 38.2 degrees preoperatively (72 % correction on the bending films) and was spontaneously corrected by 57 % to 16.4 degrees without significant loss of correction in the final follow-up. Apical vertebral rotation averaged 11.3 degrees in the lumbar curve and was corrected spontaneously by 24 % to 8.6 degrees without significant loss of correction. Lumbar apex vertebra deviation showed no significant reduction. There was no case of lumbar curve decompensation in either frontal or sagittal plane. Implant related complications were observed in 7 patients (rod breakage), but no pseudarthrosis occurred. There were no neurological complications noted.

CONCLUSION

Selective anterior correction and fusion in idiopathic thoracic scoliosis enables a satisfactory correction of both primary and lumbar secondary curves. The advantage of selective anterior correction and fusion of thoracic scoliosis is the short fusion length, better derotation and satisfactory correction of the secondary lumbar curve. The disadvantages of single threaded rod techniques in terms of lack of primary stability and a kyphogenic effect have been eliminated by the development of a primary stable, small size double rod instrumentation.