Obtaining Patient-Reported Outcomes Electronically With "OncoFunction" in Head and Neck Cancer Patients During Aftercare

The disease and treatment of patients with head and neck cancer can lead to multiple late and long-term sequelae. Especially pain, psychosocial problems, and voice issues can have a high impact on patients' health-related quality of life. The aim was to show the feasibility of implementing an electronic Patient-Reported Outcome Measure (PROM) in patients with head and neck cancer (HNC). Driven by our department's intention to assess Patient-Reported Outcomes (PRO) based on the International Classification of Functioning during tumor aftercare, the program "OncoFunction" has been implemented and continuously refined in everyday practice. The new version of "OncoFunction" was evaluated by 20 head and neck surgeons and radiation oncologists in an interview. From 7/2013 until 7/2017, 846 patients completed the PROM during 2,833 of 3,610 total visits (78.5%). The latest software version implemented newly developed add-ins and increased the already high approval ratings in the evaluation as the number of errors and the time required decreased (6 vs. 0 errors, 1.35 vs. 0.95 min; p<0.01). Notably, patients had different requests using PRO in homecare use. An additional examination shows that only 59% of HNC patients use the world wide web. Using OncoFunction for online-recording and interpretation of PROM improved data acquisition in daily HNC patients' follow-up. An accessory timeline grants access to former consultations and their visualization supported and simplified structured examinations. This provides an easy-to-use representation of the patient's functional outcome supporting comprehensive aftercare, considering all aspects of the patient's life.

[Automatic calculation and visualization of comorbidity scores for decision-making in tumor boards]

OBJECTIVE

Comorbidity reduces treatment options for patients with head and neck cancer (HNC). Utilization of ICD-10 codes instead of manual research may facilitate estimation of comorbidity relevant for decision-making in the interdisciplinary tumor board (TB). Providing this information immediately in an intuitively ascertainable way whenever registering a patient for the TB would trigger awareness for comorbidities and shows potentially missing information.

MATERIAL AND METHODS

Administrative data was extracted of four databases at our clinic (hospital information system (HIS*-MED), the clinic's tumor database, OncoFlow^® and OncoFunction^®). After data extraction and record linkage facilitated by python libraries Pandas and Record linkage, ICD-10 codes were rated applying the Charlson Score and prepared for visualization within OncoFlow^®. Coding quality was tested assessing the imported and manually researched diabetes status of a 1:1 matched cohort of 240 patients.

RESULTS

29 073 ICD-10 codes of 2087 HNC patients were extracted. Matched data are immediately made available whenever registering a patient for the TB and are visualized in a pictogram within OncoFlow^® providing information about comorbidities and missing diagnostics. The precision of diagnostic coding at our clinic was 95.0 %.

CONCLUSIONS

The high prevalence of comorbidities in HNC patients with impact on their eligibility for particular treatment indicates the usefulness of our algorithm for providing automatic comorbidity assessment from administrative data for clinical routine and requires high quality of coding diagnoses.

Finite element model of the proximal femur under consideration of the hip centralizing forces of the iliotibial tract

BACKGROUND

the aim of our investigations was the development of a finite element model of the hip joint under consideration of the hip centralizing forces of the iliotibial tract within different femoral neck angles and its influence to the centralizing of the femoral head to the acetabulum.

METHODS

for the development of the finite element model of the femur and the iliotibial tract we utilized the program IDEAS 3D as well as the material/lengthening characteristics of the iliotibial tract. In the following step we developed a hip joint model with different centrum-collum-diaphysis-angles of 115°, 128° and 155° for determination of the IT force and the consequential force on the femoral head.

FINDINGS

with a coxa vara the force on the femoral head in relation to the physiological centrum-collum-diaphysis-angle and the coxa valga decreased (115°=1601N, 128°=2360N, and 155°=2422N). On the other side the hip centralizing forces of the iliotibial tract within a coxa vara increased in comparison to 128° (physiological) and 155° (valga) (115°=997N, 128°=655,5N, and 155°=438N). Within a coxa valga a higher compressive force on the femoral head and with a coxa vara a decreasing compressive force on the femoral head occurred.

INTERPRETATION

the clinical relevance consists in the predictability of an increasing or decreasing band wiring effect of the iliotibial tract in reliance to the centrum-collum-diaphysis-angle of the femoral neck and its importance for the displacement osteotomy of the growing hip.

[Influence of disc prosthesis position on segmental motion in the lumbar spine]

AIM OF THE STUDY

Total disc arthroplasty is reported to maintain segmental motion. From finite element studies a rather posterior and central implantation of the prosthesis is recommended. However, there is yet no in vitro study with cadaveric specimens investigating the topic of implant positioning.

METHODS

Ten human lumbar spines were subjected to biomechanical testing. Flexion/extension and side-bending moments were applied from 2.5-7.5 Nm on a spine load simulator. First, the intact specimens were tested in 3 load cycles while motion was monitored with regard to the facet joints under different loads by an ultrasound-based system. An unconstrained total disc prosthesis was then implanted in a central position and the different load cycles were repeated. Finally the implant was positioned in a decentral position with an average offset of 6.2 mm for repetitive data acquisition.

RESULTS

Comparison of the facet joint motion in central and eccentric prosthesis positions resulted in the following averaged differences. During flexion of the lumbar spine an average difference of the reference point excursions of 0.38 mm was recorded on the ipsilateral facet joint with reference to the decentral position. For extension, the difference was 0.33 mm on average, for right side bending a difference of 0.63 mm was recorded while left side bending resulted in an average difference of 0.24 mm. The deviation of the reference markers on the contralateral facet joint showed the following average differences: for flexion 0.23 mm and for extension 0.54 mm, respectively. For side bending right/left the differences amounted to 0.18 mm and 0.39 mm. With regard to segmental motion there was no statistically significant difference for both the ipsilateral (p = 0.0564) and the contralateral (p = 0.2593) reference marker.

CONCLUSIONS

The comparison of the segmental motion after central and decentral implantation of a lumbar total disc prosthesis reveals differences that have, nevertheless, no statistical significance. However, for clinical use it is recommended to strive for a central position of the implant.

[Influence of inlay height on motion characteristics of lumbar segments in total disc replacement]

AIM OF THE STUDY

Maintaining segmental motion is one of the most reported theoretical advantages of total disc replacement (TDR). Several inlay sizes are available for reconstruction of the physiological disc height. The influence of the implant height on the range of motion (ROM) was investigated in a biomechanical study.

METHODS

A total of 10 human lumbar cadaver spines were subjected to biomechanical testing. Flexion/extension and side-bending moments were applied from 2.5-7.5 Nm on a spine load simulator allowing for all 6 degrees of freedom. Motion under different loads was monitored by the Zebris system in 3 dimensions. Initially intact specimens were tested in 3 load cycles. Then a total disc prothesis was implanted with an 8.5 mm inlay and the cycles were repeated. Finally in 5 cases a 1-mm larger inlay was inserted while in the remaining 5 cases the inlay was exchanged with a 2-mm larger implant. Neutral zone (NZ) and ROM were recorded under the different loads.

RESULTS

The average motion for the various loads showed no significant difference when the intact motion segment was compared to the specimen containing the 8.5-mm inlay. After the larger inlay had been mounted the average reduction of the ROM in flexion/extension was 25% under the load of 7.5 Nm, 26% under a torque of 5.0 Nm and 30% when 2.5 Nm were applied. The NZ was reduced by 37%. For side-bending the ROM was reduced by 21% under a load of 7.5 Nm, by 26% under 5.0 Nm and by 35% under a torque of 2.5 Nm. The NZ was decreased by 27%. The reduction of the ROM was significant (p=0.0057).

CONCLUSION

Segmental lumbar motion is maintained after TDR. The size of the inlay can significantly change the ROM in lumbar spine segments treated by TDR.

Anatomical and biomechanical investigations of the iliotibial tract

Divergent descriptions of the anatomic location and biomechanical function of the iliotibial tract (IT) can be found in the literature. This study attempted to obtain exact data regarding the anatomic course and material characteristics including the biomechanical properties of this structure. The following were its aims: (1) anatomical investigations of the IT; (2) mechanical properties of the IT; (3) femoral head centralizing force of the IT and subligamentous forces in the height of the greater trochanter in different joint positions by using a custom-made measuring prosthesis and a subligamentous positioned sensor; (4) construction of a finite element model of the proximal femur including the IT and measuring the femoral neck angle under variation. The hip joints and IT in a total of 18 unfixed corpses were evaluated. We studied the anatomic relationship to surrounding structures, as well as the material properties with the help of tensile strength testing utilizing an uniaxial apparatus. During the test, a load-displacement curve was registered, documenting the maximum load and deformation of the IT. To measure the subligamentous pressure at the height of the greater trochanter, a custom-made sensor with a power-recording instrument was constructed. Furthermore, an altered hip prosthesis with a pressure gauge at the height of the femoral neck was used to measure the forces which are directed at the acetabulum. The investigations were done in neutral-0 position and ab/adduction of the hip joint of the unfixed corpse. In addition, we varied the femoral neck angle between 115 degrees and 155 degrees in 5 degrees steps. To confirm the subligamentous forces, we did the same measurements intraoperatively at the height of the greater trochanter before and after hip joint replacement in 12 patients. We constructed a finite element model of the proximal femur and considering the IT. The acquisition of the data was done at physiological (128 degrees), varus (115 degrees), and valgus (155 degrees) femoral neck angles. The influencing forces of the IT at the height of the greater trochanter and the forces at the femoral head or the acetabulum could be measured. Our anatomical investigations revealed a splitting of the IT into a superficial and a deep portion, which covers the tensor fasciae latae. The tensor fasciae latae has an insertion on the IT. The IT continues down the femur, passing over the greater trochanter without developing an actual fixation to the bone. Part of the insertion of the gluteus maximus radiates into the IT. The IT passes over the vastus lateralis and inserts at the infracondylar tubercle of the tibia or Gerdy's tubercle, at the head of the fibula, as well as at the lateral intermuscular septum. Portions also insert on the transverse and longitudinal retinaculum of the patella. Concerning the material properties of the IT, we found a structural stiffness of 17 N/mm extension on average (D = 17 N/mm). The subligamentous measurements at the height of the greater trochanter in the unfixed corpse and intraoperatively during hip joint replacement showed an increase of the forces during adduction and a decrease during abduction of the hip joint. We found thereby a maximum increase up to 106 N with 40 degrees adduction. Concerning the femoral neck angle, we can state that valgus leads to lower subligamentous forces and varus to higher subligamentous forces. The forces directed at the acetabulum, which were measured by the prosthesis with a sensor along the femoral neck, showed a decrease with varus angles and an increase with valgus angles. The highest force of 624 N was measured with 40 degrees adduction and an angle of 155 degrees. The finite element model of the proximal femur showed a sole hip joint-centralizing force of the IT of 655 N with a femoral neck angle of 128 degrees after subtraction of the gluteal muscle force and the body weight. At 115 degrees, we found an increase up to 997 N and a decrease to 438 N at 155 degrees. Concerning the resulting forces in the acetabulum, we found opposite forces in comparison with the force of the IT at the height of the greater trochanter: at 115 degrees, a femoral head-centralizing force of 1601 N; at 128 degrees, 2360 N; and at 155 degrees, 2422 N. By our investigations, we can approximately prove the hip joint-centralizing force of the IT. By variation of the femoral neck angle and the position of the hip joint, we can predict the subligamentous force of the IT and the resulting force at the femoral head or at the acetabulum. The intraoperative measurement of the subligamentous forces of the IT is a good monitoring mechanism for the persistent hip-centralizing function of the IT in the course of hip joint replacement. The surgeon has the opportunity to check the stability of the hip joint after replacement. The finite element model gives the opportunity to check the divergent relative strength by variation of the femoral neck angle and the tension of the IT. In this way, the changes in the forces induced by a displacement osteotomy could be estimated preoperatively.

Korrelation von lumbogenem Schmerz und vermehrter Vaskularisation in den Wirbelkörperendplatten

AIM OF THE STUDY

Degenerative changes of the motion segments are accompanied by an increased vascularization of the endplates. Nerve elements have been demonstrated in the environment of the endplate vessels, which might play a role in pressure related pain sensation. In order to investigate this theory we compared and correlated the extent of memory pain as determined by discography with the amount of vascularization in the endplates on histological examination.

METHOD

Discography was performed in 32 Patients (21 female, 11 male), who underwent spinal fusion. The extent of pain sensation was determined on a self reported visual analogue scale ranging from 0-10 Points. Bone chips from the anterior vertebral endplates were obtained during surgery. Decalcified paraffin-embedded samples were then immunostained with the vascular endothelial marker CD 34. The quantification of endothelium as part of the whole cross section area was performed by means of a computerized optical method.

RESULTS

The extent of the pain sensation during discography ranged from 0-9 points on the VAS (average: 5.3 points, SD 3.1). On the histological quantification the total endothelial area per observed field varied from 0.04 to 7.39 % (average: 2.19 %, SD 1.62). The comparison of the pain extent on discography and the vascularization of the endplate resulted in a correlation coefficient after Spearman of rho = + 0.64 (p=0.0006).

CONCLUSION

The extent of vascularization in the degenerated endplates of a motion segment shows a moderate correlation with the self reported VAS scores after discography. Further investigations will have to clarify, whether neurogenic structures originating from vascular endothelium yield a better correlation to discogenic pain.

[Kyphoplasty - a new minimally invasive treatment for repositioning and stabilising vertebral bodies]

AIM OF THE STUDY

Osteoporotic vertebral fractures are an ailment of the aging population of increasing incidence and high socioeconomic impact. Intractable pain causing significant morbidity leads to long-term hospitalisation. Kyphoplasty offers a new minimal invasive operative stabilisation procedure for these vertebral compression fractures. This study is conducted to investigate whether this procedure significantly reduces both pain and the duration of hospital stay in comparison to conservative treatment modalities.

METHOD

From January until July 2002 a total of 22 patients had undergone kyphoplasty in 37 vertebral bodies. Osteoporotic vertebral fractures were treated in 18 cases, while in another 4 cases prophylactic stabilisation for osteolytic lesions was performed. Both the duration of hospital stay and the reduction of pain symptoms were determined and compared to a conservatively treated control group of 20 patients suffering from 35 fractured vertebral bodies. Pre- and postoperative endplate angles were measured to assess the restoration of the sagittal alignment. The effects on pain symptoms were measured on a self-reported Visual Analogue Score Scale.

RESULTS

The mean pain relief for the patients undergoing kyphoplasty was 82 %, which was significantly higher (p < 0.0001) compared to the group of the conservatively treated patients (42 %). Reduction of the kyphotic deformity was achieved in 4 cases (average 8.5 degrees ). The average in-patient treatment duration for the surgical treated patients was 10 days as opposed to a significantly longer mean hospitalisation of 20 days (p = 0.003). Cement extravasation was observed in 5 out of 37 treated vertebral bodies without clinical sequelae.

CONCLUSION

Kyphoplasty is a safe minimal invasive procedure for the stabilisation of osteoporotic vertebral fractures leading to a statistically significant reduction both of pain status and duration of hospitalisation.

[Biomechanical design of load simulation in multiple spinal segments]

Multisegmental biomechanical studies on the lumbar spine are steadily increasing in importance. Only in this way can we acquire knowledge about the physiological behaviour of the entire lumbar spine. Furthermore, these studies allow us to analyse in vitro the biomechanics of manipulated lumbar spines after various surgical operations on the spine. A load simulator was developed to investigate multisegmental lumbar spine mobility, and its function was investigated in an initial study on 19 fresh--frozen specimens of human lumbar spine. After x-ray examination and determination of the bone mineral density, the specimens were loaded up to 10 Nm in the automatic electromechanical loading system under flexion/extension, lateral bending and axial rotation. An ultrasound-based motion analysis system was used to measure the displacements of the vertebrae involved.

[Comparative analysis of lumbar spine degeneration documented by x-rays versus large specimen cryomicrotome sections]

AIM OF THE STUDY

The extent of degenerative changes in the lumbar spine as seen on conventional radiographs is interpreted on the basis of visualized osseus structures and indirect signs such as diminution of disc height. In order to analyze the accuracy of these interpretations we compared and correlated different stages of degeneration in conventional radiographs with cuts of large-specimen cryomicrotome sections (LSCS), offering a direct macroscopic vision of the degenerative anatomic features.

METHOD

A total of 50 human cadaver lumbar spines with 251 spine segments (Th 12 - S1) was investigated by plain radiograms and LSCS. The degenerative changes were differentiated into 5 stages for both diagnostic measures. Criteria for radiological degeneration were: diminution of disc space, presence of osteophytes and sclerosis of the endplates. Degenerative changes as seen by LSCS were evaluated by the following features: cracks in the endplate, bleeding into the intervertebral disc, alignment of the annulus fibrosus fibres and osseous alterations in the spine segment.

RESULTS

Complete matches of the evaluated radiological and macroscopic stages of degeneration were observed in 206 cases. A difference of 1 degree on the degeneration scale was registered in 42 segments, whereas a difference of 2 degrees was seen in 3 cases. The correlation coefficient between the degeneration stages of the two diagnostic measures scored rho = 0.883.

CONCLUSION

The comparison of the different degrees of degeneration in the lumbar spine as evaluated by both plain radiographs and LSCS revealed a good correlation.

Prognostic significance of the Nasca classification for the long-term course of congenital scoliosis

AIM

The aim of our investigations was to answer the question of whether the radiologic classification according to the investigations of Nasca has prognostic relevance for congenital scoliosis. Based on our results, a therapeutic concept was given.

PATIENTS AND METHODS

Radiographs of 49 patients with a congenital scoliosis were classified according to Nasca. The progression of the malformation was analyzed by regarding the changes over a period of 8.3 years on average.

RESULTS

Of the analyzed patients with congenital scoliosis, 73% showed a mean progression rate of 1.8 degrees per year. The most advanced progress of the Cobb angle per year was seen in patients with unilateral unsegmented bars with or without additional hemivertebrae (type 4 according to the Nasca classification) and patients with wedge-formed vertebrae (type 2a according to the Nasca classification). The presence of unilateral bars and the location of the hemivertebra or hemivertebrae (type 4) and wedge-formed vertebrae (type 2a) are the major determinants of deformity. Within the scope of our investigations, the following three factors were seen as deleterious when combined: thoracolumbal and long-distance scoliosis, female gender, and prepubertal growth period.

CONCLUSION

From our analysis of 49 patients, we can propose the following therapeutic system for congenital scoliosis. Sole treatment with physiotherapy should only be recommended with congenital scoliosis curves ranging from 0 degrees to 20 degrees according to the Cobb method. With a Cobb angle smaller than 40 degrees and some flexibility remaining in the spine, the congenital scoliosis should be treated additionally with corrective casts. For congenital scoliosis with a Cobb angle of more than 50 degrees, as well as for congenital scoliosis with a poor prognosis (for example unilateral bars), a spondylodesis of the spine should be done before reaching the age of 5 years.

Use of extracorporeal shock-wave therapy (ESWT) in the treatment of non-unions. A review of the literature

Presently, extracorporeal shock-wave therapy (ESWT) is not yet a standard therapeutic technique in orthopaedics. The mechanism for the analgesic effect or the effect of shock waves on osseous defects are still unknown. With the help of a review of the literature, indications and success rates for ESWT in the treatment of non-unions are outlined, while adequate impulse and energy rates are defined according to the present state of knowledge. Non-union is defined as an absent healing process after a duration of 6 months. The aim of this study is to rate the published data. A total of 52 papers referring to ESWT of the locomotor system are reviewed, with a focus on the 635 patients from 10 publications who underwent ESWT to treat non-unions. Validation was performed for each paper dealing with this topic according to the internationally accepted system of the American Association of Spine Surgery as types A-E. Conclusions regarding possible applications in therapy were taken only from high-quality publications of types A and B. This advice can be regarded as scientifically as well as economically sound. The investigations concerning non-union hardly live up to scientific standards. No serious complications were observed. Because of the complication rate in operative treatment of non-unions, ESWT seems to be justifiable. The techniques of ESWT, energy density levels and impulse rates will be described. Atrophic non-unions seem to represent a poorer starting point in comparison with hypertrophic non-unions. Most investigations showed a consolidation of the non-union during a period of 3 months following ESWT, so that in case of treatment failure, operative treatment in the form of a re-osteosynthesis would only be delayed for this period of time. The advantages of ESWT are its non-invasiveness and low rate of complications. The primary aim of further research should be the evaluation of adequate energy density levels and impulse rates for various indications in accordance with evidence-based medicine. Long-term results need to become available before ESWT can be compared with established methods.

Material properties of trabecular bone structures

The transplantation of human allograft for restoration and filling of cortical bone defects is well known. Our aim was an experimental investigation of the mechanical stability of the often used femoral head spongiosa depending on the caliber and extent of the allograft. To evaluate the orientation of the trabecular structures of the femoral head and relate this data to its mechanical properties, morphometric studies were combined with mechanical tests of cancellous bone specimens. The mechanical examination of the allograft was done following the compression test according to DIN 50106. We examined 36 human unfixed hip joint spongiosa cylinders with a height of 11 mm and a diameter of 24 mm. We took three specimens from each femoral head. We compressed the allograft at a constant velocity of 0.017 mm/sec. We calculated the maximum compression strength, the yield point and the Young's modulus. We also examined 12 parallelepipedic specimens with (17 x 17 x 51 mm) for morphometric analysis and loading in the direction of the primary compressive group (PCG), as well as perpendicular loading and at an angle of 45 degrees. We found divergent mechanical stabilities. None of the femoral heads showed comparable compressive strength. There was no position dependency of the strength of the samples. No relation between optical appearance and strength was found. We found a value for the lower compressive strength, which can be used for calculation as a basic value for safe constructions. Furthermore we tested the well known dependence of strength on the direction of the trabecular structure. We found a strong relationship between strength and load direction on the preferred direction of the trabecular structure. The sole recommendation resulting from our investigations is to rely on the lowest compressive strength for all preoperative planning. Relying on higher compressive strength by using the theoretical predicted areas of higher strength is hazardous since we found no correlation between position of sampling and strength. The size of our samples is important, because of the fact that different sizes of the samples might cause different failure mechanisms in the samples. The preparation of the femoral head spongiosa should be done according to the primary compressive group of the trabecular structure.

cis element/transcription factor analysis (cis/TF): a method for discovering transcription factor/cis element relationships

We report a simple new algorithm, cis/TF, that uses genomewide expression data and the full genomic sequence to match transcription factors to their binding sites. Most previous computational methods discovered binding sites by clustering genes having similar expression patterns and then identifying over-represented subsequences in the promoter regions of those genes. By contrast, cis/TF asserts that B is a likely binding site of a transcription factor T if the expression pattern of T is correlated to the composite expression patterns of all genes containing B, even when those genes are not mutually correlated. Thus, our method focuses on binding sites rather than genes. The algorithm has successfully identified experimentally-supported transcription factor binding relationships in tests on several data sets from Saccharomyces cerevisiae.

Correction of kyphotic deformity before and after transection of the anterior longitudinal ligament--a cadaver study

With a custom-made measuring unit, two separate experiments, involving six and five cadaveric torsos with intact rib cages and sternums, respectively, were carried out to determine the effect of the transection of the anterior longitudinal ligament with and without osteodiscectomy and its influence on the thoracic kyphosis. The open or thoracoscopically assisted anterior release, as part of the operative treatment of scoliosis or kyphosis, usually consists of a transection of the anterior longitudinal ligament (ALL) and an additional discectomy. A complete osteodiscectomy, however, is not always possible with a minimally invasive approach. As part of our biomechanical research, we attempted to quantify the amount of correction achievable with a defined force prior to and following the isolated transection of the anterior longitudinal ligament. The aim of the study was to clarify whether or not an isolated transection of the anterior longitudinal ligament is sufficient to obtain an adequate anterior release of the spine. In the surgical treatment of kyphotic deformities, anterior release of the spine is performed in the form of a transection of the ALL and discectomy. Recently, video-assisted thoracic surgery has become increasingly popular in spine surgery. As part of this change in surgical technique, the question has arisen as to what extent an isolated transection of the ALL provides an adequate release of the thoracic spine. Eleven human spines were retrieved from fresh cadavers, dissected, and attached to a specially constructed apparatus. The spine was attached to the construct at the twelfth vertebral body. C6 and C7 were fixed in synthetic resin. We installed the instruments in such a manner as to reproducibly apply a torsional moment of 10 Nm to the spine. Motion was only permitted in the sagittal plane. Segmental transections of the ALL were carried out from T3 to T7. For comparison, the sagittal Cobb angle was also documented following an anterior release combined with an osteodiscectomy. With the isolated transection of the ALL, an average correction of the sagittal Cobb angle of 4 degrees in each functional spinal motion segment was recorded. In comparison, the additional osteodiscectomy led to a further average increase of only 2 degrees per level. The measurements performed on human cadavers showed that the isolated transection of the ALL leads to a sufficient anterior release of the thoracic spine, allowing a correction of the kyphotic deformity. The release with a concomitant osteodiscectomy represents a more time-consuming and more invasive procedure resulting in only a slightly greater amelioration of the sagittal Cobb angle, while being associated with a greater patient morbidity.

[Degenerative changes of the lumbosacral transition after Risser and Harrington spondylodesis]

INTRODUCTION

The long-term results of two operation techniques according to Risser and Harrington were of special interest. As part of this study, secondary changes of the lumbar spine, as well as the lumbosacral junction, were evaluated over time.

MATERIAL AND METHODS

Two groups of 20 patients, who underwent one of the above-mentioned operative procedures for idiopathic scoliosis were analyzed (group A: Risser procedure, average age 15 years; group B: Harrington procedure, 17 years of age). The preoperative deformity ranged between 34 degrees and 108 degrees Cobb angle. The patients were evaluated at three different points in time: 1) preoperatively; 2) upon the conclusion of outpatient treatment following the surgery; and 3) between 13 and 15 years postoperatively.

RESULTS

Degenerative changes, especially spondylarthrosis of the lumbosacral region, were seen more frequently in the Harrington group due to the higher rigidity of the implant and the ensuing increased loading of the adjacent spinal segments. The comparison of the two procedures revealed that a better primary correction of the deformity was achieved with the Harrington operation. Moreover, the Risser group showed a higher rate of pseudarthrosis and secondary loss of correction. In the Harrington group we found a higher rate of degenerative arthritis.

CLINICAL RELEVANCE

A better primary correction of the scoliosis leads to a higher strain of the lumbosacral junction. The resultant secondary changes (spondylarthrosis) in this period of observation were rarely of clinical relevance. Nevertheless, whenever possible presacral segments should remain free in the range of a spondylodesis to reduce the loading of the lumbosacral junction.

Complications of Chiari and Salter osteotomies: a cadaver study

Previous investigations of the Chiari and Salter osteotomies showed that intraoperative vessel and nerve injuries are described repeatedly in the case of both pelvic osteotomies. The aim of our investigations was the exposure of each operation step in anatomic specimens to show the anatomic landmarks and potential risks. We performed nine Chiari osteotomies and five Salter osteotomies on formalin-fixed cadavers. The operation steps were made consecutively to assess the risks to the vessels and nerves as well as the determination of anatomically important reference points. In both procedures an injury of the lateral femoral cutaneous nerve at the anterior access route is feasible. By ensuring that the skin including the lateral femoral cutaneous nerve is pulled medially, injury can be avoided. Additionally, too long retraction of the tensor fasciae latae muscle injures its nutrient vessels. An inadequate subperiosteal approach during the pull on the Hohmann's retractor leads to crushing and irritation of the sciatic nerve. Moreover, there is a risk that the superior gluteal nerve as well as the superior gluteal artery may be injured. An inadequate subperiosteal application of the medial Hohmann's retractor can endanger the obturator nerve. In the Chiari osteotomy there is a risk of injury to the articular branch of the superior gluteal nerve, which supplies parts of the ventral hip joint capsule. By inserting the K-wire too far medially the internal oblique muscle is endangered. Too prolonged retraction of the iliopsoas muscle in a Salter osteotomy can lead to compression of the femoral nerve. The form of the osteotomy has an influence on the stability of the hip joint in the course of exposure of the hip joint. On account of the narrow spatial connection between the anatomic pathways and the osteotomy area, strict subperiosteal dissection and careful use of the retractor are essential to avoid nerve and vessel injuries.

Thoracoscopically assisted ligamentous release of the thoracic spine: a cadaver study

The surgical treatment of thoracic kyphosis frequently requires an anterior release, which can be carried out by an open or endoscopic technique. This study concerns the reference points which are essential from the anatomic view for minimizing the operative risks. Furthermore we wanted to find the most convenient video-assisted thoracoscopic surgery (VATS) technique for transection of the anterior longitudinal ligament (ALL). Transection of the ALL, as well as discectomy, was performed using this technique. The extensive anatomic dissection of 12 fresh cadavers was performed to define possible technical errors and surgical complications. The development of new instruments has made the VATS approach to the ALL a viable alternative to open procedures. With the help of a standardized technique, the isolated thoracoscopic ligamentous transection required less time than the comparable open procedure. The anatomic study showed, that in no case was a ligation of the intercostal or segmental vessels necessary as part of the approach to the spine, once an adequate mobilization of the esophagus and azygos vein had been carried out. The risk of an ischemic lesion of the spinal cord was thereby reduced. The thoracoscopic, limited anterior release consisting of a multilevel transection of the ALL proved to be a rapid and reliable procedure. Our anatomic studies provides suitable the reference points.

Computer-assisted orthopedic surgery with individual templates and comparison to conventional operation method

STUDY DESIGN

Comparison was made of the accuracy of a pedicle bore performed by conventional technique and by using an individual template in the lumbar spine of cadavers.

OBJECTIVES

The fixation of pedicle screws necessitates a high amount of surgical skill and experience to avoid lesions of nerves and vessels. By using individual templates in a cadaver study the goal was to prove the accuracy and efficiency of this less-invasive image-guided surgery in comparison with the conventional technique by fluoroscopy and computed tomographic (CT) scan.

SUMMARY OF BACKGROUND DATA

Based on three-dimensional models generated from CT scans of the lumbar spine, precise preoperative planning of the position and trajectory of pedicle screws is possible. In comparison with other means of computer-assisted spine surgery with navigation systems, in which a time-consuming intraoperative matching of the bone surface structure is necessary, the use of individual templates enables the surgeon to reduce the operation time considerably.

METHODS

Individual templates are customized on the basis of three-dimensional reconstructions of the bone structures extracted from CT image data and depending on the individual preoperative surgical planning, which uses the desktop image processing system for orthopedic surgery (DISOS). A desktop-computer-controlled milling device is used as a three-dimensional printer to automatically mold the shape of small reference areas of the bone surface into the body of the template. Postoperative CT scans were obtained and the accuracy of the pedicle bore rated by two independent observers.

RESULTS

The preparation time with the individual template lasted slightly longer than with the conventional operation technique (555 seconds and 482 seconds, respectively). Fluoroscopic study took a mean time of 31.5 seconds, with the conventional operation technique and 5.5 seconds with the individual template. The assessment of the postoperative CT scans demonstrated a higher accuracy of the pedicle bore with the individual template.

CONCLUSIONS

This cadaveric study has shown that overall operation time including the fluoroscopy time can be shortened by using the individual template for the pedicle bore. The individual template is an alternative to the computer-assisted navigation systems with a good cost-performance ratio without excessive technical workload on the physicians or the surgical personnel. Further investigations must be conducted to validate the clinical applicability of this system.

Bilateral total hip replacement in pseudoachondroplasia

Pseudoachondroplasia is an inherited skeletal dysplasia with short-limbed dwarfism and early onset of osteoarthritis. A 29-year-old pseudoachondroplastic woman presented with progressively painful hips secondary to severe osteoarthritis of both joints, so that total joint replacements were necessary to restore her mobility and quality of life. The implants inserted had to be specifically manufactured in accordance with the individual geometry and reduced bone size. In addition, the implants mechanical resistance to dynamic loading conditions had to be tested prior to total hip replacement surgery.

[A smooth pneumatic motion device for dynamic MRI imaging of the cervical spine]

PURPOSE

To develop and evaluate a new, pneumatically operated motion apparatus for the dynamic functional MR examination of the cervical spine.

MATERIALS AND METHODS

A metal-free, pneumatically operated motion apparatus for functional dynamic MR imaging of the cervical spine was developed with respect to the geometry of a short-bore, superconducting high-field MR system. The examination protocol included a T2-weighted multi-slice turbospin echo sequence (T2-TSE, TR/TE = 2610/115, matrix 254/512) and a dynamic T2-weighted single-shot sequence (T2-TSE, TR/TE = 1110/110, matrix 255/256, acquisition time 1 s) in a sagittal plane. In order to evaluate the new motion apparatus and the examination protocol, 10 healthy subjects and 10 patients were examined.

RESULTS

The new motion apparatus allowed us to perform a passive stepless inclination and reclination motion of the patient's cervical spine within the MR scanner without leaving the magnet bore. The maximum motion degrees of the cervical spine were within -35 degrees (reclination) and 30 degrees (inclination). Due to the T2-contrast and the high spatial resolution of the dynamic sequence, the myelon, the surrounding cerebrospinal fluid and the discoligamental structures were imaged with a good contrast and allowed a sufficient evaluation of the cervical spinal channel in all functional positions.

CONCLUSIONS

This new motion apparatus allows a standardized and stepless dynamic functional MR examination in a short-bore high-field MR scanner. By the use of fast T2-weighted spin echo sequences it has been shown to be of high value for the evaluation of the cervical myelon, the anterior and posterior cerebrospinal fluid and the discoligamental structures.

Anatomy and function of the bursa subacromialis

The ligamentum coracohumerale, as the anterior limit of the bursa subacromialis, runs into the shoulder joint capsule, connecting--broadly based--above the sulcus intertubercularis. It does not, however, originate--as described previously--from the base of the processus coracoideus (viewed frontally), but rather medially from the base, i.e. on the side of the fossa supraspinatus. The sliding mechanism starting at 50 degrees affects the parietal sheet of the bursa subacromialis, whereby the laterally situated section slides under the medially situated section. With an abduction of up to 50 degrees, the lateral section congests in front of the corner of the acromion, sliding from there under the acromion, so that the--hitherto--medial section is located above the section now sliding away beneath it. This sliding mechanism continues on up to 100 degrees. At this point the parietal sheet of the bursa subacromialis lies as follows: The section that had been situated laterally at the beginning of the sliding mechanism now lies caudally to the section that had lain medially at the outset. The bursa subacromialis does not slide fully into the fossa supraspinatus, as in all of the cases observed, it is firmly connected, together with the fascia subdeltoidea, to the corner of the acromion. The visceral sheet does not change in the course of the sliding mechanism as described, as it is connected to the fascia of the supraspinatus muscle--with the exception of a medial stretch of 16 mm. A further finding deals with the course of the muscles of the caput breve of the biceps brachii. Individual muscle fibre components do not connect to the processus coracoideus, but rather run before the tip of the processus coracoideus into the ligamentum coracoacromiale, radiating not only into the ligamentum coracoacromiale, but also--certain components--into the shoulder joint capsule. Through this, the 'aponeurosis tendinis brachii' forms a tendon roof in front of the processus coracoideus that extends to the structures running along the head of the humerus. The muscle fibre components of the caput breve of the m. biceps brachii radiating into the shoulder joint capsule, together with the muscles of the rotator cuff and the ligamentum coracohumerale, keep the shoulder joint capsule tense, thus preventing constriction symptoms.

[Primary correction of scoliosis with the Wilmington corset]

QUESTION

As part of our study, the effectiveness and patient's acceptance of the Wilmington-brace is to be evaluated. The effectiveness can be documented with the help of the primary correction achieved, especially in light of the fact, that the primary correction and the long-term results are directly dependant upon one another.

MATERIAL AND METHOD

We examined a total of 52 patients with an idiopathic scoliosis treated in a thermoplast brace. The group consisted of 38 female and 14 male patients (average age 11.6 years). The angulation was measured with the help of the Cobb-angle and the rotation with the method described by Nash and Moe. The skeletal age was classified according to Risser's-sign. The angle determinations were carried out at three separate points in time--at first presentation, prior to bracing and four to six weeks following bracing.

RESULTS

The patients presented with an average angulation of 31 degrees. The average correction achieved in the Wilmington-brace was 41%. This corresponds to a correction of 13 degrees. The best primary correction (45%) was obtained in the thoracolumbar spine. Those patients with the smallest deformity at the onset of treatment showed the best results. The scoliosis with a large primary deformity and a marked rotation of the vertebral bodies responded poorly to correction. Advanced age or skeletal maturity were also limiting factors. Physical therapy had a positive influence on the amount of primary correction obtained.

CLINICAL RELEVANCE

The Wilmington-brace (thermoplast) allows for a good primary correction of idiopathic scoliosis. The simplicity of application and the low production costs are also positive attributes.

Anatomic and functional aspects of the kinetics of the shoulder joint capsule and the subacromial bursa

This anatomic study was devoted to the kinetics of the shoulder joint and especially the subacromial region. Following dissection of the shoulder joint capsule and subacromial region of 80 unpreserved shoulder joints, the anatomic relationships of the subacromial space in the neutral position and in continuous abduction (30 degrees, 60 degrees and 90 degrees with fixed scapulae) were examined. These investigations were supplemented by histologic preparations. In the course of our examinations we discovered a gliding mechanism of the subacromial bursa. Moreover, we found a subcoracoid attachment of the shoulder joint capsule and a precoracoid ligamentous connection running between the short head of the biceps brachii m. and the coracoacromial ligament. We termed this the coracoid aponeurosis, which facilitates gliding behaviour of the shoulder joint capsule beneath the coracoid process. In view of this gliding mechanism of the subacromial bursa and the coracoid aponeurosis, discovered in the course of our investigations, we have to reassess the kinetics of the sub-acromial and subcoracoid space. Further, we should reconsider our operative technique in cases of the subacromial or subcoracoid impingement syndrome.

Femoral nerve lesion in total hip replacement: an experimental study

A total of 20 hip joints of 10 non-fixed corpses were examined within 48 h of death to measure the pressure below the inguinal ligament simulating the surgical conditions during total hip arthroplasty. The purpose of this study was to assess the influence of various leg positions and insertion techniques of retractors during the surgical procedure for total hip replacement in order to detect supposed causes for indirect pressure injuries of the femoral nerve. The obtained results verified no increase of pressure in the inguinal canal which could explain an indirect injury of the femoral nerve. If the retractor is inserted correctly at the anterior acetabular rim, the pressure in the lacuna musculorum can even be reduced, and furthermore, the femoral nerve is protected by the iliopsoas muscle. Femoral nerve lesions which have been published so far can only be explained by an incorrect use of instruments or implants (e.g., screws, cement, acetabular cup) or an extreme postoperative leg length discrepancy.

The sensory innervation of the hip joint--an anatomical study

Typically obturator nerve blockade is used to relieve hip pain. It sometimes only has a minor effect in resolving symptoms. This clinical observation led us to examine comprehensively the sensory nerve innervation of formalin-fixed hip joint capsules. Following macroscopic preparation, the area of the hip joint capsule was inspected with the aid of an operating microscope. We discovered a separation between the anterior and posterior sensory innervation of the hip joint capsule. The anteromedial innervation was determined by the articular branches of the obturator n. Additionally, the anterior hip joint capsule was innervated by sensory articular branches from the femoral n. In the posterior part we found articular branches from the sciatic n., which in addition to the articular branches from the nerves to the quadratus femoris m., innervate the postero-medial section of the hip joint capsule. Moreover, articular branches of the superior gluteal n. were found, which innervate the posterolateral section of the hip joint capsule. This anatomical study demonstrates that the obturator n. block is insufficient for the treatment of hip pain. Further investigations will determine if these nn. can be reached percutaneously. Effective neural blockade of the hip joint must include the femoral n., the sciatic n. and the superior gluteal n.

[Problems in the admission to in-hospital oral surgical care from the patient's viewpoint--results of patient interviews in the hospital for dental and maxillo-facial surgery of the Karl Marx University, Leipzig]

The author deals with the results from the interviewing of oral surgery patients on their problems concerning the sending and the admission to the hospital, with special attention to the problems of waiting for admission, the familiarization with the clinical environment and the improvement suggestions of the patients. The conclusions concern tasks arising from the medical and dental care for inpatients as well as for outpatients.