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Purpose: The purpose of the presented study was to valuate the question whether subacromial denervation alone is sufficient in patients with subacromial pathology., Material and Methods: 20 patients (male: 7; female 13) with subacromial pathology without anterior acomionosteophytes, rotator cuff tear, calcific tendinitis or ac-joint pathology underwent endoscopically controlled subacromial denervation. The procedure was performed with an HF device. Patients were followed up at 6 weeks, 3 and 6 months with the Constant score., Results: The preoperative Constant score was 59 +/- 18. Postoperatively the Constant score increased to 78 +/- 18 after 6 weeks, up to 83 +/- 5 after 3 months and up to 85 +/- 13 after 6 months. There was no difference between male and female patients nor between patients with different profession or athletic activity. We could not document any complication. Patients returned to work within 6 weeks after surgery., Conclusion: Patients without anterior acromion osteophytes and without rotator cuff tear may get good results with subacromial denervation alone and may not need acrornioplasty.

Aim: Development of criteria for the medical-legal interpretation of different patterns of labral lesions according to the labrum pathology and mechanism of injury., Methods: A metaanalysis of the literature concerning injuries and diseases of the shoulder involving the glenoid labrum was performed., Results: Lesions of the superior, anterior and posterior labrum are rare and of different severity. Arthroscopically they are divided into distinct types. They develop either spontaneously together with intraarticular diseases, due to chronic fatigue or by injury. In this field the stability of the shoulder joint and the tension of the long head of the biceps tendon play an important role. There is no correlation between the type of lesion and mechanism of injury. With respect to medical-legal interpretation, the currently used classification of labral lesions is not very helpful or is even confusing. We therefore propose a new classification according to the meniscus pathology which shows a striking similarity to labral pathology. There are two types of labral lesions: Type one shows degenerative defects, which may be influenced by mechanical loading; type two follows from shoulder instability., Conclusions: Medical-legal interpretation of labral lesions should follow the same principles that were shown to be useful in knee joint instability and meniscal tears. Only traumatic luxations of the shoulder joint may lead to labral tears without any other alterations.

Purpose: The purpose of this study was to present and to evaluate different treatment options in the infected knee alloarthroplasty., Methods: We followed 47 infected knee alloarthroplasties with a mean follow-up of 62 months which were surgically treated by different techniques. There were 20 cases with early infection (< or = 12 months) and 27 cases with late infections (> 12 months)., Results: In 10 patients a two stage exchange of the implant were undertaken. In 6 of those 10 cases the infection could be successfully treated. 30 patients underwent an arthrodesis, two of those after an unsuccessful exchange procedure. In this group only in two patients the infection was not managed successfully. 28 of the patients with an arthrodesis showed a good result of the fusion side. One case was only debrided and in 8 cases bony and soft tissue damage lead to amputation. The HSS-score showed an excellent results in 5.3%, a good result in 21%, a fair result in 26.3% and a poor results in 47.4% of the cases. Comparable distribution was documented with the Hungerford-score. Patients with a stable and painless fusion showed a comparable functional outcome to those patients with a new replacement., Conclusion: Revision of an infected knee implant is best managed by a two stage procedure and can lead to a good functional result. Fusion is indicated in cases with bad bony and soft tissue situation. A solid arthrodesis gives a painfree and stable extremity.

Purpose: purpose of this study was to evaluate paediatric feet and to document possible problems., Material and Methods: In 345 high school pupils of the 5th and 6th class aged 10 to 13 the feet as well as leg alignment were evaluated with a standardised protocol., Results: Only 36.5% showed regular feet. In almost 2/3rd of the pupils malalignements or even deformities were present. The valgus foot showed the highest incidence with 39.4% followed by a flat foot with 19.1%. 17.1% of the children showed a hallux valgus. There was no correlation between body weight, body height, leg alignment and foot deformity. However, a significant correlation could we found between hallux valgus and splay foot., Conclusion: The presented data underlines the necessity for paying attention on the problems of the paediatric feet. During sport lessons in school a special foot training for children should be performed.

Purpose: The purpose of this study was to evaluate joint position sense (JPS) in patients with posttraumatic glenohumeral instability., Materials and Methods: In 28 patients with posttraumatic instability and in a matched control group of 30 subjects proprioception capability was evaluated. For documentation of proprioception an angle reproduction test (ART) was performed with which joint positions sense (JPS) was measured for abduction, flexion, and rotation in three angles each., Results: In both groups there was a significant better JPS with visual control than without. In contrast to the control group the patients were not able to increase angle reproduction capability without visual control when comparing positions below shoulder level with positions at or above shoulder level. When comparing the patients to the controls there were differences in most of the ARTs with worse results in the patient group. These differences were significant in 150 degrees flexion with and without visual control, in 150 degrees abduction without and in 100 degrees abduction with visual control. For rotation there were trends for almost all joint positions, however, the differences were significant only in the -45 position. When comparing the noninjured contralateral shoulder of the patients with the control group, there still were differences. Again these were not in all joint positions significant, but significant worse JPS could be demonstrated in 150 degrees abduction without visual control, 50 degrees flexion without visual control, -45 degrees rotation without and 0 degrees rotation with visual control., Conclusions: A proprioceptive deficit can be documented in patients with posttraumatic glenohumeral instability. This may be one reason for permanent instability. The contralateral joint also shows reduction in joint position sense. For consecutive treatment as well as for rehabilitation both shoulder joint should be addressed.

Background: To evaluate the level of documentation as an instrument of ongoing quality management in arthroplasty, a questionnaire was created on this subject, which concentrated on structural and process indicators., Methods: A total of 908 questionnaires was sent to orthopedic and trauma departments in Austria, Germany and Switzerland and were evaluated anonymously., Results: The quota of return was 54% in Switzerland, 47% in Austria and 25% in Germany. The waiting period for an arthroplasty is much less in Switzerland and in Germany than in Austria. Only 40% of patients receive forms for informed consent. Documentation is seldomly standardized thus making comparison virtually impossible. Surgical planning is usually done with templates in Germany and Austria, in Switzerland with drawings. Prosthesis passports are predominately used by orthopedic departments. The data regarding complication rates and infections are not analyzed at regular intervals (max. 30%) and corrective measures are rarely implemented., Conclusion: Documentation is the basic instrument of quality management and requires completeness (totality) and plausibility of the datas. It is of great importance that evaluated data are analyzed and consequences are taken. The primary aim of quality assurance is to identify problems that adversely affect quality in order to develop and implement process sequences for the improvement of patient care and management.

Aim of the Study: The series of this article compares 148 patients with chronic tendinitis (group I) and 28 patients with significant partial-thickness tears (group II) of the rotator cuff managed with arthroscopic debridement and acromioplasty., Methods: All patients were evaluated by an independent observer with a mean follow-up of 26.5 (12-51) respectively 23.4 (12-50) months using the Constant-score, the ASES-score and a visual analog scale. The mean age in group I was 48.5 (25.4-71) and in group II 56.1 (33.2-80.6) years., Results: In group I 127 patients (86%) and in group II 17 patients (62%) were satisfied at latest follow-up (p < 0.05). Concerning the exclusively subjective ASES-score with a maximum of 100 points group I had an average of 78.8 and group II of 61.6 points (p = 0.0019). According to the criteria of Constant group I scored with a mean of 81 points for the operated shoulder and 91.6 points for the non-operated side and group II with either 65.2 points and 89.9 points (p = 0.0036)., Clinical Relevance: Recognizing these results a thorough activity-related preoperative discussion with the patient about the treatment options for significant partial-thickness cuff ruptures should be performed.

Purpose: The purpose of this study was to present our long-term experience in elbow arthroscopy with special regard to diagnosis specific results., Methods: 103 out of 121 patients after elbow arthroscopy were evaluated with a mean followed-up time of 6.2 years. The age of the patients at time of surgery ranged between 3 and 72 years. For documentation the Figgie-Score was used. The results were documented in relation to the patients pathology., Results: The total score improved significantly from 49.3 to 89.3 (p < 0.05). There was no age dependency of the results, but a correlation to the preoperative duration of symptoms and the individual job situation. Between the different score parameters pain showed the highest improvement. While patients with free bodies as well as bacterial or rheumatic arthritis had a more noticeable gain, the postoperative improvement for the patients with severe degenerative arthritis was only limited. Patients with unclear preoperative problems showed no improvement at all., Conclusion: While patients with free joint bodies or synovitis without degenerative joint disease have a significant benefit from elbow arthroscopy, patient with severe degenerative joint disease or patients with restricted range of motion will hardly show any improvement after surgery.

Purpose of the Study: To compare the proprioceptive abilities of total knee arthroplasty patients and a control group., Method: In a knee arthroplasty patient group of 28 and in 25 healthy volunteers the proprioceptive function was examined. To measure the proprioceptive function the motion analysis system with reflecting markers was chosen. In each patient 16 measurements from different starting points in different joint positions with and without visual controlling were performed., Results: The results demonstrated significant differences between the patients and volunteers independent of the starting point, the joint position and the visual controlling. Also the comparison with the 30 and 60 degree position showed significant differences. In the patient group were not shown significant values comparing the starting position, the visual controlling and the comparison with the healthy leg., Clinical Relevance: Knee arthroplasty conducts to loss of proprioception in the operated and healthy leg. Visual controlling can not solve these problems. The worst results were achieved in 60 degrees position. The starting position can not influence the results.

Purpose: Aim of this study was to evaluate the results after athroscopic transglenoidal stabilization in patients with anterior posttraumatic shoulder instability., Methods: 30 patients with posttraumatic anterior shoulder instability were prospectively observed for a mean of 36 months (24-56) after an athroscopic stabilization has been performed. The operative technique was carried out as described by Morgan with use of transglenoidal sutures to repair the labrum., Results: All patients had a Bankart lesion and a Hill-Sachs defect. According to the criteria of Rowe, 24 patients (80%) had good or excellent results and 1 patient (3%) was graded as fair. 5 patients (17%) developed recurrent instability 6-24 months postoperatively so they had failed results. 83.4% had no or little limitation in sports activity. Sex, age or grade of activity had no influence on the result concerning stability. The mean preoperative dislocation rate was 8.6 for the failures and 5.9 for the stable results (p < 0.05)., Clinical Relevance: The results of arthroscopic stabilization of the shoulder are inferior to the classical open repair. It should only be performed in patients with unidirectional, posttraumatic anterior shoulder instability without capsulaligamentous hyperlaxity or multiple resdislocations.

Introduction: In spite of educational work for many years by the orthopaedic surgeons wrong lifting techniques are still used in everyday life as well as during exercise. The reason for this could be the fact that there is an advantage regarding these techniques from the energetic point of view., Material and Methods: To clarify this issue we examined 30 healthy males within the age range of 17 and 30 years (weight: 74.0 +/- 9.2 kg, height: 182.5 +/- 6.7 cm). In a randomised sequence the volunteers carried out two different lifting techniques: 1. Lifting with stretched legs and bent back, 2. Lifting with bent legs and stretched back (Brügger technique). The test scheme consisted of four different 3-minute exercise levels with increasing weights (0 kg, 5.2 kg, 12.1 kg, 19.2 kg), the repetition rate was 30 times per level., Results: Using the Brügger technique the results for heart rate, VO2, VCO2 and VE were highly significant (p < 0.001) above the results of the other technique at all exercise levels. On the RPE (rate of perceived exertion) scale the differences were statistically significant regarding the 0.01-level., Conclusion: The results give rise to the supposition that the energy consumption for the lifting technique with the bent back is lower and is therefore preferred in everyday life and during exercise. These findings should be taken into consideration when informing people about possible damages.

Purpose: The purpose of this study was to document and to present the acceptance of arthroscopically performed stabilising procedures of the glenohumeral joint., Method: In a nationwide survey of instructors of the association of arthroscopy, members of the arthroscopy group of the german orthopedic society, and orthopedic and trauma surgeons with special interest in joint surgery we evaluated the current treatment modalities for patients with unstable shoulder joints., Results: After an average of 2.09 +/- 1.0 shoulder redislocations surgery is recommended. The Bankart-operation (63.4%) is the favourite procedure for open surgery. In a descended order the Weber rotation-osteotomie, the Putti-Platt operation, the Max-Lange procedure, and in a minimal amount of the cases the Bristow-procedure are performed. Looking at the arthroscopic procedures, the distribution is much more equal. The Caspari technique is used by 27.6% and the Morgan technique by 25.1%. Bone anchors are used by 20.4% and the Suretac is used by 18.9% of the surgeons. The anchor knot technique (8%) is only rarely performed. In case of an elongated capsule the majority of the surgeons would not perform arthroscopic surgery. 42.4% of the surgeons judge the arthroscopic technique less secure. However, 38.9% do not see any difference to open procedures., Conclusion: Taking the available information, arthroscopic stabilising procedures seems to have slightly inferior results compared to standard open surgery. The Bankart procedure with or without a capsular shift is still the golden standard.

With the increasing use of pedicle screws in instrumented spine surgery the neurological risk must be evaluated critically. Studies, which evaluated the accuracy of pedicle screw placement in scoliosis surgery, have not been published up to date to our knowledge. In 25 consecutive patients with idiopathic scoliosis, who underwent posterior instrumented curve correction and stabilization, the accuracy of pedicle screw placement was evaluated using axial computed tomography. There was a total of 178 screws between T5 and L4. The preoperative Cobb angle of the curve averaged 60.7 degrees, the mean rotation of the instrumented vertebrae was 19.1 degrees according to Perdriolle. 145 pedicle screws (81.5%) were placed correctly within the pedicles, of which 4 screws (4.5%) penetrated the anterior aspect of the vertebral body with a mean of 0.9 mm. 22 screws (12.4%) showed lateral penetration of the pedicle with a mean of 1.9 mm, of which one screw was placed completely lateral of the pedicle. 8 screws (4.5%) penetrated the medial wall of the pedicle by 1.3 mm on average. One screw each penetrated the cranial and caudal border of the pedicle. Statistical analysis did not reveal any significant relationships between pedicle screw misplacement and grade of vertebral rotation or site of instrumentation. Neurological complications were not noted in any of the cases. In our mind the risk of pedicle screw threaded curve correction and fusion in scoliosis surgery in the hands of an experienced spine surgeon is calculated acceptably low.

Unlabelled: In 30 healthy volunteers (12 female, 18 male; age: 22-36 years) we evaluated the proprioceptive function of the glenohumeral joint. The volunteers were asked to place the arm in different positions with and without visual control. The test was performed for the dominant as well as for the non dominant extremity. The following joint positions were measured: 50 degrees, 100 degrees, 150 degrees abduction, 50 degrees, 100 degrees, 150 degrees flexion, +45 degrees, 0 degree, -45 degrees rotation in 90 degrees of abduction. The documentation of the joint position was performed with a motion analysing system with passive reflecting markers. The results showed significant differences between the measurements with and without visual control. Without visual control we found the worst results for flexion and extension below shoulder level. We documented significant differences of the results with and without visual control for this range of motion. However, for external rotation above the shoulder level we could not demonstrate significant differences. In neutral rotation as well as internal rotation we found again significant differences. Therefore, proprioception seems to be worse below the shoulder level (50 degrees abduction, flexion). Better results in comparison with the entire group had two volunteers with general good coordinative capabilities. We could not demonstrate differences between the dominant and non dominant extremity nor between male and female., Clinical Relevance: Our results demonstrated low variance of the proprioceptive function of the glenohumeral joint in healthy volunteers. This may serve as a base for further evaluations in different patient populations.

In 6.26% of 846 patients with lumbar disc surgery a reoperation was necessary. A total of 93 patient had undergone a revision surgery inclusive a patient group with primary surgery performed elsewhere. 68 patient had 1 reoperation, 22 patients 2, 2 patients 3, and one patient had even 4 revisions. Follow-up ranged between 19 and 42 years with an average of 31 years. 53 patients were clinically examined at a time of follow up and another 15 patients answered a questionnaire. An excellent result with no complaints and patients able to work could be achieved in only 16%. A good result with no radicular pain, but some minor back pain and some loss of sensibility and ability to work was found in 24%. In 40% of the patients the result was only fair with some radicular pain and limited capability for work. 20% of the patients had only a poor result with unchanged symptoms and continued therapy. Those patients were not able to work. Young and female patients had a better prognosis. Another positive predictor was a short period of preoperative pain. Negative predictors were multiple prior operation as well as scar tissue at time of revision. Also spondylodesis according to Cloward correlated also with a negative clinical outcome.

Based on results of anatomical studies, we established an arthroscopic procedure to resect all degenerative changes within the joint without endangering the stabilizing structures. Since November 1989 we operated on 26 patients with this technique. There were no major complications. The mean score significantly increased from 64.9 (+/- 12.8) to 86.8 (+/- 11.5). Analysis of postoperative x rays revealed an average length of resection of 21.3 mm at the inferior border of the clavicle, of 15.4 mm in the middle, and of 10.2 mm at the superior border of the clavicle. 21 out of 26 patients were completely satisfied and would undergo the same procedure again. In two of the five unsatisfied patients the resected length of the clavicle was insufficient and these patients required open surgery for resection of the remaining bone. Our first experiences are encouraging. The surgical technique is standardized and reproducible. The short time results score not worse compared to the open conventional technique. With the 2 to 4 year long term follow up we have to prove, whether maintaining the passive stabilizers of the joint improves the long term results better than the open technique.

Especially in idiopathic thoracolumbar scoliosis the approach and sort of instrumentation have controversially been discussed over the past years. Since 1986 32 patients with adolescent thoracolumbar scoliosis underwent operative treatment, 20 patients were treated with Cotrel-Dubousset Instrumentation (CDI), 10 patients underwent Ventral Derotation Spondylodesis (VDS). In 2 cases a combined two-stage VDS and CDI were performed. The follow-up was 38 months in the CDI-group and 19 months in the VDS-group. Length of the curve and the fusion were identical in the VDS-group. In the CDI-group, however, length of the fusion exceeded curve length by 4 segments on average. With CDI the fusion was carried down to L4 in most cases, in some cases to L5. Curve correction of the primary curve averaged 70% with VDS (preoperative mean 84 degrees) and 64% with CDI (preoperative mean 65 degrees). We observed a spontaneous correction of the secondary curve of 38% after VDS. With CDI the correction of the secondary curve averaged 42%, however, in secondary curves measuring more than 50 degrees primary and secondary curve were fused. A preoperatively physiological sagittal plane in the CDI-group remained unchanged after operative treatment. With VDS an average kyphosis of the thoracolumbar junction of +22 degrees was corrected to +7 degrees. We conclude that in the operative treatment of severe thoracolumbar scoliosis VDS offers significant advantages compared to CDI and should therefore be preferred. In moderate scoliotic deformities, where the number of caudally unfused segments is equal in both systems, CDI is justified.

Unlabelled: We harvested the joint capsule, the glenohumeral ligaments, and the coracohumeral ligaments of 8 fresh formalin-preserved shoulder specimen. We made use of the van Gieson technique and a special silver impregnation for staining peripheral axons according to Nowotny. The ligaments were cut into slices with a thickness of 15 microns. In total we performed 10,000 cuts. We discovered axons in all ligaments. These axons had no relation to vessels or vessel walls. Besides these axonal structures we detected type II mechanoreceptors (Pacini receptor)., Clinical Significance: The neural structures discovered in the glenohumeral capsule are of clinical importance especially in consideration of the high account of recurrent shoulder dislocation and concomitant Bankart lesions. Receptors located in the glenohumeral ligaments might control the stabilizing shoulder musculature. On this premises, rupture or detachment of these ligaments will lead to a loss of the feedback mechanism.

In a retrospective study we documented the need for blood transfusion in total knee (TKR) and hip replacement (THR). The problems with homologous blood transfusion in orthopedic surgery and alternative techniques of autologous-blood transfusions are discussed. In this series patients with primary THR needed 1.69 (+/- 2.25) blood units, with primary TKR 1.58 (+/- 1.54) blood units, and secondary TKR 1.19 (+/- 1.47) blood units, Secondary THR required significantly more units (3.85 +/- 3.07). These procedures also asked for significantly more plasma (3.27 +/- 3.95) than all other procedures. For secondary THR 2.63 (+/- 2.45) blood units were intraoperatively used and only 1.23 (+/- 1.09) blood units postoperatively. All other procedures needed postoperatively significant more units than intraoperatively. In secondary THR the use of blood transfusions increased with age. 45% of the patients with primary THR and 15% with secondary THR were operated without additional blood transfusion. In secondary THR 36% of all patients needed more than 4 blood units and 27% more than 4 plasma units. In TKR 39% of the primary cases and 50% of the secondary cases were operated on without additional homologous blood. Based on these results we established a transfusion concept for our department. Economic, practical, as well as legal aspects were taken into account.

Unlabelled: Several studies demonstrated the necessity of rehydration of lyophilized bone allografts prior to implantation. The purpose of the presented study was to evaluate the influence of different rehydration periods on the stability of human cortical lyophilized and gamma-irradiated allografts, the capability of lyophilized bone for rehydration, as well as the effects of lipid extraction on rehydration. Breaking strength of lyophilized irradiated cortical bone after different rehydration periods (0.5, 1, 2, 4, 8 hours) showed no significant difference. Weight reduction after lyophilization of human femoral heads was between 7.6% and 41%. Further weight reduction occurred after lipid extraction (38.7%). Total weight loss was 56.9%. There was a significant influence of intraosseous lipid content on the rehydration capability. After lyophilization alone the rehydration weight after 8 hours was only 18.1%, whereas after lipid extraction the weight increase was 43% after 0.5 hours, 36.4% after 1 hour, 57.6% after 2 hours, 60% after 4 hours, and 92.7% after 8 hours., Clinical Relevance: Based on the presented data rehydration time of 0.5 hours seems to have no disadvantage compared to longer time periods concerning breaking strength. Therefore a longer intraoperative time period seems not to be necessary. This is of advantage for a possible secondary contamination while the allograft is rehydrated. Rehydration after lipid extraction is more effective than rehydration after lyophilization alone. However, the question whether lipid extraction alter bone stability has to be proved in further studies.

In a cadaver dissection study the relation of the arthroscopic portals to the neurovascular structures was documented. In six cadaveric elbows the capsule was distended with 35-40cc fluid of 0.9% NaCl by using the direct lateral portal. An anterolateral and anteromedial approach to the elbow joint were established. The distance of the arthroscopic portals to the neurovascular bundles were measured at empty and filled joint after performing an anatomic dissection. The influence of flexion and extension of the joint as well as pronation and supination of the forearm on the distance of the arthroscopic sheath to the neural structures was documented. Lesions of the superficial cutaneous nerves were not seen. Using the anterolateral portal in the best position of the joint (90 degrees flexion and not distended joint at max. pronation of the forearm) we measured a proximity of 4.5 mm (range 2-10 mm) to the radial nerve. For the anteromedial approach the mean distance of the median nerve to the arthroscopic sheath was 15.5 mm (range 8-27 mm), when the optimal joint position was used (90 degrees flexed joint, distended, max. supination of the forearm).

6.5 years after lumbar chemonucleolysis (CNL) we examined 40 patients by MRI. All MRI studies were performed by a 1.0 tesla MRI. We documented the height of the discs, the chondrosis, the intradiscal MRI signal, as well as the intraosseous signal within the vertebral bodies (end plate reaction). Preoperative MRI studies (Tvor) and/or postoperative MRI studies within the first postoperative year (T1) of 18 patients were available. We found an overall reduction of the sagittal disc height of 26%. This reduction was 19% in the male patients and 45% in the female patients (p < 0.02). Comparing the T1-studies with the T6.5-studies, we could still reveal a proceeded reduction of 13%. In those patients who underwent three MRI studies, there was a reduction of 20% between Tvor and T1. Among one half of the patients we found a further decrease in disc height of 15% between T1 and T6.5, whereas the other half showed an increasing disc volume of 15%. At time of follow up (T6.5) all treated discs showed a reduced MRI signal (STIR) within the disc. The signal further decreased comparing the MRI signal (STIR) preoperatively with the follow up evaluation in 64.3% of the cases. However, we found an increase of the signal in 70% of the cases between T1 and T6.5. 6.5 years after CNL we documented an end plate reaction in almost 70% of all patients. There was no correlation between end plate reaction and age of the patients, level of CNL, amount of injected chymopapain or the clinical outcome.

For a biomechanical study 10 specimen of the lumbar spine (L1-S1) were scanned with MRI. After that 18 normal motion segments were prepared for the experiments. The paraspinal musculature as well as the posterior elements were removed. Under an axial load of 500 N, in each disc 500 J and 1000 J of energy were applicated with a Holmium-Yag laser (2060 nm, fiber thickness 600 microns) into the nucleus pulposus. In nine of the 18 discs also 1500 J and 2000 J were applicated. At the beginning of every standardized experiment of a motion segment, as well as after every 500 J, the height of the disc, intradiscal pressure, the contour of the disc and the size of the transversal plane of the disc were determined with an axial load on the motion segment of 1000 N. The change in radial bulging of the disc was measured using the computer-assisted recordings of each disc contour. All the data were statistically analyzed using the Friedman-/Wilcoxon-test. After every application of 500 J energy, in the 18 discs as well as in the 9 discs, the height and the intradiscal pressure reduced. The differences per 500 J were for all measurements not significant (p < 0.05). Up till the application of 1500 J the radial bulge and the size of the transversal plane of the disc increased, although the differences per 500 J were not significant. From 1500 J to 2000 J the radial bulge and size of transversal plane of the disc decreased.(ABSTRACT TRUNCATED AT 250 WORDS)

Unlabelled: In a vitro study we evaluated the influence of surgical technique on the postoperative tension of the supraspinatus tendon in rotator cuff ruptures. In ten shoulder specimens Hall-Effect Strain Gauge (HEST) were implanted in the supraspinatus tendon close to the insertion at the humerus. We documented the tension in specimens with intact rotator cuff as well as after reconstruction of small and large tears in different joint positions. In the specimens with an intact rotator cuff there was almost no tension registered. Only in adduction with external rotation and flexion we found slightly increased values. After reconstruction we found the highest tension in adduction, flexion, and external rotation of the humerus. Release of the coracohumeral ligament resulted in a decrease of tension in flexion and external rotation. Whereas in extension coracohumeral ligament release had no influence on the tension of the tendon. However, after complete capsule release the tension in extension also decreased., Clinical Relevance: If mobilisation in cases of rotator cuff reconstruction is necessary we recommend first release of the coracohumeral ligament in small and moderate tears. In major tears a complete capsule release is necessary. During physical therapy in the early postoperative course, flexion in the adducted and externally rotated arm should be avoided.

Unlabelled: 93 patients with a mean follow up of 73 months (30-133 months) after lumbar percutaneous radiofrequency denervation (PRFD) were evaluated. Mean age of the patients at time of surgery was 47 years (18-76 years). 54 patients had no lumbar spine surgery prior to facet denervation, 32 patients had one or multiple disc surgery prior to denervation, and 7 patients had spinal fusions. 51 patients were in the process of early retirement or already retired at time of surgery. Out of all 93 patients only 50% had significant pain relief immediately after PRFD. 3 months after PRFD the success rate dropped down to 38%. 6 years after surgery only 25% of all patients had long lasting good results. Patients who were pain free after facet infiltration had significant better initial results, but were similar to the others after 6 years. 6 out of 7 patients after lumbar spinal fusions demonstrated bad results. The worst results had those patients who had applied for early retirement (workmens compensation cases). In this group the recurrence rate was 74% 6 years after surgery. We found no correlation between the surgeon and the outcome., Clinical Relevance: Without pain reduction after facet infiltration the success rate after PRFD is low. Spinal surgery prior to PRFD significantly reduces the success rate. The worst prognosis have workmans compensation cases. The recurrence rate is high within the first 6 months after PRDF.

Unlabelled: In a prospective study we evaluated the benefits of iv-application of gadolinium-DPTA examining 25 patients with degenerative disease of the knee joint by MRI (1.0 Tesla). All patients were scanned with standard spin echo sequences (SE 500/20), short time inversion recovery sequences (STIR 1600/100), and FEDIF sequences (FEDIF 500/10). After gadolinium-DPTA application (0.1-0.35 mmol/kg BW) the patients were scanned with spin echo sequences (SE SE 500/20), and FEDIF sequences (FEDIF 500/10). After iv-Gadolinium the synovial membrane of joints with inflammation show significant increase of the signal. Due to this effect a differentiation between joint effusion and hypertrophic synovia is possible. Small areas of local synovitis not visible before the use of gadolinium can be documented. A differentiation between degenerative subchondral cysts and cysts due to an inflammatory process is possible., Clinical Relevance: The use of iv-application of gadolinium-DPTA in patients with degenerative joint disease seems to offer additional information. With iv-application all shortcomings of intraarticular use can be avoided. The differentiation between degenerative and inflammatory processes is possible.

In an experimental study with standardized conditions nuclear material of 40 human lumbar discs was excised. In 20 the non-automated discectomy method was used (NAPLD-method). In the other 20 the automated discectomy method (APLD-method). The excised material was weighted. After the removal, the material of the NAPLD-method was wet with isotonic saline over 45 minutes and again weighted. Afterwards the wet material of both methods was freeze dried and again weighted. The weight of the wet material of the NAPLD-method in relation to that of the freeze dried material was a factor 11 (average value: 7.7 g in relation to 0.7 g) and in the APLD-method a factor 15 (average value: 4.5 g in relation to 0.3 g). This means, that the uptake and distribution of the saline is different in both methods and for this reason it is not allowed to compare the wet weight of the two methods. This has to be considered in clinical comparative studies. Because the biomechanical changes after a discectomy are dependent of the amount of the excised nuclear material, the NAPLD- and APLD-method can only be compared when the amount of the excised material is changed in a freeze dried weight.

We evaluated the placement of pedicle screws (N = 131) in 30 patients after lumbar dorsal spinal fusion. Postoperatively all patients were examined by CT. 39.9% of all screws penetrated the cortex of the vertebra. Of special interest were those implants which led to medial penetration of the pedicle, which is of potential hazard to the neural structure within the nerve root canal. 28.5% of all screws showed a medial deviation. In our study, a penetration of more than 6 mm coincided with a high risk for nerve root damage. In 2 patients there was proven damage to a nerve root due to screw placement. In another 3 patients coherence was likely to exist. The technique of transpedicular screw fixation for spinal fusion is highly demanding and should be performed only by experienced surgeons after a clear indication and after a trial of intense conservative therapy.

For a biomechanical study 8 specimens of the lumbar spine (L1-S1) were scanned with MRI. After that 21 motion segments were prepared for the experiments. The paraspinal musculature as well as the posterior elements were removed. From each disc 1,0 g, 2,0 g, and 3,0 g of nuclear material were consecutively removed under an axial load of 500 N. At the beginning of every standardized experiment of a motion segment, as well as after the excision of every gram of nuclear material, intradiscal pressure, the height of the disc and the contour of the disc were determined with an axial load on the motion segment of 1000 N. The change in radial bulging of the disc was measured using the computer-assisted recordings of each disc contour. All the data were statistically analyzed using the Friedman-test. The nuclear material removed from the discs ('in-vitro nuclear material') was placed in isotonic saline over 45 minutes and again weighted ('wet weight'). Af that the nuclear material was freeze-dried ('dry weight'). The results of this study showed that after the excision of every gram of nuclear material the height of the disc decreased in average 0,77 mm. Also intradiscal pressure reduces significantly: from the initial stage, on average, 9, 19 bar to the endstage (= after the removal of 3,0 g), on average, 2, 58 bar. Radial bulge increases with every gram removed, on average 0,23 mm. The weight of the wet nuclear material is 2,6 times as much as that of the in-vitro nuclear material and 11 times as much as that of the freeze-dried material.

With a standardized questionnaire we evaluated 1450 orthopedic and general surgery departments. The response rate was 57.2%, 52% of the departments were using computers for different purposes. The favoured system was the MS-DOS system (73%). The computers were mainly used for word processing (58%), statistics (50%), and graphics (39%). For clinical routine the leading use was patient documentation (70%) followed by patient report generation (43%). Other applications (e.g. online use of administrative data (19.4%) or the use of other patient information like blood parameters (10%)) were relatively rarely used. However, most of the users have plans to incorporate these applications in the nearest future. For the out patients care the leading application is private billing (42.5%) and statistics (30%). The majority of the departments (42.6%) only have one PC. Most of the departments use the printer for hard copies and as hard disc a the standard storage medium. The average storage capacity of the used hard discs is 40 to 80 MB. Other peripheral tools like a laser printer, a scanner, or modems are rarely used. Most of the departments invested between 5000 and 15,000,--DM. 33.3% financed the computers only with the official budget of the department. However, 25.8% only used private funds to buy the hard- and software. The distribution according to zip codes showed a slight accommodation in Bavaria and NRW. The amount of new installations showed an almost constant increase from 1975 until 1981. Between 1981 and 1990 there was a significant increase with a small drop in 1986.

In 148 patients with impingement lesion type I or type II, we performed an arthroscopic subacromial decompression (ASD). 122 patients ran a follow up one to three years post-operatively. All patients were pre- and postoperatively documented by a 100 point shoulder score. The mean score was 57.9 (+/- 11.5) preoperatively. Postoperatively there was a significant increase to 80.7 (+/- 17.9) (p < 0.05). 15% of the patients with a postoperative score less than 70 points were determined as failures. Patients with a preoperative pain history of more than one year had a significantly worse result (79.1 +/- 8.4) compared to those patients with a preoperative course less than one year (88.8 +/- 11.6) (p < 0.05). Other significant factors were the patient's age, and calcific tendinitis, whereas sex, preoperative range of motion, muscle atrophy, and degeneration of the acromioclavicular joint did not significantly influence the result. Our results after ASD in patients with subacromial pathology without a rupture of the rotator cuff are encouraging. Therefore, ASD seems to be a reasonable alternative to open acromioplasty.

Luxation of the sternoclavicular joint is described on the basis of the case histories and progress of patients with this very rare form of injury who underwent surgical treatment on the Orthopedic Clinic of Düsseldorf University Hospital in the years 1978 to 1988. Four of the 6 patients in our study were subjected to a follow-up examination as out-patients. After preliminary remarks on the anatomical and biomechanical peculiarities of the sternoclavicular joint, the various types of luxation and the customary Allmann I-III classification for degree of severity are discussed. Surgical treatment is essential only for injuries of the IIIrd degree. Dislocation of the sternal end of the clavicle is most frequently found ventrad, as was also the case in all 6 patients in our study; the rarest finding is dorsad. The symptoms and the necessary diagnostic measures are described. Surgical treatment of the retrosternal luxation of the sternoclavicular joint is indicated as absolutely essential on account of the possibility of life-threatening complications. A relative indication of operative treatment exists for anterior luxation of the sternoclavicular joint where severe functional impairment and pain are present, e.g. during work and sport. The various operative methods currently in use are described. Reference is made to the importance of imaging techniques. A warning is given that, because of the risk of fatal complications, Kirschner wiring should not be used for retention of the reduction unless the K-wires are reliably secured.

In a biomechanical study we evaluated the stability of human femurs. In order to document the inter- and intraindividual differences in bending stability, and the changes in breaking strength after different storing and sterilizing procedures, we tested 200 bony blocks, which were harvested from the femurs of 5 multiorgan donors. The bending tests were performed with a material testing machine (ZWICK) under standardized conditions. The bone blocks we randomized into five different treatment groups (-25 degrees C deep freezing, steam sterilization, lyophilization, lyophilization + gamma irradiation, lyophilization + gamma-irradiation in argon). The statistical analysis was performed by a multivariant analysis. Our results revealed significant differences concerning breaking strength among different femurs of the 5 multiorgan donors, and a significant difference concerning stability in different areas of the same femur. Further on we found a significant difference with regard to the treatment modalities of the five groups. Compared to the control group (-25 degrees C deep freezing), we documented a decrease of 8.7% after steam sterilization, an increase of 18.9% after lyophilization, a decrease of 1.7% after lyophilization + gamma-irradiation, and an increase of 3.4% after lyophilization + gamma-irradiation in argon.

During the past various factors were quoted to be causative of a degeneration of the rotator cuff. In this study 122 shoulder specimen, aged 58-95 years, were dissected. A high correlation between severe degeneration of the ac-joint and rupture of the rotator cuff was found. The correlation was even higher between distally pointing osteophytes and cuff ruptures. The results demand to clearly define the degeneration of the ac-joint and the rotator cuff in patients suffering from shoulder pain. A simultaneous occurrence has to be considered. If conservative treatment fails in patients with cuff tear and ac-joint degeneration, surgical revision is recommended. This should comprise: 1. suture of the cuff-rupture 2. excision of the coraco-acromial ligament 3. anterior acromioplasty according to Neer 4. excision of the outer end of the clavicle

In a prospective study we evaluated the ap-translation of the humeral head in the glenoid socket during active joint movements. In 150 healthy volunteers we documented normative data for four different joint positions. We compared these results with the data of 36 patients with traumatic anterior shoulder instability. The normal joint in adducted position shows a dorsal overhang of the humeral head in relation to the dorsal brim of the glenoid of 8.9 mm (+/- 3.0) on the dominant and of 9.1 mm (+/- 3.1) on the non dominant side. In the 90 degrees flexion position the dorsal overhang was 7.6 mm (+/- 3.5) on the dominant and 8.0 mm (+/- 2.3) on the non dominant side. In neutral as well as in the flexion position we found no differences between men and women nor between the dominant and non dominant extremity. In 90 degrees abduction and neutral rotation, the dorsal overhang was 1.5 mm (+/- 3.5) on the dominant side and 1.9 mm (+/- 3.4) on the non dominant side in the volunteer group. However, in patients with shoulder instability we found a statistically highly significant difference with a ventral overhang of 3.0 mm (+/- 4.0) on the dominant side. On the non dominant side a dorsal overhang of 0.3 mm (+/- 3.7) still remained in the above mentioned position. The differences between both sides were statistically highly significant. In abduction and external rotation we found a similar relation with a highly significant larger anterior translation of the humeral head in patients with unstable shoulder joints.

Unlabelled: In a prospective study we evaluated the use of diagnostic ultrasound for Hill-Sachs lesions in unstable shoulder joints of 114 patients. In 38 patients we found a Hill-Sachs lesion by sonography. 31 patients underwent an arthroscopic procedure. The arthroscopic control of the sonographic findings showed a sensitivity of 95%, a specifity of 92%, an accuracy of 94%, a positive predictive value of 95%, and a negative predictive value of 92%. We also documented posttraumatic joint effusion. With these results ultrasound seems to be more reliable than x ray in the diagnosis of Hill-Sachs lesions., Clinical Relevance: With a high diagnostic value for detecting Hill-Sachs lesions ultrasound may replace difficult special x ray techniques.

Unlabelled: In a biomechanical study we evaluated the passive stabilizing ligaments of 9 fresh shoulder specimens with mercury bands. While preparing the specimens we found two interesting entities: there are fibers of the coracohumeral ligament running from the humeral head to the coracoacromial ligament and there was an reproducible thickening in the posterior joint capsule. Functional evaluation shows that the coracohumeral ligament limits external rotation independently of the amount of abduction as well as inferior subluxation. The mediale glenohumeral ligament shows the highest tension in external rotation and 30 degrees abduction. The anterior inferior ligament strengthens the joint capsule in abduction and external rotation. The posterior inferior ligament shows the highest tension in abduction and internal rotation., Clinical Relevance: Immobilization in internal rotation and adduction may lead to shortening of the coracohumeral ligament, which may result in severe limitation of external rotation and abduction. Resection of the coracoacromial ligament relaxes the coracohumeral ligament leading to an increased cranio-caudal instability. The posterior inferior ligament is complementary to the anterior inferior ligament thus stabilizing the shoulder joint in abduction and internal rotation. Sparing this structure in arthroscopy with dorsal portals and restoring in the case of a rupture seems to be of value for a normal joint function.

In a prospective study we evaluated diagnostic ultrasound investigation for shoulder instabilities. We measured the passive aptranslation In 150 healthy persons in relation to the dorsal glenoid as well as the inferior subluxation in relation to the acromion. After establishing normative datas we measured 23 patient with unidirectional instabilities and 34 with multidirectional instabilities. The humeral head position of a normal joint is 8 to 10 mm dorsally to the glenoid. In the control group the anterior translation of the dominant shoulder is significantly higher as in the nondominant shoulder (student-t-test; p less than 0.0045). Patients with anterior instabilities showed a significant increase of anterior translation in the injured shoulder (student-t-test; p less than 0.0001). In comparison with the control group there is a significant increase of downward subluxation in patients with multidirectional instabilities (chi 2 alpha less than 0.05). In habitual or voluntary dislocations the relation of the humeral head to the glenoid can be judged statically and dynamically. Secondary signs of dislocation (Hill-Sachs lesions, joint effusion) are evident.

In a prospective study we examined 107 patients suffering from an acute trauma or a chronic disease of the knee joint by MRI. The MRI results were compared to the results of arthroscopy. Normal anatomical structures can be differentiated and there is a high diagnostic reliability for lesions of the medial (accuracy: 91%, predictive value: 84%) and lateral (accuracy: 93%, predictive value: 79%) meniscus, complete tears of the anterior cruciate ligament (accuracy: 93%, predictive value: 75%), chondropathia of the patella, and osteochondritis dissecans. Partial ruptures of the ACL as well as small cartilage defects could usually not be demonstrated.

31 healthy persons had to run on a treadmill under defined conditions at a constant speed of 8 km/h. Pressure in the anterior flexor-muscles compartment was measured regulary in time before, during and after running; the size of the compartment was documented by sonography. The measured pressure was attached to the respective compartment size. The runners were divided into three groups based on characteristic pressure-courses: the normal-type with average values below 50 mmHg, the indifference-type with a distinctly higher pressure than 50 mmHg and the risk-type with values more than 70 mmHg. A correlation between exercise-pressure and time of post-exercising decrease of pressure was found. While the normal type reached the starting pressure within 6 minutes the indifference and risk type didn't succeed in decreasing after this period of time. No change of compartmental size was measured while the pressure increased on exertion.