BACKGROUND:Aim of this study was to measure the clinical and radiological longterm outcome after acetabular revision arthroplasty (RTHA) using the Müller acetabular reinforcement ring.MATERIAL AND METHODS:86 patients with 90 revision arthroplasties and a mean age of 68 years (41 to 84) were included. The mean follow-up was 10 years (range 7-12). The Harris Hip Score and the WOMAC Index were used to assess pain and functional outcome. Furthermore clinical examination of range of motion and radiologic examinations were performed in 34 patients.RESULTS:The radiologic analysis reports no signs of loosening in 79%, 15% showed possibly loosening and 6% probable loosening. Definite radiologic loosening has not been detected. In the meantime 12 patients (13.3%) of 90 revision total hip arthroplasty underwent a revision of the acetabulum with change of the acetabular component which means a survival rate of 86.7% after 10 years follow-up. The mean center of rotation of the hip moved 0.15 cm (SD 0.74 cm) laterally and 0.1 cm (SD 0.97 cm) cranially based on the geometrically reconstructed center of rotation. A mean score of 58 points for the Harris Hip Score (range 14-93) indicated a poor functional outcome, while a mean value of 96 points (range 0-223) for the WOMAC Index indicated good results for functional outcome in daily living.CONCLUSIONS:The revision arthroplasty in cases with acetabular defects using the Müller acetabular reinforcement ring shows acceptable longterm results.LEVEL OF EVIDENCE:Level IV.

BACKGROUND:Stress shielding of the proximal femur has been observed in a number of conventional cementless implants used in total hip arthroplasty. Short femoral-neck implants are claiming less interference with the biomechanics of the proximal femur. The goal of this study was to investigate the changes of bone-mineral density in the proximal femur and the clinical outcome after implantation of a short femoral-neck prosthesis.METHODS:We prospectively assessed the clinical outcome and the changes of bone mineral density of the proximal femur up to one year after implantation of a short femoral neck prosthesis in 20 patients with a mean age of 47 years (range 17 to 65). Clinical outcome was assessed using the Harris Hip Score. The WOMAC was used as a patient-relevant outcome-measure. The bone mineral density was determined using dual energy x-ray absorptiometry, performed 10 days, three months and 12 months after surgery.RESULTS:The Harris Hip Score improved from an average preoperative score of 46 to a postoperative score at 12 months of 89 points, the global WOMAC index from 5,3 preoperatively to 0,8 at 12 months postoperatively. In contrast to conventional implants, the DEXA-scans overall revealed a slight increase of bone mineral density in the proximal femur in the 12 months following the implantation.CONCLUSION:The short femoral neck stem lead to a distinct bone reaction. This was significantly different when compared to the changes in bone mineral density reported after implantation of conventional implants.

Problem: The anatomically shaped pcl (ESKA) total hip replacement has a porous coating of the proximal stem and the cup to allow for bony ingrowth. The tip of the stem is polished.Method: We report the results of 96 THR 6,2 years (5,25-6,7) after implantation.Results: There were no revisions during this period. One stem showed radiographic loosening at follow-up. There was stress-shielding in 9,4% in contrast to the concept of proximal fixation. Thigh-pain was found in 9,4%. One patient demonstrated disabling thigh-pain despite radiologic bony ingrowth. By drilling the femur distal to the tip of the stem a remarkable relief was achieved.Conclusion: Despite numerous cases of stress-shielding (9,4%), bony ingrowth occurs in 97%. The tcl-THR performs sufficiently after 6 years of implantation.

Zu sam men fas sung Die Be reit stel lung ei ner suf fi zi en ten post ope ra ti ven Schmerz the ra pie stellt eine Ver pflichtung in der Pa ti en ten ver sor gung dar. Ein brei tes Spekt rum an me di ka men tö sen, tech nischen und or ga ni sa to ri schen Op tio nen wird in der Or tho pä die und Un fall chi rur gie ange wandt. Die Schmerz mes sung ist eben so wich tig, wie die rich ti ge An wen dung von Anal ge ti ka bzw. Ap pli ka ti ons ver fah ren. Schmerz the ra pie stan dards sol len des halb zu ei ner mög lichst gro ßen Selbst stän dig keit in der Schmerz be hand lung ope rier ter Pa ti en ten führen. Er gän zend wer den spe zi el le Schmerz the ra pie ver fah ren zur in di vi du el len oder opera ti onss pe zi fi schen Be hand lung be nö tigt, wie die pa ti en ten kon trol lier te An al ge sie oder die Ner ven ka the ter ver fah ren. Die ba lan cier te post ope ra ti ve An al ge sie kann Ne ben wirkungsund Kom pli ka ti ons ra ten sen ken, die Mo bi li sier bar keit der Pa ti en ten stei gern und de ren Zu frie den heit för dern.

Provision of sufficient post-operative pain therapy is an obligation in the clinical management of patients. A wide range of medical, technical and organizational options is used to improve post-operative pain management in orthopaedic surgery. Measurement of pain is as important as the correct use of analgesics and application techniques. Standardized pain therapy algorithms should facilitate autonomous treatment of patients. Additional procedures like patient-controlled analgesia or local catheter for pain are necessary for individualized or operation-specific pain therapy. The balanced combination in post operative pain therapy could reduce side effects and complication rates, increase mobility and enhance patient satisfaction.

Objective: To assess the inter-observer and intra-observer reliability of two commonly used radiographic classification systems in the evaluation of hip dysplasia in skeletally mature adults. Design: Three observers with different levels of training independently classified 62 dysplastic hips on 51 standard anteriorposterior pelvis radiographs according to the criteria defined by Crowe and by Hartofilakidis. To assess intra-observer reliability, the same radiographs were reviewed 3 months later by the same observers. Patients: At the time of the radiographic examination, the mean age of the 51 patients had been 54 years (range 18-82 years). Results: A high correlation concerning the inter- and intra-observer reliability of both systems was demonstrated. Inter-observer reliability displayed a weighted kappa coefficient of 0.82 for the Crowe and 0.75 for the Hartofilakidis classification. Intra-observer reliability showed a kappa coefficient of 0.86 and 0.79, respectively. Conclusions: Both classification systems can be recommended to compare collectives of adult patients with congenital dysplasia of the hip. However, for future clinical practice, it would be advisable to agree on one universally accepted system as a standard in the literature.

Objective: Increasing bone mineral density (BMD) has been found in several studies in patients with osteoarthritis (OA). Therefore, the simultaneous occurrence of osteoporosis (OP) and OA is denied by many clinicians. Because of our clinical impression, however, we suggest that we have to consider a common occurrence. In the present study we have examined the relationship between osteoathritis of the knee or the hip and osteoporosis. Method: The BMD of the lumbar spine and the proximal femur of 117 OA patients (82 postmenopausal female patients aged 50-83 and 35 male patients aged 36-86 years) who subsequently required hip or knee replacements, but were otherwise healthy, was measured by dual-energy X-ray absorptiometry (DXA; Hologic QDR-2000). The results are given as required by the WHO and the new German guidelines of the DVO. The BMD was measured and categorised in a sex-related manner and the occurrence of disuse osteoporosis on the affected limb was examined. Furthermore, a comparison was made in the level of BMD between the OA of the involved hip or knee. Results: There was a high occurrence of low BMD among the patients. 23.2% of the women were affected by OP. This reflects the normal distribution of OP in the female population. 20% of the male patients had occult OP. This is astonishingly high. Osteopenia was measured for 37.1% of the male patients and 42.7% of the female patients. Age proved to be a significant factor in the degree of BMD. Neither a disuse osteoporosis, nor a significance in the OA-affected joint to the degree of BMD, could be proven. Conclusion: We cannot support the hypotheses that OA prevents OP. Moreover, the occurrence of OP in our study reflected the incidence of OP in the average female and was astonishingly high in the male population; this does not support the hypothesis that the two conditions are mutually exclusive. Also a lower risk of fractures among OA patients cannot be concluded. There is current open discussion whether a known BMD should influence the decision for a cemented or an uncemented prosthesis.

The aim of this study was to determine the accuracy of the software system "Düsseldorf Migration Analysis - Femoral Component Analysis" (DMA-FCA) in measuring stem migration in total hip arthroplasty (THA) on digitised anteroposterior radiographs of the pelvis. Bony and implant landmarks on two consecutive radiographs were used for measurements of subsidence and varus-valgus tilt. The accuracy of the method was determined by reference to radiostereometric measurements (RSA). Using specific comparability limits, comparability analysis of radiographs with respect to femoral positioning is possible with DMA. DMA-FCA and RSA measurements were performed after cementless THR in a population of 60 patients aged 38 to 69 years. With a Cronbach's alpha-index of 0.89 and 0.99 for subsidence and 0.90 and 0.98 for classic varus-valgus-tilt, the intraobserver and interobserver reliability for the DMA-FCA-method was calculated as good. Using RSA as reference method, the accuracy of DMA-FCA was calculated to be 2.51 mm for subsidence and 2.49 degrees for varus-valgus-tilt (95% confidence interval). Without comparison to RSA, DMA measured 1.94 mm for subsidence and 2.35 degrees for varus-valgus-tilt. Based on a comparison with RSA, our results show lower accuracy for DMA-FCA than for EBRA-FCA, but DMA-FCA is easier to use in everyday clinical practice. It is hoped that the use of digital measuring methods such as DMA will become standard for long-term observation and will be integrated into clinical routine in the context of quality assurance of THR.

Aim: Decreases in depth and irregularity are typical changes of the acetabulum in patients with Perthes disease and develop secondary to the femoral head involvement. Optimal timing of therapy plays an important role to prevent these secondary changes. The present study investigates the influence of the amount of femoral head involvement and the patients' age on the acetabulum and the outcome. Methods: 66 patients with 76 affected hip joints were included in the study. 20 hips had a conservative therapy, 22 an operative therapy (IVO). 34 hip joints underwent a conservative therapy at first, followed by an operative intervention. The radiomorphometric analyses at the time of diagnosis, pre- and postoperatively and at follow-up were performed with epiphyseal ratio, acetabular ratio and acetabulum-head ratio. At the time of diagnosis the patients were classified with the Catterall classification, at follow-up with Mose classification. Results: Independent from therapy there was a correlation of the parameters with Catterall classification over the whole course, i.e., the higher the Catterall group the worse the parameter at the time of diagnosis as well as at follow-up. Operatively treated patients with Catterall IV tended towards a worse result of the epiphyseal ratio whereas they achieved better results in the other parameters compared to conservatively treated patients. Catteral I and II patients achieved good results. Conclusion: Operative treatment of the higher Catterall groups seems to be more effective than conservative therapy. Secondary changes of the acetabulum develop in proportion to the amount of femoral head involvement.

AIM:Decreases in depth and irregularity are typical changes of the acetabulum in patients with Perthes disease and develop secondary to the femoral head involvement. Optimal timing of therapy plays an important role to prevent these secondary changes. The present study investigates the influence of the amount of femoral head involvement and the patients' age on the acetabulum and the outcome.METHODS:66 patients with 76 affected hip joints were included in the study. 20 hips had a conservative therapy, 22 an operative therapy (IVO). 34 hip joints underwent a conservative therapy at first, followed by an operative intervention. The radiomorphometric analyses at the time of diagnosis, pre- and postoperatively and at follow-up were performed with epiphyseal ratio, acetabular ratio and acetabulum-head ratio. At the time of diagnosis the patients were classified with the Catterall classification, at follow-up with Mose classification.RESULTS:Independent from therapy there was a correlation of the parameters with Catterall classification over the whole course, i.e., the higher the Catterall group the worse the parameter at the time of diagnosis as well as at follow-up. Operatively treated patients with Catterall IV tended towards a worse result of the epiphyseal ratio whereas they achieved better results in the other parameters compared to conservatively treated patients. Catteral I and II patients achieved good results.CONCLUSION:Operative treatment of the higher Catterall groups seems to be more effective than conservative therapy. Secondary changes of the acetabulum develop in proportion to the amount of femoral head involvement.

OBJECTIVE:Increasing bone mineral density (BMD) has been found in several studies in patients with osteoarthritis. Therefore, many clinicians deny the simultaneous occurrence of osteoporosis (OP) and osteoarthritis (OA). Because of our clinical impression however, we suggested that we have to consider a common occurrence. Furthermore, the value of markers of bone turn over with a view to early diagnosis of OP and or as an assessment for bone metabolism in OA is still a matter debate and their clinical use has not been clearly defined in the management of the individual patient.METHOD:The BMD of the lumbar spine and the proximal femur of 119 OA patients (83 postmenopausal female patients aged 50-83 and 35 male patients aged 36-86 years) who subsequently required hip or knee replacements, but were otherwise healthy, were measured by dual energy X-ray absorption (DXA), Hologic QDR-2000. We also measured biochemical markers of bone turn over, i. e., CICP, ICTP, DPD, PTH, estrogen, testosterone, bAP, hydroxy vitamin D and the normal blood count.RESULTS:There was a high occurrence of a low BMD among the patients. A total of 28.9% of women were affected by OP and 52.9% by osteopoenie. This reflects the normal distribution of OP in the female population. Of the male patients 20% had OP and 38.8% osteopoenie. This is astonishing high. Age proved to be a significant factor in the degree of BMD. An association between disuse osteoporosis and degree of BMD in the OA affected joint could not be proven. The use of the biochemical markers for an earlier diagnosis or to assess bone metabolism in OP and OA was not possible.CONCLUSION:We can not support the hypotheses that OA prevents OP. Moreover, the occurrence of OP in our study reflected the incidence of OP in the average female and the astonishingly high incidence in the male population; however does not mean that the two conditions are mutually exclusive. We did not find that the biochemical markers of bone turn over could deliver additional information with respect to bone metabolism and an earlier diagnosis of OP.

AIM:We investigated the initial stability of cementless stems implanted with robotic milling and conventional manual broaching.METHODS:Proximally porous structured stems (G2, ESKA-Implants, Luebeck, Germany) were implanted into synthetic femora. In one group, the femoral cavity was prepared by a CT-based robot (CASPAR, URS-Ortho, Germany) with a high-speed milling head. In the other group, femora were rasped manually with broaches. The broaches had 1 mm proximal press-fit, the robotic cavities 1.5 mm. The implants were exposed to 15 000 loading cycles with 1 000 +/- 500 N. The direction of forces on the implant head were chosen to simulate stair climbing. Internal rotation and translation (caudal, dorsal and lateral) of the implants were measured by linear transducers.RESULTS:The robotic group showed significantly less reversible motion regarding translation in caudal, dorsal and lateral directions. The standard deviations of implant motions were smaller in the robotic group.CONCLUSION:Using robotic preparation of the femur, initial stability was higher and more consistent than with manual broaching, but differences in undersizing of the cavities created in the femur in relation to the implant may have contributed to these differences for the most part. In-vitro-loading experiments focusing on femoral cavities with varying press-fits are recommended before the introduction of new implants or operating procedures.

BACKGROUND:Accurate alignment of the components in total knee arthroplasty is important. By use of postoperative CT controls, we studied the ability of a robotic effector to accurately place and align total knee arthroplasty (TKA) components according to a purely CT-based preoperative plan. PATIENTS AND METHODS:Robotic TKA was performed in 13 patients (6 men) with primary gonarthrosis. Locator screws were placed into femur and tibia under spinal anesthesia. A CT-scan including the femoral head, knee and ankle was performed. In the preoperative planning software, virtual components were positioned into the CT volume. In a second operation, the robot milled femur and tibia with a high-speed milling tool according to the preoperative plan. On the 10th day, CT controls were performed following the same protocol as preoperatively. RESULTS:The mean deviation of the postoperative from the preoperatively planned mechanical axis was 0.2 degrees (95% CI: -0.1 degrees to 0.5 degrees ). The accuracy of angular component placement in frontal, sagittal and transverse planes was within +/-1.2 degrees , and the accuracy of linear component placement in mediolateral, dorsoventral and caudocranial directions was within +/-1.1 mm. INTERPRETATION:Robotic TKA allows placement of components with unparalleled accuracy, but further development is mandatory to integrate soft-tissue balancing into the procedure and make it faster, easier and cheaper.

With suitable application and signal processing methods, surface electromyography is a-comparatively simple instrument for investigating the temporal pattern of the muscular activity of a walking subject. The influence of changes both in the external experimental conditions (e.g. orthopedic shoe design) and in the human locomotor system (due to disease or therapy) on the individual muscular gait characteristics can be documented in this way. The usefulness of this kind of investigation is basically limited by the reproducibility of the gait analytical findings of the subject, who is examined at different times with unchanged bodily state and under identical experimental conditions unchanged. In our experiments we observed that the reproducibility of electromyographic activity curves obtained by ensemble averaging over a sufficiently high number of full strides differs for different muscles and in different subjects. Within the same experimental session it is very high and considerably better than in experiments done on different days. In examinations done on different days the basic characteristics of the activity curves are reproduced better than the absolute height of the amplitudes. In view of these findings the differences observed in the gait analysis of patients in the course of operative or conservative therapy have to be interpreted very carefully as to their true origin.

AIM:The aim of this study was to analyse the relation between the mobility of the thoracic spine and an impingement syndrome of the shoulder.METHOD:In a prospective study, 50 patients with an impingement syndrome and 50 healthy test subjects were examined for the mobility of their thoracic spines. All patients and test subjects were examined according to a standardized protocol. The experiments were carried out in the biomechanical laboratory of our clinic with the Plurimetercompass and the Inclinometer of Rippstein.RESULTS:In 23 patients a tendinosis calcarea was diagnosed radiologically, 27 patients suffered from a plain impingement without calcification, hence both groups were analyzed separately. The mobility of the thoracic spine in the sagittal and frontal planes and in rotation was significantly different between the three groups. The highest mobility was found in the healthy test subjects, the lowest in patients with a plain impingement. No differences were found concerning the initial posture of the thoracic spine.CONCLUSION:There is a relation between mobility of the thoracic spine and an impingement syndrome. This should be respected in diagnosis and therapy.

Studienziel: Ziel der vorliegenden Studie war es, den Zusammenhang zwischen BWS-Beweglichkeit und einem Impingementsyndrom zu untersuchen. Methode: In einer prospektiven Studie wurden 50 Patienten mit einer Impingementsymptomatik und 50 schultergesunde Probanden auf ihre BWS-Beweglichkeit hin untersucht. Alle Probanden und Patienten wurden nach einem standardisierten Untersuchungsbogen klinisch evaluiert. Die experimentellen Untersuchungen erfolgten im Biomechaniklabor der Klinik mittels Plurimeterkompass und Inklinometer nach Rippstein. Ergebnisse: Bei 23 Patienten bestand radiologisch eine Tendinosis calcarea, 27 Patienten wiesen eine reine Impingementsymptomatik auf, so dass beide Gruppen von den gesunden Probanden unterschieden wurden. Die Beweglichkeit der BWS in der Sagittal-, Frontalebene und der Rotation unterschied sich signifikant zwischen den drei Gruppen. Die größte Beweglichkeit wiesen die gesunden Probanden, die geringste die Patienten mit reinem Impingementsyndrom auf. Signifikante Unterschiede bezüglich der Ausgangsstellung im Sitzen wurden nicht gefunden. Schlussfolgerung: Es besteht ein Zusammenhang zwischen BWS-Beweglichkeit und dem Vorliegen eines Impingementsyndroms. Dies sollte in Diagnostik und Therapie berücksichtigt werden.

Background There is conflicting evidence regarding extracorporeal shock wave treatment for chronic tennis elbow. Hypothesis Treatment with repetitive low-energy extracorporeal shock wave treatment is superior to repetitive placebo extracorporeal shock wave treatment. Methods Seventy-eight patients enrolled in a placebo-controlled trial. All patients were tennis players with recalcitrant MRIconfirmed tennis elbow of at least 12 months’ duration. Patients were randomly assigned to receive either active low-energy extracorporeal shock wave treatment given weekly for 3 weeks (treatment group 1) or an identical placebo extracorporeal shock wave treatment (sham group 2). Main outcome measure was pain during resisted wrist extension at 3 months; secondary measures were >50% reduction of pain andthe Upper Extremity Function Scale. Results At 3 months, there was a significantly higher improvement in pain during resisted wrist extension in group 1 than in group 2 (mean [SD] improvement, 3.5 [2.0] and 2.0 [1.9]; P= .001 for between-group difference of improvement) and in the Upper Extremity Function Scale (mean [SD] improvement, 23.4 [14.8] and 10.9 [14.9]; P< .001 for between-group difference of improvement). In the treatment group, 65% of patients achieved at least a 50% reduction of pain, compared with 28% of patients in the sham group (P= .001 for between-group difference). Conclusion Low-energy extracorporeal shock wave treatment as applied is superior to sham treatment for tennis elbow.

With suitable application and signal processing methods, surface electromyography is a comparatively simple instrument for investigating the temporal pattern of the muscular activity of a walking subject. The influence of changes both in the external experimental conditions (e.g. orthopedic shoe design) and in the human locomotor system (due to disease or therapy) on the individual muscular gait characteristics can be documented in this way. The usefulness of this kind of investigation is basically limited by the reproducibility of the gait analytical findings of the subject, who is examined at different times with unchanged bodily state and under identical experimental conditions unchanged. In our experiments we observed that the reproducibility of electromyographic activity curves obtained by ensemble averaging over a sufficiently high number of full strides differs for different muscles and in different subjects. Within the same experimental session it is very high and considerably better than in experiments done on different days. In examinations done on different days the basic characteristics of the activity curves are reproduced better than the absolute height of the amplitudes. In view of these findings the differences observed in the gait analysis of patients in the course of operative or conservative therapy have to be interpreted very carefully as to their true origin.