[Periprosthetic fractures of the acetabulum and femur : Causes-classification-treatment algorithms]. / Periprothetische Frakturen des Acetabulums und des Femurs : Ursache ­ Klassifikation ­ Therapiealgorithmen.

BACKGROUND: Both increasing implantation numbers of total hip replacements and demographic change with higher populations of older people, indicate that there will be an increase in periprosthetic fractures in the future. CAUSES: Falls in the home environment are the most common cause. Significant co-factors include reduced patient coordination, reduced bone quality, or implant-associated factors such as local osteolysis or pre-existing implant loosening. CLASSIFICATION: In the classification of periprosthetic fractures of the femur, the Vancouver classification has prevailed in recent years, which in addition to a description of the localization of the fracture also considers the stability of the prosthesis and bone quality. Based on this, therapeutic algorithms have been developed that can vary from the conservative approach via osteosynthetic options to a replacement of the prosthesis. In order to allow the description of periprosthetic fractures on all joints, the Vancouver classification has been extended to the UCS classification by including the AO/OTA bone and joint coding system. In the selection of the treatment method, the consideration of individual patient factors such as activity level and secondary diagnoses is essential. Based on the established classifications, the importance of the different therapeutic methods is presented.

The Impact of Pinless Navigation in Conventionally Aligned Total Knee Arthroplasty.

BACKGROUND: Restoration of the mechanical axis is a main objective in total knee replacement (TKR). Aim of this study was to analyse the verification tool of a pinless navigation system in conventional TKR (cTKR). METHODS: In a prospective study, 147 TKR were performed by conventional technique. Using the "pinless verification" mode of a smartphone based navigation system, the cutting block position and final resection plane for distal femur and proximal tibial resection were measured. If necessary, the block position or resection level were optimized, corrections were protocolled. Postoperatively, standardized radiographs were performed. RESULTS: In 65.3%, intraoperative measurements changed the surgical procedure (corrections: 20.4% femoral, 25.9% tibial, 19% both). The additional time for surgery compared to cTKR averaged 6 minutes (79 ± 15 versus 73 ± 17 minutes). Using navigation data, the final femoral and tibial axes were in 93% within a range of ±2°. A mean difference of 1.4° and 1.6° could be shown between the final measurement of the navigation system and the postoperative mLDFA and mMPTA. CONCLUSION: Intraoperative pinless navigation has impact on the surgical procedure in the majority of cTKR. It represents a less time-consuming tool to improve implant position while maintaining the routine of conventional technique.

[Acute acromioclavicular joint injuries. Changes in diagnosis and therapy over the last 10 years]. / Die akute Schultereckgelenkverletzung. Diagnostik, Therapie und Entwicklungen der letzten 10 Jahre.

BACKGROUND: The goal of the present study was to summarize current treatment for acute acromioclavicular (AC) joint dislocations. METHOD: In all, 796 orthopedics and/or trauma departments in Germany were identified in the national hospital directory (www.dka.de). Using the respective hospital web sites, the email addresses of the responsible shoulder/sports surgeon or, if not available, the head of department (successful in 746 cases) were identified. Emails with a link to an online survey with 36 questions and two reminders were sent; 60 were undeliverable. Thus, 686 emails probably reached the addressee. A total of 203 colleagues (30%) participated in the survey. Findings were compared to results of the survey published by Bäthis et al. in 2001. RESULTS: More than 90% treat Rockwood I or II injuries conservatively and Rockwood IV to VI injuries surgically. However, 34% answered having never seen a Rockwood VI injury. Of those replying, 73% prefer surgical treatment for Rockwood III injuries. Favored surgical techniques were the hook plate in 44% and the arthoscopic TightRope® in 27%, while 11% prefer coracoclavicular cerclage, 6% AC joint transfixation, 3% minimally invasive AC joint reconstruction (MINAR), 1% coracoclavicular screw fixation, and 8% a completely different procedure. Concerning acute Rockwood III injuries, orthopedics and/or trauma surgeons still prefer surgical treatment but less often than 10 years ago (84%). CONCLUSIONS: Favored techniques have completely changed since 2001 when the majority of physicians preferred AC joint transfixation or coracoclavicular cerclages, both techniques that are hardly used today. The hook plate appears to have become "standard therapy". The arthroscopic TightRope® is the second most common despite being the newest technique.

[Prevention of infection in the current treatment of open fractures: an evidence-based systematic analysis]. / Prävention von Infektionen bei offenen Frakturen heute: Ein evidenzbasierter systematischer Review.

BACKGROUND: Treatment of open fractures remains an interdisciplinary challenge. Even success and evidence of infection prevention especially of new treatment options is not clear. METHOD: A systematic search in available electronic databases over the years 1974 until 2011 was conducted. Only clinical analyses with more than 5 adult patients in the German, English or French languages were included. All studies were rated according to Centre for Evidence-Based Medicine (CEBM) criteria. RESULTS: Over 855 articles were found due to the search and after applying the exclusion and inclusion criteria 49 studies were finally assessed to contribute to the evidence-based recommendations. Grade A recommendation: early application of antibiotics against gram-positive organisms for all open fracture types, additional coverage of gram-negative organisms for type III open fractures. Early surgical debridement should be performed. Grade B recommendation: type III open fractures should be treated with antibiotics for a minimum of 72 h but not longer than 24 h after wound closure. Vacuum treatment is justified and beneficial if wound closure is not achieved. Grade C recommendation: additional local antibiotic treatment in combination with systematic antibiotics may be of benefit. Definitive wound closure should be achieved within 1 week. DISCUSSION: This evidence-based analysis shows that there is good evidence for the treatment of open fractures with antibiotics and surgical debridement. Vacuum treatment can be recommended if wound closure is not possible.

A five to seven year follow-up comparing computer-assisted vs freehand TKR with regard to clinical parameters.

PURPOSE: Computer-assisted knee surgery has become established in routine clinical practice. Still, there is no study investigating midterm clinical outcome after five to seven years postoperatively. We aimed to test the hypothesis that there is no difference either for subjective [Western Ontario and McMaster Universities (WOMAC) scores] or for objective (Knee Society Score, degree of flexion) criteria between computer-assisted total knee replacement (TKR) and freehand TKR after 5.6-7.3 years. METHODS: We performed a matched-pair analysis; 100 patients who received a primary TKR were investigated after a median follow-up of 6.25 years. Group A was operated on with the support of a computer system, while surgery on patients in group B was performed with the freehand technique. We determined WOMAC Score, Knee Society Score and degree of flexion. RESULTS: Overall we found similar results for WOMAC Score [group A: 42.98 (SD 13.80); group B: 41.54 (SD 15.01; p = 0.62)], Knee Society Score [group A: 168.20 (SD 21.94); group B: 166.60 (SD 21.44; p = 0.71)] and range of motion [group A: 106° (SD 9.19); group B 107° (SD 7.44; p = 0.62)]. CONCLUSIONS: No significant differences in midterm clinical outcome were found after TKR performed in the freehand vs computer-assisted technique.

[Advanced Trauma Life Support (ATLS) in the emergency room. Is it suitable as an SOP?]. / Schockraummanagement von Schwerverletzten. Eignet sich ATLS als SOP?

There is clinical evidence that a standardized management of trauma patients in the emergency room improves outcome. ATLS is a training course that teaches a systematic approach to the trauma patient in the emergency room. The aims are a rapid and accurate assessment of the patient's physiologic status, treatment according to priorities, and making decisions on whether the local resources are sufficient for adequate definitive treatment of the patient or if transfer to a trauma center is necessary. Above all it is important to prevent secondary injury, to realize timing as a relevant factor in the initial treatment, and to assure a high standard of care. A standard operating procedure (SOP) exactly regulates the approach to trauma patients and determines the responsibilities of the involved faculties. An SOP moreover incorporates the organizational structure in the treatment of trauma patients as well as the necessary technical equipment and staff requirements. To optimize process and result quality, priorities are in the fields of medical fundamentals of trauma care, education, and fault management. SOPs and training courses increase the process and result quality in the treatment of the trauma patient in the emergency room. These programs should be based on the special demands of the physiology of the trauma as well as the structural specifics of the hospital. ATLS does not equal an SOP but it qualifies as a standardized concept for management of trauma patients in the emergency room.

[Surgical training in orthopaedic and trauma departments in Germany]. / Die operative Weiterbildung an deutschen orthopädischen und traumatologischen Kliniken.

AIM: Training in surgical skills is not at its best in German hospitals in comparison to other countries. There is no detailed curriculum describing which operations a resident has to learn at which stage of his training as in Switzerland or Denmark. We aimed to find out how many typical operations are performed by trainees/residents in orthopaedic surgery. METHOD: We performed a survey at Orthopeadic and Trauma Departments in Germany to measure the percentage of operations (knee arthroscopies, shoulder arthroscopies and knee arthroplasties) which are performed by trainees and residents. RESULTS: Retrospective data were evaluated. Out of 35 654 knee arthroscopies, 49.4% were performed by the head of department or senior consultants, 27.6% by junior consultants and 26.9% by trainees. A total of 30,642 shoulder arthroscopies was analysed. 78.4% were operated on by the head of department or senior consultants, 18.3% by junior consultants and 6.9% by trainees. We evaluated 31,138 knee arthroplasties, 80% were operated by the the head of department or senior consultants, 14% by junior consultants and 7% by trainees. CONCLUSION: Surgical training is still not at its best for trainees. Further improvement is necessary to create a transparent training environment for younger surgeons.

Two year follow-up comparing computer assisted versus freehand TKR on joint stability, muscular function and patients satisfaction.

Computer assisted (CAS) knee surgery has been established in clinical routine. There is still no study that investigates clinical outcome. Fifty patients who received a primary total knee replacement 2 years before were investigated. These patients were divided into two groups of matched-pairs; group A was operated in the freehand technique and group B with support of a computer system. We compared Womac score, Knee Society score, range of motion, leg alignment, knee stability and isokinetic muscle strength. We found similar results for WOMAC, Knee Society score and isokinetic muscle force. Stability and range of motion revealed slightly better values for the CAS group. A statistically significant difference could only be demonstrated for postoperative leg alignment. Two years after freehand versus computer assisted TKR we found slightly better values for range of motion and ligamentous stability. Only postoperative leg alignment was statistically better in the CAS group.

[Knee ligament injuries]. / Ligamentäre Knieverletzungen in der Praxis.

Like no other joint of the human body the knee depends on intact ligaments. Knee instability due to ligament injuries will cause abnormal joint kinematics, and thereby is made responsible for secondary damage to other important knee joint structures. Diagnosis of knee ligament injuries is based on the detailed history with often typical injury patterns, as well as on the physical examination with specific knee ligament tests. In addition radiological evaluation is used. The range of knee ligament injuries is wide. Beginning with an isolated medial collateral ligament rupture which will heal with conservative treatment, they range to knee dislocation, a serious injury which needs emediate care and is associated with a high incidence of complications. Surgical procedures aim to reconstruct knee ligaments as anatomical as possible to provide for a long term stable knee joint.

[Prevention of deep vein thrombosis in total knee replacement--current status of therapy in orthopedie and trauma departments in Germany]. / Thromboseprophylaxe in der Knieendoprothetik. Stand der Therapie an deutschen orthopädisch-traumatologischen Kliniken.

INTRODUCTION: Symptomatic deep vein thrombosis is a serious complication after total knee arthroplasty, with a risk of about 4-5% despite prevention with herparin. Aim of the current study was to find out about the actual status of thrombosis prophylaxis in Germany after total knee replacement. MATERIAL AND METHODS: In a countrywide survey 470 German trauma and orthopaedic surgery departments were asked about their prophylactic procedures addressing deep vein thrombosis after total knee replacement. RESULTS: 98% perform prevention of thrombosis with low-molecular-weight heparin, 2% use unfractioned heparin. Low-molecular-weight heparin is applicated in standard doses in 48% and in 44% according to patient's weight. In 82% the prophylaxis is begun the night before surgery. The therapy is carried out for 4.7 weeks in mean. 96% use graduated compressions stocking as additional therapeutic option. CONCLUSION: Our survey shows that most of the surgeons perform prevention of deep vein thrombosis according to the official guidelines.

[Are computer assisted total knee replacements more accurately placed? A meta-analysis of comparative studies]. / Sind navigierte Knieendoprothesen tatsächlich präziser implantiert? Eine Metaanalyse vergleichender Studien.

Computer-assisted surgery (CAS) has become established in many hospitals throughout the world, especially in the form of computer navigation for total knee replacement (TKR). Analysis of the studies available revealed 18 comparative studies examining the precision of implantation of knee endoprostheses following CAS and after implantation by the conventional technique. In a meta-analysis of 13 studies in which the same safe zone of +/-3 from neutral alignment was defined for the leg axis, a total of 1,784 TKR were performed. In the group of patients in whom the conventional technique was used, 75.6% (654/865) of TKR were implanted within the safe zone. In the CAS group 93.9% (863/919) of the prostheses were implanted within the safe zone (p<0.0001). The differences between the groups were statistically significant in 11 of the 13 studies, and the difference between groups for the entire patient population is highly significant. Only limited clinical results were ascertained in these comparative studies; there were no great differences between the treatment groups in clinical course.

[Revision prosthetic of the knee joint. The influence of a navigation system on the alignment and reconstruction of the joint line]. / Revisionsendoprothetik des Kniegelenks. Einfluss eines Navigationssystems auf das Alignment und die Rekonstruktion der Gelenklinie.

Recognizing the rising number of primary total knee arthroplasties (TKA) over the last decade, one may assume an increasing number for revisions after a certain time delay. Studies showing a rate of only 78% satisfied patients provide a hint that there is still room for improvement. Therefore, it seemed worthwhile to evaluate the benefits of the computer assisted technique in revision TKA and compare the alignment results with the conventional technique. In a prospective study, 120 patients were operated for revision TKA using either the Vector-Vision navigation system (n=60) or the conventional technique (n=60). The axial limb alignment was evaluated on standardized pre- and postoperative full length weight-bearing radiographs and the variation of the joint line was determined by the method of Figgie from 1986.A precise reconstruction of the mechanical limb axis was achieved in 57/60 Patients (95%) in the computer assisted group and in 48/60 (80%) in the conventional group. A reconstruction of the joint line with a variation of less then 4 mm was achieved in 47/60 (78%) in the computer assisted and in 33/60 (55%) in the conventional group. Revision TKA remains a challenging procedure for the surgeon. Modern navigation systems offer additional information intraoperatively and might therefore simplify the procedure. In particular, the adjustment of the extension and flexion gap and the reconstruction of the joint line the results were superior. Furthermore, the use of a CT-free navigation system provides a significant improvement of prosthesis and leg alignment in revision TKA.

[Advances in soft tissue management in total knee arthroplasty. The use of imageless navigation systems]. / Fortschritte im Weichteilmanagement in der Knieendoprothetik. Einsatz von bildfreien Navigationssystemen.

Computer aided surgery has become established in the clinical routine over the past years. There are some very good studies which show that navigation optimizes reconstruction of the leg axis in total knee replacement. The question of why outliers occur in spite of navigation has to be asked. It is clear that total knee replacement is not only a bony procedure, but the soft tissues have an immense influence on postoperative stability of the prosthesis over the full range of movement. Current navigation systems allow visualization of the leg axis and size of the extension and flexion gap, and support the surgeon during soft tissue management. The current paper shows how the anatomic approach and the position of the patella influence soft tissue tension and support the surgeon during release of soft tissues in severe leg axis deformities.

Computer assistance in total knee replacement - a critical assessment of current health care technology.

The last five years have seen the rapid development of computer assisted surgery (CAS) in total knee replacement (TKR). Many surgeons perform TKR using navigation systems, which offer user-friendly workflows and reproducible results. A number of level 1 and 2 studies, according to evidence-based medicine criteria, have demonstrated that navigation in TKR allows a more precise implantation of the prosthesis, though CAS still requires an experienced surgeon and is time consuming. Nevertheless, 30% of surgeons in Germany who perform TKR have used navigation. It is still not known whether this new technique improves the longevity of TKR, however, and we therefore performed a meta-analysis to assess the results of this new health care technology.

Precision of computer-assisted core decompression drilling of the knee.

INTRODUCTION: Core decompression by exact drilling into the ischemic areas is the treatment of choice in early stages of osteonecrosis of the femoral condyle. Computer-aided surgery might enhance the precision of the drilling and lower the radiation exposure time of both staff and patients. The aim of this study was to evaluate the precision of the fluoroscopically based VectorVision-navigation system in an in vitro model. MATERIALS AND METHODS: Thirty sawbones were prepared with a defect filled up with a radiopaque gypsum sphere mimicking the osteonecrosis. 20 sawbones were drilled by guidance of an intraoperative navigation system VectorVision (BrainLAB, Munich, Germany). Ten sawbones were drilled by fluoroscopic control only. RESULTS: A statistically significant difference with a mean distance of 0.58 mm in the navigated group and 0.98 mm in the control group regarding the distance to the desired mid-point of the lesion could be stated. Significant difference was further found in the number of drilling corrections as well as radiation time needed. CONCLUSION: The fluoroscopic-based VectorVision-navigation system shows a high feasibility and precision of computer-guided drilling with simultaneously reduction of radiation time and therefore could be integrated into clinical routine.

Imageless navigation for insertion of the acetabular component in total hip arthroplasty: is it as accurate as CT-based navigation?

In a prospective randomised clinical study acetabular components were implanted either freehand (n = 30) or using CT-based (n = 30) or imageless navigation (n = 30). The position of the component was determined post-operatively on CT scans of the pelvis. Following conventional freehand placement of the acetabular component, only 14 of the 30 were within the safe zone as defined by Lewinnek et al (40 degrees inclination sd 10 degrees ; 15 degrees anteversion sd 10 degrees ). After computer-assisted navigation 25 of 30 acetabular components (CT-based) and 28 of 30 components (imageless) were positioned within this limit (overall p < 0.001). No significant differences were observed between CT-based and imageless navigation (p = 0.23); both showed a significant reduction in variation of the position of the acetabular component compared with conventional freehand arthroplasty (p < 0.001). The duration of the operation was increased by eight minutes with imageless and by 17 minutes with CT-based navigation. Imageless navigation proved as reliable as that using CT in positioning the acetabular component.

Eversion or subluxation of patella in soft tissue balancing of total knee arthroplasty? Results of a cadaver experiment.

Correct postoperative leg alignment and stability of total knee prosthesis over the full range of movement are critical factors for successful TKA. This is achieved by correct implantation of prosthesis and soft tissue handling. However, the surgical approach and how to displace the patella are still controversial. We have carried out a cadaver study looking at the effect of patella eversion or subluxation on limb axis alignment during balancing of the knee in three different standard surgical approaches; subvastus, midvastus, or medial parapatellar. For each approach, five knees were studied. Leg alignment was visualised by the Ci CT-free DePuy/BrainLAB navigation system. Using a navigation system alignment was determined in the AP axis in both extension and 90 flexion, with the patella everted as well as subluxated. Eversion of the patella gave a more valgus axis reading than subluxation in both extension 0.58 (SD: 0.03, range 0.54 -0.60 ) and 90 flexion 0.48 (SD: 0.11, range 0.38 -0.60 ). The effect was greatest using the medial paraptellar approach. Surgeons should be aware that everting the patella influences the AP alignment when soft tissue balancing in total knee replacement.

Two-year follow-up on joint stability and muscular function comparing rotating versus fixed bearing TKR.

Mobile and fixed bearing in total knee replacement are still discussed controversially. In a retrospective, matched-pair study, we investigated 40 patients with computer-assisted (BrainLAB) primary total knee replacement (PFC Sigma, DePuy) performed two years before. Twenty patients each received a mobile bearing and a fixed bearing. We compared Womac Score, Knee Society Score, postoperative ROM, fluoroscopic measurement of knee stability in flexion and extension and isokinetic muscle strength using a Biodex-3 dynamometer. Both groups showed similar results concerning WOMAC Score (total rotating bearing: 23.05; fixed bearing: 22.57), KSS (rotating bearing: 174.89; fixed bearing: 176.1). Isokinetic muscle force demonstrated statistically significant superior results for knee flexion in the rotating bearing group. Medio-lateral stability revealed statistically significant superior results for the rotating bearing compared to fixed bearing in extension (P>0.05). In flexion only lateral stability was superior (P>0.05). Two-year clinical follow-up after computer-assisted total knee replacement resulted in good clinical outcome with high patient satisfaction. Statistically significant better values for the rotating platform group were found for the medio-lateral stability in extension and the peak flexion torque.

[Soft tissue management in knees with varus deformity. Computer-assisted sequential medial ligament release]. / Weichteilmanagement bei der Varusgonarthrose. Der navigationsgestützte schrittweise mediale Bandrelease.

BACKGROUND: Knees with severe varus deformities and contractures of the medial and lateral collateral ligaments and the posterior capsule require special soft tissue management to gain a stable knee over the full range of movement. The introduction of navigation systems into knee surgery has now made precise measurement of the leg axis and gap size possible. METHODS: Ten knee joints received a computer-assisted total knee replacement (Ci navigation system DePuy) I-Orthopaedics, Munich). The change of the leg axis and the size of the mediolateral gaps were measured and documented when performing a standardized medial ligament release sequence. RESULTS: We found a significant effect after each release step regarding the change of the leg axis as well as the gap width (p<0.001). The highest effect was seen for the 6-cm capsule release in extension and the release of the medial collateral ligament in 90 degrees flexion. CONCLUSION: Implementation of computer-assisted navigation facilitates visualization and quantification of the effect of the sequential medial soft tissue release in total knee arthroplasty.

[What is the influence of the approach to intraoperative measurement of the knee joint on total knee arthroplasty? A navigation-controlled study on a cadaver knee]. / Beeinflusst der Zugangsweg die intraoperativ gemessene Beinachse in der Knieendoprothetik? Eine navigationsgestützte Studie am Kadaverknie.

Correct postoperative leg alignment and stability of the total knee prosthesis over the full range of movement is one critical factor for successful TKA. The anatomic approach is still the subject of controversy. The aim of our study was to elucidate the influence of the surgical approach on the ligament balancing and the anterioposterior limb axis.On five cadaver knees we studied the influence of the subvastus, midvastus, medial parapatellar, rectus snip, and tuberosity osteotomy approaches on the anterioposterior leg axis in extension and the rotation of the femoral component in flexion. Measurements were performed and documented by CT-free Ci-Navigation-System. Ligament tension was measured with a tensor device. We found that the subvastus approach leads to less widening of the medial compartment than all other approaches in extension. In 90 degrees flexion we found a similar influence. The consecutive release from subvastus to midvastus to medial parapatellar approach leads to a further opening of 0.5-1 degrees valgus in extension as well as in flexion. An everted patella amplifies this influence. The surgeon has to be aware of the impact on the ligament situation in regard to the anatomic approach when ligament balancing and soft tissue releases are carried out. Patella eversion should be avoided when managing soft tissues.