Platelet-rich plasma (PRP) as therapy for cartilage, tendon and muscle damage - German working group position statement.

PURPOSE: Platelet rich plasma (PRP) is widely used in orthopaedics, but is still heavily debated. Therefore, a survey among the German "Working Group for Clinical Tissue Regeneration" of the German Society of Orthopaedics and Traumatology was conducted to achieve a consensus about the current therapeutical potential of PRP. METHODS: A first survey (n = 65 experts, all orthopaedic/trauma surgeons) was conducted (n = 13 questions). Following, a second round (n = 40 experts) was conducted with 31 questions to achieve consensus in 5 categories: three most common indications, PRP application, future research areas. RESULTS: Therapeutic PRP application was regarded as useful (89%), possibly even more important in the future (90%). Most common indications were tendon pathologies (77%), osteoarthritis (OA) (68%), muscle injuries (57%) and cartilage damage (51%). Consensus was reached in 16/31 statements. The application of PRP for early knee OA (Kellgren-Lawrence grade II) was regarded as potentially useful, as well as for acute and chronic tendinopathies. For chronic lesions (cartilage, tendons), multiple injections (2-4) were seen preferable to singular injections. However, no sufficient data exists on the time interval between the injections. Standardization of PRP preparation, application, frequency, as well as determining the range of indication is strongly recommended. CONCLUSIONS: There is a need of further standardization of the PRP preparation methods, indication and application protocols for knee OA and other indications, which must be further evaluated in basic science studies and randomized controlled clinical trials. LEVEL OF EVIDENCE: Consensus of expert opinion, Level V.

[Seasonal distribution of clinical case codes (DOC study)]. / Saisonale Verteilung klinischer Kennzahlen (DOC-Study).

OBJECTIVES: The German diagnosis-related groups remuneration system (G-DRG) was implemented in 2004 and patient-related diagnoses and procedures lead to allocation to specific DRGs. This system includes several codes, such as case mix (CM), case mix index (CMI) and number of cases. Seasonal distribution of these codes as well as distribution of diagnoses and DRGs may lead to logistical consequences for clinical management. METHODS: From 2004 to 2013 all the main diagnoses and DRGs for inpatients were recorded. Monthly and seasonal distributions were analyzed using ANOVA. RESULTS: The average monthly number of cases was 265 ± 25 cases, the average CM was 388.50 ± 51.75 and the average CMI was 1.46 ± 0.15 with no significant seasonal differences (p > 0.1). Concussion was the most frequently occurring main diagnosis (3739 cases) followed by fractures of the humeral head (699). Significant distribution differences could be shown for humeral head fractures in monthly (p = 0.018) and seasonal comparisons (p = 0.006) with a maximum in winter. Radius (p = 0.01) and ankle fractures (p ≤ 0.001) also occurred most frequently in winter. Non-bony lesions of the shoulder were significantly less in spring (p = 0.04). The DRGs showed no evidence of a monthly or seasonal clustering (p > 0.1). CONCLUSION: The significant clustering of injuries in specific months and seasons should lead to logistic consequences (e.g. operating room slots, availability of nursing and anesthesia staff). For a needs assessment the analysis of main diagnoses is more appropriate than DRGs.

Improved accuracy of K-wire positioning into the glenoid vault by intraoperative 3D image intensifier-based navigation for the glenoid component in shoulder arthroplasty.

INTRODUCTION: This article aimed to show that navigation, based on an intraoperative mobile 3D image intensifier, can improve the accuracy of central K-wire placement into the glenoid vault for glenoid component. HYPOTHESIS: The navigated k-wire placement is more accurate and shows a smaller deviation angle to the standard centerline compared to the classical "free hand technic". METHODS: In 34 fresh frozen sheep scapulae, 17 K-wire placements using the navigation (group 1) were compared with 17 using standard "face plane technique" (group 2). The relation to glenoid standard and alternative centerlines (CL) and the position within the glenoid vault were analyzed. RESULTS: In groups 1 and 2 the angle between the K-wire and standard CL was 2.2° and 4.7°, respectively (P=0.01). The angle between the K-wire and alternative CL was 14.4° for group 1 and 17.2° for group 2 (P=0.02). More navigated K-wire positions were identified within a 5mm corridor along the glenoid vault CL (52 vs. 39; P=0.004). DISCUSSION: Intraoperative 3D image intensifier-based navigation was more accurate and precise than standard K-wire placement. TYPE OF STUDY AND LEVEL OF PROOF: Basic science study, evidence level III.

3D ultrasound biomicroscopy for assessment of cartilage repair tissue: volumetric characterisation and correlation to established classification systems.

Objective and sensitive assessment of cartilage repair outcomes lacks suitable methods. This study investigated the feasibility of 3D ultrasound biomicroscopy (UBM) to quantify cartilage repair outcomes volumetrically and their correlation with established classification systems. 32 sheep underwent bilateral treatment of a focal cartilage defect. One or two years post-operatively the repair outcomes were assessed and scored macroscopically (Outerbridge, ICRS-CRA), by magnetic resonance imaging (MRI, MOCART), and histopathology (O'Driscoll, ICRS-I and ICRS-II). The UBM data were acquired after MRI and used to reconstruct the shape of the initial cartilage layer, enabling the estimation of the initial cartilage thickness and defect volume as well as volumetric parameters for defect filling, repair tissue, bone loss and bone overgrowth. The quantification of the repair outcomes revealed high variations in the initial thickness of the cartilage layer, indicating the need for cartilage thickness estimation before creating a defect. Furthermore, highly significant correlations were found for the defect filling estimated from UBM to the established classification systems. 3D visualisation of the repair regions showed highly variable morphology within single samples. This raises the question as to whether macroscopic, MRI and histopathological scoring provide sufficient reliability. The biases of the individual methods will be discussed within this context. UBM was shown to be a feasible tool to evaluate cartilage repair outcomes, whereby the most important objective parameter is the defect filling. Translation of UBM into arthroscopic or transcutaneous ultrasound examinations would allow non-destructive and objective follow-up of individual patients and better comparison between the results of clinical trials.

[Multiplanar reconstruction with mobile 3D image intensifier. Surgical treatment of proximal humerus fractures]. / Multiplanare Rekonstruktion mit mobilem 3D-Bildwandler. Operative Versorgung proximaler Humerusfrakturen.

PURPOSE: The aim of this study was to analyze the applicability and advantages of the intraoperative use of a mobile 3D C-arm with multiplanar imaging for surgery of acute proximal humerus fractures. MATERIALS AND METHODS: In this study 20 patients (11 female, 9 male, median age 70 years, range 35-91 years) with dislocated proximal humerus fractures (6 with 2 segments, 10 with 3 segments and 4 with 4 segments) were included. Preoperatively 3D scanning was performed and a reevaluation of the fracture in comparison to the plain radiographs was performed. After operative treatment another scan was performed to evaluate technical complications. RESULTS: In comparison to the multiplanar reconstructions fracture morphology could not be correctly detected in 5 out of the 20 cases with plain radiographs. The preoperative image quality of the multiplanar reconstructions showed a significantly better assessment in comparison to the image quality with osteosynthesis (p < 0.05). The screws had to be replaced in 5 of the 20 patients. CONCLUSION: Intraoperative 3D imaging with mobile image intensifier enables an accurate analysis of fracture morphology. Furthermore a quasi real time preoperative planning, evaluation of reduction and implant position with immediate operative relevance can be realized.

[Is distal femoral replacement an adequate therapeutic option after complex fractures of the distal femur?]. / Ist der distale Femurersatz als extremitätenerhaltendes Verfahren nach komplexen Frakturen am distalen Femur geeignet?

BACKGROUND: Modular distal femur replacements originally were developed for reconstructing a full weight-bearing and functional extremity after resection of primary bone tumours with large bony defects located in proximity to joints. The aim of this study was to examine the use of the modular distal femur replacements for complex fractures and severe post-traumatic sequelae of the distal femur in context to comparable studies. PATIENTS AND METHODS: Fourteen patients with complex fractures or post-traumatic sequelae and extensive bone defects requiring distal femur replacement were analysed retrospectively. Median age of the patients at the time of distal femoral replacement was 77 years and median follow-up interval was 27 months. Median follow-up was 27.0 (IQB 13.5-37.5) months (range 10-49 months). RESULTS: The indication for distal femur replacement was a periprosthetic fracture in three cases. Three further periprosthetic fractures were treated with a megaendoprosthesis after failure of osteosynthesis. In eight patients a megaendoprosthesis was implanted due to complications following ostheosynthesis for distal femoral fractures. Distal femoral arthroplasty was performed as a two-stage procedure in five patients with implant-associated infections. A lateral approach was used in six patients and a medial arthrotomy was conducted in eight patients. The median Knee Society score (KSS) improved significantly from 20.0 (IQB 7.5-30.0) points preoperatively to 80.0 (IQB 62.3-89.0) points at follow-up (p < 0.001). Complications requiring surgical intervention were documented in seven of 14 patients (50 %). In two patients wound-healing disorders and superficial infections necessitated surgery. In one patient a rupture of the patellar tendon was diagnosed. This patient subsequently also sustained a periprosthetic fracture. Another patient developed early aseptic loosening of the femoral component. The most common complication was a periprosthetic fracture in four patients. Three patients died for reasons not related to distal femoral replacement. CONCLUSION: Distal femoral replacement is an important option in reconstituting a full weight-bearing and functional lower extremity after complex fractures and post-traumatic sequelae with massive bone destruction. Particularly elderly patients regain ambulatory ability in the vast majority of cases. The relatively high complication rate demands very thorough preoperative planning as well as prompt allocation of extensive surgical procedures in the case of an adverse event.

[Clinical and radiological mid-term results after autologous osteochondral transplantation under consideration of quality of life]. / Mittelfristige klinische und radiologische Ergebnisse nach autologer osteochondraler Transplantation unter Berücksichtigung der Lebensqualität.

BACKGROUND: Treatment of full-thickness cartilage defects remains a challenge in musculoskeletal surgery. Autologous osteochondral transplantation represents a possible solution for the repair of affected areas. However, some problems like degenerative changes of the transplanted cylinders and the surrounding cartilage or lack of cylinder integration to the surrounding cartilage arise with this method. Thus mid-term results respecting the quality of life are useful for assessment of the method. PATIENTS/MATERIAL AND METHODS: We investigated 22 patients with a mean follow-up of 88 ± 14.5 months after autologous osteochondral transplantation due to a full-thickness cartilage defect of the medial femoral condyle. Beside clinical scores we assessed at follow-up the quality of life using the SF-36 health survey and the EQ-5D. Furthermore, radiological changes were detected and MRI was performed in 21 patients. A control group of 19 patients, treated with microfracture, was matched in terms of BMI, gender and age. Exclusion criteria for this group were tibial kissing lesion, ligament instability, arthrosis and malalignment. RESULTS: In a longitudinal comparison with results 13.5 months after operation, no difference in Lysholm score was found. In plain radiographs higher degrees of arthritic changes in the medial compartment compared to the unaffected knee were observed. MRI revealed a mean modified MOCART score of 41.2 ± 7.7 for the OAT group and of 39.4 ± 16.1 for the microfracture group, without being significant. For OAT patients all cylinders showed an osseous integration. However, cylinder oedema was found in 9 patients. Those patients had a higher intensity of pain on a visual analogue scale. Quality of life was better for OAT patients in the physical scale of SF-36, but not in the mental scale. CONCLUSION: Autologous osteochondral transplantation has an unaltered significance in treating full-thickness cartilage defects and leads to satisfying mid-term results. The development of early arthritic changes might not be preventable by this method. Oedema of the transplanted cylinders is attended by higher pain intensity and might be an indirect sign of cartilage degeneration.

[Total knee arthroplasty in post-traumatic osteoarthritis]. / Knieendoprothetik bei posttraumatischer Arthrose.

BACKGROUND: This study aims to analyse the outcome and the complications after total knee arthroplasty in post-traumatic osteoarthritis in comparison to TKA in patients with degenerative osteoarthritis. PATIENTS AND METHODS: In a period of six years 43 patients with a post-traumatic osteoarthritis were treated with a total knee arthroplasty (group PT). 38 (88 %) patients (age median 55 years, 22 female, 16 male) were investigated clinically and radiologically after an average follow-up time of 2.7 years. The OKS (Oxford Knee Score, max. 48 points), the Knee Society Scores "function" (max. 100 points) and "knee" (max. 100 points) as well as the visual analogue scale (VAS, 0 to 10 points) were recorded preoperatively and at follow-up. For comparison we chose a matched-pair selection of patients with degenerative osteoarthritis and TKA (group DO, age median 63 years, 22 female, 16 male). For statistical analysis we used common parametric tests (Wilcoxon and U test) and a level of significance of 0.05. RESULTS: In 19 patients (50 %) of the group PT the osteoarthritis was caused by a bone injury. Furthermore in 19 patients a meniscal and/or ligamentous injury led to osteoarthritis. Out of all patients of group PT, 10 patients showed a preoperative valgus malalignment higher than 10°. KSS knee and KSS function added up to 76.9 and 84.9 points. So they are significantly less than in the matched group (DO, knee: 86.1; function: 94.4). Similarly, the OKS is significantly less in group PT after follow-up (PT: 32.3; DO: 38.4, p ≤ 0.05) although the preoperative values are equal in both groups. The VAS value decreased significantly in both groups. Initial level of pain was significantly higher in the group DO compared to the group PT. Patients with osteoarthritis after trauma showed complications in 17 cases (^ = 44.7 %) that led to 28 revision operations (^ = 0.7 operations per knee). The group with valgus malalignment had a revision rate of 1.4 operations per knee. In the group DO 8 complications occurred (^ = 21,1 %) that led to 11 revision operations (^=0.3 per knee). The deviation from the "ideal" leg axis could be reduced from 3.8° varus to 1.7° varus in the group DO and from 1.3° valgus auf 1.2° valgus in the group PT. Patients with a preoperative valgus deviation > 10° were reduced from 13.6° (± 3.9°) valgus to 0.5° (± 9.2°) varus. CONCLUSION: Patients after TKA because of post-traumatic osteoarthritis show worse results concerning function and condition compared to patients with degenerative osteoarthritis. Heterogeneous pathogenesis and high rates of revision operations underline the complexity of this group of patients. The treatment has to be adjusted to the patient's requirements as well to the pathoanatomy.

[Seasonal distribution of diagnoses and DRG in trauma surgery]. / Saisonale Verteilung von Diagnosen und DRG in der Unfallchirurgie.

BACKGROUND: Recording DRGs and diagnoses allows their distribution to be shown over the course of the year. Thus, cumulative seasonal occurrence of diseases can be detected. PATIENTS AND METHODS: From 2004 to 2010 we recorded 22,293 main diagnoses and DRGs at the clinic for trauma surgery. Injuries with the same localization and treatment were pooled. RESULTS: The most frequent injuries were concussion, followed by spinal and lower leg fractures. They showed no seasonal accumulation. Proximal fractures of the humerus occurred approx. 25% more often in winter and ankle fractures about 33% more frequently. The diagnosis of osteoarthritis of the knee is twice as high in the winter as in the summer. CONCLUSION: It has to be verified if logistic conclusions of these results can lead to more efficiency in a hospital. The underlying analysis is applicable for every hospital and poses a valid controlling tool.

[Acute and chronic instability of the elbow joint]. / Akute und chronische Instabilitäten des Ellenbogengelenks.

Successful treatment of elbow instability is aided by fundamental biomechanical understanding. This allows for clinical instability to be traced back to structural injuries, which can be addressed with targeted therapy. Acute instability of the elbow joint after frequent posterolateral dislocations tends to affect the radial ligamentous complex. In addition to simple ligamentous injuries, fractures can also contribute to elbow instability; comminuted fractures of the radial head often correlate with a rupture of the ulnar collateral ligament. Improperly healed acute injuries can result in chronic instability. However, recurrent microtrauma such as that seen in throwing athletes can also lead to changes in joint laxity. Conservative therapy of simple elbow dislocation usually leads to satisfactory results. In isolated cases, chronic lateral instability may result that requires operative stabilization. Recently, chronic posterolateral instability has been seen as the primary underlying pathology in unstable elbows. Chronic medial instability is also a problem for active athletes and may even lead to inability to participate in athletics. Conservative therapy should be the primary course of treatment. Surgical treatment may be indicated if conservative measures fail, if an athlete desires additional treatment, or in cases of high-grade medial instability. In this case, a rehabilitation period of up to one year should be expected.

A novel MSC-seeded triphasic construct for the repair of osteochondral defects.

Mesenchymal stem cells (MSC) are increasingly replacing chondrocytes in tissue engineering based research for treatment of osteochondral defects. The aim of this work was to determine whether repair of critical-size chronic osteochondral defects in an ovine model using MSC-seeded triphasic constructs would show results comparable to osteochondral autografting (OATS). Triphasic implants were engineered using a beta-tricalcium phosphate osseous phase, an intermediate activated plasma phase, and a collagen I hydrogel chondral phase. Autologous MSCs were used to seed the implants, with chondrogenic predifferentiation of the cells used in the cartilage phase. Osteochondral defects of 4.0 mm diameter were created bilaterally in ovine knees (n = 10). Six weeks later, half of the lesions were treated with OATS and half with triphasic constructs. The knees were dissected at 6 or 12 months. With the chosen study design we were not able to demonstrate significant differences between the histological scores of both groups. Subcategory analysis of O'Driscoll scores showed superior cartilage bonding in the 6-month triphasic group compared to the autograft group. The 12-month autograft group showed superior cartilage matrix morphology compared to the 12-month triphasic group. Macroscopic and biomechanical analysis showed no significant differences at 12 months. Autologous MSC-seeded triphasic implants showed comparable repair quality to osteochondral autografts in terms of histology and biomechanical testing.

Mesenchymal stem cells in cartilage repair: state of the art and methods to monitor cell growth, differentiation and cartilage regeneration.

Degenerative joint diseases caused by rheumatism, joint dysplasia or traumata are particularly widespread in countries with high life expectation. Although there is no absolutely convincing cure available so far, hyaline cartilage and bone defects resulting from joint destruction can be treated today by appropriate transplantations. Recently, procedures were developed based on autologous chondrocytes from intact joint areas. The chondrocytes are expanded in cell culture and subsequently transplanted into the defect areas of the affected joints. However, these autologous chondrocytes are characterized by low expansion capacity and the synthesis of extracellular matrix of poor functionality and quality. An alternative approach is the use of adult mesenchymal stem cells (MSCs). These cells effectively expand in 2D culture and have the potential to differentiate into various cell types, including chondrocytes. Furthermore, they have the ability to synthesize extracellular matrix with properties mimicking closely the healthy hyaline joint cartilage. Beside a more general survey of the architecture of hyaline cartilage, its composition and the pathological processes of joint diseases, we will describe here which advances were achieved recently regarding the development of closed, aseptic bioreactors for the production of autologous grafts for cartilage regeneration based on MSCs. Additionally, a novel mathematical model will be presented that supports the understanding of the growth and differentiation of MSCs. It will be particularly emphasized that such models are helpful to explain the well-known fact that MSCs exhibit improved growth properties under reduced oxygen pressure and limited supply with nutrients. Finally, it will be comprehensively shown how different analytical methods can be used to characterize MSCs on different levels. Besides discussing methods for non-invasive monitoring and tracking of the cells and the determination of their elastic properties, mass spectrometric methods to evaluate the lipid compositions of cells will be highlighted.

[Intramedullary nailing of proximal tibial fractures. Complications and risk factors]. / Marknagelosteosynthese proximaler Tibiafrakturen. Komplikationen und Risikofaktoren.

INTRODUCTION: We performed a consecutive study on patients with proximal tibial fractures without joint participation to determine the early clinical and radiological outcome. PATIENTS: From January 2000 to December 2005, 22 fractures of the proximal and proximal diaphyseal tibia without joint participation were operated on using the new tibia nail. A total of 18 patients (82%) completed full follow-up after 6 weeks and 3 and 6 months. RESULTS: Two primary and one secondary malalignment were observed Two of them were initially polytraumatised. Furthermore, two patients developed a delayed union, and one non-union occurred. Risk factors for limited bony consolidation were smoking and an open fracture. Screw or nail breakage did not occur, and no infection was observed.

Perilesional changes of focal osteochondral defects in an ovine model and their relevance to human osteochondral injuries.

Perilesional changes of chronic focal osteochondral defects were assessed in the knees of 23 sheep. An osteochondral defect was created in the main load-bearing region of the medial condyle of the knees in a controlled, standardised manner. The perilesional cartilage was evaluated macroscopically and biopsies were taken at the time of production of the defect (T0), during a second operation one month later (T1), and after killing animals at three (T3; n = 8), four (T4; n = 8), and seven (T7; n = 8) months. All the samples were histologically assessed by the International Cartilage Repair Society grading system and Mankin histological scores. Biopsies were taken from human patients (n = 10) with chronic articular cartilage lesions and compared with the ovine specimens. The ovine perilesional cartilage presented with macroscopic and histological signs of degeneration. At T1 the International Cartilage Repair Society 'Subchondral Bone' score decreased from a mean of 3.0 (SD 0) to a mean of 1.9 (SD 0.3) and the 'Matrix' score from a mean of 3.0 (SD 0) to a mean of 2.5 (SD 0.5). This progressed further at T3, with the International Cartilage Repair Society 'Surface' grading, the 'Matrix' grading, 'Cell Distribution' and 'Cell Viability' grading further decreasing and the Mankin score rising from a mean of 1.3 (SD 1.4) to a mean of 5.1 (SD 1.6). Human biopsies achieved Mankin grading of a mean of 4.2 (SD 1.6) and were comparable with the ovine histology at T1 and T3. The perilesional cartilage in the animal model became chronic at one month and its histological appearance may be considered comparable with that seen in human osteochondral defects after trauma.

[Lesser tuberosity avulsion in combination with multifragment fracture of the greater tuberosity. A rare entity at the proximal humerus]. / Kombinierte Tuberculum-minus-Avulsion mit Mehrfragmentfraktur des Tuberculum majus. Eine Rarität am proximalen Humerus.

Isolated fractures of the greater tuberosity represent 14-21% of all proximal humeral fractures. Lesser tuberosity fractures have mainly been mentioned in case reports. We report a rare case of a combination of a lesser tuberosity avulsion with a multifragment fracture of the greater tuberosity of the proximal humerus in a young man. The injury mechanism might be a complex interaction between abduction and external rotation with impaction and shearing against the glenoid and acromion.

[One- and two-stage procedure for revision after failure of anterior cruciate ligament reconstruction]. / Ein- und zweizeitiges Vorgehen bei Revisionschirurgie des vorderen Kreuzbandes.

AIM: Most surgeons favour a one-stage procedure for ACL revision surgery. Tunnel widening, limited range of motion or existent hardware can make a two-stage procedure necessary. Studies evaluating the results between both procedures are still lacking. Thus, we performed a prospective preliminary study comparing early results after one- and two-stage procedures for ACL revision reconstruction. METHOD: Between 1/2005 and 1/2006 21 patients were operated on for ACL revision. The follow-up period of the 4 women and 16 men was 12 months. One patient was excluded due to a juvenile osteoporosis. Median age was 34 years. All patients had a subjective instability, including 11 patients (55%) with a traumatic rerupture. The indication for a two-stage procedure depended on tunnel widening under consideration of tunnel placement, disturbing existing hardware and extension deficits. Eleven patients received a one-stage procedure while 9 patients were operated in a two-stage process. Seven received autogenous bone grafting. RESULTS: The preoperative tunnel diameter was for one-stage revisions (OS) femoral 7.9 +/- 1.8 mm and tibial 8.8 +/- 2.2 mm. For the two-stage (TS) procedure mean femoral tunnel was preoperatively 10.1 +/- 1.4 mm and tibial 12.1 +/- 1.4 mm. Femoral tunnel placement after revision (OS/TS) yielded a mean angle in anteroposterior view of 28.7 degrees /26.9 degrees and in the sagittal view most tunnels were placed in the dorsal quadrant. Tibial placement was in the sagittal view at 46.1%/46.9% in the anteroposterior direction and for mediolateral direction in the a. p. view at 44.2%/44.5%. Results for Lysholm score were 85.7/83.9 and for IKDC 73.6/76.4. The anterior tibial translation compared to the healthy side was 1.5 mm/1.8 mm. In one leg jumping patients obtained a distance of 83 %/86% of the healthy side and stated their pain on a VAS to be as low as 1.9/1.4 points. Both groups had similar ranges of motion as well. CONCLUSION: The success of ACL revision surgery crucially depends on preoperative planning and analysis. No functional or radiological differences could be observed between one- and two-stage procedures. Although the one-stage procedure might be favourable because of faster convalescence and shorter work incapacity, it should not be enforced at the price of an insufficient ACL.

[Revision possibilities after failed unicompartmental knee arthroplasty--an analysis of 116 revisions]. / Revisionsmöglichkeiten nach Problemen mit unikondylären Endoprothesen--Eine Analyse von 116 Operationen.

AIM: A major advantage of the unicompartmental knee arthroplasty (UKA) is the quick rehabilitation, small traumatisation of tissue and the mostly uncomplicated revision to a total knee arthroplasty. The aim of the study is to examine whether the conversion to the total endoprosthesis, as is frequently is recommended at present in cases of defect of the sleigh system, is always necessary or whether a revision can have good chances of success with use of the unicondylar system under certain conditions. METHOD: 116 revisions were studied after unicompartmental knee arthroplasty at the first appearance of problems and during the follow-up of 45 months (range: 10-86 months) using the Knee Society Score and analyses of the various additional procedures as well as the anterior cruciate ligament substitute, the correction of slope etc. Revisions, with exchange of components or a conversion to a total arthroplasty, were included. RESULTS: In 60.3 % of all cases a revision could be performed within the unicompartmental knee system, with a mean score of 167.4 (range: 144-173). The outcome score corresponded to the outcome of primary UKA implantations and to conversion operations to total endoprosthesis in the literature (p < 0.05 Wilcoxon test). CONCLUSION: Under critical contemplation of the low case number and this short- to medium-term examination, individual revision solutions seem to have their entitlement within the unicondylar system as also do conversion operations to the TKA. Long-term results and larger case numbers are absolutely necessary prior to further judgment.

[Differentiated therapy in necrotizing fasciitis of three extremities]. / Differenzierte Therapie bei nekrotisierender Fasziitis dreier Extremitäten.

AIM: Here we present the clinical symptomatology of and therapy for necrotizing fasciitis. METHOD: The case of a 35-year-old female patient with sustaining fractures of the 5 (th) and 10 (th) thoracic vertebrae and a pulmonary contusion and without any skin lesions is presented. RESULTS: Conventional x-rays and computed tomography revealed stable spine fractures not necessitating surgical intervention. Fifteen days after the accident the patient developed septic conditions. An interdisciplinary search (surgical, neurological, urological, internal medicine) for the septic focus first remained negative. After demarcation of necrotic skin areas at the upper left arm, bilateral necrotizing fasciitis was diagnosed at both thighs and at the lower left leg, necessitating continuous optimisation of the therapeutic strategy. CONCLUSION: Local aggressive surgical therapy in combination with systemic antibiotic administration is the therapy of choice in treatment of the necrotizing fasciitis. It should be performed according to the principle "life before limb". In the presented case the patient recovered and good functional results could be achieved.