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The role of joint replacement in the treatment of osteoarthritis of the thumb carpometacarpal joint is a subject of considerable controversy in the current literature. In German-speaking countries this technique is used much less frequently than resection procedures. Aseptic loosening of the prosthesis is believed to be the major cause of the high failure rates reported for cemented and uncemented types of implants. In this study the different implant designs were evaluated on the basis of the results reported in the international literature. There are only a few studies that cover relatively long follow-up periods and provide convincing results for thumb carpometacarpal joint prostheses in terms of implant survival and function. Aseptic loosening is reported to be the major cause with failure rates of 50 % or more. Although a Norwegian study reported high 5 and 10-year survival rates for various thumb carpometacarpal joint prostheses according to the Norwegian arthroplasty registry, it did not recommend the widespread use of thumb carpometacarpal joint replacement at the present time. In our opinion, joint replacement may be considered as a possible treatment option for advanced osteoarthritis of the thumb carpometacarpal joint but it should not always be recommended because long-term results are inconsistent and similar functional outcomes have been reported for alternative surgical techniques, such as resection arthroplasty.

The German Arthroplasty Registry (EPRD) was founded in 2010 and has been in full operation since 2014. Previous attempts at a systematic data collection of elective and non-elective knee and hip replacement in Germany failed mainly because of the long-term lack of funding. The EPRD is an interdisciplinary collaborative partnership between the German Association of Orthopedics and Orthopedic Surgery (DGOOC), all implant manufacturers of the German Medical Technology Association (BVMed), health insurers (AOK and the Association of Additional Healthcare Insurance) and hospitals (German Hospital Federation). As part of this cooperation a worldwide unique implant database has been set up, which includes all relevant components and a detailed description of implant specifications. This implant library enables a detailed evaluation of implant survival, revision rates and possible inferior implant performance of knee and hip replacements in Germany. At the end of 2015 the EPRD encompassed over 200,000 registered operations. Due to the high number of hip and knee arthroplasties in Germany with many different implants from different manufacturers there will be a rapid growth of data that are available for a national and also international comparison of the results.

Ziele der Arbeit waren die mittelfristigen klinisch-funktionellen und radiologischen Ergebnisse des Cranialsockelsystems zu analysieren. In dieser Studie wurden die Daten zu 92 Cranialpfannen erhoben und ausgewertet. Es konnte während des Beobachtungszeitraumes in fünf Fällen ein Versagen der Cranialpfanne verzeichnet werden. Zusammenfassend konnten wir in dieser monozentrischen, retrospektiven Studie mit einem Nachuntersuchungsraum von 4,2 Jahren relativ gute klinische Ergebnisse bzgl. Revisionsraten und Überleben aufzeigen. Jedoch steht eine kritische Beurteilung der Langzeitergebnisse noch aus. A total of 92 cup revisions using the cranial socket system were clinically and radiologically analyzed with an average follow-up of 4.2 years. Defects were classified according to D'Antonio. There were 39 type II, 38 type III, and 15 type IV defects. The Harris Hip Score increased from 41.1 preoperatively to 62.3 points postoperatively. Six patients had recurrent hip dislocation requiring replacement of the inlay. In five cases of aseptic loosening, the acetabular component had to be revised. With revision of the acetabular component as an endpoint, implant survival was 94,6% after an average of 4.2 years.

The cumulative incidence of periprosthetic fractures around the knee is increasing further because of an extended indication for knee replacement, previous revision arthroplasty, rising life expectancy and comorbidities.The relevance of local parameters such as malalignment, osseous defects, neighbouring implants, aseptic loosening and low-grade infections may sometimes be hidden behind the manifestation of a traumatic fracture. A differentiated diagnostic approach before the treatment of a periprosthetic fracture is of paramount importance, while the physician in-charge should also have particular expertise in fracture treatment and in advanced techniques of revision endoprosthetics. The following work gives an overview of this topic.Valid classifications are available for categorising periprosthetic fractures of the femur, the tibia and the patella respectively, which are helpful for the selection of treatment.With the wide-ranging modern treatment portfolio bearing in mind the substantial rate of complications and the heterogeneous functional outcome, the adequate analysis of fracture aetiology and the corresponding transformation into an individualised treatment concept offer the chance of an acceptable functional restoration of the patient at early full weight-bearing and prolonged implant survival. The management of complications is crucial to the final outcome.

High-carbon (HC) alloys for hip arthroplasties were preferred to low-carbon (LC) alloys for a long time because of their structurally hard carbide content. We opted for an LC alloy in 1994, because we expected it to be subject to less wear on account of its more homogeneous structure. Prompted by early complications not seen with ceramic-on-polyethylene mating surfaces, LC metal-on-metal articulations were, however, given up by us in early 1999. A series of implants retrieved after 11 to 17 years was now studied to establish the actual amount of wear. Potential tissue reactions associated with hypersensitivity were also evaluated histologically and correlated with the measured wear and the amount of metal particles in capsular tissue.Ten patients with LC metal-on-metal hip implants were the subjects of analyses after a mean follow-up time of 13.9 years. They underwent revision surgery because of osteolysis, cup loosening without dislocation, late infection in 1 patient and pain. The implant positions at the time of retrieval were the same as on the postoperative radiographs. Wear was determined in keeping with ISO 14242-2 and by SEM. In addition, periprosthetic tissue including the joint capsule and interface membranes were obtained for histological analysis. The amount of metal particles and the extent of lymphocyte infiltration were determined with the method described by Willert et al. Tissue alterations were evaluated histologically for signs of ALVAL using the method of Campbell et al. and correlated with the amount of wear and metal particles.The mean maximum linear wear rate was found to be 1.6 (1.0-2.1) µm/year. Our data also showed a mean rate of 0.32 mm³/year (range, 0.22-0.47 mm³/year). This is equivalent to an annual metal release of 2.7 (1.9-3.9) mg/year. No corrosion or corrosion products were present on the ball heads and their taper. All mating surfaces studied by SEM showed signs of abrasion. Sporadically, additional abrasions in the submicrometer range were detected on the ball head surfaces. These were caused by corundum particles detached from the blasted implant surfaces and interpreted as third-body wear below the level of quantification. Signs of impingement were absent. Histologically, metal wear particles of variable amount were detected in all cases. In 4 of them solid corrosion products were present in the tissue. The ALVAL scores were 5 to 10 (moderate to high), but did not correlate with the measured wear and the amount of metal particles.The wear of LC articulations found after years of implant survival was very low. In fact, it was lower than the data reported for HC articulations and would permit implants to function for decades in engineering terms. However, their survival is limited by tissue alterations associated with hypersensitivity. These tissue alterations may contribute to implant loosening as also reported for HC articulations. They are apparently not related to the actual amount of wear and may reflect adaptive immunological processes.

Because of anatomical variations total hip arthroplasty (THA) can be demanding in patients with osteoarthritis secondary to hip dysplasia.Depending on the degree of bony deformation, hip dislocation and soft tissue alteration numerous treatment strategies are available. This review describes current approaches that address frequent deformities.Review of relevant clinical studies, meta-analyses, and presentation of our own approach.Pre-operative planning (based on a thorough clinical and radiographic examination) is essential. Acetabular reconstruction close to the primary acetabulum should always be intended. Roof augmentation and/or cup medialization can support stable bony implant fixation. Subtrochanteric shortening osteotomy of the femur is a demanding but reliable technique that avoids nerve damage in cases where inappropriate lengthening would be necessary (i.e., high riding dislocation).Although the post-operative complication rate is elevated after THA for dysplastic hips compared with primary osteoarthritis, the overall functional results and implant survival are comparable.

Objective: The aim of this cohort study in partially edentulous subjects with treated for generalized chronic (GCP) and generalized aggressive periodontitis (GAgP) was the evaluation of mucositis, peri-implantitis as well as the success and survival rate of implants with TiUnite® surface. Materials and Methods: The oral rehabilitation of 24 subjects treated for generalized chronic periodontitis (GCP) and 5 subjects with treated for generalized aggressive periodontitis (GAgP) was performed using 130 TiUnite®-implants. The Baseline was examined 2 to 4 weeks before non-retainable teeth were extracted. A second examination followed 3 weeks after insertion of the final abutments. Further examinations to record clinical parameters were performed during a quarterly recall program over a test period of 2 – 8 years. The marginal bone loss was radiologically measured at baseline, after insertion of super-structure as well as 1, 3, 5 and 8 years later. Results: The results show an implant survival rate of 97.1 % in GCP patients and 96.2 % for GAgP patients. The success rate of implants in subjects with generalized chronic periodontitis was 77.9 % and 38.5 % for GAgP subjects. In GAgP subjects, peri-implant mucositis was presented in 28.0 % and peri-implantitis in 32.0 % of the implants. In GCP Patients 7.7 % of the implants showed a peri-implant mucositis and 12.5 % a periimplantitis. GAgP subjects had a 6 time greater risk of implant failure, a ≈ 4.7 time greater risk of peri-implant mucositis and a ≈ 3.3 times greater risk of peri-implantitis.The mean marginal bone loss was 2.19 mm for both groups. Implants in GAP subjects had a 3 times higher marginal bone loss (4.89 mm) than GCP subjects. Conclusion: The results indicate that TiUnite® implants ensure the oral rehabilitation of partially edentulous patients with treated GAgP and GCP over a test period of 2 – 8 years. Patients with GAgP are more susceptible to peri-implant mucositis and peri-implantitis than patients with GCP. In addition, patients with GAgP have also demonstrated lower survival and success rates., Hintergrund: Ziel dieser Kohortenstudie bei teilbezahnten Patienten mit behandelter generalisierter chronischer und aggressiver Parodontitis ist die Evaluation einer Mukositis, Periimplantitis, Erfolgs- und Überlebensrate an Implantaten mit TiUnite®-Oberfläche. Material und Methoden: 24 Patienten mit behandelter generalisierter chronischer Paro-dontitis (GCP) und 5 Patienten mit behandelter generalisierter aggressiver Parodontitis (GAP) wurden mittels 130 osseointegrierten TiUnite®-Implantaten oral rehabilitiert. Die Baseline-Untersuchung wurde 2 – 4 Wochen vor Extraktion der nichterhaltungswürdigen Zähne durchgeführt. 3 Wochen nach Eingliederung der definitiven Abutments erfolgte eine weitere Kontrolle. Die klinischen Parameter wurden alle 3 Monate über einen Untersuchungszeitraum von 2 – 8 Jahren evaluiert. Röntgenaufnahmen wurden zur Baseline-Untersuchung, nach Insertion der Supra-konstruktion, sowie 1, 3, 5 und 8 Jahre danach durchgeführt. Ergebnisse: Die Ergebnisse zeigten eine Überlebensrate der Implantate von 97,1 % für GCP-Patienten und 96,2 % für GAP-Patienten. Die Erfolgsrate betrug 77,9 % bei GCP- und 38,5 % bei GAP-Implantaten. Bei GAP-Patienten zeigten 28,0 % der Implantate eine Mukositis und 32,0 % eine Periimplantitis. Bei GCP-Patienten wiesen 7,7 % der Implantate eine Mukositis und 12,5 % eine Periimplantitis auf. Implantate in GAP-Patienten zeigten ein ca. 6-fach höheres Risiko für einen Implantatmisserfolg, ein rund 4,7-mal höheres Risiko für eine Mukositis und ein etwa 3,3-fach höheres Risiko für eine Periimplantitis. Implantate in GAP Patienten wiesen einen annähernd 3-mal stärkeren Knochenabbau (4,89 mm) auf als in der GCP-Gruppe (1,38 mm). Fazit: Dentale Implantate mit TiUnite®-Oberfläche gewährleisten die orale Rehabilitation von teilbezahnten Patienten mit parodontalen Vorerkrankungen über einen Untersuchungs-zeitraum von 2 – 8 Jahren. Allerdings sind Patienten mit behandelter generalisierter aggressiver Parodontitis anfälliger für Mukositis und Peri-implantitis und weisen an Implantaten höhere Verlust- und Misserfolgsraten auf.

The burden of revision of the 210,000 total hip and the 146,000 total knee arthroplasties performed in Germany every year is 10.9% and 7.9%, respectively. Since the probability of revisions could be cut in half by the implementation of a national joint registry in Sweden, several other countries have also established national joint registries. Nevertheless, these registries were not able to detect the failure of some implant systems, which resulted in thousands of patients who had received implants being recalled later on.We aimed to identify the methods that are currently used for statistical analyses in joint registries and which could be used to implement an early warning system.We analyzed the available reports of national joint registries regarding the methods used for the early detection of implants that perform less efficiently than expected. The methods identified are described and evaluated if they are suitable for being used in a national joint registry.While most of the identified national joint registries use the Kaplan-Meier method for analyzing implant survival, there was little agreement regarding the methods used for the early detection of implants that perform less efficiently than expected. Methods identified included revision rate per 100 component years, variants of statistical process control (SPC), cumulative sums (CUSUM) and funnel plots.Currently, there are no standardized methods for the early detection of inferior implants that are used by the established national joint registries. Most of the statistical methods that could be identified were either not used at all or only in a very limited number of registries. The value of these methods still needs to be established. It appears probable that the statistical methods for early detection have to be developed further in order to identify a possible inferior performance of implants at an earlier point in time. This is necessary in order to avoid that thousands of patients are again treated with implants which are associated with an increased revision rate.

Die langfristige Implantatüberlebensrate nach dem ersten Jahr nach Insertion ist eng mit dem Auftreten biologischer Komplikationen verbunden. Bislang existiert kein Goldstandard für die Therapie der Periimplantitis. Ziel dieser Studie war die Beurteilung von Langzeitergebnissen nach regenerativer Periimplantitistherapie. Das Kollektiv beinhaltete 22 Patienten (männlich= 10/ weiblich= 12; Durchschnittsalter= 61 Jahre) mit 36 Implantaten mit einer Periimplantitis. Die Implantate waren durchschnittlich 64 Monate bis zum Auftreten einer Periimplantitis in situ. Durchschnittlich 65 Monate vor der Langzeitnachuntersuchung war im Rahmen einer ersten Studie nach Abklingen der akuten Infektion durch chirurgische Therapie das Granulationsgewebe entfernt worden, die Implantate mit Ätzgel dekontaminiert und die Knochendefekte mit einer 1:1 Mischung aus autologem Knochen und xenogenem Knochenersatzmaterial mit Wachstumsfaktoren (Colloss) gefüllt worden. Im Rahmen dieser Langzeitnachuntersuchung erfolgte eine klinische Untersuchung mit Kontrollröntgenaufnahme und Vermessung des Knochens, Sondierung des periimplantären Gewebes mit Bestimmung des Blutungsindexes sowie des Pusverhaltens. In der Langzeitnachuntersuchung konnten 54% der ursprünglich behandelten Patienten nachuntersucht werden. Als Ergebnis stellten sich nach durchschnittlich 65 Monaten Nachuntersuchung 80% der kontrollierten Implantate in klinisch stabilem Zustand dar. Der periimplantäre Blutungsindex konnte um 47% verringert werden. In der Langzeitnachuntersuchung zeigte sich kein Pusaustritt bei periimplantärer Sondierung mehr. Die röntgenologische Auswertung der Knochendefekte zeigte bei den nachuntersuchten Implantaten eine durchschnittliche Reduktion um 51%, die Abnahme der Taschentiefe betrug durchschnittlich 47%. Diese Studie ist die einzige Langzeituntersuchung am Patienten und konnte mittels regenerativer Periimplantitistherapie weitgehend stabile Implantatverhältnisse in der Langzeitnachuntersuchung erzielen. Allerdings war bei einigen Patienten trotz aufwendiger Therapie auch eine Verschlechterung der Periimplantitis mit einer Implantatverlustrate von 20% zu verzeichnen. Dies unterstreicht die Bedeutung der Kenntnisse des Krankheitsverlaufs der Periimplantitis und der daraus resultierenden optimalen Behandlung. The long-term implant survival rate during the first years after insertion is connected closely with the occurrence of complications. Today no gold standard exists for the treatment of peri-implantitis. The aim of this study was to assess long-term results for regenerative peri-implantitis treatment. The analysis included 22 patients (male = 10 / female = 12; mean age = 61 years) with 36 implants with peri-implantitis. The implants were in average 64 months in situ until the occurrence of peri-implantitis. The long-term follow-up was performed after a mean time of 65 months. In the range of a first study granulation tissue of the acute infection had been removed by surgical therapy including decontamination of the implants with etching gel and filling of the bone defects with a 1:1 mixture of autogenous bone and xenogenic bone substitute material with growth factors (Colloss). As part of this long-term follow-up a clinical examination with x-ray diagnostics, measurement of the bone defects and probing of the peri-implant soft tissue including determination of the bleeding and pus characteristics was performed. In the long-term follow-up 54% of the originally treated patients were checked up. After a mean time of 65 months 80% of the controlled implants showed a clinical solid condition. The peri-implant bleeding index was reduced by 47%. In the long-term follow-up no pus occurred in peri-implant probing. In the radiographic evaluation the peri-implant bone defects showed an average reduction of 51%. The mean decrease in pocket depth was 47%. This study is the only long-term follow up on patients received regenerative peri-implantitis therapy. The long-term results after regenerative peri-implantitis therapy achieved largely stable implant conditions. However in some patients a worsening of the peri-implantitis with a loss rate of 20% of the implants was recorded. This underlines the importance of the knowledge of the process of peri-implantitis disease and the resulting optimal treatment.

The goal of the operation is limb-sparing resection of tumors arising from the proximal tibia with adequate surgical margins and local tumor control. Implantation of a constrained tumor prosthesis with an alloplastic reconstruction of the extensor mechanism to restore painless joint function and loading capacity of the extremity.Primary bone and soft tissue sarcomas. Benign or semimalignant aggressive lesions. Metastatic disease (radiation resistance and/or good prognosis).Poor physical status. Extensive metastatic disease with life expectancy6 months. Tumor penetration through the skin. Local infection or recalcitrant osteomyelitis. Poor therapeutic compliance. Large popliteal extraosseous tumor masses with infiltration of neurovascular structures.A single incision is made from the anteromedial aspect of the distal femur to the distal one third of the medial lower leg. Preparation of large medial and lateral fasciocutaneous flaps. The popliteal vessels are explored through a medial approach by releasing the pes anserinus and semimembranosus tendon, mobilizing the medial gastrocnemius muscle and detaching the soleus muscle from the tibial margo medialis. The anterior tibial artery and vein are ligated. If the knee joint is free of tumor, circumferential dissection of the knee capsule is performed and the patellar ligament is dissected. An osteotomy of the tibia shaft is performed with safety margins according to preoperative planning. In order to obtain adequate surgical margins, in some cases an en bloc resection of the tibiofibular joint becomes necessary. Therefore, the peroneal nerve is exposed. Parts of the M. tibialis anterior, a portion of the M. soleus and the entire M. popliteus are left on the resected tibial bone. After implantation of the prosthesis and coupling of the femoral and tibial component, the extensor mechanism is reconstructed using an alloplastic cord. It is passed transversely through the distal end of the quadriceps tendon looping the proximal margin of the patella. Both ends are passed distally through a subsynovial tunnel and are fixed under adequate pretension in a metal block of the tibial component. The detached hamstrings and remaining ligaments can be fixed on preformed eyes of the prosthesis. A medial gastrocnemius muscle flap is used to provide soft tissue coverage of the tibial component.Immobilization and elevation of the extremity for 5 days, then flap conditioning. Mobilization in a hinged knee brace locked in extension for 6 weeks without weight bearing. During this time active flexion with a stepwise progress, isometric quadriceps training. Then beginning of straight leg raising exercises, stepwise unlocking of the brace with 30° every 2 weeks. Weight-bearing is increased by 10 kg/week. Thrombosis prophylaxis until full weight-bearing. At follow-up, patients are monitored for local recurrence and metastases using history, physical examination and radiographic studies.Between 1988 and 2009, endoprosthetic replacement and alloplastic reconstruction of the extensor mechanism after resection of tibial bone tumors was performed in 17 consecutive patients (9 females and 8 males) with a mean age of 31.1 years (range 11-65 years). There were no local recurrences. Until now, 5 patients have died of tumor disease. One or more operative revisions were necessary in 53.9% of the patients. According to Kaplan-Meier survival analysis, the implant survival at 5 years was 53.6% and 35.7% at 10 years, respectively. In 2 cases, a distal transfemoral amputation had to be performed due to deep infection. There were 3 cases of tibial stem revision due to implant failure and aseptic loosening, respectively. In 3 patients, the hinge of the prosthesis had to be revised. Impaired wound healing occurred in 2 cases. Peroneal nerve palsy was observed in 3 patients with recovery in only one. The mean Oxford knee score for 9 of the 12 living patients was 30.7 ± 7.5 (24-36). No patient had a clinically relevant extension lag. The mean range of motion at the last follow-up was 90.2° ± 26.7 (range 35-130°). All patients were well satisfied with their postoperative outcomes.

Management of primary or secondary acetabular bone loss (D'Antonio type I-IV ). Implantation and stable fixation using a cementless, cranially extended oval press-fit cup to restore painless joint function and loading capacity.Septic or aseptic loosening of the acetabular component after total hip arthroplasty. Acetabular bone loss after tumor resection. Primary acetabular bone defects in developmental dysplasia of the hip.Persistent deep infection. Bone defects including the parts of the iliac bone adjoining the sacrum (fixation of the stem in the ilium is not possible any more).Complete exposure of the acetabular defect using a standard approach. Removal of the loose cup. Excision of soft and granulation tissue from the acetabular ground and the rim. Reaming of the acetabulum with sequentially larger hemispheric reamers until an adequate bony bed is created for the insertion of the cranial socket. Eccentric cranial sockets without a craniolateral flap are preferable for use in type I and II defects with teardrop lysis mostly involving the craniolateral acetabulum, if a trihedral press-fit fixation can be achieved. Supplementary screw fixation through the acetabular ground, is possible. If a type III defect is present, the authors recommend the use of cranial sockets with an anatomic flap in order to increase primary stability by supplementary screw fixation. This is especially recommended for the management of deficiencies in the medial or posterior wall. If there is pelvic discontinuity (type IV), adequate acetabular reconstruction with primary stability of the component can only be achieved by a supplementary intramedullary structured stem fixed in the dorsal part of the ilium.Partial loading of the operated limb with 10 kg for a period of 6-12 weeks. Then increased loading with 10 kg per week. Thrombosis prophylaxis until full weight bearing. Physiotherapy and gait training.A total of 50 cup revisions using the ESKA cranial socket system were clinically and radiologically analyzed with an average follow-up of 65.7+/-28.5 months (26-123 months). Defects were classified according to D'Antonio. There were 21 type II, 23 type III, and six type IV defects. The Harris Hip Score increased from 40 preoperatively to 68.3 points postoperatively. Four patients had recurrent hip dislocation requiring replacement of the inlay. In four cases of aseptic loosening, the acetabular component had to be revised. With revision of the acetabular component as an endpoint, implant survival was 92% after an average of 5.4 years.

An adequate primary stability and a subsequent stable osseous fixation (secondary stability) of artificial hip cups are required for long-term implant survival. The aim of this study was to analyse the design of cementless press-fit cups as an influencing factor of primary stability.Different hemispherical and conical cup designs were analysed. The fixation stability of the cups was detected experimentally using a spongiosa and a cortical model based on artificial bone as well as a numerical simulation using a spongiosa model by pull-out and lever-out tests. In addition, the stress on the osseous cup cavity was determined in the finite-element analysis.All tested cup designs revealed higher fixation stability in the cortical bone model compared to the spongiosa model. The experimental tests did not show an increase of fixation stability with the conical cup profile in comparison to hemispherical cup profiles.Therefore, cementless press-fit cups with conical cup profile do not provide a higher primary stability in comparison to hemispherical cups. Moreover, the stress on the bone cavity was lower inserting the hemispherical cup profiles in contrast to the conical profiles.

The point of time for total knee arthroplasty has a significant importance due to limited implant survival rate. To what extent the preoperative stage of physical and psychological function limitation, which is increasing with the progression of the osteoarthritis, has an influence on the early functional outcome after total knee arthroplasty should be clarified in a clinical evaluation.47 Patients were treated with the same bicondylar knee endoprosthesis system (Type Genia, ESKA Implants, Lübeck). A clinical evaluation was undertaken preoperatively and at 3 and 6 months postoperatively using HSS score, WOMAC index and SF-36 score. In relation to the preoperative HSS score the patients were allocated into three groups depending upon whether their level of function was "good", "average" or "poor". Additionally, all patients were assigned to three body mass index (BMI) groups (30, 30 - 35,35) which were descriptively analysed.The preoperative differences in HSS score and SF-36 score in all three groups show a high reduction after 3 and 6 months. Postoperatively there were no significant differences in all three groups at both timepoints. Patients with "poor" preoperative function achieved on average a lower score niveau than patients with preoperative "good" function, but have the benefit of the best function improvement. The early postoperative period (3 months) showed the highest decrease in physical and psychological function derogation. The BMI had no significant influence on the early functional outcome.Therefore, older people should receive early total knee arthroplasty to gain a high postoperative score niveau. In younger patients the indication for implant should be considered essentially because of the limited survival rate. Even in progressive osteoarthritis and extreme functional limitation the bicondylar surface replacement gives the possibility of a good early functional postoperative outcome. Total knee arthroplasty of obese patients is under attention of the perioperative internistic risks, a safe procedure with good functional results and can increase patient's mobility.

First public study reports of oral implant insertion were dated in the early 20th century. Besides the research for the best fitted material for the oral implants, great affords were done to achieve a periodontal like connection. In 1969 Brånemark et al report the outcome of their developed titanium implant. The success of this implant is attributed to a direct connection of bone with the implant (osseointegration). They recommend the submerged healing, three to four months in the lower and four to six months in the upper jaw before loading. Within this study ten edentulous patients were treated with each five machined-surface Brånemark implants in the lower jaw. After a healing period of up to 20 days, the implant supported prosthesis was fixed. After a follow up of five years, the overall long-term treatment outcome success was at 80%. The implants that did not osseointegrate have been removed and replaced ad modum Brånemark. The marginal bone levels were stable, after the first year of loading, the observed bone loss was within the suggested 0,2mm/year. Due to the high implant loss, the success criteria proposed by Albrektsson et al were not fulfilled by this study. The outcome of an oral rehabilitation with implants is influenced by several variables, which can be separated in three groups. The first group is determined by the patient and its given conditions like the different amount and quality of bone, which can barely be manipulated. The relationship between bone density, initial stability, and successful osseointegration has been generally accepted by clinicians and confirmed. Smoking and general diseases may have an influence for the outcome of the therapy, but at the moment cannot be properly determined, whereas habits like bruxism and clenching cause overwhelming stress on the early implant-bone contact. Poor oral hygiene is associated with increased marginal bone loss and thus might cause implant failures. Concerning the different materials, variables as the implant length, the surface, the direction of implant loading and the insertion torque are of great interest. At the beginning, there were many clinicians who recommended the use of long implants to achieve a strong bicortical anchorage with a high primary stability. Due to the results of present studies, the use of shorter implants is favoured. It could often be demonstrated, that there is a significant difference in removal torque values between machined implants an implants with rough surfaces, so that there is a high agreement in the recommended use of rough surface implants. The implants should be loaded axially to avoid destructive forces. There are also controversial opinions about the insertion torque. On the one hand, high torque values are strived for to achieve a high primary mechanical stability, on the other hand might these high torque values provoke necrosis and minifractures which endanger the implant healing. The operative and prostodontic procedure is similar to the unloaded healing except the healing time, which is of high importance for the manufacturing of the supraconstruction. New tryouts by using computertomographs allow the planning and manufacturing before inserting the implants and may avoid any complications. Although in this study machined implants were used with a reduced healing time of about 20 days and the early loading of the implants by a fixed prothesis in the lower jaw, there could be demonstrated an implant survival rate of 80%. On account of the high implant failures the success criteria proposed of Albrektsson et al were not fulfilled. The main reason for this high failure rates might probably the use of machined surface implants. At the time of implantation, there where no rough surface implants by Nobel Biocare available, which show better results in many following studies. Possible other reasons might be the loading within the first three weeks after insertion, reduced insertion torque values, the existence of occlusal contacts on the cantilevers, which might cause an overwhelming load on the distal implants. Additionally distal implants show higher peak axial forces and bending moments when antagonizing a removal denture. The sample size was small, but these results suggest that new studies need to be developed for al better understanding of the studied variables.

This prospective study describes This retrospective multicenter study was undertaken to calculate mid- and long-term survival rates of the cementless Zweymüller/Alloclassic total hip prosthesis.The rectangular titanium stem and threaded cup have been in use since 1986. The ball head is made of alumina ceramic, the inlay of UHMW polyethylene. Five hospitals in Austria, France and Germany cooperated in the follow-up of 848 patients operated between October 1986 and September 1990 (mean age 62.2 years, 62% women, 38% men, mean patient weight 73.8 kg, body mass index 26.8). 468 patients were followed clinically, 320 patients interviewed on the phone, 29 sent a letter. No information was available concerning the remaining 31 patients. Probabilities of implant survival were estimated with the Kaplan-Meier method.98 patients (11.5%) had died at a median follow-up time of 81.1 months. The probability of survival at 81.1 months was 98.6% looking at stem and cup. There was no significant association of survival of the prosthesis and patient weight, gender or body mass index.Our results are in accordance with previously published data of smaller series using the Zweymüller/Alloclassic( total hip. The survival rate of this cementless rectangular titanium prosthesis for the reported follow-up time compares favorably with contemporary cemented hip prostheses.

After resection of the ACL, the knee exhibits a paradoxical movement but the effect of this movement on function,wear, and implant survival in a meniscal bearing total knee replacement (TKR) is not known. Up to now, only radiological methods are described to measure the meniscal bearing's movement. We developed a method using ultrasound for analyzing MB motion. In an in vitro study we compared ultrasound of 5 MHz with 8 and 12 MHz, we studied the effect of malrotation on the projection of plain and digital radiographs, and compared ultrasound of 8 MHz with plain and digital radiographs. In all three methods the distance was measured between the anterior border of the tibial component and the anterior rim of the meniscal bearing. The accuracy and precision of 8 and 12 MHz were identical and statistically significantly more accurate than 5 MHz (p0.01). Malrotation had a significant impact on the radiological projection. Neutral rotated radiographs and ultrasound of 8 MHz did not differ in accuracy and precision, but ultrasound was significantly more accurate than any radiograph with a malrotation of 1 degrees or more (p0.001). We conclude that ultrasound of 8 MHz is an alternative to radiological methods for the measurement of meniscal bearings' motion.

Ziel der vorliegenden Studie war es Ergebnisse über den Langzeiterfolg der verwendeten BONE-LOCK®Implantate bei der Rehabilitation teilbezahnter und zahnloser Patienten vorzulegen. In der Zeit von Juli 1988 bis Oktober 1997 wurden bei 222 Nicht-Tumor-Patienten insgesamt 718 BONE-LOCK®-Implantate an der Universitätsklinik für Mund-, Kiefer- und Gesichtschirurgie der Universität Würzburg inseriert. Die Beurteilung der periimplantären Gewebe zeigte eine sehr zufrieden stellende Weichgewebssituation, in Kombination mit einem meist sehr guten Mundhygienezustand der Patienten. Die Taschensondierungstiefen weisen einen Mittelwert von 3,55 mm auf. Die Beurteilung der Implantate mittels Hygieneindex und Periotestmessung fiel sehr gut aus. Die Auswertung der erhobenen Daten anhand des Kaplan-Meier-Verfahrens ergab für das Implantat-System eine indikationsunabhängige Erfolgsquote von 78,13 % über einen Gesamtzeitraum von 9 Jahren. Die Erfolgsquoten der vorliegenden Studie an Nicht-Tumor-Patienten im Vergleich zu einer Untersuchung an Tumorpatienten fiel mit einer 8-Jahreserfolgsquote von 62,8 % schlechter aus, als die Erfolgsrate nach 8 Jahren beim Tumorpatientengut mit 71,4 %. Es ergab sich für die Erfolgsquote der zahnlosen Patienten der niedrigste Wert mit 76,65 % und für die Indikation „Schaltlücke“ die beste Überlebensrate von 87,18 % im gesamten Untersuchungszeitraum. Im Vergleich der beiden Entwicklungsstufen des BONE-LOCK®-Systems fiel auf, dass das BONE-LOCK®-II-System mit einer 4-Jahreserfolgsquote von 82,9 % gegenüber dem BONE-LOCK®-I-System mit einer Erfolgsrate von 68,5 % nach 4 Jahren deutlich bessere Ergebnisse vorlegen kann. Zusammenfassend lässt sich feststellen, dass das System im Vergleich mit anderen Implantatsystemen etwas schlechtere Erfolgsraten aufweist, wobei in vorliegender Untersuchung das in Bezug auf den Erfolg eines Implantates sehr kritische erste Jahr der Einheilphase vor prothetischer Versorgung mitberücksichtigt wurde., The aim of the presented study was to review the long-term outcome of the Bone-Lock-implant-system for rehabilitation of partially and totally edentulous patients. During a 9-year period (1988-1997) 718 Bone-Lock-implants were installed in 222 patients at the Maxillo-Facial-Surgery-Department of the university of Würzburg. The indication for implantation hereby was not cancer in the maxillofacial-region. The patients with cancer were investigated in a separate study. Standardized annual clinical examinations were conducted as much as possible and for the statistical analysis the Kaplan-Meier method was applied to describe implant survival based on implant losses. The clinical examination of the tissues around the implants showed very satisfying results with good oral hygiene and compliance of the patients. The mean probing depth of 3,55 mm and the mean periotest results with 1,12 represent the very healthy implant conditions. The Kaplan-Meier analysis of the collected data showed a survival rate of 78,13 % for all implants over the 9 years without differentiation of the indication for implantation. In comparison to the same study of Bone-Lock-implants with cancer-patients these results are surprisingly worse. The cancer-patient-implants present 71,4 % survival rate in the 8-year examination period, whereas this present study showed 62,8 % survivals after 8 years. The implants with the indication of the edentulous jaw had the worst survival rates with 76,65 % and those provided with removable bridges showed the best results with 87,18 % over the whole examination period. Comparing both systems the survival rate of the Bone-Lock II after 4 years showed a markedly better percentage with 82,9 %, while the Bone-Lock-II-System had a rate of 68,5 % after the 4 year period. The results of this study are slightly worse than those of other systems, but it has to be pointed out, that the very important first year after the implantation, the critical healing period, has also been included for the statistical analysis. Other studies often leave out this critical year of their examination and can herewith show better survival rates.

Due to a configuration defect, the use of membrane-guided bone regeneration or alveolar ridge extension is required. The bone splitting and bone spreading technique was modified by developing the osteotome technique and the osteotome kit (Summers 1994). Lateral and apical bone displacement and condensation are the principles of this nonablative implant bed preparation technique. Estimation of the periimplant bone level is one of the important prognostic parameters for estimating implant survival. The level of the alveolar crest near implants which were inserted using the osteotome technique was investigated by measuring the differences between the alveolar crest and the implant shoulder in postoperative radiographs after implant insertion and after uncovering the implants in 17 patients. The osteotome technique was used in bone quality D2 and D3 according to the classification by Misch (1993). Significant differences were found between the bone levels after implant insertion and implant uncovering. A significant correlation (r = 0.5466; P = 0.023) was calculated between the differences of the marginal bone level at implantation and uncovering time and the bone quality. There should be strict indications for using the osteotome technique for evaluating the bone quality found at the implant site to optimize the long-term prognosis of the implants.

Endosteal implants after tumor surgery of the face are helpful in reconstructing facial defects. A retrospective study of our patients treated using craniofacial implants was conducted to evaluate long-term results. A total of 128 implants were inserted, 110 implants in the periorbital, 12 implants in the mastoid, and six implants in the paranasal region; 113 implants were short craniofacial Brånemark implants, and 15 implants were dental implants. The success rate for implant survival was 94.5%. Long-term results were promising and more than satisfactory, leading to a large indication for these endosteal implants.

Twenty-three patients with class VI atrophy of the maxilla were treated with horseshoe Le Fort I osteotomy. In ten patients, simultaneous placement of the implants was carried out, and in 12 the implantation was done in a second procedure 6-9 months later. A total of 178 implants were placed, and 15 were lost. In one patient, five implants were lost due to an oronasal fistula, leading to loss of part of the bone graft. The implant survival rate for all the implants was 89.0-88.2% in the one-step procedure and 90.0% in the two-step procedure. There was no difference between the one-step and the two-step procedure with respect to the peri-implant soft tissues in follow-up of least 2 years after implantation. We favor the two-step procedure because it allows more precise positioning of implants.

A total of 409 implants was inserted into 83 consecutive patients, who had tumor-related intraoral resections of soft tissue and bone. A life table analysis was used to determine the survival rate of the implants placed over a period of 13 years. Log rank tests and a Cox regression analysis were employed to identify relevant effects of surgical parameters on implant survival. A total of 38 implant failures were encountered. Most of the losses (n = 16) occurred during the first year of functional loading. The cumulative, overall survival rate of implants was 56.5%. Previous radiation therapy, insertion into grafted bone or original jaw bone, and insertion into microsurgically revascularized grafts did not significantly affect the survival rates. In the Cox regression, only the timing of implant placement was significantly related to the survival rate in the group of patients with bone grafts (P = 0.0197), with a lower survival rate of 36.2% of primary inserted implants and 67.1% survival in the group with secondary implant placement.

Das Ziel dieser Arbeit war es zu evaluieren, inwieweit Kurzschaftkonzepte eine Alternative zu herkömmlichen Standardschäften hinsichtlich Implantatstabilität, funktionell- radiologischem Ergebnis sowie periprothetischem Knochenumbau darstellen. Kurzschäfte zeigen Migrationsmuster, die als frühe postoperative Mikrobewegung mit anschließender kontinuierlicher Stabilität beschrieben werden können. Kurzschäfte können den Standardschäften vergleichbare klinische Ergebnisse liefern. Schenkelhalserhaltende Konstruktionen weisen hinsichtlich des Implantatüberlebens schlechtere Ergebnisse auf., The aim of this work was to evaluate if short stem concepts represent an alternative to conventional standard stems with regard to implant stability, functional- radiological results and periprosthetic bone remodeling. Short stems show migration patterns that can be described as early postoperative micro-movement followed by continuous stability. Short stems can provide clinical results comparable to standard stems. Femoral neck-preserving constructions show poorer results in terms of implant survival.