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The main requirement for performing the one-stage septic exchange is the pre-operative identification of the pathogen and its susceptibility. The purpose of this study is to evaluate the success rate with special focus on reinfection in a cohort of patients who underwent one-stage septic knee or hip revision for pre-operative culture-negative PJI.We retrospectively analyzed 640 patients treated by one-stage revision for chronic knee or hip PJI between January 1, 2016, and December 31, 2018. Only cases with pre-operative culture-negative PJI, with culture-negative synovial aspirations and one negative open biopsy, were analyzed. We evaluated the septic and aseptic complication and the rate of complication-free survival defined as the time from the date of first operation and the date of complication events.A total of 22 patients fulfilled the inclusion and were enrolled. The mean age of the group was 73.2 ± 9.8 years, with a median ASA score of 3 (range 3-4). After mean follow-up of 3.6 ± 2.6 years, 86.4% (19 out of 22) of patients reported no complications. Two patients (9.1%) after one-stage hip required revision arthroplasty due to septic failure, while one patient (4.5%) with one-stage knee had revision for femoral component aseptic loosening.Our analysis suggests that the absence of pre-operative pathogen detection may not be contraindication to the one-stage revision in selected patients. The one-stage exchange might be considered in patients with pre-operative negative cultures in presence of ASA 3 and multiple comorbidities that are not able to tolerate multiple surgeries.

The use of short-stemmed femoral components with preservation of the femoral neck has been advocated for younger and more active patients undergoing joint replacement. This study reports the long-term outcomes of the Collum Femoris-Preserving (CFP) prosthesis on a previous report.Between January 1999 and December 2000, a total of 149 patients underwent total hip arthroplasty procedure using the CFP stem in a single institution. At latest follow-up, 79 patients were available and were included in this study. The mean age of the cohort was 73.4 (range, 44-92 years) with a mean follow-up of 20.7 years (range 20-21). The average age was 52.1 years at index procedure (range, 21-71 years).The Kaplan-Meier survivorship free from revision for any cause at 5, 10 and 20 years was 93.2% (87.8-96.3%), 93.2% (87.8-96.3%) and 83.0% (75.7-88.3%), respectively. At 20 years follow-up, the revision for any cause occurred in 26.6% (21 of 79) of patients. The most common causes for revision surgery were aseptic loosening, dislocation, and polyethylene wear with 6.3% (5 out of 79), respectively. Periprosthetic fracture occurred in four patients (5.1%) followed by periprosthetic joint infection in two patients (2.5%). Revision surgery of the femoral stem was required in four patients (5.1%). There was a statistically significant improvement of the Harris Hip Scores from 53 to 83.7 (range 56-91).The long-term outcomes of the CFP stem are excellent, demonstrating a low rate of aseptic loosening with an excellent survivorship within 2 decades.

Recurrent hip dislocation after multiple revision total hip arthroplasty is a severe complication. Therefore, constrained acetabular liners (CL) have been used during salvage procedures. We report our experience of constrained liners in a re-revision setting with focus on re-dislocation. We also evaluated acetabular and femoral bone loss as potential risk factor.Between January 2013 and December 2016, 65 patients were treated in a single institution for revision and re-revision hip arthroplasty using CL. The indication for using a CL was a high risk of re-redislocation after multiple recurrent hip dislocation including failed Dual Mobility Cups (DMC). Compromising soft tissue defects as well as severe bone defect were therefore regarded as high risks. Thirty-eight patients (77.6%) underwent a minimum of three surgical procedures before the index revision procedure. Sixteen patients (24.6%) were excluded as they were lost to follow-up, expired before minimum follow-up or refused study participation, leaving 49 patients in the analysis (75.4%). The mean follow-up was 62 months (44-74; SD = 7.7). We assessed the following potential risk factors for revision or dislocation: type of surgical setting (septic/aseptic), BMI, cup inclination angle, size of liner used and acetabular and femoral bone loss according to Paprosky classification. The primary endpoints were dislocation or repeat revision for any reason.Of the 49 patients, we found an overall re-revision rate of 40.8% (20/49) and a dislocation rate of 30.6% (15/49). There were no significant differences among the surgical re-revision rate or dislocation rate as a factor of patient characteristics. In terms of bone loss, there was a trend towards higher revision rates for increasing acetabular and femoral bone loss, but without statistical significance.We found the use of a constrained liner in a re-revision setting still bears a high risk of re-revision and re-dislocation. Therefore we restrained from using constrained liners in favour of Dual mobility cups. In this study there was no significant higher dislocation rate in the subgroup of periprosthetic infection. Furthermore the rigid design of a constrained liner bears the known risk of structural failure of acetabular reconstruction implants. Severe acetabular or femoral bone defects seem to have an impact on the revision rate, but not on the dislocation rate with regards to the restored offset and center of the hip. Results have to be taken into context such that the study population inherently has a predisposition for poorer outcomes. Indications should be strongly filtered for patients at high risk for recurrent hip joint dislocation including failed DMCs with only limited bone loss and moderate soft tissue defects. Our modification to the existing classification with a high inter and intraobserver reliability will make future studies more comparable regarding revisions and bone stock loss. Still further research using objective and reproducible parameters is needed to better analyze data especially in the background of complex revision hip arthroplasty.

The rates of unicompartmental knee arthroplasty (UKA) are increasing yet little data exists regarding management of periprosthetic joint infections (PJI) after UKA, particularly utilizing one-stage revision. The aim of this study was to determine the septic and all-cause revision-free survival of UKA PJIs treated with one-stage revision, as well as functional outcomes and risk factors for failure.A retrospective review of one-stage septic revisions with a hinged or rotating hinged implant between 2000 and 2015 at a single institution was performed. Results of 15 patients with a minimum of 3-year follow-up (mean = 93 months; range 37-217) were evaluated by means of infection control, survivorship, patient reported functional score and possible causal factors for a re-revision. Kaplan-Meier curves and Cox regression analysis were used.After a mean of 8 years of follow-up infection control rate was 93.3%, the survivorship free of any reoperation, including both septic and aseptic causes, was 80% at 5 years and 64.2% at ten years and average Lysholm score was 72.7 ± 21.3 (33-100).One-stage revision for PJI of UKA using a hinged knee design has excellent infection-free survival at mid to long-term follow-up. Likewise, patient reported functional outcomes are promising. However, one-third of patients required aseptic reoperation and aseptic loosening was the dominant etiology.

Re-operation after septic failure of a one-stage exchange for prosthetic joint infection (PJI) of the knee is a highly challenging procedure with concerns over residual bone stock, soft tissues, and stability. The associated changes in microbiology in cases of reinfection are still largely unknown.A comprehensive analysis was performed of all patients treated at our tertiary institution between 2001 and 2017 who developed reinfection after a one-stage exchange for PJI of the knee. Prerequisites for inclusion were a certain diagnosis of PJI according to the ICM criteria and a minimum follow-up of three years. Data on comorbidities, previous surgical interventions, microbiological findings at the time of the initial one-stage exchange and at the time of reinfection, detection methods, and antibiotic resistance patterns were retrospectively studied.Sixty-six patients were identified that met the inclusion criteria. Reinfection occurred after a mean time interval of 27.7 months (SD ± 33.9, range 1-165). Ten types of bacteria were found that were not present before the one-stage exchange. The causative pathogen remained identical in 22 patients (33%) and additional microorganisms were detected in ten patients (15%). Half of the reinfections were however due to (a) completely different microorganism(s). A significant increase in the number of PJIs on the basis of high-virulent (23 vs 30, p = 0.017) and difficult-to-treat bacteria (13 vs 24, p = 0.035) was found.The present study provides a novel insight into the microbiological changes following septic failure after one-stage exchange for PJI of the knee. A higher prevalence of more difficult-to-treat bacteria might increase the complexity of subsequent procedures. Also, a longer follow-up of these patients than previously suggested seems in order.

Aseptic loosening (AL) is the second most common reason for failure after one-stage septic knee revision. In this context, the goal of the study is to identify risk factors for AL following one-stage septic knee revision using rotating hinge implants. We aimed to answer the following research question: How does the anatomical shape of the distal femur represent an independent risk factor for AL following one-stage septic knee revision arthroplasty?Patients, who had undergone re-revision surgery due to AL of the rotating hinge knee prosthesis after one-stage septic knee revision arthroplasty between January 2008 and December 2018, were included. For this purpose, 41 patients with AL after one-stage septic knee revision using rotating hinge implants and 37 controls without any revision surgery at latest follow-up were included in this study. Using standardized anteroposterior (AP) views of the knee in all patients, we measured the inner diameter of the femur 20 cm proximally from the joint line and at a point 2 cm proximally from the adductor tubercle.Among the vast majority of AL cases, we identified an isolated loosening of the femoral component. The AL group showd a high distribution of the Type C according to the Citak classification with 75.7%. Contrary to this, with 24.3% (p 0.001) the amount of Type C cases was relatively low in the control group. Consequently, Type C configurations of the distal femur represent an independent risk factor for AL with an approximately sevenfold higher risk for AL compareed to Type A and Type B.The novel radiological classification system of the distal femur shows that the Type C subtype is an independent and main risk factor for AL after one-stage septic knee revision using rotating hinge knee implants.

Despite good clinical outcomes and a high success rate, there is a comparatively high mortality after one stage septic exchange of total hip arthroplasty. The aim of this study was to identify risk factors for mortality in the hospitalization period after one-stage septic exchange of THA. We retrospectively analyzed in our database all patients who had a one-stage septic exchange for periprosthetic infection of THA and died during hospitalization (n = 33). The control group was matched semi-randomly by surgical procedure (n = 121) who did not die during hospitalization. The two groups were analyzed for risk factors such as age, Charlson Comorbidity Index (CCI), and high-/low-virulence bacteria. In the deceased group, 16 patients were female and 17 were male with a mean age at surgery of 73.2 years. In the control group, there were 55 females and 66 males with an average age at surgery of 68.2 years. Comparing the two groups, the deceased group had a significantly higher proportion of liver disease as well as higher rate of pulmonary embolism, apoplexy, and/or myocardial infarction, an increased CCI with an average of 6.5 and advanced age. Further demographic and surgery-related parameters especially high- or low-virulent germs were not identified as risk factors for mortality during the hospitalization period. The binominal logistic regression analysis showed that the probability of an inpatient death following one-stage septic exchange of THA increases by a factor of 3.079, with each additional point of the CCI. In conclusion, advanced age and high CCI are the main risk factors for mortality after single-stage septic change of THA. However, high-virulence bacteria have no influence on the mortality during the hospitalization period after one-stage septic exchange of THA.

This study aimed to determine the risk factors of aseptic loosening (AL) in complex revision total knee arthroplasty (TKA) cases using rotating hinge knee prosthesis. Patients who had undergone re-revision rotating hinge prosthesis surgery between January 2012 and December 2017 were included. Parameters related to AL were retrospectively reviewed. For this purpose, 31 aseptic loosening patients and 30 control patients were included in the study. Various risk factors were evaluated. Risk factors for AL after re-revision were determined using univariate and multiple logistic regression analyses. Thirty-one AL patients and 30 control patients were included. In the AL group, tibial tantalum cone and impaction grafting were performed significantly less frequently than the control group (p = 0.002 and p < 0.001). Logistic regression analysis revealed that smoking, right-sided TKA, and large femoral canal anteroposterior diameter were factors that increased the risk of AL after re-revision, while tibial tantalum cone decreased the risk of loosening. Smokers had an 11.847-fold higher risk for AL; right-sided TKA led to a 4.594-fold higher risk for AL. However, the presence of a tibial tantalum cone was associated with an 8.403-fold lower risk for AL. We conclude that smoking, right-sided prosthesis, and large femoral canal diameter increased the risk of AL, while tantalum cone and impaction grafting reduced this risk in patients who underwent re-revision surgery with rotating hinge prosthesis after TKA.

Das Thymuskarzinom des Erwachsenen ist eine seltene Diagnose. Wir prasentieren den Fall eines 47-jahrigen Mannes, der bei bekannter Spondylolisthese L5/S1 in langer konservativ-orthopadischer Behandlung war. Bei im Verlauf auftretender Schmerzexazerbation der unteren Lendenwirbelsaule zeigte sich schnittbilddiagnostisch eine Raumforderung (RF) des Lendenwirbelkorpers drei. Eine Biopsie dieser RF ergab den Befund eines multipel metastasierten Thymuskarzinoms vom Plattenepithelzelltyp. Nach palliativem Therapieansatz verstarb der Mann 9 Monate nach Diagnosestellung.

Die Endoprothetik ist zu einer auserst erfolgreichen Operationsmethode mit hervorragenden Langzeitergebnissen geworden. Die gezielte Diagnostik zum Ausschluss einer Osteoporose vor einem Gelenkersatz und der Einsatz von Medikamenten zur Verbesserung des Ergebnisses bei Gelenkersatz konnen derzeit nicht empfohlen werden. Im Bereich der Knieendoprothetik sollte bei bekannter Osteoporose immer zementiert werden. Gleiches ist fur die Hufte zu empfehlen, auch wenn fur die acetabulare Komponente zementfrei gute Ergebnisse erzielt werden. Die zugige Belastung und Mobilisierung erscheinen vorteilhaft, auch mit Blick auf die Osteoporose und ihre systemische Behandlung.

Introduction The Kellgren-Lawrence score helps the orthopedic surgeon to classify the severity of knee osteoarthritis (OA) before total knee arthroplasty (TKA). There might be a discrepancy between subjective complaints of the patients and radiologically visible changes of the knee joint in many cases. In this context, we performed a prospective clinical study to compare the preoperative degree of knee OA using the Kellgren-Lawrence score with the intraoperative extent of cartilage damage during primary TKA. Materials and methods A total of 251 primary TKA surgeries due to a primary knee OA were prospectively included. Preoperative Kellgren-Lawrence score was determined using standardized preoperative plain radiographs of three views; anteroposterior, lateral and skyline of the patella by a senior radiologist. Intraoperatively, in all cases, photographs of the medial, lateral, and patellofemoral joint compartments were taken. Using the International Cartilage Repair Society (ICRS) score, the degree of chondromalacia was assessed. Subsequently, correlation analysis was performed using the Pearson-Clopper 95% confidence interval (CI). Results There were higher intraoperative scores compared to the preoperative scores in 160 of all cases (63.7% of 251, 95% CI 57.5-69.7%). A mismatch of two score grade points was found in 8.4% (95% CI 5.3-12.5%). The most common mismatch was noted in patients with preoperative Kellgren-Lawrence score of 3 and an intraoperative score of 4 in 48.2% (95% CI 41.9-54.6%). Conclusions The preoperative radiographs using Kellgren-Lawrence underestimate the severity of knee osteoarthritis. The true extent of articular cartilage damage can be better appreciated intraoperatively. In patients undergoing primary TKA, the correlation of clinical symptoms with radiological findings is crucial in deciding when to perform the surgery. Besides, other imaging modalities may be used as an adjunct when the clinical findings and plain radiographs do not correlate.

Degradation at the modular head-neck interface in total hip arthroplasty (THA) is predominately expressed in the form of corrosion and fretting, potentially causing peri-prosthetic failure by adverse reactions to metal debris. This retrieval study aimed to quantify variations in stem taper surface topographies and to assess the influence on the formation of corrosion and/or fretting in titanium alloy stem tapers combined with metal and ceramic heads. Four hip stem designs (Alloclassic, CLS, Bicontact and SL-Plus) were characterized using high-resolution 3D microscopy, and corrosion and fretting were rated using the Goldberg scoring scheme. Quantification of the taper surface topographies revealed a high variability in surface characteristics between threaded stem tapers: Alloclassic and CLS tapers feature deeply threaded trapezoid-shaped profiles with thread heights over 65 µm. The sawtooth-shaped Bicontact and triangular SL-Plus taper are characterized by low thread heights below 14 µm. Significantly lower corrosion and fretting scores were observed in lightly threaded compared to deeply threaded tapers in ceramic head combinations. No significant differences in corrosion or fretting scores with thread height were found in pairings with metal heads. Understanding the relationship between stem taper surface topography and the formation of corrosion and fretting could help to improve the performance of modern THAs and lead to longer-lasting clinical results.

Mechanical failure due to dislocation, fracture and acetabular wear is a major complication associated with the use of spacers in the management of periprosthetic joint infection (PJI). We have developed a novel custom-made spacer in the setting of two-stage septic revision hip arthroplasty and present the preliminary results of our technique. Between May 2015 and November 2017, 30 patients underwent hip revision using the ENDO spacer technique in the setting of a two-stage septic exchange arthroplasty. The technique involves the dual mobility liner and the downsized stainless cemented straight stem in combination with antibiotic-loaded PMMA bone cement. The primary outcome measure was the overall spacer complication rate, particularly spacer dislocation. Furthermore, functional outcome using the Harris Hip Score (HHS) before spacer implantation and prior re-implantation was evaluated. The mean age of the patients was 69.8 years (range from 45 to 85; SD = 9.9 years). No microorganisms were preoperatively found in 23 (76.7%) cases. Successful re-implantation was performed in all patients after a mean spacer duration time of 53.6 days (range 14–288 days; SD = 48.2). Spacer-related complications occurred in only two patients (6.7%). The HHS significantly improved from 34.0 (range 3–62; SD = 15.1) to 48.1 (range 11–73; SD = 15.7) (p = 0.0008). The ENDO spacer surgical technique is a feasible option in the treatment of periprosthetic joint infection (PJI), with a low dislocation rate. Furthermore, it allows early mobilization with the possibility of full-weight bearing.

In recent years, the minimally invasive joint-preserving implant system has been developed. The main goal of this device is to unload the medial knee compartment without affecting the lateral compartment. The current authors describe a severe metallosis and elevated chromium in serum following implantation of the joint unloading implant system of a 50-year-old male patient, presented to our hospital 3 years after implantation of a KineSpring System into his left knee due to unicompartmental medial osteoarthritis (OA) in an external hospital. Radiographs showed radiological signs for loosening of the screws in the tibia and a progressive OA on the medial and patellofemoral compartments. Revision surgery with removing of the unloading device was performed at our hospital. The intraoperative situs presented a severe metallosis around the device. Five days after revision surgery, the laboratory parameters revealed an elevated value for chromium in serum, while nickel and cobalt values in serum were normal. Reliable clinical data about the long-term results of the KineSpring System is desperately needed. Further studies are warranted to work out the effects of cobalt and chromium levels and further side effects following the implantation of the extra-articular absorber system.

The aim of this study was to determine the survival rate, the causes of failure, and the functional outcomes of an all-polyethylene tibial unicompartmental knee prosthesis. One hundred (100) nonselected, consecutive patients indicated for unicompartmental knee replacement for isolated medial knee compartment osteoarthritis by a single surgeon at a single institution from 2000 to 2004 were included in this study. Data was collected retrospectively at final follow-up from the hospital electronic database, including progress notes, demographic information, Hospital for Special Surgery (HSS) Knee Score, details on the surgical procedure, reoperations/revisions, and mortality. A survival analysis was performed to estimate the probability of survival over time. The survival probability of the all-polyethylene UKA implant was 95.4 % after a mean follow-up of 8 years, which is comparable to reports from studies using metal-backed modular designs for UKA. The causes of failure were progression of arthritis in adjacent compartments (2 %) and loosening of the tibial component (2 %). The mean preoperative HSS knee score improved from 36.6 ± 14.3 to 76.6 ± 21.6 at latest follow-up (p

This retrospective study was performed to determine the effectiveness of preventing recurrent dislocation following primary cemented Endo-MarkIII/SP2 total hip replacement using a posterior lip augmentation device (PLAD). Between January 2003 and Dezember 2006, 27 PLADs were used in the treatment of recurrent hip dislocation in 27 patients who had received a cemented primary total hip arthroplasty using Endo-MarkIII/SP2 (Waldemar LINK, Hamburg, Germany) components. The mean number of dislocations prior to stabilization with this specific device was 2.6 (range 2–4, SD ± 0.4) with a mean time to revision surgery of 10 months (IQR 13). The mean age of the patients at time of revision surgery was 81.5 years (range 70–94, SD ± 6.9). The control group evaluating the clinical outcome using the Harris Hip Score (HHS) also received a cemented primary total hip arthroplasty using the same implants. A retrospective clinical and radiological review was carried out at a mean follow-up of 68.5 months (range 30–103, SD ± 17.7). Of the 27 patients, 6 had died at the time of the latest review, with the posterior lip augmentation device still in situ and without reported further dislocation after PLAD application. In 2 of the remaining 21 patients recurrent dislocation occurred, thus a subsequent revision of respective implants had to be performed to achieve persistent joint stability. At latest follow-up no deep infection or implant loosening occurred. Surgical treatment of recurrent dislocation following primary cemented Endo-MarkIII/SP2 total hip replacement using a posterior lip augmentation device is a safe and effective procedure which can lead to a secondary stabilization of the total hip arthroplasty in about 90 % of the patients.

Stem loosening in both cemented and uncemented total hip arthroplasty is the hallmark of the Vancouver type B2 classification of periprosthetic hip fractures. We discuss the technique we use at our institution for treating these fractures. Periprosthetic femoral-shaft fractures are associated with a relatively high mortality rate, approximating that of patients with hip fractures. Outcomes are directly associated with early mobilisation and construct stability. We recommend performing the procedure only when the surgeon is proficient in revision hip surgery and trauma care. A well-selected portfolio of different stem designs and an array of osteosynthesis devices should be available, as well.

Dwarfism is a challenge in arthroplasty. The anatomical features provide a lot of pitfalls. The aim of this study was to follow-up growth-restricted patients after endoprosthetic treatment. 138 knee arthroplasties in patients with a height ≤150 cm between January 1, 2000 and May 5, 2013 at our institution were enrolled in this study. 124 cases were available for 1-year follow-up. Out of these, 43 cases were available for 5-year follow-up so far. 14 patients were lost to follow-up. IKS score increased from 35 ± 16 on admission to 67 ± 22 (p

Hintergrund Der histopathologischen Infektionsdiagnostik des periimplantaren Gelenkinfekts kommt insbesondere in der Revisionsendoprothetik ein wesentlicher diagnostischer Stellenwert zu. Dies ist durch nationale und internationale publizierte Expertenempfehlungen und durch publizierte Konsensusklassifikationen belegt.

In the setting of end-stage osteoarthritis of the knee, total knee arthroplasty is the gold-standard treatment. Recently, a minimally invasive, joint preserving treatment option in the treatment of medial osteoarthritis of the knee has been developed. It is called the KineSpring(®) (Moximed(®) International GmbH, Zurich, Switzerland). The goal of this novel device is to reduce medial compartment loading without significantly affecting the loading of the lateral compartment. In this context, the current authors present a case of device failure using these new implants, which at 7 months post-op necessitated revision surgery with complete removal of the device.

Bei gelenkimplantatallergischen/toxischen Fragestellungen als Ursache fur ein Endoprothesenversagen ist die Neosynovialis/periprothetische Membran („synovial-like interface membrane“, SLIM) gemas der erweiterten SLIM-Konsensus-Klassifikation zu klassifizieren: Typ I, Partikelerkrankung, so genannte „aseptische Lockerung“; Typ II, bakterielle Infektion, so genannte „septische Lockerung“; Typ III, Kombination von bakterieller Infektion und Partikelerkrankung; Typ IV, mechanische Ursachen und funktionelle Storungen; Typ V, ossare Pathologien; Typ VI, endoprothesenassoziierte Arthrofibrose; Typ VII, allergische/immunologische/toxische Reaktionen auf Implantatmaterialien. Die histopathologische Identifikation der Prothesenmaterialpartikel erfolgt gemas des Partikelalgorithmus nach Krenn. Histopathologisch sind die Veranderungen bei Verdacht auf Allergie/Toxizitat des Implantatmaterials zwar charakteristisch, lassen aktuell aber keine eindeutige Unterscheidung zwischen primar toxischen und primar immunologischen Reaktionen zu. Die charakteristischen Veranderungen umfassen den Partikelnachweis, eine ausgepragte lymphozytare, plasmazellulare und makrophagozytare Infiltration, Nekrosen und Granulome bzw. granulomartige Strukturen. In der Maximalauspragung wird dieser Befund als sog. inflammatorischer Pseudotumor bezeichnet. Da Lymphozyteninfiltrate in der SLIM vom Typ I und Typ IV nicht notwendigerweise Ausdruck einer implantatmaterialallergischen Reaktion oder einer Toxizitatsreaktion sind und bislang keine beweisenden zellularen Marker einer pathogenen implantatallergischen Reaktion fur das Gelenkendoprothesenversagen definiert sind und der genaue immunologischen Zusammenhang ungeklart ist, kann die Diagnose einer allergischen Typreaktion/toxischen Reaktion auf Implantatmaterialien in einer SLIM nur im Kontext von histopathologischen, dermatologischen, allergologischen und klinisch-orthopadischen Befunden gestellt werden. Gewebeproben sollten aus verschieden Regionen (SLIM, prothesennah und -fern und eine getrennte Entnahme von Knochengewebe) entnommen werden, um eine suffiziente histopathologische Diagnose zu ermoglichen.

The characteristics of tantalum augment osseointegration in human ex vivo specimens from re-revision procedures are unknown and limited data in this regard is available. The purpose of this study was to investigate the osseointegration pattern into porous tantalum augmentations harvested during re-revision procedures.Between 2007 and 2010 a total of 324 hip and knee revisions with a tantalum augmentation were performed in our institution. Out of this cohort, seven patients (2.2 %) had to be re-revised. To analyse the status of trabecular ingrowth in the retrieved cases (four hips, three knees), all specimens were analysed by contact radiography, subjected to undecalcified processing, histology, thin-section analysis and backscattered electron imaging.Trabecular and vascular ingrowth could be found along the bone-augment-interface in two of seven revised specimens, respectively. The depth of bone ingrowth reached up to 2.6 mm. However, the analysis of the remaining cases revealed no bony ingrowth into trabecular metal. Rather, large parts of the implants were embedded in cement or pores were filled with autologous bone.Although the cause for the missing bony ingrowth seems to be multifactorial, some fundamental conditions, such as the provision of the greatest possible interface between the tantalum implant and the host bone, should be met and thus, bone cement and autologous bone grafts should be used with caution.

Short stem prostheses that preserve the femoral neck are becoming more and more popular. The CFP (collum femoris preserving) has been introduced especially for the treatment of younger patients. However, information about remodelling, complications and learning curve are thus far rare. We present a retrospective study of 155 patients (average age 59.3 ± 9.9 years) who underwent total hip replacement with the CFP prosthesis. Follow-up was obtained 74.3 ± 9.4 months postoperatively. The Harris hip score revealed excellent and good results in 96%. One stem had to be exchanged due to aseptic loosening revealing a survival rate of 99% and 100% for stem and cup, respectively. Radiological analysis showed typical patterns of remodelling with apearance of cortical thickening predominantly in the distal part of the prosthesis. Implant related revision rate was

Die Standzeit von Endoprothesen groser Gelenke hat in den letzten Jahrzehnten zugenommen. In einer nordamerikanischen Studie wurde fur Huftendoprothesen eine 10-Jahres-Standzeit von 94% ermittelt, europaische Daten weisen Standzeiten von 88–95% aus. Aus Sicht des Pathologen ergeben sich atiologisch folgende wesentliche Erkrankungsgruppen fur die „Pathologie der Endoprothese“, welche zu einer Reduktion der Prothesenstandzeit fuhren: die periprothetische Partikelerkrankung (sog. aseptische Lockerung), die Infektion (septische Lockerung) und die periprothetische Ossifikation und die Arthrofibrose. Vier Typen der Neosynovialitis bzw. der periprothetischen Membran sind in einer Konsensusklassifikation zusammengefasst: abriebinduzierter Typ [Typ I, mittlere Prothesenstandzeit (mPS) 12 Jahre], infektioser Typ (Typ II, mPS=2,5 Jahre), Mischtyp (Typ III, mPS=4,2 Jahre) und Indifferenztyp (Typ IV, mPS=5,5 Jahre). Die Arthrofibrose wird histopathologisch in 3 Grade eingeteilt: Grad 1 benotigt zur Diagnosestellung immer klinische Informationen, wohingegen Grad 2 und 3 eindeutige histopathologische Befunde ausweisen.

Histopathological examination of synovial specimens can contribute to the diagnosis of chronic joint diseases. A so-called synovitis score has been introduced as a standardised grading system, based on the semi-quantitative evaluation of the three determining features of chronic synovitis: enlargement of synovial lining, density of synovial stroma and inflammatory infiltrate, giving a score between 0 and 9. The present study examines the reliability of this procedure by comparison with exact measurements using computer-assisted image analysis (CAIA). Seventy-one synovial specimens from patients with osteoarthritis (OA, n=22), psoriatic arthritis (PsA, n=7), rheumatoid arthritis (RA, n=35) and from a control group (Co, n=7) were evaluated using both the synovitis score and CAIA. The measurements were transformed to semi-quantitative values analogous to the synovitis score. The differences between the transformed CAIA scores and the pathologist's scores were 0 or +/-1 in 40 cases, whereas in 31 cases the difference was greater than 1 (correlation coefficient r=0.725). The CAIA scores differed significantly between Co and RA cases (p=0.000) as well as between OA and RA (p=0.000). We conclude that the synovitis score was validated by CAIA and can be regarded a reliable grading system that contributes to the diagnostic procedure of chronic joint inflammation.

Mittels cDNA-Microarrays konnten konstant differenziell exprimierte entzundungsassoziierte Gene in der abriebinduzierten und infektiosen periprothetischen Membran nachgewiesen werden. Ziel der vorliegenden Arbeit ist die Validierung der Microarraydaten, um signifikante Unterschiede im Genexpressionsprofil auf RNA- und Proteinebene darzustellen. Gewebeproben von 16 abriebinduzierten und 20 infektiosen periprothetischen Membranen wurden mittels RT-PCR und Immunhistologie auf die Expression entzundungsassoziierter Gene untersucht. Mittels RT-PCR konnten die Gene cd9, cd11b, cd18 und cd52 sowie pdgfrβ in Interfacemembranen nachgewiesen werden. Die Immunhistochemie zeigte in der abriebinduzierten Membran eine signifikant geringere Genexpression von PDGFRβ, dagegen eine differenzielle Uberexpression von CD9, CD11b und CD52. CD18 zeigte keinen signifikanten Expressionsunterschied zwischen abriebinduziertem und infektiosem periprothetischem Gewebe. Unterschiedliche Typen der periprothetischen Membran spiegeln sich in differenten Genexpressionsprofilen wider. Mittels RT-PCR und Immunhistochemie konnten die Microarraydaten der Gene cd9, cd11b, cd52 und pdgfrβ validiert werden. Die Bestimmung der Genprodukte von cd9, cd11b und cd52 im Blut oder im Gewebe kann helfen, eine abriebinduzierte von einer infektiosen Lockerung zu unterscheiden.

About 10% of hip endoprostheses will loosen after 10 years. Prosthesis loosening is caused by two different pathomechanisms: aseptic loosening (AL) and septic loosening (SL). This study evaluated differences in gene expression in AL and SL. Eight hybridizations were performed on PIQOR cDNA arrays. Objects of the study were periprosthetic interface tissue samples from two patients with SL and three patients with AL. Tissue parts directly adjacent to the site of RNA isolation were analyzed immuno/histopathologically in order to overcome the problem of tissue heterogeneity. Thirty-three genes were found constantly differentially expressed, among which were cd11b, cd18, cd68, osteopontin and ferritin heavy-chain upregulated in AL and collagen types 1alpha-1, 3alpha-1, integrin alpha-1, thrombospondin2 and nidogen upregulated in SL. The most striking finding was the strong upregulation (from 20-fold to 323-fold) of megakaryocyte stimulating factor (msf) in all aseptic cases and one of the two septic cases, which was confirmed by real-time reverse transcription-polymerase chain reaction. In this study, msf is linked to prosthesis loosening for the first time. The upregulation in AL suggests an important pathogenetic role: the msf splice product lubricin is responsible for the lubrication of healthy joints, but its excellent lubrication ability may disturb the tight interaction between bone and prosthesis and thereby contribute to prosthesis loosening.

Schonender Zugang zum Huftgelenk mit geringem Verletzungsrisiko von Gefasen und Nerven, geringem Blutverlust und guter Ubersicht uber koxales Femurende, Huftpfanne und hinteren Beckenpfeiler. Implantation von Endoprothesen, Prothesenwechsel und Azetabulumfrakturen mit Abbruch des hinteren Pfeilers. Keine. Von einer bogenformigen Hautinzision vom Gesas uber den Schenkelhals und Trochanter major nach distal wird der Musculus glutaeus maximus vom Musculus glutaeus medius sowie der Glutaalfaszie abprapariert und die subtrochantare Femurregion freigelegt. Durchtrennung aller Ausenrotatoren nah an ihrem Ansatz am koxalen Femurende. Palpation des Nervus ischiadicus am innenrotierten Bein. Ablosung des Gelenkkapsel am dorsalen Pfannenrand, Eroffnung des Gelenkes und Luxation des Huftkopfes. Resektion des Schenkelhalses und Huftkopfes. Implantation der Endoprothese. Abschliesend transossare Reinsertion der Gelenkkapsel und der Ausenrotatoren, Reinsertion des Musculus glutaeus maximus. Von 1212 Patienten wurden 948 (78,2%) kontrolliert, und zwar 559 (46,1%) nachuntersucht, 225 (18,6%) durch, Fragebogen und Rontgenaufnahmen erfast und 164 (13,5%) anlaslich Wechseloperationen uberpruft. 170 Operierte (14%) waren verstorben, 94 (7,8%) nicht zur Kontrolle erschienen. In den ersten sechs Monaten nach der Operation war es bei 13 Patienten (1,1%) zu Luxationen gekommen. Nach dieser Zeit konnten noch weitere funf (0,4%) Luxationen beobachtet werden. Von den im ersten Haljahr luxierten Huftgelenken konnten zehn geschlossen reponiert werden. Bei einem Patienten war ein Schaftwechsel, bei zweien ein Prothesenwechsel erforderlich. Von den spater, luxierten Gelenken gelang eine geschlossene Reposition bei drei Patienten. Ein Pfannenwechsel war notwendig sowie eine weitere Operation mit Implantation eines Antiluxationsringes. Die Resultate anderer Autoren im Vergleich zwischen dorsalem und lateralem Zugang sind in Tabelle 1, die Gesamtkomplikationen im eigenen Krankengut in Tabelle 3 dargestellt.

We have read the recent article by Dr. Romano et al. [6] with great interest. The number of periprosthetic infections associated with hip and knee arthroplasties is increasing worldwide. In addition to the clinical problems they present, the financial burden of each case is high and the socioeconomic costs are increasing each year. The current standard treatment options for eradicating such infections are oneand twostage exchanges. The literature overview seems to be biased. The wellperformed review by Jamsen et al. [4] failed to show a difference between the oneand two-stage approaches. Romano et al. conclude that better eradication rates may be achieved by a two-stage approach. We were wondering why the retrospective analysis by Mortazavi et al. [5] was not mentioned although it was online in the summer of 2011 and presented the previous year in a meeting. Mortazavi et al. concluded that there are currently no proper indicators that can guide orthopaedic surgeons in patient selection between a two-stage exchange and a reimplantation. Next, they observed that the failure rate after two-stage reimplantation for infected TKA is relatively high. There were no variables identified that would guide the surgeon to perform the second stage. It is therefore very surprising that 1 year later, another group is able to make a clear statement using a meta-analysis. Next, we would like to mention a recent published article by Singer et al. [7]. They stated that the rate of infection control for one-stage revision of infected knee arthroplasties is still unclear according to the literature. For their series, they observed an infection control rate of 95 % for one-stage protheses and higher knee scores were reported than for two-stage revisions. This contrasts greatly with Dr. Romano et al.’s study. The worst series in the article by Romano et al. comes from our own institution by von Foerster et al. [8]. These patients were treated around 1980. Algorithms regarding topical antibiotic choice have improved in the last three decades, and although they are still missing in the literature, we currently observe better outcomes. This study is the only outlier in their overview and seems to present misleading results and conclusions. The combination of germ-specific systemic and topical antibiotic therapy is the key to success. Recent publications identified much higher infection control rates for the one-stage approach to septic THA exchanges [1, 2]. Such actual data are missing for septic TKA exchanges. As one of the biggest centres for revision arthoplasties in the world, we prefer a one-stage approach in septic TKA surgery because it is well documented that one-stage surgery is associated with less stress for the patient, fewer complications, better surgical conditions and better functional results [3]. There is currently a strong trend favouring one-stage approaches. However, we have to state that valid literature data are still missing and that this review misleads the reader. This comment refers to the article available at doi:10.1007/s00167-012-1885-x.