Intramedullary nailing versus plate compound osteosynthesis in subtrochanteric and diaphyseal pathologic femoral fractures: a retrospective cohort study.

PURPOSE: Pathologic fractures of the extremities due to carcinoma metastases require individual and patient prognosis-related stabilization procedures. Quick remobilization of the patient to restore the quality of life is of high importance, especially in the case of subtrochanteric and diaphyseal femoral fractures. In our retrospective cohort study, we evaluated intraoperative blood loss, length of operation, complication rate, and regain of lower extremity function in plate compound osteosynthesis (PCO) versus intramedullary nailing (IM) for subtrochanteric and diaphyseal pathologic fractures of the femur. METHODS: Between January 2010 and July 2021, we retrospectively reviewed 49 patients who were treated at our institution for pathologic fractures of the subtrochanteric and diaphyseal femurs for group differences in terms of blood loss, length of operation, implant survival, and Musculoskeletal Tumor Society (MSTS) score. RESULTS: We included 49 stabilization procedures of the lower extremity due to pathologic fractures of the proximal or diaphyseal femur, with a mean follow-up of 17.7 months. IM (n = 29) had a significantly shorter operation time than PCO (n = 20) (112.4 ± 9.4 and 163.3 ± 15.96 min, respectively). We did not detect any significant differences in terms of blood loss, complication rate, implant survival, or MSTS score. CONCLUSION: Based on our data, pathologic subtrochanteric and diaphyseal fractures of the femur can be stabilized with IM, which has a shorter operation time than PCO, but the complication rate, implant survival, and blood loss remain unaffected.

Temporary arthrodesis through static spacer implantation in two-stage treatment of periprosthetic joint infections of the knee.

OBJECTIVE: Treatment of chronic periprosthetic joint infection of the knee requires the removal of the implant and thorough debridement, with reimplantation in a second stage surgery. Intramedullary spacers can be helpful during the interval between explantation and reimplantation and provide a temporary arthrodesis which fixes the knee in extension preserving leg length and administers local antibiotic therapy. INDICATIONS: Periprosthetic joint infection of the knee with large bony defects and severe infection of the native joint with advanced destruction/infiltration of the cartilage and bone and/or ligament insufficiency. CONTRAINDICATIONS: Suspected antibiotic resistance of the microbiological pathogen to local antibiotic drugs, incompliant patient, and known allergy to bone cement or antibiotic. SURGICAL TECHNIQUE: After implant removal, suitable metal rods are coated with antibiotic-loaded bone cement and inserted into the cleaned intramedullary canals of femur and tibia. Rods are joined at the joint line with a connector and joint space is filled with more bone cement to achieve temporary and very stable arthrodesis. POSTOPERATIVE MANAGEMENT: Partial weight-bearing and no flexion/extension while spacer is in place; second stage reimplantation as soon as infection is controlled. RESULTS: Complications related to the spacer were rare (5.3%). Reimplantation of an implant was possible in 95 of 113 patients (84%), of those, 23 (20%) received an arthrodesis. Of the 95 patients that were reimplanted, 14 showed signs of recurrent infection. Mean time to last follow-up was 15.6 months post reimplantation. Mean knee pain was 2.9/10; overall function was good; 6 patients had an extension lag; mean total range of motion was 88°.

Effects of an Integrated Geriatric-Orthopedic Co-management (InGerO) on the Treatment of Older Orthopedic Patients with Native and Periprosthetic Joint Infections.

PURPOSE: In view of our aging society, co-management with a geriatrician is becoming increasingly important. While such collaborations have been working successfully in trauma surgery for years, it is still unclear whether they are also helpful for non-trauma patients in orthopedics. The aim of this study was to investigate the effect of such a cooperation in orthopedic non-trauma patients with native and periprosthetic joint infections on the basis of five key areas. RESULTS: Analysis was carried out with 59 patients "with" and 63 "without" geriatric co-management. In the co-management group, delirium was detected significantly more often (p < 0.001), significantly lower pain intensities were measured at the time of discharge (p < 0.001), transfer ability had clearly improved more (p = 0.04), and renal function was more frequently noted (p = 0.04). No significant differences were found with respect to principal diagnoses, surgical procedures performed, complication rates, pressure ulcer and delirium incidence, operative revisions, or length of inpatient stay. CONCLUSION: Orthogeriatric co-management in orthopedic patients with native and periprosthetic joint infections and nontraumatic surgery appears to have positive impacts on recognition and treatment of delirium, pain management, transfer performance, and attention to renal function. Further studies should follow in order to conclusively assess the value of such co-management in orthopedic nontraumatic surgery patients.

Femoral defects in revision hip arthroplasty: a therapy-oriented classification.

INTRODUCTION: The complex field of femoral defects in revision hip arthroplasty displays a lack of standardized, intuitive pre- and intraoperative assessment. To address this issue, the femoral defect classification (FDC) is introduced to offer a reliable, reproducible and an intuitive classification system with a clear therapeutic guideline. MATERIALS AND METHODS: The FDC is based on the integrity of the main femoral segments which determine function and structural support. It focuses on the femoral neck, the metaphysis consisting of the greater and lesser trochanter, and the femoral diaphysis. The four main categories determine the location of the defect while subcategories a, b and c are being used to classify the extent of damage in each location. In total, 218 preoperative radiographs were retrospectively graded according to FDC and compared to intraoperatively encountered bone defects. To account for inter-rater and intra-rater agreement, 5 different observers evaluated 80 randomized cases at different points in time. RESULTS: A Cohens kappa of 0.832 ± 0.028 could be evaluated, accounting for excellent agreement between preoperative radiographs and intraoperative findings. To account for inter-rater reliability, 80 patients have been evaluated by 5 different observers. Testing for inter-rater reliability, a Fleiss Kappa of 0.688 could be evaluated falling into the good agreement range. When testing for intra-rater reliability, Cohens Kappa of each of the 5 raters has been analyzed and the mean was evaluated at 0.856 accounting for excellent agreement. CONCLUSION: The FDC is a reliable and reproducible classification system. It combines intuitive use and structured design and allows for consistent preoperative planning and intraoperative guidance. A therapeutic algorithm has been created according to current literature and expert opinion. Due to the combination of the FDC with the recently introduced Acetabular Defect Classification (ADC) a structured approach to the entire field of hip revision arthroplasty is now available.

APP-guided assessment of acetabular defects in hip revision arthroplasty: a structured approach to a complex situation.

INTRODUCTION: Acetabular defect recognition and classification remains a challenging field of practice for orthopedic surgeons. Recently, the Acetabular Defect Classification (ADC) has been introduced to provide a reliable, reproducible and intuitive classification system. In order to improve ease of use and efficiency of the ADC, a browser-based application has been created. We hypothesized that the ADC application can improve rating performance of non-specialists (medical students) to achieve good inter- and intra-rater agreement and will compare favorable to the results of specialists (experienced surgeons) without the help of the application. MATERIALS AND METHODS: The ADC is based on the integrity of the acetabular rim and the supporting structures. It consists of four main types of defects ascending in severity. These defects are further subdivided in A-C, narrowing down defect location. 80 randomized radiographs were graded according to ADC by three non-specialists (medical students) with help of the ADC application and by three specialists (orthopedic surgeons) without help of the application to evaluate the difference in inter-rater agreement between groups. To account for intra-rater agreement, the rating process was repeated after a reasonable wash-out period. RESULTS: Inter-rater and intra-rater agreement within the non-specialist group rated lower when compared to the specialist group while still falling into the good agreement range. The student group presented with k values of 0.61 for inter-rater agreement and 0.68 for intra-rater agreement, while the surgeon group displayed k values of 0.72 for inter-rater agreement and 0.83 for intra-rater agreement. CONCLUSION: The app-guided assessment of acetabular defects offers a promising innovative approach to simplify complex situations. It makes the challenging field of acetabular revision arthroplasty more approachable especially for less experienced surgeons and offers insight and guidance in the planning stage as well as intra-operative setting.

The Impact of Drug Interactions in Patients with Community-Acquired Pneumonia on Hospital Length of Stay.

(1) Background: An aging society is frequently affected by multimorbidity and polypharmacy, which, in turn, leads to an increased risk for drug interaction. The aim of this study was to evaluate the influence of drug interactions on the length of stay (LOS) in hospitals. (2) Methods: This retrospective, single-centre study is based on patients treated for community-acquired pneumonia in the hospital. Negative binomial regression was used to analyse the association between drug interactions and the LOS in the hospital. (3) Results: The total cohort contained 503 patients, yet 46 inpatients (9%) that died were not included in the analyses. The mean age was 74 (±15.3) years, 35% of patients older than 65 years were found to have more than two drug interactions, and 55% had a moderate, severe, or contraindicated adverse drug reaction. The regression model revealed a significant association between the number of drug interactions (rate ratio (RR) 1.02; 95%-CI 1.01-1.04) and the severity of drug interactions (RR 1.22; 95%-CI 1.09-1.37) on the LOS for the overall cohort as well as for the subgroup of patients aged 80 years and older. (4) Conclusion: Drug interactions are an independent risk factor for prolonged hospitalisation. Standardised assessment tools to avoid drug interactions should be implemented in clinical routines.

sCD28, sCD80, sCTLA-4, and sBTLA Are Promising Markers in Diagnostic and Therapeutic Approaches for Aseptic Loosening and Periprosthetic Joint Infection.

Aseptic prosthetic loosening and periprosthetic joint infections (PJI) are among the most frequent complications after total knee/hip joint arthroplasty (TJA). Current research efforts focus on understanding the involvement of the immune system in these frequent complications. Different immune cell types have already been implicated in aseptic prosthetic loosening and PJI. The aim of this study was to systematically analyze aspirates from knee and hip joints, evaluating the qualitative and quantitative composition of soluble immunoregulatory markers, with a focus on co-inhibitory and co-stimulatory markers. It has been shown that these molecules play important roles in immune regulation in cancer and chronic infectious diseases, but they have not been investigated in the context of joint replacement. For this purpose, aspirates from control joints (i.e., native joints without implanted prostheses), joints with TJA (no signs of infection or aseptic loosening), joints with aseptic implant failure (AIF; i.e., aseptic loosening), and joints with PJI were collected. Fourteen soluble immunoregulatory markers were assessed using bead-based multiplex assays. In this study, it could be shown that the concentrations of the analyzed immunoregulatory molecules vary between control, TJA, AIF, and PJI joints. Comparing TJA patients to CO patients, sCD80 was significantly elevated. The marker sBTLA was significantly elevated in AIF joints compared to TJA joints. In addition, a significant difference for eight markers could be shown when comparing the AIF and CO groups (sCD27, sCTLA-4, sCD137, sCD80, sCD28, sTIM-3, sPD-1, sBTLA). A significant difference was also reached for nine soluble markers when the PJI and CO groups were compared (sLAG-3, sCTLA-4, sCD27, sCD80, sCD28, sTIM-3, sPD-1, IDO, sBTLA). In summary, the analyzed immunoregulatory markers could be useful for diagnostic purposes as well as to develop new therapeutic approaches for AIF and PJI.

The Performance of a Dithiothreitol-Based Diagnostic System in Diagnosing Periprosthetic Joint Infection Compared to Sonication Fluid Cultures and Tissue Biopsies.

PURPOSE: The aim of this study was to evaluate the performance of a commercially available dithiothreitol (DTT) kit for routine use in diagnosing periprosthetic joint infections (PJIs) in comparison to conventional microbiological tissue specimens and sonication procedures in a maximal care hospital. METHODS: We applied the DTT system in 40 consecutive cases of revision arthroplasty (23 PJIs and 17 aseptic revisions), with an exchange or a removal of components. The hardware components were split between the DTT system and the conventional sonication procedure. At least three tissue biopsies and a joint fluid specimen were sent for microbiological and histopathological analysis. Data was analysed retrospectively to compare between the different methods. RESULTS: Cultures of the DTT fluid showed a sensitivity of 65% and specificity of 100%, as referenced to conventional microbiological cultures. Sonication had better sensitivity (75%) but lower specificity (85%). The categorical agreement of DTT cultures compared to sonication fluid cultures was 78% (31/40). Neither pathogen type, infection duration nor antibiotic pretreatment influenced the accuracy of the DTT, but a low pH in the DTT seemed to be associated with false-negative results. CONCLUSION: DTT was inferior in sensitivity when diagnosing PJIs compared to sonication fluid cultures and tissue biopsies. A low pH in the DTT fluid correlated with false-negative results. Nevertheless, the closed system of the DTT kit avoids contamination and false-positive results, and DTT can be an alternative where sonication is not available.

Evaluation of the Feasibility of a Telemedical Examination of the Hip and Pelvis - Early Lessons from the COVID-19 Pandemic. / Evaluation der Durchführbarkeit einer telemedizinischen Untersuchung des Hüftgelenks und des Beckens ­ frühe Lehren aus der COVID-19-Pandemie.

INTRODUCTION: Due to the current COVID-19 pandemic, the German Health Ministry has issued restrictions applying to the field of orthopaedics and trauma surgery. Besides postponement of elective surgeries, outpatient consultations have been drastically reduced. Parallel to these developments, an increase in telemedical consultations has reflected efforts to provide sufficient patient care. This study aims to evaluate the feasibility of a clinical examination of the hip joint and pelvis by way of a telemedical consultation. MATERIALS AND METHODS: Twenty-nine patients of a German university clinic were recruited and assessed in both telemedical and conventional examinations. Agreement between the two examinations was then assessed, and connections between the observed agreement and patient-specific factors such as age, BMI and ASA classification were investigated. RESULTS: The inspections agreed closely with a mean Cohen's kappa of 0.76 ± 0.37. Palpation showed adequate agreement with a mean Cohen's kappa of 0.38 ± 0.19. Function showed good agreement with a mean Cohen's kappa of 0.61 ± 0.26 and range of motion showed adequate agreement with a mean Cohen's kappa of 0.36 ± 0.19. A significant positive correlation was observed between the number of deviations in the different examinations and age (p = 0.05), and a significant positive correlation was shown between the number of non-feasible examinations and age (p < 0.01), BMI (p < 0.01) and ASA classification score (p < 0.01). DISCUSSION: Inspection and function can be reliably evaluated, whereas the significance of palpation, provocation and measurement of range of motion is limited. The small sample size puts limitations on the significance of a statistically relevant correlation between patient-specific factors such as age, BMI and ASA classification score and valid and successful implementation of a telemedical examination. The authors recommend targeted patient selection. If, however, patients are being evaluated who are very old (> 75 years), obese (BMI > 30) or with multiple comorbidities (ASA 3 and above), caution is advised. Large, prospective studies are needed in the future to fully validate telemedical consultations in the fields of orthopaedics and trauma surgery. CONCLUSION: A telemedical examination of the hip joint and pelvis can be performed with certain limitations. Patient-specific factors such as age, BMI, and extent of comorbidities appear to have a relevant impact on validity and execution of the examination. Patients with multiple comorbidities (ASA 3 and above), advanced age (> 75 years) or obesity (BMI > 30) should, whenever possible, be examined in a conventional outpatient setting.

Difficult-to-treat pathogens significantly reduce infection resolution in periprosthetic joint infections.

Periprosthetic joint infection (PJI) is a feared complication after arthroplasty. Our hypothesis was that PJI caused by difficult-to-treat (DTT) pathogens has a worse outcome compared with non-DTT PJI. Routine clinical data on 77 consecutive patients with confirmed PJI treated with 2-stage exchange arthroplasty were placed in DTT and non-DTT PJI groups and analyzed. The main outcome variable was that the patient was definitively free of infection after 2 years. We found definitive infection resolution in 31 patients in the DTT group (68.9%) and 28 patients (87.5%) in the non-DTT group (P < 0.05). The necessity for revision surgery until assumed resolution of infection was significantly more frequent in the DTT group with 4.72 ± 3.03 operations versus 2.41 ± 3.02 operations in the non-DTT group (P < 0.05). PJI caused by DTT bacteria is associated with significantly higher numbers of revision operations and significantly inferior definitive infection resolution.

Preoperative Anaemia in Primary Hip and Knee Arthroplasty. / Präoperative Anämie in der Hüft- und Kniegelenkendoprothetik.

INTRODUCTION: Approximately one in three patients has untreated preoperative anaemia, which in turn is associated with an increased need for transfusion of allogenic red blood cell concentrates (RBC) and complications in the context of a surgical intervention. Here, the prevalence of preoperative and postoperative anaemia as well as their effects on transfusion rate, hospital length of stay and hospital mortality in primary hip and knee arthroplasty has been analysed. METHODS: From January 2012 to September 2018, 378,069 adult inpatients from 13 German hospitals were analysed on the basis of an anonymized registry. Of these, n = 10,017 patients had a hip and knee joint primary arthroplasty. The primary endpoint was the incidence of preoperative anaemia, which was analysed by the first available preoperative haemoglobin value according to the WHO definition. Secondary endpoints included in-hospital length of stay, number of patients with red blood cell concentrate transfusion, incidence of hospital-acquired anaemia, number of deceased patients, and postoperative complications. RESULTS: The preoperative anaemia rate was 14.8% for elective knee joint arthroplasty, 22.9% for elective hip joint arthroplasty and 45.0% for duo-prosthesis implantation. Preoperative anaemia led to a significantly higher transfusion rate (knee: 8.3 vs. 1.8%; hip: 34.5 vs. 8.1%; duo-prosthesis: 42.3 vs. 17.4%), an increased red blood cell concentrate consumption (knee: 256 ± 107 vs. 29 ± 5 RBC/1000 patients; hip: 929 ± 60 vs. 190 ± 16 RBC/1000 patients; duo-prosthesis: 1411 ± 98 vs. 453 ± 42 RBC/1000 patients). Pre-operative anaemia was associated with prolonged hospital stay (12.0 [10.0; 17.0] d vs. 11.0 [9.0; 13.0] d; p < 0.001) and increased mortality (5.5% [4.6 - 6.5%] vs. 0.9% [0.7 - 1.2%]; Fisher p < 0.001) compared to non-anaemic patients. In patients aged 80 years and older, the incidence of preoperative anaemia and thus the transfusion rate was almost twice as high as in patients under 80 years of age. SUMMARY: Preoperative anaemia is common in knee and hip primary arthroplasty and was associated with a relevant increase in red blood cell concentrate consumption. In the context of patient blood management, a relevant potential arises, especially in elective orthopaedic surgery, to better prepare elective patients, to avoid unnecessary transfusions and thus to conserve the valuable resource blood.

Force plates may be used for dynamic analyses of endoprostheses explantation procedures.

The number of hip and knee arthroplasty replacement surgeries is increasing steadily. In combination with demographic aging and the number of periprosthetic complications, this development has lead to the phenomenon where the need for revision surgery is rising. The problem is, that, while implantation procedures of hip arthroplasties are more or less standardized, explantation is a non-standardized task for experienced specialists, due to the unpredictability of the adequate loosening method. The surgeon often only gets to decide on which tools and methods may be applied to detach the prosthesis, only after getting access to the operation site. The time taken to detach the prosthesis is hardly predictable and mainly depends on the surgeons' skills. To gain objective data on the mechanics of explantation, new measurement methods are required. One technical base for studies on revision procedures are standard force plates, available in biomechanics laboratories.

[Obesity in Revision Total Knee Arthroplasty - a Systematic Review and Legal Assessment]. / Adipositas in der Revisionsendoprothetik des Kniegelenks ­ eine systematische Literaturübersicht und rechtliche Bewertung.

BACKGROUND: In recent years, the incidence of overweight and obesity has increased in the German population. Thus the number of obese patients treated with primary total joint arthroplasty has also increased. It is therefore predicted that the number of obese patients undergoing revision total joint arthroplasty will also increase. Nevertheless almost every manufacturer of commercially available revision arthroplasty implants states in his product safety guarantee that obesity is a relative or absolute contraindication. Data on revision total joint arthroplasty in obese patients are sparse. The aim of this systematic review is to assess the current literature on re-revision rate, infection rate, postoperative clinical outcome, and implant survival rate in obese patients undergoing revision total knee arthroplasty. Moreover, potential legal consequences and aspects are discussed which are essential for the surgeon. MATERIAL AND METHODS: We conducted a systematic review of the online databases PubMed and identified clinical studies on obesity and overweight in revision total knee arthroplasty. Study quality was assessed using levels of evidence and the modified Jadad score. We also included descriptive data on case numbers, age, gender, height, weight and follow-up time. Current legal aspects were also analysed. RESULTS/DISCUSSION: Five studies met the inclusion criteria and were included in the systematic review. The average Jadad score was 1, the average level of evidence 3. In two studies, infection and revision occured more often in obese patients. Patients with morbid obesity had a higher risk of wound revision and periprosthetic joint infections. Three studies showed that obese patients had significantly lower scores for clinical outcome measures in function and pain. The legal aspect was not discussed in any of the five studies. Overall, published data are sparse and very heterogeneous. Therefore comparing these five studies is difficult. However, the results of our review suggest that obesity in revision total knee arthroplasty may have a negative influence on reoperation rate, infection rate and postoperative functional outcome. From a legal point of view, potential weight limitations of the implants intented for use have to be part of the oral preoperative discussion. The patient's informed consent has to be received and documented prior to revision total joint arthroplasty.

Indication Criteria for Total Knee Arthroplasty in Patients with Osteoarthritis - A Multi-perspective Consensus Study.

Background and Objectives Knee osteoarthritis (OA) is a significant public health burden. Rates of total knee arthroplasty (TKA) in OA vary substantially between geographical regions, most likely due to the lack of standardised indication criteria. We set out to define indication criteria for the German healthcare system for TKA in patients with knee OA, on the basis of best evidence and transparent multi-stakeholder consensus. Methods We undertook a complex mixed methods study, including an iterative process of systematic appraisal of existing evidence, Delphi consensus methods and stakeholder conferences. We established a consensus panel representing key German national societies of healthcare providers (orthopaedic surgeons, rheumatologists, pain physicians, psychologists, physiotherapists), payers, and patient representatives. A priori defined consensus criteria were at least 70% agreement and less than 20% disagreement among the consensus panel. Agreement was sought for (1) core indication criteria defined as criteria that must be met to consider TKA in a normal patient with knee OA, (2) additional (not obligatory) indication criteria, (3) absolute contraindication criteria that generally prohibit TKA, and (4) risk factors that do not prohibit TKA, but usually do not lead to a recommendation for TKA. Results The following 5 core indication criteria were agreed within the panel: 1. intermittent (several times per week) or constant knee pain for at least 3 - 6 months; 2. radiological confirmation of structural knee damage (osteoarthritis, osteonecrosis); 3. inadequate response to conservative treatment, including pharmacological and non-pharmacological treatment for at least 3 - 6 months; 4. adverse impact of knee disease on patient's quality of life for at least 3 - 6 months; 5. patient-reported suffering/impairment due to knee disease. Additional indication criteria, contraindication criteria, and risk factors for adverse outcome were also agreed by a large majority within the multi-perspective stakeholder panel. Conclusion The defined indication criteria constitute a prerequisite for appropriate provision of TKA in patients with knee OA in Germany. In eligible patients, shared-decision making should eventually determine if TKA is performed or not. The next important steps are the implementation of the defined indication criteria, and the prospective investigation of predictors of success or failure of TKA in the context of routine care provision in Germany.

Factors influencing the success of anterior cruciate ligament repair with dynamic intraligamentary stabilisation.

PURPOSE: Primary repair of the anterior cruciate ligament (ACL) has regained interest of clinicians with recent development of novel repair techniques. Dynamic intraligamentary stabilisation was introduced in an attempt to promote healing by shielding cyclic loads acting upon the ACL during the healing phase. The aim of this study was to identify negative factors likely to influence success of this procedure. METHODS: Between 2009 and 2014, 264 patients with an acute ACL rupture undergoing dynamic intraligamentary stabilisation were included in this study. Patients were evaluated for anterior/posterior laxity; range of motion and patient reported outcome measures. Adverse events and re-operations were noted. Failure was defined as AP Translation >3 mm, re-rupture or conversion to ACL reconstruction. Minimum follow-up was 24 months. Univariate and multivariate regression models were utilized to determine predictors of failure. RESULTS: An overall complication rate of 15.1% was noted comprising 9.5% (n = 25) re-ruptures, 4.1% (n = 11) persistent instability, and 1.5% (n = 4) > 10° fixed flexion deformity. Two factors were identified as negative predictors of failure: (1) pursuit of competitive sport activities with a Tegner pre-injury score >7 (Odds Ratio (OR) 4.4, CI 1.2-15.9, p = 0.02) and (2) mid-substance ACL rupture location (OR 2.5, 1.1-5.7, p = 0.02). When neither of those risk factors occurred the failure rate was limited to 3.9%. CONCLUSIONS: Correct patient selection and narrowing of indications are necessary to maintain high success rates of the procedure. Mid-substance ACL ruptures and a high pre-injury sports activity level are two predictors of inferior outcome. LEVEL OF EVIDENCE: II.

Can 3D ultrasound identify trochlea dysplasia in newborns? Evaluation and applicability of a technique.

Femoro-patellar dysplasia is considered as a significant risk factor of patellar instability. Different studies suggest that the shape of the trochlea is already developed in early childhood. Therefore early identification of a dysplastic configuration might be relevant information for the treating physician. An easy applicable routine screening of the trochlea is yet not available. The purpose of this study was to establish and evaluate a screening method for femoro-patellar dysplasia using 3D ultrasound. From 2012 to 2013 we prospectively imaged 160 consecutive femoro-patellar joints in 80 newborns from the 36th to 61st gestational week that underwent a routine hip sonography (Graf). All ultrasounds were performed by a pediatric radiologist with only minimal additional time to the routine hip ultrasound. In 30° flexion of the knee, axial, coronal, and sagittal reformats were used to standardize a reconstructed axial plane through the femoral condyle and the mid-patella. The sulcus angle, the lateral-to-medial facet ratio of the trochlea and the shape of the patella (Wiberg Classification) were evaluated. In all examinations reconstruction of the standardized axial plane was achieved, the mean trochlea angle was 149.1° (SD 4.9°), the lateral-to-medial facet ratio of the trochlea ratio was 1.3 (SD 0.22), and a Wiberg type I patella was found in 95% of the newborn. No statistical difference was detected between boys and girls. Using standardized reconstructions of the axial plane allows measurements to be made with lower operator dependency and higher accuracy in a short time. Therefore 3D ultrasound is an easy applicable and powerful tool to identify trochlea dysplasia in newborns and might be used for screening for trochlea dysplasia.

Acetabular defect reconstruction in revision hip arthroplasty with a modular revision system and biological defect augmentation.

PURPOSE: Revision of failed total hip arthroplasty with severe acetabular bone loss represents a rare but challenging problem. Anatomic reconstruction with biological defect augmentation as solid bone transplants or cancellous bone restores bone stock while providing good component stability. The objective of this study was to present short- to mid-term results of revision total hip arthroplasty with a modular ring system in a consecutive series of patients with severe acetabular bone loss. METHODS: We retrospectively reviewed 39 consecutive patients (39 hips) with severe acetabular bone loss (Paprosky type 3 A and 3 B) reconstructed with revision total hip arthroplasty using the cementless modular ring system MRS-Titan®. The MRS-Titan® consists of independent ring systems that are adapted modularly to the defect situation. Combined with acetabular defect reconstruction by using cancellous bone in impaction grafting technique, the MRS-Titan® system offers a cement-free revision system that enables defect-adapted customization to individual anatomic matters, bridging of the acetabular bone defect and reconstruction of the centre of rotation. Initial stability of the implant was obtained by screw fixation. Harris hip score and sequential radiographs were used to evaluate clinical and radiographic results. RESULTS: At an average follow up of 31 months (range 12-69 months) 33 of 39 (84.6 %) of the implants were considered radiographically stable without signs of acetabular migration of more than 2 mm in the horizontal or vertical direction, implant rotation or screw breakage. Complications included six implant failures (15 %). We recorded one aseptic loosening of the MRS prosthesis after 20 months. Five patients (12.8 %) had to undergo revision surgery because of periprosthetic joint infection. Two patients had a dislocation postoperatively. The mean Harris hip score improved from 27 ± 14 points preoperatively to 76 ± 15 points at the time of last follow up. CONCLUSION: By achieving stable implant fixation and providing potential for biological fixation, treatment of severe acetabular bone loss in revision total hip arthroplasty with the modular ring system MRS-Titan provides a durable solution with good clinical and radiographic results and allows us to accomplish major goals of reconstruction.

Management of severe periacetabular bone loss combined with pelvic discontinuity in revision hip arthroplasty.

PURPOSE: Revision of failed total hip arthroplasty with massive acetabular bone loss resulting in pelvic discontinuity represents a rare but challenging problem. The objective of this study was to present short to mid-term results of revision total hip arthroplasty with a custom-made acetabular implant in a consecutive series of patients with pelvic discontinuity. METHODS: We retrospectively reviewed 18 consecutive patients with massive acetabular bone loss (Paprosky Type 3B) resulting in pelvic discontinuity reconstructed with revision total hip arthroplasty using a custom-made acetabular component. The prosthesis was created on the basis of a thin-cut 1-mm computed tomography (CT) scan of the pelvis. Initial stability of the implant was obtained by screw fixation. Harris hip score and sequential radiographs were used to evaluate the clinical and radiographic results. RESULTS: At an average follow up of 30 months (range 17-62 months) 16 of 18 (88.9%) custom-made implants were considered radiographically stable without signs of acetabular migration of more than 2 mm in the horizontal or vertical direction, implant rotation or screw breakage. Complications included two periprosthetic joint infections treated with explantation of the implant. Three patients had recurrent dislocations postoperatively. The mean Harris hip score improved from 28 ± 12 points preoperatively to 69 ± 13 points at the time of last follow up. CONCLUSION: Treatment of acetabular bone loss and pelvic discontinuity with a custom-made acetabular component can provide a durable solution with good clinical and radiographic results.

Evidence of MRSE on a gentamicin and vancomycin impregnated polymethyl-methacrylate (PMMA) bone cement spacer after two-stage exchange arthroplasty due to periprosthetic joint infection of the knee.

BACKGROUND: Periprosthetic joint infections (PJI) are often treated by two stage exchange with the use of an antibiotic impregnated spacer. Most of the two-stage exchange algorithms recommend the implantation of an antibiotic-impregnated spacer during the first stage for a period of 2-24 weeks before reimplantation of the new prosthesis. For the spacer to have a therapeutic effect, the local antibiotic concentration must be greater than the minimal inhibition concentration (MIC) against the pathogens causing the PJI. It must remain so for the entire spacer period, otherwise recurrence of infection or resistances might occur. The question as to whether a sufficient concentration of antibiotics in vivo is reached for the entire spacer period has not been answered satisfactorily. CASE PRESENTATION: We here present a case of a histologically confirmed chronic PJI 20 month after primary arthroplasty. The primary knee arthroplasty was performed due to osteoarthritis of the joint. Initial assessment did not detect a causative pathogen, and two stage exchange with a vancomycin-gentamycin impregnated spacer was performed. At the time of reimplantation, sonication of the explanted spacer revealed a multi-resistant strain of staphylococcus epidermidis on the device and in the joint. Adaption of the therapy and prolonged treatment successfully eradicated the infection. CONCLUSION: According to the authors' knowledge, the case presented here confirms for the first time the surface contamination (proven through sonication) of a vancomycin-/gentamicin- impregnated Vancogenx®-spacer with a MRSE after ten weeks of implantation.This case study demonstrates the difficulties still associated with the diagnostics of PJI and the published different two stage treatment regimes with the use of antibiotic impregnated spacers.

The cement prosthesis-like spacer: an intermediate halt on the road to healing.

BACKGROUND: Periprosthetic infections remain a devastating problem in the field of joint arthroplasty. In the following study, the results of a two-stage treatment protocol for chronic periprosthetic infections using an intraoperatively molded cement prosthesis-like spacer (CPLS) are presented. METHODS: Seventy-five patients with chronically infected knee prosthesis received a two-stage revision procedure with the newly developed CPLS between June 2006 and June 2011. Based on the microorganism involved, patients were grouped into either easy to treat (ETT) or difficult to treat (DTT) and treated accordingly. Range of motion (ROM) and the knee society score (KSS) were utilized for functional assessment. RESULTS: Mean duration of the CPLS implant in the DTT group was 3.6 months (range 3-5 months) and in the ETT group 1.3 months (range 0.7-2.5 months). Reinfection rates of the final prosthesis were 9.6% in the ETT and 8.3% in the DTT group with no significant difference between both groups regarding ROM or KSS (P = 0.87, 0.64, resp.). CONCLUSION: The results show that ETT patients do not necessitate the same treatment protocol as DTT patients to achieve the same goal, emphasizing the need to differentiate between therapeutic regimes. We also highlight the feasibility of CLPS in two-stage protocols.