Comparison of Mid-Infrared Handheld and Benchtop Spectrometers to Detect Staphylococcus epidermidis in Bone Grafts.

Bone analyses using mid-infrared spectroscopy are gaining popularity, especially with handheld spectrometers that enable on-site testing as long as the data quality meets standards. In order to diagnose Staphylococcus epidermidis in human bone grafts, this study was carried out to compare the effectiveness of the Agilent 4300 Handheld Fourier-transform infrared with the Perkin Elmer Spectrum 100 attenuated-total-reflectance infrared spectroscopy benchtop instrument. The study analyzed 40 non-infected and 10 infected human bone samples with Staphylococcus epidermidis, collecting reflectance data between 650 cm-1 and 4000 cm-1, with a spectral resolution of 2 cm-1 (Agilent 4300 Handheld) and 0.5 cm-1 (Perkin Elmer Spectrum 100). The acquired spectral information was used for spectral and unsupervised classification, such as a principal component analysis. Both methods yielded significant results when using the recommended settings and data analysis strategies, detecting a loss in bone quality due to the infection. MIR spectroscopy provides a valuable diagnostic tool when there is a tissue shortage and time is of the essence. However, it is essential to conduct further research with larger sample sizes to verify its pros and cons thoroughly.

Mid-Term Migration Behavior of an Uncemented Proximally Anchored Straight Stem-A Retrospective EBRA Migration Analysis.

BACKGROUND: Aseptic loosening is one of the most-common causes of the failure of cementless stems. Einzel Bild Röntgen Analyse-Femoral Component Analysis (EBRA-FCA) allows the diagnosis of stem migration, which can be considered a factor in predicting implant survival. The current study aimed to present the migration behavior of a tapered proximally anchored straight stem. METHODS: This retrospective study reviewed all consecutive patients who received a cementless CBC straight stem (Mathys AG, Bettlach, Switzerland) between 2005 and 2019. We analyzed the migration pattern using the EBRA-FCA software and reviewed their medical histories. In addition, periprosthetic radiolucency was rated according to the Gruen zones and femoral configuration according to Dorr. RESULTS: A total of 333 stems in 332 patients (female 191; male 141) met our inclusion criteria. The mean age at surgery was 63 (range 21-87) years. Migration analysis by EBRA-FCA showed a mean subsidence of 1.6 mm at final follow-up at 96 months with a maximum noted mean subsidence of 2.0 mm at 72 and 84 months. Dorr Type A showed a tendency of less subsidence than did Dorr Type B and was statistically significant at 6 (p = 0.0396) and 72 months (p = 0.0127). The body mass index (BMI) and increased subsidence were not found to correlate (p > 0.05). For this cohort, the overall femoral revision-free rate was 95.2% and the revision-free rate for aseptic loosening was 99.1%. CONCLUSIONS: The results showed migration behavior in cementless stems with initial increased migration and subsequent secondary stabilization, suggesting an excellent long-term outcome. Stem migration of this tapered proximally anchored stem might be lower in Dorr Type A than in Dorr Type B femurs without being statistically significant at all time points.

Midterm Results of High-Dose-Rate Intraoperative Brachytherapy in the Treatment of Soft Tissue Sarcomas.

INTRODUCTION: According to the literature only sparse data are available on the use of high-dose-rate intraoperative brachytherapy (IOHDR-BT) as a boost to external-beam irradiation (EBRT) in combination with a wide resection in patients with high-grade soft tissue sarcomas (STS). MATERIALS AND METHODS: Applying a retrospective study design, we investigated all patients who between 2010 and 2016 underwent marginal resection of a high-grade STS and intraoperative radiotherapy, followed by EBRT. We included only patients with a traceable follow-up time of at least two years. Of 89 patients, 35 met our inclusion criteria and showed an average follow-up of four years. RESULTS: We found an overall 2-year local control rate of 94.3%. The local recurrence rate for R0 resections was 6%, whereas recurrences occurred in 13% of R1 resections and in 100% of R2 resections. One affected patient received only intraoperative radiotherapy. The recurrence rate by tumour entity was 36% for LPS, 11% for myxofibrosarcoma and 17% for undifferentiated pleomorphic sarcoma. CONCLUSION: The treatment regimen consisting of limb-preserving surgery, IORT and pre- or postoperative radiotherapy consistently shows excellent local control rates.

Morphological and Tissue Characterization with 3D Reconstruction of a 350-Year-Old Austrian Ardea purpurea Glacier Mummy.

Glaciers are dwindling archives, releasing animal mummies preserved in the ice for centuries due to climate changes. As preservation varies, residual soft tissues may differently expand the biological information content of such mummies. DNA studies have proven the possibility of extracting and analyzing DNA preserved in skeletal residuals and sediments for hundreds or thousands of years. Paleoradiology is the method of choice as a non-destructive tool for analyzing mummies, including micro-computed tomography (micro-CT) and magnetic resonance imaging (MRI). Together with radiocarbon dating, histo-anatomical analyses, and DNA sequencing, these techniques were employed to identify a 350-year-old Austrian Ardea purpurea glacier mummy from the Ötztal Alps. Combining these techniques proved to be a robust methodological concept for collecting inaccessible information regarding the structural organization of the mummy. The variety of methodological approaches resulted in a distinct picture of the morphological patterns of the glacier animal mummy. The BLAST search in GenBank resulted in a 100% and 98.7% match in the cytb gene sequence with two entries of the species Purple heron (Ardea purpurea; Accession number KJ941160.1 and KJ190948.1) and a 98% match with the same species for the 16 s sequence (KJ190948.1), which was confirmed by the anatomic characteristics deduced from micro-CT and MRI.

Enhancing Bone Infection Diagnosis with Raman Handheld Spectroscopy: Pathogen Discrimination and Diagnostic Potential.

Osteomyelitis is a bone disease caused by bacteria that can damage bone. Raman handheld spectroscopy has emerged as a promising diagnostic tool for detecting bone infection and can be used intraoperatively during surgical procedures. This study involved 120 bone samples from 40 patients, with 80 samples infected with either Staphylococcus aureus or Staphylococcus epidermidis. Raman handheld spectroscopy demonstrated successful differentiation between healthy and infected bone samples and between the two types of bacterial pathogens. Raman handheld spectroscopy appears to be a promising diagnostic tool in bone infection and holds the potential to overcome many of the shortcomings of traditional diagnostic procedures. Further research, however, is required to confirm its diagnostic capabilities and consider other factors, such as the limit of pathogen detection and optimal calibration standards.

EBRA Migration Analysis of a Modular, Distally Fixed Stem in Hip Revision Arthroplasty: A Clinical and Radiological Study.

Background: Massive osteolysis of the proximal femur makes stem revision a challenging procedure. EBRA-FCA provides the opportunity to determine stem migration, which is considered a predictive factor for implant survival. In this study, we aimed to analyze the migration behavior of a modular, distally fixed reconstruction prosthesis. Methods: Applying a retrospective study design, we reviewed all consecutive patients who received a cementless MP reconstruction prosthesis (Waldemar Link GmbH & Co. KG, Hamburg, Germany) at our Department between 2005 and 2019. We reviewed medical histories and performed radiological measurements using EBRA-FCA software. Results: A total of 67 stems in 62 patients (female 26; male 36) fulfilled our inclusion criteria. Mean age at surgery was 68.0 (range 38.7−88.44) years. EBRA migration analysis showed a median subsidence of 1.6 mm (range 0.0−20.6) at 24 months. The angle between stem and femur axis was 0.3° (range 0.0°−2.9°) at final follow-up. No correlation between body mass index and increased subsidence was found (p > 0.05). Overall revision-free rate amounted to 92.5% and revision-free rate for aseptic loosening to 98.5%. Furthermore, no case of material breakage was detected. Conclusions: In summary, the MP reconstruction prosthesis showed low subsidence and reduction in the migration rate over the investigated follow-up. Based on this, the modular stem can be considered as a good therapy option in challenging stem revisions offering various options to address the individual anatomical situation.

Characterizing the Mechanical Behavior of Bone and Bone Surrogates in Compression Using pQCT.

Many axial and appendicular skeleton bones are subjected to repetitive loading during daily activities. Until recently, the structural analysis of fractures has been limited to 2D sections, and the dynamic assessment of fracture progression has not been possible. The structural failure was analyzed using step-wise micro-compression combined with time-lapsed micro-computed tomographic imaging. The structural failure was investigated in four different sample materials (two different bone surrogates, lumbar vertebral bodies from bovine and red deer). The samples were loaded in different force steps based on uniaxial compression tests. The micro-tomography images were used to create three-dimensional models from which various parameters were calculated that provide information about the structure and density of the samples. By superimposing two 3D images and calculating the different surfaces, it was possible to precisely analyze which trabeculae failed in which area and under which load. According to the current state of the art, bone mineral density is usually used as a value for bone quality, but the question can be raised as to whether other values such as trabecular structure, damage accumulation, and bone mineralization can predict structural competence better than bone mineral density alone.

Aerosol morphology and particle size distribution in orthopaedic bone machining: a laboratory worst-case contamination simulation. Is high-speed bone machining potentially harmful by pollution and quality schemes and what measures could be taken for prevention?

AIM OF THE STUDY: High-speed bone machining devices with irrigation fluid were used in surgery to spread aerosols and toss tissue particles of varying morphology into the operating room. Based on measurements taken on a phantom object, the shape, size, and spatial contamination distribution of such particles were assessed. METHOD: Cadaveric femoral heads were continuously machined with a spherical bur, manually held at a fixed attack angle. The irrigation fluid used during bone machining was enriched with bacteria to act as a tracer to quantify the spatial contamination. A vertical board equipped with snippets served as a phantom object to assess contamination load and morphology of airborne particles. RESULTS: Eight-nine percent of the particles had a non-circular cross section. The detected particle size ranged across six orders of magnitude, from 0.006 to 4 mm2 with a median particle size of 0.125 mm2. The CFU counts observed after the standard machining time ranged from 7 to 240, with a median of 2 CFUs. The highest median contamination was seen at the upper right corner of the phantom. DISCUSSION: The experiments show that contaminating particles of a wide variety of shapes and sizes are part of the aerosol created by high-speed burring. While protection of personnel and equipment is always important, surgical helmets should be worn, especially at contamination hotspots, and gloves should be replaced at the end of machining. Sensitive instruments and measuring devices-such as optical sensors-should also be protected effectively, as the optical measurement may be obstructed by aerosol particles.

Correlation of Loss of Correction With Postoperative Radiological Factors After Distal Chevron Osteotomy in Dependence of Concomitant Akin Osteotomy.

Loss of correction is frequently observed following hallux valgus correction and is associated with recurrence of a hallux valgus deformity. The purpose of this study was to correlate loss of correction and radiological parameters following distal chevron (Group C) and combined chevron/akin (Group AC) osteotomy. A total of 859 feet were included for analysis and grouped according to treatment with a distal chevron osteotomy alone or a combined chevron/akin osteotomy. Radiographs were evaluated preoperatively, postoperatively, after 6 weeks, 3 months and, if available, at long term follow-up with a mean of 34.2 (range 7.5-155.3) months. With the exception of the proximal to distal phalangeal articular angle (PDPAA), preoperative deformity was comparable between both groups. Significant correction of all examined parameters (p < .001) was seen. Loss of correction at 6 weeks with minor deterioration until follow-up was also detected, with group AC somewhat better than Group C. A strong correlation with loss of correction was found for the postoperative hallux valgus angle (HVA) (p < .002), intermetatarsal angle (IMA) (p < .001), distal metatarsal articular angle (DMAA) (p < .002), positioning of the sesamoids (p < .002) and joint congruity (p < .035) in Group C and for the DMAA (p < .033) and HVA (p < .046) in Group AC. Multiple postoperative radiological parameters correlated with loss of correction following distal chevron osteotomy. In Group AC only postoperative HVA and DMAA determined loss of correction. Correction of the deformity in Group AC showed greater stability.

Migration characteristics of the Corail hydroxyapatite-coated femoral stem-a retrospective clinical evaluation and migration measurement with EBRA.

PURPOSE: Uncemented stem migration analysis by EBRA-FCA (Einzel-Bild-Roentgen Analyse, Femoral Component Analysis) has been seen to be a good predictive indicator for early implant failure. In this study, we investigated the migration behavior of a cementless press-fit stem after two years follow-up. Stem type and postoperative gap between collar and femur were evaluated as a risk factor. METHODS: Applying a retrospective study design, we reviewed all consecutive patients who between 2013 and 2017 received a cementless press-fit Corail stem (DePuy Orthopaedics Inc., Warsaw, IN, USA) at our Department. We reviewed medical histories and performed radiological measurements using EBRA-FCA software. RESULTS: A total of 109 stems in 105 patients (female: 60; male: 45) fulfilled our inclusion criteria. Mean age at surgery was 67.8 (range, 21.6-90.5) years. EBRA migration analysis showed a mean subsidence of 1.8 mm (range, 0.0-12.1) at final follow-up. At 18 months mean subsidence of collared stems was significantly lower than in the collarless group [1.3 mm (range, 0.0-7.6) vs. 3.2 mm (range, 0.5-10.7), p = 0.0104]. Collared stems resting on the femoral cut presented a tendency to less subsidence than did collared stems showing a postoperative gap between collar and femur (1.3 vs. 2.0 mm) without finding statistical significance (p > 0.05). CONCLUSIONS: Low subsidence and the migration pattern of the cementless press-fit stem may predict a good long-term result. Collared stems investigated in our study provide good stability and are able to prevent significant subsidence. Trial registration number and date of registration: Number: 20181024-1875; Date: 2018-10-24.

The effect of gastrocnemius resection on knee flexion in a total knee arthroplasty model.

INTRODUCTION: Flexion contracture in knee arthritis and total knee arthroplasty (TKA) is a common and significant problem. An improvement in knee extension in patients with TKA and mild flexion contractures has been observed clinically when a gastrocnemius recession was performed for other concomitant conditions. The goal of this study was to quantify the effect of gastrocnemius recession on knee flexion in TKA cadaver model. MATERIALS AND METHODS: Range of motion (ROM) of 23 cadaveric knees was determined with a navigation system before and after performing TKA using a medial parapetallar approach and after performing a gastrocnemius recession. Varus-valgus, flexion-extension, and internal-external rotation angles of the knee joint were recorded with leg in full extension and in 90°of knee flexion. Extension and flexion gaps were measured using a gap tensioning device. Dorsiflexion of the foot was measured with a goniometer when a torque moment of 10 Nm was applied to the ankle joint. RESULTS: A statistically significant improvement of 5° in knee extension was observed following gastrocnemius recession (P = 0.015). Varus and valgus angles, internal, and external rotation were unaffected by gastrocnemius recession. Ankle dorsiflexion increased by 9° following gastrocnemius recession (P ≤ 0.001). CONCLUSIONS: Performing a gastrocnemius recession improves the knee extension in TKA knees with flexion contractures. Gastrocnemius recession may be a useful technique to improve terminal extension in TKA.

Subsidence of a metaphyseal-anchored press-fit stem after 4-year follow-up: an EBRA-FCA analysis.

PURPOSE: Uncemented stem migration analysis by EBRA-FCA (Einzel-Bild-Roentgen Analyse, Femoral Component Analyse) has been seen to be a good predictive indicator for early implant failure. In this study, we investigated the migration behavior of a cementless metaphyseal-anchored press-fit stem after 4-year follow-up. METHODS: Applying a retrospective study design, we reviewed all consecutive patients who between 2012 and 2017 received a cementless Accolade II press-fit stem at our Department. We reviewed medical histories and performed radiological measurements using EBRA-FCA software. EBRA-FCA measurements and statistical investigations were performed by two independent investigators. RESULTS: A total of 102 stems in 91 patients (female 60; male 31) fulfilled our inclusion criteria. Mean age at surgery was 66.2 (range 24.3-92.6) years. EBRA migration analysis showed a mean subsidence of 1.4 mm (range 0.0-12.0) at final follow-up. The angle between stem and femur axis was 0.5° (range 0.0°-2.8°) after 48 months. No correlations between gender or Dorr types and subsidence were found (p > 0.05). A body mass index > 30 kg/m2 showed a significant increase in stem subsidence within the first 6 (p = 0.0258) and 12 months (p = 0.0466) postoperative. CONCLUSIONS: Migration pattern of the metaphyseal-anchored stem and a low subsidence rate at final follow-up may predict a good long-term clinical result. TRIAL REGISTRATION: Number: 20181024-1875.

A Prospective Assessment of Knee Arthroscopy Skills Between Medical Students and Residents-Simulator Exercises for Partial Meniscectomy and Analysis of Learning Curves.

BACKGROUND: The Covid-19 pandemic has created the largest disruption of education in history. In a response to this, we aimed to evaluate the knee arthroscopy learning curve among medical students and orthopaedic residents. METHODS: An arthroscopy simulator was used to compare the learning curves of two groups. Medical students with any prior knowledge of arthroscopy (n=24) were compared to a residents group (n=16). Analyzed parameters were "time to complete a task," assessment of the movement of tools and values scoring damage to the surrounding tissues. RESULTS: After several repetitions, both groups improved their skills in terms of time and movement. Residents were on average faster, had less camera movement, and touched the cartilage tissue less often than did students. Students showed a steeper improvement curve than residents for certain parameters, as they started from a different experience level. CONCLUSION: The participants were able to reduce the time to complete a task. There was also a decrease in possible damage to the virtual surrounding tissues. In general, the residents had better mean values, but the students had the steeper learning curve. Particularly less experienced surgeons can especially train their hand-eye coordination skills required for arthroscopy surgery. Training simulators are an important training tool that supplements cadaveric training and participation in arthroscopic operations and should be included in training.

Mechanical and Morphological Assessment of an Innovative Textile for Patient Positioning Applications: Comparison to Two Standard Bandage Systems.

In the healthcare environment, bandage systems are versatile medical devices to position and fix patients' torsos or extremities. In this study, the mechanical and morphological properties of an innovative patient position system, iFix, were assessed and compared to two commercially available bandages. Morphological properties were investigated using a scanning electron microscope (SEM). The iFix bandage showed anisotropic mechanical properties, with a more rigid behavior in the longitudinal direction and a more elastic behavior in the transverse direction. This behavior results from the organization of the fibers visible in the SEM images. All three materials investigated in this study were able to support similar maximum loads. In cases where a rigid fixation of patient limbs or torso is necessary, the authors recommend the usage of iFix. In vivo studies should be carried out to prove safety in a surgical environment before its clinical usage.

Impact of the Covid-19 Pandemic on Orthopaedic and Trauma Surgery - A Systematic Review of the Current Literature.

BACKGROUND/AIM: The Coronavirus disease 2019 (COVID-19) has led to significant disruptions in various medical specialties. We herein aimed to provide a systematic review of the published literature on the impact by the Covid-19 pandemic on orthopaedic and traumatological care by focusing on the number of clinical visits, surgeries and reasons for consultation. MATERIALS AND METHODS: The published literature was reviewed using PubMed. Of 349 studies published between December 1, 2019 and October 1, 2020, 36 original articles met the inclusion criteria. Articles were selected on the basis of the PRISMA guidelines. October 1, 2020 was used as the concluding date of publication. RESULTS: The number of elective visits declined by 50.0% to 74.0%. The number of emergency and trauma visits showed a decrease of 37.7% to 74.2%. Trauma surgery decreased by 21.2% to 66.7% and elective surgeries by 33.3% to 100%. CONCLUSION: Orthopaedic and trauma surgery is clearly influenced by the pandemic. It will be important to maintain treatment and surgical care of patients in order to avoid negative effects on treatment progress.

The spatial distribution of aerosols in high-speed bone burring with external irrigation.

It is well-known that the use of high-speed burring devices with irrigation used in bone surgery produces aerosols, and can toss tissue particles into space. The aim of this study was to assess the spatial vertical contamination in the sterile operation field while using a high-speed cutting device at various locations. A fresh porcine knee was resected for 10 min with a high-speed burring device. To determine the spatial contamination distribution bacteria were used as a tracer. In this novel method for detecting environmental contamination droplets of the contaminated irrigation solution were collected on vertically mounted Petri dishes and the number of colony-forming units was counted. Contamination of varying intensity was observed throughout the room. The highest contamination was found perpendicular to the bur rotation axis in a distance 0.5 m from the bur, at a height of 1.4 m. Around this spot, colony-forming units count isotropically drops to less than 100 CFUs at an area of 0.5 m in diameter. The contamination decreases with increasing distance to the bur head and a main direction of contamination was identified. Placing critical sterile objects in the highly contaminated space during and after bone resection procedures should be avoided whenever possible.

Multiple Intraosseous Lipomatosis - A Case Report and a Review of the Literature.

BACKGROUND: Intraosseous lipomatosis is a rare and uncommon entity with only a few cases reported in the literature. CASE REPORT: We report a severe case where post-traumatic radiographs showed multiple cystic osseous lesions and a pathological fracture. The findings were expanded with whole-body magnetic resonance imaging (MRI), which showed multiple osseous lesions with typical MRI characteristics of intraosseous lipomas. CONCLUSION: Our case, together with very few other cases described in the literature, emphasizes that multiple intraosseous lipomatosis is an important differential diagnosis for multiple radiolucent lesions on plain radiographs. Multiple intraosseous lipomatosis can lead to pathological fractures and severe impairment of life quality. The presence of well-defined, osteolytic lesions in the bone calls for an MRI or computed tomography scan.

Twenty-one sports activities are recommended by the European Knee Associates (EKA) six months after total knee arthroplasty.

PURPOSE: To elaborate recommendations for sports participation following TKA among the members of the European Knee Associates (EKA). METHODS: A prospective online survey was conducted among the members of the European Knee Associates (EKA). The European Knee Associates (EKA) are a section of the European Society of Sports Traumatology, Knee Surgery and Arthroscopy (ESSKA). The survey investigated recommendations for 47 sports disciplines. Possible answers were: allowed, allowed if experienced, not allowed, no opinion. The survey was conducted separately for 4 specific time frames: within 6 weeks after TKA; 6-12 weeks after TKA; 3-6 months after TKA; and more than 6 months after TKA. Consensus among the respondents was then analyzed. RESULTS: EKA members (N = 120) participated in the survey. A high level of consensus was reached for a recommendation to allow 5 different sports in the first 6 weeks after TKA, 7 sports 6-12 weeks after surgery, 14 sports 3-6 months after TKA, and 21 out of 47 activities 6 months after surgery. In the first 6 weeks after TKA walking, stair climbing, swimming, aqua fitness, and static cycling were recommended. Six to twelve weeks after TKA, cycling on level ground and yoga were recommended in addition to the aforementioned activities. Further sports activities recommended beyond 12 weeks after TKA were: tennis doubles, golf, fitness/weight lifting, aerobics, hiking, Nordic walking and sailing. The sport for which the recommendation was "not allowed" following TKA was squash. CONCLUSION: The number of sports recommended by EKA surgeons increases stepwise over the postoperative time frames. The findings are regarded as clinically relevant as they may serve as a basis for answering patient questions on timing and giving recommendations for the resumption of sports activities following standard primary TKA and should be individualized by surgeons for their patients' expectations and goals. LEVEL OF EVIDENCE: V.

Two-year radiologic assessment of the Pinnacle cup-a migration analysis with EBRA.

INTRODUCTION: The most common cause of failure in total hip arthroplasty (THA) is aseptic loosening. Uncemented cup migration analysis by EBRA (Einzel-Bild-Roentgen-Analyse) has shown to be a good predictive indicator for early implant failure if the cup migrates more than 1 milimeter (mm) within the first 2 years after surgery. In this study, we investigated the migration behaviour of an uncemented press-fit cup after 2 years follow-up. MATERIALS AND METHODS: Applying a retrospective study design, we reviewed all consecutive patients who received an uncemented press-fit cup at our Department between 2013 and 2018. A total of 484 patients were identified. We reviewed medical histories and performed radiological measurements using EBRA-Cup software. EBRA measurements and statistical investigations were performed by two independent investigators. RESULTS: A total of 165 cups in 159 patients (female: 90; male: 69) met our inclusion criteria. Mean age at surgery was 66.7 (range 18.4-90.5) years. EBRA migration analysis showed a mean total migration of 0.7 mm (range 0.0-6.3) over our follow-up period of 2 years. Of the investigated cups, 53.2% showed less than 1 mm migration in the investigated follow-up period. CONCLUSION: In conclusion, the Pinnacle cup used in our study provides low mean migration at final follow-up. Based on the assumption of secondary stabilization, good long-term outcome of the Pinnacle cup can be expected. TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION: Number: 20181024-1875; Date: 2018-09-20.

Outcome and EBRA migration analysis of a reconstruction cage in acetabular revision arthroplasty: a clinical and radiological study.

PURPOSE: Restoration cages and bone allografts have been proposed to manage severe acetabular bone defects. We aimed to investigate the migration behaviour of a restoration cup and impacted allograft bone in severe acetabular defects with Einzel-Bild-Röntgen-Analyse (EBRA). METHODS: Applying a retrospective study design, 64 cases treated between 2009 and 2016 were reviewed. We determined the preoperative Charlson Comorbidity Index (CCI), pre- to postoperative WOMAC score, blood loss and functional outcome. From preoperative x rays, the acetabular deficiencies were classified according to Paprosky. Cup migration analyses were performed with EBRA. RESULTS: Mean age at surgery was 73 (range: 38-93) years. According to the classification by Paprosky et al., 50% (n = 32) of our patients showed a type III B and 28.1% (n = 18) a type III A defect. Radiological follow-up for migration analysis was 35 (range: 4-95) months. Migration analysis showed a mean cup migration of 0.7 mm (range: 5.7-9.6) medial and 1.8 mm (range: 1.7-12.6) cranial. CONCLUSION: In conclusion, acetabular restoration cages in combination with bone impaction grafting showed a low revision rate at a mean follow-up of 35 months. Mean cup migration revealed low rates after 2 years and suggested a stable postoperative implant position.