Prolonged suppressive antibiotic therapy is successful in the management of prosthetic joint infection.

INTRODUCTION: Prosthetic joint infection (PJI) remains one of the major challenges facing orthopaedic surgeons. There is a paucity of evidence on non-operative management of PJI. We present the results of prolonged antibiotic suppression therapy (PSAT) in PJI from a single centre. METHODS: A retrospective study was performed. Twenty-six patients were included. Two patients were excluded due to the lack of follow-up data. Failure was defined as admission for sepsis from the joint or amputation. RESULTS: Average age was 72 years (range 35-93). Mean Charlson co-morbidity index was 4.3. Mean follow-up was 3.2 years (range 1.3-5.7). Staphylococcal species were isolated in 11 cases (44%) (MRSA 1, MSSA 5, Staph. epidermidis 4 and Staph Pasteuri 1). Other bacteria included E. Coli (2), Streptococci spp. (3), Propionebacterium acnes (1) and Pseudomonas aeruginosa (1). Four cases were polymicrobial infection (16%), and no organisms were identified in two cases (8%). Candida albicans was identified in one case. All cases of bacterial infection were treated with prolonged oral doxycycline or amoxicillin. Twenty patients (80%) received 6 weeks of intravenous antibiotics prior to commencing prolonged oral antibiotics. Two patients experienced persistent symptoms and required amputation (both TKA). Two patients experienced sepsis but were treated successfully with IV antibiotics alone. The success rate of PSAT was 84% (21/25) successful at an average 3.2-year follow-up. DISCUSSION AND CONCLUSION: Prolonged suppressive antibiotic therapy is a viable option for the management of PJI with a low incidence of complications.

[Revision arthroplasty : Histopathological diagnostics in periprosthetic joint infections]. / Revisionsendoprothetik : Infektionsdiagnostik und Histopathologie.

BACKGROUND: Histopathological differences in synovia and synovial-like interface membrane (SLIM) patterns can be used to differentiate periprosthetic particle-induced reactions, bacterial infections (bacterial synovitis and osteomyelitis), mechanical-induced tissue alterations, adverse reactions to implant material, and arthrofibrosis (SLIM consensus classification). AIM: Because of differences in treatment the diagnosis of a bacterial implant infection is very important. Histopathological tests and scoring systems are important diagnostic tools in identifying deep implant infections in patients with unclear clinical history as well as radiographic and laboratory studies. RESULTS: Modern enzyme PCR-based methods, histochemical- and immune-histopathological techniques (CD3,CD15, CD68) are useful in identifying specific and nonspecific infections, as well as differentiating postsurgical changes from recurrent infections in patients with a spacer. In all histopathological scoring systems for bacterial infection, quantifying the number of neutrophil granulocytes in a defined number of high power fields is crucial. DISCUSSION: Neutrophil granulocytes can be detected through histochemical methods and more specifically by immune-histopathological techniques and by various quantification systems (histopathological scores) leading to the diagnosis of bacterial peri-implant infection. One important function of histopathology, apart from diagnosing infection, is to rule out other mechanisms of implant failure, such as tumor infiltrations, particle-induced reactions, and adverse reactions to implant materials.

[CD15 focus score for diagnostics of periprosthetic joint infections : Neutrophilic granulocytes quantification mode and the development of morphometric software (CD15 quantifier)]. / CD15-Fokus-Score zur Diagnostik der periprothetischen Gelenkinfektion : Neutrophile-Granulozyten-Quantifizierungs-Modus und Entwicklung einer morphometrischen Software ("CD15-Quantifier").

BACKGROUND: The aim of this project was to devise a quantification method for neutrophils within a single focal point through the development of a CD15 focus score which enables bacterial infections in synovial-like interface membranes (SLIM) to be diagnosed. METHODS: In this study a histopathological classification of 91 SLIM removed during revision surgery from the hips (n = 59) and knees (n = 32) was performed. Neutrophils were identified immunohistochemically by means of a CD15-specific monoclonal antibody. The quantitative evaluation of CD15-positive neutrophils (CD15Ne) used the principle of maximum focal infiltration (focus) together with an assessment of a single focal point (0.3 mm(2)). This immunohistochemical approach made it possible to develop the CD15 quantifier software, which automatically quantifies CD15Ne. RESULTS: The SLIM cases with positive microbiological findings (n = 47) had significantly (p < 0.001, Mann-Whitney U-test) more CD15Ne/focal point than cases with negative microbiological findings (n = 44). A count of 50 CD15Ne/focal point was identified as the optimum threshold when diagnosing periprosthetic joint infections (PJI) using the CD15 focus score. If the microbiological findings are used as a gold standard, the diagnostic sensitivity is 0.83, and the specificity is 0.864 with a positive predictive value (PPV) of 0.87, a negative predictive value (NPV) of 0.83, an accuracy of 0.846 and an area under the curve (AUC) of 0.878. The evaluation of findings for the preparations using the CD15 quantifier software (n = 31) deviated by an average of 12 cells from the histopathological evaluation findings (CD15 focus score). Above a cell count of 62, the CD15-quantifier needs on average 32 s less than the pathologist. CONCLUSION: The immunohistochemical CD15 focus score has a high diagnostic value and allowed the development of the CD15 quantifier software. This provides an automated procedure, which shortens the mentally tiring and time-consuming process of microscopic cell counting and thus makes a contribution towards the standardization of tools for diagnosing PJI.

[Histopathological differential diagnostics in context of joint implant allergic reactions]. / Histopathologische Differenzialdiagnostik bei gelenkimplantatallergischen Fragestellungen.

Total joint replacement has greatly increased over the last decades and so have endoprothesis-associated pathologies. European studies have shown a 10-year durability varying from 88% to 95%. By means of histopathology different pathogenetic synovial-like interface membrane (SLIM) patterns that lead to reduction of implant durability can be discerned, such as periprosthetic particles, bacterial infections and arthrofibrosis. Subsequently, SLIM types have been determined in a revised consensus classification including particle-induced type (type I) so-called non-septic loosening, infection type (type II) so-called septic loosening, combination type (type III) of bacterial and particle-induced types, indifferent type with mechanical and functional disorders (type IV), osseus pathologies (type V), arthrofibrotic type (type VI, endoprosthesis-associated arthrofibrosis) and allergic/immunological/toxic reactions to prosthesis material (type VII). Particles are characterized histopathologically according to the Krenn particle algorithm. In cases of severe lymphocyte/macrophage infiltration, necrosis, abrasion particle detection and granuloma formation, a toxic or allergic reaction to implant material should be considered. As a direct abrasion particle-induced toxicity cannot be differentiated from a particle-induced allergic type VII reaction to implant material, the histopathological diagnosis of toxic reaction to implant material or allergic reaction to implant material should be made with caution and only in association with immunological, allergic and clinical data. It is recommended that tissue samples should be arthroscopically taken from different regions: close to the prosthesis, distant from the prosthesis and from bone tissue. The pathologist should be given information concerning clinical, allergological and microbiological data.

[Synovialitis of the arthrofibrotic type: criteria of a new synovialitis type for the diagnosis of arthrofibrosis]. / Synovialitis vom arthrofibrotischen Typ: Kriterien eines neuen Synovialitis-Typus für die Diagnose der Arthrofibrose.

After rheumatologic conservative medical therapy has been exhausted in degenerative and inflammatory joint diseases, arthroplastic operations are an important option to restore quality of life. Endoprosthesis-associated arthrofibrosis is a severe fibrosing disease of the synovial membrane after endoprosthetic operations. Neither the morphological substrate nor histopathological criteria have been described. The aim was to describe the histopathological substrate of arthrofibrosis and to define histological and immunohistochemical criteria of arthrofibrosis on the basis of tissue samples derived from revision. In histopathological analyses arthrofibrosis revealed a synovialitis with varying fibrosis, without detectable ossification and without minimal wear particle reaction (so-called synovialitis of arthrofibrotic type, SAT). A 3-stage grading was determined based on the cellular density of the fibrous tissue (fibroblast cellularity). In 191 cases with SAT, grade 1 was found in 24.1 % (n = 46), grade 2 was found in 51.8 % (n = 99) and grade 3 was found in 24.1 % (n = 46). The control group consisted of 29 cases with synovialitis of indifferent type (type IV membrane). If SAT grades 2 and 3 are summed together, i.e. the distance between the fibroblasts was less than two cell lengths, the difference of the fibroblast cellularity compared with the type IV membrane was significant (p < 0.001). Above SAT grade 2 the diagnosis of arthrofibrosis could be made with a sensitivity 0.7592 and specificity 0.8276. The SM-alpha-actin cytoplasmic positivity of fibroblasts indicates a myofibroblast phenotype and the ß-catenin positivity suggests a resemblance to fibromatosis or a keloid-like process. In the quantitative evaluation of the ß-catenin positive fibroblasts, there was a significant difference (p < 0.001) between type IV membrane and SAT. A threshold value of 20 beta-catenin positive cells per microscopic high power field (HPF) was determined, which represents in conjunction with the clinical information a new histopathological diagnosis component (sensitivity 0.720, specificity 0.867).

[Revised consensus classification. Histopathological classification of diseases associated with joint endoprostheses]. / Erweiterte Konsensusklassifikation. Histopathologische Klassifikation von Gelenkendoprothesen-assoziierten Erkrankungen.

The revised classification of the periprosthetic membrane (synovial-like interface membrane SLIM) encompasses all pathological alterations which can occur as a result of endoprosthetic replacement of major joints and lead to a reduction in durability of prostheses. This also includes the established consensus classification of SLIM by which aseptic and septic prosthetic loosening can be subdivided into four histological types and histopathological criteria for additional pathologies: endoprosthesis-associated arthrofibrosis, immunological/allergic alterations and osseous pathologies. This revision represents the foundation for the histopathological diagnostics of the total spectrum of diseases associated with joint prostheses, is a suitable basis for a standardized diagnostic procedure and etiological clarification of endoprosthesis failure and also as a data standard for endprosthesis registers, in particular for registers based on routine data (e.g. German endoprosthesis register).

Patellofemoral kinematics in mobile-bearing and fixed-bearing posterior stabilised total knee replacements: a cadaveric study.

PURPOSE: The aim was to compare the patellar kinematics in the normal knee, fixed-bearing (FB) and mobile-bearing total knee replacement (MB-TKR). The hypothesis that a mobile-bearing TKR has a more natural patellar movement was tested. METHODS: Computer navigation was used to track the patella in nine whole lower extremities in the natural knee and in the same knee with a posterior stabilised FB-TKR and a posterior stabilised MB-TKR from 0° to 90° flexion. The form and position of the trochlea in the natural knee and the patellar groove of the TKR femoral component was also analysed. RESULTS: There were no differences between the FB and MB-TKRs. But the patella in the TKRs at flexion angles of more than 50° had a more medial tilt compared to the natural knee. The patella of the natural knee tended to rotate externally with flexion, this was not seen in both TKR types. There were no significant differences in absolute mediolateral translation nor in translation relative to the patellar groove. During flexion, the patella lost contact with its groove earlier in the TKRs. The radius of the patellar groove of the femoral component was larger. The groove extended more superiorly and less far posteriorly, it was also positioned further laterally compared to the natural knee. CONCLUSIONS: There are subtle kinematic differences in patellar tracking between the natural knee and a TKR presumably due to differences in the shape and position of the patellar groove. There are no kinematic differences in patellar movement between the FB- and MB-TKR.

[One-stage revision of knee endoprosthesis due to periprosthetic infection and Klippel-Trenaunay syndrome]. / Einzeitiger Knieendoprothesenwechsel bei periprothetischer Infektion und Klippel-Trenaunay-Syndrom.

We present the case of a patient with Klippel-Trenaunay syndrome (KTS) who underwent a one-stage revision of an infected total knee arthroplasty. A detailed orthopedic description of KT is presented as well as a discussion on the implementation of one-stage or multi-stage revision following infections of total knee arthroplasty. Due to vascular anomalies with severe coagulation problems, soft tissue swelling and increased risk of infection, surgical treatment of such patients presents a special challenge.

[Preoperative anemia in orthopedic surgery: clinical impact, diagnostics and treatment]. / Präoperative Anämie in der Orthopädie: Klinische Relevanz, Diagnostik und Therapie.

In a national audit of elective orthopedic surgery conducted in the US, 30% of patients were found to have hemoglobin (Hgb) levels < 13 g/dl at preadmission testing. Preoperative anemia has been associated with increased mortality and morbidity after surgery, increased allogeneic blood transfusion therapy and increased rates of postoperative infection leading to a longer length of hospital stay. Because of the risks associated with allogeneic blood transfusions according to German law patients have to be offered the option of autologous transfusion if the risk associated with allogeneic blood transfusion is > 10%. However, one of these measures, the autologous blood donation, can exaggerate anemia and can increase the overall transfusion rates (allogeneic and autologous). As autologous procedures (autologous blood donation and cell salvage) are not always appropriate for anemic patients together with an expected shortage of blood and because preoperative anemia is associated with perioperative risks of blood transfusion, a standardized approach for the detection, evaluation and management of anemia in this setting was identified as an unmet medical need. A panel of multidisciplinary physicians was convened by the Society for Blood Management to develop a clinical care pathway for anemia management in elective surgery patients for whom blood transfusion is an option. In these guidelines elective surgery patients should have Hgb level determination at the latest 28 days before the scheduled surgical procedure. The patient target Hgb before elective surgery should be within the normal range (normal female ≥ 120 g/l, normal male ≥ 130 g/l). Laboratory testing should take place to further determine nutritional deficiencies, chronic renal insufficiency and/or chronic inflammatory diseases. Nutritional deficiencies should be treated and erythropoiesis-stimulating agent (ESA) therapy should be used for anemic patients in whom nutritional deficiencies have been ruled out and/or corrected.

Results of total aponeurectomy for Dupuytren's contracture in 61 patients: a retrospective clinical study.

INTRODUCTION: Many surgical techniques have been advocated to treat Dupuytren's contracture. Partial fasciectomy is often performed to treat the whole spectrum of Dupuytren's disease. METHOD: We have reviewed the effectiveness of total aponeurectomy performed on 61 patients [10 women and 51 men (male:female ratio 5.1:1) with a mean age of 63.0 (range 42-79 years) and a mean follow-up of 3.45 years (range 1.03-6.39 years)]. RESULTS: Post-operative complications including haematoma, seroma or necrosis were found in 13.8% of the patients. Recurrence of contracture occurred in 10.8% of the patients and 4.6% of the operated patients presented with a nerve lesion. Nerve irritation occurred in 6.2% of the patients. The mean DASH-score was 3.85 (range 0-52.5). Family pre-disposition was an important risk factor for Dupuytren's disease with 44.3% of patients having a positive family history. CONCLUSION: We suggest that total aponeurectomy is a promising alternative to partial fasciectomy with low risk for a recurrence and slightly increased risk for a nerve lesion.

Computer-assisted antetorsion control prevents malrotation in femoral nailing: an experimental study and preliminary clinical case series.

MATERIALS AND METHODS: The effect of fluoroscopy-based navigation for femoral fracture reduction on the prevention of malrotation was examined in an experimental setting followed by a first case series. Eleven cadaver femurs were used. All femurs were reduced by closed methods. An optoelectronic navigation system was utilized to check for fragment reduction and alignment. Fluoroscopic control without navigation was used as the control group. The Six Sigma Analysis [offset capability index (C (pk)) = 1.3] was used to compare the probability of outliers of more than 15 degrees . In the clinical case series the same navigation tool was used in ten non-consecutive patients with femoral fractures. Torsional differences between both legs were measured postoperatively by CT scan. RESULTS: The highest malrotation in the navigated group was 7.0 degrees for the cadaver testings, while two femurs in the control group showed a difference of more than 10 degrees (10.3 degrees , 17.4 degrees). Only the navigated group showed a sufficient offset capability index (C (pk-navigated) = 1.83; C (pk-conventional) = 0.59). In the clinical series nine femurs were successfully reduced by navigation control. The average malrotation was 6.6 degrees . No patient had a torsional difference of more than 10 degrees. CONCLUSION: Navigated femoral nailing reduces the risk for outliers of postoperative torsional differences and might avoid revision surgery for malrotation. LEVEL OF EVIDENCE: IV.

Usefulness of a head mounted monitor device for viewing intraoperative fluoroscopy during orthopaedic procedures.

We report our case series involving the use of a MicroOptical (MicroOptical Corporation, Westwood, MA, USA) head mounted, computer display monitor during orthopaedic procedures such as open reduction and internal fracture fixations and spinal pedicle screw placement. Since the MicroOptical viewer does not fully obstruct the surgeon's direct vision, he/she may continue to operate and focus on the operative field while viewing the MicroOptical image. Our first 50 clinical applications demonstrate that when viewing the MicroOptical monitor there is a significant reduction in the total number of times the surgeon left the attention of the operative field and/or may have been exposed to fluoroscopy radiation by unprotected body turn exposure. In addition, the MicroOptical viewer did not cause any surgical field viewing obstruction during surgical procedures and there was not a difference in reported surgeon eye fatigue when comparing the MicroOptical viewer to standard fluoroscopy.

Percutaneous bone biopsy. A new application for 3D navigation: a pilot study.

Computer Tomography (CT) guided percutaneous bone biopsy has been established as a minimally invasive method for the rapidly obtaining samples from osseous lesions for histological examination. With this method, an overall accuracy of 90% can be obtained without a significant radiation exposure. The aim of this study was to develop a navigated sleeve for the Jamshidi needle in order to perform navigated, percutaneous bone biopsies with the help of Iso-C-3D. Utilizing this navigated biopsy needle, the procedure was analyzed for several parameters including precision, total operating time, and level of radiation exposure. By using the Iso-C-3D navigation the total operating time was 11.7 min (8-14.3) and radiation exposure was 1.6 (0.67-2.12 min). This study demonstrates that navigated percutaneous bone biopsies can be obtained fast and with low radiation exposure. The feasibility of Iso-C-3D navigated bone biopsies is tempered by the requirement a rigidly fixed dynamic reference frame.

Navigation in ACL reconstruction - comparison with conventional measurement tools.

Restoration of rotational and translational stability is a goal of ACL reconstruction. Intraoperative instability measurements of AP translation and rotation are not well established clinically. We compared navigated measurements of tibial AP translation and rotation with mechanical measuring devices: the KT 1000 and a modified goniometer tool. Tests were repeated with intact and dissected ACLs, and measures of translation and rotation statistically compared. There was no significant difference in AP translation between navigation, 3.2 mm (range 1-6 mm) and the KT 1000, 4.8 mm (range, 4-7 mm) in our experimental set up (p>0.05). Tibial rotation revealed no significant difference, 0.12 degrees (range, 0 degrees -1 degrees ) between navigation and goniometer (p>0.05). Total range of rotation was 4.2 degrees (range, 2 degrees -6 degrees ) in intact and 7.05 degrees (range, 4 degrees -9 degrees ) in dissected ACLs (p<0.05). Stability parameters in ACL navigation can be measured precisely under laboratory conditions and results are not significantly different from mechanical testing devices.

Reference marker stability in computer aided orthopedic surgery: a biomechanical study in artificial bone and cadavers.

INTRODUCTION: In computer assisted orthopaedic surgery, rigid fixation of the Reference Marker (RM) system is essential for reliable computer guidance. A minimum shift of the RM can lead to substantial registration errors and inaccuracies in the navigation process. Various types of RM systems are available but there is little information regarding the relative stabilities of these systems. The aim of this study was to test the rotational stability of three commonly used RM systems. MATERIALS AND METHODS: One hundred and thirty Synbones and 15 cadavers were used to test the rotational stability of three different RM systems (Schanz' screw, RM B and RM C adjustment systems). Using a specially developed testing device, the peak torque sustained by each RM system was assessed in various anatomical sites. RESULTS: Comparison of means for Synbone showed that the RM C was the most stable (mean peak torque 5.60 +/- 1.21 Nm) followed by the RM B system (2.53 +/- 0.53 Nm) and the RM A (0.77 +/- 0.39 Nm) (p<0.01). The order of stability in relation to anatomical site was femoral shaft, distal femur, tibial shaft, proximal tibia, anterior superior iliac spine, iliac crest and talus. Results from the cadaver experiments showed similar results. Bi-cortical fixation was superior to mono-cortical fixation in the femur (p<0.01) but not the tibia (p=0.22). CONCLUSION: The RM system is the vital link between bone and computer and as such the stability of the RM is paramount to the accuracy of the navigation process. In choosing RM systems for computer navigated surgery surgeons should be aware of their relative stability. Anatomical site of RM placement also affect the stability. Mono-cortical fixation is generally less stable than bi-cortical.

Clinically insignificant trunnionosis in large-diameter metal-on-polyethylene total hip arthroplasty.

OBJECTIVES: Mechanical wear and corrosion at the head-stem junction of total hip arthroplasties (THAs) (trunnionosis) have been implicated in their early revision, most commonly in metal-on-metal (MOM) hips. We can isolate the role of the head-stem junction as the predominant source of metal release by investigating non-MOM hips; this can help to identify clinically significant volumes of material loss and corrosion from these surfaces. METHODS: In this study we examined a series of 94 retrieved metal-on-polyethylene (MOP) hips for evidence of corrosion and material loss at the taper junction using a well published visual grading method and an established roundness-measuring machine protocol. Hips were retrieved from 74 male and 20 female patients with a median age of 57 years (30 to 76) and a median time to revision of 215 months (2 to 324). The reasons for revision were loosening of both the acetabular component and the stem (n = 29), loosening of the acetabular component (n = 58) and infection (n = 7). No adverse tissue reactions were reported by the revision surgeons. RESULTS: Evidence of corrosion was observed in 55% of hips. The median Goldberg taper corrosion score was 2 (1 to 4) and the annual rate of material loss at the taper was 0.084 mm3/year (0 to 0.239). The median trunnion corrosion score was 1 (1 to 3). CONCLUSIONS: We have reported a level of trunnionosis for MOP hips with large-diameter heads that were revised for reasons other than trunnionosis, and therefore may be clinically insignificant.Cite this article: H. S. Hothi, D. Kendoff, C. Lausmann, J. Henckel, T. Gehrke, J. Skinner, A. Hart. Clinically insignificant trunnionosis in large-diameter metal-on-polyethylene total hip arthroplasty. Bone Joint Res 2017;6:52-56. DOI: 10.1302/2046-3758.61.BJR-2016-0150.R2.

Eversion or subluxation of patella in soft tissue balancing of total knee arthroplasty? Results of a cadaver experiment.

Correct postoperative leg alignment and stability of total knee prosthesis over the full range of movement are critical factors for successful TKA. This is achieved by correct implantation of prosthesis and soft tissue handling. However, the surgical approach and how to displace the patella are still controversial. We have carried out a cadaver study looking at the effect of patella eversion or subluxation on limb axis alignment during balancing of the knee in three different standard surgical approaches; subvastus, midvastus, or medial parapatellar. For each approach, five knees were studied. Leg alignment was visualised by the Ci CT-free DePuy/BrainLAB navigation system. Using a navigation system alignment was determined in the AP axis in both extension and 90 flexion, with the patella everted as well as subluxated. Eversion of the patella gave a more valgus axis reading than subluxation in both extension 0.58 (SD: 0.03, range 0.54 -0.60 ) and 90 flexion 0.48 (SD: 0.11, range 0.38 -0.60 ). The effect was greatest using the medial paraptellar approach. Surgeons should be aware that everting the patella influences the AP alignment when soft tissue balancing in total knee replacement.

Implementation of a new navigated parallel drill guide for femoral neck fractures.

Trauma navigation modules often use conventional mechanical surgical tools for basic simulation of drilling procedures or single screw placement. However, the precise parallel placement or specific angles that may be required are not displayed on the navigation screen. A more complex mechanical tool, a parallel drill guide (PDG) for femoral neck fractures, was integrated into a navigation module as part of this study, thus combining the advantages of mechanical tools with the benefits of fluoroscopic navigation. To implement a conventional PDG with a conventional navigation system, the tool was equipped with a non-detachable reflective marker array. Navigation engineers adapted the software to enable the navigated PDG to be displayed. We evaluated the conventional technique in comparison with the navigated technique using plastic bone models and a fresh frozen cadaver. Implementation of the navigated PDG did not pose any problems, in terms of either the software or the surgical procedure itself. The total operation time was extended by 30%, but the radiation time for the navigated group was reduced by 50%. No software or hardware-related failures occurred. Complete integration of a cannulated parallel drill guide into a navigation system has been successfully implemented. Continuous display of the mechanical guide with two parallel trajectories on the navigation screen enables safe, efficient screw placement within mechanical guidelines, without the need for additional radiographic control once initial registration has been completed.

Navigated percutaneous pelvic sacroiliac screw fixation: experimental comparison of accuracy between fluoroscopy and Iso-C3D navigation.

Percutaneous sacroiliac screw fixation is technically demanding and can result in complications mainly related to imaging problems. Furthermore, the conventional technique performed using fluoroscopic control is associated with a long radiation exposure. The purpose of this study was to evaluate the accuracy of two navigation technologies used in traumatology; fluoroscopy and Iso-C3D navigation. A total of 40 screws were placed (20 with Iso-C3D, 20 with 2D fluoroscopy) at levels S1 and S2. With both technologies, all S1 screws could be placed correctly, but four (10%) incorrect placements were seen at S2 with fluoroscopy navigation. With all Iso-C3D navigated drillings, no perforation was seen. Iso-C3D navigation therefore proved superior to 2D fluoroscopy navigation for sacroiliac screw fixation in an experimental set-up designed to assess accuracy.