TY - JOUR A1 - Reichert, Johannes C. A1 - von Rottkay, Eberhard A1 - Roth, Franz A1 - Renz, Tim A1 - Hausmann, Johannes A1 - Kranz, Julius A1 - Rackwitz, Lars A1 - Nöth, Ulrich A1 - Rudert, Maximilian T1 - A prospective randomized comparison of the minimally invasive direct anterior and the transgluteal approach for primary total hip arthroplasty JF - BMC Musculoskeletal Disorders N2 - Background: The presented prospective randomized controlled single-centre study compares the clinical outcome up to 12 months after total hip arthroplasty using a minimally invasive single-incision direct anterior (DAA) and a direct transgluteal lateral approach. Methods: A total of 123 arthroplasties were evaluated utilizing the Harris Hip Score (HHS), the extra short musculoskeletal functional assessment questionnaire (XSFMA), the Short Form 36 (SF-36) health survey, a Stepwatch™ Activity Monitor (SAM), and a timed 25 m foot walk (T25-FW). Postoperative x-ray images after THA were reviewed to determine inclination and stem positioning. Results: At final follow-up, the XSFMA functional index scores were 10.3 (anterior) and 15.08 (lateral) while the bother index summed up to a score of 15.8 (anterior) and 21.66 (lateral) respectively, thus only differing significantly for the functional index (p = 0.040 and p = 0.056). The SF-36 physical component score (PCS) was 47.49 (anterior) and 42.91 (lateral) while the mental component score (MCS) summed up to 55.0 (anterior) and 56.23 (lateral) with a significant difference evident for the PCS (p = 0.017; p = 0.714). Patients undergoing THA through a DAA undertook a mean of 6402 cycles per day while those who had undergone THA through a transgluteal approach undertook a mean of 5340 cycles per day (p = 0.012). Furthermore, the obtained outcome for the T25-FW with 18.4 s (anterior) and 19.75 s (lateral) and the maximum walking distance (5932 m and 5125 m) differed significantly (p = 0.046 and p = 0.045). The average HHS showed no significant difference equaling 92.4 points in the anterior group and 91.43 in the lateral group (p = 0.477). The radiographic analysis revealed an average cup inclination of 38.6° (anterior) and 40.28° (lateral) without signs of migration. Conclusion: In summary, our outcomes show that after 1 year THA through the direct anterior approach results in a higher patient activity compared to THA utilizing a transgluteal lateral approach while no differences regarding hip function are evident. KW - total hip arthroplasty KW - direct anterior approach KW - minimally invasive KW - transgluteal approach KW - prospective study Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176072 VL - 19 IS - 241 ER - TY - JOUR A1 - Boelch, Sebastian Philipp A1 - Weissenberger, Manuel A1 - Spohn, Frederik A1 - Rudert, Maximilian A1 - Luedemann, Martin T1 - Insufficient sensitivity of joint aspiration during the two-stage exchange of the hip with spacers JF - Journal of Orthopedic Surgery and Research N2 - Background: Evaluation of infection persistence during the two-stage exchange of the hip is challenging. Joint aspiration before reconstruction is supposed to rule out infection persistence. Sensitivity and specificity of synovial fluid culture and synovial leucocyte count for detecting infection persistence during the two-stage exchange of the hip were evaluated. Methods: Ninety-two aspirations before planned joint reconstruction during the two-stage exchange with spacers of the hip were retrospectively analyzed. Results: The sensitivity and specificity of synovial fluid culture was 4.6 and 94.3%. The sensitivity and specificity of synovial leucocyte count at a cut-off value of 2000 cells/μl was 25.0 and 96.9%. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) values were significantly higher before prosthesis removal and reconstruction or spacer exchange (p = 0.00; p = 0.013 and p = 0.039; p = 0.002) in the infection persistence group. Receiver operating characteristic area under the curve values before prosthesis removal and reconstruction or spacer exchange for ESR were lower (0.516 and 0.635) than for CRP (0.720 and 0.671). Conclusions: Synovial fluid culture and leucocyte count cannot rule out infection persistence during the two-stage exchange of the hip. KW - two-stage exchange KW - hip KW - periprosthetic infection KW - joint aspiration KW - spacer Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175576 VL - 13 IS - 7 ER - TY - JOUR A1 - Boelch, Sebastian P. A1 - Rueckl, Kilian A1 - Fuchs, Clara A1 - Jordan, Martin A1 - Knauer, Markus A1 - Steinert, Andre A1 - Rudert, Maximilian A1 - Luedemann, Martin T1 - Comparison of elution characteristics and compressive strength of biantibiotic-loaded PMMA bone cement for spacers: Copal\(^®\) spacem with gentamicin and vancomycin versus Palacos\(^®\) R+G with vancomycin JF - BioMed Research International N2 - Purpose. Copal\(^®\) spacem is a new PMMA bone cement for fabricating spacers. This study compares elution of gentamicin, elution of vancomycin, and compressive strength of Copal\(^®\) spacem and of Palacos\(^®\) R+G at different vancomycin loadings in the powder of the cements. We hypothesized that antibiotic elution of Copal\(^®\) spacem is superior at comparable compressive strength. Methods. Compression test specimens were fabricated using Copal\(^®\) spacem manually loaded with 0.5 g gentamicin and additionally 2 g, 4 g, and 6 g of vancomycin per 40 g of cement powder (COP specimens) and using 0.5 g gentamicin premixed Palacos\(^®\) R+G manually loaded with 2 g, 4 g, and 6 g of vancomycin per 40 g of cement powder (PAL specimens). These specimens were used for determination of gentamicin and vancomycin elution (in fetal calf serum, at 22°C) and for determination of compressive strength both prior and following the elution tests. Results. Cumulative gentamicin concentrations (p < 0.005) and gentamicin concentration after 28 days (p ≤ 0.043) were significantly lower for COP specimens compared to PAL specimens. Cumulative vancomycin concentrations were significantly higher (p ≤ 0.043) for COP specimens after the second day. Vancomycin concentrations after 28 days were not significantly higher for the Copal specimens loaded with 2 g and 4 g of vancomycin. Compressive strength was not significantly different between COP specimens and PAL specimens before elution tests. Compressive strength after the elution tests was significantly lower (p = 0.005) for COP specimens loaded with 2 g of vancomycin. Conclusion. We could not demonstrate consistent superior antibiotic elution from Copal\(^®\) spacem compared to Palacos\(^®\) R+G for fabricating gentamicin and vancomycin loaded spacers. The results do not favor Copal\(^®\) spacem over Palacos\(^®\) R+G for the use as a gentamicin and vancomycin biantibiotic-loaded spacer. KW - Copal\(^®\) spacem KW - PMMA bone cement KW - elution KW - compressive strength Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-177435 VL - 2018 IS - 4323518 ER - TY - JOUR A1 - Boelch, Sebastian P. A1 - Roth, Magnus A1 - Arnholdt, Joerg A1 - Rudert, Maximilian A1 - Luedemann, Martin T1 - Synovial fluid aspiration should not be routinely performed during the two-stage exchange of the knee JF - BioMed Research International N2 - Purpose. Detection of infection persistence during the two-stage exchange of the knee for periprosthetic joint infection is challenging. Synovial fluid culture (SFC) and synovial white blood cell count (SWBCC) before joint reimplantation are widespread diagnostic means for this indication. The sensitivity and specificity of SFC and of SWBCC for infection persistence before planned reimplantation were evaluated. Methods. 94 two-stage exchanges of the knee with synovial fluid aspiration performed after a drug holiday of at least 14 days and before reimplantation or spacer exchange (planned reimplantation) were retrospectively analyzed. Only cases with at least 3 intraoperative samples at planned reimplantation were included. SFC and SWBCC were compared to pathogen detection (SFC\(_{(culture)}\)/SWBCC\(_{(culture)}\) and to histopathological signs of infection persistence (SFC\(_{(histo)}\)/SWBCC\(_{(histo)}\) from intraoperative samples at planned reimplantation. For SFC, the sensitivity and specificity were calculated. For SWBCC, the optimal cut-off value with its sensitivity and specificity was calculated with the Youden-Index. Results. Sensitivity and specificity of SFC\(_{(culture)}\) were 0.0% and 98.9%. Sensitivity and specificity of SFC\(_{(histo)}\) were 3.4% and 100%. The optimal cut-off value for SWBCC\(_{(culture)}\) was 4450 cells/μl with a sensitivity of 50.0% and a specificity of 86.5%. The optimal cut-off value for SWBCC\(_{(histo)}\) was 3250 cells/μl with a sensitivity of 35.7% and a specificity of 92.9%. Conclusion. The detection of infection persistence remains challenging and a consented approach is lacking. The results do not warrant the routine performance of SFC during the two-stage exchange at the knee. SWBCC can be used to confirm infection persistence at high cut-offs, but they only occur in few patients and are therefore inappropriate for the routine use. KW - knee KW - two-stage exchange KW - Synovial Fluid Aspiration Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176800 VL - 2018 IS - 6720712 ER - TY - JOUR A1 - Arnholdt, Jörg A1 - Kamawal, Yama A1 - Holzapfel, Boris Michael A1 - Ripp, Axel A1 - Rudert, Maximilian A1 - Steinert, Andre Friedrich T1 - Evaluation of implant fit and frontal plane alignment after bi-compartmental knee arthroplasty using patient-specific instruments and implants JF - Archives of Medical Science N2 - Introduction The goals of successful bi-compartmental knee arthroplasty are to achieve correct fit and positioning of the implant, while appropriately correcting the mechanical alignment of the leg after surgery. As these requirements are not always reliably fulfilled using off-the-shelf implant systems, newer approaches for bi-compartmental resurfacing have been explored. Material and methods In this article we report the radiographic results of 30 patients with anteromedial osteoarthritis (OA) who were treated with a novel patient-specific fixed-bearing bi-compartmental knee resurfacing system using custom-made implants and instruments. Utilizing standardized pre- and postoperative radiographic analyses (based on anterior-posterior and lateral, anterior-posterior weight-bearing full-length radiographs, patella skyline views and preoperative computed tomography (CT) scanning) implant fit and positioning as well as correction of the mechanical axis (hip-knee-ankle angle, HKA) were determined. Results On average, HKA was corrected from 173.4 ±3.47° preoperatively to 179.4 ±2.85° postoperatively. The coronal femoro-tibial angle was corrected on average 5.61°. The preoperative tibial slope measured on lateral views was 6.38 ±2.4°, while the average slope in the CT-based planning protocol (iView) was 6.14 ±2.40°. Postoperative lateral tibial slope was determined to be 5.77 ±1.97°. The thickness of the posterior femoral cuts was measured intraoperatively and, in all cases, corresponded well to the targeted thickness of the cuts provided by the iView. The joint line was preserved in all cases and the average Insall-Salvati index was 1.078 ±0.11 pre- and 1.072 ±0.11 postoperatively. The fit of the implant components measured by over- or underhang was excellent throughout (< 1.01 mm). Conclusions Custom-made bicompartmental knee arthroplasty can ensure optimized fitting and positioning of the implant with restoration of the leg axis. These implants could be considered as an alternative primary solution for knee surgeons treating bi-compartmental disease. KW - implant fit KW - bi-compartmental knee arthoplasty KW - bi-compartmental KW - implant positioning KW - knee osteoarthritis KW - knee arthroplasty KW - patient-specific KW - knee alignment Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-159668 VL - 14 IS - 6 ER -