@article{JordanHoelscherDohtFehskeetal.2015, author = {Jordan, Martin C. and Hoelscher-Doht, Stefanie and Fehske, Kai and Gilbert, Fabian and Jansen, Hendrik and Meffert, Rainer H.}, title = {Bunnell or cross-lock Bunnell suture for tendon repair? Defining the biomechanical role of suture pretension}, series = {Journal of Orthopaedic Surgery and Research}, volume = {10}, journal = {Journal of Orthopaedic Surgery and Research}, number = {192}, doi = {10.1186/s13018-015-0331-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126262}, year = {2015}, abstract = {Background Suture pretension during tendon repair is supposed to increase the resistance to gap formation. However, its effects on the Bunnell suture technique are unknown. The purpose of this study was to determine the biomechanical effects of suture pretension on the Bunnell and cross-lock Bunnell techniques for tendon repair. Methods Eighty porcine hindlimb tendons were randomly assigned to four different tendon repair groups: those repaired with or without suture pretension using either a simple Bunnell or cross-lock Bunnell technique. Pretension was applied as a 10 \% shortening of the sutured tendon. After measuring the cross-sectional diameter at the repair site, static and cyclic biomechanical tests were conducted to evaluate the initial and 5-mm gap formation forces, elongation during cyclic loading, maximum tensile strength, and mode of failure. The suture failure mechanism was also separately assessed fluoroscopically in two tendons that were repaired with steel wire. Results Suture pretension was accompanied by a 10 to 15 \% increase in the tendon diameter at the repair site. Therefore, suture pretension with the Bunnell and cross-lock Bunnell repair techniques noticeably increased the resistance to initial gap formation and 5-mm gap formation. The tension-free cross-lock Bunnell repair demonstrated more resistance to initial and 5-mm gap formation, less elongation, and higher maximum tensile strength than the tension-free Bunnell repair technique. The only difference between the tensioned cross-lock Bunnell and tensioned Bunnell techniques was a larger resistance to 5-mm gap formation with the cross-lock Bunnell technique. Use of the simple instead of cross-lock suture configuration led to failure by suture cut out, as demonstrated fluoroscopically. Conclusion Based on these results, suture pretension decreases gapping and elongation after tendon repair, and those effects are stronger when using a cross-lock, rather than a regular Bunnell suture. However, pretension causes an unfavorable increase in the tendon diameter at the repair site, which may adversely affect wound healing.}, language = {en} } @article{SchmidtJordanHoelscherDohtetal.2014, author = {Schmidt, Karsten and Jordan, Martin C. and H{\"o}lscher-Doht, Stefanie and Jakubietz, Michael G. and Jakubietz, Rafael G. and Meffert, Rainer H.}, title = {Suture material for flexor tendon repair: 3-0 V-Loc versus 3-0 Stratafix in a biomechanical comparison ex vivo}, doi = {10.1186/s13018-014-0072-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-110419}, year = {2014}, abstract = {Background Barbed suture material offers the possibility of knotless flexor tendon repair, as suggested in an increasing number of biomechanical studies. There are currently two different absorbable barbed suture products available, V-Loc™ and Stratafix™, and both have not been compared to each other with regard to flexor tendon repair. The purpose of this study was to evaluate both suture materials for primary stability under static and cyclic loading in a biomechanical ex vivo model. Methods Forty fresh porcine flexor digitorum profundus tendons were randomized in two groups. A four-strand modified Kessler suture technique was used to repair the tendon either with a 3-0 V-Loc™ or 3-0 Stratafix™ without a knot. Parameters of interest were mode of failure, 2-mm gap formation force, displacement, stiffness and maximum load under static and cyclic testing. Results The maximum load was 42.3 ± 7.2 for the Stratafix™ group and 50.7 ± 8.8 N for the V-Loc™ group. Thus, the ultimate tensile strength was significantly higher for V-Loc™ (p < 0.05). The 2-mm gap occurred at 24.8 ± 2.04 N in the Stratafix™ group in comparison to 26.5 ± 2.12 N in the V-Loc™ group (n.s.). Displacement was 2.65 ± 0.56 mm in the V-Loc™ group and 2.71 ± 0.59 mm in the Stratafix™ group (n.s.). Stiffness was 4.24 ± 0.68 (N/mm) in the V-Loc™ group and 3.85 ± 0.55 (N/mm) the Stratafix™ group (n.s.). Those measured differences were not significant. Conclusion V-Loc™ demonstrates a higher maximum load in tendon reconstruction. The differences in 2-mm gap formation force, displacement and stiffness were not significant. Hereby, the V-Loc™ has an advantage when used as unidirectional barbed suture for knotless flexor tendon repair.}, language = {en} } @article{HuflageFieberFaerberetal.2022, author = {Huflage, Henner and Fieber, Tabea and F{\"a}rber, Christian and Knarr, Jonas and Veldhoen, Simon and Jordan, Martin C. and Gilbert, Fabian and Bley, Thorsten Alexander and Meffert, Rainer H. and Grunz, Jan-Peter and Schmalzl, Jonas}, title = {Interobserver reliability of scapula fracture classifications in intra- and extra-articular injury patterns}, series = {BMC Musculoskeletal Disorders}, volume = {23}, journal = {BMC Musculoskeletal Disorders}, number = {1}, doi = {10.1186/s12891-022-05146-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299795}, year = {2022}, abstract = {Background Morphology and glenoid involvement determine the necessity of surgical management in scapula fractures. While being present in only a small share of patients with shoulder trauma, numerous classification systems have been in use over the years for categorization of scapula fractures. The purpose of this study was to evaluate the established AO/OTA classification in comparison to the classification system of Euler and R{\"u}edi (ER) with regard to interobserver reliability and confidence in clinical practice. Methods Based on CT imaging, 149 patients with scapula fractures were retrospectively categorized by two trauma surgeons and two radiologists using the classification systems of ER and AO/OTA. To measure the interrater reliability, Fleiss kappa (κ) was calculated independently for both fracture classifications. Rater confidence was stated subjectively on a five-point scale and compared with Wilcoxon signed rank tests. Additionally, we computed the intraclass correlation coefficient (ICC) based on absolute agreement in a two-way random effects model to assess the diagnostic confidence agreement between observers. Results In scapula fractures involving the glenoid fossa, interrater reliability was substantial (κ = 0.722; 95\% confidence interval [CI] 0.676-0.769) for the AO/OTA classification in contrast to moderate agreement (κ = 0.579; 95\% CI 0.525-0.634) for the ER classification system. Diagnostic confidence for intra-articular fracture patterns was superior using the AO/OTA classification compared to ER (p < 0.001) with higher confidence agreement (ICC: 0.882 versus 0.831). For extra-articular fractures, ER (κ = 0.817; 95\% CI 0.771-0.863) provided better interrater reliability compared to AO/OTA (κ = 0.734; 95\% CI 0.692-0.776) with higher diagnostic confidence (p < 0.001) and superior agreement between confidence ratings (ICC: 0.881 versus 0.912). Conclusions The AO/OTA classification is most suitable to categorize intra-articular scapula fractures with glenoid involvement, whereas the classification system of Euler and R{\"u}edi appears to be superior in extra-articular injury patterns with fractures involving only the scapula body, spine, acromion and coracoid process.}, language = {en} } @article{JordanJaeckleScheidtetal.2021, author = {Jordan, Martin C. and J{\"a}ckle, Veronika and Scheidt, Sebastian and Gilbert, Fabian and H{\"o}lscher-Doht, Stefanie and Erg{\"u}n, S{\"u}leyman and Meffert, Rainer H. and Heintel, Timo M.}, title = {Trans-obturator cable fixation of open book pelvic injuries}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-021-92755-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-261212}, year = {2021}, abstract = {Operative treatment of ruptured pubic symphysis by plating is often accompanied by complications. Trans-obturator cable fixation might be a more reliable technique; however, have not yet been tested for stabilization of ruptured pubic symphysis. This study compares symphyseal trans-obturator cable fixation versus plating through biomechanical testing and evaluates safety in a cadaver experiment. APC type II injuries were generated in synthetic pelvic models and subsequently separated into three different groups. The anterior pelvic ring was fixed using a four-hole steel plate in Group A, a stainless steel cable in Group B, and a titan band in Group C. Biomechanical testing was conducted by a single-leg-stance model using a material testing machine under physiological load levels. A cadaver study was carried out to analyze the trans-obturator surgical approach. Peak-to-peak displacement, total displacement, plastic deformation and stiffness revealed a tendency for higher stability for trans-obturator cable/band fixation but no statistical difference to plating was detected. The cadaver study revealed a safe zone for cable passage with sufficient distance to the obturator canal. Trans-obturator cable fixation has the potential to become an alternative for symphyseal fixation with less complications.}, language = {en} } @article{JordanJansenMeffertetal.2021, author = {Jordan, Martin C. and Jansen, Hendrik and Meffert, Rainer H. and Heintel, Timo M.}, title = {Comparing porous tantalum fusion implants and iliac crest bone grafts for spondylodesis of thoracolumbar burst fractures: Prospectice Cohort study}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-021-96400-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-261706}, year = {2021}, abstract = {The aim of this study was to compare two different techniques of performing one-level spondylodesis for thoracolumbar burst fractures using either an autologous iliac crest bone graft (ICBG) or a porous tantalum fusion implant (PTFI). In a prospective nonrandomized study, 44 patients (20 women, 24 men; average age 43.1 +/- 13.2 years) suffering from severe thoracolumbar burst fractures were treated with combined anterior-posterior stabilization. An ICBG was used in 21 cases, and a PTFI was used in the other 23 cases. A two-year clinical and radiographic follow-up was carried out. There were no statistically significant differences in age, sex, localization/classification of the fracture, or visual analog scale (VAS) before injury between the two groups. All 44 patients were followed up for an average period of 533 days (range 173-1567). The sagittal spinal profile was restored by an average of 11.1 degrees (ICBG) vs. 14.3 degrees (PTFI) (monosegmental Cobb angle). Loss of correction until the last follow-up tended to be higher in the patients treated with ICBG than in those treated with PTFI (mean: 2.8 degrees vs. 1.6 degrees). Furthermore, significantly better restoration of the sagittal profile was obtained with the PTFI than with the iliac bone graft at the long-term follow-up (mean: ICBG 7.8 degrees, PTFI 12.3 degrees; p < 0.005). Short-segment posterior instrumentation combined with anterior one-level spondylodesis using either an ICBG or a PTFI resulted in sufficient correction of posttraumatic segmental kyphosis. PTFI might be a good alternative for autologous bone grafting and prevent donor site morbidities.}, language = {en} } @article{JordanBroeerFischeretal.2022, author = {Jordan, Martin C. and Br{\"o}er, David and Fischer, Christian and Heilig, Philipp and Gilbert, Fabian and H{\"o}lscher-Doht, Stefanie and Kalogirou, Charis and Popp, Kevin and Grunz, Jan-Peter and Huflage, Henner and Jakubietz, Rafael G. and Erg{\"u}n, S{\"u}leyman and Meffert, Rainer H.}, title = {Development and preclinical evaluation of a cable-clamp fixation device for a disrupted pubic symphysis}, series = {Communications Medicine}, volume = {2}, journal = {Communications Medicine}, number = {1}, doi = {10.1038/s43856-022-00227-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299800}, year = {2022}, abstract = {Background Traumatic separation of the pubic symphysis can destabilize the pelvis and require surgical fixation to reduce symphyseal gapping. The traditional approach involves open reduction and the implantation of a steel symphyseal plate (SP) on the pubic bone to hold the reposition. Despite its widespread use, SP-fixation is often associated with implant failure caused by screw loosening or breakage. Methods To address the need for a more reliable surgical intervention, we developed and tested two titanium cable-clamp implants. The cable served as tensioning device while the clamp secured the cable to the bone. The first implant design included a steel cable anterior to the pubic symphysis to simplify its placement outside the pelvis, and the second design included a cable encircling the pubic symphysis to stabilize the anterior pelvic ring. Using highly reproducible synthetic bone models and a limited number of cadaver specimens, we performed a comprehensive biomechanical study of implant stability and evaluated surgical feasibility. Results We were able to demonstrate that the cable-clamp implants provide stability equivalent to that of a traditional SP-fixation but without the same risks of implant failure. We also provide detailed ex vivo evaluations of the safety and feasibility of a trans-obturator surgical approach required for those kind of fixation. Conclusion We propose that the developed cable-clamp fixation devices may be of clinical value in treating pubic symphysis separation.}, language = {en} } @article{JordanZimmermannGhoetal.2016, author = {Jordan, Martin C. and Zimmermann, Christina and Gho, Sheridan A. and Frey, S{\"o}nke P. and Blunk, Torsten and Meffert, Rainer H. and Hoelscher-Doht, Stefanie}, title = {Biomechanical analysis of different osteosyntheses and the combination with bone substitute in tibial head depression fractures}, series = {BMC Musculoskeletal Disorders}, volume = {17}, journal = {BMC Musculoskeletal Disorders}, number = {287}, doi = {10.1186/s12891-016-1118-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-161201}, year = {2016}, abstract = {Background Tibial head depression fractures demand a high level of fracture stabilization to prevent a secondary loss of reduction after surgery. Elderly individuals are at an increased risk of developing these fractures, and biomechanical investigations of the fractures are rare. Therefore, the aim of this study was to systematically analyze different types of osteosyntheses in combination with two commonly used bone substitutes. Methods Lateral tibial head depression fractures were created in synthetic bones. After reduction, the fractures were stabilized with eight different treatment options of osteosynthesis alone or in combination with a bone substitute. Two screws, 4 screws and a lateral buttress plate were investigated. As a bone substitute, two common clinically used calcium phosphate cements, Norian® Drillable and ChronOS™ Inject, were applied. Displacement of the articular fracture fragment (mm) during cyclic loading, stiffness (N/mm) and maximum load (N) in Load-to-Failure tests were measured. Results The three different osteosyntheses (Group 1: 2 screws, group 2: 4 screws, group 3: plate) alone revealed a significantly higher displacement compared to the control group (Group 7: ChronOS™ Inject only) (Group 1, 7 [p < 0.01]; group 2, 7 [p = 0.04]; group 3, 7 [p < 0.01]). However, the osteosyntheses in combination with bone substitute exhibited no differences in displacement compared to the control group. The buttress plate demonstrated a higher normalized maximum load than the 2 and 4 screw osteosynthesis. Comparing the two different bone substitutes to each other, ChronOS™ inject had a significantly higher stiffness and lower displacement than Norian® Drillable. Conclusions The highest biomechanical stability under maximal loading was provided by a buttress plate osteosynthesis. A bone substitute, such as the biomechanically favorable ChronOS™ Inject, is essential to reduce the displacement under lower loading.}, language = {en} } @article{JordanJovicGilbertetal.2020, author = {Jordan, Martin C. and Jovic, Sebastian and Gilbert, Fabian and Kunz, Andreas and Ertl, Maximilian and Strobl, Ute and Jakubietz, Rafael G. and Jakubietz, Michael G. and Meffert, Rainer H. and Fuchs, Konrad F.}, title = {Qualit{\"a}tssteigerung der Abrechnungspr{\"u}fung durch Smartphone-basierte Fotodokumentation in der Unfall-, Hand-, und Plastischen Chirurgie}, series = {Der Unfallchirurg}, volume = {124}, journal = {Der Unfallchirurg}, issn = {0177-5537}, doi = {10.1007/s00113-020-00866-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-232415}, pages = {366-372}, year = {2020}, abstract = {Hintergrund Die Fotodokumentation von offenen Frakturen, Wunden, Dekubitalulzera, Tumoren oder Infektionen ist ein wichtiger Bestandteil der digitalen Patientenakte. Bisher ist unklar, welchen Stellenwert diese Fotodokumentation bei der Abrechnungspr{\"u}fung durch den Medizinischen Dienst der Krankenkassen (MDK) hat. Fragestellung Kann eine Smartphone-basierte Fotodokumentation die Verteidigung von erl{\"o}srelevanten Diagnosen und Prozeduren sowie der Verweildauer verbessern? Material und Methoden Ausstattung der Mitarbeiter mit digitalen Endger{\"a}ten (Smartphone/Tablet) in den Bereichen Notaufnahme, Schockraum, OP, Sprechstunden sowie auf den Stationen. Retrospektive Auswertung der Abrechnungspr{\"u}fung im Jahr 2019 und Identifikation aller Fallbesprechungen, in denen die Fotodokumentation eine Erl{\"o}sver{\"a}nderung bewirkt hat. Ergebnisse Von insgesamt 372 Fallbesprechungen half die Fotodokumentation in 27 F{\"a}llen (7,2 \%) zur Best{\"a}tigung eines Operationen- und Prozedurenschl{\"u}ssels (OPS) (n = 5; 1,3 \%), einer Hauptdiagnose (n = 10; 2,7 \%), einer Nebendiagnose (n = 3; 0,8 \%) oder der Krankenhausverweildauer (n = 9; 2,4 \%). Pro oben genanntem Fall mit Fotodokumentation ergab sich eine durchschnittliche Erl{\"o}ssteigerung von 2119 €. Inklusive Aufwandpauschale f{\"u}r die Verhandlungen wurde somit ein Gesamtbetrag von 65.328 € verteidigt. Diskussion Der Einsatz einer Smartphone-basierten Fotodokumentation kann die Qualit{\"a}t der Dokumentation verbessern und Erl{\"o}seinbußen bei der Abrechnungspr{\"u}fung verhindern. Die Implementierung digitaler Endger{\"a}te mit entsprechender Software ist ein wichtiger Teil des digitalen Strukturwandels in Kliniken.}, language = {de} } @article{HeiligFaerberPauletal.2022, author = {Heilig, Philipp and Faerber, Lars-Christopher and Paul, Mila M. and Kupczyk, Eva and Meffert, Rainer H. and Jordan, Martin C. and Hoelscher-Doht, Stefanie}, title = {Plate osteosynthesis combined with bone cement provides the highest stability for tibial head depression fractures under high loading conditions}, series = {Scientific Reports}, volume = {12}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-022-19107-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299782}, year = {2022}, abstract = {Older patients sustaining tibial head depression fractures often cannot follow the post-operative rehabilitation protocols with partial weight-bearing of the affected limb, leading to osteosynthesis failure, cartilage step-off and arthritis development. Therefore, the aim of this study was to analyse the biomechanical performance of different types of osteosyntheses alone and in combination with bone cement simulating cyclically high loading conditions of tibial head depression fractures. Lateral tibial head depression fractures (AO: 41-B2.2; Schatzker type III) were created in synthetic bones and stabilized using three different osteosyntheses alone and in combination with a commonly used bone cement (chronOS™): 2 screws, 4 screws in the jail technique and a lateral angle-stable buttress plate. After fixation, the lateral tibial plateau was axially loaded in two, from each other independent testing series: In the first test protocol, 5000 cycles with 500 N and in the end load-to-failure tests were performed. In the second test protocol, the cyclic loading was increased to 1000 N. Parameters of interest were the displacement of the articular fracture fragment, the stiffness and the maximum load. The osteosyntheses revealed a higher stiffness in combination with bone cement compared to the same type of osteosynthesis alone (e.g., 500 N level: 2 screws 383 ± 43 N/mm vs. 2 screws + chronOs 520 ± 108 N/mm, increase by 36\%, p < 0.01; 4 screws 368 ± 97 N/mm vs. 4 screws + chronOS 516 ± 109 N/mm, increase by 40\%, p < 0.01; plate: 509 ± 73 N/mm vs. plate + chronOs 792 ± 150 N/mm, increase by 56\%, p < 0.01). Bone cement reduced the displacement of the plate significantly (500 N level: plate: 8.9 ± 2.8 mm vs. plate + chronOs: 3.1 ± 1.4 mm, reduction by 65\%, p < 0.01; 1000 N level: 16.9 ± 3.6 mm vs 5.6 ± 1.3 mm, reduction by 67\%, p < 0.01). Thus, the highest stiffness and lowest displacement values were found when using the plate with bone cement in both loading conditions (500 N level: 2 screws + chronOs 3.7 ± 1.3 mm, 4 screws + chronOs 6.2 ± 2.4 mm; 1000 N level: 2 screws + chronOs 6.5 ± 1.2 mm, 4 screws + chronOs 5.7 ± 0.8 mm). From a biomechanical perspective, plate osteosynthesis of tibial head depression fractures should always be combined with bone cement, provides higher stability than 2-screw and 4-screw fixation and is a valid treatment option in cases where extraordinary stability is required.}, language = {en} } @article{JordanHufnagelMcDonoghetal.2022, author = {Jordan, Martin C. and Hufnagel, Lukas and McDonogh, Miriam and Paul, Mila M. and Schmalzl, Jonas and Kupczyk, Eva and Jansen, Hendrik and Heilig, Philipp and Meffert, Rainer H. and Hoelscher-Doht, Stefanie}, title = {Surgical fixation of calcaneal beak fractures — biomechanical analysis of different osteosynthesis techniques}, series = {Frontiers in Bioengineering and Biotechnology}, volume = {10}, journal = {Frontiers in Bioengineering and Biotechnology}, issn = {2296-4185}, doi = {10.3389/fbioe.2022.896790}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-282792}, year = {2022}, abstract = {The calcaneal beak fracture is a rare avulsion fracture of the tuber calcanei characterized by a solid bony fragment at the Achilles tendon insertion. Treatment usually requires osteosynthesis. However, lack of biomechanical understanding of the ideal fixation technique persists. A beak fracture was simulated in synthetic bones and assigned to five different groups of fixation: A) 6.5-mm partial threaded cannulated screws, B) 4.0-mm partial threaded cannulated screws, C) 5.0-mm headless cannulated compression screws, D) 2.3-mm locking plate, and E) 2.8-mm locking plate. Different traction force levels were applied through an Achilles tendon surrogate in a material-testing machine on all stabilized synthetic bones. Outcome measures were peak-to-peak displacement, total displacement, plastic deformation, stiffness, visual-fracture-line displacement, and mode of implant failure. The 2.3- and 2.8-mm plating groups showed a high drop-out rate at 100 N tension force and failed under higher tension levels of 200 N. The fracture fixation using 4.0-mm partial threaded screws showed a significantly higher repair strength and was able to withhold cyclic loading up to 300 N. The lowest peak-to-peak displacement and the highest load-to-failure and stiffness were provided by fracture fixation using 6.5-mm partial threaded cannulated screws or 5.0-mm headless cannulated compression screws. As anticipated, large 6.5-mm screw diameters provide the best biomechanical fixation. Surprisingly, the 5.0-mm headless cannulated compression screws yield reliable stability despite the absent screw head and washer. When such large screws cannot be applied, 4.0-mm screws also allow reasonable fixation strength. Plate fixation should be implemented with precaution and in combination with a restrictive postoperative motion protocol. Finally, clinical cases about the surgical application and recovery are included.}, language = {en} }