@article{HabartaJordanMeffertetal., author = {Habarta, Johanna and Jordan, Martin and Meffert, Rainer and Huflage, Henner and Schmalzl, Jonas}, title = {Surgical management of a traumatic elbow dislocation with disruption of the brachial artery. Case report}, series = {Obere Extremit{\"a}t}, volume = {17}, journal = {Obere Extremit{\"a}t}, number = {4}, issn = {1862-6599}, doi = {10.1007/s11678-022-00686-9}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-323972}, pages = {267-271}, abstract = {Background Dislocations of the elbow are the second most common dislocations of humeral joints following the shoulder. Besides numerous possible concomitant injuries of the collateral ligaments or the extensor or flexor apparatus, an accompanying disruption of the brachial artery is a rare occurrence. In the following, such a case is presented and discussed. Method A 70-year-old woman sustained a closed posterior elbow dislocation with accompanying disruption of the brachial artery due to a fall in a domestic environment. Pulselessness of the radial artery led to a computed tomography angiography being performed, which confirmed the diagnosis. Direct operative vascular reconstruction with a vein insert was carried out. Due to strong swelling of the soft tissue, other examinations of the elbow could not be performed initially. A redislocation a few days later led to an operative stabilization of the elbow joint. Results The final consultation 4 months postoperatively showed a stable, centered elbow joint and a normal perfusion of the affected arm. The elbow function was good with a range of motion of 0/0/110° of extension/flexion. Conclusion An elbow dislocation is a complex injury. An accurate clinical examination of possible concomitant injuries is important and should be repeated in the first few days after the occurrence. Vascular reconstruction should be performed immediately. In the case of persistent joint instability, an operative stabilization is indicated and may be supported by a hinged external fixator.}, language = {en} } @article{SchmalzlGrafKimmeyeretal.2022, author = {Schmalzl, Jonas and Graf, Annika and Kimmeyer, Michael and Gilbert, Fabian and Gerhardt, Christian and Lehmann, Lars-Johannes}, title = {Treatment of avascular necrosis of the humeral head - Postoperative results and a proposed modification of the classification}, series = {BMC Musculoskeletal Disorders}, volume = {23}, journal = {BMC Musculoskeletal Disorders}, doi = {10.1186/s12891-022-05338-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299815}, year = {2022}, abstract = {Background Avascular necrosis of the humeral head after proximal humeral fracture i.e. type 1 fracture sequelae (FS) according to the Boileau classification is a rare, often painful condition and treatment still remains a challenge. This study evaluates the treatment of FS type 1 with anatomic and reverse shoulder arthroplasty and a new subclassification is proposed. Methods This single-center, retrospective, comparative study, included all consecutive patients with a proximal humeral FS type 1 treated surgically in a four-year period. All patients were classified according to the proposed 3 different subtypes. Constant score (CS), Quick DASH score, subjective shoulder value (SSV) as well as revision and complication rate were analyzed. In the preoperative radiographs the acromio-humeral interval (AHI) and greater tuberosity resorption were examined. Results Of 27 with a FS type 1, 17 patients (63\%) with a mean age of 64 ± 11 years were available for follow-up at 24 ± 10 months. 7 patients were treated with anatomic and 10 with reverse shoulder arthroplasty. CS improved significantly from 16 ± 7 points to 61 ± 19 points (p < 0.0001). At final follow-up the mean Quick DASH Score was 21 ± 21 and the mean SSV was 73 ± 21 points. The mean preoperative AHI was 9 ± 3 mm, however, 8 cases presented an AHI < 7 mm. 4 cases had complete greater tuberosity resorption. The complication and revision rate was 19\%; implant survival was 88\%. Conclusion By using the adequate surgical technique good clinical short-term results with a relatively low complication rate can be achieved in FS type 1. The Boileau classification should be extended for fracture sequelae type 1 and the general recommendation for treatment with hemiarthroplasty or total shoulder arthroplasty has to be relativized. Special attention should be paid to a decreased AHI and/or resorption of the greater tuberosity as indirect signs for dysfunction of the rotator cuff. To facilitate the choice of the adequate prosthetic treatment method the suggested subclassification system should be applied.}, 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} } @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{SchmalzlGrafGilbertetal.2022, author = {Schmalzl, Jonas and Graf, Annika and Gilbert, Fabian and Kimmeyer, Michael and Gerhardt, Christian and Lehmann, Lars-Johannes}, title = {Locked fracture dislocations of the proximal humerus: postoperative results and a proposed modification of the classification}, series = {European Journal of Orthopaedic Surgery \& Traumatology}, volume = {32}, journal = {European Journal of Orthopaedic Surgery \& Traumatology}, number = {4}, issn = {1432-1068}, doi = {10.1007/s00590-021-03022-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-268454}, pages = {683-692}, year = {2022}, abstract = {Background Locked dislocations of the glenohumeral joint are disabling and often painful conditions and the treatment is challenging. This study evaluates the functional outcome and the different prosthetic treatment options for chronic locked dislocations of the glenohumeral joint and a subclassification is proposed. Methods In this single-center retrospective case series, all patients with a chronic locked dislocation treated surgically during a four-year period were analyzed. Constant score (CS), Quick Disabilities of Shoulder and Hand Score (DASH), patient satisfaction (subjective shoulder value (SSV)), revision rate and glenoid notching were analyzed. Results 26 patients presented a chronic locked dislocation of the glenohumeral joint. 16 patients (62\%) with a mean age of 75 [61-83] years were available for follow-up at 24 ± 18 months. CS improved significantly from 10 ± 6 points to 58 ± 21 points (p < 0.0001). At the final follow-up, the mean DASH was 27 ± 23 and the mean SSV was 58 ± 23 points. The complication rate was 19\% and the revision rate was 6\%; implant survival was 94\%. Scapular notching occurred in 2 (13\%) cases (all grade 1). Conclusion With good preoperative planning and by using the adequate surgical technique, good clinical short-term results with a low revision rate can be achieved. The authors suggest extending the Boileau classification for fracture sequelae type 2 and recommend using a modified classification to facilitate the choice of treatment as the suggested classification system includes locked posterior and anterior dislocations with and without glenoid bone loss.}, language = {en} } @article{SchmalzlFenwickReicheletal.2022, author = {Schmalzl, Jonas and Fenwick, Annabel and Reichel, Thomas and Schmitz, Benedikt and Jordan, Martin and Meffert, Rainer and Plumhoff, Piet and Boehm, Dirk and Gilbert, Fabian}, title = {Anterior deltoid muscle tension quantified with shear wave ultrasound elastography correlates with pain level after reverse shoulder arthroplasty}, series = {European Journal of Orthopaedic Surgery \& Traumatology}, volume = {32}, journal = {European Journal of Orthopaedic Surgery \& Traumatology}, number = {2}, issn = {1432-1068}, doi = {10.1007/s00590-021-02987-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-268441}, pages = {333-339}, year = {2022}, abstract = {Introduction Reverse shoulder arthroplasty (RSA) leads to medialization and distalization of the centre of rotation of the shoulder joint resulting in lengthening of the deltoid muscle. Shear wave ultrasound elastography (SWE) is a reliable method for quantifying tissue stiffness. The purpose of this study was to analyse if deltoid muscle tension after RSA correlates with the patients' pain level. We hypothesized that higher deltoid muscle tension would be associated with increased pain. Material and methods Eighteen patients treated with RSA were included. Constant score (CS) and pain level on the visual analogue scale (VAS) were analysed and SWE was performed on both shoulders. All three regions of the deltoid muscle were examined in resting position and under standardized isometric loading. Results Average patient age was 76 (range 64-84) years and average follow-up was 15 months (range 4-48). The average CS was 66 points (range 35-89) and the average pain level on the VAS was 1.8 (range 0.5-4.7). SWE revealed statistically significant higher muscle tension in the anterior and middle deltoid muscle region in patients after RSA compared to the contralateral non-operated side. There was a statistically significant correlation between pain level and anterior deltoid muscle tension. Conclusion SWE revealed increased tension in the anterior and middle portion of the deltoid muscle after RSA in a clinical setting. Increased tension of the anterior deltoid muscle portion significantly correlated with an increased pain level. SWE is a powerful, cost-effective, quick, dynamic, non-invasive, and radiation-free imaging technique to evaluate tissue elasticity in the shoulder with a wide range of applications.}, language = {en} } @article{SchmalzlPlumhoffGilbertetal.2019, author = {Schmalzl, Jonas and Plumhoff, Piet and Gilbert, Fabian and Gohlke, Frank and Konrads, Christian and Brunner, Ulrich and Jakob, Franz and Ebert, Regina and Steinert, Andre F.}, title = {Tendon-derived stem cells from the long head of the biceps tendon}, series = {Bone \& Joint Research}, volume = {8}, journal = {Bone \& Joint Research}, number = {9}, doi = {10.1302/2046-3758.89.BJR-2018-0214.R2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200370}, pages = {414-424}, year = {2019}, abstract = {Objectives The long head of the biceps (LHB) is often resected in shoulder surgery and could therefore serve as a cell source for tissue engineering approaches in the shoulder. However, whether it represents a suitable cell source for regenerative approaches, both in the inflamed and non-inflamed states, remains unclear. In the present study, inflamed and native human LHBs were comparatively characterized for features of regeneration. Methods In total, 22 resected LHB tendons were classified into inflamed samples (n = 11) and non-inflamed samples (n = 11). Proliferation potential and specific marker gene expression of primary LHB-derived cell cultures were analyzed. Multipotentiality, including osteogenic, adipogenic, chondrogenic, and tenogenic differentiation potential of both groups were compared under respective lineage-specific culture conditions. Results Inflammation does not seem to affect the proliferation rate of the isolated tendon-derived stem cells (TDSCs) and the tenogenic marker gene expression. Cells from both groups showed an equivalent osteogenic, adipogenic, chondrogenic and tenogenic differentiation potential in histology and real-time polymerase chain reaction (RT-PCR) analysis. Conclusion These results suggest that the LHB tendon might be a suitable cell source for regenerative approaches, both in inflamed and non-inflamed states. The LHB with and without tendinitis has been characterized as a novel source of TDSCs, which might facilitate treatment of degeneration and induction of regeneration in shoulder surgery.}, language = {en} } @article{GilbertKleinWengetal.2017, author = {Gilbert, Fabian and Klein, Detlef and Weng, Andreas Max and K{\"o}stler, Herbert and Schmitz, Benedikt and Schmalzl, Jonas and B{\"o}hm, Dirk}, title = {Supraspinatus muscle elasticity measured with real time shear wave ultrasound elastography correlates with MRI spectroscopic measured amount of fatty degeneration}, series = {BMC Muscoskeletal Disorders}, volume = {18}, journal = {BMC Muscoskeletal Disorders}, number = {549}, doi = {10.1186/s12891-017-1911-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159378}, year = {2017}, abstract = {Background: Fatty Degeneration (FD) of the rotator cuff muscles influences functional and anatomical outcome after rotator cuff repair. The MRI based estimation of fatty degeneration is the gold standard. There is some evidence that Ultrasound elastography (EUS) can detect local differences of tissue stiffness in muscles and tendons. Shear-wave elastography (SWE) was evaluated to determine the extent to which shear wave velocity was associated with measures of fatty degeneration. MRI-spectroscopic fat measurement was used as a reference to quantify the amount of fat in the muscle belly. Methods: Forty-two patients underwent SWE of the supraspinatus muscles at its thickest diameter. After ultrasound evaluation an MRI-spectroscopic fat measurement of the supraspinatus muscle was performed using the SPLASH-technique. A gel filled capsule was used to locate the measured area in the MRI. The values of shear wave velocity (SWV) measured with SWE and spectroscopic fat measurement were correlated statistically using Pearson's correlation test. Results: Correlation of the fat amount measured with MRI-spectroscopy and the SWV measured with SWE was ρ =0.82. Spectroscopic measured fat ratio of the supraspinatus muscle ranged from 0\% to 77.41\% and SWV from 1.59 m/s to 5.32 m/s. In 4 patients no sufficient SWE could be performed, these individuals showed a larger diameter of the overlying soft tissue. SWV measured with SWE showed a good correlation with MRI spectroscopic fat amount of the supraspinatus muscle. Conclusion: These preliminary data suggest that SWE may be a sufficient tool in detecting and estimating the amount of fatty degeneration in the supraspinatus muscle in real time. Large overlying soft tissue may be a limitation in performing sufficient EUS.}, language = {en} } @article{GilbertBoehmEdenetal.2016, author = {Gilbert, Fabian and B{\"o}hm, Dirk and Eden, Lars and Schmalzl, Jonas and Meffert, Rainer H. and K{\"o}stler, Herbert and Weng, Andreas M. and Ziegler, Dirk}, title = {Comparing the MRI-based Goutallier Classification to an experimental quantitative MR spectroscopic fat measurement of the supraspinatus muscle}, series = {BMC Musculoskeletal Disorders}, volume = {17}, journal = {BMC Musculoskeletal Disorders}, number = {355}, doi = {10.1186/s12891-016-1216-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147788}, year = {2016}, abstract = {Background The Goutallier Classification is a semi quantitative classification system to determine the amount of fatty degeneration in rotator cuff muscles. Although initially proposed for axial computer tomography scans it is currently applied to magnet-resonance-imaging-scans. The role for its clinical use is controversial, as the reliability of the classification has been shown to be inconsistent. The purpose of this study was to compare the semi quantitative MRI-based Goutallier Classification applied by 5 different raters to experimental MR spectroscopic quantitative fat measurement in order to determine the correlation between this classification system and the true extent of fatty degeneration shown by spectroscopy. Methods MRI-scans of 42 patients with rotator cuff tears were examined by 5 shoulder surgeons and were graduated according to the MRI-based Goutallier Classification proposed by Fuchs et al. Additionally the fat/water ratio was measured with MR spectroscopy using the experimental SPLASH technique. The semi quantitative grading according to the Goutallier Classification was statistically correlated with the quantitative measured fat/water ratio using Spearman's rank correlation. Results Statistical analysis of the data revealed only fair correlation of the Goutallier Classification system and the quantitative fat/water ratio with R = 0.35 (p < 0.05). By dichotomizing the scale the correlation was 0.72. The interobserver and intraobserver reliabilities were substantial with R = 0.62 and R = 0.74 (p < 0.01). Conclusion The correlation between the semi quantitative MRI based Goutallier Classification system and MR spectroscopic fat measurement is weak. As an adequate estimation of fatty degeneration based on standard MRI may not be possible, quantitative methods need to be considered in order to increase diagnostic safety and thus provide patients with ideal care in regard to the amount of fatty degeneration. Spectroscopic MR measurement may increase the accuracy of the Goutallier classification and thus improve the prediction of clinical results after rotator cuff repair. However, these techniques are currently only available in an experimental setting.}, language = {en} } @article{ReichertSchmalzlPrageretal.2013, author = {Reichert, Johannes and Schmalzl, Jonas and Prager, Patrick and Gilbert, Fabian and Quent, Verena M. C. and Steinert, Andre F. and Rudert, Maximilian and N{\"o}th, Ulrich}, title = {Synergistic effect of Indian hedgehog and bone morphogenetic protein-2 gene transfer to increase the osteogenic potential of human mesenchymal stem cells}, series = {Stem Cell Research \& Therapy}, journal = {Stem Cell Research \& Therapy}, doi = {10.1186/scrt316}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97010}, year = {2013}, abstract = {Introduction To stimulate healing of large bone defects research has concentrated on the application of mesenchymal stem cells (MSCs). Methods In the present study, we induced the overexpression of the growth factors bone morphogenetic protein 2 (BMP-2) and/or Indian hedgehog (IHH) in human MSCs by adenoviral transduction to increase their osteogenic potential. GFP and nontransduced MSCs served as controls. The influence of the respective genetic modification on cell metabolic activity, proliferation, alkaline phosphatase (ALP) activity, mineralization in cell culture, and osteogenic marker gene expression was investigated. Results Transduction had no negative influence on cell metabolic activity or proliferation. ALP activity showed a typical rise-and-fall pattern with a maximal activity at day 14 and 21 after osteogenic induction. Enzyme activity was significantly higher in groups cultured with osteogenic media. The overexpression of BMP-2 and especially IHH + BMP-2 resulted in a significantly higher mineralization after 28 days. This was in line with obtained quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analyses, which showed a significant increase in osteopontin and osteocalcin expression for osteogenically induced BMP-2 and IHH + BMP-2 transduced cells when compared with the other groups. Moreover, an increase in runx2 expression was observed in all osteogenic groups toward day 21. It was again more pronounced for BMP-2 and IHH + BMP-2 transduced cells cultured in osteogenic media. Conclusions In summary, viral transduction did not negatively influence cell metabolic activity and proliferation. The overexpression of BMP-2 in combination with or without IHH resulted in an increased deposition of mineralized extracellular matrix, and expression of osteogenic marker genes. Viral transduction therefore represents a promising means to increase the osteogenic potential of MSCs and the combination of different transgenes may result in synergistic effects.}, language = {en} }