Zusammenfassung Hintergrund Verletzungen der Peronealsehnen gelten als häufig unterdiagnostiziert... more Zusammenfassung Hintergrund Verletzungen der Peronealsehnen gelten als häufig unterdiagnostizierte Ursache lateraler Rückfußschmerzen. Prädisponierende Ursachen sind u. a. eine chronische laterale Instabilität sowie ein Rückfußvarus, da dies zu einer Überbelastung der Peronealsehnen führt. Klinisch äußern sich Peronealsehnenverletzungen meist unspezifisch mit lateralen Rückfußschmerzen. Material und Methoden In der Untersuchung zeigen sich Schmerzen bei Aktivierung der Sehnen gegen Widerstand. Die Sonographie zur Diagnostik bietet die Möglichkeit einer dynamischen Untersuchung, in der Magnetresonanztomographie (MRT) können gleichzeitig weitere Strukturen beurteilt werden. Zu unterscheiden sind eine Tendinopathie der Sehnen, eine Instabilität mit Luxation oder Subluxation verbunden mit Pathologien des superioren Peronealsehnenretinakulums sowie Längssplit und komplette Sehnenruptur. Bei Tendinopathien und Längsrissen erfolgt die Therapie primär konservativ. Ein kompletter Riss und ei...
Treatment of gait impairments in people with Charcot-Marie-Tooth disease is crucial, because it i... more Treatment of gait impairments in people with Charcot-Marie-Tooth disease is crucial, because it is a source of great disability. However, many clinicians find it difficult to treat these gait impairments in their daily clinical practice. This challenge is compounded by a lack of clear treat ment protocols that take the whole spectrum of treat ment options into account. As a result, there is wide variation in clinical practice. To address the widely felt need for a treatment algorithm, we present here a stepwise approach to the management of gait impairments in patients with Charcot-Marie-Tooth disease. Gait impairments in people with Charcot-Marie-Tooth disease are the combined result of ankle-foot deformities, muscle weakness, and somatosensory impairments. People with Charcot-Marie-Tooth disease often experience pain and difficulties when walking, especially barefoot. They also trip and fall frequently and have a lower than normal gait speed and distance. Because these gait impairments and related complaints are disabling, clinical management aimed at improving gait is important. Management involves both conservative and surgical treatment options, each with limited scientific evidence. However, a treatment algorithm that describes both conservative and surgical treatment options is currently lacking. This study sets out a step-wise treatment algorithm, based on evidence, if available, and otherwise reflecting practice-based experience. The treatment algorithm will be of value in daily clinical practice, and will serve as a template for future research.
Background: Lateral sliding calcaneus osteotomies are common procedures to correct hindfoot varus... more Background: Lateral sliding calcaneus osteotomies are common procedures to correct hindfoot varus deformities. Shifting the calcaneal tuberosity laterally (lateralization) can lead to tarsal tunnel pressure increase and tibial nerve palsy. The purpose of this cadaveric biomechanical study was to investigate the correlation of lateralization and pressure increase underneath the flexor retinaculum. Methods: The pressure in the tarsal tunnel of 12 Thiel-fixated human cadaveric lower legs was measured in different foot positions and varying degrees of calcaneal lateralization. Results: The mean pressure increased from plantarflexion (PF) to neutral position (NP) and from NP to hindfoot dorsiflexion (DF), and with increasing amounts of lateralization of the calcaneal tuberosity. The mean baseline pressure in PF was 1.5, in NP 2.2, and in DF 6.5 mmHg and increased to 8.1 in PF, 18.4 in NP, and 33.1 mmHg with 12 mm of lateralization. The release of the flexor retinaculum significantly lowe...
Category: Bunion Introduction/Purpose: Hallux rigidus outlines progressive degenerative changes i... more Category: Bunion Introduction/Purpose: Hallux rigidus outlines progressive degenerative changes in the 1st metatarsophalangeal joint (MTP I) by several causative factors, i.e. metatarsus primus elevatus. It often leads to disability, difficulties wearing shoes, and gait abnormalities. Despite numerous non-operative and surgical treatments for hallux rigidus reported in the literature, a gold standard treatment protocol for the disease is still missing. Thus, this study investigates the clinical and radiographic outcomes of the commonly used Reverdin-Green Osteotomy (RGO) by validated outcome measurements. Methods: We retrospectively reviewed medical records of ten patients (12 feet) that were diagnosed with hallux rigidus in the presence of metatarsus primus elevatus (MPE) and underwent RGO procedure. Primary study objective was the clinical outcomes of the RGO procedure, among others measured by validated FFI and SF12 scores. Secondary study objective was to determine any progressi...
Despite different existing methods, monitoring of free muscle transfer is still challenging. In t... more Despite different existing methods, monitoring of free muscle transfer is still challenging. In the current study we evaluated our clinical setting regarding monitoring of such tissues, using a recent microcirculation-imaging camera (EasyLDI) as an additional tool for detection of perfusion incompetency. This study was performed on seven patients with soft tissue defect, who underwent reconstruction with free gracilis muscle. Beside standard monitoring protocol (clinical assessment, temperature strips, and surface Doppler), hourly EasyLDI monitoring was performed for 48 hours. Thereby a baseline value (raised flap but connected to its vascular bundle) and an ischaemia perfusion value (completely resected flap) were measured at the same point. The mean age of the patients, mean baseline value, ischaemia value perfusion were 48.00 ± 13.42 years, 49.31 ± 17.33 arbitrary perfusion units (APU), 9.87 ± 4.22 APU, respectively. The LDI measured values in six free muscle transfers were compa...
Chi rur gie, In sel spi tal Bern, Schweiz • 2 Or tho pä di sche Chi rur gie, Spi tal zen trum Bie... more Chi rur gie, In sel spi tal Bern, Schweiz • 2 Or tho pä di sche Chi rur gie, Spi tal zen trum Biel, Schweiz • 3 Or tho pä di sche Chi rur gie, Spi tal zen trum Biel, Schweiz 4 Or tho pä di sche Chi rur gie, Spi tal zen trum Biel, Schweiz
A cavovarus foot deformity was simulated in cadaver specimens by inserting metallic wedges of 15˚... more A cavovarus foot deformity was simulated in cadaver specimens by inserting metallic wedges of 15˚ and 30˚ dorsally into the first tarsometatarsal joint. Sensors in the ankle joint recorded static tibiotalar pressure distribution at physiological load. The peak pressure increased significantly from neutral alignment to the 30˚ cavus deformity, and the centre of force migrated medially. The anterior migration of the centre of force was significant for both the 15˚ (repeated measures analysis of variance (ANOVA), p = 0.021) and the 30˚ (repeated measures ANOVA, p = 0.007) cavus deformity. Differences in ligament laxity did not influence the peak pressure. These findings support the hypothesis that the cavovarus foot deformity causes an increase in anteromedial ankle joint pressure leading to anteromedial arthrosis in the long term, even in the absence of lateral hindfoot instability.
Objectives To demonstrate the potential benefits of biochemical axial T2* mapping of intervertebr... more Objectives To demonstrate the potential benefits of biochemical axial T2* mapping of intervertebral discs (IVDs) regarding the detection and grading of early stages of degenerative disc disease using 1.5-Tesla magnetic resonance imaging (MRI) in a clinical setting. Methods Ninety-three patients suffering from lumbar spine problems were examined using standard MRI protocols including an axial T2* mapping protocol. All discs were classified morphologically and grouped as "healthy" or "abnormal". Differences between groups were analysed regarding to the specific T2* pattern at different regions of interest (ROIs). Results Healthy intervertebral discs revealed a distinct cross-sectional T2* value profile: T2* values were significantly lower in the annulus fibrosus compared with the nucleus pulposus (P00.01). In abnormal IVDs, T2* values were significantly lower, especially towards the centre of the disc representing the expected decreased water content of the nucleus (P00.01). In herniated discs, ROIs within the nucleus pulposus and ROIs covering the annulus fibrosus showed decreased T2* values. Conclusions Axial T2* mapping is effective to detect early stages of degenerative disc disease. There is a potential benefit of axial T2* mapping as a diagnostic tool, allowing the quantitative assessment of intervertebral disc degeneration. Key Points • Axial T2* mapping effective in detecting early degenerative disc disease. • Healthy and abnormal intervertebral discs revealed distinct cross-sectional T2* value profiles. • T2* can be performed at 1.5 T in a clinical setting.
Dataset. The dataset used for this article. A ZIP-archive with one text file (comma separated val... more Dataset. The dataset used for this article. A ZIP-archive with one text file (comma separated values;.csv) per participant, containing the stance-normalized navicular height and width time series from all analyzed steps. (ZIP 8335 kb)
Background Previous biomechanical studies simulating supination–external rotation (SER) IV injuri... more Background Previous biomechanical studies simulating supination–external rotation (SER) IV injuries revealed different alterations in contact area and peak pressure. We investigated joint reaction forces and radiographic parameters in an unrestrained, more physiological setup. Methods Twelve lower leg specimens were destabilized stepwise by osteotomy of the fibula (SER II) and transection of the superficial (SER IVa) and the deep deltoid ligament (SER IVb) according to the Lauge-Hansen classification. Sensors in the ankle joint recorded tibio-talar pressure changes with axial loading at 700 N in neutral position, 10° of dorsiflexion, and 20° of plantarflexion. Radiographs were taken for each step. Results Three of 12 specimen collapsed during SER IVb. In the neutral position, the peak pressure and contact area changed insignificantly from 2.6 ± 0.5 mPa (baseline) to 3.0 ± 1.4 mPa (SER IVb) ( P = .35) and from 810 ± 42 mm2 to 735 ± 27 mm2 ( P = .08), respectively. The corresponding m...
European Journal of Trauma and Emergency Surgery, 2020
The aim of this study was to investigate the influence of different ligamentous Lisfranc injuries... more The aim of this study was to investigate the influence of different ligamentous Lisfranc injuries on computed tomography (CT) findings under weight-bearing and to emphasize the indications for surgical treatment of their various types. Methods Sixteen human cadaveric lower limbs were placed in weight-bearing radiolucent frame for CT scanning. All intact specimens were initially scanned, and then, dorsal approach was used for sequential ligaments cutting of: (1) the dorsal and the interosseous (Lisfranc) ligaments between medical cuneiform (MC) and metatarsal 2 (MT2); (2) the plantar ligament between the MC and MT3; (3) the plantar ligament between MC and MT2. Based on sequential CT scans, the distances MT1-MT2, MC-T2, as well as the alignment and dorsal displacement of MT2 were measured. Results Slight increase in the distances MT1-MT2 and MC-MT2 was observed after the disruption of the dorsal and the interosseous ligaments. Further increase in MT1-MT2 and MC-MT2 distances was registered after the disruption of the ligament between MC and MT3. The largest distances MT1-MT2 and MC-MT2 were measured after the final plantar ligament cut between MC and MT2. Conclusions Unequivocal instability is observed with simultaneous transection of the Lisfranc ligament with both plantar ligaments. On CT used as diagnostic tool, plantar injuries at the basis of the second and the third metatarsal are indirect signs of violation of the ligaments and represent an indication for surgical treatment. When using magnetic resonance imaging as diagnostic tool, a ruptured Lisfranc ligament alone without dislocation does not necessarily need surgical intervention.
Category: Ankle, Ankle Arthritis Introduction/Purpose: The laterally placed trabecular metal ankl... more Category: Ankle, Ankle Arthritis Introduction/Purpose: The laterally placed trabecular metal ankle replacement is placed using a jig and a fibular osteotomy. The tibia and talus are reamed to match the curved contour of the replacement. The lateral approach was advocated to reduce the wound complications of the anterior approach. Additional fixation is achieved using two rails on the tibial and talar component. This study outlines the outcomes of 121 ankles followed prospectively with minimum 2 years follow up. Methods: 121 total ankles were consented to enrollment in a prospective study on outcomes. 10 centers were involved in the prospective study. Enrollment was from 2014 to 2016. 3 patients underwent revision and 5 withdrew (1 death, 2 lost to follow up and 2 requested discontinuation). Demographics were obtained at baseline. The average age was 59.9 at the time of surgery. 48% were male and BMI averaged 29.2. 12.4% had inflammatory arthropathy. EQ5D, AOFAS, AOS scores were obta...
Category: Ankle, Ankle Arthritis Introduction/Purpose: The laterally placed trabecular metal ankl... more Category: Ankle, Ankle Arthritis Introduction/Purpose: The laterally placed trabecular metal ankle replacement is placed using a jig and a fibular osteotomy. The tibia and talus are reamed to match the curved contour of the replacement. Additional fixation is achieved using two rails on the tibial and talar component. Additional cement fixation can be used by a bead of cement on the rail to assist in early component fixation. Cement fixation did not cover the entire ingrowth surface but was only used on the rails as per the technique manual. The purpose of this study is to compare the early results of 113 total ankle replacements with and without rail cement. Methods: 121 patients were enrolled in a prospective study. 10 centers were involved. 3 patients underwent revision and 5 withdrew (1 death, 2 lost to follow up and 2 requested discontinuation). Patients were assigned cement or no cement based on the surgeons practice. EQ5D, AOFAS, AOS scores were obtained preoperatively and at...
Journal of orthopaedic research : official publication of the Orthopaedic Research Society, Jan 19, 2018
Treatment of oblique and spiral fractures remains challenging. The aim of this study was to intro... more Treatment of oblique and spiral fractures remains challenging. The aim of this study was to introduce and investigate the new LagLoc technique for locked plating with generation of interfragmentary compression, combining the advantages of lag-screw and locking-head-screw techniques. Oblique fracture was simulated in artificial diaphyseal bones, assigned to three groups for plating with a 7-hole locking compression plate. Group I was plated with three locking screws in holes 1, 4 and 7. The central screw crossed the fracture line. In group II the central hole was occupied with a lag screw perpendicular to fracture line. Group III was instrumented applying the LagLoc technique as follows. Hole 4 was predrilled perpendicularly to the plate, followed by overdrilling of the near cortex and insertion of a locking screw whose head was covered by a holding sleeve to prevent temporarily the locking in the plate hole and generate interfragmentary compression. Subsequently, the screw head was ...
Category: Ankle, Sports, Trauma, Radiography, Weber B Fracture Introduction/Purpose: SER lateral ... more Category: Ankle, Sports, Trauma, Radiography, Weber B Fracture Introduction/Purpose: SER lateral malleolar fractures are common. The assessment of the stability of the ankle fracture is crucial for decision making of treatment which is associated with the integrity of the deltoid ligament (SERII-III). Slight talar shift can lead to extensive decrease of tibio-talar contact area (Ramsey 1999). Several clinical tests have been proposed of which static weightbearing radiography is used to measure the lateral talar shift with the medial clear space to detect medial instability (SERIV). However, the correlation of a stable ankle joint under weightbearing load with the structural integrity of the deltoid ligament has not been shown yet which we want to investigate. Methods: 17 patients with lateral malleolar fractures were investigated who underwent an MRI and weightbearing radiography examination. In the MRI, the deep deltoid ligament was assessed as intact, partial und complete rupture....
Introduction Coronal deformity is considered a relative contraindication for arthroscopic ankle f... more Introduction Coronal deformity is considered a relative contraindication for arthroscopic ankle fusion. This study assessed whether preoperative coronal ankle joint deformity influenced the outcome of arthroscopic ankle fusion. Methods 97 patients had 62 arthroscopic and 35 open ankle fusions between 2005 and 2012. Clinical outcomes were prospectively recorded with use of the Ankle Osteoarthritis Scale (AOS) and Ankle Arthritis Scale (AAS) preoperatively, 6, 12, 24 months and final follow-up. Radiological alignment was measured using the tibiotalar angle, the tibial plafond angle, the lateral talar station and the lateral tibiotalar angle. Results Both groups had the same demographics. Preoperative deformity was the same regarding sagittal alignment and overall coronal alignment but the arthroscopic group had less tibial deformity (tibial plafond angle range 0 to 19 degrees vs. 0 to 43 degrees). At final follow-up the arthroscopic mean AOS was 34.2, (95% CI 23.3 to 45.2) vs. open 33.9, (CI 17.8 to 49.9). The AAS at final follow up for arthroscopic was 26.0, (CI 21.0 to 31.0) vs. open 27.5, (CI 19.7 to 35.2). Both groups had the same tibiotalar angle, lateral talar station, and lateral tibiotalar angle at follow up.
To assess the effect of high tibial and distal femoral osteotomies (HTO and DFO) on the pressure ... more To assess the effect of high tibial and distal femoral osteotomies (HTO and DFO) on the pressure characteristics of the ankle joint.
Validity and reliability as scientific quality criteria have to be considered when using optical ... more Validity and reliability as scientific quality criteria have to be considered when using optical motion capture (OMC) for research purposes. Literature and standards recommend individual laboratory setup evaluation. However, system characteristics such as trueness, precision and uncertainty are often not addressed in scientific reports on 3D human movement analysis. One reason may be the lack of simple and practical methods for evaluating accuracy parameters of OMC. A protocol was developed for investigating the accuracy of an OMC system (Vicon®, volume 5.5×1.2×2.0 m 3) with standard laboratory equipment and by means of trueness and uncertainty of marker distances. The study investigated the effects of number of cameras (6, 8 and 10), measurement height (foot, knee and hip) and movement condition (static and dynamic) on accuracy. Number of cameras, height and movement condition affected system accuracy significantly. For lower body assessment during level walking, the most favorable setting (10 cameras, foot region) revealed mean trueness and uncertainty to be-0.08 mm and 0.33 mm, respectively. Dynamic accuracy cannot be predicted based on static error assessments. Dynamic procedures have to be used instead. The significant influence of the number of cameras and the measurement location suggests that instrumental errors should be evaluated in a laboratory-and task-specific manner. The use of standard laboratory equipment makes the proposed procedure widely applicable and it supports the setup process of OCM by simple functional error assessment. Careful system configuration and thorough measurement process control are needed to produce high-quality data.
Due to its proximal correction site and long lever arm, the Lapidus fusion, modified or not, is a... more Due to its proximal correction site and long lever arm, the Lapidus fusion, modified or not, is a powerful technique to correct hallux valgus deformities. The disadvantages are a high complication rate and a long postoperative rehabilitation period. It is only performed in 5% to 10% of all hallux valgus deformity corrections but remains, however, an important procedure, especially in moderate to severe deformities with intermetatarsal angles more than 14°, hypermobility of the first ray, arthritis of the first tarsometatarsal joint, and recurrent deformities. This article provides an overview of the procedure with special focus on the surgical technique.
Zusammenfassung Hintergrund Verletzungen der Peronealsehnen gelten als häufig unterdiagnostiziert... more Zusammenfassung Hintergrund Verletzungen der Peronealsehnen gelten als häufig unterdiagnostizierte Ursache lateraler Rückfußschmerzen. Prädisponierende Ursachen sind u. a. eine chronische laterale Instabilität sowie ein Rückfußvarus, da dies zu einer Überbelastung der Peronealsehnen führt. Klinisch äußern sich Peronealsehnenverletzungen meist unspezifisch mit lateralen Rückfußschmerzen. Material und Methoden In der Untersuchung zeigen sich Schmerzen bei Aktivierung der Sehnen gegen Widerstand. Die Sonographie zur Diagnostik bietet die Möglichkeit einer dynamischen Untersuchung, in der Magnetresonanztomographie (MRT) können gleichzeitig weitere Strukturen beurteilt werden. Zu unterscheiden sind eine Tendinopathie der Sehnen, eine Instabilität mit Luxation oder Subluxation verbunden mit Pathologien des superioren Peronealsehnenretinakulums sowie Längssplit und komplette Sehnenruptur. Bei Tendinopathien und Längsrissen erfolgt die Therapie primär konservativ. Ein kompletter Riss und ei...
Treatment of gait impairments in people with Charcot-Marie-Tooth disease is crucial, because it i... more Treatment of gait impairments in people with Charcot-Marie-Tooth disease is crucial, because it is a source of great disability. However, many clinicians find it difficult to treat these gait impairments in their daily clinical practice. This challenge is compounded by a lack of clear treat ment protocols that take the whole spectrum of treat ment options into account. As a result, there is wide variation in clinical practice. To address the widely felt need for a treatment algorithm, we present here a stepwise approach to the management of gait impairments in patients with Charcot-Marie-Tooth disease. Gait impairments in people with Charcot-Marie-Tooth disease are the combined result of ankle-foot deformities, muscle weakness, and somatosensory impairments. People with Charcot-Marie-Tooth disease often experience pain and difficulties when walking, especially barefoot. They also trip and fall frequently and have a lower than normal gait speed and distance. Because these gait impairments and related complaints are disabling, clinical management aimed at improving gait is important. Management involves both conservative and surgical treatment options, each with limited scientific evidence. However, a treatment algorithm that describes both conservative and surgical treatment options is currently lacking. This study sets out a step-wise treatment algorithm, based on evidence, if available, and otherwise reflecting practice-based experience. The treatment algorithm will be of value in daily clinical practice, and will serve as a template for future research.
Background: Lateral sliding calcaneus osteotomies are common procedures to correct hindfoot varus... more Background: Lateral sliding calcaneus osteotomies are common procedures to correct hindfoot varus deformities. Shifting the calcaneal tuberosity laterally (lateralization) can lead to tarsal tunnel pressure increase and tibial nerve palsy. The purpose of this cadaveric biomechanical study was to investigate the correlation of lateralization and pressure increase underneath the flexor retinaculum. Methods: The pressure in the tarsal tunnel of 12 Thiel-fixated human cadaveric lower legs was measured in different foot positions and varying degrees of calcaneal lateralization. Results: The mean pressure increased from plantarflexion (PF) to neutral position (NP) and from NP to hindfoot dorsiflexion (DF), and with increasing amounts of lateralization of the calcaneal tuberosity. The mean baseline pressure in PF was 1.5, in NP 2.2, and in DF 6.5 mmHg and increased to 8.1 in PF, 18.4 in NP, and 33.1 mmHg with 12 mm of lateralization. The release of the flexor retinaculum significantly lowe...
Category: Bunion Introduction/Purpose: Hallux rigidus outlines progressive degenerative changes i... more Category: Bunion Introduction/Purpose: Hallux rigidus outlines progressive degenerative changes in the 1st metatarsophalangeal joint (MTP I) by several causative factors, i.e. metatarsus primus elevatus. It often leads to disability, difficulties wearing shoes, and gait abnormalities. Despite numerous non-operative and surgical treatments for hallux rigidus reported in the literature, a gold standard treatment protocol for the disease is still missing. Thus, this study investigates the clinical and radiographic outcomes of the commonly used Reverdin-Green Osteotomy (RGO) by validated outcome measurements. Methods: We retrospectively reviewed medical records of ten patients (12 feet) that were diagnosed with hallux rigidus in the presence of metatarsus primus elevatus (MPE) and underwent RGO procedure. Primary study objective was the clinical outcomes of the RGO procedure, among others measured by validated FFI and SF12 scores. Secondary study objective was to determine any progressi...
Despite different existing methods, monitoring of free muscle transfer is still challenging. In t... more Despite different existing methods, monitoring of free muscle transfer is still challenging. In the current study we evaluated our clinical setting regarding monitoring of such tissues, using a recent microcirculation-imaging camera (EasyLDI) as an additional tool for detection of perfusion incompetency. This study was performed on seven patients with soft tissue defect, who underwent reconstruction with free gracilis muscle. Beside standard monitoring protocol (clinical assessment, temperature strips, and surface Doppler), hourly EasyLDI monitoring was performed for 48 hours. Thereby a baseline value (raised flap but connected to its vascular bundle) and an ischaemia perfusion value (completely resected flap) were measured at the same point. The mean age of the patients, mean baseline value, ischaemia value perfusion were 48.00 ± 13.42 years, 49.31 ± 17.33 arbitrary perfusion units (APU), 9.87 ± 4.22 APU, respectively. The LDI measured values in six free muscle transfers were compa...
Chi rur gie, In sel spi tal Bern, Schweiz • 2 Or tho pä di sche Chi rur gie, Spi tal zen trum Bie... more Chi rur gie, In sel spi tal Bern, Schweiz • 2 Or tho pä di sche Chi rur gie, Spi tal zen trum Biel, Schweiz • 3 Or tho pä di sche Chi rur gie, Spi tal zen trum Biel, Schweiz 4 Or tho pä di sche Chi rur gie, Spi tal zen trum Biel, Schweiz
A cavovarus foot deformity was simulated in cadaver specimens by inserting metallic wedges of 15˚... more A cavovarus foot deformity was simulated in cadaver specimens by inserting metallic wedges of 15˚ and 30˚ dorsally into the first tarsometatarsal joint. Sensors in the ankle joint recorded static tibiotalar pressure distribution at physiological load. The peak pressure increased significantly from neutral alignment to the 30˚ cavus deformity, and the centre of force migrated medially. The anterior migration of the centre of force was significant for both the 15˚ (repeated measures analysis of variance (ANOVA), p = 0.021) and the 30˚ (repeated measures ANOVA, p = 0.007) cavus deformity. Differences in ligament laxity did not influence the peak pressure. These findings support the hypothesis that the cavovarus foot deformity causes an increase in anteromedial ankle joint pressure leading to anteromedial arthrosis in the long term, even in the absence of lateral hindfoot instability.
Objectives To demonstrate the potential benefits of biochemical axial T2* mapping of intervertebr... more Objectives To demonstrate the potential benefits of biochemical axial T2* mapping of intervertebral discs (IVDs) regarding the detection and grading of early stages of degenerative disc disease using 1.5-Tesla magnetic resonance imaging (MRI) in a clinical setting. Methods Ninety-three patients suffering from lumbar spine problems were examined using standard MRI protocols including an axial T2* mapping protocol. All discs were classified morphologically and grouped as "healthy" or "abnormal". Differences between groups were analysed regarding to the specific T2* pattern at different regions of interest (ROIs). Results Healthy intervertebral discs revealed a distinct cross-sectional T2* value profile: T2* values were significantly lower in the annulus fibrosus compared with the nucleus pulposus (P00.01). In abnormal IVDs, T2* values were significantly lower, especially towards the centre of the disc representing the expected decreased water content of the nucleus (P00.01). In herniated discs, ROIs within the nucleus pulposus and ROIs covering the annulus fibrosus showed decreased T2* values. Conclusions Axial T2* mapping is effective to detect early stages of degenerative disc disease. There is a potential benefit of axial T2* mapping as a diagnostic tool, allowing the quantitative assessment of intervertebral disc degeneration. Key Points • Axial T2* mapping effective in detecting early degenerative disc disease. • Healthy and abnormal intervertebral discs revealed distinct cross-sectional T2* value profiles. • T2* can be performed at 1.5 T in a clinical setting.
Dataset. The dataset used for this article. A ZIP-archive with one text file (comma separated val... more Dataset. The dataset used for this article. A ZIP-archive with one text file (comma separated values;.csv) per participant, containing the stance-normalized navicular height and width time series from all analyzed steps. (ZIP 8335 kb)
Background Previous biomechanical studies simulating supination–external rotation (SER) IV injuri... more Background Previous biomechanical studies simulating supination–external rotation (SER) IV injuries revealed different alterations in contact area and peak pressure. We investigated joint reaction forces and radiographic parameters in an unrestrained, more physiological setup. Methods Twelve lower leg specimens were destabilized stepwise by osteotomy of the fibula (SER II) and transection of the superficial (SER IVa) and the deep deltoid ligament (SER IVb) according to the Lauge-Hansen classification. Sensors in the ankle joint recorded tibio-talar pressure changes with axial loading at 700 N in neutral position, 10° of dorsiflexion, and 20° of plantarflexion. Radiographs were taken for each step. Results Three of 12 specimen collapsed during SER IVb. In the neutral position, the peak pressure and contact area changed insignificantly from 2.6 ± 0.5 mPa (baseline) to 3.0 ± 1.4 mPa (SER IVb) ( P = .35) and from 810 ± 42 mm2 to 735 ± 27 mm2 ( P = .08), respectively. The corresponding m...
European Journal of Trauma and Emergency Surgery, 2020
The aim of this study was to investigate the influence of different ligamentous Lisfranc injuries... more The aim of this study was to investigate the influence of different ligamentous Lisfranc injuries on computed tomography (CT) findings under weight-bearing and to emphasize the indications for surgical treatment of their various types. Methods Sixteen human cadaveric lower limbs were placed in weight-bearing radiolucent frame for CT scanning. All intact specimens were initially scanned, and then, dorsal approach was used for sequential ligaments cutting of: (1) the dorsal and the interosseous (Lisfranc) ligaments between medical cuneiform (MC) and metatarsal 2 (MT2); (2) the plantar ligament between the MC and MT3; (3) the plantar ligament between MC and MT2. Based on sequential CT scans, the distances MT1-MT2, MC-T2, as well as the alignment and dorsal displacement of MT2 were measured. Results Slight increase in the distances MT1-MT2 and MC-MT2 was observed after the disruption of the dorsal and the interosseous ligaments. Further increase in MT1-MT2 and MC-MT2 distances was registered after the disruption of the ligament between MC and MT3. The largest distances MT1-MT2 and MC-MT2 were measured after the final plantar ligament cut between MC and MT2. Conclusions Unequivocal instability is observed with simultaneous transection of the Lisfranc ligament with both plantar ligaments. On CT used as diagnostic tool, plantar injuries at the basis of the second and the third metatarsal are indirect signs of violation of the ligaments and represent an indication for surgical treatment. When using magnetic resonance imaging as diagnostic tool, a ruptured Lisfranc ligament alone without dislocation does not necessarily need surgical intervention.
Category: Ankle, Ankle Arthritis Introduction/Purpose: The laterally placed trabecular metal ankl... more Category: Ankle, Ankle Arthritis Introduction/Purpose: The laterally placed trabecular metal ankle replacement is placed using a jig and a fibular osteotomy. The tibia and talus are reamed to match the curved contour of the replacement. The lateral approach was advocated to reduce the wound complications of the anterior approach. Additional fixation is achieved using two rails on the tibial and talar component. This study outlines the outcomes of 121 ankles followed prospectively with minimum 2 years follow up. Methods: 121 total ankles were consented to enrollment in a prospective study on outcomes. 10 centers were involved in the prospective study. Enrollment was from 2014 to 2016. 3 patients underwent revision and 5 withdrew (1 death, 2 lost to follow up and 2 requested discontinuation). Demographics were obtained at baseline. The average age was 59.9 at the time of surgery. 48% were male and BMI averaged 29.2. 12.4% had inflammatory arthropathy. EQ5D, AOFAS, AOS scores were obta...
Category: Ankle, Ankle Arthritis Introduction/Purpose: The laterally placed trabecular metal ankl... more Category: Ankle, Ankle Arthritis Introduction/Purpose: The laterally placed trabecular metal ankle replacement is placed using a jig and a fibular osteotomy. The tibia and talus are reamed to match the curved contour of the replacement. Additional fixation is achieved using two rails on the tibial and talar component. Additional cement fixation can be used by a bead of cement on the rail to assist in early component fixation. Cement fixation did not cover the entire ingrowth surface but was only used on the rails as per the technique manual. The purpose of this study is to compare the early results of 113 total ankle replacements with and without rail cement. Methods: 121 patients were enrolled in a prospective study. 10 centers were involved. 3 patients underwent revision and 5 withdrew (1 death, 2 lost to follow up and 2 requested discontinuation). Patients were assigned cement or no cement based on the surgeons practice. EQ5D, AOFAS, AOS scores were obtained preoperatively and at...
Journal of orthopaedic research : official publication of the Orthopaedic Research Society, Jan 19, 2018
Treatment of oblique and spiral fractures remains challenging. The aim of this study was to intro... more Treatment of oblique and spiral fractures remains challenging. The aim of this study was to introduce and investigate the new LagLoc technique for locked plating with generation of interfragmentary compression, combining the advantages of lag-screw and locking-head-screw techniques. Oblique fracture was simulated in artificial diaphyseal bones, assigned to three groups for plating with a 7-hole locking compression plate. Group I was plated with three locking screws in holes 1, 4 and 7. The central screw crossed the fracture line. In group II the central hole was occupied with a lag screw perpendicular to fracture line. Group III was instrumented applying the LagLoc technique as follows. Hole 4 was predrilled perpendicularly to the plate, followed by overdrilling of the near cortex and insertion of a locking screw whose head was covered by a holding sleeve to prevent temporarily the locking in the plate hole and generate interfragmentary compression. Subsequently, the screw head was ...
Category: Ankle, Sports, Trauma, Radiography, Weber B Fracture Introduction/Purpose: SER lateral ... more Category: Ankle, Sports, Trauma, Radiography, Weber B Fracture Introduction/Purpose: SER lateral malleolar fractures are common. The assessment of the stability of the ankle fracture is crucial for decision making of treatment which is associated with the integrity of the deltoid ligament (SERII-III). Slight talar shift can lead to extensive decrease of tibio-talar contact area (Ramsey 1999). Several clinical tests have been proposed of which static weightbearing radiography is used to measure the lateral talar shift with the medial clear space to detect medial instability (SERIV). However, the correlation of a stable ankle joint under weightbearing load with the structural integrity of the deltoid ligament has not been shown yet which we want to investigate. Methods: 17 patients with lateral malleolar fractures were investigated who underwent an MRI and weightbearing radiography examination. In the MRI, the deep deltoid ligament was assessed as intact, partial und complete rupture....
Introduction Coronal deformity is considered a relative contraindication for arthroscopic ankle f... more Introduction Coronal deformity is considered a relative contraindication for arthroscopic ankle fusion. This study assessed whether preoperative coronal ankle joint deformity influenced the outcome of arthroscopic ankle fusion. Methods 97 patients had 62 arthroscopic and 35 open ankle fusions between 2005 and 2012. Clinical outcomes were prospectively recorded with use of the Ankle Osteoarthritis Scale (AOS) and Ankle Arthritis Scale (AAS) preoperatively, 6, 12, 24 months and final follow-up. Radiological alignment was measured using the tibiotalar angle, the tibial plafond angle, the lateral talar station and the lateral tibiotalar angle. Results Both groups had the same demographics. Preoperative deformity was the same regarding sagittal alignment and overall coronal alignment but the arthroscopic group had less tibial deformity (tibial plafond angle range 0 to 19 degrees vs. 0 to 43 degrees). At final follow-up the arthroscopic mean AOS was 34.2, (95% CI 23.3 to 45.2) vs. open 33.9, (CI 17.8 to 49.9). The AAS at final follow up for arthroscopic was 26.0, (CI 21.0 to 31.0) vs. open 27.5, (CI 19.7 to 35.2). Both groups had the same tibiotalar angle, lateral talar station, and lateral tibiotalar angle at follow up.
To assess the effect of high tibial and distal femoral osteotomies (HTO and DFO) on the pressure ... more To assess the effect of high tibial and distal femoral osteotomies (HTO and DFO) on the pressure characteristics of the ankle joint.
Validity and reliability as scientific quality criteria have to be considered when using optical ... more Validity and reliability as scientific quality criteria have to be considered when using optical motion capture (OMC) for research purposes. Literature and standards recommend individual laboratory setup evaluation. However, system characteristics such as trueness, precision and uncertainty are often not addressed in scientific reports on 3D human movement analysis. One reason may be the lack of simple and practical methods for evaluating accuracy parameters of OMC. A protocol was developed for investigating the accuracy of an OMC system (Vicon®, volume 5.5×1.2×2.0 m 3) with standard laboratory equipment and by means of trueness and uncertainty of marker distances. The study investigated the effects of number of cameras (6, 8 and 10), measurement height (foot, knee and hip) and movement condition (static and dynamic) on accuracy. Number of cameras, height and movement condition affected system accuracy significantly. For lower body assessment during level walking, the most favorable setting (10 cameras, foot region) revealed mean trueness and uncertainty to be-0.08 mm and 0.33 mm, respectively. Dynamic accuracy cannot be predicted based on static error assessments. Dynamic procedures have to be used instead. The significant influence of the number of cameras and the measurement location suggests that instrumental errors should be evaluated in a laboratory-and task-specific manner. The use of standard laboratory equipment makes the proposed procedure widely applicable and it supports the setup process of OCM by simple functional error assessment. Careful system configuration and thorough measurement process control are needed to produce high-quality data.
Due to its proximal correction site and long lever arm, the Lapidus fusion, modified or not, is a... more Due to its proximal correction site and long lever arm, the Lapidus fusion, modified or not, is a powerful technique to correct hallux valgus deformities. The disadvantages are a high complication rate and a long postoperative rehabilitation period. It is only performed in 5% to 10% of all hallux valgus deformity corrections but remains, however, an important procedure, especially in moderate to severe deformities with intermetatarsal angles more than 14°, hypermobility of the first ray, arthritis of the first tarsometatarsal joint, and recurrent deformities. This article provides an overview of the procedure with special focus on the surgical technique.
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Papers by Fabian Krause