Microcephaly, short stature, and limb abnormality disorder due to novel autosomal biallelic DONSON mutations in two German siblings.

Recently, variants in DONSON have been reported to cause different disorders of the microcephalic primordial dwarfism spectrum. Using whole-exome sequencing, we identified two novel, compound heterozygous DONSON variants in a pair of siblings, one of whom was previously diagnosed with Fanconi anemia. This occurred because the present cases exhibited clinical findings in addition to those of the microcephalic primordial dwarfism disorder, including severe limb malformations. These findings suggest that the DONSON and Fanconi anemia proteins could have supplementary roles in developmental processes as they have in the maintenance of genomic integrity, resulting in related disease phenotypes.

Systematic classification of uterine cervical elongation in patients with pelvic organ prolapse.

OBJECTIVE: To define and classify cervical elongation, to compare uterine measurements after prolapse hysterectomy with a non-prolapse control group, and to associate stage of prolapse and degree of cervical elongation. STUDY DESIGN: This was a single-centre retrospective case-control study conducted at the University Hospital, Urogynaecological Unit, with a certified urogynaecological surgeon. Data were collected from patients with and without pelvic organ prolapse (POP) who underwent laparoscopically assisted vaginal hysterectomy. Post-hysterectomy uterine cervical elongation was examined using the corpus/cervix ratio (CCR), calculated from measurements taken on photographs. Cervical elongation was classified as physiological (grade 0, CCR>1.5) grade I (CCR>1 and ≤1.5) grade II (CCR>0.5 and ≤1), and grade III (CCR≤0.5). RESULTS: Cervical elongation was detected in 288/295 (97.6%) patients in the prolapse group (grade I, 44/288 [15.2%]; grade II, 212 [73.6%]; grade III, 32 [11.1%]). Mean CCR was greater among those with stage II/III than among those with stage IV prolapse (1.0±0.4 vs. 0.8±0.2; p<0.001). Grades of cervical elongation and prolapse stages were associated (p<0.001). Grade I cervical elongation was detected in 26/69 (37.6%), grade II in 5/69, and grade III in 0/69 patients of the control group. Cervical elongation was found more often in the prolapse group compared to the control group (p<0.001). Mean total uterine length did not differ between the prolapse and control groups (8.0±1.6 vs. 8.2±1.3cm), but mean calculated cervical length was greater in the prolapse group than in the control group (4.4±1.1 vs. 3.1+0.8cm; p<0.001). CONCLUSIONS: Uterine cervical elongation is found in patients undergoing hysterectomy for pelvic organ prolapse. Cervical elongation grades and prolapse stages are correlated. Defining uterine cervical elongation based on corpus/cervix ratio with grades I-III could be a valuable basic tool for further research.

Lateral soft-tissue release through a medial incision: Anatomic comparison of two techniques.

BACKGROUND: The distal soft tissue procedure is an integral part of hallux valgus surgery, providing soft tissue balance and alignment restoration of the first metatarsophalangeal joint. Various approaches have been established to this end. For techniques that do not include a separate dorsal incision, lateral release may be achieved via a transarticular approach or via a medial incision and a dorsal flap over the first metatarsal. Compared to the double-incision technique, these techniques are not only cosmetically superior and thus meet the demands of most surgeons and patients. MATERIAL AND METHODS: Using six pairs of frozen cadaveric feet, lateral release was performed using one of the above techniques in a randomized manner with pair comparison. The specimens were then dissected and the completeness of the release as well as any damage to anatomic structures was documented. RESULTS: The transarticular technique enabled complete release of the metatarsal-sesamoid suspensory ligament (MSL) and the transverse and oblique head of the adductor hallucis muscle in five of six specimens. The comparative technique enabled the same in only two of six cases for the adductor hallucis muscle and in four cases for the MSL. The transarticular approach achieved complete release of the lateral joint capsule in three of six specimens, whereas the dorsal approach achieved no release in any specimen. Neither of the methods caused any macroscopic injury to the surfaces of the first metatarsophalangeal joint. The examined arteries, veins, and nerves remained intact in all specimens treated with the transarticular approach, but dorsal release resulted in one documented injury to the first dorsal metatarsal artery and its concomitant veins. CONCLUSIONS: Compared to release by dissection superficially to the extensor tendons, transarticular release provides a more complete lateral release and less injuries to neurovascular bundles. Further anatomic and clinical studies are needed, however, before conclusive recommendations can be made.

First Tarsometatarsal Arthrodesis: An Anatomic Evaluation of Dorsomedial Versus Plantar Plating.

Fusion of the first tarsometatarsal joint is a widely used procedure for the correction of hallux valgus deformity. Although dorsomedial H-shaped plating systems are being increasingly used, fusion can also be achieved by plantar plating. The goal of the present study was to compare these 2 operative techniques based on the anatomic considerations and show the potential pitfalls of both procedures. Six pairs of deep-frozen human lower legs were used in the present cadaveric study. In a randomized manner, either dorsomedial arthrodesis or plantar plating through a medial incision was performed. With regard to arterial injury, the plantar technique resulted in fewer lesions (plantar, 4 injuries [66.7%] to the terminal branches of the first digital branch of the medial plantar artery; dorsomedial, 3 injuries [50%] to the main trunks of the plantar metatarsal arteries and the first dorsal metatarsal artery). With respect to injury to the veins, the plantar procedure affected significantly fewer high-caliber subcutaneous trunk veins. The nerves coursing through the operative field, such as the saphenous and superficial fibular nerves, were compromised more often by the dorsal approach. Neither the plantar plating nor the dorsomedial plating technique was associated with injury to the insertion of the tibialis anterior muscle. Both studied techniques are safe, well-established procedures. Arthrodesis with plantar plating, however, offers additional advantages and is a reliable tool in the foot and ankle surgeon's repertoire.

Influence of angulation on metacarpal bone mineral density measurements using digital X-ray radiogrammetry.

OBJECTIVE: Digital X-ray radiogrammetry (DXR) is a computer-assisted technique used to quantify cortical bone density of the metacarpals. The influence of metacarpal bone rotation and type of cast material on bone mineral density (BMD) measurements using the DXR technique was tested. METHODS: The bone mineral density of the hand was measured by DXR, and rotation error (DXR-RE) as coefficients of variation were calculated, to verify reliability and reproducibility of this radiogeometric technique to assess in particular minor disease-related changes in the metacarpal bone mass. The reproducibility of the DXR measurements was also investigated using different cast materials (mull, elastic, and plastic). RESULTS: There were no significant changes in absolute values of DXR-BMD observed between 0 to [Formula: see text] angulation. The relative DXR-RE ranged between 0 % (degree 1) and 0.70 % (degrees 15 and 19) for DXR-BMD. Regarding the different cast materials, DXR-BMD revealed a coefficient of variation with 0.41 % (mull cast) and 0.21 % (elastic cast). For the plastic cast, the DXR technique was not able to perform an analysis of DXR-BMD. CONCLUSION: The study revealed no significant influence of metacarpal rotation on the measurements of metacarpal bone mineral density as estimated by DXR. DXR measurements are not optimal when cast material is used. DXR can accurately quantify periarticular cortical bone mass. This is significant especially for rheumatoid arthritis and related conditions where X-ray imaging of arthritic hands with varying degrees of deformity is performed.

Anatomical evaluation of different approaches for tibiotalocalcaneal arthrodesis.

BACKGROUND: The transfibular approach is commonly used for tibiotalocalcaneal arthrodesis. However, the medial and the posterolateral approaches are available as alternatives. The present study was performed to assess the effects of the 3 approaches on the neurovascular structures encountered and to quantify the extent of cartilage in the different joint compartments that could be surgically debrided. METHODS: This cadaver study was performed in 6 pairs of formalin-fixed legs (mean donor age: 80 years; 4 females, 2 males). For each approach, 4 specimens were selected. The neurovascular structures at risk and the debrided portions of the articular cartilage were compared. RESULTS: Arterial structures were least compromised by the transfibular approach. The posterolateral approach was particularly likely to damage the lateral malleolar branches of the peroneal artery. Venous structures were at risk mainly from the medial approach, which was also the most risk-bearing of the 3 approaches in terms of nerve damage. The proportions of cartilage-debrided joint surfaces of the tibia in the ankle joint, and of the talus and the calcaneus in the subtalar joint, did not differ notably. The proportions of debrided surfaces of the talus in the ankle joint differed notably among the 3 approaches. CONCLUSIONS: The medial approach could be a valid alternative to the lateral transfibular approach for tibiotalocalcaneal arthrodesis. Care should be taken, however, to prevent damage to the saphenous nerve and other neurological structures. CLINICAL RELEVANCE: Access morbidity and feasibility of adequate cartilage debridement are relevant to the clinical outcome of hindfoot arthrodesis.

Functional differentiation of the human lumbar perivertebral musculature revisited by means of muscle fibre type composition.

Human back muscles have been classified as local stabilizers, global stabilizers and global mobilizers. This concept is supported by the distribution of slow and fast muscle fibres in quadrupedal mammals, but has not been evaluated for humans because detailed information on the fibre type composition of their perivertebral musculature is rare. Moreover, such information is derived from spot samples, which are assumed to be representative for the respective muscle. In accordance with the proposed classification, numerous studies in animals indicate great differences in the fibre distribution within and among the muscles due to fibre type regionalization. The aims of this study were to (1) qualitatively explore the applicability of the proposed functional classification for human back muscles by studying their fibre type composition and (2) evaluate the representativeness of spot sampling techniques. For this, the fibre type distribution of the whole lumbar perivertebral musculature of two male cadavers was investigated three-dimensionally using immunohistochemistry. Despite great local variations (e.g., among fascicles), all muscles were composed of about 50% slow and 50% fast fibres. Thus, contradicting the concepts of lumbar muscle function, no functional differentiation of the muscles was observed in our study of the muscle contractile properties. The great similarity in fibre composition among the muscles equips each muscle equally well for a broad range of tasks and therefore has the potential to allow for great functional versatility of the human back musculature. Spot samples do not prove to be representative for the whole muscle. The great intraspecific variability observed previously in single-spot samples is potentially misleading.

Intramuscular architecture of the autochthonous back muscles in humans.

Many training concepts take muscle properties such as contraction speed or muscle topography into account to achieve an optimal training outcome. Thus far, the internal architecture of muscles has largely been neglected, although it is well known that parameters such as pennation angles or the lengths of fascicles but also the proportions of fleshy and tendinous fascicle parts have a major impact on the contraction behaviour of a muscle. Here, we present the most detailed description of the intramuscular fascicle architecture of the human perivertebral muscles available so far. For this, one adult male cadaver was studied. Our general approach was to digitize the geometry of each fascicle of the muscles of back proper (Erector spinae) - the Spinalis thoracis, Iliocostalis lumborum, Longissimus thoracis and the Multifidus thoracis et lumborum - and of the deep muscles of the abdomen - Psoas minor, Psoas major and Quadratus lumborum - during a layerwise dissection. Architectural parameters such as fascicle angles to the sagittal and the frontal planes as well as fascicle lengths were determined for each fascicle, and are discussed regarding their consequences for the function of the muscle. For example, compared with the other dorsovertebral muscles, the Longissimus thoracis can produce greater shortening distances because of its relatively long fleshy portions, and it can store more elastic energy due to both its relatively long fleshy and tendinous fascicle portions. The Quadratus lumborum was outstanding because of its many architectural subunits defined by distinct attachment sites and fascicle lengths. The presented database will improve biomechanical models of the human trunk by allowing the incorporation of anisotropic muscle properties such as the fascicle direction into finite element models. This information will help to increase our understanding of the functionality of the human back musculature, and may thereby improve future training concepts.

Dead bodies for the anatomical institute in the Third Reich: An investigation at the University of Jena.

During the period of 2004-2005, a group of anatomists and historians investigated the origin of dead bodies received by the anatomical institute of the University of Jena in the Third Reich. Between 1933 and 1945, the institute received the bodies of 203 executed persons, most of whom had been sentenced to death for relatively minor offenses or opposition to National Socialist (NS) regulations. Moreover, the institute received about 200 bodies of possible "euthanasia" victims from nearby nursing homes and mental institutions, and several dozen dead bodies of forced laborers from Eastern Europe. Many of these persons must be considered victims of NS injustice. One of the central questions of the investigation was whether any remains of NS victims were still present in the anatomical collections of the institute. At their own initiative, members of the anatomical institute initiated the investigation after a change of leadership at the institute. The investigation was characterized by (1) a scholarly approach thanks to the participation of expert historians, (2) transparency, including early and full information of the press, (3) documentation and publication of the results at the national and international level, (4) appropriate consequences for the anatomical collections, and (5) commemoration of the victims. This and other recent investigations demonstrate that a new generation of German anatomists has begun to uncover the role of their institutes during the Third Reich, finally overcoming the phase of silence in postwar German anatomy.

Imaging of lamination patterns of the adult human olfactory bulb and tract: in vitro comparison of standard- and high-resolution 3T MRI, and MR microscopy at 9.4 T.

PURPOSE: Neurological and smelling disorders (e.g. Alzheimer's disease, sinonasal disease) negatively affect the microstructural integrity of the olfactory bulb's (OB) cortical layers. Recovery processes depend on active restoration of this microstructural integrity enabled by neuroneogenesis in the OB. The aim of this study was to evaluate lamination patterns of the OB and adjacent tract (OT) using high resolution MRI at 3 Tesla (T) as well as MR microscopy at 9.4 T in comparison with histological sections. MATERIAL AND METHODS: Twenty-four human OBs were imaged in vitro using standard (2mm slice thickness) and high resolution (0.2mm slice thickness) T1w and T2w MR imaging at 3T. Based on signal intensity differences, the number of OB layers and the OB lamination patterns were assessed by two observers in consensus. Results were compared using Wilcoxon test. Signal intensity profiles were compared to reference Nissl stained histological sections and imaging results of MR microscopy. OT lamination patterns were assessed and different configurations of cross sectional areas were compared to macroscopic results and OB/OT lamination patterns. RESULTS: Standard resolution at 3T identified three layers in 8.3%, two layers in 83.3%, and one layer in 8.3%. High resolution at 3T (4 layers in 91.7%, 3 layers in 8.3%) significantly performed better (P<0.001). Signal intensity profile analysis at 3T and 9.4 T (yielding up to 6 different signal intensities) correlated with histological sections and enabled quantitative evaluation of OB lamination patterns. 3T MRI of the OT revealed two separate signal intensities in T2w in 73%, a hyperintense core and a hypointense sheath, and the number of OT signal intensities positively correlated (ρ=0.541, P=0.006) with the increasing complexity of the OTs' cross sectional area configurations. Additionally, cross sectional area configurations correlated with macroscopic results (ρ=0.558, P=0.002) and OB lamination patterns (ρ=0.446, P=0.022). CONCLUSIONS: 3T MRI and MR-microscopy indicate the possibility to identify the lamination pattern of the human OB/OT and to reflect the histological status. If further development will be able to provide technical equipment that complies with the condition of human in vivo high resolution imaging achieving a good enough signal noise ratio, the method of signal intensity profile analysis could prospectively enable scientists to assess the OB's microstructural status in neurological and smelling disorders.

Biomechanical characterization of an osteoporotic artificial bone model for the distal femur.

The treatment of osteoporotic distal femur fractures is still an unsolved problem of trauma surgery. The poor bone stock often leads to secondary loss of reduction and implant failure. Therefore, the development of new implants and their biomechanical testing is essential. In a previous study, we developed and initially characterized an artificial osteoporotic bone model of the distal femur. This follow-up study was performed to characterize this model in a biomechanical comparison. We investigated two different artificial bones: five foam cortical shell (Sawbones) and 10 custom-made artificial femoral condyles. Additionally, eight human femora were used for comparison. For biomechanical testing, two intramedullary nails (distal femur nail (DFN) and supracondylar nail (SCN)) were cyclically axial loaded in an AO 33 C2 unstable distal femoral fracture model. In our testing, the artificial bone showed a decrease in the axial stiffness of 27% for the SCN and 28% for the DFN compared to the human results. Also the number of cycles for a deformation of 2.5 mm was reduced by 55% (SCN) and 62% (DFN). This decrease was homogenous and caused by the relative high bone mineral density of the human specimen used. The modes of failure showed no difference between the artificial and human bones. Our customized artificial bone provides suitable results. In relation to the human bones classified as mildly osteoporotic, we assume that the biomechanical properties match to serve as an osteoporotic bone. Yet, we suggest to check transferability of the results with human material.

Reproducibility and influence of hand rotation on computer-aided joint space analysis.

OBJECTIVES: Computer-aided joint space analysis (CAJSA) is a recently developed, semi-automated tool to aid in the measurement of joint space margins based on hand radiographs. The objective of this study is to verify the potential effect of hand rotation during X-ray imaging on the measurement of joint space width using CAJSA and to evaluate the reproducibility of the CAJSA technique in healthy subjects and in patients with rheumatoid arthritis. METHODS: All joint space distance (JSD) measurements were performed using CAJSA-technology at the metacarpophalangeal articulation based on conventional and digital hand radiographs. RESULTS: I. Hand rotation showed an effect on the reproducibility with CV ranging between 0.39% (angulation 1°) and 1.66% (angulation 19°). II. Regarding the overall reproducibility of the CAJSA method, the intra-radiograph reproducibility of JSD was calculated with CV=0.54% for conventional images and CV=0.38% for digital images. The inter-radiograph reproducibility error was observed with CV=0.66% (conventional images) and CV=0.63% (digital images). III. The study revealed a reproducibility for CAJSA measurements in RA ranging between 0.37% (JSD-MCP ring finger; van der Heijde-modification of the Sharp method score 1) to 1.37% (JSD-MCP index finger; van der Heijde-modification of the Sharp method score 3). CONCLUSION: CAJSA measures JSD at the metacarpophalangeal articulation with high reproducibility in healthy subjects and in patients with differing stages of rheumatoid arthritis. Additional findings show that hand rotation during X-ray imaging has an impact on the CAJSA measurements; thus avoiding acquisition of hand radiographs with a rotation error of more than 15 degrees can be recommended.

In vitro comparison of water displacement method and 3 Tesla MRI for MR-volumetry of the olfactory bulb: which sequence is appropriate?

RATIONALE AND OBJECTIVES: Magnetic resonance imaging olfactory bulb (OB) volumetry (OBV) is already used as a complementary prognostic tool to assess olfactory disorders. However, a reference standard in imaging for OBV has not been established. The aim of this in vitro study was to compare volumetric results of different magnetic resonance sequences for OBV at 3 T to genuine OB volumes measured by water displacement. MATERIALS AND METHODS: The volumes of 15 human cadaveric OBs were measured using the water displacement method in this institutional review board-approved prospective study. The magnetic resonance imaging protocol at 3 T included constructive interference in steady state (CISS), T2-weighted (T2w) three-dimensional (3D) sampling perfection with application-optimized contrasts using different flip-angle evolutions (SPACE), T2w two-dimensional (2D) turbo spin-echo (TSE), and T1-weighted (T1w) 3D fast low-angle shot (FLASH) sequences. Two blinded observers independently performed two OB volumetric assessments per bulbus and sequence. Intraobserver and interobserver reliabilities were assessed by intraclass correlation coefficients. Bland-Altman plots were analyzed to evaluate systematic biases and concordance correlation coefficients to assess reproducibility. RESULTS: For both observers, intraclass correlation coefficient analysis yielded almost perfect results for intraobserver reliability (CISS, 0.94-0.98; T2w 3D SPACE, 0.93-0.98; T2w 2D TSE, 0.98-0.98; T1w 3D FLASH, 0.95-0.99). Interobserver reliability showed almost perfect agreement for all sequences (CISS, 0.98; T2w 3D SPACE, 0.89; T2w 2D TSE, 0.93; T1w 3D FLASH, 0.97). The CISS sequence yielded the highest mean concordance correlation coefficient (0.95) and the highest combination of precision (0.97) and accuracy (0.98) values. In comparison with the water displacement method, Bland-Altman analyses revealed the lowest systematic bias (-0.5%) for the CISS sequence, followed by T1w 3D FLASH (-1.3%), T2w 3D SPACE (-7.5%), and T2w 2D TSE (-10.9%) sequences. CONCLUSIONS: Compared to the water displacement method, the CISS sequence is suited best to validly and reliably measure OB volumes because of its highest values for accuracy and precision and lowest systematic bias.

Internal fixation of type-C distal femoral fractures in osteoporotic bone: surgical technique.

BACKGROUND: Fixation of distal femoral fractures remains a challenge, especially in osteoporotic bone. This study was performed to investigate the biomechanical stability of four different fixation devices for the treatment of comminuted distal femoral fractures in osteoporotic bone. METHODS: Four fixation devices were investigated biomechanically under torsional and axial loading. Three intramedullary nails, differing in the mechanism of distal locking (with two lateral-to-medial screws in one construct, one screw and one spiral blade in another construct, and four screws [two oblique and two lateral-to-medial with medial nuts] in the third), and one angular stable plate were used. All constructs were tested in an osteoporotic synthetic bone model of an AO/ASIF type 33-C2 fracture. Two nail constructs (the one-screw and spiral blade construct and the four-screw construct) were also compared under axial loading in eight pairs of fresh-frozen human cadaveric femora. RESULTS: The angular stable plate constructs had significantly higher torsional stiffness than the other constructs; the intramedullary nail with four-screw distal locking achieved nearly comparable results. Furthermore, the four-screw distal locking construct had the greatest torsional strength. Axial stiffness was also the highest for the four-screw distal locking device; the lowest values were achieved with the angular stable plate. The ranking of the constructs for axial cycles to failure was the four-screw locking construct, with the highest number of cycles, followed by the angular stable plate, the spiral blade construct, and two-screw fixation. The findings in the human cadaveric bone were comparable with those in the synthetic bone model. Failure modes under cyclic axial load were comparable for the synthetic and human bone models. CONCLUSIONS: The findings of this study support the concept that, for intramedullary nails, the kind of distal interlocking pattern affects the stabilization of distal femoral fractures. Four-screw distal locking provides the highest axial stability and nearly comparable torsional stability to that of the angular stable plate; the four-screw distal interlocking construct was found to have the best combined (torsional and axial) biomechanical stability.

Distal femur fractures of the elderly--different treatment options in a biomechanical comparison.

BACKGROUND: Fractures of the distal femur, especially in the elderly patient, are an unsolved problem in orthopaedic and trauma surgery. Poor bone stock quality caused by osteoporosis often results in bad implant anchorage in the distal part with a high risk of secondary failures such as cutout. This study investigates the biomechanical characteristics of four implants with different distal locking options under quasi-static torsional and cyclic axial loading. Therefore, an osteoporotic bone model simulating severe osteoporotic conditions was used. METHODS: Four different implants (T2 intramedullary nail, supracondylar nail (SCN), distal femoral nail (DFN) and the AxSOS angular stable plate) with different distal locking options were instrumented using an osteoporotic bone model. Five specimens per implant and per loading type (torsional and axial) were used. Mechanical testing was performed under physiologic loading conditions. First, a torsional test was performed in internal and external rotation (10 Nm), with a new specimen; a stepwise cyclic axial loading was conducted until failure of the construct. FINDINGS: For torsional loading, the lowest range of motion (ROM) and neutral zone (NZ) was found for the AxSOS plate construct. The SCN and T2 constructs showed similar results, and the highest ROM and NZ were found for the constructs treated with the DFN. Axial stiffness was highest for SCN constructs and in the same range for DFN and T2. The lowest stiffness showed in the AxSOS plate constructs with 47% of SCN stiffness. Under cyclic axial loading, the SCN constructs showed the highest number of cycles to failure, followed by AxSOS (70%), DFN (69%) and T2 (48%). INTERPRETATION: In conclusion of this biomechanical study, we can clinically suggest that, if, in general, torsional stability is required (e.g., for bedridden patients) the AxSOS plate will be sufficient. By contrast, the findings of this study support the fact that the SCN should be considered for mobile patients where early postoperative mobilisation for rehabilitation is desired.

Feasibility study of semi-automated measurements of finger joint space widths.

The purpose of this study is to evaluate technical feasibility based on image capturing conditions (film-focus distance (FFD), film sensitivity, film brand, exposure level and tube voltage) that potentially alter radiographs and consequently may influence the semi-automated measurement of joint space distance (JSD) by computer-aided joint space analysis (CAJSA) in rheumatoid arthritis and osteoarthritis. The radiographs of a left hand (deceased man) were acquired under systematically changing image capturing conditions (exposure level: 4-8 mAs; FFD: 90-130 cm; film sensitivity: 200/400 and tube voltage: 40-52 kV with different image modalities: conventional radiographs, original digital radiographs, digital print-outs). All JSD-measurements were performed with the CAJSA-technology (Radiogrammetry Kit, Version 1.3.6; Sectra; Sweden) at the metacarpal-phalangeal articulation. JSD-analysis was not influenced by changes of FFD, exposure level, film sensitivity or film brand. JSD showed significant variation caused by tube voltage (conventional: CV = 1.913% for Agfa and CV = 2.448% for Kodak; digital: CV = 0.741% for Philips print-outs and CV = 0.620% with original digital images versus CV = 2.185% for Siemens print-outs and 0.951% with original digital images). Computer-aided joint space analysis for JSD-measurements is unaffected by the following image capturing parameters: film-focus distance, film sensitivity, film brand and exposure level. An influence of tube voltage was detected in a lesser extent for original digital images compared to the printed digital as well as conventional versions. Consequently, a standardized tube voltage is essential for accurate reproductions of CAJSA-measurements in rheumatoid arthritis and osteoarthritis.

Evaluation of a customized artificial osteoporotic bone model of the distal femur.

In the development of new implants biomechanical testing is essential. Since human bones vary markedly in density and geometry their suitability for biomechanical testing is limited. In contrast artificial bones are of great uniformity and therefore appropriate for biomechanical testing. However, the applied artificial bones have to be proved as comparable to human bone. An anatomical shaped artificial bone representing the distal human femur was created by foaming polyurethane. To get a bone model with properties of osteoporotic bone a foam density of 150 kg/m3 was used. The biomechanical properties of our artificial bones were evaluated against eight mildly osteoporotic fresh frozen human femora by mechanical testing. At the artificial bones all tested parameters showed a very small variation. In contrast significant correlation between bone mass density and tested parameters was found for the human bones. The artificial bones reached 39% of the compression strength and 41% of the screw pullout force of the human bone. In indentation testing the artificial bones reached 27% (cancellous) and 59% (cortical) respectively of the human bones strength. Regarding Shore hardness artificial bone and human bone showed comparable results for the cortical layer and at the cancellous layer the artificial bone reached 57% of human bones hardness. Our described method for customizing of artificial bones regarding their shape and bone stock quality provides suitable results. In relation to the as mildly osteoporotic classified human bones we assume that the biomechanical properties matching to serve osteoporotic bone.

Plantar versus dorsomedial locked plating for Lapidus arthrodesis: a biomechanical comparison.

BACKGROUND: Lapidus arthrodesis with a plate and a compression screw is an established procedure in hallux valgus surgery. The present study was performed to investigate the potential benefit of a compression screw combined with a plantarly applied angle-stable, anatomically precontoured plate or a dorsomedially applied angle-stable plate. METHODS: In six pairs of human cadaver specimens, one specimen each was randomized to receive a dorsomedial H-shaped plate, while the other received a plantar plate. Bone mineral density was measured with peripheral quantitative computed tomography. The specimens were loaded quasi-statically, followed by cyclic loading. Finally, they were loaded to failure. In the static tests, stiffness and range of motion (ROM) data were obtained. In the cyclic tests, the constructs' displacement was studied. In the load-to-failure test, stiffness and maximum load to failure were measured. RESULTS: The two groups did not differ significantly with regard to BMD (p = 0.25). Any significant differences observed were in favor of the plantar constructs, which had greater initial stiffness (p = 0.028) and final stiffness (p = 0.042), a smaller ROM (p = 0.028), and a greater load to failure (p = 0.043). There was no significant difference regarding displacement (p = 0.14). CONCLUSION: In the static tests, the plantar angle-stable plate construct was superior to the dorsomedial angle-stable plate construct. CLINICAL RELEVANCE: Plantar plating appears to offer biomechanical benefit. Clinical studies will be required to show whether this translates into earlier resumption of weightbearing and into lower rates of nonunion.

[Release of the lateral plantar nerve in case of entrapment]. / Neurolyse des Nervus plantaris lateralis zur Behandlung des Nervenengpasssyndroms am Rückfuss.

OBJECTIVE: Reduction of heel pain by neurolysis of the lateral plantar nerve. Indications Contraindications Surgical Technique Postoperative Management Results INDICATIONS: Heel pain due to an entrapment of the lateral plantar nerve. CONTRAINDICATIONS: Acute inflammatory alterations in the foot. Skin laceration at the medial hindfoot. Relative: heel pain, which could not be assigned to a distinct diagnosis. Relative: flatfoot deformity with hindfoot valgus. SURGICAL TECHNIQUE: Regional anesthesia. Supine position. Tourniquet. Curved skin incision behind the medial malleolus to the medioplantar aspect of the heel. Incision of the flexor retinaculum and careful dissection of the tibial nerve, until the medial and lateral plantar nerves can be clearly identified. Stepwise decompression of the lateral plantar nerve along its course to the medial aspect of the heel. Exposure of the first branch of the lateral plantar nerve (Baxter's nerve) by dissection of the fascia overlying the quadratus plantae muscle and the flexor digitorum brevis muscle. Release of the tourniquet and hemostasis. Wound closure in layers. Below-knee splint in neutral position of the ankle. POSTOPERATIVE MANAGEMENT: Elevation of the concerned leg. Mobilization without weight bearing during the first 5 days. Stepwise increased weight bearing according to the pain level. Soft insoles for 12 weeks. No running or jumping for 12 weeks. RESULTS: From 2006 to 2008, twelve patients (ten women, two men) were treated with a neurolysis of the lateral plantar nerve. In nine patients, the diagnosis was confirmed neurologically; in three patients, the authors decided to perform the nerve decompression due to clinical findings. The patients were followed up clinically (mean follow-up 15 months) and were asked to estimate their pain level with the visual analog scale (VAS). There were no postoperative complications. One patient developed a complex regional pain syndrome. Pain level decreased significantly within 6 weeks (VAS preoperatively 7.9; VAS postoperatively 3.8) and showed a further pain reduction to VAS 2.1 after 9 months. Two patients complained of recurrent symptoms after a mean of 11 months. In these patients, the initial diagnosis could not be confirmed by electrophysiological measurements.