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Knee Surgery, Sports Traumatology,... Dec 2023The aim of this study was to assess the biomechanical effects of subtalar ligament injury and reconstruction on stability of the subtalar joint in all three spatial...
PURPOSE
The aim of this study was to assess the biomechanical effects of subtalar ligament injury and reconstruction on stability of the subtalar joint in all three spatial planes.
METHODS
Fifteen fresh frozen cadaveric legs were used, with transfixed tibiotalar joints to isolate motion to the subtalar joint. An arthrometer fixed to the lateral aspect of the calcaneus measured angular displacement in all three spatial planes on the inversion and eversion stress tests. Stress manoeuvres were tested with the intact joint, and then repeated after sequentially sectioning the inferior extensor retinaculum (IER), cervical ligament (CL), interosseous talocalcaneal ligament (ITCL), arthroscopic graft reconstruction of the ITCL, and sectioning of the calcaneo-fibular ligament (CFL).
RESULTS
Sectioning the ITCL significantly increased angular displacement upon inversion and eversion in the coronal and sagittal planes. Reconstruction of the ITCL significantly improved angular stability against eversion in the axial and sagittal planes, and against inversion in the axial and coronal planes, at the zero time point after reconstruction. After sectioning the CFL, resistance to eversion decreased significantly in all three planes.
CONCLUSION
Progressive injury of ligamentous stabilisers, particularly the ITCL, led to increasing angular displacement of the subtalar joint measured with the inversion and eversion stress tests, used in clinical practice. Reconstruction of the ITCL using tendon graft significantly stabilised the subtalar joint in the axial and sagittal planes against eversion and in the axial and coronal planes against inversion, immediately after surgery.
Topics: Humans; Subtalar Joint; Biomechanical Phenomena; Cadaver; Ankle Joint; Ligaments, Articular; Joint Instability; Allografts
PubMed: 37955675
DOI: 10.1007/s00167-023-07622-6 -
Scientific Reports Apr 2021The myodural bridge (MDB) connects the suboccipital musculature to the spinal dura mater (SDM) as it passed through the posterior atlanto-occipital and the atlanto-axial...
The myodural bridge (MDB) connects the suboccipital musculature to the spinal dura mater (SDM) as it passed through the posterior atlanto-occipital and the atlanto-axial interspaces. Although the actual function of the MDB is not understood at this time, it has recently been proposed that head movement may assist in powering the movement of cerebrospinal fluid (CSF) via muscular tension transmitted to the SDM via the MDB. But there is little information about it. The present study utilized dogs as the experimental model to explore the MDB's effects on the CSF pressure (CSFP) during stimulated contractions of the suboccipital muscles as well as during manipulated movements of the atlanto-occiptal and atlanto-axial joints. The morphology of MDB was investigated by gross anatomic dissection and by histological observation utilizing both light microscopy and scanning electron microscopy. Additionally biomechanical tensile strength tests were conducted. Functionally, the CSFP was analyzed during passive head movements and electrical stimulation of the suboccipital muscles, respectively. The MDB was observed passing through both the dorsal atlanto-occipital and the atlanto-axial interspaces of the canine and consisted of collagenous fibers. The tensile strength of the collagenous fibers passing through the dorsal atlanto-occipital and atlanto-axial interspaces were 0.16 ± 0.04 MPa and 0.82 ± 0.57 MPa, respectively. Passive head movement, including lateral flexion, rotation, as well as flexion-extension, all significantly increased CSFP. Furthermore, the CSFP was significantly raised from 12.41 ± 4.58 to 13.45 ± 5.16 mmHg when the obliques capitis inferior (OCI) muscles of the examined specimens were electrically stimulated. This stimulatory effect was completely eliminated by severing the myodural bridge attachments to the OCI muscle. Head movements appeared to be an important factor affecting CSF pressure, with the MDB of the suboccipital muscles playing a key role this process. The present study provides direct evidence to support the hypothesis that the MDB may be a previously unappreciated significant power source (pump) for CSF circulation.
Topics: Animals; Atlanto-Occipital Joint; Biomechanical Phenomena; Cervical Vertebrae; Dogs; Microscopy, Electron, Scanning; Neck Muscles
PubMed: 33850172
DOI: 10.1038/s41598-021-86934-4 -
Orthopaedic Surgery Dec 2022Understanding the morphology of the distal femur is essential for improving bone-implant match in total knee arthroplasty (TKA) and understanding the mechanisms behind...
OBJECTIVE
Understanding the morphology of the distal femur is essential for improving bone-implant match in total knee arthroplasty (TKA) and understanding the mechanisms behind knee kinematics. However, little is known about the asymmetry of the posterior condyles. Thus, this study aimed to thoroughly investigate asymmetries in sizes and shapes between the medial and lateral posterior condyles before and after femoral resections during TKA in osteoarthritic (OA) knees.
METHODS
Three-dimensional femoral models of 74 OA knees were constructed using computed tomography images. The morphologic measurements of the posterior condyle pre- and post-simulated osteotomy for TKA included the radii of the posterior condyles fitted to a circle on the sagittal and axial planes of the femoral coordinate system, the inclination angle of the articular surface and resected surface, and the width and height of the resected surface. Differences in the data were assessed using Student's t-test, and correlations were evaluated using the Pearson product-moment correlation.
RESULTS
The radii of the medial posterior condyles fitted to the circle were, on average, 6 mm larger than those of the lateral condyles on the axial plane (p < 0.001) and 0.7 mm smaller than those of the lateral condyles on the sagittal plane (p = 0.046). The inclination angles of the medial and lateral posterior condyles on the axial plane were significantly different with both pre-simulated and post-simulated osteotomy, respectively (both p < 0.001). The resected plane of the lateral posterior condyles displaced opposite inclination directions between the distal and proximal portions. Neither heights or widths of the medial posterior condyles were significantly different from those of their lateral counterparts (both p > 0.107).
CONCLUSIONS
This study found asymmetrical inclination of the resected surface and coronal radii between the medial and lateral posterior condyles, which may relate to the posterolateral overhang of the lateral condyle after TKA and the progression of the knee OA. These findings provides valuable morphological information and may help improve the implant designs for TKA.
Topics: Humans; Arthroplasty, Replacement, Knee; Femur; Osteoarthritis, Knee
PubMed: 36346140
DOI: 10.1111/os.13529 -
Journal of Anatomy Mar 2020The monobasal pectoral fins of living coelacanths and lungfishes are homologous to the forelimbs of tetrapods and are thus critical to investigate the origin thereof....
The monobasal pectoral fins of living coelacanths and lungfishes are homologous to the forelimbs of tetrapods and are thus critical to investigate the origin thereof. However, it remains unclear whether the similarity in the asymmetrical endoskeletal arrangement of the pectoral fins of coelacanths reflects the evolution of the pectoral appendages in sarcopterygians. Here, we describe for the first time the development of the pectoral fin and shoulder girdle in the extant coelacanth Latimeria chalumnae, based on the tomographic acquisition of a growth series. The pectoral girdle and pectoral fin endoskeleton are formed early in development with a radially outward growth of the endoskeletal elements. The visualization of the pectoral girdle during development shows a reorientation of the girdle between the fetus and pup 1 stages, creating a contact between the scapulocoracoids and the clavicles in the ventro-medial region. Moreover, we observed a splitting of the pre- and post-axial cartilaginous plates in respectively pre-axial radials and accessory elements on one hand, and in post-axial accessory elements on the other hand. However, the mechanisms involved in the splitting of the cartilaginous plates appear different from those involved in the formation of radials in actinopterygians. Our results show a proportional reduction of the proximal pre-axial radial of the fin, rendering the external morphology of the fin more lobe-shaped, and a spatial reorganization of elements resulting from the fragmentation of the two cartilaginous plates. Latimeria development hence supports previous interpretations of the asymmetrical pectoral fin skeleton as being plesiomorphic for coelacanths and sarcopterygians.
Topics: Animal Fins; Animals; Biological Evolution; Fishes; Fossils; Skeleton
PubMed: 31713843
DOI: 10.1111/joa.13115 -
Journal of Pediatric Orthopedics Feb 2021Trochlear dysplasia is a known risk factor for patellar dislocations yet normal trochlea development is not well described. This study will define the articular...
INTRODUCTION
Trochlear dysplasia is a known risk factor for patellar dislocations yet normal trochlea development is not well described. This study will define the articular cartilage (AC) and subchondral trochlear morphology development in pediatric patients using magnetic resonance imaging (MRI) evaluation.
METHODS
A retrospective knee MRI review included patients aged 3 to 16 years with nonpatellofemoral-related diagnoses. International classification of diseases-9/International classification of diseases-10 codes were used to identify eligible study patients. Measurements of the trochlea were made on the basis of previously established methods using the axial MRI just distal to the physis at the deepest portion of the trochlear groove. Three linear [lateral trochlear height (LTH), medial trochlear height (MTH), and central trochlear height (CTH)] and 3 angular [sulcus angle (SA), lateral trochlear slope (LTS), and medial trochlear slope (MTS)] were made at AC and subchondral bone (SCB). The 12 measurements were made independently by 2 study authors. Inter-rater reliability was assessed using an interclass correlation coefficient for absolute agreement to the average of the scores. Trochlea measurements were summarized across age quartiles defined as first quartile (age, 5.1 to 8.3 y), second quartile (8.3 to 11.5 y), third quartile (11.5 to 14.3 y), fourth quartile (14.3to 16.9 y). Associations between age and trochlea measures were assessed using linear regression with Huber-White-adjusted SEs to account for clustering from a small number of patients (N=16) with >1 MRI.
RESULTS
In total, 246 knee MRIs from 230 patients were included in this study; 113 patients (51%) were female, whereas 117 (49%) were male. A total of 116 MRIs (47%) were of the left knee and 130 (53%) were right knee. The average patient age was 11.4±3.4 years. Inter-rater agreement was high across all measures with interclass correlation coefficient values >0.7. Mean values for measurements are presented by age quartiles. LTH, MTH, and CTH showed a linear increase with age (range, 2 to 2.6 cm/y; P<0.001). SA, LTS, MTS measured at AC showed no change with age (P>0.05); however, LTS and MTS measured at SCB showed significant increases with age (0.6 and 0.9 degrees/y; P<0.001), whereas SA showed a decrease with age (-1.4 degrees/y; P<0.001). There were no significant differences found in the age associations by laterality, left versus right. There were no sex differences in the age associations for SA, LTS (P>0.05); however, for MTH, LTH, and CTH, males were found to have a significantly greater growth rate (P<0.001).
CONCLUSIONS
This study found an increase in AC and SCB MTH, LTH, and CTH over time, as well as an increase in SCB LTS and MTS, with a decrease in SA. However, AC of the LTS and SA remained constant, with no significant change throughout growth. This normative data indicate that the LTS and SA of AC are predictors of final trochlea shape in normal development. Final trochlear morphologic development is nearly complete around age 12 years, with no significant changes occurring thereafter.
Topics: Adolescent; Bone Diseases, Developmental; Cartilage, Articular; Child; Child, Preschool; Female; Growth Plate; Humans; Joint Instability; Knee Joint; Magnetic Resonance Imaging; Male; Reproducibility of Results; Retrospective Studies; Sex Characteristics
PubMed: 33229963
DOI: 10.1097/BPO.0000000000001697 -
RMD Open Dec 2022Inflammatory back pain (IBP) is a characteristic clinical symptom of patients with axial spondyloarthritis (axSpA) that is caused by inflammation in the axial skeleton....
Inflammatory back pain (IBP) is a characteristic clinical symptom of patients with axial spondyloarthritis (axSpA) that is caused by inflammation in the axial skeleton. In early disease stages the sacroiliac joints (SIJ) are most often affected, the spine usually at later stages. In many but clearly not all cases of axSpA new bone formation in form of syndesmophytes and ankylosis occur in the further course of the disease. Function and mobility may be impaired by both, inflammation and structural changes. In clinical trials outcome parameters most often used refer to pain, disease activity, function, mobility and global health but many researchers are also interested in radiographic progression in the axial skeleton of patients with axSpA. This viewpoint discusses the relevance of structural changes in the SIJ in comparison to the spine and in relation to functional outcomes and mobility.
Topics: Humans; Sacroiliac Joint; Spondylarthritis; Magnetic Resonance Imaging; Inflammation; Axial Spondyloarthritis
PubMed: 36517187
DOI: 10.1136/rmdopen-2022-002822 -
Acta Orthopaedica Et Traumatologica... Mar 2022This study aimed to investigate whether disruption of the repaired nuchal ligament (NL) affects clinical outcomes following posterior cervical spine surgery.
OBJECTIVE
This study aimed to investigate whether disruption of the repaired nuchal ligament (NL) affects clinical outcomes following posterior cervical spine surgery.
METHODS
This retrospective study included 101 patients (65 males, 36 females) who underwent posterior cervical spine surgery, 69 of whom received laminoplasty (LP), and 32 posterior decompression and fusion (PDF). The NL was split during the surgical approach and repaired at the time of wound closure. The frequency and spinal levels of NL disruption at one month, six months, and one year postoperatively were evaluated on mid-sagittal and axial magnetic resonance images. Postoperative axial symptoms, Neck Disability Index, T1 slope, flexion and extension angle, C2-C7 lordotic angle, and decrease rate of C2-C7 range of motion (ROM) were examined at six months and/or one year postoperatively. Based on the NL disruption levels, the patients were divided into the upper group (C2-C5), lower group (C6-T1), and non-disruption group.
RESULTS
Although the lower group contained patients with NL disruption (10%) after LP at final follow-up, all PDF patients belonged to the non-disruption group. For the LP patients, the postoperative axial symptoms, Neck Disability Index, T1 slope, flexion and extension angle, and C2-C7 lordotic angle did not significantly differ between the lower and non-disruption groups; however, the rate of C2-C7 ROM decrease in the lower group (48%) was considerably larger than that in the non-disruption group (33%) after LP.
CONCLUSION
Evidence from this study has shown that postoperative disruption of the repaired NL has no significant effect on postoperative axial symptoms and C2-C7 alignment, but it can affect the rate of decrease in C2-C7 ROM after LP.
LEVEL OF EVIDENCE
Level III, Therapeutic Study.
Topics: Cervical Vertebrae; Female; Humans; Laminoplasty; Ligaments; Male; Retrospective Studies; Treatment Outcome
PubMed: 35416166
DOI: 10.5152/j.aott.2022.21217 -
Proceedings. Biological Sciences Mar 2021Bird necks display unparalleled levels of morphological diversity compared to other vertebrates, yet it is unclear what factors have structured this variation. Using...
Bird necks display unparalleled levels of morphological diversity compared to other vertebrates, yet it is unclear what factors have structured this variation. Using three-dimensional geometric morphometrics and multivariate statistics, we show that the avian cervical column is a hierarchical morpho-functional appendage, with varying magnitudes of ecologically driven osteological variation at different scales of organization. Contrary to expectations given the widely varying ecological functions of necks in different species, we find that regional modularity of the avian neck is highly conserved, with an overall structural blueprint that is significantly altered only by the most mechanically demanding ecological functions. Nevertheless, the morphologies of vertebrae within subregions of the neck show more prominent signals of adaptation to ecological pressures. We also find that both neck length allometry and the nature of neck elongation in birds are different from other vertebrates. In contrast with mammals, neck length scales isometrically with head mass and, contrary to previous work, we show that neck elongation in birds is achieved predominantly by increasing vertebral lengths rather than counts. Birds therefore possess a cervical spine that may be unique in its versatility among extant vertebrates, one that, since the origin of flight, has adapted to function as a surrogate forelimb in varied ecological niches.
Topics: Animals; Biological Evolution; Birds; Cervical Vertebrae; Mammals; Neck; Phylogeny
PubMed: 33653136
DOI: 10.1098/rspb.2020.3150 -
Joint Diseases and Related Surgery 2022The aim of this study was to compare the stability of a novel biplanar distal humerus plate with the single- and double-columns J-plating techniques.
OBJECTIVES
The aim of this study was to compare the stability of a novel biplanar distal humerus plate with the single- and double-columns J-plating techniques.
MATERIALS AND METHODS
Eighteen sawbones humera were divided into three groups. In Groups 1, 2 and 3, biplanar plate, single lateral J-plate and double J-plate, were used, respectively. Transverse osteotomies at the upper portion of the olecranon fossa were made. Blocks of 10-mm was removed from each sample. Axial, torsional, and extensional stiffness of each group were measured.
RESULTS
The mean axial stiffness values in Groups 1, 2, and 3 were 64.80±6.75, 33.70±5.71, and 171.48±9.53 N/mm, respectively. Group 1 demonstrated a statistically significant difference compared to Group 2 (p=0.032), whereas Group 3 showed a statistically significant difference compared to Groups 1 and 2 (p=0.025 and p=0.014, respectively). The mean torsional stiffness values of Groups 1, 2, and 3 were 0.23±0.01, 0.14±0.008, and 0.30±0.007 N/ degree, respectively. Groups 1 and 3 demonstrated a statistically significant difference compared to Group 2 (p=0.042 and p=0.028, respectively). No statistically significant difference was detected between Groups 1 and 3 (p=0.27). The mean extensional bending stiffness values of Groups 1, 2 and 3 were 2.64±0.31, 1.17±0.13, and 3.2±0.1 N/mm, respectively. Group 1 demonstrated a statistically significant difference compared to Group 2 (p=0.041). There was no statistically significant difference between Groups 1 and 3 (p=0.083).
CONCLUSION
Biplanar plate allows applying enough numbers of long sagittal screws and offers more biomechanical stability than lateral column J-plate and in some aspects strong as dual J-plating in torsional and bending tests.
Topics: Biomechanical Phenomena; Bone Plates; Elbow Joint; Fracture Fixation, Internal; Humerus
PubMed: 35852193
DOI: 10.52312/jdrs.2022.604 -
PloS One 2020Percutaneous osseointegrated (OI) implants are increasingly viable as an alternative to socket suspension of prosthetic limbs. Upper extremity prostheses have also...
Percutaneous osseointegrated (OI) implants are increasingly viable as an alternative to socket suspension of prosthetic limbs. Upper extremity prostheses have also become more complex to better replicate hand and arm function and attempt to recreate pre-amputation functional levels. With more functionality comes heavier devices that put more stress on the bone-implant interface, which could be an issue for implant stability. This study quantified transhumeral loading at defined amputation levels using four simulated prosthetic limb-types: (1) body powered hook, (2) myoelectric hook, (3) myoelectric hand, and (4) advanced prosthetic limb. Computational models were constructed to replicate the weight distribution of each prosthesis type, then applied to motion capture data collected during Advanced Activities of Daily Living (AADLs). For activities that did not include a handheld weight, the body powered prosthesis bending moments were 13-33% (range of means for each activity across amputation levels) of the intact arm moments (reference 100%), torsional moments were 12-15%, and axial pullout forces were 30-40% of the intact case (p≤0.001). The myoelectric hook and hand bending moments were 60-99%, torsional moments were 44-97%, and axial pullout forces were 62-101% of the intact case. The advanced prosthesis bending moments were 177-201%, torsional moments were 164-326%, and axial pullout forces were 133-185% of the intact case (p≤0.001). The addition of a handheld weight for briefcase carry and jug lift activities reduced the overall impact of the prosthetic model itself, where the body powered forces and moments were much closer to those of the intact model, and more complex prostheses further increased forces and moments beyond the intact arm levels. These results reveal a ranked order in loading magnitude according to complexity of the prosthetic device, and highlight the importance of considering the patient's desired terminal device when planning post-operative percutaneous OI rehabilitation and training.
Topics: Artificial Limbs; Biomechanical Phenomena; Bone-Implant Interface; Humans; Humerus; Osseointegration; Torsion, Mechanical; Weight-Bearing
PubMed: 32760149
DOI: 10.1371/journal.pone.0237179