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BMC Veterinary Research Feb 2021French bulldogs exhibit significantly larger femoral external rotation and abduction than other breeds. We were curious as to whether this peculiar leg kinematic affects...
BACKGROUND
French bulldogs exhibit significantly larger femoral external rotation and abduction than other breeds. We were curious as to whether this peculiar leg kinematic affects patellar motion and/or might induce medial patellar subluxation (MPSL) or medial patellar permanent luxation (MPPL). We hypothesized that the more abducted leg posture during stance causes an unusual medial pull direction of the rectus femoris muscle during stance, and that this may facilitate the occurrence of MPSL or even MPPL during locomotion. To test our hypothesis, we analyzed existing stifle-joint X-ray-sequences collected during the treadmill walk and trot of seven adult female French bulldogs. We estimated 3D-patellar kinematics using Scientific Rotoscoping.
RESULTS
The three-dimensional motion of the patella comprises rotations and translations. From the seven dogs analyzed, three exhibited MPSL and one MPPL during the gait cycle. Medial patellar luxation (MPL) occurred mostly around toe-off in both gaits studied. Patellar position was generally not gait-related at the analyzed timepoints. In dogs with MPL, the patella was placed significantly more distally (p = 0.037) at touch-down (TD) and at midswing (p = 0.024), and significantly more medial at midswing (p = 0.045) compared to dogs without MPL.
CONCLUSIONS
Medial patellar luxation seems to be the consequence of the far from parasagittal position of the stifle joint during stance due to a broad trunk, and a wide pelvis. This peculiar leg orientation leads to a medial sideway pull caused by the rectus femoris muscle and the quadriceps femoris and may initiate plastic deformation of the growing femur and tibia. Thus, a way to avoid MPL could be to control breeding by selecting dogs with lean bodies and narrow pelvis. Actual breeding control programs based on the orthopedic examination are susceptible to errors. Systematic errors arise from the fact that the grading system is highly dependent on the dog's condition and the veterinarians' ability to perform the palpation on the stifle. Based on our results, the position of the patella at TD, or even perhaps during stand might offer a possibility of an objective radioscopic diagnostic of the MPL.
Topics: Animals; Biomechanical Phenomena; Dogs; Female; Gait; Patella; Patellar Dislocation; Radiography; Species Specificity; Stifle
PubMed: 33579272
DOI: 10.1186/s12917-021-02787-z -
Orthopaedic Surgery Feb 2024The knee is the most complex joint in the human body, including bony structures like the femur, tibia, fibula, and patella, and soft tissues like menisci, ligaments,... (Review)
Review
The knee is the most complex joint in the human body, including bony structures like the femur, tibia, fibula, and patella, and soft tissues like menisci, ligaments, muscles, and tendons. Complex anatomical structures of the knee joint make it difficult to conduct precise biomechanical research and explore the mechanism of movement and injury. The finite element model (FEM), as an important engineering analysis technique, has been widely used in many fields of bioengineering research. The FEM has advantages in the biomechanical analysis of objects with complex structures. Researchers can use this technology to construct a human knee joint model and perform biomechanical analysis on it. At the same time, finite element analysis can effectively evaluate variables such as stress, strain, displacement, and rotation, helping to predict injury mechanisms and optimize surgical techniques, which make up for the shortcomings of traditional biomechanics experimental research. However, few papers introduce what material properties should be selected for each anatomic structure of knee FEM to meet different research purposes. Based on previous finite element studies of the knee joint, this paper summarizes various modeling strategies and applications, serving as a reference for constructing knee joint models and research design.
Topics: Humans; Finite Element Analysis; Knee Joint; Femur; Tibia; Patella; Biomechanical Phenomena
PubMed: 38174410
DOI: 10.1111/os.13980 -
Magnetic Resonance in Medical Sciences... Jul 2018Peripatellar fat pads are intracapsular extrasynovial adipose cushions that accommodate the changing shape and volume of articular spaces during movement. Variations in... (Review)
Review
Peripatellar fat pads are intracapsular extrasynovial adipose cushions that accommodate the changing shape and volume of articular spaces during movement. Variations in bone geometry, passive and active stabilization mechanisms and/or functional demands may lead to peripatellar fat pad abnormalities. While peripatellar fat pads may be affected a variety of conditions such as synovial inflammation, tumor and fibrosis, a mechanical origin should also be considered. Commonly, the clinical term "impingement" is used synonymously in the radiological literature to refer to three distinct entities of structural peripatellar fat pad abnormalities: superolateral the infrapatellar fat pad (Hoffa fat pad) edema, suprapatellar fat pad edema, and prepatellar fat pad edema, implying a mechanical origin of these conditions. The aim of this pictorial review is to describe the normal anatomy of the extensor mechanism of the knee, and discuss the relation of patellofemoral maltracking to the above-mentioned peripatellar fat pad conditions based on current evidence.
Topics: Adipose Tissue; Edema; Female; Femur; Humans; Joint Diseases; Knee Joint; Magnetic Resonance Imaging; Male; Patella
PubMed: 28993563
DOI: 10.2463/mrms.rev.2017-0063 -
Cartilage Dec 2021In order to appreciate the roles articular cartilage of sesamoid bones and sesamoid fibrocartilage play in anatomy and pathology, the articular cartilage of the patella...
OBJECTIVE
In order to appreciate the roles articular cartilage of sesamoid bones and sesamoid fibrocartilage play in anatomy and pathology, the articular cartilage of the patella ( = 4) and suprapatella ( = 4) (a sesamoid fibrocartilage) of 12 to 14 weeks old New Zealand rabbits were studied qualitatively and quantitatively.
DESIGN/METHOD
The intact knee joints and block specimens from the joints were imaged using microscopic magnetic resonance imaging (µMRI) at a 97.6-µm pixel resolution for the former and 19.5-µm resolution for the latter. Histological sections were made out of the µMRI-imaged specimens, which were imaged using polarized light microscopy (PLM) at 0.25-, 1-, and 4-µm pixel resolutions.
RESULTS
The patella cartilage varied in thickness across the medial to lateral ends of the sesamoid bone with the central medial aspect slightly thicker than the lateral aspect. The suprapatella fibrocartilage decreased proximally away from the knee joint. Quantitative results of patellar cartilage showed strong dependence of fiber orientation with the tissue depth. Three histological zones can be clearly observed, which are similar to articular cartilage from other large animals. The sesamoid fibrocartilage has one thin surface layer (10 µm thick) of parallel-arranged structured fibers followed immediately by the majority of random fibers in bulk tissue. T2 relaxation time anisotropy was observed in the patellar cartilage but not in the bulk fibrocartilage.
CONCLUSION
Given the different functions of these 2 different types of cartilages in joint motion, these quantitative results will be beneficial to future studies of joint diseases using rabbits as the animal model.
Topics: Animals; Cartilage, Articular; Knee Joint; Magnetic Resonance Imaging; Microscopy, Polarization; Patella; Rabbits
PubMed: 33550833
DOI: 10.1177/1947603521990882 -
Orthopaedic Surgery Nov 2016To demonstrate the effect of the screw-home motion on the stability of the patellofemoral joint, and investigate its mechanism of regulation of patellar tracking.
OBJECTIVE
To demonstrate the effect of the screw-home motion on the stability of the patellofemoral joint, and investigate its mechanism of regulation of patellar tracking.
METHODS
Twenty volunteers who met the criteria were examined. All subjects had axial computed tomography (CT) scanning performed on bilateral knees at 0° and 30° of flexion. Scanning began above the femorotibial articulation and femoral trochlear groove, and moved sequentially down to the level of the anterior tibial tubercle. The following measurements were obtained: tibial rotation relative to the femur (TRRF), tibial tuberosity-trochlear groove (TT-TG) distance, lateral patellar displacement (LPD), patellar tilt angle (PTA), and congruence angle (CA). We assessed the change (Δ) in each variable at both flexion angles, and analyzed this to investigate the corresponding relationship between the patella, the femur, and the screw-home mechanism. The differences between the values measured at 0° and those measured at 30° flexion were analyzed using the paired sample t-test. The differences between men and women were analyzed using the t-test. Pearson's correlations were performed to determine the relationship between ΔTT-TG distance and ΔLPD, ΔPTA and ΔTRRF, and ΔCA and ΔTRRF.
RESULTS
There were 10 women and 10 men enrolled in the present study, with an average age of 25 years and an average body mass index of 21.8 kg/m , and all volunteers had no history of knee injuries. Compared with measurements taken at 0° flexion, TRRF at 30° flexion was significantly increased, and the PTA, CA, LPD, and TT-TG distance were significantly decreased (all P < 0.01). There was no difference between men and women at 0° and 30° flexion, respectively (P < 0.01). In this respect, there was no sex difference, but the change was greater for men than for women. Both ΔPTA and ΔCA demonstrated significant correlation with the ΔTRRF (both P < 0.01); a significant correlation between ΔLPD and ΔTT-TG distance was also demonstrated (P < 0.01).
CONCLUSIONS
As the tibiofemoral joint rotated, the patellofemoral joint became more stable and aligned, which indicates that the screw-home mechanism plays an important role in regulating patellofemoral joint alignment.
Topics: Adult; Biomechanical Phenomena; Female; Femur; Healthy Volunteers; Humans; Male; Patella; Patellofemoral Joint; Range of Motion, Articular; Rotation; Tibia; Tomography, X-Ray Computed
PubMed: 28032709
DOI: 10.1111/os.12295 -
Orthopaedic Surgery Apr 2021To aim of the present paper was to introduce a novel fixation technique for the treatment of inferior pole fracture of the patella. We performed a prospective... (Observational Study)
Observational Study
To aim of the present paper was to introduce a novel fixation technique for the treatment of inferior pole fracture of the patella. We performed a prospective observational study of consecutive cases of inferior pole fracture of the patella that were treated at our institution between January 2018 and June 2019. The patients include three men and one woman, with an average age of 47 years (range: 42-59 years). All patients were treated with the novel rim plating fixation technique for preserving the inferior pole of the patella. During the surgery, a 2.4 mm straight locking compression plate was contoured to adapt to the arc of the lower half of the patella as the rim plate. After reduction of the fracture, the rim plate was fixed to the proximal fragment of the patella through multiple locking screws, against the continuous pull of the patellar tendon. The rim plate encircles and constricts the inferior pole fragments, functioning as a compression and blocking construct. If necessary, an additional anterior tension band or mini locking plate can be used to further prevent anterior displacement of the inferior pole fragments. Under this rigid fixation, motion of the knee and full weight-bearing were encouraged postoperatively. The patients were followed up monthly until 12 months after surgery. The time to achieve 90°pain-free, full range of motion of the knee, and fracture healing, were recorded. Related complications were monitored, including infection, loss of reduction, fixation failure, anterior knee pain, and soft-tissue irritation. The modified Cincinnati knee rating system was used for knee function assessment. The average operative time was 58.8 min (range: 52-63 min). The average blood loss was 59.8 mL (range: 45-71 mL). For all patients, pain-free 90° range of motion was restored in 2-4 weeks, and the full range of motion was restored in 8-11 weeks. All patients achieved bone union in 6-9 weeks with no displacement of the fragments or breakage of the implant. No patient complained of anterior knee pain or soft-tissue irritation. The modified Cincinnati score at 12-month follow up demonstrated excellent outcomes in all four patients. The rim plating technique may be a feasible option for the treatment of the inferior pole fracture of the patella.
Topics: Adult; Bone Plates; Bone Screws; Female; Fracture Fixation, Internal; Fractures, Bone; Humans; Male; Middle Aged; Pain Measurement; Patella; Prospective Studies
PubMed: 33619908
DOI: 10.1111/os.12876 -
Canadian Association of Radiologists... Nov 2016One of the most common knee injuries is ligament tear, which may initially manifest as an osseous injury in radiographs. Radiologists should therefore be able to... (Review)
Review
One of the most common knee injuries is ligament tear, which may initially manifest as an osseous injury in radiographs. Radiologists should therefore be able to recognize ligament tears of the knee as osseous abnormalities in images. This review focuses on the imaging features of knee ligament injuries and their related osseous injuries: anterior cruciate ligament (ACL) tear with Segond fracture; associated marrow contusion; ACL avulsion fracture; posterior cruciate ligament (PCL) tear with osseous avulsion of the ligament including arcuate sign; reverse Segond fracture; PCL avulsion fracture; medial collateral ligament tear with Pellegrini-Stieda disease; lateral collateral ligament tear with avulsion fracture of the fibular head; and patellar ligament injuries with Osgood-Schlatter and Sinding-Larsen-Johansson.
Topics: Femur; Fibula; Humans; Knee Joint; Ligaments, Articular; Magnetic Resonance Imaging; Patella; Radiography; Rupture; Tibia
PubMed: 27499452
DOI: 10.1016/j.carj.2016.02.002 -
Medicine Sep 2017Chondrosarcoma, characterized by the production of cartilage matrix, is a common bone tumor, accounting for 20% to 27% of all malignant bone tumors. It often occurs in...
RATIONALE
Chondrosarcoma, characterized by the production of cartilage matrix, is a common bone tumor, accounting for 20% to 27% of all malignant bone tumors. It often occurs in the cartilage of the pelvis, femur, tibia, and humerus. However, chondrosarcoma of the patella is extremely rare.
PATIENT CONCERNS
The present study describes a case of chondrosarcoma affecting the right patella in a 68-year-old woman. The chief complaints were painful swelling and limitation of motion of the right knee for about half a year. The pain was a kind of dull ache. The skin around the right knee was red and hot. Moreover, she had a claudication gait due to the symptoms.
DIAGNOSES
Irregular lytic lesions with ill-defined margins in the patella were determined through computed tomography and magnetic resonance imaging. The diagnosis of primary grade II chondrosarcoma was finally confirmed on the basis of postoperative pathological examination.
INTERVENTIONS
The patient underwent an open surgery named extensive resection of patellar tumor to remove the tumor tissue completely.
OUTCOMES
The patient was discharged without any complications 1 week after the surgery. At the 3-month follow-up, the patient was completely free from pain during daily activities, and normal range of motion of the right knee was achieved. Her gait was normal. There was no evidence of recurrence.
LESSONS
We believe that an extensive resection is suitable for treating chondrosarcoma to avoid as far as possible local recurrence. An awareness of the potential for chondrosarcoma to present in the patella is crucial for both orthopedic surgeons and radiologists when confronted with similar cases. Besides, as reports of chondrosarcoma of the patella are rare, this study adds a better understanding of this rare condition to the medical literature.
Topics: Aged; Bone Neoplasms; Chondrosarcoma; Female; Humans; Patella
PubMed: 28906396
DOI: 10.1097/MD.0000000000008049 -
Journal of Orthopaedic Surgery and... Jul 2021The objectives of this study were to investigate the anatomic morphology of patellar ridge using computed tomography-based three-dimensional (3D) computer models and to...
BACKGROUND
The objectives of this study were to investigate the anatomic morphology of patellar ridge using computed tomography-based three-dimensional (3D) computer models and to assess the center of the patellar ridge after virtual resections.
METHODS
We selected 80 patients, 40 males (age, 33.2±6.8 years) and 40 females (age, 30.6±7.2 years), who were slightly symptomatic with soft tissue injury of the knee joint. The right or left knees were scanned by computed tomography (CT). The CT data of 160 knees was used to construct 3D computer models by image analysis software (Mimics). Variables such as the angle between the patellar ridge and patellar long axis, the distance between the center of the patellar ridge and the center of patellar cut after virtual resections were measured. We detect differences between the sides and genders with the 3D computer models by Student's t test. Simple linear regression and correlation test was used to correlate the patellar ridge center to the center of the patellar cut.
RESULTS
According to the available data, there were significant gender differences in the length and width of patellar cut after virtual resections even with strict control for the height and weight of the patients. The angle between the patellar ridge and the patellar long axis was 11.24° ± 3.62°. The angle in male patients was 10.17° ± 4.82°, and it was 12.28°± 3.78° in female patients. The morphological difference was statistically significant (P < 0.05). After using the subchondral method to virtually resect the patellae, with reference to the center of the patellar cut, the center of the patellar ridge lies superiorly and medially in 88.75%, inferiorly and medially in 8.75%, laterally and superiorly in 2.5%, and in no case laterally and inferiorly. The intra-observer reliability regarding the dimensional measurements was excellent in this study.
CONCLUSIONS
Advances in 3D computer models had resulted in the availability of preoperative measurement and virtual planning. The anthropometric dimensions of this study could provide general information for guiding surgical management of the patella in total knee arthroplasty (TKA) and were useful in designing patellar implants.
CLINICAL RELEVANCE
The placement of the patellar component during TKA differs from one patella to another. The anatomic morphology information of the patellar ridge is helpful for surgeons to perform patellar resurfacing in TKA.
Topics: Adult; Anatomic Landmarks; Arthroplasty, Replacement, Knee; Computer Simulation; Female; Humans; Imaging, Three-Dimensional; Male; Patella; Sex Factors; Tomography, X-Ray Computed
PubMed: 34229682
DOI: 10.1186/s13018-021-02587-z -
Journal of Anatomy Nov 2017There is a consensus that there is no overt anterior joint capsule in the knee. However, other anterior structures act in lieu of a joint capsule: the quadriceps tendon...
There is a consensus that there is no overt anterior joint capsule in the knee. However, other anterior structures act in lieu of a joint capsule: the quadriceps tendon and patellar retinacular fibres. In the absence of a capsule, the synovium forms the suprapatellar pouch. Other synovial structures, the plicae, are more controversial. They are often described as embryonic remnants with no function, despite surrounding the patella. We aimed to identify plical anatomy and histology on cadaveric dissection and to examine their embryology using the human virtual embryo website. Plicae were identified by two independent observers. Plical histology was examined using a panel of stains: H&E, Ab H&E, EVG and MSB trichrome. Embryonic knees were examined from Carnegie stages 20-23. Each knee had a suprapatellar plica and mediopatellar plica (MPP). The lateropatellar plica (LPP) appeared as a band in 5/10 cadavers, and as a ridge in the remainder. The overall impression, consistent across all specimens, was that the plicae formed a continuous band of synovial tissue around the proximal three-quarters of the patella. The infrapatellar fat pad (IFP) surrounded the remainder. Histologically, the plicae and IFP consisted of three layers (in order): a synovial layer, an undulated collagenous layer, and an adipose or areoloadipose layer. The subsynovial collagenisation is normally associated with the synovio-capsular boundary. Embryologically, plicae were not seen in either knee at any level for any given Carnegie stage. We suggest that plicae, along with the dynamic IFP, provide internal support to the patella mirroring the external support of retinacular fibres. Thus, the plicae complete the tissue complex acting in lieu of an anterior joint capsule. Evidence of plical functionality lends credence to the theory that the plicae are anatomical structures not functionless embryonic remnants.
Topics: Aged; Aged, 80 and over; Cadaver; Female; Humans; Knee Joint; Male; Middle Aged; Patella
PubMed: 28718946
DOI: 10.1111/joa.12662