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Canadian Prosthetics & Orthotics Journal 2023Residual limb discomfort and injury is a common experience for people living with lower limb amputation. Frequently, inadequate load distribution between the prosthetic...
BACKGROUND
Residual limb discomfort and injury is a common experience for people living with lower limb amputation. Frequently, inadequate load distribution between the prosthetic device and the residual limb is the root cause of this issue. To advance our understanding of prosthetic interface fit, tools are needed to evaluate the mechanical interaction at the prosthetic interface, allowing interface designs to be evaluated and optimised.
OBJECTIVE
Present a methodology report designed to facilitate comprehension of the mechanical interaction between the prosthetic interface and the residual limb. As a pilot study, this methodology is used to compare a hands-on and hands-off interface for a single transtibial prosthesis user using secondary Magnetic Resonance Imaging (MRI) data.
METHODOLOGY
MRI data of the residual limb while wearing a prosthetic interface is segmented into a hard tissue and a skin surface model. These models are exported as stereolithography (STL) files. Two methods are used to analyse the interface designs. Firstly, CloudCompare software is used to compute the nearest vertex on the skin surface for every vertex on the compiled internal bony surface for both interface types. Secondly, CloudCompare software is used to compare registered skin surfaces of the residual limb while wearing the hands-on and hands-off interfaces.
FINDINGS
The maximum and minimum nearest distances between the internal bony surface and skin surface were similar between interface types. However, the distribution of nearest distances was different. When comparing the skin surface while wearing both interfaces, where the fit is more compressive can be visualized. For the dataset used in this study, the classic features of a hands-on Patella Tendon Bearing interface and hands-off pressure cast interface could be identified.
CONCLUSION
The methodology presented in this report may give researchers a further tool to better understand how interface designs affect the soft tissues of the residual limb.
PubMed: 38873008
DOI: 10.33137/cpoj.v6i1.42196 -
Orthopaedic Journal of Sports Medicine Jun 2024While the biomechanical properties of the native medial patellofemoral ligament (MPFL) have been well studied, there is no comprehensive summary of the biomechanics of... (Review)
Review
BACKGROUND
While the biomechanical properties of the native medial patellofemoral ligament (MPFL) have been well studied, there is no comprehensive summary of the biomechanics of MPFL reconstruction (MPFLR). An accurate understanding of the kinematic properties and functional behavior of current techniques used in MPFLR is imperative to restoring native biomechanics and improving outcomes.
PURPOSE
To provide a comprehensive review of the biomechanical effects of variations in MPFLR, specifically to determine the effect of graft choice and reconstruction technique.
STUDY DESIGN
Systematic review.
METHODS
A systematic review was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A total of 32 studies met inclusion criteria: (1) using ≥8 human cadaveric specimens, (2) reporting on a component of MPFLR, and (3) having multiple comparison groups.
RESULTS
Gracilis, semitendinosus, and quadriceps grafts demonstrated an ultimate load to failure (N) of 206.2, 102.8, and 190.0 to 205.0 and stiffness (N/mm) of 20.4, 8.5, and 21.4 to 33.6, respectively. Single-bundle and double-bundle techniques produced an ultimate load to failure (N) of 171 and 213 and stiffness (N/mm) of 13.9 and 17.1, respectively. Anchors placed centrally and superomedially in the patella produced the smallest degree of length changes throughout range of motion in contrast to anchors placed more proximally. Sutures, suture anchors, and transosseous tunnels all produced similar ultimate load to failure, stiffness, and elongation data. Femoral tunnel malpositioning resulted in significant increases in contact pressures, patellar translation, tilt, and graft tightening or loosening. Low tension grafts (2 N) most closely restored the patellofemoral contact pressures, translation, and tilt. Graft fixation angles variably and inconsistently altered contact pressures, and patellar translation and tilt.
CONCLUSION
Data demonstrated that placement of the MPFLR femoral tunnel at the Schöttle point is critical to success. Femoral tunnel diameter should be ≥2 mm greater than graft diameter to limit graft advancement and overtensioning. Graft fixation, regardless of graft choice or fixation angle, is optimally performed under minimal tension with patellar fixation at the medial and superomedial patella. However, lower fixation angles may reduce graft strain, and higher fixation angles may exacerbate anisometry and length changes if femoral tunnel placement is nonanatomic.
PubMed: 38855071
DOI: 10.1177/23259671241241537 -
Cureus May 2024The patella, or kneecap, is a sesamoid bone situated deep to the fascia latae and the tendinous fibers of the rectus femoris. The medial and lateral facets of the...
BACKGROUND
The patella, or kneecap, is a sesamoid bone situated deep to the fascia latae and the tendinous fibers of the rectus femoris. The medial and lateral facets of the patella articulate with the medial and lateral condyles of the femur, respectively, to form the patellofemoral component of the knee joint. When joint cartilage is destroyed due to osteoarthritis, inflammatory arthritis, post-traumatic degenerative joint disease, or osteonecrosis/joint collapse with cartilage loss, a surgical treatment called knee arthroplasty, or total knee arthroplasty (TKA), is used to rebuild the knee joint.
OBJECTIVES
The purpose of our study is to provide a detailed morphometric analysis of the human patella.
METHODS
A total of 168 patellae (86 left, 82 right) were examined. Eleven parameters were determined to evaluate patella morphometry, and the bones were also evaluated with the Wiberg classification.
RESULT
Type I patella was observed in 13 samples (7.74%); 109 (64.88%) and 46 (27.38%) were Type II and Type III, respectively. In the statistical analysis, significant differences were found between the right and left patellae in terms of patellar thickness, vertical ridge length, and Wiberg angle (p<0.05). There were also significant differences between the Wiberg types and the medial articular width and lateral articular width (p<0.05).
CONCLUSION
In order to avoid potential difficulties during knee surgery, it is crucial to understand the typical morphological and morphometric properties of the patella. We believe that this study will be useful to surgeons who perform surgical approaches to the knee and to clinicians who evaluate the diseases of the region.
PubMed: 38854214
DOI: 10.7759/cureus.59852 -
Orthopaedic Journal of Sports Medicine Jun 2024Patellar instability is frequently encountered in patients with Ehlers-Danlos syndrome (EDS). The clinical outcomes of isolated medial patellofemoral ligament...
BACKGROUND
Patellar instability is frequently encountered in patients with Ehlers-Danlos syndrome (EDS). The clinical outcomes of isolated medial patellofemoral ligament reconstruction (MPFLR) for patellar instability in patients with EDS are unknown.
PURPOSE
To evaluate midterm clinical outcomes of isolated MPFLR for patellar instability in patients with EDS and factors affecting these outcomes.
STUDY DESIGN
Case series; Level of evidence, 4.
METHODS
In a retrospective study, 31 patients (n = 47 knees) with EDS and patellar instability who underwent isolated MPFLR for recurrent patellar instability between 2008 and 2017 and had a minimum 2-year follow-up were identified. Preoperative radiographic images were measured for anatomic risk factors. Clinical outcomes-including postoperative complications-were evaluated. Factors associated with MPFLR failure were identified. Postoperative patient-reported outcomes (PROs)-including the pediatric version of the International Knee Documentation Committee, the Kujala score, the Hospital for Special Surgery Pediatric Functional Activity Brief Scale, the Banff Patellofemoral Instability Instrument 2.0, and the Knee injury and Osteoarthritis Outcome Score-were collected, and factors affecting PRO scores were analyzed.
RESULTS
The mean age of the cohort was 14.9 ± 2 years. At a mean follow-up of 7.2 years, 18 of 47 (38.3%) knees required reoperations, of which 9 of 47 (19.1%) knees required revision stabilization for recurrent patellar instability. Also, 7 of 31 knees (22.6%) with autografts failed compared with 2 of 16 (12.5%) with allografts ( = .69). For autografts, 6 of 17 (35.3%) failures occurred with gracilis, but 0 of 13 (0%) occurred with semitendinosus ( = .02). Compared with patients without failures, patients with failed primary MPFLR were significantly younger ( = .0005) and were able to touch the palm to the floor with their knees extended ( = .03). For radiographic parameters, the patellar height and tilt were significantly higher in the failure group. The postoperative PROs were suboptimal at a mean follow-up of 5.2 years. All but 1 patient were satisfied with the final outcome.
CONCLUSION
At the midterm follow-up, 38.3% of patients with EDS required further surgery after isolated MPFLR for patellar instability; half of these revisions (19.1%) were to address recurrent instability. Recurrent instability after isolated MPFLR was more likely in younger patients and those who could touch the palm to the floor with their knees extended. Postoperative PROs were inferior; nonetheless, patient satisfaction was high.
PubMed: 38845609
DOI: 10.1177/23259671241241096 -
Arthroscopy : the Journal of... Jun 2024To compare the sagittal position of the tibial tubercle in relation the trochlea groove in patients with and without trochlear dysplasia (TD).
PURPOSE
To compare the sagittal position of the tibial tubercle in relation the trochlea groove in patients with and without trochlear dysplasia (TD).
METHODS
All patients between January 2017 and December 2020 with high-grade TD (Dejour type B, C and D) who underwent patellar stabilizing surgery for patellar instability at a single institution were included in the current study. Patients without preoperative magnetic resonance imaging (MRI), any prior osteotomy on the affected lower extremity or cruciate ligament insufficiency were excluded. Patients who underwent knee arthroscopy for meniscal repair/debridement without any signs of TD or any of the above-mentioned criteria served as control group. Preoperative magnetic-resonance imaging (MRI) was retrospectively assessed to compare common patellofemoral anatomic parameters including patellar angle, patellar tilt, patella morphology according to Wiberg, Caton-Deschamps index (CDI), PF index, trochlear sulcus angle, sulcus depth, lateral inclination angle of the trochlea, tibiofemoral rotation, TTTG and sTTTG distance, between both groups. The sTTTG is measured as the distance between the nadir point of the cartilaginous trochlear groove and the most anterior point of the tibial tubercle on an axial MRI. Independent predictors for the sTTTG were assessed for patients with TD.
RESULTS
Patients with high-grade TD (n=82) showed an increased patellar tilt, CDI, trochlear sulcus angle, lateral tibiofemoral rotation angle, TTTG and sTTTG (9.16 ± 4.47 mm vs. 2.66 ± 4.21 mm) compared to the control group (n=83) (p<0.001). Patellar angle, PF index, sulcus depth and lateral inclination angle of the trochlear were significantly decreased in the TD group (p<0.001). The sTTTG was similar in all TD groups (n.s.). Among patients with TD, both tibiofemoral rotation and patellar height were independent predictors of the sTTTG (p<0.05).
CONCLUSION
Patients with high-grade TD show not only abnormal values in common patellofemoral instability risk factors, but also a significantly increased sTTTG compared to patients without TD.
LEVEL OF EVIDENCE
Retrospective case comparative study, III.
PubMed: 38844015
DOI: 10.1016/j.arthro.2024.05.023 -
Arthroscopy Techniques May 2024Patellar tendinopathy is an overuse injury of the patella tendon common in jumping sports or activities. Degeneration of the patellar tendon fibers causes microtears in...
Patellar tendinopathy is an overuse injury of the patella tendon common in jumping sports or activities. Degeneration of the patellar tendon fibers causes microtears in the tendon, leading to partial patellar tendon tears. If nonoperative treatment fails and the tears are mild, a debridement of the detached tissue with a patella tendon repair can help to reduce pain, promote healing, and improve function. However, if more than 50% of the patella tendon attachment to the inferior pole of the patella is detached, a debridement with a patellar tendon reconstruction is indicated to restore the strength of the patellar tendon. This reconstruction technique uses gracilis and semitendinosus autografts to surround and reconstruct the patellar tendon. Tunnels are drilled horizontally at the tibial tubercle and through the midpoint of the patella for graft passage. This technique can help to improve patient outcomes and reduce some of the risk of failure associated with performing only the debridement when significant partial patellar tendon tearing is present.
PubMed: 38835451
DOI: 10.1016/j.eats.2024.102931 -
Journal of Children's Orthopaedics Jun 2024The purpose of this study is to assess clinical and functional outcomes in separate cohorts of operatively and nonoperatively managed pediatric patella fractures.
PURPOSE
The purpose of this study is to assess clinical and functional outcomes in separate cohorts of operatively and nonoperatively managed pediatric patella fractures.
METHODS
A retrospective review was completed for patients aged 5-19 years treated for a unilateral patella fracture at a single pediatric level-1 trauma center. Patients were excluded for osteochondral fracture associated with patellar dislocation, polytrauma presentation with additional fractures, or <3 months of clinical follow-up. Functional outcomes were assessed via the Pediatric International Knee Documentation Committee form and the Marx Knee Activity Scale.
RESULTS
A total of 53 patients met inclusion criteria; 30 patients were treated operatively and 23 patients were treated nonoperatively. Patients with patellar sleeve/pole fractures were significantly younger by 5.2 years (p < 0.01) and presented with greater variability in mechanism of injury (p < 0.01). The nonoperative cohort achieved bony healing and returned to sports at a median (interquartile range) of 1.7 (1.2-2.3) months and 2.8 (2.3-3.3) months, respectively, post-injury. The operative group achieved bony healing and returned to sports at 2.8 (2.1-3.5) months and 5.9 (4.0-7.1) months, respectively, following surgery. Median (interquartile range) Pediatric International Knee Documentation Committee and Marx scores were 98 (89-100) and 14 (10-16), respectively, for the nonoperative group, and 92 (84-99) and 13 (12-16), respectively, for the operative group. No significant differences in patient-reported outcomes were observed between fracture patterns or treatment cohorts.
CONCLUSION
Pediatric and adolescent patients sustaining patella fractures reported long-term functional outcomes comparable to normative values, across multiple fracture patterns and with appropriate operative and nonoperative treatment. Fractures requiring surgery were expectedly associated with slower healing and return to sport timelines.
LEVEL OF EVIDENCE
Therapeutic Level III.
PubMed: 38831855
DOI: 10.1177/18632521241232301 -
Bone & Joint Open Jun 2024During total knee replacement (TKR), surgeons can choose whether or not to resurface the patella, with advantages and disadvantages of each approach. Recently, the...
The clinical and cost-effectiveness of elective primary total knee replacement with PAtellar Resurfacing compared to selective patellar resurfacing: a pragmatic multicentre randomized controlled Trial (PART).
AIMS
During total knee replacement (TKR), surgeons can choose whether or not to resurface the patella, with advantages and disadvantages of each approach. Recently, the National Institute for Health and Care Excellence (NICE) recommended always resurfacing the patella, rather than never doing so. NICE found insufficient evidence on selective resurfacing (surgeon's decision based on intraoperative findings and symptoms) to make recommendations. If effective, selective resurfacing could result in optimal individualized patient care. This protocol describes a randomized controlled trial to evaluate the clinical and cost-effectiveness of primary TKR with always patellar resurfacing compared to selective patellar resurfacing.
METHODS
The PAtellar Resurfacing Trial (PART) is a patient- and assessor-blinded multicentre, pragmatic parallel two-arm randomized superiority trial of adults undergoing elective primary TKR for primary osteoarthritis at NHS hospitals in England, with an embedded internal pilot phase (ISRCTN 33276681). Participants will be randomly allocated intraoperatively on a 1:1 basis (stratified by centre and implant type (cruciate-retaining vs cruciate-sacrificing)) to always resurface or selectively resurface the patella, once the surgeon has confirmed sufficient patellar thickness for resurfacing and that constrained implants are not required. The primary analysis will compare the Oxford Knee Score (OKS) one year after surgery. Secondary outcomes include patient-reported outcome measures at three months, six months, and one year (Knee injury and Osteoarthritis Outcome Score, OKS, EuroQol five-dimension five-level questionnaire, patient satisfaction, postoperative complications, need for further surgery, resource use, and costs). Cost-effectiveness will be measured for the lifetime of the patient. Overall, 530 patients will be recruited to obtain 90% power to detect a four-point difference in OKS between the groups one year after surgery, assuming up to 40% resurfacing in the selective group.
CONCLUSION
The trial findings will provide evidence about the clinical and cost-effectiveness of always patellar resurfacing compared to selective patellar resurfacing. This will inform future NICE guidelines on primary TKR and the role of selective patellar resurfacing.
PubMed: 38828864
DOI: 10.1302/2633-1462.56.BJO-2023-0154 -
Clinics in Orthopedic Surgery Jun 2024Treatment of comminuted patellar fractures accompanied by coronal split articular and inferior pole fragments is a challenge. To treat this difficult fracture, we...
Articular Fragment Detachment and Separate Fixation for the Treatment of Comminuted Patellar Fractures with Coronal Split Articular Fragments: Articular Detachment Technique.
BACKGROUND
Treatment of comminuted patellar fractures accompanied by coronal split articular and inferior pole fragments is a challenge. To treat this difficult fracture, we perform articular fragment detachment and separate fixation for coronal split articular and inferior pole fragments. We aimed to evaluate the radiological and clinical outcomes of our technique in comminuted patellar fractures at least 1 year after surgery.
METHODS
Between January 2019 and June 2022, 15 patients diagnosed with comminuted patellar fractures accompanied by coronal split articular and inferior pole fragments based on preoperative computed tomography underwent surgery using the articular detachment technique. The key point of this technique was anatomical reduction and subchondral fixation of the coronal split articular fragment to the superior main fragment after complete detachment of the coronal split fragment from the inferior pole. The remaining inferior pole was fixed using a separate construct. Postoperative articular gap, articular step-off, and complications, including resorption, reduction loss, and avascular necrosis of fixed articular fragments, were evaluated as radiological outcomes. Range of motion and the Lysholm scores were used to evaluate clinical outcomes.
RESULTS
Among the 15 patients, the coronal split articular fragments were fixed using Kirschner wires in 13 patients and headless screws in 2 patients. The inferior poles were fixed using separate vertical wiring in 13 patients and tension-band wiring in 2 patients. A postoperative articular gap was noted in 7 patients, with an average articular gap of 1.0 mm (range, 0.7-1.6 mm). No articular step-off was observed. Bone union and normal range of motion were achieved in all patients. On the 1-year postoperative lateral radiograph, resorption of the articular fracture site was seen in 5 patients. There was no loss of reduction or avascular necrosis of the coronal split articular fragments. The average postoperative Lysholm score at 1 year was 89.3 ± 4.1 (range, 82-95).
CONCLUSIONS
The technique would be a reliable and safe option for the surgical treatment of comminuted patellar fractures accompanied by coronal split articular and inferior pole fragments in terms of anatomical reduction and stable fixation of articular fragments without risk of avascular necrosis.
Topics: Humans; Fractures, Comminuted; Patella; Male; Female; Adult; Fracture Fixation, Internal; Middle Aged; Bone Wires; Retrospective Studies; Tomography, X-Ray Computed; Young Adult; Bone Screws; Fractures, Bone
PubMed: 38827765
DOI: 10.4055/cios23302 -
BioRxiv : the Preprint Server For... May 2024Neofunctionalization of duplicated gene copies is thought to be an important process underlying the origin of evolutionary novelty and provides an elegant mechanism for...
Neofunctionalization of duplicated gene copies is thought to be an important process underlying the origin of evolutionary novelty and provides an elegant mechanism for the origin of new phenotypic traits. One putative case where a new gene copy has been linked to a novel morphological trait is the origin of the arachnid patella, a taxonomically restricted leg segment. In spiders, the origin of this segment has been linked to the origin of the paralog , suggesting that a new gene facilitated the expression of a new trait. However, various arachnid groups that possess patellae do not have a copy of , disfavoring the direct link between gene origin and trait origin. We investigated the developmental genetic basis for patellar patterning in the harvestman , which lacks . Here, we show that the harvestman patella is established by a novel expression domain of the transcription factor . Leveraging this definition of patellar identity, we surveyed targeted groups across chelicerate phylogeny to assess when this trait evolved. We show that a patellar homolog is present in Pycnogonida (sea spiders) and various arachnid orders, suggesting a single origin of the patella in the ancestor of Chelicerata. A potential loss of the patella is observed in Ixodida. Our results suggest that the modification of an ancient gene, rather than the neofunctionalization of a new gene copy, underlies the origin of the patella. Broadly, this work underscores the value of comparative data and broad taxonomic sampling when testing hypotheses in evolutionary developmental biology.
PubMed: 38826321
DOI: 10.1101/2024.05.16.594547