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The Iowa Orthopaedic Journal 2017This study aims to provide biomechanical data on the effect of patella height in the setting of medial patellofemoral ligament (MPFL) reconstruction using finite element...
BACKGROUND
This study aims to provide biomechanical data on the effect of patella height in the setting of medial patellofemoral ligament (MPFL) reconstruction using finite element analysis. The study will also examine patellofemoral joint biomechanics using variable femoral insertion sites for MPFL reconstruction.
METHODS
A previously validated finite element knee model was modified to study patella alta and baja by translating the patella a given distance to achieve each patella height ratio. Additionally, the models were modified to study various femoral insertion sites of the MPFL (anatomic, anterior, proximal, and distal) for each patella height model, resulting in 32 unique scenarios available for investigation.
RESULTS
In the setting of patella alta, the patellofemoral contact area decreased, resulting in a subsequent increase in maximum patellofemoral contact pressures as compared to the scenarios with normal patellar height. Additionally, patella alta resulted in decreased lateral restraining forces in the native knee scenario as well as following MPFL reconstruction. Changing femoral insertion sites had a variable effect on patellofemoral contact pressures; however, distal and anterior femoral tunnel malpositioning in the setting of patella alta resulted in grossly elevated maximum patellofemoral contact pressures as compared to other scenarios.
CONCLUSIONS
Patella alta after MPFL reconstruction results in decreased lateral restraining forces and patellofemoral contact area and increased maximum patellofemoral contact pressures. When the femoral MPFL tunnel is malpositioned anteriorly or distally on the femur, the maximum patellofemoral contact pressures increase with severity of patella alta.
CLINICAL RELEVANCE
When evaluating patients with patellofemoral instability, it is important to recognize patella alta as a potential aggravating factor. Failure to address patella alta in the setting of MPFL femoral tunnel malposition may result in even further increases in patellofemoral contact pressures, making it essential to optimize intraoperative techniques to confirm anatomic MPFL femoral tunnel positioning.
Topics: Biomechanical Phenomena; Finite Element Analysis; Humans; Joint Instability; Models, Anatomic; Patella; Patellofemoral Joint
PubMed: 28852343
DOI: No ID Found -
Knee Surgery, Sports Traumatology,... Jun 2015To conduct a systematic review and network meta-analysis of randomized controlled trials (RCTs) with the aim of comparing relevant clinical outcomes between patellar... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
To conduct a systematic review and network meta-analysis of randomized controlled trials (RCTs) with the aim of comparing relevant clinical outcomes between patellar denervation, resurfacing and non-resurfacing.
METHODS
A database search was performed using PubMed and Scopus search engines. RCTs or quasi-experimental designs comparing clinical outcomes between treatments by a search of articles dated from inception to October 23, 2012. Unstandardized mean difference (UMD) and random effects methods were applied for pooling continuous and dichotomous outcomes, respectively. A longitudinal mixed regression model was used for network meta-analysis to indirectly compare treatment effects.
RESULTS
Eighteen of 315 studies identified were eligible. Compared with patellar non-resurfacing, patellar denervation had a UMD that displayed a significant improvement in symptoms with values in pain visual analog score (VAS) and Knee Society Score (KSS) of -0.6 [95% confidence interval (CI) -1.13, -0.25] and 2.55 (95% CI 0.43, 4.68), respectively. The UMD in VAS, KSS, and Knee Function Score (KFS) in patellar resurfacing showed no significant improvement in symptoms when compared to non-resurfacing. Patients who underwent surgery with patellar resurfacing had a lower reoperation rates with pooled relative risks (RRs) of 0.69 (95% CI 0.50, 0.94) when compared to non-resurfacing. The network meta-analysis suggested a benefit of borderline significance for patellar denervation with a pooled RR of 0.63 (95% CI 0.38, 1.03), showing that there is a lower chance of anterior knee pain when compared to non-resurfacing. Patellar resurfacing also displays a significantly lower chance of reoperation with a pooled RR of 0.68 (95% CI 0.50, 0.92) when compared to non-resurfacing. Multiple active treatment comparisons indicated that patellar denervation resulted in greater improvement in KFS than patellar resurfacing.
CONCLUSION
This review suggests that either patellar denervation or patellar resurfacing may be selected for the management of the patellofemoral component in total knee replacement. Patellar denervation may help improve postoperative knee function, but does not improve pain when compared to patellar resurfacing.
Topics: Arthroplasty, Replacement, Knee; Denervation; Humans; Knee Joint; Osteoarthritis, Knee; Patella; Postoperative Complications; Reoperation; Visual Analog Scale
PubMed: 25218579
DOI: 10.1007/s00167-014-3311-z -
International Orthopaedics Nov 2015The presented overview shows that the first efforts to address patellar fractures by operative treatment, although sporadic, emerged in the pre-antiseptic era.... (Review)
Review
The presented overview shows that the first efforts to address patellar fractures by operative treatment, although sporadic, emerged in the pre-antiseptic era. Introduction of Lister's antiseptic method in Great Britain, Germany and the USA in 1877-1882 contributed to a new, progressive trend in the treatment of fractures of the patella as well as of other bones. The authors, using Lister's antiseptic method, evaluated three basic aspects in their operations, namely healing of the surgical wound without infective complications, achievement of bony union and a good functional outcome, i.e. restoring the range of motion in the knee, even if limited in most cases. The majority of them used a longitudinal incision and fixation by a silver wire.
Topics: Europe; Fracture Fixation, Internal; Fractures, Bone; History, 19th Century; Humans; Patella; United States
PubMed: 25913262
DOI: 10.1007/s00264-015-2768-9 -
Journal of Orthopaedic Surgery and... Jul 2017The shape of the patella has been considered to be a predisposing factor resulting in patellar instability, but the effects of abnormal patella position during its...
BACKGROUND
The shape of the patella has been considered to be a predisposing factor resulting in patellar instability, but the effects of abnormal patella position during its development are unclear. The present study evaluated patellar morphological changes after patella instability and evaluated the influence of patellar instability on the patella shape.
METHODS
Twenty rabbits that were 2 months old were included in the study. The left knee of each rabbit, defined as the experimental group (N = 20 knees/group), underwent a medial soft tissue restraint release. The right knee of each rabbit, defined as the control group (N = 20 knees/group), did not undergo any surgical procedures. A CT scan was performed on each knee before surgery and 6 months post-surgery to measure the transverse diameter, thickness, Wiberg index, and Wiberg angle for analysis of the patellar morphological changes. Cross-specimen examination was conducted to evaluate the differences between the experimental group and the control group.
RESULTS
The four indices remained the same between the two groups before surgery. However, 6 months after surgery, the mean transverse diameter of the patellae in the experimental group was significantly longer than that in the control group (P < 0.001), while the mean thickness in the experimental group was not significantly greater than that in the control group (P = 0.314), resulting in a flattened shape. The Wiberg indices were not significantly different between the two groups. However, the mean Wiberg angle was higher in the experimental group than in the control group (P < 0.001), which resulted in a flattened articular surface of the patella.
CONCLUSION
The sectional shape and articular surface of the patella became more flattened after patella instability in this study, which indicates that patella dysplasia could be caused by patella instability. Clinically, early intervention for adolescent patients with patella instability is important.
Topics: Animals; Joint Instability; Patella; Patellofemoral Joint; Rabbits
PubMed: 28693590
DOI: 10.1186/s13018-017-0615-y -
Joint Bone Spine Oct 2021
Topics: Humans; Patella
PubMed: 33992791
DOI: 10.1016/j.jbspin.2021.105211 -
Prague Medical Report 2021A 49-year-old female fell from standing. Her right knee extended into the air. She had acute right knee pain preventing weight-bearing. Her knee was most comfortable...
A 49-year-old female fell from standing. Her right knee extended into the air. She had acute right knee pain preventing weight-bearing. Her knee was most comfortable fully-extended. She could not flex it due to pain, nor extend it against resistance. Tenderness and a horizontal defect were noted over the anterior knee. Bedside ultrasound demonstrated a horizontally-fractured patella (confirmed on X-ray) with intact femoral and patellar tendons. She was put in a knee immobilizer and underwent surgery, with return to full function and activities. Ultrasound can identify patella fractures and help with early evaluation, management, and specialty referral, as well as ordering more-focused imaging. In one study, POCUS (point-of-care ultrasound) for patella fracture had 95% sensitivity, 63% specificity, 86% positive predictive value, and 83% negative predictive value. The dynamic nature of ultrasound allows a ruptured patella (87% sensitivity) or quadriceps tendon (100% sensitivity) to be excluded with high certainty.
Topics: Humans; Middle Aged; Patella; Point-of-Care Systems
PubMed: 34924109
DOI: 10.14712/23362936.2021.29 -
Annals of the Royal College of Surgeons... Jun 2022We present a rare, previously undescribed case of a superior patella sleeve fracture in a skeletally immature adolescent male, just 1 month following surgery for an...
We present a rare, previously undescribed case of a superior patella sleeve fracture in a skeletally immature adolescent male, just 1 month following surgery for an ipsilateral traumatic inferior pole patella fracture. This was initially missed resulting in a delay to surgery. We recommend a high index of suspicion is key in these patients who re-present following subsequent trauma and alternative X-ray views such as a flexed lateral can be extremely beneficial.
Topics: Adolescent; Fracture Fixation, Internal; Fractures, Bone; Humans; Knee Injuries; Male; Patella; Radiography; Range of Motion, Articular
PubMed: 35174716
DOI: 10.1308/rcsann.2021.0286 -
BMC Musculoskeletal Disorders Jan 2022As several studies have detected correlations between patellar and femoral trochlear development, this raises the question of whether patellar shape is associated with...
BACKGROUND
As several studies have detected correlations between patellar and femoral trochlear development, this raises the question of whether patellar shape is associated with trochlear developmental outcomes.
METHODS
Patellar shape and femoral trochlear morphology were retrospectively analyzed in 183 subjects, of whom 61 each were classified as having Wiberg type I, II, and III patellae (groups A, B, and C, respectively). The sulcus angle (SA), lateral trochlea inclination angle (LTA), medial trochlear inclination angle (MTA), lateral facet length (LFL), medial facet length (MFL), lateral trochlear height (LTH), medial trochlear height (MTH), trochlea sulcus height (TH), and lateral-medial trochlear facet distance (TD) were analyzed as a means of evaluating trochlear morphology. Trochlear depth, trochlear condyle asymmetry, and trochlear facet asymmetry were additionally calculated, and differences in trochlear morphology and correlations between trochlear morphology and patellar shape were evaluated.
RESULTS
The femoral trochlear parameters of patients in group A differed significantly from those of patients in groups B and C. No significant differences between groups B and C were evident. Patellar shape was positively correlated with LTA, MTA, MFL, trochlear condyle asymmetry, and trochlear facet asymmetry, and was negatively correlated with SA.
CONCLUSIONS
These data indicated that patellar shape and trochlear morphology are related to one another,which suggest normalized patella morphology surgery and trochlear surgery are better choices for patients with patella instability.
TRIAL REGISTRATION
Retrospectively registered.
Topics: Femur; Humans; Joint Instability; Magnetic Resonance Imaging; Patella; Patellofemoral Joint
PubMed: 35039027
DOI: 10.1186/s12891-022-05000-w -
Clinical Orthopaedics and Related... Oct 2018
Review
Topics: Arthroscopy; Cartilage Diseases; Cartilage, Articular; Chondromalacia Patellae; Hip Joint; Humans; Knee Joint; Observer Variation; Patella; Predictive Value of Tests; Prognosis; Reproducibility of Results; Severity of Illness Index; Shoulder Joint; Terminology as Topic
PubMed: 29533246
DOI: 10.1007/s11999.0000000000000255 -
Veterinary and Comparative Orthopaedics... Mar 2020The aim of this study was to assess computed tomography (CT) images of cadaveric feline stifles and record the relationship between the patella and femoral trochlea...
OBJECTIVE
The aim of this study was to assess computed tomography (CT) images of cadaveric feline stifles and record the relationship between the patella and femoral trochlea in normal stifles; then to investigate the effect of block recession trochleoplasty (BRT) with and without partial parasagittal patellectomy (PPP) on patellofemoral contact, depth of patellar recession and size of trochlea and patella.
MATERIALS AND METHODS
The sample population included six cat cadavers (12 stifles). Preoperative CT scans with stifles in three positions: extended (155-165°), neutral (85-95°) and flexed (35-45°). Lateral stifle arthrotomy was followed by BRT. CT scans were taken as above. PPP was performed so the width of the patella was 1 mm narrower than the BRT. CT scans were repeated and CT measurements were taken.
RESULTS
The area of contact between the patella and femoral trochlea was significantly reduced after BRT and then significantly increased after PPP. The depth of patellar recession was unchanged after BRT, but then was significantly higher after PPP. The patella was wider than the trochlea preoperatively and post-BRT and narrower post-PPP. Reduction in bone volume following PPP (mean: 20%) was 50% the reduction in patella width (mean: 40%).
CONCLUSION
Block recession trochleoplasty did not improve patellar recession and decreased patellofemoral contact area. Following BRT, the patella rides the trochlear ridges and loses contact with the trochlear sulcus. Block recession trochleoplasty alone should not be performed in cats. Instead, BRT should be combined with PPP.
Topics: Animals; Biomechanical Phenomena; Cadaver; Cats; Femur; Patella; Patellar Dislocation; Stifle; Tomography, X-Ray Computed
PubMed: 31978936
DOI: 10.1055/s-0039-3400313