Reliability of patellotrochlear index in patellar height assessment on MRI—correction for variation due to change in knee flexion

2018 ◽  
Vol 48 (3) ◽  
pp. 387-393 ◽  
Author(s):  
M. Ahmad ◽  
S. Janardhan ◽  
S. Amerasekera ◽  
P. Nightingale ◽  
T. Ashraf ◽  
...  
Keyword(s):  
Knee Flexion ◽  
Patellar Height ◽  
Patellotrochlear Index

scholarly journals Comparison of five patellar height measurement methods in 90° knee flexion

2011 ◽  
Vol 35 (12) ◽  
pp. 1791-1797 ◽  
Author(s):  
Konstantinos Anagnostakos ◽  
Olaf Lorbach ◽  
Sarah Reiter ◽  
Dieter Kohn
Keyword(s):  
Knee Flexion ◽  
Measurement Methods ◽  
Patellar Height ◽  
Height Measurement

scholarly journals Anatomic Magnetic Resonance Imaging Measurements in First-Time Patellar Dislocators by Sex and Age

2019 ◽  
Vol 54 (8) ◽  
pp. 901-905
Author(s):  
Nathan L. Grimm ◽  
Benjamin M. Wooster ◽  
David M. Tainter ◽  
Beau J. Kildow ◽  
Jaewhan Kim ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Intraclass Correlation ◽  
Case Series ◽  
Patellar Height ◽  
Resonance Imaging ◽  
Sulcus Angle ◽  
Magnetic Resonance Imaging Analysis ◽  
First Time ◽  
Patellotrochlear Index

Context Anatomic differences of the knee in first-time patellar dislocators have not been clearly elucidated. Objective To compare structural differences of the knee in those who have sustained an acute first-time patellar dislocation resulting in a medial patellofemoral ligament (MPFL) tear by sex and age (≤17 years old, ≥18 years old). Design Case series. Setting Retrospective magnetic resonance imaging analysis. Patients or Other Participants Thirty-five acute first-time patellar dislocators with an associated MPFL tear. Main Outcome Measure(s) Patellar height using 3 methods, patellar alignment using congruency angles, and trochlear morphology using the sulcus angle. We compared the means of these variables by sex and age. The intraclass correlation coefficient was then calculated to assess the agreement of the independent reviewers. Results A total of 21 left and 14 right knees were analyzed. The MPFL tear location did not differ by sex (P = .34) or age (P = .43). Patellar height did not differ as measured by the Caton-Deschamps ratio (P = .29 for sex, P = .49 for age), Insall-Salvati index (P = .15 for sex, P = .33 for age), or patellotrochlear index (P = .67 for sex, P = .49 for age). The congruence angle (P = .81 for sex, P = .06 for age) and trochlear morphology as measured by the sulcus angle (P = .64 for sex, P = .45 for age) were similar between groups. Conclusions Patellar height and trochlear morphology did not differ by sex or age among patients whose first-time patellar dislocations resulted in an MPFL tear. In addition, the location of the tear did not appear to vary by sex or age.

scholarly journals Significant reduction of patellar height affected lower clinical outcomes and knee flexion over five-year follow-up after total knee arthroplasty

2021 ◽  
Vol 2 (12) ◽  
pp. 1075-1081
Author(s):  
Ashish Suthar ◽  
Kiminori Yukata ◽  
Yoshikazu Azuma ◽  
Yutaka Suetomi ◽  
Kazuhiro Yamazaki ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Measurement Error ◽  
Clinical Outcomes ◽  
Knee Flexion ◽  
Patellar Height ◽  
Fixed Bearing ◽  
Patella Baja ◽  
Total Knee ◽  
The Relationship

Aims This study aimed to investigate the relationship between changes in patellar height and clinical outcomes at a mean follow-up of 7.7 years (5 to 10) after fixed-bearing posterior-stabilized total knee arthroplasty (PS-TKA). Methods We retrospectively evaluated knee radiographs of 165 knees, which underwent fixed-bearing PS-TKA with patella resurfacing. The incidence of patella baja and changes in patellar height over a minimum of five years of follow-up were determined using Insall-Salvati ratio (ISR) measurement. We examined whether patella baja (ISR < 0.8) at final follow-up affected clinical outcomes, knee joint range of motion (ROM), and Knee Society Score (KSS). We also assessed inter- and intrarater reliability of ISR measurements and focused on the relationship between patellar height reduction beyond measurement error and clinical outcomes. Results The ISR gradually decreased over five years after TKA, and finally 33 patients (20.0%) had patella baja. Patella baja at the final follow-up was not related to passive knee ROM or KSS. Interestingly, when we divided into two groups - patella baja and patella normal-alta (ISR ≥ 0.8) - the patella baja group already had a lower patellar height before surgery, compared with the patella normal-alta group. The ISR measurement error in this study was 0.17. Both passive knee flexion and KSS were significantly decreased in the group with a decrease in ISR of ≥ 0.17 at final follow-up. Conclusion Patellar height gradually decreased over five years of follow-up after TKA. The reduction in patellar height beyond measurement error following TKA was associated with lower clinical outcomes. Cite this article: Bone Jt Open 2021;2(12):1075–1081.

A PHOTOELASTIC MODEL OF THE PATELLOFEMORAL JOINT TO STUDY PATELLAR HEIGHT

2020 ◽  
Vol 20 (07) ◽  
pp. 2050049
Author(s):  
GUSTAVO APARICIO
Keyword(s):  
Knee Flexion ◽  
Patellofemoral Joint ◽  
Contact Point ◽  
Reaction Force ◽  
Patellar Height ◽  
Extensor Mechanism ◽  
Moment Arm ◽  
Moment Arms ◽  
Contact Points ◽  
Ligamentum Patellae

Background: Patellar height has been related to anterior knee pain and Osgood–Schlatter disease. To study the influence of patellar height on knee biomechanics, a bidimensional photoelastic prototype of the patellofemoral joint was developed. Methods: Nine tests were performed at different knee flexion angles and patellar heights. A free body diagram was constructed for each test. The following parameters were calculated: lengths (patella, patella thickness and ligamentum patellae); patellar height index; angles (knee flexion, patellar flexion, quadriceps and ligamentum patellae force and reaction force at the ankle); moment arms (extensor, quadriceps and ligamentum patellae in relation to both the tibiofemoral and patellofemoral contact points), effective moment arm and forces around the extensor mechanism relative to the applied force. Results: Femoropatellar and femorotibial reaction forces were greater with increased knee flexion and a fixed patellar height. With fixed knee flexion and different patellar heights, these forces were greater if the patella was elevated. A decrease in the angle between the tibial axis and ligamentum patellae was observed when patellar height increased. Patellar flexion angle increased when patellar height increased. This was accompanied by an increase in the angle of action of the quadriceps force. Extensor moment arm decreased with increased patellar height when knee flexion and the tibiofemoral contact point were fixed. Conclusion: A new application of photoelasticity is presented. The preliminary findings obtained confirm the influence of patellar height on patellar biomechanics, and specifically on forces around the extensor mechanism of the knee.

Cardiovascular and Metabolic Responses to Electrical Stimulation-Induced Leg Exercise in Spinal Cord Injury

1997 ◽  
Vol 36 (04/05) ◽  
pp. 372-375 ◽  
Author(s):  
J. R. Sutton ◽  
A. J. Thomas ◽  
G. M. Davis
Keyword(s):  
Spinal Cord ◽  
Heart Rate ◽  
Spinal Cord Injury ◽  
Cardiac Output ◽  
Electrical Stimulation ◽  
Knee Flexion ◽  
Flexion Extension ◽  
Cord Injury ◽  
Leg Exercise ◽  
Leg Muscle

Abstract:Electrical stimulation-induced leg muscle contractions provide a useful model for examining the role of leg muscle neural afferents during low-intensity exercise in persons with spinal cord-injury and their able-bodied cohorts. Eight persons with paraplegia (SCI) and 8 non-disabled subjects (CONTROL) performed passive knee flexion/extension (PAS), electrical stimulation-induced knee flexion/extension (ES) and voluntary knee flexion/extension (VOL) on an isokinetic dynamometer. In CONTROLS, exercise heart rate was significantly increased during ES (94 ± 6 bpm) and VOL (85 ± 4 bpm) over PAS (69 ± 4 bpm), but no changes were observed in SCI individuals. Stroke volume was significantly augmented in SCI during ES (59 ± 5 ml) compared to PAS (46 ± 4 ml). The results of this study suggest that, in able-bodied humans, Group III and IV leg muscle afferents contribute to increased cardiac output during exercise primarily via augmented heart rate. In contrast, SCI achieve raised cardiac output during ES leg exercise via increased venous return in the absence of any change in heart rate.

Effect of Manipulation under Anesthesia of the First Knee in Staged Bilateral Total Knee Arthroplasty on Clinical Outcome and Satisfaction

2020 ◽  
Author(s):  
Jung-Won Lim ◽  
Yong-Beom Park ◽  
Dong-Hoon Lee ◽  
Han-Jun Lee
Keyword(s):  
Total Knee Arthroplasty ◽  
Patient Satisfaction ◽  
Clinical Outcome ◽  
Clinical Outcomes ◽  
Knee Arthroplasty ◽  
Knee Flexion ◽  
Functional Score ◽  
Manipulation Under Anesthesia ◽  
Total Knee

AbstractThis study aimed to evaluate whether manipulation under anesthesia (MUA) affect clinical outcome including range of motion (ROM) and patient satisfaction after total knee arthroplasty (TKA). It is hypothesized that MUA improves clinical outcomes and patient satisfaction after primary TKA. This retrospective study analyzed 97 patients who underwent staged bilateral primary TKA. MUA of knee flexion more than 120 degrees was performed a week after index surgery just before operation of the opposite site. The first knees with MUA were classified as the MUA group and the second knees without MUA as the control group. ROM, Knee Society Knee Score, Knee Society Functional Score, Western Ontario and McMaster Universities (WOMAC) score, and patient satisfaction were assessed. Postoperative flexion was significantly greater in the MUA group during 6 months follow-up (6 weeks: 111.6 vs. 99.8 degrees, p < 0.001; 3 months: 115.9 vs. 110.2 degrees, p = 0.001; 6 months: 120.2 vs. 117.0 degrees, p = 0.019). Clinical outcomes also showed similar results with knee flexion during 2 years follow-up. Patient satisfaction was significantly high in the MUA group during 12 months (3 months: 80.2 vs. 71.5, p < 0.001; 6 months: 85.8 vs. 79.8, p < 0.001; 12 months: 86.1 vs. 83.9, p < 0.001; 24 months: 86.6 vs. 85.5, p = 0.013). MUA yielded improvement of clinical outcomes including ROM, and patient satisfaction, especially in the early period after TKA. MUA in the first knee could be taken into account to obtain early recovery and to improve patient satisfaction in staged bilateral TKA.

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