Prevalence of chondromalacia patella according to patella type and patellofemoral geometry: a retrospective study.

BACKGROUND: The relationships between the morphometric structure of the patellofemoral joint, patella type and chondromalacia patella are still a matter of debate. OBJECTIVE: To identify the prevalence of chondromalacia patella by determining the patella type and making patellofemoral morphometric measurements. DESIGN AND SETTING: Retrospective cohort study in an orthopedics and traumatology clinic in Turkey, conducted between June 2017 and November 2019. METHODS: This study involved 562 knees of 522 patients with anterior knee pain (246 males and 316 females; mean age 46.59 years). The patients were grouped according to presence of chondromalacia patella (group I) or absence of chondromalacia patella (group II). The patella type, lateral trochlear inclination, medial trochlear inclination, trochlear angle, sulcus angle, patellar tilt and Insall-Salvati index were assessed. Group comparisons were made using chi-square tests or Student t tests. The r value was used to determine the magnitude of relationships between pairs of variables. RESULTS: Among the 562 knees evaluated, 265 (50.71%) presented type I patella, 195 (36.7%) type II, 100 (12.3%) type III and 2 (0.3%) type IV. Group I consisted of 448 knees and group II consisted of 114 knees. Significant differences were found between the groups in terms of age, gender, patella type and lateral inclination angles (P < 0.05). CONCLUSION: Detecting the patella type and making lateral inclination measurements in patients with anterior knee pain are of great importance for diagnosing suspected chondromalacia patella, particularly in the early degenerative period.

Chondromalacia patellae: current options and emerging cell therapies.

Chondromalacia patellae (CMP), also known as runner's knee, typically occurs in young patients, which is characterized by anterior knee pain (AKP) that is associated with visible changes in patellar cartilage. The initial pathological changes include cartilage softening, swelling, and edema. CMP is caused by several factors, including trauma, increased cartilage vulnerability, patellofemoral instability, bony anatomic variations, abnormal patellar kinematics, and occupation hazards. CMP may be reversible or may progress to develop patellofemoral osteoarthritis. Quadriceps wasting, patellofemoral crepitus, and effusion are obvious clinical indications. Additionally, radiological examinations are also necessary for diagnosis. Magnetic resonance imaging (MRI) is a non-invasive diagnostic method, which holds a promise in having the unique ability to potentially identify cartilage lesions. Modalities are conventionally proposed to treat cartilage lesions in the PF joint, but none have emerged as a gold standard, neither to alleviated symptoms and function nor to prevent OA degeneration. Recently, researchers have been focused on cartilage-targeted therapy. Various efforts including cell therapy and tissue emerge for cartilage regeneration exhibit as the promising regime, especially in the application of mesenchymal stem cells (MSCs). Intra-articular injections of variously sourced MSC are found safe and beneficial for treating CMP with improved clinical parameters, less invasiveness, symptomatic relief, and reduced inflammation. The mechanism of MSC injection remains further clinical investigation and is tremendously promising for CMP treatment. In this short review, etiology, MRI diagnosis, and treatment in CMP, especially the treatment of the cell-based therapies, are reviewed.

Patella-patellar tendon angle and lateral patella-tilt angle decrease patients with chondromalacia patella.

PURPOSE: The aim of the present study was to evaluate the effect of patellofemoral joint morphology and patellar alignment (lateral patellar tilt and sagittal patellar tilt) on the presence and stage of CP, and identify the differences between sexes. METHODS: MRI of 243 patients [146 men (60.1%)] were evaluated retrospectively. Patients were grouped as normal group without chondromalacia, group with mild chondromalacia (grades 1-2) and group with severe chondromalacia (grades 3-4). Sagittal patellofemoral alignment was assessed by the angle between the patella and patellar tendon (P-PTA), and the angle between the quadriceps tendon and patella (Q-PA). Patellar tilt was assessed by lateral patellar tilt angle (LPTA). In addition, patellofemoral joint morphology was evaluated by measuring trochlear depth (TD), trochlear sulcus angle (TSA) and patella angle (PA). RESULTS: P-PTA, Q-PA, LPTA and TD values were significantly lower in patients with severe chondromalacia than in patients with both normal and mild chondromalacia (P < 0.001). TSA values were significantly higher in patients with severe chondromalacia than those with both normal and mild chondromalacia (P < 0.001). TSA was higher and TD was lower in women compared to men (P < 0.001). LPTA and P-PTA were lower in women compared to men, and the difference was significant. There was no difference in PA between the two sexes. CONCLUSIONS: Patellar cartilage degeneration increases with trochlear dysplasia. There is a strong correlation between patellar malalignment (lateral patellar tilt and sagittal patellar tilt) and chondromalacia patella. Women are more prone to developing CP than men.

Relation of the chondromalatia patellae to proximal tibial anatomical parameters, assessed with MRI.

Background Magnetic resonance imaging (MRI) is a non-invasive highly sensitive tool for diagnosing chondromalacia patellae in the early stages. Many studies have evaluated patellar and trochlear morphology with different radiologic indices. We aimed to assess the discriminative power of tibial, patellar, and femoral indices in MRI for chondromalacia patellae. Patients and methods 100 cases of chondromalacia, as well as 100 age-matched controls among the patients who underwent knee MRI between February 2017 and March 2019, were included. The standard protocol of knee MRI was applied and the diagnosis of chondromalacia was made on MRI findings. Chondromalacia subjects were also classified as grade 1 to 4 according to the Modified Outerbridge's MRI grading system. We measured 25 MRI parameters in the knee and adjacent structures to determine the relation between chondromalacia patellae and anatomical MRI parameters. Results Tibial slope, trochlear depth, lateral trochlear inclination, and lateral patellar tilt angle had significant correlation with chondromalacia. Any increase in lateral trochlear inclination and lateral patellar tilt angle could increase the probability of the disease (Odds ratio [OR] 1.15, 1.13; 95% CI: 1.03-1.30; 1.02-1.26, respectively), while any increase in medial tibial slope and trochlear depth could decrease the probability of chondromalacia (OR 0.85, 0.06; 95% CI: 0.73-0.98, 0.02-0.17, respectively). We also designed a model for the severity of disease by using the patellar height index (relative odds ratio: 75.9). Conclusions The result of this study showed the novelty role of tibial anatomy in developing chondromalacia and its mechanism. We also concluded that patellar height might be an important factor in defining disease severity.

Analysis of patellofemoral arthrokinematic motion quality in open and closed kinetic chains using vibroarthrography.

BACKGROUND: Knee movements performed in open (OKC) and closed (CKC) kinetic chains generate various patterns of muscle activities and especially distinct contact stresses in the patellofemoral joint (PFJ). In contrast to these features, the arthrokinematic motion quality (AMQ) of the PFJ has not been compared between mentioned conditions. In this study we performed vibroarthrographic analysis of AMQ in movements performed in OKC and CKC, in healthy subjects and individuals with chondromalacia patellae, to assess which of the test conditions is more efficient in differentiation between healthy and deteriorated joints. Moreover, our analysis will broaden the knowledge related to behavior of normal and pathological synovial joints during motion with and without weight bearing. It is an essential issue, due to the recently observed significant interest in comparing potential benefits and limitations of CKC and OKC exercises as they relate to lower extremity rehabilitation. METHODS: 100 subjects (62 healthy controls and 38 subjects with PFJ chondromalacia) were enrolled. During repeated knee flexion/extension motions performed in OKC (in a sitting position) and CKC (sit-to-stand movements), the vibroarthrographic signals were collected using an accelerometer and described by variability (VMS), amplitude (R4), and spectral power in 50-250 Hz (P1) and 250-450 Hz (P2) bands. RESULTS: Significant differences in VMS [V], R4 [V], P1 [V2/Hz] and P2 [V2/Hz] between OKC and CKC were found (0.0001, 0.969. 0.800 0.041 vs 0.013, 3.973, 6.790, 0.768, respectively, P < 0.001). Moreover, in both analyzed load-related conditions the subjects with chondromalacia were characterized by significantly higher values of all parameters, when compared to controls (P < 0.001), with effect size values over 0.6. CONCLUSIONS: We showed that motion of the physiological, unloaded PFJ articular surfaces in OKC is nearly vibrationless, which corresponds with optimal AMQ of PFJ, while loaded movements in CKC are characterized by a higher vibroacoustic emission level. Moreover, chondral lesions should be considered as an increased friction-related, aggravating factor of AMQ, which is critical in CKC movements under load. Nonetheless, OKC and CKC conditions are characterized by large effect sizes, and provide an efficient test frame for differentiating physiological knees and joints with chondral lesions.

Analysis and multiclass classification of pathological knee joints using vibroarthrographic signals.

BACKGROUND AND OBJECTIVE: Vibroarthrography (VAG) is a method developed for sensitive and objective assessment of articular function. Although the VAG method is still in development, it shows high accuracy, sensitivity and specificity when comparing results obtained from controls and the non-specific, knee-related disorder group. However, the multiclass classification remains practically unknown. Therefore the aim of this study was to extend the VAG method classification to 5 classes, according to different disorders of the patellofemoral joint. METHODS: We assessed 121 knees of patients (95 knees with grade I-III chondromalacia patellae, 26 with osteoarthritis) and 66 knees from 33 healthy controls. The vibroarthrographic signals were collected during knee flexion/extension motion using an acceleration sensor. The genetic search algorithm was chosen to select the most relevant features of the VAG signal for classification. Four different algorithms were used for classification of selected features: logistic regression with automatic attribute selection (SimpleLogistic in Weka), multilayer perceptron with sigmoid activation function (MultilayerPerceptron), John Platt's sequential minimal optimization algorithm implementation of support vector classifier (SMO) and random forest tree (RandomForest). The generalization error of classification algorithms was evaluated by stratified 10-fold cross-validation. RESULTS: We obtained levels of accuracy and AUC metrics over 90%, more than 93% sensitivity and more than 84% specificity for the logistic regression-based method (SimpleLogistic) for a 2-class classification. For the 5-class method, we obtained 69% and 90% accuracy and AUC respectively, and sensitivity and specificity over 91% and 69%. CONCLUSIONS: The results of this study confirm the high usefulness of quantitative analysis of VAG signals based on classification techniques into normal and pathological knees and as a promising tool in classifying signals of various knee joint disorders and their stages.

A new MRI grading system for chondromalacia patellae.

Background Chondromalacia patellae is a very common disorder. Although magnetic resonance imaging (MRI) is widely used to investigate patellar cartilage lesions, there is no descriptive MRI-based grading system for chondromalacia patellae. Purpose To propose a new MRI grading system for chondromalacia patellae with corresponding high resolution images which might be useful in precisely reporting and comparing knee examinations in routine daily practice and used in predicting natural course and clinical outcome of the patellar cartilage lesions. Material and Methods High resolution fat-saturated proton density (FS PD) images in the axial plane with corresponding T2 mapping images were reviewed. A detailed MRI grading system covering the deficiencies of the existing gradings has been set and presented on these images. Two experienced observers blinded to clinical data examined 44 knee MR images and evaluated patellar cartilage changes according to the proposed grading system. Inter- and intra-rater validity testing using kappa statistics were calculated. Results A descriptive and detailed grading system with corresponding FS PD and T2 mapping images has been presented. Inter-rater agreement was 0.80 (95% confidence interval [CI], 0.71-0.89). Intra-rater agreements were 0.83 (95% CI, 0.74-0.91) for observer A and 0.79 (95% CI, 0.70-0.88) for observer B (k-values). Conclusion We present a new MRI grading system for chondromalacia patellae with corresponding images and good inter- and intra-rater agreement which might be useful in reporting and comparing knee MRI examinations in daily practice and may also have the potential for using more precisely predicting prognosis and clinical outcome of the patients.

Association between trochlear morphology and chondromalacia patella: an MRI study.

This study aimed to compare trochlear morphology seen in magnetic resonance imaging between patients with chondromalacia patella and age-matched control patients without cartilage lesion. Trochlear morphology was evaluated using the lateral trochlear inclination, medial trochlear inclination, sulcus angle and trochlear angle on the axial magnetic resonance images. Consequently, an association between abnormal trochlear morphology and chondromalacia patella was identified in women. In particular, women with flattened lateral trochlea are at an increased risk of patellar cartilage structural damage.

Sagittal plane tilting deformity of the patellofemoral joint: a new concept in patients with chondromalacia patella.

PURPOSE: The aims of this study were to evaluate sagittal plane alignment in patients with chondromalacia patella via magnetic resonance imaging (MRI), analyse the relationships between the location of the patellar cartilaginous lesions and sagittal alignment and finally investigate the relationships between the sagittal plane malalignment and patellofemoral loadings using by finite element analysis. METHODS: Fifty-one patients who were diagnosed with isolated modified Outerbridge grade 3-4 patellar chondromalacia based on MRI evaluation and 51 control subjects were evaluated. Chondromalacia patella patients were divided into three subgroups according to the chondral lesion location as superior, middle and inferior. The patella-patellar tendon angle (P-PT) was used for evaluation of sagittal alignment of patellofemoral joint. Each subgroup was compared with control group by using P-PT angle. To investigate the biomechanical effects of sagittal plane malpositioning on patellofemoral joint, bone models were created at 30°, 60° and 90° knee flexion by using mean P-PT angles, which obtained from patients with chondromalacia patellae and control subjects. The total loading and contact area values of the patellofemoral joints were investigated by finite element analysis. RESULTS: The mean age of all participants was 52.9 ± 8.2 years. The mean P-PT angle was significantly lower in chondromalacia group (142.1° ± 3.6°) compared to control group (144.5° ± 5.3°) (p = 0.008). Chondral lesions were located in superior, middle and inferior zones in 16, 20 and 15 patients, respectively. The mean P-PT angles in patients with superior (141.8 ± 2.7) and inferior subgroups (139.2 ± 2.3) were significantly lower than the values in the control group (p < 0.05). The contact area values were detected higher in models with chondromalacia than in the control models at the same flexion degrees. There were increased loadings at 30° and 90° flexions in the sagittal patellar tilt models. CONCLUSION: This study revealed that sagittal plain malpositioning of the patellofemoral joint might be related to chondromalacia, especially in the presence of lesions in the upper and lower part of the patella. This condition leads to supraphysiological loadings on the patellofemoral joint. Sagittal patellar tilt should be considered in the evaluation and management of patellar cartilage defects. Taking sagittal plane malalignment into consideration in patellofemoral joint evaluation will enable us to design new physical and surgical modalities. LEVEL OF EVIDENCE: IV.

Joint motion quality in vibroacoustic signal analysis for patients with patellofemoral joint disorders.

BACKGROUND: Chondromalacia, lateral patellar compression syndrome and osteoarthritis are common patellofemoral joint disorders leading to functional and/or structural disturbances in articular surfaces. The objective of the study was to evaluate their impact on joint motion quality via the vibroacoustic signal generated during joint movement analysis. METHODS: Seventy-three patients (30 with chondromalacia, 21 with lateral patellar compression syndrome, and 22 with osteoarthritis) and 32 healthy controls were tested during flexion/extension knee motion for vibroacoustic signals using an acceleration sensor. Estimated parameters: variation of mean square (VMS), difference between mean of four maximum and mean of four minimum values (R4), power spectral density for frequency of 50-250 Hz (P1) and 250-450 Hz (P2) were analyzed. RESULTS: Vibroacoustic signals recorded for particular disorders were characterized by significantly higher values of parameters in comparison to the control group. Moreover, differences were found among the various types of patellofemoral joint disturbances. Chondromalacia and osteoarthritis groups showed differences in all parameters examined. In addition, osteoarthritis patients exhibited differences in VMS, P1 and P2 values in comparison to lateral patellar compression syndrome patients. However, only the value of R4 was found to differ between knees with lateral patellar compression syndrome and those with chondromalacia. CONCLUSION: Our results suggest that particular disorders are characterized by specific vibroacoustic patterns of waveforms as well as values of analyzed parameters.

Vibroarthrography in the evaluation of musculoskeletal system - a pilot study.

BACKGROUND. Disorders of the articular surfaces are associated with impaired quality of joint motion and joint play. Crepitations are the hallmark clinical sign. This paper aims to present the possibilities of using vibroacoustic signal analysis in assessing the function of articular surfaces in the course of disorders of the knee and shoulder. MATERIAL AND METHODS. The study involved 30 people, 10 for each of the following disorders: patellar chondromalacia (Ch), meniscal tears (Mc), and degenerative changes of the glenohumeral joint (GH). A control group (K1-K3) was matched to each dysfunctional group. 6-second vibroacoustic signals (VAG) were recorded during motion in particular joints. The resulting time series were filtered (50-1000 Hz) and the following parameters were calculated: variance-mean-square (VMS), the mean of the four lowest and four highest values (R4) and the total spectral power density in the 50-250 Hz (P1) and 250-450 Hz (P2) ranges. RESULTS. Depending on the type of disorder, VAG signals in the dysfunctional groups were characterized by higher variability, amplitude and frequency than was the case in the control groups. This is reflected in the values of all parameters (VMS, R4, P1, P2), which were significantly higher in the Ch, Mc and GH groups compared to K1-K3. CONCLUSIONS. 1. Vibroarthrography can be a useful tool for accurate and objective assessment of the quality of joint motion. 2. The non-invasive nature of vibroarthrography allows the use of this method to monitor the effects of the treatment of joint structures.

The effects of quadriceps contraction on different patellofemoral alignment subtypes: an axial computed tomography study.

STUDY DESIGN: Controlled laboratory study. BACKGROUND: The effect of quadriceps contraction on patellar alignment in patients with patellofemoral pain syndrome (PFPS) is debated and may vary based on patellar alignment subtypes measured with the quadriceps relaxed. OBJECTIVES: To determine if the effects of quadriceps contraction on patellar alignment differs (1) with respect to patellar alignment subtype in individuals with PFPS and (2) between symptomatic and asymptomatic knees in individuals with unilateral PFPS. METHODS AND MEASURES: Seventy-eight individuals, 47 with bilateral and 31 with unilateral PFPS, participated in the study. On axial computed tomography images with the knee in extension with quadriceps relaxed as well as contracted, patellar lateral condyle index (PLCI) and patellar tilt angle (PTA) were measured and analyzed. Based on the median PLCI and PTA alignment values measured with quadriceps relaxed for the 78 subjects, 4 subgroups of subjects were created: type 1, laterally displaced; type 2, laterally displaced and tilted; type 3, laterally tilted; and type 4, neither. RESULTS: Quadriceps contraction caused an increase in PLCI in all patellar alignment types (P<.01), with no difference in the magnitude of the increase between types (P>.05). PTA decreased with quadriceps contraction in the subjects with the type 3 initial patellar alignment (P<.01), with a significant difference in the change in patellar alignment between the subjects with type 3 and type 1 initial patellar alignment (P=.004). For the 31 subjects with unilateral PFPS, quadriceps contraction caused a similar change in PLCI and PTA in both the symptomatic and asymptomatic knees. CONCLUSIONS: The initial position of the patella with the quadriceps relaxed did not influence the change in PLCI with quadriceps contraction. For the 31 subjects with PFPS, there was no difference in initial alignment as well as in change of alignment with quadriceps contraction between symptomatic and asymptomatic knees.

[Klippel-Trenaunay syndrome and bone scintigraphy. A case report]. / Síndrome de Klippel-Trenaunay y gammagrafía ósea. A propósito de un caso.

A 34-year-old man with Klippel-Trenaunay syndrome (KTS) was performed three bone scintigraphies. The first one to evaluate the possibility of avascular necrosis of the femoral head. Secondly, to dismiss a reflex sympathetic dystrophy in the affected lower limb and finally, due to knee pain. Magnetic resonance of pelvis and knee and biopsy of iliac spine were performed too.