Patellofemoral Pain

Effects of neuromuscular electrical stimulation on patellofemoral pain: A randomized controlled trial

INTRODUCTION

Patellofemoral Pain (PFP) is a common dysfunction that can compromise the performance of daily activities. Neuromuscular electrical stimulation (NMES) has been proposed as a complementary tool in the therapeutic approach.

OBJECTIVE

To analyze the effects of adding NMES to therapeutic exercises in women with PFP.

METHODS

Randomized controlled trial involving 34 women with PFP (mean age 23.8 ± 4.1), randomly assigned to two groups: exercises combined with NMES (ESG) and exercises only (ExG). The ExG followed an exercise protocol, while the ESG performed the same exercises combined with NMES. Interventions were performed twice a week for eight weeks. Primary outcome measures included pain and functional disability, while secondary outcomes encompassed electromyographic activity of the quadriceps and hip abductors, along with isokinetic performance. Assessments were performed before the intervention, after 4 and 8 weeks from the start of the protocol and 8 weeks after the conclusion of the treatment.

RESULTS

We did not observe difference between the groups in any of the analyzed variables. Both groups showed a reduction in pain and an improvement in functional disability during intragroup comparisons.

CONCLUSION

A reduction in pain and an improvement in functional disability were observed; however, there was no additional effect of NMES.

TRIAL REGISTRATION

NCT03918863.

Clinical value of questionnaires & physical tests for patellofemoral pain: Validity, reliability and predictive capacity

OBJECTIVES

To determine the most appropriate method of functional assessment for "patellofemoral pain" (PFP)/"chondromalacia patella" for its diagnostic value, (validity, reliability, sensitivity, specificity, predictive value and clinical applicability); to outline initial interpretations of the questionnaires and their appropriateness, through the cut-off points determined in their scores based on physical test and Magnetic Resonance Imaging (MRI); to establish which methods should be used in conjunction with each other to obtain clinical diagnoses that are robust effective and efficient.

METHODS

(1)Intra- and inter-observer reliability and of the relationship among PFP questionnaires/physical tests validated. (2)Predictive capacity of the questionnaires. Subject: 113 knees with PFP, assessed using "Knee-injury-and-Osteoarthritis Outcome-Score-for-Patellofemoral-pain-and-osteoarthritis" (KOOS-PF), "Kujala-Patellofemoral-Score" (KPS), "Victorian-Institute-of-Sports-Assessment-for-Patellar-tendons-questionnaire" (VISA-P), and the physical tests: "patellar-palpation", "patellar-tilt", "patellar-apprehension", "Clarke" and "squat".

RESULTS

Questionnaires correlations themselves was 0.78

CONCLUSIONS

KOOS-PF, KPS and VISA-P demonstrated their diagnostic value in PFP/chondromalacia (validity, reliability, sensitivity, specificity, predictive value and clinical applicability). KOOS-PF was the most versatile, and the most appropriate in mild cases and for early detection and prevention. Squat was the best due to its reliability and clinical relationship with the questionnaires, which predicted it correctly. The functional assessment tools discussed should be applied by combining them with each other.

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MESH Headings

• Humans
• Patellofemoral Pain Syndrome
• Reproducibility of Results
• Cartilage Diseases
• Osteoarthritis
• Surveys and Questionnaires
• Patellofemoral Joint

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Affiliation(s)

Gema Chamorro-Moriana Department of Physiotherapy, Faculty of Nursing, Physiotherapy and Podiatry, University of Seville, Seville, Spain Research Group “Area of Physiotherapy CTS305”, Spain
Fernando Espuny-Ruiz Department of Physiotherapy, Faculty of Nursing, Physiotherapy and Podiatry, University of Seville, Seville, Spain
Carmen Ridao-Fernández Department of Physiotherapy, Faculty of Nursing, Physiotherapy and Podiatry, University of Seville, Seville, Spain Research Group “Area of Physiotherapy CTS305”, Spain
Eleonora Magni Department of Nursing, Faculty of Nursing, Physiotherapy and Podiatry, University of Seville, Seville, Spain

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Morphologic Evaluation of the Patella: The Impact of Gender and Age

Introduction

The patellofemoral joint is a complex joint that plays a crucial role in knee joint function and stability. This study aims to describe the MRI characteristics of the patellofemoral joint in Vietnamese adults.

Subjects and Methodology

A cross-sectional study was conducted on 280 patients at Hue UMP Hospital from May 2020 to May 2021. All patients underwent knee MRI using Siemens Magnetom Amira 1.5 Tesla. The evaluation parameters included the morphology of the patella and the femoral trochlea.

Results

The study found that the morphological parameters of the patellar joint varied significantly between genders and age groups. The mean largest patellar transverse diameter was 4.26 ± 0.37 cm, the average length of the lateral joint facet was 2.5 ± 0.26 cm, and the medial joint facet was 2.0 ± 0.25 cm. The patellar height was 4.07 ± 0.35 cm. The indexes of patellar morphology were higher in men than in women, except for the lateral-medial facet ratio. The most common Wiberg classification was type B (63.9%), followed by type C (25.4%), and type A was the least common (10.7%). There was a statistically significant difference in the patellar measurements between different age groups. There was a weak negative linear correlation between the dimensions of the largest transverse diameter, the length of the articular surface, the patellar articular angle, and the age of the patient. Additionally, there was a moderate inverse linear relationship between patellar height and patient age.

Conclusion

This study highlights the significant variations in patellar morphology based on gender and age. The findings emphasize the importance of careful assessment and consideration of these variations in the imaging evaluation of the patellofemoral joint.

Electromyostimulation With Blood Flow Restriction for Patellofemoral Pain Syndrome in Active Duty Military Personnel: A Randomized Controlled Trial

INTRODUCTION

The high prevalence of patellofemoral pain in military service members results in strength loss, pain, and functional limitations during required physical performance tasks. Knee pain is often the limiting factor during high-intensity exercise for strengthening and functional improvement, thus limiting certain therapies. Blood flow restriction (BFR) improves muscle strength when combined with resistance or aerobic exercise and may serve as a possible alternative to high-intensity training during recovery. In our previous work, we showed that Neuromuscular electrical stimulation (NMES) improves pain, strength, and function in patellofemoral pain syndrome (PFPS), which led us to ask whether the addition of BFR to NMES would result in further improvements. This randomized controlled trial compared knee and hip muscle strength, pain, and physical performance of service members with PFPS who received BFR-NMES (80% limb occlusion pressure [LOP]) or BFR-NMES set at 20 mmHg (active control/sham) over 9 weeks.

METHODS

This randomized controlled trial randomly assigned 84 service members with PFPS to one of the two intervention groups. In-clinic BFR-NMES was performed two times per week, while at-home NMES with exercise and at-home exercise alone were performed on alternating days and omitted on in-clinic days. The outcome measures included strength testing of knee extensor/flexor and hip posterolateral stabilizers, 30-second chair stand, forward step-down, timed stair climb, and 6-minute walk.

RESULTS

Improvement was observed in knee extensor (treated limb, P < .001) and hip strength (treated hip, P = .007) but not flexor over 9 weeks of treatment; however, there was no difference between high BFR (80% LOP) and BFR-sham. Physical performance and pain measures showed similar improvements over time with no differences between groups. In analyzing the relationship between the number of BFR-NMES sessions and the primary outcomes, we found significant relationships with improvements in treated knee extensor strength (0.87 kg/session, P < .0001), treated hip strength (0.23 kg/session, P = .04), and pain (-0.11/session, P < .0001). A similar set of relationships was observed for the time of NMES usage for treated knee extensor strength (0.02/min, P < .0001) and pain (-0.002/min, P = .002).

CONCLUSION

NMES strength training offers moderate improvements in strength, pain, and performance; however, BFR did not provide an additive effect to NMES plus exercise. Improvements were positively related to the number of BFR-NMES treatments and NMES usage.

Knee skin temperature response of patients with bilateral patellofemoral syndrome before and after heat and cold stress

Patellofemoral Pain Syndrome is characterized by the presence of pain in the front area of the knee, which occurs when performing common activities such as climbing stairs, and bending the knees, among others. The objective of this research was to evaluate the detection capability of infrared thermography in patients with Patellofemoral Pain Syndrome, in the baseline state, as well as after the application of thermal stress. The investigation was conducted in 48 patients, who were subdivided into four groups (n = 12). Two subgroups were healthy patients and two with Patellofemoral Pain Syndrome. For the diagnosis of the syndrome, a manual evaluation was performed using the Zohlen test and Q angle measurement. Subsequently, cold stress was applied for 10 min to a healthy subgroup and an experimental subgroup. The remaining two subgroups were subjected to heat stress for 15 min. Thermographic images of the lower extremities were acquired at seven time points, at baseline, immediately after application of thermal stress and then every 3 min until 15 min were completed. It was observed that patients presented Patellofemoral Pain Syndrome bilaterally. After statistical analysis, it was found that there were no significant differences in baseline temperature between the groups. However, for heat stress, a higher temperature was observed in the group with Patellofemoral Pain Syndrome (p < 0.05) in the recovery period, and in the case of cold stress, only a lower temperature in the left knee immediately after the application. In conclusion, it is not possible to detect patellofemoral syndrome bilaterally in the baseline state by thermography and neither is it evident in cold stress. However, after heat stress, thermal recovery is lower for the PFPS group, so it would be susceptible to detection.

Whole-body vibration provides additional benefits to patients with patellofemoral pain: A protocol for systematic review and meta analysis of randomized controlled trials

BACKGROUND

The efficacy of the whole-body vibration (WBV) training for patients with patellofemoral pain (PFP) remains controversial. For this reason, we applied a meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy of WBV training in patients with PFP.

METHODS

Relevant studies found within PubMed, EMBASE, the Cochrane Library and Web of Science were examined from January 1, 1990 to December 30, 2021. Two evaluators independently screened the literatures, extracted relevant data and assessed the methodological quality of respective studies. Meta-analysis was conducted using RevMan 5.4 software.

RESULTS

A total of 5 RCTs with 174 patients were included. When comparing with exercise alone, WBV training in combination with exercise provided better reduction of pain assessed by visual analogue scale score (P = .04). There were no differences regarding changes of Kujala patellofemoral score, the physical component summary score for physical health, and the mental component summary score for mental health (P = .08, 0.76, 0.65 respectively) between patients with WBV training and those without WBV training.

CONCLUSIONS

Compared to the sole performance of exercise, WBV training in combination with exercise showed better pain reduction, but no superior improvement in function and on quality of life.

Efficacy of Patellar Taping and Electromyographic Biofeedback Training at Various Knee Angles on Quadriceps Strength and Functional Performance in Young Adult Male Athletes with Patellofemoral Pain Syndrome: A Randomized Controlled Trial

Background

The severity of the articular lesion is the single most essential element in investigating the extent of flexion that is required for activities. However, a prior study found no differences in muscle strength gains of quadriceps muscles at different knee angles in people with patellofemoral pain syndrome (PFPS).

Objective

The effects of patellar taping and electromyographic biofeedback (EMG-BF)-guided isometric quadriceps strengthening at different knee angles (e.g., 30°, 60°, and 90° of knee flexion) on quadriceps strength and functional performance in people with PFPS were compared in this single-blind randomized controlled parallel trial.

Methods

Sixty adult male athletes with PFPS (age: 26.9 ± 1.4 years) were randomly divided into two groups. The experimental group (n = 30) received patellar taping and EMG-BF-guided isometric contraction exercise at 30°, 60°, and 90° angles, and the control group (n = 30) received sham patellar taping without EMG-BF-guided exercises for six weeks. Pain intensity, knee function, muscle strength, and the single-leg triple hop (SLTH) test were assessed.

Results

The pain intensity and SLTH scores between the groups were significantly different at the end of the trial (p ≤ 0.001). The EMG-BF and control groups had mean pain scores of 1.3 (0.8) and 4.5 (0.8), respectively. The EMG-BF and control groups had mean functional scores of 80.4 (5.1) and 69.1 (6.1), respectively. The mean SLTH score for the EMG-BF group was 540.7 (51.2) and for the control group it was 509.4 (49.8) after the trial. Quadriceps muscle strength was significantly higher in those who performed quadriceps strength training at 60° of knee flexion after six weeks than in those who performed strength training at 30° or 90° of knee flexion.

Conclusion

The findings indicated that individuals who trained their quadriceps at a 60° knee angle had significantly stronger quadriceps muscles than individuals who trained at 30° or 90° of knee flexion. Trial Registration. This trial is registered at Clinical Trials.gov under the identifier NCT05055284.

Anterior knee pain in runners after a half-marathon race

BACKGROUND

Anterior knee pain has been associated with sports activity, especially long-distance running and endurance sports. It is important to determine the incidence of anterior knee pain (AKP) in runners after a half-marathon race and identify possible risk factors associated.

METHODS

Cross-sectional study where runners from a half marathon race were randomly invited to participate. Participants were recruited at the race kit pickup site the day before the race. Eligible participants completed a survey regarding demographic information, running experience and training details. An orthopedic surgeon performed a physical examination and recorded the medical history. At the finish line, the participants were evaluated again for possible new injuries.

RESULTS

A total of 205 runners were included in the study, with a 98.5% follow-up rate (n = 203). 24% of runners had an injury at the end of the race (n = 49). Anterior knee pain was the most frequent injury (n = 12), followed by iliotibial band syndrome (n = 10), muscle cramps (n = 7) and hamstring tears (n = 4). Anterior knee pain had a statistically significant association with insufficient stretching of the hamstrings (p = 0.048) and finishing the race in more than 2 h (p = 0.014).

CONCLUSIONS

Anterior knee pain was the most frequent new injury in the half-marathon runners after the competition. Spending more than 2 h to finish the race and stretching the hamstrings by less than 70° in the supine position were risk factors for anterior knee pain.

Internal Fixation of Lateral Trochlear Groove Osteochondritis Dissecans With Simultaneous Lateral Retinacular Lengthening in Adolescent Athletes

BACKGROUND

The goals of operative treatment for the adolescent athlete with unstable osteochondritis dissecans (OCD) lesion are rigid fixation and prevention of recurrence.

PURPOSE

To evaluate clinical and radiological outcomes of internal fixation of lateral trochlear groove OCD with simultaneous lateral retinacular lengthening.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Adolescent athletes who had undergone internal fixation and simultaneous lateral retinacular lengthening for an unstable OCD lesion of the lateral trochlear groove were retrospectively reviewed. Subjective assessments included the Lysholm score, International Knee Documentation Committee (IKDC) subjective score, Tegner activity scale, and an athletic questionnaire. Functional tests included isokinetic muscle strength, single-leg hop for distance, single-leg vertical jump, and Y-balance. Pre- and postoperative radiographs and magnetic resonance images were reviewed.

RESULTS

The mean ± SD age of the 17 patients included in this study was 15.9 ± 0.9 years; last clinical follow-up duration was 37.7 ± 8.1 months. At the last follow-up, the Lysholm score improved from 68.7 ± 15.3 to 93.4 ± 12.4 and the IKDC subjective score from 60.2 ± 14.7 to 88.7 ± 12.7 (P < .001). The mean Tegner activity scale score was 9.4 ± 0.5 before injury and 8.9 ± 1.2 at the last follow-up (P = .059). The limb symmetry indices of isokinetic muscle strength, single-leg hop for distance, single-leg vertical jump, and Y-balance improved at the last follow-up; the mean limb symmetry index was ≥85% in each functional test. Regarding the athletic questionnaire, 16 (94.1%) patients were satisfied with the surgery. At the last follow-up, 2 patients had higher ability after returning to sports, 11 had the same ability, and 3 had lower ability than the preinjury level. Postoperative magnetic resonance imaging at 12-month follow-up showed that the OCD lesion appeared healed in 7 (41.2%) patients and partially healed in 9 (52.9%).

CONCLUSION

Internal fixation of lateral trochlear groove OCD with simultaneous lateral retinacular lengthening in adolescent athletes achieved satisfactory clinical and radiological outcomes. Therefore, this combined surgical technique could be considered an effective treatment for lateral trochlear groove OCD, with a high rate of return to sport.

The effects of virtual reality training on clinical indices and brain mapping of women with patellofemoral pain: a randomized clinical trial

Background

Virtual reality training (VRT) is a new method for the rehabilitation of musculoskeletal impairments. However, the clinical and central effects of VRT have not been investigated in patients with patellofemoral pain (PFP). To comprehensively assess the effects of VRT on clinical indices and brain function, we used a randomized clinical trial based on clinical and brain mapping assessment.

Methods

Twenty-six women with PFP for more than 6 months were randomly allocated to 2 groups: intervention and control. The intervention consisted of lifestyle education + 8 weeks VRT, in 24 sessions each lasting 40 min of training, whereas the control group just received lifestyle education. The balance was the primary outcome and was measured by the modified star excursion balance test. Secondary outcomes included pain, function, quality of life, and brain function which were assessed by visual analogue scale, step down test and Kujala questionnaire, SF-36, and EEG, respectively. Pre-intervention, post-intervention and follow-up (1 month after the end of the intervention) measurements were taken for all outcome measures except EEG, which was evaluated only at pre-intervention and post-intervention). Analyses of variance was used to compare the clinical outcomes between the two groups. The independent t-test also was used for between group EEG analyses.

Results

Balance score (P < 0.001), function (P < 0.001), and quality of life (P = 0.001) improved significantly at post-intervention and 1 month follow-up in the VRT group compared with the control group. VRT group showed a significantly decreased pain score (P = 0.004). Alpha (P < 0.05) and theta (P = 0.01) power activity also increased in the brain of the VRT group.

Conclusion

This study demonstrated that long term VRT was capable of improving both clinical impairments and brain function in patients with PFP. Therefore, therapists and clinicians can use this method as a more holistic approach in the rehabilitation of PFP.

Trial registration

IRCT, IRCT20090831002391N40. Registered 23 / 10 / 2019.

A Protocol to Systematic Radiographic Assessment of Primary Total Knee Arthroplasty

Although total knee arthroplasty (TKA) is considered one of the most successful procedures, however, a subset of patients are unsatisfied with the results, even with the introduction of new technologies and implant designs. Radiological assessment of TKA is still considered the most prevalent imaging modality for evaluating the knee joint pre-and postoperatively. Assessment of various angles and indices which could be measured in different radiographic views of the knee provides valuable information about the alignment of the entire limb and the individual prosthetic components, more so in the light of recent nuanced concepts of technique, alignment, and balance. This review article aims to present a comprehensive yet systematic approach to the most useful radiographic parameters for assessing the knee preoperatively and post-TKA by explaining the tools and techniques used for measuring various angles, indices and ratios in the coronal, sagittal and axial planes for diagnosis, preoperative planning, postoperative assessment, and routine follow-up. The protocol we followed in this review entailed first reporting the possible applications and software which could help in measuring these variables, then we mentioned the required series of knee radiographs. For the desired variables, we divided the assessment according to each plane, and in each, we reported the optimum position of the desired radiographic view followed by determining the axis and lines which will later form the desired angles to be measured; finally, we collected all the measurements in a table with the native knee values and the most accepted values after TKA.

Cross-cultural translation and validation of the Spanish version of the patellofemoral pain and osteoarthritis subscale of the KOOS (KOOS-PF)

Objective

The aim of this study was to translate to Spanish the patellofemoral pain and osteoarthritis subscale of the knee injury and osteoarthritis outcome score (KOOS-PF) and validate this Spanish version of a disease-specific patient-reported outcome measure (PROM) for patellofemoral pain.

Results

The KOOS-PF was translated to Spanish and sixty patients with patellofemoral pain and/or osteoarthritis accepted to complete the questionnaire. 1-week later 58 patients answered the questions again for the test–retest reliability validation and finally 55 patients completed 1-month later for the responsiveness assessment. The Spanish version showed very good internal consistency (Cronbach’s alpha: 0.93) and test–retest reliability (intraclass correlation coefficient: 0.82). Responsiveness was confirmed, showing a strong correlation with the global rating of change (GROC) score (r 0.64). The minimal detectable change was 11.1 points, the minimal important change was 17.2 points, and there were no floor or ceiling effects for the score.

Current Evidence Does Support the Use of KT to Treat Chronic Knee Pain in Short Term: A Systematic Review and Meta-Analysis

Objective

To demonstrate whether KT is better than placebo taping, nonelastic taping, or no taping in reducing pain.

Methods

PubMed, Embase, Web of Science, the Cochrane Central Library, and ClinicalTrials.gov were systematically searched up to 20 October 2020 for randomized controlled studies that used KT to treat chronic knee pain according to PRISMA guidelines. We extracted the mean differences and SD in pretreatment and posttreatment for selected outcomes measured in the experimental and control groups for subsequent meta-analyses.

Results

In total, 8 studies involving 416 participants fulfilled the inclusion criteria. Our results indicated that KT is better than other tapings (placebo taping or nonelastic taping) in the early four weeks. The mean difference was −1.44 (95% CI: −2.04–−0.84, I² = 49%, P ≤ 0.01). Treatment methods which were performed for more than six weeks (0.16 (95% CI: −0.35–0.68, I² = 0%, P=0.53)) show no significant difference in reducing pain. In studies in which visual analogue scale was measured, a positive effect was observed for KT combined with exercise program training (−3.27 (95% CI: −3.69–2.85, I² = 0%, P < 0.05)).

Conclusion

KT exhibited significant but temporary pain reduction.

Joint position sense in individuals with anterior knee pain

BACKGROUND

Anterior knee pain (AKP) commonly affects both physically active and sedentary individuals and the aetiology is unknown. Altered joint position sense (JPS) impacts accurate motor action and knee joint stability. It is unclear whether people with AKP have altered JPS.

OBJECTIVE

The aim of our study was to investigate JPS in the knees of individuals with AKP.

METHOD

A descriptive cross-sectional study measured JPS in 25 participants with unilateral or bilateral AKP. JPS was measured using active JPS testing during single leg squat (SLS) and active knee extension (AKE) in sitting. Target angles (TA) were self-determined based on each participant's capabilities. The absolute error (AE) was the main outcome measure. Impaired JPS was classified as an AE equal to or greater than five degrees.

RESULTS

There were no significant differences in JPS when comparing the affected and unaffected knees in participants with AKP (p > 0.05). However, a subgroup of participants with altered knee JPS was identified. There was a tendency towards greater knee flexion in the TAs of knees without AKP.

CONCLUSION

Our results showed that JPS is not significantly more impaired in knees with AKP compared with knees without AKP in a group of individuals with AKP. A subgroup with altered JPS in knees with and without AKP was identified. This finding could be because of compensatory gait patterns and the precision of the Vicon 3D motion analysis system.

CLINICAL IMPLICATIONS

Joint position sense should be assessed bilaterally in individuals with AKP.

Quadriceps architecture in individuals with patellofemoral pain: A systematic review

OBJECTIVES

To identify differences in architectural parameters (size, fiber/pennation angle, fiber length, and echogenicity) of the quadriceps muscle, as a whole or any individual part of it, using imaging techniques in individuals with patellofemoral pain (PFP) compared to contralateral, asymptomatic limb or separate control group.

BACKGROUND

Quadriceps muscles imbalance and weakness were proposed as risk factors for developing PFP. Although the muscle architecture (size, pennation/fiber angle and fiber length) is highly associated with skeletal muscle strength, it is not clear whether atrophy or any changes in architectural parameters of the quadriceps are presented in the PFP patients.

METHODS

Observational studies in which the total size of the quadriceps or individual parts of it were measured using imaging techniques in the PFP patients were included in this review. Electronic databases (PubMed, SCOPUS, PEDro, CINAHL, WOS, and EMBASE) were searched between January 1990 and December 2019 with no restriction of language. Study selection and data extraction and quality assessment were conducted by two independent reviewers.

RESULTS

Five cross-sectional studies were eligible to include in this review. Three out of five included studies that assessed the total size of the quadriceps and reported no significant differences between the PFP and healthy control group. Two out of five of the studies assessed the total size of the quadriceps between the symptomatic and asymptomatic limb of the PFP patients and reported the statistical difference between limbs. Only one study measured the fiber angle of the VMO muscle at the patella. Controversial results were found between studies that assessed the size of individual parts of the quadriceps.

CONCLUSION

Due to the controversial results of the included studies, this systematic review failed to draw a conclusion on the role of quadriceps atrophy in PFP pathology. The limitation in PFP literature considering pennation/fiber angle, echogenicity and fiber length of individual parts of the quadriceps muscle, rises the need for research that focuses on the biomechanical properties of the quadriceps in PFP patients.

Patellofemoral pain: One year results of a randomized trial comparing hip exercise, knee exercise, or free activity

OBJECTIVE

Extended follow-up of a randomized trial comparing hip-focused exercise, knee-focused exercise, and free physical activity in patellofemoral pain (PFP).

METHODS

A single-blind randomized controlled trial included 112 patients aged 16-40 years (mean 27.6 years) with a clinical diagnosis of PFP ≥3 months (mean 39 months) and pain ≥3/10 on a Visual Analog Scale. Patients were randomized to a 6-week exercise-based intervention consisting of either isolated hip-focused exercises (n = 39), traditional knee-focused exercise (n = 37), or free physical activity (n = 36). All patients received the same patient education. The primary outcome measure was the Anterior Knee Pain Scale (AKPS, 0-100). Secondary outcomes were usual and worst pain, Tampa Scale of Kinesiophobia, Knee Self-Efficacy Score, Euro-Qol (EQ-5D-5L), step-down test, and isometric strength. Blinded observers assessed outcomes at baseline, 3, and 12 months. The study was designed to detect a difference in AKPS >10 at 12 months.

RESULTS

After 1 year, there were no significant between-group differences in any primary or secondary outcomes. Between-group differences for AKPS were as follows: knee versus free physical activity -4.3 (95% CI -12.3 to 3.7); hip versus free physical activity -1.1 (95% CI -8.9 to 6.7); and hip versus Knee 3.2 (95% CI -4.6 to 11.0). The cohort as a whole improved significantly at 3 and 12 months compared to baseline for all measures except for knee extension strength.

CONCLUSION

After 1 year, there was no difference in effectiveness of knee exercise, hip exercise, or free physical activity, when combined with patient education in PFP.

Influence of body mass index on patellofemoral pain

Abstract Introduction: Patellofemoral Pain Syndrome is characterized by retro-patellar and peripatellar pain during squatting, kneeling and running whose intensity can be related to Body Mass Index (BMI). Objective: To evaluate the relationship between overweight, pain and function in women with Patellofemoral Pain Syndrome (PFPS). Method: Cross-sectional observational study of fifty-four women with PFPS assessed in the period between January and December 2015, in the physiotherapy outpatient clinic of a tertiary hospital in the city of São Paulo. To verify the variables of pain at rest, at effort and function, the Numerical Pain Rating Scale (NPRS) and the Kujala Anterior Knee Pain Scale (AKPS) were used. The participants were divided into two groups, according to the BMI categories defined by the World Health Organization (WHO): Group 1, composed of women with normal BMI (18-24.9 kg/m²), with 36 patients, and group 2 composed of overweight women (25-29.9 k/m²), with 18 patients. Comparison between groups of pain at rest and effort and AKPS were performed using Student's t-test and Mann-Witney with statistical significance p < 0,05. Results: There was no statistically significant difference between groups for the pain at rest and effort and for AKPS. Conclusion: BMI does not impact pain intensity and function in women with PFPS.

Patellofemoral Joint Loads during Running Immediately Changed by Shoes with Different Minimalist Indices: A Cross-sectional Study

Purpose: Given the high incidence of patellofemoral pain syndrome (PFPS) in runners, this study aimed to investigate the immediate effect of shoes with different minimalist indices (MI) on the mechanical loads of the patellofemoral joint. Methods: Fifteen healthy male rearfoot strike runners were recruited to complete overground running trials at 3.33 m/s (±5%) in two running shoe conditions (MI = 26% versus MI = 86%). The amount of ten Vicon infrared cameras (100 Hz) and two Kistler force plates (1000 Hz) were used to collect kinematic and ground reaction force (GRF) data simultaneously. Quadriceps strength, patellofemoral contact force, patellofemoral contact area, and patellofemoral contact stress were calculated. Results: No significant differences were observed in the impact force and the second peak of the vertical GRF between the two shoe conditions. Compared to wearing low-MI shoes, wearing high-MI shoes showed that the maximum flexion angle of the knee, the contact area of patellofemoral joint and the peak knee extension moment reduced significantly (p < 0.01), and the peak patellofemoral contact force and stress decreased significantly (p < 0.05). Conclusion: These findings suggest that wearing high-MI shoes significantly decreases the patellofemoral contact force and patellofemoral joint stress by reducing the moment of knee extension, thus effectively reducing the load of the patellofemoral joint during the stance phase of running and potentially lowering the risk of PFPS.

Quadriceps architecture in individuals with patellofemoral pain: a systematic review protocol

OBJECTIVE

The objective of this review is to identify differences in quadriceps architectural parameters between healthy individuals and those with patellofemoral pain (PFP).

INTRODUCTION

Patellofemoral pain is one of the most common causes of knee pain among physically active populations. Muscular imbalance may play an important role in patellar malalignment or patellar maltracking. A systematic review will clarify the possible architectural changes of quadriceps muscles in persons with PFP.

INCLUSION CRITERIA

Eligible observational studies will include individuals younger than 50 years who have been diagnosed with unilateral or bilateral PFP. The comparator will be the contralateral, asymptomatic limb of the individual with PFP or a healthy matched subject. Studies that include measurement of quadriceps muscle size as the primary outcome will be considered. Studies in which participants had coexisting pathology, a history of lower limb surgery or injury, or pain originating from other joints will be excluded.

METHODS

PubMed/MEDLINE (NLM), Scopus, Embase, Physiotherapy Evidence Database, Web of Science and CINAHL databases and multiple gray literature sources will be searched. Studies published since 1 January 1990 will be considered; there will be no language restriction. Retrieval of full-text studies, assessment of methodological quality and data extraction will be performed independently by two reviewers. If possible, meta-analyses will be performed, and a Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Summary of Findings presented.

Effectiveness of Isolated Hip Exercise, Knee Exercise, or Free Physical Activity for Patellofemoral Pain: A Randomized Controlled Trial

BACKGROUND

Exercise for patellofemoral pain (PFP) is traditionally knee focused, targeting quadriceps muscles. In recent years, hip-focused exercise has gained popularity. Patient education is likely an important factor but is underresearched.

PURPOSE

To compare 3 treatment methods for PFP, each combined with patient education: hip-focused exercise, knee-focused exercise, or free physical activity.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A single-blind randomized controlled trial was performed with 112 patients who were 16 to 40 years old (mean, 27.6 years) and had a symptom duration >3 months (mean, 39 months) with a clinical diagnosis of PFP and no radiograph or magnetic resonance evidence of other pathology. Patients were randomized to a 6-week intervention consisting of patient education combined with isolated hip-focused exercise (n = 39), traditional knee-focused exercise (n = 37), or free physical activity (n = 36). The primary outcome was Anterior Knee Pain Scale (0-100) at 3 months. Secondary outcomes were visual analog scale for pain, Tampa Scale for Kinesiophobia, Knee Self-efficacy Scale, EuroQol, step-down, and isometric strength.

RESULTS

There were no between-group differences in any primary or secondary outcomes at 3 months except for hip abduction strength and knee extension strength. Between-group differences at 3 months for Anterior Knee Pain Scale were as follows: knee versus control, 0.2 (95% CI, -5.5 to 6.0); hip versus control, 1.0 (95% CI, -4.6 to 6.6); and hip versus knee, 0.8 (95% CI, -4.8 to 6.4). The whole cohort of patients improved for all outcomes at 3 months except for knee extension strength.

CONCLUSION

The authors found no difference in short-term effectiveness in combining patient education with knee-focused exercise, hip-focused exercise, or free training for patients with PFP.

REGISTRATION

NCT02114294 (ClinicalTrials.gov identifier).

Prevalence of excessive lateral pressure syndrome in varus osteoarthritic candidates for high tibial osteotomy

BACKGROUND

This study aimed to determine the prevalence of excessive lateral pressure syndrome (ELPS) in potential candidates for high tibial osteotomy (HTO) using single-photon emission computed tomography-computed tomography (SPECT-CT). We also sought to identify risk factors related to the presence of ELPS.

METHODS

This retrospective study included 150 patients (216 knees) who were candidates for HTO from an initial screening of 3579 patients (7158 knees). There were 183 female and 33 male knees with a mean age of 58 years. The presence of ELPS was defined as a grade 3 uptake on the SPECT-CT at the lateral PF joint. To determine the risk factors related to the ELPS, multivariate regression analysis was performed with independent demographic and radiographic variables.

RESULTS

Increased uptake on the lateral side of the PF joints was detected in 120 knees (56% of total subjects). Of these, 34 (16%) knees presented with a grade 3 uptake, which indicated the presence of ELPS. No single risk factor had significant associations with the presence of ELPS.

CONCLUSIONS

A considerable number of the knees that were candidates for HTO had ELPS. Nonetheless, we did not find any risk factor related to the presence of ELPS. These results suggest that surgeons should be cautious when diagnosing concomitant ELPS despite acceptable radiographic findings from patellofemoral joints when performing HTO.

Investigation of the Relationship between Anterior Knee Pain and Chondromalacia Patellae and Patellofemoral Malalignment

Objective

The study aimed to investigate whether there is any association of anterior knee pain and knee function with chondromalacia stage and patellofemoral alignment in patients with anterior knee pain for over a month and with chondromalacia patellae (CMP) detected by magnetic resonance imaging (MRI).

Materials and Methods

We reviewed the medical records of 38 patients who underwent a knee MRI examination and were diagnosed with chondromalacia based on the MRI. Knee MRI images were evaluated by a radiologist for chondromalacia staging. Patients were divided into two groups as early stage (stage 1-2) and advanced stage (stage 3-4) chondromalacia. Patients' demographical data (age, sex, and occupation), clinical features, physical examination findings and patellofemoral pain severity scale, kujala patellofemoral scoring system, and functional index questionnaire scores were obtained from their medical records. Trochlear sulcus angle, sulcus depth, lateral patellofemoral angle, patellar translation, and Insall-Salvati index were measured using the MRI images.

Results

The mean patient age was higher in the advanced stage CMP group compared to the early stage CMP group (p=0.038). There was no statistically significant difference regarding other demographical data (p>0.05). MRI measurement parameters did not show difference between the groups (p>0.05). Patients in the advanced stage CMP group had higher patellofemoral pain severity score, lower kujala patellofemoral score, and lower functional index questionnaire score compared to the early stage CMP group. The differences were statistically significant (p=0.008, p=0.012, and p=0.026, respectively).

Conclusion

As chondromalacia stage advances, the symptom severity worsens and knee functions decline; however, MRI measurements do not show difference between early and advanced stage CMP patients.

Evaluation and management of knee pain in young athletes: overuse injuries of the knee

Recurrent or chronic activity related knee pain is common in young athletes. Numerous intrinsic conditions affecting the knee can cause such pain. In addition, knee pain can be referred pain from low back, hip or pelvic pathology. The most common cause of knee pain in young athletes is patellofemoral pain syndrome, or more appropriately termed idiopathic anterior knee pain. Although, numerous anatomical and biomechanical factors have been postulated to contribute the knee pain in young athletes, the most common underlying reason is overuse injury. In this paper, we have reviewed selected conditions that case knee pain in athletes, including anterior knee pain syndrome, Osgood-Schlatter disease, Sinding-Larsen-Johanssen syndrome, juvenile osteochondritis dissecans (JOCD), bipartite patella, plica syndrome, and tendonitis around the knee.

Cross-Cultural Adaptation and Psychometric Properties Testing of the Arabic Anterior Knee Pain Scale

Background

PFPS is one of the most frequently occurring overuse injuries affecting the lower limbs. A variety of functional and self-reported outcome measures have been used to assess clinical outcomes of patients with PFPS, however, only the Anterior Knee Pain Scale (AKPS) has been designed for PFPS patients.

Material/Methods

We followed international recommendations to perform a cross-cultural adaptation of the AKPS. The Arabic AKPS and the Arabic RAND 36-item Health Survey were administered to 40 patients who were diagnosed with PFPS. Participants were assessed at baseline and after 2 to 3 days assessed with the Arabic AKPS only. The measurements tested were reliability, validity, and feasibility.

Results

The Arabic AKPS showed high reliability for both temporal stability, internal consistency (Cronbach’s alpha was 0.81 for the first assessment and 0.75 for the second), excellent test-retest reliability (Intraclass Correlation Coefficients ICC=0.96; 95% confidence interval (CI): 0.93, 0.98) and good agreement (standard error of measurement SEM=1.8%). The Arabic AKPS was significantly correlated with physical components of the RAND 36-Item Health Survey (Spearman’s rho=0.69: p<0.001). No ceiling or floor effects were observed.

Conclusions

The Arabic AKPS is a valid and reliable tool and is comparable to the original English version and other translated versions.