Targeted physiotherapy for patellofemoral joint osteoarthritis: a protocol for a randomised, single-blind controlled trial

Unlocking the potential of exosomes: a breakthrough in the theranosis of degenerative orthopaedic diseases

Degenerative orthopaedic diseases pose a notable worldwide public health issue attributable to the global aging population. Conventional medical approaches, encompassing physical therapy, pharmaceutical interventions, and surgical methods, face obstacles in halting or reversing the degenerative process. In recent times, exosome-based therapy has gained widespread acceptance and popularity as an effective treatment for degenerative orthopaedic diseases. This therapeutic approach holds the potential for "cell-free" tissue regeneration. Exosomes, membranous vesicles resulting from the fusion of intracellular multivesicles with the cell membrane, are released into the extracellular matrix. Addressing challenges such as the rapid elimination of natural exosomes in vivo and the limitation of drug concentration can be effectively achieved through various strategies, including engineering modification, gene overexpression modification, and biomaterial binding. This review provides a concise overview of the source, classification, and preparation methods of exosomes, followed by an in-depth analysis of their functions and potential applications. Furthermore, the review explores various strategies for utilizing exosomes in the treatment of degenerative orthopaedic diseases, encompassing engineering modification, gene overexpression, and biomaterial binding. The primary objective is to provide a fresh viewpoint on the utilization of exosomes in addressing bone degenerative conditions and to support the practical application of exosomes in the theranosis of degenerative orthopaedic diseases.

The application of exosomes in the early diagnosis and treatment of osteoarthritis

With the increase in human lifespan and the aggravation of global aging, the incidence of osteoarthritis (OA) is increasing annually. To better manage and control the progression of OA, prompt diagnosis and treatment for early-stage OA are important. However, a sensitive diagnostic modality and therapy for early OA have not been well developed. The exosome is a class of extracellular vesicles containing bioactive substances, that can be delivered directly from original cells to neighboring cells to modulate cellular activities through intercellular communication. In recent years, exosomes have been considered important in the early diagnosis and treatment of OA. Synovial fluid exosome and its encapsulated substances, e.g., microRNA, lncRNA, and proteins, can not only distinguish OA stages but also prevent the progression of OA by directly targeting cartilage or indirectly modulating the immune microenvironment in the joints. In this mini-review, we include recent studies on the diagnostic and therapeutic modalities of exosomes and hope to provide a new direction for the early diagnosis and treatment of OA disease in the future.

The effect of transcranial direct stimulation as an add-on treatment to conventional physical therapy on pain intensity and functional ability in individuals with knee osteoarthritis: A randomized controlled trial

OBJECTIVE

To investigate the effect of adding transcranial direct current stimulation (tDCS) to conventional physiotherapy treatment (PT) on pain and performance of individuals with knee osteoarthritis (KOA).

METHODS

Eighty people suffering from chronic KOA participated in this study. They were randomly divided into four treatment groups, including PT combined with tDCS over the primary motor cortex (M1), PT combined with tDCS over the primary sensory cortex (S1), PT combined with tDCS over the dorsolateral prefrontal cortex (DLPFC), and PT combined with sham tDCS. A visual analog scale (VAS) for pain intensity, the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire for knee-related disability, and several performance tests (stepping 15 s, chair stand test in 30 s, and walking 4 × 10 m) were used for assessment following 10 sessions of tDCS (T1), and one month after the last session of tDCS (T2).

RESULTS

Differential effects on pain intensity, knee-related disability, and performance were found between groups. Compared to sham tDCS: (i) tDCS over M1 improved VAS pain score, KOOS disability score, and performance tests at T1 and T2; (ii) tDCS over S1 improved VAS pain score at T1 and T2 and KOOS disability score and performance tests at T2; (iii) tDCS over the DLPFC improved VAS pain score at T1 and performance tests at T1 and T2.

CONCLUSION

tDCS could be a beneficial add-on treatment to conventional PT for pain relief, disability reduction and functional improvement in patients with KOA.

Patellofemoral arthroplasty versus total knee arthroplasty for isolated patellofemoral osteoarthritis: a systematic review and meta-analysis

BACKGROUND

Isolated patellofemoral osteoarthritis (PF-OA) is a common subtype of knee osteoarthritis, leading to a huge economic burden on health care systems. Although previous studies have shown that patellofemoral arthroplasty (PFA) and total knee arthroplasty (TKA) have good clinical effects, it remains largely unclear which treatment is more effective for patients with isolated PF-OA. We aimed to compare postoperative function, complications, revision rates, level of physical activity, and satisfaction rate between the two surgical techniques.

METHODS

Our study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Search of literature was conducted in MEDLINE, EMBASE, Cochrane Library, and Web of Science until November 2020. The included studies were those that provided direct comparison of postoperative outcomes between PFA and TKA. Data were extracted from eligible studies and combined to calculate the pooled odds ratio (OR) and 95% confidence interval (CI). Sensitivity analysis and subgroup analysis were conducted to evaluate heterogeneity between the two groups.

RESULTS

A total of 7 eligible studies (3 recent randomized controlled trials and 4 nonrandomized controlled trials) were included in this meta-analysis. The pooled results showed that both the PFA group and the TKA group had improved postoperative indicators, suggesting that the two operation modes could improve the knee function and quality of life of patients. Throughout the first 2 years postoperatively, higher activity level, and better functional recovery were observed for PFA compared with TKA in this study; moreover, the differences between the two operation modes were statistically significant (p < 0.05). We found no significant difference in complications, revision rates, and satisfaction rate between the two procedures.

CONCLUSION

Although there was no observed difference in the complications, revision rates, and satisfaction rate between PFA and TKA, PFA was superior to TKA in terms of knee function and physical activity in the first 2 years postoperatively. Therefore, PFA is a safe, effective, and less invasive treatment for patients with isolated PF-OA. Our findings are consistent with the systematic review of current evidence that PFA may be more suitable for younger patients with high activity needs. Patient selection is, therefore, thought to be of paramount importance. Individualized surgical plan should be designed according to the patient's age, BMI, KOA site, and activity level and combined with the doctor's personal experience.

Squatting versus squatting with hip adduction in management of patellofemoral osteoarthritis: A randomized controlled trial

BACKGROUND

Patellofemoral osteoarthritis is a common presentation in the outpatients' physical therapy clinics. The muscle imbalance between the vastus medialis oblique and vastus lateralis muscles is one of the main factors that lead to the development of this condition.

OBJECTIVE

To compare the effect of a squatting versus squatting with hip adduction in management of patellofemoral osteoarthritis.

METHODS

Patients in group A received a traditional physical therapy program in addition to squatting exercise and those in group B received a traditional physical therapy program in addition to squatting with hip adduction exercise for four weeks. The primary outcome measures were pain on the numerical rating scale (NRS) and performance of functional activities by Kujala scale, while the secondary outcomes were vastus medialis oblique (VMO) and vastus lateralis (VL) amplitudes as well as the VMO:VL ratio by surface electromyography were considered before and after intervention.

RESULTS

Thirty patients (group A n= 15; group B n= 15) were randomized and analyzed. Comparing both groups post-program revealed that there was no significant difference between both groups regarding the vastus medialis oblique activity, VMO:VL ratio, pain intensity and performance of functional activities.

CONCLUSION

Both a traditional physical therapy program in addition to squatting exercise and a traditional physical therapy program in addition to squatting exercise with hip adduction are effective in reduction of pain intensity increases performance of functional activities, and vastus medialis oblique amplitude. However, there is no superiority of one program over the other.

Hip abductor muscle volumes are smaller in individuals affected by patellofemoral joint osteoarthritis

OBJECTIVE

The aims of this study were twofold: firstly, to compare hip abductor muscle volumes in individuals with patellofemoral joint (PFJ) osteoarthritis (PFJ OA) against those of healthy controls; and secondly, to determine whether hip muscle volumes and hip kinematics during walking are related in individuals with PFJ OA and healthy controls.

METHODS

Fifty-one individuals with PFJ OA and thirteen asymptomatic, age-matched healthy controls ≥40 years were recruited. Volumes of the gluteus medius, gluteus minimus and tensor fasciae latae were obtained from magnetic resonance (MR) images. Video motion capture was used to measure three-dimensional hip joint kinematics during overground walking.

RESULTS

Significantly smaller gluteus medius (P = 0.017), gluteus minimus (P = 0.001) and tensor fasciae latae (P = 0.027) muscle volumes were observed in PFJ OA participants compared to controls. Weak correlations were observed between smaller gluteus minimus volume and larger hip flexion angle at contralateral heel strike (CHS) (r = -0.279, P = 0.038) as well as between smaller gluteus minimus volume and increased hip adduction angle at CHS (r = -0.286, P = 0.046).

CONCLUSION

Reduced hip abductor muscle volume is a feature of PFJ OA and is associated with increased hip flexion and adduction angles during the late stance phase of walking for PFJ OA participants and healthy controls.

Patient-reported outcome measures (PROMs) in patients undergoing patellofemoral arthroplasty and total knee replacement: A comparative study

BACKGROUND

Incongruity in the evaluation of outcomes between patients and surgeons has led to an increasing utilization of patient-reported outcome measures (PROMs) as an evaluation method of outcome.

OBJECTIVE

The aim of this study was to compare Oxford Knee Score (OKS), KOOS-PS and Kujala Score results in patients who received either PFA or TKA with and without patella resurfacing in the tretament of knee osteoarthritis.

METHODS

A total of 50 patients (PFA = 19 patients; TKA with patelloplasty = 15 patients; TKA with patellar resurfacing = 16 patients) undergone surgery between 2011 and 2014 and were included for final analysis.

RESULTS

No statistical significance was found for OKS, KOOS-PS and Kujala scores between the three groups. However, although patients with PFA experienced higher levels of pain.

CONCLUSIONS

According to our results, it is essential to discuss the treatment options and quality of life expectations with the patient prior joint replacement surgery in order to reduce patient dissatisfaction.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

A 6-week hip muscle strengthening and lumbopelvic-hip core stabilization program to improve pain, function, and quality of life in persons with patellofemoral osteoarthritis: a feasibility pilot study

Background

Patellofemoral joint (PFJ) osteoarthritis (OA) is prevalent in middle-aged and older adults. Despite this, there are minimal studies which have examined conservative interventions for PFJ OA. Weakness of proximal lower extremity muscles is associated with PFJ OA. It is unknown if a hip muscle strengthening and lumbopelvic-hip core stabilization program will improve symptoms and function in persons with PFJ OA. This study examined the feasibility and impact of a 6-week hip muscle strengthening and core stabilization program on pain, symptoms, physical performance, peak muscle torques, and quality of life in persons with PFJ OA.

Methods

Ten females with PFJ OA and ten age- and sex-matched controls participated in baseline tests. PFJ OA participants attended ten twice-a-week hip strengthening and core stabilization exercise sessions. Outcome measures included questionnaires, the Timed-Up-and-Go, and peak isometric torque of hip and quadriceps muscles. Data were tested for normality; parametric and non-parametric tests were used as appropriate.

Results

At baseline, the PFJ OA group had significantly worse symptoms, slower Timed-Up-and-Go performance, and lower muscle torques than control participants. PFJ OA group adherence to supervised exercise sessions was adequate. All PFJ OA participants attended at least nine exercise sessions. Five PFJ OA participants returned 6-month follow-up questionnaires, which was considered fair retention. The PFJ OA participants' self-reported pain, symptoms, function in daily living, function in sport, and quality of life all improved at 6 weeks (P < 0.05). Timed-Up-and-Go time score improved at 6 weeks (P = 0.005). Peak hip external rotator torque increased (P = 0.01). Improvements in pain and self-reported function were no longer significant 6 months following completion of the intervention.

Conclusions

PFJ OA participants were adherent to the supervised sessions of the intervention. Improvement in symptoms, physical performance, and muscle torque were found after 6 weeks. Participant retention at 6 months was fair, and significant changes were no longer present. Our findings suggest that a hip strengthening and core stabilization program may be beneficial to improve symptoms, function, and physical performance in persons with PFJ OA. Future studies are needed, and additional measures should be taken to improve long-term adherence to exercise.

Trial registration

ClinicalTrials.gov NCT02825238. Registered 6 July 2016 (retrospectively registered).

A pilot randomised clinical trial of physiotherapy (manual therapy, exercise, and education) for early-onset hip osteoarthritis post-hip arthroscopy

Background

Despite the increasing use of hip arthroscopy for hip pain, there is no level 1 evidence to support physiotherapy rehabilitation programs following this procedure. The aims of this study were to determine (i) what is the feasibility of a randomised controlled trial (RCT) investigating a targeted physiotherapy intervention for early-onset hip osteoarthritis (OA) post-hip arthroscopy? and (ii) what are the within-group treatment effects of the physiotherapy intervention and a health-education control group?

Methods

This study was a pilot single-blind RCT conducted in a private physiotherapy clinic in Hobart, Australia. Patients included 17 volunteers (nine women; age 32 ± 8 years; body mass index = 25.6 ± 5.1 kg/m²) who were recruited 4–14 months post-hip arthroscopy, with chondropathy and/or labral pathology at the time of surgery. Interventions included a physiotherapy treatment program that was semi-standardised and consisted of (i) manual therapy; (ii) hip strengthening and functional retraining; and (iii) health education. Control treatment encompassed individualised health education sessions. The primary outcome measure was feasibility, which was reported as percentage of eligible participants enrolled, adherence with the intervention, and losses to follow-up. The research process was evaluated using interviews, and an estimated sample size for a definitive study is offered. Secondary outcomes included the Hip disability and Osteoarthritis Outcome Score (HOOS) and the International Hip Outcome Tool (IHOT-33) patient-reported outcomes.

Results

Seventeen out of 48 eligible patients (35%) were randomised. Adherence to the intervention was 100%, with no losses to follow-up. The estimated sample size for a full-scale RCT was 142 patients. The within-group (95% confidence intervals) change scores for the physiotherapy group were HOOS-Symptoms 6 points (−4 to 16); HOOS-Pain 10 points (−2 to 22); HOOS-Activity of Daily Living 8 points (0 to 16); HOOS-Sport 3 points (−12 to 19); HOOS-Quality of Life 3 points (−7 to 13); and IHOT-33 7 points (−10 to 25). The within-group (95% confidence intervals) change scores for the control group were HOOS-Symptoms −4 points (−17 to 9); HOOS-Pain −2 points (−18 to 13); HOOS-Activity of Daily Living −7 points (−17 to 4); HOOS-Sport 4 points (−16 to 23); HOOS-Quality of Life −5 points (−18 to 9); and IHOT-33 −4 points (−27 to 19). Suggestions to improve study design included greater supervision of exercises and increased access to physiotherapy appointments.

Conclusions

Results support the feasibility of a full-scale RCT, and recommendations for an adequately powered and improved study to determine the efficacy of this physiotherapy intervention post-hip arthroscopy to reduce pain and improve function are provided.

Trial registration

Australian Clinical Trials Registry, ACTRN12614000426684

Patients With Chondrolabral Pathology Have Bilateral Functional Impairments 12 to 24 Months After Unilateral Hip Arthroscopy: A Cross-sectional Study

Study Design Cross-sectional study. Background Functional task performance in patients with chondrolabral pathology following hip arthroscopy is unknown. Objectives To investigate in people with chondrolabral pathology following hip arthroscopy (1) the bilateral differences in functional task performance compared to controls, (2) the association of hip muscle strength with functional task performance, and (3) the association of functional task performance scores with good outcome, as measured by International Hip Outcome Tool score. Methods Seventy-one patients who had unilateral hip arthroscopy for hip pain and 60 controls were recruited. Patient-reported outcomes included the 4 subscales of the International Hip Outcome Tool. Hip muscle strength measures included abduction, adduction, extension, flexion, external rotation, and internal rotation. Functional tasks assessed included the single hop test, the side bridge test, and the single-leg rise test. For aim 1, analyses of covariance tests were used. For aim 2, stepwise multiple linear regression analyses were used. For aim 3, receiver operating characteristic curve analyses were used. Results Compared to controls, the chondrolabral pathology group had significantly worse performance on both legs for each of the functional tasks (P<.001). Greater hip abduction strength was moderately associated with better performance on functional tasks in the chondrolabral pathology group (adjusted R² range, 0.197-0.407; P<.001). Cutoff values associated with good outcome were 0.37 (hop distance/height) for the single hop, 16 repetitions for the single-leg rise, and 34 seconds for the side bridge test. Conclusion Patients with hip chondrolabral pathology had reduced functional task performance bilaterally 12 to 24 months after unilateral hip arthroscopy when compared to controls. Level of Evidence Therapy/symptom prevalence, level 3b. J Orthop Sports Phys Ther 2016;46(11):947-956. doi:10.2519/jospt.2016.6577.

Changes in patellofemoral and tibiofemoral joint cartilage damage and bone marrow lesions over 7 years: the Multicenter Osteoarthritis Study

OBJECTIVES

To investigate changes in cartilage damage and bone marrow lesions (BMLs) on MRI in the patellofemoral and tibiofemoral joints (TFJs) over 7 years.

METHODS

The Multicenter Osteoarthritis (MOST) Study is a cohort study of persons aged 50-79 years at baseline with or at high risk for knee osteoarthritis (OA). Knees were eligible for the current study if they had knee MRI (1.0T) assessed for cartilage damage and BMLs at the baseline and 84-month visits. Knees were categorized as having MRI-detected structural damage (cartilage and BMLs) isolated to the patellofemoral joint (PFJ), isolated to the TFJ, mixed or no damage at baseline and 84-months. We determined the changes in PFJ and TFJ structural damage over 7 years and used logistic regression to assess the relation of baseline compartment distribution to incident isolated PFJ, isolated TFJ and mixed damage.

RESULTS

Among 339 knees that had full-thickness cartilage loss isolated to the PFJ or TFJ at baseline, only 68 (20.1%) developed full-thickness cartilage loss in the other compartment while 271 (79.9%) continued to only have the initial compartment affected. Compared to knees without full-thickness cartilage damage (n = 582), those with isolated TFJ and PFJ full-thickness cartilage damage had 2.7 (1.5, 4.9) and 5.8 (3.6, 9.6) times the odds of incident mixed full-thickness cartilage damage, respectively. Similar results were seen when using other definitions of MRI-defined structural damage.

CONCLUSIONS

Most knees with structural damage at baseline do not develop it in the other compartment. Knees that develop mixed structural damage are more likely to start with it isolated to the PFJ.

Effect of exercise therapy on neuromuscular activity and knee strength in female adolescents with patellofemoral pain-An ancillary analysis of a cluster randomized trial

BACKGROUND

Female adolescents with patellofemoral pain are characterized by altered neuromuscular knee control and reduced maximal quadriceps torque. The purpose of this study is to investigate whether exercise therapy and patient education are associated with larger improvements in neuromuscular knee control and maximal quadriceps torque compared with patient education alone.

METHODS

This is an ancillary analysis of a cluster randomized controlled trial investigating the effect of patient education and exercise therapy on self-reported recovery in 121 adolescents with patellofemoral pain. A random subsample of 57 female adolescents was included and tested at baseline and after 3months. Neuromuscular control of the knee was quantified as the complexity of surface electromyography of the vastus lateralis and vastus medialis during stair descent. Secondary outcomes were complexity of knee flexion/extension kinematics and maximal quadriceps torque.

FINDINGS

There was an 8-15% greater decrease in the complexity of surface electromyography suggesting an improvement in neuromuscular knee control among those randomized to exercise therapy (0.08<p<0.30). Adolescents randomized to exercise therapy had a 0.28-Nm/kg (95% CI: 0.05-0.52; p=0.02) larger increase in maximal quadriceps torque.

INTERPRETATION

Female adolescents randomized to patient education and exercise therapy had a significantly larger increase in maximal quadriceps torque and greater improvement in neuromuscular knee control during stair descent than those receiving patient education alone. This suggest that exercise therapy has an effect not only on self-reported outcome measures but also on objective measures of thigh muscle function in female adolescents with patellofemoral pain.

Exercise, education, manual-therapy and taping compared to education for patellofemoral osteoarthritis: a blinded, randomised clinical trial

OBJECTIVE

Patellofemoral joint osteoarthritis (PFJ OA) contributes considerably to knee OA symptoms. This study aimed to determine the efficacy of a PFJ-targeted exercise, education manual-therapy and taping program compared to OA education alone, in participants with PFJ OA.

METHODS

A randomised, participant-blinded and assessor-blinded clinical trial was conducted in primary-care physiotherapy. 92 people aged ≥40 years with symptomatic and radiographic PFJ OA participated. Physiotherapists delivered the PFJ-targeted exercise, education, manual-therapy and taping program, or the OA-education (control condition) in eight sessions over 12 weeks. Primary outcomes at 3-month (primary) and 9-month follow-up: (1) patient-perceived global rating of change (2) pain visual analogue scale (VAS) (100 mm); and (3) activities of daily living (ADL) subscale of the Knee injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

81 people (88%) completed the 3-month follow-up and data analysed on an intention-to-treat basis. Between-group baseline similarity for participant characteristics was observed. The exercise, education, manual-therapy and taping program resulted in more people reporting much improvement (20/44) than the OA-education group (5/48) (number needed to treat 3 (95% confidence interval (CI) 2 to 5)) and greater pain reduction (mean difference: -15.2 mm, 95% CI -27.0 to -3.4). No significant effects on ADL were observed (5.8; 95% CI -0.6 to 12.1). At 9 months there were no significant effects for self-report of improvement, pain (-10.5 mm, 95% CI -22.7 to 1.8) or ADL (3.0, 95% CI -3.7 to 9.7).

CONCLUSION

Exercise, education, manual-therapy and taping can be recommended to improve short-term patient rating of change and pain severity. However over 9-months, both options were equivalent.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ACTRN12608000288325): https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=82878.

The relation of MRI-detected structural damage in the medial and lateral patellofemoral joint to knee pain: the Multicenter and Framingham Osteoarthritis Studies

OBJECTIVE

To examine the relation of cartilage loss and bone marrow lesions (BMLs) in the medial and lateral patellofemoral joint (PFJ) to knee pain.

METHODS

We categorized the location of full-thickness cartilage loss and BMLs in the PFJ on knee magnetic resonance imaging (MRIs) from the Multicenter Osteoarthritis (MOST) and Framingham Osteoarthritis (FOA) Studies as no damage, isolated medial, isolated lateral, or both medial and lateral (mixed). We determined the relation of MRI lesions in each PFJ region to prevalent knee pain. Differences in knee pain severity were compared among categories of PFJ full-thickness cartilage loss and BMLs using quantile regression.

RESULTS

In MOST (n = 1137 knees), compared with knees without full-thickness cartilage loss, knees with isolated lateral or mixed PFJ full-thickness cartilage loss had 1.9 (1.3, 2.8) and 1.9 (1.2, 2.9) times the odds of knee pain, respectively, while isolated medial cartilage loss had no association with knee pain. BMLs in both the medial and lateral PFJ had 1.5 (1.1, 2.0) times the odds of knee pain compared with knees without BMLs. Knee pain severity was lowest in knees with isolated medial PFJ cartilage loss or BMLs. In FOA (n = 934 knees), neither isolated medial nor lateral cartilage loss was associated with knee pain, whereas isolated BMLs in either region were associated with pain.

CONCLUSIONS

Results were not completely concordant but suggest that knee pain risk and severity is greatest with cartilage loss isolated to (MOST) or inclusive of (MOST and FOA) the lateral PFJ. While BMLs in either the medial or lateral PFJ are related to pain.

Is patellofemoral osteoarthritis common in middle-aged people with chronic patellofemoral pain?

OBJECTIVE

To document the prevalence of radiographic osteoarthritis (OA) in the medial and lateral patellofemoral (PF) joint compartments relative to the prevalence of tibiofemoral (TF) joint OA in middle-aged and older adults with chronic PF knee pain.

METHODS

A convenience sample of 224 people who volunteered for a clinical trial underwent weight-bearing posteroanterior and skyline knee radiographs of their most symptomatic eligible knee. Radiographic severity in the TF joint and in the medial and lateral PF joint compartments was independently graded by 2 examiners using the Kellgren/Lawrence (K/L) grading system. K/L grades ≥2 were considered evidence of OA.

RESULTS

OA was common in this cohort, and the most prevalent pattern was combined TF joint and PF joint OA (n = 98 [44%]), followed by isolated PF joint OA (n = 57 [25%]). Isolated TF joint OA was rare. Overall, more people demonstrated radiographic OA in the PF joint (n = 155 [69%]) than in the TF joint (n = 100 [45%]). The majority of people with PF joint OA had OA in both the medial and lateral PF joint compartments (n = 98 [63%]). Even in people ages <50 years, radiographic OA was common (isolated PF joint OA, 26% [n = 21]; combined TF joint and PF joint OA, 29% [n = 23]). The severity of PF joint OA was similar across men and women.

CONCLUSION

PF joint OA was highly prevalent, more so than TF joint OA, and even in individuals ages <50 years. Further research is needed to elucidate the cause and effect relationship between chronic PF pain and PF joint OA.

Patellofemoral joint osteoarthritis: an individualised pathomechanical approach to management

Patellofemoral joint integrity is maintained by an optimal interaction of passive, dynamic and structural restraints. Disruption of these mechanics can lead to structural joint damage and subsequent patellofemoral osteoarthritis, which is a prevalent and disabling condition with few effective conservative management strategies. Due to the influential role of biomechanics in this disease, targeting the specific pathomechanics exhibited by an individual is logical to improve their likelihood of a positive treatment outcome. This review summarises the effect of different pathomechanical factors on the presence and progression of patellofemoral osteoarthritis. It then presents a synthesis of mechanical effect of treatment strategies specifically addressing these pathomechanics. Identifying the pathomechanics and clinical characteristics of individuals with patellofemoral osteoarthritis that respond to treatment may assist in the development of individualised treatment strategies that alleviate symptoms and slow structural damage.

Crepitus is a first indication of patellofemoral osteoarthritis (and not of tibiofemoral osteoarthritis)

OBJECTIVE

The patellofemoral joint (PFJ) is important in early detection of knee osteoarthritis (OA). Little is known about the relationship between specific clinical findings and PFJ Magnetic resonance Imaging (MRI) features. The objective was to examine the relationship between (early) clinical findings and PFJ MRI features in females (45-60 years) without knee OA (PFJ or tibiofemoral joint (TFJ) OA) based on a recently suggested MRI definition.

METHODS

MRIs of knees of women of a sub-study of the Rotterdam Study were scored with semi-quantitative scoring. Specific patellar tests were performed on physical examination. Current knee pain and history of patellar knee pain were reported. Binomial logistic generalized estimated equations were used to determine the association between clinical findings of OA and PFJ MRI features. All associations were adjusted for age, body mass index (BMI) and TFJ MRI features.

RESULTS

In 888 women (1776 knees, mean age: 55.1 years and mean BMI: 27.0 kg/m(2)) we found significant associations between crepitus and all PFJ MRI features (Odds ratios (OR) range: 2.61-5.49). A history of patellar pain was significantly associated with almost all PFJ MRI features (ORcartilage: 1.95; ORcysts: 1.86; ORbone marrow lesions: 1.83), except for osteophytes. No significant associations were found between the clinical findings and TFJ MRI features.

CONCLUSION

Crepitus and history of patellar pain are clinical findings that indicate PFJ lesions seen on MRI. These tests could help to indicate signs of PFJOA. Follow-up data needs to confirm whether these tests have an additional diagnostic value for early knee OA in PFJ or TFJ.

Exercícios físicos e osteoartrose: uma revisão sistemática

INTRODUÇÃO: A osteoartrose (OA) é uma doença articular crônico-degenerativa que se evidencia pelo desgaste da cartilagem articular e que atinge frequentemente as articulações que sustentam peso, como o joelho. OBJETIVO: Relatar as principais evidências associadas ao uso do exercício físico na melhora dos sintomas decorrentes da osteoartrose em indivíduos acima de 50 anos. MATERIAIS E MÉTODOS: Trata-se de uma revisão sistemática de literatura, com a utilização das bases de dados eletrônicos de periódicos indexados: National Library of Medicine (MEDLINE - PubMed), Literatura Latino-Americana e do Caribe em Ciência da Saúde (LILACS), e a base Scientific Electronic Library Online (SciELO). RESULTADOS: Foram encontrados 1.405 artigos, selecionados nas bases de dados SciELO, LILACS, PubMed e MEDLINE; destes, 101 artigos foram selecionados. Entre as regiões acometidas pela osteoartrose, o joelho foi o local mais mencionado, seguido do joelho e quadril juntos; outras regiões foram citadas com menor recorrência. Os exercícios que tiveram maior destaque foram exercícios aquáticos, isocinéticos, treinamento de força muscular, caminhada, além da educação em saúde que também foi muito utilizada nos estudos selecionados. CONCLUSÃO: Pôde-se constatar por esta revisão que os estudos demonstram a eficácia do uso de exercícios na melhora dos sintomas decorrentes da osteoartrose, porém, não há um consenso quanto aos parâmetros de aplicação, como intensidade e duração de cada tipo de exercício.

Gait biomechanics and hip muscular strength in patients with patellofemoral osteoarthritis

A significant number of patients with patellofemoral osteoarthritis (PFOA) have described a history of patellofemoral pain syndrome (PFPS). This leads to speculation that the underpinning mechanical causes of PFPS and PFOA may be similar. Although alterations in gait biomechanics and hip strength have been reported in PFPS, this relationship has not yet been explored in PFOA. Therefore the purpose of this study was compare gait biomechanics and hip muscular strength between PFOA patients and a healthy control group. Fifteen patients with symptomatic, radiographic PFOA and 15 controls participated. All patients underwent a walking gait analysis and maximal hip strength testing. Biomechanical variables of interest included the peak angular values of contra-lateral pelvic drop, hip adduction and hip internal rotation during the stance phase. Hip abduction and external rotation strength were assessed using maximal voluntary isometric contractions. The PFOA group demonstrated significantly lower hip abduction strength compared to controls but no difference in hip external rotation strength. There were no statistical differences between the PFOA and control groups for contra-lateral pelvic drop, hip adduction and hip internal rotation angles during walking. Despite patients with PFOA exhibiting weaker hip abductor muscle strength compared to their healthy counterparts they did not demonstrate alterations in pelvis or hip biomechanics during gait. These preliminary data suggests that weaker hip abductor strength does not result in biomechanical alterations during gait in this population.

Altered hip muscle forces during gait in people with patellofemoral osteoarthritis

OBJECTIVES

The study aimed to (1) assess whether higher vasti (VASTI), gluteus medius (GMED), gluteus maximus (GMAX) and gluteus minimus (GMIN) forces are associated with participant characteristics (lower age, male gender) and clinical characteristics (lower radiographic disease severity, lower symptom severity and higher walking speed); and (2) determine whether hip and knee muscle forces are lower in people with patellofemoral joint (PFJ) osteoarthritis (OA) compared to those without PFJ OA.

DESIGN

Sixty participants with PFJ OA and 18 (asymptomatic, no radiographic OA) controls ≥40 years were recruited from the community or via referrals. A three-dimensional musculoskeletal model was used in conjunction with optimisation theory to calculate lower-limb muscle forces during walking. Associations of peak muscle forces with participant and clinical characteristics were conducted using Pearson's r or independent t-tests and between-group comparisons of mean peak muscle forces performed with walking speed as a covariate.

RESULTS

Peak muscle forces were not significantly associated with participant, symptomatic or radiographic-specific characteristics. Faster walking speed was associated with higher VASTI muscle force in the PFJ OA (r = 0.495; P < 0.001) and control groups (r = 0.727; P = 0.001) and higher GMAX muscle force (r = 0.593; P = 0.009) in the control group only. Individuals with PFJ OA (N = 60) walked with lower GMED and GMIN muscle forces than controls (N = 18): GMED, mean difference 0.15 [95% confidence interval (CI): 0.01 to 0.29] body weight (BW); GMIN, 0.03 [0.01 to 0.06] BW. No between-group differences were observed in VASTI or GMAX muscle force: VASTI, 0.10 [-0.11 to 0.31] BW; GMAX, 0.01 [-0.11 to 0.09] BW.

CONCLUSION

Individuals with PFJ OA ambulate with lower peak hip abductor muscle forces than their healthy counterparts.

Patellofemoral joint compression forces in backward and forward running

Patellofemoral pain (PFP) is a common injury and increased patellofemoral joint compression forces (PFJCF) may aggravate symptoms. Backward running (BR) has been suggested for exercise with reduced PFJCF.

The aims of this study were to (1) investigate if BR had reduced peak PFJCF compared to forward running (FR) at the same speed, and (2) if PFJCF was reduced in BR, to investigate which biomechanical parameters explained this. It was hypothesized that (1) PFJCF would be lower in BR, and (2) that this would coincide with a reduced peak knee moment caused by altered ground reaction forces (GRFs).

Twenty healthy subjects ran in forward and backward directions at consistent speed. Kinematic and ground reaction force data were collected; inverse dynamic and PFJCF analyses were performed.

PFJCF were higher in FR than BR (4.5±1.5; 3.4±1.4BW; p<0.01). The majority of this difference (93.1%) was predicted by increased knee moments in FR compared to BR (157±54; 124±51 Nm; p<0.01). 54.8% of differences in knee moments could be predicted by the magnitude of the GRF (2.3±0.3; 2.4±0.2BW), knee flexion angle (44±6; 41±7) and center of pressure location on the foot (25±11; 12±6%) at time of peak knee moment. Results were not consistent in all subjects.

It was concluded that BR had reduced PFJCF compared to FR. This was caused by an increased knee moment, due to differences in magnitude and location of the GRF vector relative to the knee. BR can therefore be used to exercise with decreased PFJCF.

Early intervention for adolescents with patellofemoral pain syndrome--a pragmatic cluster randomised controlled trial

Background

Self-reported knee pain is highly prevalent among adolescents. As much as 50% of the non-specific knee pain may be attributed to Patellofemoral Pain Syndrome (PFPS). In the short term, exercise therapy appears to have a better effect than patient education consisting of written information and general advice on exercise or compared with placebo treatment. But the long-term effect of exercise therapy compared with patient education is conflicting. The purpose of this study is to examine the short- and long-term effectiveness of patient education compared with patient education and multimodal physiotherapy applied at a very early stage of the condition among adolescents.

Methods/Design

This study is a single blind pragmatic cluster randomised controlled trial. Four upper secondary schools have been invited to participate in the study (approximately 2500 students, aged 15-19 years). Students are asked to answer an online questionnaire regarding musculoskeletal pain. The students who report knee pain are contacted by telephone and offered a clinical examination by a rheumatologist. Subjects who fit the inclusion criteria and are diagnosed with PFPS are invited to participate in the study. A minimum of 102 students with PFPS are then cluster-randomised into two intervention groups based on which school they attend. Both intervention groups receive written information and education. In addition to patient education, one group receives multimodal physiotherapy consisting primarily of neuromuscular training of the muscles around the foot, knee and hip and home exercises.

The students with PFPS fill out self-reported questionnaires at baseline, 3, 6, 12 and 24 months after inclusion in the study. The primary outcome measure is perception of recovery measured on a 7-point Likert scale ranging from "completely recovered" to "worse than ever" at 12 months.

Discussion

This study is designed to investigate the effectiveness of patient education compared with patient education combined with multimodal physiotherapy. If patient education and multimodal physiotherapy applied at an early stage of Patellofemoral Pain Syndrome proves effective, it may serve as a basis for optimising the clinical pathway for those suffering from the condition, where specific emphasis can be placed on early diagnosis and early treatment.

Trial Registration

clinicaltrials.gov reference: NCT01438762

Anterior knee pain in younger adults as a precursor to subsequent patellofemoral osteoarthritis: a systematic review

BACKGROUND

Patellofemoral osteoarthritis (PFOA) is a common form of knee OA in middle and older age, but its relation to PF disorders and symptoms earlier in life is unclear. Our aim was to conduct a systematic review to investigate the strength of evidence for an association between anterior knee pain (AKP) in younger adults and subsequent PFOA.

METHODS

The search strategy included electronic databases (Pubmed, EMBASE, AMED, CINAHL, Cochrane, PEDro, SportDiscus: inception to December 2009), reference lists of potentially eligible studies and selected reviews. Full text articles in any language, - identified via English titles and abstracts, were included if they were retrospective or prospective in design and contained quantitative data regarding structural changes indicative of PFOA, incident to original idiopathic AKP. Eligibility criteria were applied to titles, abstracts and full-texts by two independent reviewers. Data extraction included study location, design, date, sampling procedure, sample characteristics, AKP/PFOA definitions, follow-up duration and rate, and main findings. Foreign language articles were translated into English prior to examination.

RESULTS

Seven articles satisfied eligibility (5 English, 2 German). Only one case-control study directly investigated a link between PFOA and prior AKP, providing level 3b evidence in favour of an association (OR 4.4; 95%CI 1.8, 10.6). Rough estimates of the annual risk of PFOA from the remaining six small, uncontrolled, observational studies (mean follow-up range: 5.7 to 23 years) ranged from 0% to 3.4%. This was not the primary aim of these studies, and limitations in design and methodology mean this data should be interpreted with caution.

CONCLUSIONS

There is a paucity of high-quality evidence reporting a link between AKP and PFOA. Further, well-designed cohort studies may be able to fill this evidence gap.

Exercise for people with hip or knee osteoarthritis: a comparison of land-based and aquatic interventions

Expert opinion considers the referral of people with osteoarthritis (OA) for physiotherapy to be a core component of managing the functional disability and pain of the disease. Clinical guidelines for the physiotherapy management of people with OA focus on three main areas: exercise, pain relief, and specific manual therapy techniques. Land-based group and individual physiotherapy exercise programs, as well as manual therapy, have demonstrated a distinct benefit in favor of physiotherapy intervention. Similarly, both general and specific aquatic physiotherapy exercise programs have shown positive outcomes for people with OA. This review will focus primarily on therapeutic exercise to improve strength and fitness and reduce pain in people with hip or knee OA. An overview of the principles of hydrodynamics relevant to aquatic exercise is also included to facilitate an understanding of effective aquatic exercise programs. The issue of compliance with exercise programs will also be discussed. Clinicians will, therefore, gain an understanding of the benefits of land-based and aquatic exercise for people with OA.

Quantifying the association of radiographic osteoarthritis in knee or hip joints with other knees or hips: the Johnston County Osteoarthritis Project

OBJECTIVE

To quantify the association of radiographic osteoarthritis (ROA) in one knee or hip joint with other knee or hip joints.

METHODS

We analyzed baseline data from the Johnston County Osteoarthritis Project (n = 3068). We fit 4 models for left/right knee/hip. The Kellgren-Lawrence (KL) radiographic grade severity scale was KL 0/1 (no/questionable ROA), 2 (mild ROA), or 3/4 (moderate/severe ROA). We estimated associations between KL grade in contralateral joints and other joint sites (e.g., worst hip in knee models), adjusting for sex, race/ethnicity (African American/white), age, and measured body mass index, using cumulative odds logistic regression models. Interactions were investigated: race/ethnicity by sex; race/ethnicity and sex by the 2 explanatory variables.

RESULTS

Contralateral joint KL grade was strongly associated with KL grade, with OR ranging from 9.2 (95% CI 7.1, 11.9) to 225.0 (95% CI 83.6, 605.7). In the left knee model, the contralateral joint association was stronger among African Americans than whites, but for the other models the associations by race/ethnicity were identical. Models examining other joint sites showed weaker but mostly statistically significant associations (OR 1.4 to 1.8).

CONCLUSION

We found a strong multivariable-adjusted association between KL grades in contralateral knees and hips, and a modest association with the other joint site (e.g., knees vs hips). These results suggest that diagnosis of ROA in 1 large joint may be a marker for risk of multijoint ROA, and warrant interventions to reduce the incidence or severity of ROA at these other joints.

Does isolated patellofemoral osteoarthritis matter?

OBJECTIVES

To describe the structure-pain and structure-function associations in isolated patellofemoral osteoarthritis (PF OA).

DESIGN

Population-based study of 819 adults aged > or =50 years with knee pain. The severity of knee pain, stiffness and disability were measured using the Western Ontario and McMaster Osteoarthritis Index (WOMAC). Three radiographic views of the knee were obtained.

RESULTS

Isolated PF OA was mild in 142 participants and moderate/severe in 44. Mean WOMAC scores for pain, stiffness and function were associated with radiographic severity of PF OA (F(2,389)=4.7, P=0.01; F(2,392)=4.5, P=0.012 and F(2,392)=6.1, P=0.002, respectively, adjusted for age, gender, and body mass index (BMI)). Post-hoc tests demonstrated statistically significant differences for mean pain, stiffness and function score between those with mild PF OA and those with normal X-rays. In task-specific items there was evidence of a stepped response, the proportion of participants with moderate/severe/extreme pain or difficulty in performing everyday tasks increasing with the severity of PF OA. The strongest association was observed for pain going up and down stairs (age-gender-BMI adjusted odds ratio (OR) 3.0; 95% confidence interval (CI) 1.4,6.6. Functional tasks most strongly related to radiographic severity were: descending stairs (OR 3.2; (CI 1.5,6.5)), getting in/out of the bath (3.2; 1.5,6.6), getting in/out of a car (3.0; 1.4,6.1).

CONCLUSIONS

Mild isolated PF OA is significantly associated with symptoms of pain, stiffness and functional limitation. Further research on its recognition in clinical practice and the development of targeted treatments to prevent or slow progression are warranted.