Four Outcome Measures for Patellofemoral Joint Problems

Examining the diagnostic accuracy of common physical examination and functional tests in the diagnosis of patellofemoral pain syndrome among patients with anterior knee pain

PURPOSE

The aims of this study were to evaluate the diagnostic accuracy of common physical examination and functional evaluation tests, and to determine a set of tests with the highest diagnostic accuracy for diagnosing patellofemoral pain syndrome (PFPS) in patients with anterior knee pain.

METHODS

Based on careful evaluation of clinical findings and imaging methods by orthopedic physicians, 162 patients with anterior knee pain were classified into two groups of PFPS and non-PFPS. The physical examination and functional tests were performed by two physiotherapists. The accuracy of these measures was determined by calculating sensitivity, specificity, area under the receiver operating characteristic (ROC) curve (AUC), likelihood ratio (LR), and predictive value (PV).

RESULTS

Our results showed the most sensitive tests in identifying patients with PFPS were as follows: eccentric step test [0.82 (95%CI: 0.72-0.89)]; palpation test [0.81(95%CI: 0.70-0.88)]; and prolonged sitting [0.73 (95%CI: 0.62-0.82)]. The palpation test, patellar tilt test, eccentric step test, navicular drop test, squatting, and stair descending tests had an acceptable accuracy (AUC ≥ 70). The strongest combination of the physical examination and functional tests included pain severity between 3 and 10 during stair descending test and pain severity between 6 and 10 during prolonged sitting test. This combination showed a positive LR of 19.47 (95% CI: 6.36-59.65) and a posttest probability of 95%.

CONCLUSION

Our findings provide evidence for the good accuracy of the palpation test, patellar tilt test, eccentric step test, navicular drop test, squatting, and stair descending and prolonged sitting tests for diagnosing PFPS. Also, the combination of stair descending test and prolonged sitting test could be very useful for ruling in PFPS patients.

Patient-Reported Outcome Measures for Adults and Adolescents With Patellofemoral Pain: A Systematic Review of Construct Validity, Reliability, Responsiveness, and Interpretability Using the COSMIN Methodology

OBJECTIVE: We aimed to appraise the construct validity, reliability, responsiveness, and interpretability of patient-reported outcome measures (PROMs) used to assess function and pain in adults and adolescents with patellofemoral pain (PFP). DESIGN: Systematic review of measurement properties LITERATURE SEARCH: We searched the PubMed, CINAHL, Scopus, SPORTDiscus, and Cochrane Library databases from inception to January 6, 2022. STUDY SELECTION CRITERIA: We included studies that assessed the measurement properties of English-language PROMs for PFP and their cultural adaptations and translations. DATA SYNTHESIS: Using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology, we determined overall ratings and quality of evidence for construct validity, internal consistency, reliability, measurement error, and responsiveness. We extracted data related to interpretability for clinical use. RESULTS: After screening 7066 titles, 61 studies for 33 PROMs were included. Only 2 PROMs had evidence of "sufficient" or "indeterminate" quality for all measurement properties. The Knee injury and Osteoarthritis Outcome Score patellofemoral subscale (KOOS-PF) had "low" to "high" quality evidence for a rating of "sufficient" for 4 measurement properties. The Lower Extremity Functional Scale (LEFS) had very low-quality evidence for a "sufficient" rating for 4 measurement properties. The KOOS-PF and LEFS were rated "indeterminate" for structural validity and internal consistency. The KOOS-PF had the best interpretability with reported minimal important change and 0% ceiling and floor effects. No studies examined cross-cultural validity. CONCLUSION: The KOOS-PF and LEFS had the strongest measurement properties among PROMs used for PFP. More research is needed, particularly regarding structural validity and interpretability of PROMs. J Orthop Sports Phys Ther 2023;53(8):1-20. Epub: 20 June 2023. doi:10.2519/jospt.2023.11730.

Patient-Reported Outcome Measures for Adults and Adolescents with Patellofemoral Pain: A Systematic Review of Content Validity and Feasibility Using the COSMIN Methodology

OBJECTIVE: To assess the content validity and feasibility of patient-reported outcome measures (PROMs) used to assess pain and function in adults and adolescents with patellofemoral pain (PFP). DESIGN: Systematic review. LITERATURE SEARCH: We searched the databases PubMed, CINAHL, Scopus, SPORTDiscus, and the Cochrane Library from inception to January 6, 2022. STUDY SELECTION CRITERIA: We included studies that described the development or evaluation of the content validity of English-language PROMs for PFP, as well as their translations and cultural adaptations to different languages. DATA SYNTHESIS: Using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology, we determined overall ratings and quality of evidence for the relevance, comprehensiveness, and comprehensibility of PROMs. We extracted data related to feasibility for clinical use (eg, administration time and scoring ease). RESULTS: Forty-three studies for 33 PROMs were included. The overall quality of most studies was "inadequate" due to failure to engage stakeholders and/or ensure adherence to rigorous qualitative research procedures. Of all PROMs evaluated, the Knee injury and Osteoarthritis Outcome Score-Patellofemoral subscale (KOOS-PF), was the only PROM with sufficient content validity components. Quality of evidence for content validity of the KOOS-PF was low. Most PROMs were rated feasible for clinical and research purposes. CONCLUSION: Most PROMs used to measure pain and function in patients with PFP have inadequate content validity. The KOOS-PF had the highest overall content validity. We recommend the KOOS-PF for evaluating pain and function (in research and clinical practice) in adults and adolescents with PFP. J Orthop Sports Phys Ther 2023;53(1):23-39. Epub: 18 October 2022. doi:10.2519/jospt.2022.11317.

Knee proprioceptive function and physical performance of patients with patellofemoral pain: A matched case-control study

BACKGROUND

Patients with patellofemoral pain (PFP) present pain, functional limitation, and alteration in knee proprioception.

PURPOSE

To compare the knee joint position sense and lower extremity functionality between patients with PFP and controls. Secondarily, investigate the relationship between proprioceptive acuity and physical performance.

METHODS

This is a matched case-control study including 48 patients with PFP and 48 healthy individuals matched by age, sex, weight, height, and limb dominance. The proprioceptive evaluation was performed using the joint position sense test (absolute error and relative error) and functionality was assessed using the Single-Leg Triple-Hop test and the Y-Balance Test. The groups were compared using the independent student's T-test. Proprioceptive acuity and physical performance correlations were determined by Pearson correlation coefficient.

RESULTS

Participants were on average 31 years old and 62.5% were men. There was no statistically difference for absolute and relative angular error between groups. Patients presented lower relative reached distance on the anterior direction of the Y-Balance Test than controls [patients=58.6 (6.6) % versus controls=61.7 (5.9) %, p=.020]. No differences between groups were found for other functional measures. Significant correlation was found between absolute angular error and anterior component at 60° (r=0.225, p=.028) and relative angular error at 60° with the posterolateral component of the Y- Balance Test (r=0.231, p=.024).

CONCLUSION

Proprioceptive acuity of patients with PFP was not reduced. The anterior direction of the Y-Balance Test was impaired compared to matched controls. Proprioceptive sense is related to dynamic balance but not to jump ability.

Additional effects of core stability exercises on pain and function of patients with patellofemoral pain: A randomized controlled trial

Background/purpose:

Recently, there is more emphasis on the role of core muscles in pathogenesis and rehabilitation of patellofemoral pain (PFP). We aimed to investigate whether increased core muscle strength and endurance improve clinical outcomes.

Methods:

In a randomized controlled trial, 60 patients (M/F: 25/35, age = 32.28 (5.9) years) with PFP were randomly allocated into two groups of routine exercise (control) and combined core plus routine exercise (intervention). Home exercise was scheduled at least 5 times/week for 12 weeks. We assessed the outcomes of pain (Visual analogue scale) and function (Anterior knee pain score) before and immediately after interventions.

Results:

Significant improvements were reported in both groups (P < 0.001). There were significant between-group differences in both outcomes in favor of the intervention (Pain: 12.4, CI 95%: 7.1–17.8, P < 0.001; Function: 6.4, CI 95%: 2.2–10.5, P = 0.003).

Conclusion:

Outcome improvements were significantly greater in intervention group. Inclusion of core stability exercises may lead to additional benefits.

Patellofemoral Pain

Patellofemoral pain (PFP) is a common musculoskeletal-related condition that is characterized by insidious onset of poorly defined pain, localized to the anterior retropatellar and/or peripatellar region of the knee. The onset of symptoms can be slow or acutely develop with a worsening of pain accompanying lower-limb loading activities (eg, squatting, prolonged sitting, ascending/descending stairs, jumping, or running). Symptoms can restrict participation in physical activity, sports, and work, as well as recur and persist for years. This clinical practice guideline will allow physical therapists and other rehabilitation specialists to stay up to date with evolving PFP knowledge and practices, and help them to make evidence-based treatment decisions. J Orthop Sports Phys Ther. 2019;49(9):CPG1-CPG95. doi:10.2519/jospt.2019.0302.

Clinical Outcomes After the Nonoperative Management of Lateral Patellar Dislocations: A Systematic Review

Background:

The first-line treatment for patellar dislocations is often nonoperative and consists of physical therapy and immobilization techniques, with various adjuncts employed. However, the outcomes of nonoperative therapy are poorly described, and there is a lack of quality evidence to define the optimal intervention.

Purpose:

To perform a comprehensive review of the literature and assess the quality of studies presenting patient outcomes from nonoperative interventions for patellar dislocations.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

The MEDLINE, AMED, Embase, CINAHL, Cochrane Library, PEDro, and SPORTDiscus electronic databases were searched through July 2017 by 3 independent reviewers. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. Study quality was assessed using the CONSORT (Consolidated Standards for Reporting Trials) criteria for randomized controlled trials and the Newcastle-Ottawa Scale for cohort studies and case series.

Results:

A total of 25 studies met our inclusion criteria, including 12 randomized controlled trials, 7 cohort studies, and 6 case series, consisting of 1066 patients. Studies were grouped according to 4 broad categories of nonoperative interventions based on immobilization, weightbearing status, quadriceps exercise type, and alternative therapies. The most commonly used outcome measure was the Kujala score, and the pooled redislocation rate was 31%.

Conclusion:

This systematic review found that patient-reported outcomes consistently improved after all methods of treatment but did not return to normal. Redislocation rates were high and close to the redislocation rates reported in natural history studies. There is a lack of quality evidence to advocate the use of any particular nonoperative technique for the treatment of patellar dislocations.

Value of History, Physical Examination, and Radiographic Findings in the Diagnosis of Symptomatic Meniscal Tear Among Middle-Aged Subjects With Knee Pain

OBJECTIVE

To evaluate the utility of clinical history, radiographic findings, and physical examination findings in the diagnosis of symptomatic meniscal tear (SMT) in patients over age 45 years, in whom concomitant osteoarthritis is prevalent.

METHODS

In a cross-sectional study of patients from 2 orthopedic surgeons' clinics, we assessed clinical history, physical examination findings, and radiographic findings in patients age >45 years with knee pain. The orthopedic surgeons rated their confidence that subjects' symptoms were due to meniscal tear; we defined the diagnosis of SMT as at least 70% confidence. We used logistic regression to identify factors independently associated with diagnosis of SMT, and we used the regression results to construct an index of the likelihood of SMT.

RESULTS

In 174 participants, 6 findings were associated independently with the expert clinician having ≥70% confidence that symptoms were due to meniscal tear: localized pain, ability to fully bend the knee, pain duration <1 year, lack of varus alignment, lack of pes planus, and absence of joint space narrowing on radiographs. The index identified a low-risk group with 3% likelihood of SMT.

CONCLUSION

While clinicians traditionally rely upon mechanical symptoms in this diagnostic setting, our findings did not support the conclusion that mechanical symptoms were associated with the expert's confidence that symptoms were due to meniscal tear. An index that includes history of localized pain, full flexion, duration <1 year, pes planus, varus alignment, and joint space narrowing can be used to stratify patients according to their risk of SMT, and it identifies a subgroup with very low risk.

The relationship between quadriceps strength and joint position sense, functional outcome and painful activities in patellofemoral pain syndrome

PURPOSE

The aim of this study was to investigate how strongly the concentric and eccentric quadriceps strengths were correlated with the joint position sense, functional outcomes and painful activities in patients with patellofemoral pain syndrome (PFPS).

METHODS

The study included forty-six women diagnosed with unilateral PFPS. Eccentric and concentric quadriceps strengths were recorded at 60 and 180°/s. Active knee joint position sense (JPS) was measured at 20° and 60° of flexion. Functional levels were determined by using Kujala patellofemoral scores. Pain levels during stair descending and ascending, squatting and prolonged sitting were measured using 0-10 cm visual analogue scale. The relationship of isokinetic quadriceps strength with JPS results, Kujala score and pain levels were evaluated using Spearman's correlation coefficient test.

RESULTS

Eccentric and concentric quadriceps strengths were significantly lower on involved side than uninvolved side. JPS results were poorer on the painful knee when compared to uninvolved side. While eccentric strength correlated with both JPS target angles, concentric strength was correlated only with 20°. Both eccentric and concentric strengths were significantly correlated with Kujala scores and pain levels.

CONCLUSION

Quadriceps eccentric strength was correlated more to joint position sense than concentric strength. Both eccentric and concentric quadriceps strength related to pain and functional level in PFPS patients.

A questionnaire to identify patellofemoral pain in the community: an exploration of measurement properties

BACKGROUND

Community-based studies of patellofemoral pain (PFP) need a questionnaire tool that discriminates between those with and those without the condition. To overcome these issues, we have designed a self-report questionnaire which aims to identify people with PFP in the community.

METHODS

STUDY DESIGNS

comparative study and cross-sectional study.

STUDY POPULATION

comparative study: PFP patients, soft-tissue injury patients and adults without knee problems. Cross-sectional study: adults attending a science festival.

INTERVENTION

comparative study participants completed the questionnaire at baseline and two weeks later. Cross-sectional study participants completed the questionnaire once. The optimal scoring system and threshold was explored using receiver operating characteristic curves, test-retest reliability using Cohen's kappa and measurement error using Bland-Altman plots and standard error of measurement. Known-group validity was explored by comparing PFP prevalence between genders and age groups.

RESULTS

Eighty-four participants were recruited to the comparative study. The receiver operating characteristic curves suggested limiting the questionnaire to the clinical features and knee pain map sections (AUC 0.97 95 % CI 0.94 to 1.00). This combination had high sensitivity and specificity (over 90 %). Measurement error was less than the mean difference between the groups. Test-retest reliability estimates suggest good agreement (N = 51, k = 0.74, 95 % CI 0.52-0.91). The cross-sectional study (N = 110) showed expected differences between genders and age groups but these were not statistically significant.

CONCLUSION

A shortened version of the questionnaire, based on clinical features and a knee pain map, has good measurement properties. Further work is needed to validate the questionnaire in community samples.

Additional Effects of an Individualized Risk Factor-Based Approach on Pain and the Function of Patients With Patellofemoral Pain Syndrome: A Randomized Controlled Trial

OBJECTIVE

To investigate the clinical efficacy of adding risk factor-based approach (including appropriate exercises and orthoses) to routine quadriceps strengthening exercise with respect to pain and function in patients with patellofemoral pain syndrome (PFPS).

DESIGN

A parallel group nonblinded randomized controlled trial with 12-week follow-up.

SETTING

An outpatient Sports Medicine Clinic of Tehran University of Medical Sciences, Tehran, Iran.

PARTICIPANTS

Patients (both sexes, 18-40 years) with clinically diagnosed PFPS of the duration over 2 months.

INTERVENTION

The intervention group received an individualized program, including exercise therapy plus risk factor modification, and was instructed to practice the tailored interventions at home for 12 weeks. The control group received an exercise program, only focusing on quadriceps strengthening.

MAIN OUTCOME MEASURES

The primary outcomes were pain severity during the activities of daily living (0- to 100-point visual analog scale), and function (0- to 100-point Kujala patellofemoral score) at a 12-week follow-up.

RESULTS

A total of 53 participants completed the trial: 26 in the intervention and 27 in the control group. After 12 weeks, both groups showed improvements in pain and function, but the changes were significantly greater in the intervention group with regard to pain [adjusted difference, -14.90; 95% confidence interval (CI), -5.86 to -23.93, P = 0.002], and function (adjusted difference, 6.82; 95% CI, 2.54-11.10, P = 0.002).

CONCLUSIONS

Assessment and modification of the risk factors may add to the treatment effects on pain and function at a 12-week follow-up in patients with PFPS. These findings may lead to a more comprehensive clinical approach to this very common problem.

CLINICAL RELEVANCE

It seems that incorporating risk factor assessment into our clinical practice may add to treatment effects with regard to pain and function in patients with PFPS.

Exercise for treating patellofemoral pain syndrome

BACKGROUND

Patellofemoral pain syndrome (PFPS) is a common knee problem, which particularly affects adolescents and young adults. PFPS, which is characterised by retropatellar (behind the kneecap) or peripatellar (around the kneecap) pain, is often referred to as anterior knee pain. The pain mostly occurs when load is put on the knee extensor mechanism when climbing stairs, squatting, running, cycling or sitting with flexed knees. Exercise therapy is often prescribed for this condition.

OBJECTIVES

To assess the effects (benefits and harms) of exercise therapy aimed at reducing knee pain and improving knee function for people with patellofemoral pain syndrome.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (May 2014), the Cochrane Central Register of Controlled Trials (2014, Issue 4), MEDLINE (1946 to May 2014), EMBASE (1980 to 2014 Week 20), PEDro (to June 2014), CINAHL (1982 to May 2014) and AMED (1985 to May 2014), trial registers (to June 2014) and conference abstracts.

SELECTION CRITERIA

Randomised and quasi-randomised trials evaluating the effect of exercise therapy on pain, function and recovery in adolescents and adults with patellofemoral pain syndrome. We included comparisons of exercise therapy versus control (e.g. no treatment) or versus another non-surgical therapy; or of different exercises or exercise programmes.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials based on pre-defined inclusion criteria, extracted data and assessed risk of bias. Where appropriate, we pooled data using either fixed-effect or random-effects methods. We selected the following seven outcomes for summarising the available evidence: pain during activity (short-term: ≤ 3 months); usual pain (short-term); pain during activity (long-term: > 3 months); usual pain (long-term); functional ability (short-term); functional ability (long-term); and recovery (long-term).

MAIN RESULTS

In total, 31 heterogeneous trials including 1690 participants with patellofemoral pain are included in this review. There was considerable between-study variation in patient characteristics (e.g. activity level) and diagnostic criteria for study inclusion (e.g. minimum duration of symptoms) and exercise therapy. Eight trials, six of which were quasi-randomised, were at high risk of selection bias. We assessed most trials as being at high risk of performance bias and detection bias, which resulted from lack of blinding.The included studies, some of which contributed to more than one comparison, provided evidence for the following comparisons: exercise therapy versus control (10 trials); exercise therapy versus other conservative interventions (e.g. taping; eight trials evaluating different interventions); and different exercises or exercise programmes. The latter group comprised: supervised versus home exercises (two trials); closed kinetic chain (KC) versus open KC exercises (four trials); variants of closed KC exercises (two trials making different comparisons); other comparisons of other types of KC or miscellaneous exercises (five trials evaluating different interventions); hip and knee versus knee exercises (seven trials); hip versus knee exercises (two studies); and high- versus low-intensity exercises (one study). There were no trials testing exercise medium (land versus water) or duration of exercises. Where available, the evidence for each of seven main outcomes for all comparisons was of very low quality, generally due to serious flaws in design and small numbers of participants. This means that we are very unsure about the estimates. The evidence for the two largest comparisons is summarised here. Exercise versus control. Pooled data from five studies (375 participants) for pain during activity (short-term) favoured exercise therapy: mean difference (MD) -1.46, 95% confidence interval (CI) -2.39 to -0.54. The CI included the minimal clinically important difference (MCID) of 1.3 (scale 0 to 10), indicating the possibility of a clinically important reduction in pain. The same finding applied for usual pain (short-term; two studies, 41 participants), pain during activity (long-term; two studies, 180 participants) and usual pain (long-term; one study, 94 participants). Pooled data from seven studies (483 participants) for functional ability (short-term) also favoured exercise therapy; standardised mean difference (SMD) 1.10, 95% CI 0.58 to 1.63. Re-expressed in terms of the Anterior Knee Pain Score (AKPS; 0 to 100), this result (estimated MD 12.21 higher, 95% CI 6.44 to 18.09 higher) included the MCID of 10.0, indicating the possibility of a clinically important improvement in function. The same finding applied for functional ability (long-term; three studies, 274 participants). Pooled data (two studies, 166 participants) indicated that, based on the 'recovery' of 250 per 1000 in the control group, 88 more (95% CI 2 fewer to 210 more) participants per 1000 recovered in the long term (12 months) as a result of exercise therapy. Hip plus knee versus knee exercises. Pooled data from three studies (104 participants) for pain during activity (short-term) favoured hip and knee exercise: MD -2.20, 95% CI -3.80 to -0.60; the CI included a clinically important effect. The same applied for usual pain (short-term; two studies, 46 participants). One study (49 participants) found a clinically important reduction in pain during activity (long-term) for hip and knee exercise. Although tending to favour hip and knee exercises, the evidence for functional ability (short-term; four studies, 174 participants; and long-term; two studies, 78 participants) and recovery (one study, 29 participants) did not show that either approach was superior.

AUTHORS' CONCLUSIONS

This review has found very low quality but consistent evidence that exercise therapy for PFPS may result in clinically important reduction in pain and improvement in functional ability, as well as enhancing long-term recovery. However, there is insufficient evidence to determine the best form of exercise therapy and it is unknown whether this result would apply to all people with PFPS. There is some very low quality evidence that hip plus knee exercises may be more effective in reducing pain than knee exercise alone.Further randomised trials are warranted but in order to optimise research effort and engender the large multicentre randomised trials that are required to inform practice, these should be preceded by research that aims to identify priority questions and attain agreement and, where practical, standardisation regarding diagnostic criteria and measurement of outcome.

Effects of physical therapist-guided quadriceps-strengthening exercises for the treatment of patellofemoral pain syndrome: a systematic review

STUDY DESIGN

Systematic literature review.

OBJECTIVE

To summarize the evidence for physical therapist-guided quadriceps-strengthening exercises as a treatment for patellofemoral pain syndrome.

BACKGROUND

Although quadriceps strengthening is often included in the plan of care for patellofemoral pain syndrome, a systematic review published in 2003 found only limited evidence that exercise was more effective than no exercise for this common condition.

METHODS

The PubMed, Embase/MEDLINE, and Cochrane Central Register of Controlled Trials databases, from inception to January 9, 2014, were searched for randomized controlled trials comparing the use of quadriceps-strengthening exercises to interventions consisting of advice/information or a placebo. Outcomes of interest were pain measures and function, as measured with self-report questionnaires. The methodological quality of the randomized controlled trials was assessed with the Physiotherapy Evidence Database scale. Results were summarized using a best-evidence synthesis and graphically illustrated using forest plots without meta-analysis.

RESULTS

Seven studies were included in the literature review. These studies reported strong evidence that isolated quadriceps strengthening is more effective in reducing pain and improving function than advice and information alone. In addition, compared to advice and information or placebo, there was strong evidence that quadriceps-strengthening exercises combined with other interventions may be more effective in reducing pain immediately postintervention and after 12 months, but not in improving function.

CONCLUSION

The literature provides strong evidence for the use of quadriceps-strengthening exercises, with or without other interventions, for the treatment of patellofemoral pain syndrome.

Patellofemoral pain syndrome and modifiable intrinsic risk factors; how to assess and address?

Patellofemoral pain syndrome (PFPS) is a very common disorder of the knee. Due to multiple forces influencing the patellofemoral joint, clinical management of this ailment is particularly intricate. Patellofemoral pain syndrome has a multifactorial nature and multiple parameters have been proposed as potential risk factors, classified as intrinsic or extrinsic. Some of the intrinsic risk factors are modifiable and may be approached in treatment. A number of modifiable risk factors have been suggested, including quadriceps weakness, tightness of hamstring, iliopsoas and gastrosoleus muscles, hip muscles dysfunction, foot overpronation, tightness of iliotibial band, generalised joint laxity, limb length discrepancy, patellar malalignment and hypermobility. In general, the routine approach of physicians to this problem does not include assessment and modification of these risk factors and therefore, it may negatively affect the management outcomes. Changing this approach necessitates an easy and practical protocol for assessment of modifiable risk factors and effective and feasible measures to address them. In this review, we aimed to introduce assessment and intervention packages appropriate for this purpose.

A clinical study of the biomechanics of step descent using different treatment modalities for patellofemoral pain

INTRODUCTION

In the previous study we have demonstrated that in healthy subjects significant changes in coronal and transverse plane mechanics can be produced by the application of a neutral patella taping technique and a patellar brace. Recently it has also been identified that patients with patellofemoral pain syndrome (PFPS) display alterations in gait in the coronal and transverse planes.

OBJECTIVE

This study investigated the effect of patellar bracing and taping on the three-dimensional mechanics of the knee of patellofemoral pain patients during a step descent task.

METHOD

Thirteen patients diagnosed with patellofemoral pain syndrome performed a slow step descent. This was conducted under three randomized conditions: (a) no intervention, (b) neutral patella taping, (c) patellofemoral bracing. A 20cm step was constructed to accommodate an AMTI force platform. Kinematic data were collected using a ten camera infra-red Oqus motion analysis system. Reflective markers were placed on the foot, shank and thigh using the Calibrated Anatomical System Technique (CAST).

RESULTS

The coronal plane knee range of motion was significantly reduced with taping (P=0.031) and bracing (P=0.005). The transverse plane showed a significant reduction in the knee range of motion with the brace compared to taping (P=0.032) and no treatment (P=0.046).

CONCLUSION

Patients suffering from patellofemoral pain syndrome demonstrated improved coronal plane and torsional control of the knee during slow step descent following the application of bracing and taping. This study further reinforces the view that coronal and transverse plane mechanics should not be overlooked when studying patellofemoral pain.

Anterior knee pain and cold knees: a possible association in women

Abnormal reactions to environmental cold have been observed in some patients with Anterior Knee Pain (AKP). The aims of this study were to investigate whether palpation of the knee could classify patients into those with and those without cold knees; whether this classification could be objectively validated using thermal imaging; whether the cold and not cold knee groups varied in response to a cold stress test and in patient-reported measures. Fifty eight patients were recruited; palpation classified them into cold and not cold groups. Twenty-one (36%) patients were classified as having a cold knee by palpation: fourteen (36%) females and seven males (37%). Preliminary analysis suggested gender might be an effect modifier and the number of men was small, therefore the analysis focussed on females. Women with cold knees had a significantly smaller patellar skin fold, lower levels of activity and worse scores on the MFIQ, there also appeared to be an association with a traumatic onset. Women with cold knees were more likely to report cold weather affected their knees and they preferred a hot water bottle compared to an ice-pack on their knee; there was also a trend towards having to wear extra tights/long johns in the winter. This study has helped to define a clinical profile for a group of females with AKP and cold knees. This group appears to demonstrate a mild form of Reflex Sympathetic Dystrophy.

Disability in patients with chronic patellofemoral pain syndrome: a randomised controlled trial of VMO selective training versus general quadriceps strengthening

This study was a prospective single blind randomised controlled trial to compare the effects of rehabilitation with emphasis on retraining the vastus medialis (VMO) component of the quadriceps femoris muscle and rehabilitation with emphasis on general strengthening of the quadriceps femoris muscles on pain, function and Quality of Life in patients with patellofemoral pain syndrome (PFPS). Patients with PFPS (n=69) were recruited from a hospital orthopaedic clinic and randomised into three groups: (1) physiotherapy with emphasis on selectively retraining the VMO (Selective); (2) physiotherapy with emphasis on general strengthening of the quadriceps femoris muscles (General); and (3) a no-treatment control group (Control). The three groups were then compared before and after an eight-week rehabilitation period. The Selective and General groups demonstrated statistically significant and 'moderate' to 'large' effect size reductions in pain when compared to the Control group. Both the Selective and General groups displayed statistically significant and 'moderate' and 'large' effect size improvements in subjective function and Quality of Life compared to the Control group. Knee flexion excursion during the stance phase of gait, demonstrated that there were no statistical significant differences and only 'trivial' to 'small' effect size differences between the Selective or General groups and the Control group. A large number of PFPS patients can experience significant improvements in pain, function and Quality of Life, at least in the short term, with quadriceps femoris rehabilitation, with or without emphasis on selective activation of the VMO component. Both approaches would seem acceptable for rehabilitating patients with PFPS. It may be appropriate to undertake exercises involving selective activation of the vastus medialis early in the rehabilitation process, however, clinicians should not overly focus on selective activation before progressing rehabilitation, especially in more chronic cases with significant participation restrictions.

The biomechanics of step descent under different treatment modalities used in patellofemoral pain

BACKGROUND

Most previous work on the use of knee bracing and taping has focussed on sagittal plane movement. However, most bracing and taping techniques aim to modify patellar movement in the coronal and transverse planes.

OBJECTIVE

This study investigated the effect of patellar bracing and taping on the three-dimensional mechanics of the knee during a controlled eccentric step down task.

METHOD

Twelve healthy subjects were asked to conduct a slow step down exercise. The step down was conducted under three randomised conditions: (a) no intervention, (b) neutral patella taping and (c) patellofemoral bracing. A step was constructed to accommodate an AMTI force platform and to produce a step height of 20 cm. Kinematic data were collected using a six camera ProReflex motion analysis system. Reflective markers were placed on the foot, shank and thigh using the Calibrated Anatomical Systems Technique (CAST).

RESULTS

The patellofemoral brace and taping led to a significant reduction in the maximum coronal and range of torsional knee angles by 5 degrees and 2 degrees , respectively (p=0.030, 0.006). The range of coronal and transverse plane knee moments was also significantly reduced by 0.15 Nm/kg and 0.03 Nm/kg (p=0.020, 0.0019). The brace was shown to be more effective in the coronal and transverse planes in comparison to taping or no intervention.

CONCLUSION

Bracing and taping appear to offer coronal plane and torsional control of the knee during eccentric step descent. Coronal and transverse plane mechanics should not be overlooked when studying patellofemoral pain.

Effects of patellar taping on knee joint proprioception in patients with patellofemoral pain syndrome

The aim of this study was to assess the effect of patellar taping of the proprioceptive status of patients with patellofemoral pain syndrome (PFPS). A total of 32 subjects (18 males, 14 females of age 31.9 +/- 11.2, body mass index 25.8 +/- 5.3) with PFPS were tested for Joint Position Sense (JPS) using a Biodex dynamometer. Outcomes of interest were the absolute error (AE), the variable error (VE) and the relative error (RE) of the JPS values for both active (AAR) and passive (PAR) angle reproduction at an angular velocity of 2 degrees /s with a start angle at 90 degrees and target angles of 60 degrees and 20 degrees . Taping was applied in random order across the patella of each subject with each of the subjects acting as their own internal control. Results indicated initially that application of patellar tape did not enhance and in some cases worsened the JPS of the subjects (P > 0.05). However, when the subjects' proprioceptive status was graded according to their closeness to the target angles into 'good' (5 degrees , N = 10) and 'poor' ( > 5 degrees , N = 22) taping enhanced nearly all values of those with 'poor' proprioception, with AE at 20 degrees to statistical significance (P = 0.021). In conclusion, this study has shown that patellar taping did not improve the AAR and PAR JPS tests of a whole sample of 32 PFPS patients. It also has shown that a subgroup of PFPS patients with poor proprioception may exist and be helped by patellar taping.

An investigation into the effect of number of trials during proprioceptive testing in patients with patellofemoral pain syndrome

The purpose of this study was to investigate the effect of increasing the number of test trials in the assessment of knee joint position sense, in a group of patellofemoral patients, and second, to investigate the effects of joint angle and type of test. Thirty-two patients with a diagnosis of patellofemoral pain syndrome were admitted to this study. Knee joint position sense was measured by performing an ipsilateral matching activity at target angles of 20 degrees and 60 degrees using two techniques; Passive Angle Reproduction (PAR), and Active Angle Reproduction (AAR). The results show that five repetitions are required for AAR and six for PAR. A two-way repeated-measures ANOVA showed that there was no significant difference (p = 0.559) in the accuracy of angle reproduction for the two angles (60 degrees and 20 degrees ); however, there was a significant difference (p = 0.001) between the two types of test (AAR and PAR). The results of this study have implications for clinicians and researchers who examine knee joint proprioception as part of functional assessment in a variety of knee joint pathologies including PFPS. A "quick" one-off assessment of knee joint position sense may give erroneous data; subjects need to have several trials before a true picture of their proprioceptive status emerges. Type of testing performed, active or passive, is also important, although the angle of testing may not be relevant.

Diagnostic value of five clinical tests in patellofemoral pain syndrome

The current study is aimed at examining the validity of five clinical patellofemoral tests used in the diagnosis of patellofemoral pain syndrome (PFPS). Forty-five knee patients were divided into either the PFPS or the non-PFPS group, based on the fulfilment of the diagnostic criteria for PFPS. An investigator, blinded to the group assignment, performed the vastus medialis coordination test, patellar apprehension test, Waldron's test, Clarke's test, and the eccentric step test. The positive likelihood ratio was 2.26 for both the vastus medialis coordination test and the patellar apprehension test. For the eccentric step test, the positive likelihood ratio was 2.34. A positive outcome on either the vastus medialis coordination test, the patellar apprehension test, or the eccentric step test increases the probability of PFPS to a small, but sometimes important, degree. For the remaining tests, the positive likelihood ratios were below the threshold value of 2, indicating that given a positive test result, the probability that the patient has PFPS is altered to a small, and rarely important degree. The negative likelihood ratios for all tests exceeded the threshold value of 0.5, suggestive of clinically irrelevant information. These data question the validity of clinical tests for the diagnosis of PFPS.

Effects of taping on pain and function in patellofemoral pain syndrome: a randomized controlled trial

STUDY DESIGN

A randomized controlled trial.

OBJECTIVES

To investigate the effectiveness of daily patella taping and exercise on pain and function in individuals with patellofemoral pain syndrome.

BACKGROUND

Patella taping and muscle-strengthening programs are commonly used to treat patellofemoral pain syndrome. There is, however, little evidence for the effectiveness of these approaches.

METHODS AND MEASURES

Twenty-four men and 6 women aged 17 to 25 years (mean +/- SD, 18.7 +/- 1.2 years) participated in the study. Subjects were randomly and exclusively assigned to 1 of 3 treatment groups: patella taping combined with a standardized exercise program, placebo patella taping and exercise program, or exercise program alone (n = 10 in each group). Taping was applied and exercises performed on a daily basis for 4 weeks. Outcome measures were visual analog scales for pain and the functional index questionnaire, recorded at weekly intervals by a therapist who was blinded to group allocation.

RESULTS

Separate mixed-model ANOVAs, with repeated measures on time, indicated statistically significant improvements in pain and function over time for all groups (P<.01) and also significant differences between groups for all measures (P<.01). Separate independent samples t tests showed that the group receiving taping and exercises had better pain and function scores following treatment than the placebo taping-and-exercise group and the exercise-alone group. There were no significant differences between the placebo taping-and-exercise group and exercise-alone group at any time point.

CONCLUSIONS

These findings indicate that over a period of 4 weeks a combination of daily patella taping and exercises was successful in improving pain and function in individuals with patellofemoral pain syndrome. The combination of patella taping and exercise was superior to the use of exercise alone.

A comparison of eccentric isokinetic torque production and velocity of knee flexion angle during step down in patellofemoral pain syndrome patients and unaffected subjects

OBJECTIVE

To determine knee angular velocity changes during stair descent and slow velocity eccentric isokinetic quadriceps contraction, in normal controls and patellofemoral pain syndrome patients.

DESIGN

Isokinetic and kinematic analysis of the performance of patellofemoral pain syndrome patients and matched normal controls.

BACKGROUND

In the presence of increased patellofemoral joint stresses, patellofemoral pain syndrome patients have been shown to adopt compensatory strategies to minimise joint loading and therefore pain. One of the compensatory strategies reported, is that of the break phenomena, which results in a change quadriceps torque production.

METHODS

Twenty female patients with patellofemoral pain syndrome and 20 asymptomatic matched controls participated in the study. All subjects had their isokinetic eccentric and concentric quadriceps torque assessed at 30 degrees/second and 2-dimensional video data taken when descending from a step. Variations in knee angular velocity and torque curves were then identified.

RESULTS

None of the subjects demonstrated a break on isokinetic concentric quadriceps contraction. Of the patellofemoral pain syndrome patients, 50% (10 out of 20) had a break in eccentric torque curve on testing, compared with 15% (3 out of 20) of the controls. Abnormal curve perturbation was demonstrated to occur in none of the controls isokinetically, but 20% (4 out 20) of the patellofemoral pain syndrome patients had perturbations in their torque curves. On stair decent a break was seen in 60% (12 out of 20) of the patellofemoral pain syndrome patients and 15% (3 out of 20) of the control subjects on analysis of the knee angular velocity. Twenty percent (4 out of 20) of the patellofemoral pain syndrome patients and 10% (2 out of 20) of the controls had abnormal curve perturbation on analysis of their stair descent.

CONCLUSIONS

The implications are that there appears to be a relationship between patellofemoral pain syndrome and control of eccentric quadriceps contraction. This relationship is possibly related to joint and soft tissue loading not just the degree of pain, with the break being a saving reflex to prevent further stress.

RELEVANCE

Exercise to rehabilitate the quadriceps in patellofemoral pain syndrome should be chosen with regard to joint loading and range of movement as well as velocity of contraction, in order to facilitate quadriceps activation as opposed to inhibiting it.

Cold legs: a potential indicator of negative outcome in the rehabilitation of patients with patellofemoral pain syndrome

PURPOSE

The purpose of this paper is to explore the link between a poor outcome in response to an exercise based approach to physiotherapy, in patients with patellofemoral dysfunction and a self-report of legs feeling cold even in warm surroundings.

SCOPE

The study was carried out in the physiotherapy outpatients department of Burnley General Hospital, Lancashire, UK with 87 consecutively referred patients with a diagnosis of patellofemoral pain syndrome being assessed for suitability for entry into the study. Of these 77 entered the study with 14 (18%), of these responding 'Yes' to the question 'Do your legs feel cold even in warm surroundings?' All patients were assessed using four outcome measures prior to the commencement of a standardised rehabilitation programme consisting of lower limb biarticular muscle stretching, vastus medialis training and patella taping or biofeedback. The patients were reassessed using the same outcome measures 3 months after completing their course of treatment.

CONCLUSIONS

Patients who responded 'Yes' to the question 'Do your legs feel cold even in warm surroundings?' reported higher pain levels and tolerated less physical activity than non-cold sufferers at initial assessment, these differences were statistically significant. The cold sufferers showed less improvement on all of the outcome measures although the differences between the two groups only reached statistical significance for one of the outcome measures. The implications of this in relation to clinical practice are discussed.