Management of patellofemoral pain syndrome

Patellofemoral pain syndrome (PFPS) is the most common cause of knee pain in the outpatient setting. It is caused by imbalances in the forces controlling patellar tracking during knee flexion and extension, particularly with overloading of the joint. Risk factors include overuse, trauma, muscle dysfunction, tight lateral restraints, patellar hypermobility, and poor quadriceps flexibility. Typical symptoms include pain behind or around the patella that is increased with running and activities that involve knee flexion. Findings in patients with PFPS range from limited patellar mobility to a hypermobile patella. To confirm the diagnosis, an examination of the knee focusing on the patella and surrounding structures is essential. For many patients with the clinical diagnosis of PFPS, imaging studies are not necessary before beginning treatment. Radiography is recommended in patients with a history of trauma or surgery, those with an effusion, those older than 50 years (to rule out osteoarthritis), and those whose pain does not improve with treatment. Recent research has shown that physical therapy is effective in treating PFPS. There is little evidence to support the routine use of knee braces or nonsteroidal anti-inflammatory drugs. Surgery should be considered only after failure of a comprehensive rehabilitation program. Educating patients about modification of risk factors is important in preventing recurrence.     

Acupuncture treatment of patellofemoral pain syndrome

OBJECTIVE: To evaluate the effect of acupuncture treatment in patellofemoral pain syndrome. DESIGN: A controlled trial where patients were randomly assigned either to acupuncture treatment or no treatment. Evaluation of the result was blinded. SETTING: An acupuncture/physiotherapy treatment practice in Bergen, Norway. SUBJECTS: A total of 75 patients with patellofemoral pain syndrome were included, of whom 44 were female. INTERVENTION: Individualized acupuncture treatment twice weekly for 4 weeks. MAIN OUTCOME MEASURE: Patients were followed for 1 year with the Cincinnati Knee Rating System (CKRS) scale as the main outcome measure. Other tests used were the Stairs-Hopple test, quadriceps atrophy, and evaluating level pain after activity by a visual analogue scale. RESULTS: At inclusion patients, aged 18-45 (mean 31.0) years, reported persistent pain on activity (mean 6.6 years) and at rest (mean 4.3 years). CRS scores at baseline were similar (acupuncture group 58.0 versus no treatment group 56.1). At 12 months there was a significant difference in the CRS score between the groups (acupuncture 75.2 versus no treatment 61.7, p = 0.005). When analyzing for worst case, the difference persisted (68.1 versus 54.4, p = 0.03). Results were then dichotomized as to whether the patient was cured or not at 12 months. A patient was defined as cured if he/she scored "slight" or "none" on the "pain" or "limitation to activity" subscales. The Number Necessary to Treat (NNT) to cure one patient was NNT = 3.0 for the CRS pain subscale and NNT = 3.7 for the CRS function subscale. CONCLUSION: We conclude that acupuncture may be an alternative treatment for patellofemoral pain syndrome.     

Physical examination and patellofemoral pain syndrome

Patellofemoral pain syndrome, which accounts for 25% of all sports-related knee injuries, is multifactorial in origin. A combination of variables, including abnormal lower limb biomechanics, soft-tissue tightness, muscle weakness, and excessive exercise, may result in increased cartilage and subchondral bone stress, patellofemoral pain, and subtle or more overt patellar maltracking. Because of the multiple forces affecting the patellofemoral joint, the clinical evaluation and treatment of this disorder is challenging. An extensive search of the literature revealed no single gold-standard test maneuver for that disorder, and the reliability of the maneuvers described was generally low or untested. An abnormal Q-angle, generalized ligamentous laxity, hypomobile or hypermobile tenderness of the lateral patellar retinaculum, patellar tilt or mediolateral displacement, decreased flexibility of the iliotibial band and quadriceps, and quadriceps, hip abductor, and external rotator weakness were most often correlated with patellofemoral pain syndrome.     

Hamstring length in patellofemoral pain syndrome

Objectives

To investigate whether there was a difference in hamstring length between patients with patellofemoral pain syndrome and healthy asymptomatic controls aged 18 to 35 years.

Design

A cross-sectional observational study measuring hamstring length in patients and asymptomatic controls.

Setting

Hospital physiotherapy department.

Participants

Two groups were tested; one group diagnosed with patellofemoral pain syndrome (mean age 27 years, n = 11, six males, five females) and one group of asymptomatic controls (mean age 25 years, n = 25, 13 males, 12 females).

Main outcome measures

Hamstring length was evaluated using the passive knee extension method to measure popliteal angle.

Results

The mean (standard deviation) values for hamstring length were 145.6 (8.7)° for patients with patellofemoral pain syndrome and 153.7 (10.1)° for the asymptomatic controls. The mean (95% confidence interval) difference between the groups was 8.0 (0.8 to 15.1)°, and analysis with a t-test revealed that this was statistically significant (P < 0.05).

Conclusions

This study found that patients with patellofemoral pain had shorter hamstring muscles than asymptomatic controls. It is not clear whether this is a cause or effect of the condition. Further research is suggested to study how hamstring length changes with rehabilitation, and the relationship with pain.     

Lumbopelvic manipulation in patients with patellofemoral pain syndrome

Abstract

Objectives: A recent clinical prediction rule (CPR) identified characteristics that may predict an immediate reduction in pain following lumbopelvic manipulation in patients with patellofemoral pain syndrome. The purpose of this single-arm cohort study was to replicate the proposed CPR in a different population and investigate changes in self-reported pain, hip range of motion, strength, and function immediately following lumbopelvic manipulation.

Methods: Forty-four subjects (63·6% female; mean age 27·4 years) met inclusion criteria. Hip internal rotation range of motion, lower extremity strength using a handheld dynamometer, and single/triple hop tests were assessed prior to and immediately following a spinal manipulation. A global rating of change questionnaire was administered after testing and telephonically at 1 week. Paired t-tests compared pre- and post-manipulation range of motion, strength, and hop test limb symmetry indices (α?=?0·05).

Results: Fifty-seven percent of subjects had a successful outcome measured by the numerical pain rating scale immediately following manipulation. Twenty-five of subjects experienced a successful outcome as measured by the global rating of change questionnaire at 1 week. No single individual or combination of predictor variables predicted a positive outcome immediately following the lumbopelvic manipulation (+likelihood ratio 0·7 with three of five predictor variables present). Statistically significant differences (P<0·05) were found in hip extension and abduction strength and hip internal rotation symmetry post-manipulation, but do not appear to be clinically meaningful.

Discussion: The previously identified CPR was not able to be replicated and no clinically meaningful changes in range of motion, strength, or function were apparent. Future research should focus on a comprehensive impairment-based treatment approach in patients with patellofemoral pain syndrome.     

Lumbopelvic manipulation in patients with patellofemoral pain syndrome

Objectives:

A recent clinical prediction rule (CPR) identified characteristics that may predict an immediate reduction in pain following lumbopelvic manipulation in patients with patellofemoral pain syndrome. The purpose of this single-arm cohort study was to replicate the proposed CPR in a different population and investigate changes in self-reported pain, hip range of motion, strength, and function immediately following lumbopelvic manipulation.

Methods:

Forty-four subjects (63·6% female; mean age 27·4 years) met inclusion criteria. Hip internal rotation range of motion, lower extremity strength using a handheld dynamometer, and single/triple hop tests were assessed prior to and immediately following a spinal manipulation. A global rating of change questionnaire was administered after testing and telephonically at 1 week. Paired t-tests compared pre- and post-manipulation range of motion, strength, and hop test limb symmetry indices (α = 0·05).

Results:

Fifty-seven percent of subjects had a successful outcome measured by the numerical pain rating scale immediately following manipulation. Twenty-five of subjects experienced a successful outcome as measured by the global rating of change questionnaire at 1 week. No single individual or combination of predictor variables predicted a positive outcome immediately following the lumbopelvic manipulation (+likelihood ratio 0·7 with three of five predictor variables present). Statistically significant differences (P<0·05) were found in hip extension and abduction strength and hip internal rotation symmetry post-manipulation, but do not appear to be clinically meaningful.

Discussion:

The previously identified CPR was not able to be replicated and no clinically meaningful changes in range of motion, strength, or function were apparent. Future research should focus on a comprehensive impairment-based treatment approach in patients with patellofemoral pain syndrome.     

Electromyographic biofeedback-controlled exercise versus conservative care for patellofemoral pain syndrome.

OBJECTIVE: To determine the effects of electromyographic biofeedback treatment in patients with patellofemoral pain syndrome. DESIGN: Randomized controlled trial. SETTING: A physical medicine and rehabilitation department in a research hospital of a university referral center. PATIENTS: Sixty patients with patellofemoral pain syndrome. Patients were randomly placed into 2 groups: biofeedback group (n = 30) and a control group (n = 30). INTERVENTION: The biofeedback group received electromyographic biofeedback training and a conventional exercise program, whereas the control group received a conventional exercise program only. MAIN OUTCOME MEASURES: Maximum and mean contraction values of the vastus medialis and the vastus lateralis muscles were assessed with the biofeedback device. Pain and functional status of the patients were measured by a visual analog scale (VAS) and the Functional Index Questionnaire (FIQ), respectively. RESULTS: Contraction values improved significantly at the end of the first month, compared with the pretreatment values in both groups. Mean contraction values in the biofeedback group of the vastus medialis muscles in all 3 monthly measurements, and the vastus lateralis muscles at the end of the first month, were significantly higher than those of the control group. Significant improvements were shown for both the VAS and the FIQ in both groups. Monthly follow-ups showed no VAS and FIQ differences between the groups. CONCLUSION: Electromyographic biofeedback treatment did not result in further clinical improvement when compared with a conventional exercise program in patients with patellofemoral pain syndrome.     

Clinical tests for differentiating between patients with and without patellofemoral pain syndrome

Patellofemoral pain syndrome (PFPS) is a very common knee condition with various aetiologies. Because of the nebulous factors of the syndrome, physiotherapists often find it difficult to assess and treat these patients. The aim of this study was to identify the clinical assessment tool that can differentiate PFPS patients from patients with other lower limb conditions. Fifty-two patients from the National Health System (26 with PFPS and 26 with other lower limb conditions) took part in this study. They underwent a series of strength, flexibility, and stress tests. Their pain levels were also recorded. The results showed that among the various clinical tests, only the hip flexion component of the Thomas test was able to differentiate between the two groups. In addition, the stress test showed that the PFPS group could not recover their gluteal muscle strength in the same way the group with the other lower limb conditions did. The Lower Extremity Functional Scale was found to be more able to differentiate between the two groups than the Anterior Knee Pain Scale. This study has shown that it is difficult to find specific clinical tests to diagnose PFPS. More research is needed in this important area.     

Efficacy of isokinetic exercise on functional capacity and pain in patellofemoral pain syndrome

OBJECTIVE: To assess the effect of an isokinetic exercise program on symptoms and functions of patients with patellofemoral pain syndrome. DESIGN: A total of 22 consecutive patients with the complaint of anterior knee pain who met the inclusion criteria were recruited to assess the efficacy of isokinetic exercise on functional capacity, isokinetic parameters, and pain scores in patients with patellofemoral pain syndrome. A total of 37 knees were examined. Six-meter hopping, three-step hopping, and single-limb hopping course tests were performed for each patient with the measurements of the Lysholm scale and visual analog scale. Tested parameters were peak torque, total work, average power, and endurance ratios. RESULTS: Statistical analyses revealed that at the end of the 6-wk treatment period, functional and isokinetic parameters improved significantly, as did pain scores. There was not statistically significant correlation between different groups of parameters. CONCLUSION: The isokinetic exercise treatment program used in this study prevented the extensor power loss due to patellofemoral pain syndrome, but the improvement in the functional capacity was not correlated with the gained power.     

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.     

Electromyographic fatigue characteristics of the quadriceps in patellofemoral pain syndrome

This study compared the fatigue characteristics of the vastus medialis oblique (VMO), vastus lateralis (VL) and rectus femoris (RF) muscles. Ten healthy subjects with 10 patients with patellofemoral pain syndrome (PFPS) performed an isometric leg press for 60 seconds at 60% MVIC with data collected using surface EMG. The power spectrum was analyzed and the extracted median frequency normalised to calculate a linear regression slope for each muscle. A repeated measures ANOVA revealed no significant differences, neither between the groups (P=0.592) nor the muscles (P=0.434). However, the slopes for the VMO and VL were different between the two groups with similar slopes for the RF. There was much larger variability of MF values in the PFPS group. The VMO:VL ratio calculated from these slopes for the healthy subjects was 1.17 and for the PFPS group was 1.78. These results may indicate unusual features in the fatigue indices of the quadriceps in PFPS.     

Outcomes of a weight-bearing rehabilitation program for patients diagnosed with patellofemoral pain syndrome

OBJECTIVE: To determine the effects of a weight-bearing rehabilitation program on quadriceps and gluteus medius electromyographic activity, pain, and function in subjects diagnosed with patellofemoral pain syndrome (PFPS). DESIGN: Pretest and posttest 6-week intervention study. SETTING: Musculoskeletal research laboratory. PARTICIPANTS: Fourteen subjects diagnosed with PFPS and 14 healthy control subjects volunteered to participate in this study. No subjects withdrew from the study because of adverse effects. INTERVENTION: Subjects diagnosed with PFPS participated in a 6-week rehabilitation program. The rehabilitation program consisted of weight-bearing exercises that focused on strengthening the quadriceps and hip abductor musculature. MAIN OUTCOME MEASURES: Electromyographic onsets of the vastus medialis oblique (VMO) and vastus lateralis and onset and duration of the gluteus medius were collected during a stair-stepping task that was performed during the pretest and posttest. A visual analog scale (VAS) and Functional Index Questionnaire (FIQ) were administered at pretest and posttest and each week of the intervention. RESULTS: Vastus lateralis and VMO onset timing differences (vastus lateralis electromyographic onset minus VMO electromyographic onset) and VAS and FIQ scores significantly improved for patients diagnosed with PFPS. Vastus lateralis and VMO onset timing in the PFPS group were significantly different from those in the control group at baseline and were not significantly different from the control group after the intervention. We did not find differences in gluteus medius onsets or duration of activity. CONCLUSIONS: Subjects diagnosed with PFPS responded favorably and quickly to a therapeutic exercise program that incorporated quadriceps and hip musculature strengthening. The efficacy of the therapeutic exercise program used in this study should be further investigated in a larger subject population.     

Psychometric evidence of self-reported questionnaires for patellofemoral pain syndrome: a systematic review

Abstract

Purpose: To conduct a systematic review of psychometric properties of self-reported questionnaires used to assess the level of symptoms and disability in individuals with patellofemoral pain syndrome (PFPS). Methods: A structured search was conducted in four databases (Medline, Embase, CINAHL, SportDiscus). A total of 24 studies about five different self-reported questionnaires were analyzed. A pair of independent raters extracted data on validity, reliability and responsiveness to change, and performed critical appraisal (0–100%). Results: Activities of Daily Living Scale (ADLS), Anterior Knee Pain Scale (AKPS), International Knee Documentation Committee (IKDC) and Lysholm Scale (LS) present excellent test–retest reliability (weighted average intraclass correlation coefficients [ICC]?>?0.80), whereas Functional Index Questionnaire (FIQ) is moderately reliable (ICC?=?0.61). Minimal detectable change is 8.3% for ADLS, 9.0% for AKPS, 19% for FIQ, 8.5% for IKDC and 30% for LS. ADLS, AKPS, IKDC and LS are highly responsive (effect size/standardized response mean >0.95) in individuals with PFPS, while FIQ is lowly responsive (effect size?=?0.49). Conclusion: Based on available evidence, ADLS presents the best psychometric properties and should be preferred when evaluating patients with PFPS. AKPS and IKDC are also adequate, while FIQ and LS are not recommended for individuals with PFPS.

• Implications for Rehabilitation

• While several questionnaires have been developed to assess symptoms and functional limitations caused by knee pain, their psychometric properties can vary depending on the condition presented by the patient.

• The Activities of Daily Living Scale of the Knee Outcome Survey should be preferred by clinicians when evaluating a patient with PFPS.

• The Anterior Knee Pain Scale and International Knee Documentation Committee Subjective knee evaluation are also adequate for use with this population.

• The Functional Index Questionnaire and Lysholm Scale are not recommended for PFPS.

     

Iliotibial band tightness and patellofemoral pain syndrome: a case-control study

Tight lateral structures have been implicated in subjects presenting with patellofemoral pain syndrome (PFPS). It has been proposed that a tight iliotibial band (ITB) through its attachment of the lateral retinaculum into the patella could cause lateral patella tracking, patella tilt and compression. Twelve subjects presenting with PFPS were compared with 12 matched control subjects. Hip adduction was measured using the Ober test in each subject as an indirect measure of ITB length. The mean values for hip adduction in the control group were 21.4 (+/-4.9) and 20.3 (+/-3.8) degrees in the left and right legs, respectively, and in the PFPS group, 17.3 (+/-6.1) and 14.9 (+/-4.2) degrees in the non-painful leg and painful leg, respectively. One way analysis of variance (ANOVA) revealed a highly significant difference between groups (F=4.485, p=0.008) and post-hoc analysis showed a significant difference between the painful leg in the PFPS group and the left and right legs in the control group, p=0.002 and 0.009, respectively. The results from this study show that subjects presenting with PFPS do have a tighter ITB. Future work should investigate this observation prospectively in order to determine whether a tight ITB is the cause or effect of PFPS.     

Electromyographic biofeedback[ndash ]controlled exercise versus conservative care for patellofemoral pain syndrome

Dursun N, Dursun E, Kili[ccedil] Z. Electromyographic biofeedback[ndash ]controlled exercise versus conservative care for patellofemoral pain syndrome. Arch Phys Med Rehabil 2001;82:1692-5. Objective: To determine the effects of electromyographic biofeedback treatment in patients with patellofemoral pain syndrome. Design: Randomized controlled trial. Setting: A physical medicine and rehabilitation department in a research hospital of a university referral center. Patients: Sixty patients with patellofemoral pain syndrome. Patients were randomly placed into 2 groups: biofeedback group (n = 30) and a control group (n = 30). Intervention: The biofeedback group received electromyographic biofeedback training and a conventional exercise program, whereas the control group received a conventional exercise program only. Main Outcome Measures: Maximum and mean contraction values of the vastus medialis and the vastus lateralis muscles were assessed with the biofeedback device. Pain and functional status of the patients were measured by a visual analog scale (VAS) and the Functional Index Questionnaire (FIQ), respectively. Results: Contraction values improved significantly at the end of the first month, compared with the pretreatment values in both groups. Mean contraction values in the biofeedback group of the vastus medialis muscles in all 3 monthly measurements, and the vastus lateralis muscles at the end of the first month, were significantly higher than those of the control group. Significant improvements were shown for both the VAS and the FIQ in both groups. Monthly follow-ups showed no VAS and FIQ differences between the groups. Conclusion: Electromyographic biofeedback treatment did not result in further clinical improvement when compared with a conventional exercise program in patients with patellofemoral pain syndrome. [copy ] 2001 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation     

Exercise lowers pain threshold in chronic fatigue syndrome

Post-exertional muscle pain is an important reason for disability in patients who are diagnosed to have Chronic Fatigue Syndrome (CFS). We compared changes in pain threshold in five CFS patients with five age and sex matched controls following graded exercise. Pain thresholds, measured in the skin web between thumb and index finger, increased in control subjects with exercise while it decreased in the CFS subjects. Increased perception of pain and/or fatigue after exercise may be indicative of a dysfunction of the central anti-nociceptive mechanism in CFS patients.     

Analysis of outcome measures used in the study of patellofemoral pain syndrome

Validation of evaluation methods is necessary in order to appropriately monitor Patellofemoral Pain Syndrome (PFPS) patients and to determine the effectiveness of treatment and prevention programs. The goal of this study was to investigate the psychometric properties of five evaluation methods: a functional index questionnaire (FIQ), visual analogue scales (VAS) for pain, a patellofemoral function scale (PFS), a step test and a subjective report of functional limitations. Measurements for each of the six components were taken on 56 PFPS patients participating in a randomized clinical trial, prior to and at one month following treatment. Modest test-retest reliability for the FIQ, VAS and step test were found. High internal consistency for the FIQ and modest internal consistency for the PFS were demonstrated. The VAS and FIQ were found to be good discriminators for measuring clinical change, while the step test was found to be reliable but poor at detecting clinical change. The PFS, which combines a number of evaluation areas into an index, demonstrated potential to detect clinical change, however, conclusions are limited as reliability testing was not performed.