Effect of intraarticular glycosaminoglycan polysulfate treatment on patellofemoral pain syndrome. A prospective, randomized double-blind trial comparing glycosaminoglycan polysulfate with placebo and quadriceps muscle exercises

Medical Interventions for Patellofemoral Pain and Patellofemoral Osteoarthritis: A Systematic Review

Patellofemoral pain (PFP) and patellofemoral osteoarthritis (PFOA) are common, persistent conditions that may lie along a pathological spectrum. While evidence supports exercise-therapy as a core treatment for PFP and PFOA, primary care physicians commonly prescribe medication, or refer for surgical consults in persistent cases. We conducted a systematic review of medical interventions (pharmaceutical, nutraceutical, and surgical) for PFP and PFOA to inform primary care decision making. Methods: Following protocol registration, we searched seven databases for randomized clinical trials of our target interventions for PFP and PFOA. Our primary outcome was pain. We assessed risk of bias, calculated standardized mean differences (SMDs) and determined the level of evidence for each intervention. Results: We included 14 publications investigating pharmaceutical or nutraceutical interventions, and eight publications investigating surgical interventions. Two randomized control trials (RCTs) provided moderate evidence of patellofemoral arthroplasty having similar pain outcomes compared to total knee arthroplasty in isolated PFOA, with SMDs ranging from −0.3 (95% CI −0.8, 0.2, Western Ontario McMaster Pain Subscale, 1 year post-surgery) to 0.3 (−0.1, 0.7, SF-36 Bodily Pain, 2 years post-surgery). Remaining studies provided, at most, limited evidence. No efficacy was demonstrated for oral nonsteroidal anti-inflammatories or arthroscopic surgery. Conclusions: Pharmaceutical and nutraceutical prescriptions, and surgical referrals are currently being made with little supporting evidence, with some interventions showing limited efficacy. This should be considered within the broader context of evidence supporting exercise-therapy as a core treatment for PFP and PFOA.

Selected Musculoskeletal Issues in Adolescents

Musculoskeletal care of the adolescent patient involves unique knowledge of their rapidly changing physical and psychological health. In this article, the importance of preventing early sports specialization is elucidated, and an encouragement of the safety and necessity of resistance training in adolescents is undertaken. It also explores two common conditions, one affecting the immature skeleton (apophysitis), and one affecting the improperly developed muscular system (patellofemoral syndrome), both of which are diagnosed clinically, and require little advanced imaging. Finally, a brief overview of relative energy deficiency in sport is given.

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.

Work-related outcomes in randomized, double blind, placebo-controlled trials in osteoarthritis - are they adequately reported in journal publications? A systematic review

Background

Osteoarthritis (OA) has a high prevalence in Western societies and can affect an individual's life in a number of domains, including work. In our experience, treatment trials on OA, however, rarely report work-related outcomes. Here we conducted a systematic review to assess the reporting of work-related outcomes in randomized, double blind, placebo-controlled trials in OA. Our systematic review also compared two search strategies for identifying eligible publications, one where work-related terms were included in the database search string (A) and one where this was not the case and work-related outcomes were identified by searches of full text Portable Document Formats (PDFs) (B). Search strategy A would conventionally be used and would only identify publications where work-related terms were mentioned in the title or abstract. Search strategy B presents the innovation of full text PDF searching and would identify publications were work-related terms were reported in the full text, regardless of whether they are mentioned in the title and abstract or not. We hypothesize that search strategy B identifies more relevant publications than search strategy A.

Methods

Electronic database searching was performed in Medline (Pubmed) from database inception to February 23, 2017 to identify peer-reviewed articles of randomized, double blind, placebo-controlled treatment trials in OA of the hand, hip, or knee, available as full-text PDFs. For search strategy A, search terms to identify work-related outcomes were included in the database search string, while search strategy B did not have these terms included in the database search string, but instead involved full text PDF searching. We included English language articles only and only those articles where searchable PDFs were available, to enable a comparison between search strategies A and B. Additionally, included studies also needed to report on pain intensity in relation to the work-related outcomes.

Results

Search strategy A yielded 50 hits combined for hand, hip or knee OA that mentioned some work-related concept in the title or abstract; 12 articles had to be excluded because they were not available as searchable PDFs. Screening of the remaining 38 articles resulted in only two articles that satisfied our inclusion criteria. Search strategy B yielded 986 hits, out of which 201 articles were excluded because searchable full text PDFs were not available. PDF full text searching and further screening resulted in 10 articles that were considered eligible for our review.

Conclusions

Work-related outcomes are rarely reported in journal publication on randomized, double blind, placebo-controlled trials of hand, hip or knee OA. Searching full text PDFs yields more eligible articles than searching titles and abstracts only.

Is there a role of pulsed electromagnetic fields in management of patellofemoral pain syndrome? Randomized controlled study at one year follow-up

Patellofemoral pain syndrome (PFPS) is a common cause of recurrent or chronic knee pain in young adults, generally located in the retropatellar region. Etiology is controversial and includes several factors, such as anatomical defects, muscular imbalance, or joint overuse. Good results have been reported with exercise therapy, including home exercise program (HEP). Joint inflammation with increase of pro-inflammatory cytokines levels in the synovial fluid might be seen especially when chondromalacia becomes evident. Biophysical stimulation with pulsed electromagnetic fields (PEMFs) has shown anti-inflammatory effects and anabolic chondrocyte activity. The purpose of this randomized controlled study was to evaluate if the combination of HEP with PEMFs was more effective than HEP alone in PFPS treatment. Thirty-one PFPS patients were enrolled in this study. All patients were instructed to train with HEP. Patients in the PEMFs group associated HEP with PEMFs. Function and pain were assessed with Victorian Institute of Sport Assessment score (VISA), Visual Analog Scale (VAS), and Feller's Patella Score at baseline at 2, 6, and 12 months of follow-up. Drug assumption was also recorded. Increase in VISA score was significantly higher in PEMFs group compared to controls at 6 and 12 months, as well as the increase in the Feller's Patella Score at 12 months. VAS score became significantly lower in the PEMFs group with respect to control group since 6 month follow-up. Pain reduction obtained with PEMFs enhanced practicing therapeutic exercises leading to a better recovery process; this is extremely important in addressing the expectations of young patients, who wish to return to sporting activities.

Evaluation of electromyographic biofeedback for the quadriceps femoris: a systematic review

OBJECTIVE

To critically review evidence for the effectiveness of electromyographic biofeedback (EMGB) of the quadriceps femoris muscle in treating various knee conditions.

DATA SOURCES

Databases used to locate randomized controlled trials included PubMed (1980-2010), Cumulative Index of Nursing and Allied Health Literature (CINAHL, 1995-2007), Web of Science (1986-2010), SPORTDiscus (1990-2007), and Physiotherapy Evidence Database (PEDro). Key words were knee and biofeedback.

STUDY SELECTION

The criteria for selection were clinical randomized controlled trials in which EMGB of the quadriceps femoris was used for various knee conditions of musculoskeletal origin. Trials were excluded because of research designs other than randomized controlled trials, articles published in a non-English language, inclusion of healthy research participants, inability to identify EMGB as the source of clinical improvement, and lack of pain, functional outcome, or quadriceps torque as outcome measures.

DATA EXTRACTION

Twenty specific data points were abstracted from each clinical trial under the broad categories of attributes of the patient and injury, treatment variables for the EMGB group, treatment variables for the control group, and attributes of the research design.

DATA SYNTHESIS

Eight trials yielded a total of 319 participants with patellofemoral pain syndrome (n = 86), anterior cruciate ligament reconstruction (n = 52), arthroscopic surgery (n = 91), or osteoarthritis (n = 90). The average methodologic score of the included studies was 4.6/10 based on PEDro criteria. Pooled analyses demonstrated heterogeneity of the included studies, rendering the interpretation of the pooled data inappropriate. The EMGB appeared to benefit short-term postsurgical pain or quadriceps strength in 3 of 4 postsurgical investigations but was ineffective for chronic knee conditions such as patellofemoral pain and osteoarthritis in all 4 studies. Because the findings are based on limited data, caution is warranted until more randomized controlled trials are conducted to support or refute the general trends observed in this report.

The non-operative treatment of anterior knee pain

Anterior knee pain is a common presenting complaint, and in many cases no identifiable cause can be found. In these circumstances it is commonly known as anterior knee pain syndrome or patellofemoral pain syndrome. The management for this condition is most commonly non-operative. Treatment strategies include physiotherapy, pharmacotherapy, orthoses and combinations of the above. There are many described methods in the literature with a wide spectrum of outcomes, which in itself is testimony to the lack of any generally accepted gold standard of care for these patients. It is thus unclear to the health care professional treating these patients which is the best treatment to offer. In this review we aim to summarise historical and most up to date literature on the subject and in so doing allow the health care professional pick whichever treatment strategy they feel most beneficial and also provide a guide for appropriate patient education.

Training program and additional electric muscle stimulation for patellofemoral pain syndrome: a pilot study

OBJECTIVES

To evaluate the beneficial effect of training in patients with patellofemoral pain syndrome (PFPS) and influence of additional electric muscle stimulation (EMS) of the knee extensor muscles.

DESIGN

A randomized clinical trial.

SETTING

Supervised physiotherapy (PT) training and home-based EMS.

PARTICIPANTS

Patients (N=38; 14 men, 24 women) with bilateral PFPS.

INTERVENTIONS

One group (PT) received supervised PT training for 12 weeks. The other received PT and EMS. The stimulation protocol was applied to the knee extensors for 20 minutes, 2 times daily, 5 times a week for 12 weeks at 40 Hz, with a pulse duration of .2 6ms, at 5 seconds on and 10 seconds off. Maximal tolerable stimulation intensity was up to 80 mA.

MAIN OUTCOME MEASURES

Patellofemoral pain assessment with visual analog scale during activities of daily life, Kujala patellofemoral score, and isometric strength measurement before and after 12 weeks treatment as well as after 1 year.

RESULTS

Thirty-six patients completed the 12-week follow-up. There was a statistically significant reduction of pain in both groups (PT group, P=.003; PT and EMS group, P<.001) and significant improvement of the Kujala score in both groups (PT group, P<.001; PT and EMS group, P<.001) after 12 weeks of treatment with improvement of function and reduction of pain at the 1-year follow-up. The difference between the 2 treatment groups was statistically not significant. We could not measure any significant change in isometric knee extensor strength in either group.

CONCLUSIONS

A supervised PT program can reduce pain and improve function in patients with PFPS. We did not detect a significant additional effect of EMS with the protocol described previously.

Electric muscle stimulation of the quadriceps in the treatment of patellofemoral pain

OBJECTIVE

To compare a commercially available electric muscle stimulation regimen with a novel form of stimulation for the rehabilitation of the quadriceps muscle, in patients with patellofemoral pain syndrome.

DESIGN

Double-blinded randomized trial with a parallel control group and stratified randomization.

SETTING

Home-based rehabilitation program assessed in research center.

PARTICIPANTS

Eighty patients (47 women, 33 men) with patellofemoral pain syndrome.

INTERVENTIONS

One group (EMPI) received 1 uniform constant frequency component of 35Hz. The other (EXPER) group received an experimental form of stimulation that contained 5 simultaneously delivered frequency components of 125, 83, 50, 2.5, and 2Hz. Stimulation was applied to the quadriceps muscles of the affected leg for 1 hour daily for 6 weeks, a total of 42 treatments.

MAIN OUTCOME MEASURES

Lower-limb isometric and isokinetic torque, quadriceps fatigue, knee flexion, patellar pain, a step test, quadriceps cross-sectional area, and Kujala patellofemoral score for pain before and after treatment.

RESULTS

Seventy-four patients (43 women, 31 men) completed the trial. Patients in both groups showed significant improvements in all outcomes (P<.05). No significant differences existed between the 2 stimulators in any outcome (P>.05) except for quadriceps cross-sectional area (P=.023).

CONCLUSIONS

One form of stimulation was just as efficacious as the other in improving subjective and objective measures.

Pharmacotherapy for patellofemoral pain syndrome

BACKGROUND

Patellofemoral pain syndrome (PFPS) is common among adolescents and young adults. It is characterised by pain behind or around the patella and crepitations, provoked by ascending or descending stairs, squatting, prolonged sitting with flexed knees, running and cycling. The symptoms impede function in daily activities or sports. Pharmacological treatments focus on reducing pain symptoms (non-steroidal anti-inflammatory drugs (NSAIDs), glucocorticosteroids), or restoring the assumed underlying pathology (compounds containing glucosamine to stimulate cartilage metabolism, anabolic steroids to increase bone density of the patella and build up supporting muscles). In studies, drugs are usually applied in addition to exercises aimed at building up supporting musculature.

OBJECTIVES

This review aims to summarise the evidence of effectiveness of pharmacotherapy in reducing anterior knee pain and improving knee function in people with PFPS.

SEARCH STRATEGY

We searched the Cochrane Musculoskeletal Injuries Group and Cochrane Rehabilitation and Related Therapies Field trials registers, the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 4, 2003), PEDro (up to January 2004), MEDLINE (1966 to January 2004), EMBASE (1988 to January 2004), and CINAHL (1982 to January 2004).

SELECTION CRITERIA

Controlled trials (randomised or not) comparing pharmacotherapy with placebo, different types of pharmacotherapy, or pharmacotherapy to other therapies for people with PFPS.

DATA COLLECTION AND ANALYSIS

The literature search yielded 780 publications. Eight trials were included, of which three were of high quality. Data were analysed qualitatively using best evidence synthesis, because meta-analysis was impeded by differences in route of administration of drugs, care programs and outcome measures.

MAIN RESULTS

Four trials (163 participants) studied the effect of NSAIDs. Aspirin compared to placebo in a high quality trial produced no significant differences in clinical symptoms and signs. Naproxen produced significant short term pain reduction when compared to placebo, but not when compared to diflunisal. Laser therapy to stimulate blood flow in tender areas led to more satisfied participants than tenoxicam, though not significantly. Two high quality RCTs (84 participants) studied the effect of glycosaminoglycan polysulphate (GAGPS). Twelve intramuscular injections in six weeks led to significantly more participants with a good overall therapeutic effect after one year, and to significantly better pain reduction during one of two activities. Five weekly intra-articular injections of GAGPS and lidocaine were compared with intra-articular injections of saline and lidocaine or no injections, all with concurrent quadriceps training. Injected participants showed better function after six weeks, though only the difference between GAGPS injected participants and non-injected participants was significant. The differences had disappeared after one year. One trial (43 participants) found that intramuscular injections of the anabolic steroid nandrolone phenylpropionate significantly improved both pain and function compared to placebo injections.

REVIEWERS' CONCLUSIONS

There is only limited evidence for the effectiveness of NSAIDs for short term pain reduction in PFPS. The evidence for the effect of glycosaminoglycan polysulphate is conflicting and merits further investigation. The anabolic steroid nandrolone may be effective, but is too controversial for treatment of PFPS.

Systematic review of the quality of randomized controlled trials for patellofemoral pain syndrome

STUDY DESIGN

Systematic review of the literature.

OBJECTIVES

To develop a grading scale to judge the quality of randomized clinical trials (RCTs) and conduct a systematic review of the published RCTs that assess nonoperative treatments for patellofemoral pain syndrome (PFPS).

BACKGROUND

Systematic reviews of the quality and usefulness of clinical trials allow for efficient synthesis and dissemination of the literature, which should facilitate clinicians' efforts to incorporate principles of evidence-based practice in the clinical decision-making process.

METHODS AND MEASURES

Using a scale based on criteria in the Cochrane Collaboration Handbook, we sought to critically appraise the methodology used in RCTs related to the nonoperative management of PFPS, synthesize and interpret our results, and report our findings in a user-friendly fashion. A scale to assess the methodological quality of trials was designed and pilot tested for its content and reliability. Published RCTs identified during a literature search were then selected and rated by 6 raters. We used predefined cutoff scores to identify specific weaknesses in the clinical research process that need to be improved in future clinical trials.

RESULTS

The quality scale we developed was demonstrated to be sufficiently reliable to warrant interpretation of the reviewers' findings. The percentage of trials that met a minimum level of quality for each specific criterion ranged from a low of 25% for the adequacy of the description of the randomization procedure to a high of 95% for the description and standardization of the intervention.

CONCLUSIONS

Based on the results of trials exhibiting a sufficient level of quality, treatments that were effective in decreasing pain and improving function in patients with PFPS were acupuncture, quadriceps strengthening, the use of a resistive brace, and the combination of exercises with patellar taping and biofeedback. The use of soft foot orthotics in patients with excessive foot pronation appeared useful in decreasing pain. In addition, at a short-term follow-up, patients who received exercise programs were discharged earlier from physical therapy. Unfortunately, most RCTs reviewed contained qualitative flaws that bring the validity of the results into question, thus diminishing the ability to generalize the results to clinical practice. These flaws were primarily in the areas of randomization procedures, duration of follow-up, control of cointerventions, assurance of blinding, accountability and proper analysis of dropouts, number of subjects, and the relevance of outcomes. Also, given the limited number of high-quality clinical trials, recommendations about supporting or refuting specific treatment approaches may be premature and can only be made with caution.

Physical therapy for patellofemoral pain: a randomized, double-blinded, placebo-controlled trial

BACKGROUND

Although physical therapy forms the mainstay of nonoperative management for patellofemoral pain, its efficacy has not been established.

HYPOTHESIS

Significantly more pain relief will be achieved from a 6-week regimen of physical therapy than from placebo treatment.

STUDY DESIGN

Multicenter, randomized, double-blinded, placebo-controlled trial.

METHODS

Seventy-one subjects, 40 years of age or younger with patellofemoral pain of 1 month or longer, were randomly allocated to a physical therapy or placebo group. A standardized treatment program consisted of six treatment sessions, once weekly. Physical therapy included quadriceps muscle retraining, patellofemoral joint mobilization, and patellar taping, and daily home exercises. The placebo treatment consisted of sham ultrasound, light application of a nontherapeutic gel, and placebo taping.

RESULTS

Sixty-seven participants completed the trial. The physical therapy group (N = 33) demonstrated significantly greater reduction in the scores for average pain, worst pain, and disability than did the placebo group (N = 34).

CONCLUSIONS

A six-treatment, 6-week physical therapy regimen is efficacious for alleviation of patellofemoral pain.

Therapeutic patellar taping changes the timing of vasti muscle activation in people with patellofemoral pain syndrome

OBJECTIVE

To examine the effect of the application of tape over the patella on the onset of electromyographic (EMG) activity of vastus medialis obliquus (VMO) relative to vastus lateralis (VL) in participants with and without patellofemoral pain syndrome (PFPS).

DESIGN

Randomised within subject.

SETTINGS

University laboratory.

PARTICIPANTS

Ten participants with PFPS and 12 asymptomatic controls.

INTERVENTIONS

Three experimental taping conditions: no tape, therapeutic tape, and placebo tape.

MAIN OUTCOME MEASURES

Electromyographic onset of VMO and VL assessed during the concentric and eccentric phases of a stair stepping task.

RESULTS

When participants with PFPS completed the stair stepping task, the application of therapeutic patellar tape was found to alter the temporal characteristics of VMO and VL activation, whereas placebo tape had no effect. In contrast, there was no change in the EMG onset of VMO and VL with the application of placebo or therapeutic tape to the knee in the asymptomatic participants.

CONCLUSIONS

These data support the use of patellar taping as an adjunct to rehabilitation in people with PFPS.

Altered vastii recruitment when people with patellofemoral pain syndrome complete a postural task

OBJECTIVE

To investigate the recruitment of the vastus medialis obliquus (VMO) and vastus lateralis during voluntary tasks that challenge the stability of the knee and to evaluate whether there is a change in the coordination of the postural response by the central nervous system in subjects with patellofemoral pain syndrome (PFPS).

DESIGN

Cross-sectional.

SETTING

University laboratory in Australia.

PARTICIPANTS

Thirty-seven subjects with PFPS and 37 asymptomatic sex-matched controls.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Recordings of electromyographic activity of the VMO, vastus lateralis, tibialis anterior, and soleus were made by using surface electrodes. Subjects rose onto their toes (rise task) or rocked back on their heels (rock task) in a visual choice-reaction time task. Electromyographic onsets were determined by using a computer algorithm and were verified visually.

RESULTS

Our results confirm that, in asymptomatic subjects, contraction of the VMO and vastus lateralis occurs as part of the feed-forward postural response associated with ankle movements in standing, and the contraction of these separate heads of the quadriceps group occurs simultaneously. However, when subjects with PFPS perform identical tasks, the electromyographic onset of the vastus lateralis occurs before that of the VMO.

CONCLUSION

These findings indicate a difference in motor control in subjects with PFPS. They also support the hypothesized relation between changes in the timing of activity of the vastii and PFPS and provide the theoretic rationale to support physiotherapy treatment commonly used in the management of PFPS.

Anterior knee pain after intramedullary nailing of fractures of the tibial shaft. A prospective, randomized study comparing two different nail-insertion techniques

BACKGROUND

Anterior knee pain is the most common complication after intramedullary nailing of the tibia. Dissection of the patellar tendon and its sheath during nailing is thought to be a contributing cause of chronic anterior knee pain. The purpose of this prospective, randomized study was to assess whether the prevalence or the intensity of anterior knee pain following intramedullary nailing of a tibial shaft fracture is reduced by the use of a paratendinous incision for the nail entry portal.

METHODS

Fifty patients with a tibial shaft fracture requiring intramedullary nailing were randomized equally to treatment with paratendinous or transtendinous nailing. Twenty-one patients from both study groups were followed for an average of three years after nailing. After fracture union, all but two patients had elective nail removal through the same surgical approach as was used for the nailing. At the follow-up evaluation, the patients used visual analog scales to report their level of anterior knee pain and the impairment caused by that pain. The scales described by Lysholm and Gillquist and by Tegner et al., the Iowa knee scoring system, and simple functional tests were used to quantitate the functional results. Isokinetic thigh-muscle strength was also measured.

RESULTS

Fourteen (67%) of the twenty-one patients treated with transtendinous nailing reported anterior knee pain at the final evaluation. Of these fourteen patients, thirteen were mildly to severely impaired by the pain. Fifteen (71%) of the twenty-one patients treated with paratendinous nailing reported anterior knee pain, and ten of the fifteen were impaired by the pain. The Lysholm, Tegner, and Iowa knee scoring systems; muscle-strength measurements; and functional tests showed no significant differences between the two groups.

CONCLUSION

Compared with a transpatellar tendon approach, a paratendinous approach for nail insertion does not reduce the prevalence of chronic anterior knee pain or functional impairment by a clinically relevant amount after intramedullary nailing of a tibial shaft fracture.

Intrinsic risk factors for the development of patellar tendinitis in an athletic population. A two-year prospective study

Retrospective studies have suggested various factors that might cause a disposition to develop patellar tendinitis, but no prospective data exist to determine any relationships. The purpose of this study was to determine the intrinsic risk factors for the development of patellar tendinitis in an athletic population. Before the study, 138 male and female students of physical education were evaluated for anthropometric variables, leg alignment characteristics, and muscle tightness and strength parameters. During the 2-year study, 19 of the 138 students developed patellar tendinitis. In all cases the diagnosis was confirmed by the presence of a hypoechogenic nodular lesion in the proximal region of the patellar tendon. Univariate and stepwise discriminant function analyses were performed comparing the various measurements. These analyses revealed that the only significant determining factor was muscular flexibility, with the patellar tendinitis patients being less flexible in the quadriceps and hamstring muscles (P < 0.05). The results of this study demonstrate that lower flexibility of the quadriceps and hamstring muscles may contribute to the development of patellar tendinitis in an athletic population. Therefore, the prevention of this condition in athletes should be focused on screening for and treating poor quadriceps and hamstring muscle flexibility.

Delayed onset of electromyographic activity of vastus medialis obliquus relative to vastus lateralis in subjects with patellofemoral pain syndrome

OBJECTIVE

To determine whether electromyographic (EMG) onsets of vastus medialis obliquus (VMO) and vastus lateralis (VL) are altered in the presence of patellofemoral pain syndrome (PFPS) during the functional task of stair stepping.

DESIGN

Cross-sectional.

SETTING

University laboratory.

PATIENTS

Thirty-three subjects with PFPS and 33 asymptomatic controls.

INTERVENTIONS

Subjects ascended and descended a set of stairs-2 steps, each 20-cm high-at usual stair-stepping pace. EMG readings of VMO and VL taken on middle stair during step up (concentric contraction) and step down (eccentric contraction).

MAIN OUTCOME MEASURES

Relative difference in onset of surface EMG activity of VMO compared with VL during a stair-stepping task. EMG onsets were determined by using a computer algorithm and were verified visually.

RESULTS

In the PFPS population, the EMG onset of VL occurred before that of VMO in both the step up and step down phases of the stair-stepping task (p <.05). In contrast, no such differences occurred in the onsets of EMG activity of VMO and VL in either phase of the task for the control subjects.

CONCLUSION

This finding supports the hypothesized relationship between changes in the timing of activity of the vastimuscles and PFPS. This finding provides theoretical rationale to support physiotherapy treatment commonly used in the management of PFPS.

Open versus closed kinetic chain exercises for patellofemoral pain. A prospective, randomized study

The goal of this prospective study was to evaluate the efficacy of open versus closed kinetic chain exercises in the nonoperative management of patellofemoral pain. Sixty patients were randomized into a 5-week program that consisted of only closed kinetic chain exercises or only open kinetic chain exercises. Muscle characteristics, subjective symptoms, and functional performance were evaluated in this study at the time of the initial physical examination, at the end of the treatment period, and 3 months later. Both groups experienced a statistically significant decrease in pain and an increase in functional performance. This study shows that both open and closed kinetic chain exercise programs lead to an improved subjective and clinical outcome in patients with anterior knee pain. The few significantly better functional results for some of the tested parameters in the closed kinetic chain group suggest that this type of treatment is a little more effective than the open kinetic chain program in the treatment of these patients.

Patellofemoral pain syndrome in the female athlete

Although PFS will continue to be a therapeutic challenge, the prognosis for most female athletes is good, especially if they are motivated and compliant with their treatment program. Particularly in women, care should be taken to avoid placing too much emphasis on biomechanical variants that may not be clinically significant or correctable because such findings can reinforce a feeling that "nothing can be done." In many cases, muscle dysfunction and repetitive loading of the patellofemoral joint rather than fixed biomechanical factors contribute to the development of PFS. Nonetheless, the importance of a detailed biomechanical assessment on physical examination must not be neglected, particularly in athletes who are not improving with conservative treatment and who may become surgical candidates. A practical initial treatment program for most athletes with nontraumatic PFS begins with relative rest, quadriceps strengthening, and stretching of tight myotendinous units. The introduction of NSAIDs, orthoses, taping, knee sleeves, and more specific rehabilitative exercises should be an individualized decision based on physical findings, past treatment results, and athletic expectations. Surgical referral should be considered in cases of PFS or patellar instability refractory to prolonged maximal nonoperative treatment.

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.

An outcome study of chronic patellofemoral pain syndrome. Seven-year follow-up of patients in a randomized, controlled trial

BACKGROUND

We determined prospectively the long-term outcomes of nonoperative treatment of chronic patellofemoral pain syndrome.

METHODS

Of forty-nine patients in a prospective, randomized, double-blind study of unilateral chronic patellofemoral pain syndrome in the knee, forty-five were reexamined seven years after the initial trial of treatment. In the earlier trial, the short-term (six-month) effects of intra-articular injections of glycosaminoglycan polysulfate combined with intensive quadriceps-muscle exercises were compared with those of injections of a placebo combined with exercises and with those of exercises alone. At seven years, the follow-up consisted of standardized subjective, functional, and clinical assessments and muscle-strength measurements as well as magnetic resonance imaging, radiography, and bone-densitometry measurements of the knee.

RESULTS

At six months, complete subjective, functional, and clinical recovery had occurred in almost three-fourths of the patients and, with the numbers available for study, neither significant nor clinically important differences among the three initial treatment groups were detected. The subjective and functional parameters showed few changes between six months and seven years; almost three-fourths of the patients still had full subjective and functional recovery at the time of the latest follow-up. However, according to the physician's clinical evaluation, the number of patients who had no symptoms on the patellar compression and apprehension tests decreased over time, from forty-two (93 percent) and forty (89 percent) of forty-five patients at six months to thirty (67 percent) and thirty-one (69 percent) at seven years; these changes were significant (p = 0.002 and p = 0.023, respectively). The number of patients who had crepitation on the patellar compression test increased over time, from twenty-six (58 percent) at six months to thirty-six (80 percent) at seven years (p = 0.021). The physician's overall assessment showed a similar trend, with thirty-four patients (76 percent) having had complete recovery at six months compared with thirty (67 percent) at seven years; however, with the numbers available, this change was not significant (p = 0.420). Magnetic resonance imaging, performed for thirty-seven patients, revealed no abnormalities in twenty-four (65 percent), mild abnormalities in four (11 percent), moderate abnormalities (a 25 to 75 percent decrease in the thickness of the cartilage) in seven (19 percent), and overt patellofemoral osteoarthritis in two (5 percent) at seven years.

CONCLUSIONS

The seven-year overall outcome was good in approximately two-thirds of the patients. However, the remaining patients still had symptoms or objective signs of a patellofemoral abnormality.

Which factors predict the long-term outcome in chronic patellofemoral pain syndrome? A 7-yr prospective follow-up study

PURPOSE

The aim of this prospective study was to determine which factors predict the long-term (7-yr) outcome of conservative treatment of chronic patellofemoral pain syndrome.

METHODS

The general predictors registered were age, gender, body composition, athletic activity, duration of symptoms, and follow-up time. The remaining 13 predictors were clinical or radiological measurements of the knee joint. In 45 consecutive patients, these predictors were measured at the beginning of the 6-wk treatment protocol (rest, NSAID, and intense isometric quadriceps exercises) and at the end of the follow-up. The outcome criteria were the 100-mm Visual Analog Scale (VAS) pain score, and the Lysholm and Tegner functional knee scores.

RESULTS

The extension strength of the affected knee was a significant predictor of the outcome scores (Lysholm score: r = 0.37, P < 0.05, and the Tegner score: r = 0.39, P < 0.01): the smaller the strength difference between the affected and unaffected knee, the better the outcome. In a multiple stepwise regression analysis, the variables pain in the patella apprehension test, patella crepitation at baseline and at follow-up, bilateral symptoms developed during the follow-up, and patient's age and height were also independent predictors of the final outcome and could together account 60% for the variation seen in the Lysholm score and 52% in the Tegner score, respectively. Neither the radiologic nor the magnetic resonance imaging changes at the affected knee had a clear association with the 7-yr outcome.

CONCLUSIONS

The results of the current and our previous (15) observations support the concept that restoration of good quadriceps strength and function to the affected extremity is important for good recovery of the patient. In addition, negative findings in the clinical tests of patellar pain and crepitation, nonappearance of bilateral symptoms during the follow-up, low body height, and young age are associated with good long-term outcome.

Nonoperative treatment for patellofemoral pain

Patellofemoral pain, often called patellofemoral stress syndrome or patellofemoral joint dysfunction, is a commonly seen knee pain syndrome in patients of all ages. It is often a frustrating problem for both the patient and the clinician, as the source of pain can be elusive, making treatment choices difficult. Strategies have been proposed based upon potential sources of pain, including both operative techniques as well as conservative management. Current nonoperative treatment strategies and techniques in the treatment of patellofemoral pain are reviewed. Recommendations and criteria for progression of rehabilitation and suggestions for future research regarding patellofemoral pain are suggested.

Intra-articular therapy in osteoarthritis

Although intra-articular therapy is widely used in the treatment of osteoarthritis (OA), those controlled clinical trials which include placebo groups suggest that there is little to be gained over joint aspiration alone, or even over a simple needle prick. Glucocorticoids may however offer a small additional symptom benefit over one or two weeks. Viscosupplementation may offer a slightly longer benefit. Intra-articular radiotherapy probably confers no benefit. Serious adverse effects are rare but local effects may occur in up to 10% of patients treated with viscosupplements. Future research should always include a placebo group in clinical studies, should clarify the possible benefits of viscosupplementation and should include in vitro work to consider the biological basis for possible actions of intra-articular therapy.

Patellofemoral pain syndrome. A critical review of the clinical trials on nonoperative therapy

Many therapies have been advocated for treating patellofemoral pain, which suggests little consensus on optimal treatment. We reviewed the high-quality evidence for successful treatment of patellofemoral syndrome based on successful outcome information. To achieve this goal, we undertook a systematic search and critical appraisal of the literature on patellofemoral pain syndrome. Our definition of patellofemoral pain syndrome was broad and included patients with cartilage damage. We found five randomized controlled trials and some follow-up studies. The prognoses for most new cases of patellofemoral pain syndrome are good, although a proportion of patients with this syndrome will have persistent symptoms. Quadriceps muscle exercises were effective in treating this condition, and knee braces were not. Both prostheses and intramuscular glycosaminoglycan polysulfate had encouraging results for patients; however, these results need confirmation. There were many studies of biomechanics, which indicates that there is an assumption that an alteration of abnormal biomechanics would result in clinical benefit. Studies are needed that place more emphasis on the therapeutic benefit. There is limited evidence on which to base therapy, and there needs to be more high-quality research. Studies need to be longer, account for factors that predispose the patients, and have a more standardized means of assessing outcomes.