Electrical stimulation of vastus medialis and stretching of lateral thigh muscles in patients with patello-femoral symptoms

[Isolated Patellofemoral Osteoarthritis]

Isolated patellofemoral osteoarthritis is a complex pathology. It occurs frequently in women over 40 years and leads to a high degree of suffering. The causes of femoropatellar degeneration are manifold and require stage-specific therapy. This is very challenging for the treating physician. This article is intended to provide a structured overview of the symptoms, diagnostics and stage-specific therapy of patellofemoral osteoarthritis.

The Influence of the Q-Angle and Muscle Strength on Idiopathic Anterior Knee Pain in Adolescents

Background and Objectives: Idiopathic anterior knee pain is a common condition in adolescents and is mostly of unknown cause. The aim of this study was to examine the influence of the Q-angle and muscle strength on idiopathic anterior knee pain. Materials and Methods: Seventy-one adolescents (41 females and 30 males) diagnosed with anterior knee pain were included in this prospective study. The extensor strength in the knee joint and the Q-angle were monitored. The healthy extremity was used as a control. The Student's paired sample t-test was applied for testing the difference. Statistical significance was set at 0.05. Results: There was no statistically significant difference in the Q-angle value between the idiopathic AKP and the healthy extremity (p > 0.05) within the entire sample. A statistically significant higher Q-angle of the idiopathic AKP knee (p < 0.05) was obtained in the female subgroup. No statistically significant difference (p > 0.05) was found in the male subgroup. Within the male subgroup, the strength of the extensors within the knee joint of the healthy extremity had statistically significant higher values than the strength of these muscles in the affected extremity (p < 0.05). Conclusion: A greater Q-angle is a risk factor linked to anterior knee pain within the female population. Decreased muscle strength of knee joint extensors is a risk factor linked to anterior knee pain in both sex subgroups.

Improvement of Pain and Function by Using Botulinum Toxin Type A Injection in Patients with an Osteoarthritic Knee with Patellar Malalignment: An Electromyographic Study

Objective: To determine the pain and electromyographic (EMG) amplitude ratio of the vastus medialis oblique (VMO) to the vastus lateralis (VL) after botulinum toxin type A (BTA) was injected in the bilateral osteoarthritic knee of patients with patellar malalignment for analysis. Material and methods: A total of fifteen patients were recruited; the more symptomatic knee of each patient received a BTA injection (BTA side). The other set of patients were left untreated. In all, fifteen healthy participants comprised the control group. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and numeric rating scale (NRS) for pain were assessed. The EMG amplitude of VL and VMO activity was recorded using an isokinetic dynamometer and synchronized using the BIOPAC MP100. The data were collected before and at 4, 8, and 12 weeks post−BTA injection. Results: The EMG ratios of the patient group were lower than those of the control group at all testing velocities (p < 0.05). The VMO/VL ratio improved significantly on the BTA side only. The VMO/VL ratios on the BTA side were higher than those on the untreated side (p < 0.05). Knee pain decreased significantly after the BTA injection. The EMG ratios were negatively correlated with the NRS and WOMAC scores. Conclusion: BTA injection effectively reduces knee pain and restores the EMG ratio between the VMO and VL.

A Novel Mobile App-Based Neuromuscular Electrical Stimulation Therapy for Improvement of Knee Pain, Stiffness, and Function in Knee Osteoarthritis: A Randomized Trial

Background

Knee osteoarthritis (OA) is a widespread and debilitating disease that continues to plague patients. Over the past decade, neuromuscular electrical stimulation (NMES) therapy has shown promise in alleviating knee OA-related symptoms. This study sought to evaluate the efficacy and safety of a home-based NMES therapy for reduction of pain, stiffness, and function associated with knee OA.

Material and methods

A randomized, sham-controlled, double-blind, multicenter trial was conducted with 12-week follow-up in 156 knee OA patients receiving either home-based NMES therapy or a modified low-voltage NMES therapy. Outcome measures including knee pain, stiffness, and functionality were collected at baseline through week 12 after the therapy. The primary endpoint was the percentage change from baseline (PCFB) in the Visual Analog Scale (VAS) pain for a patient-nominated physical activity. Secondary endpoints included VAS for general knee pain, Western Ontario and McMaster Universities Osteoarthritis Index, Knee Injury and Osteoarthritis Outcome Score Joint Replacement, and isometric quadriceps strength test.

Results

A clinically meaningful reduction for VAS Nominated Activity was higher in the per-protocol treatment-compliant NMES group than that in the sham low-voltage NMES group at week 12 (PCFB of 42.8% vs 38.6%, P = .562). This was similarly true for the Western Ontario and McMaster Universities Osteoarthritis Index pain subscale (PCFBs of 36.8% vs 26.6%, P = .038). Similar trends and reductions of pain were observed for VAS General, Knee Injury and Osteoarthritis Outcome Score Joint Replacement Pain subscale, and isometric quadriceps strength.

Conclusion

Home-based NMES treatment resulted in a clinically meaningful reduction of knee pain, stiffness, and knee functional improvements at week 12 compared with sham NMES treatment.

Use of home neuromuscular electrical stimulation in the first 6 weeks improves function and reduces pain after primary total knee arthroplasty: a matched comparison

Background

The use of neuromuscular electrical stimulation (NMES) after total knee arthroplasty (TKA) has been demonstrated to facilitate quadriceps muscle recovery and to reduce pain. However, to our knowledge, this therapeutic modality has not been directly tested in patients who receive muscle stimulators for home use immediately after surgery. Therefore, the purpose of this study was to assess the effect of NMES use at home in addition to standard therapy program in patients after primary TKA surgery, and to compare the early functional results to a matching group of post TKA patients who did not receive home NMES units.

Methods

A total of 41 patients scheduled for a primary TKA during April 1^st, 2017 to January 31^st, 2018 were identified as being eligible for the study. There were 15 patients deemed ineligible to be part of the study, resulting in 26 patients who were fitted either 1 week before or within 1 week of surgery a home NMES device. The device was controlled by a smart phone. Patients were asked to use the NMES device daily for 20 minutes, 3 times a day, for 6 weeks after surgery. As their ability to activate their quadriceps muscle improved, patients were encouraged to increase their exercise regimens. The NMES patients were compared to a matched cohort of 26 patients who had a TKA performed between June 1^st, 2015 and July 31^st, 2016, but did not receive home an NMES device. Comparative outcomes included: timed up and go (TUG) test, single limb stance (SLS) time, time to ascend and descend one flight of stairs, quadriceps lag, active and passive range of motion (ROM), 2-minute walking distance, and pain rating on a visual analog scale (VAS). A P value of 0.05 was set as the threshold for statistical significance for the matched comparison.

Results

Patients in the home NMES had significantly better scores for quadriceps lag (P<0.001), TUG (P<0.001), time to ascend and descend one flight of stairs (P=0.001), SLS time (P<0.001). They also experienced significantly lower resting pain (P<0.001) and lower worst reported pain scores (P<0.001) compared to the control cohort. Additionally, there were a higher percentage of patients in the control cohort that could not use stairs reciprocally compared to the home NMES group (53.85% vs. 23.08%). Furthermore, passive range of motion for flexion was statistically better in the home NMES group (P=0.037).

Conclusions

This matched comparison of primary TKA patients demonstrated significant pain reductions both at rest and lower worst reported pain scores and improved function with use of the home-based NMES units for the sub-acute phase of recovery. Patients walked longer distances safely as shown by improvements in TUG, quadriceps lag, and single limb support time. Larger proportions of patients in home NMES group were able to negotiate stairs reciprocally and faster than the matched control group. These findings may have important economic and functional implications for the post-operative care of TKA patient.

Neuromuscular electrical stimulation (NMES) for patellofemoral pain syndrome

BACKGROUND

Patellofemoral pain syndrome, now generally referred to as patellofemoral pain (PFP), is one of the most common orthopaedic disorders, characterised by pain in the anterior or retropatellar knee region. Neuromuscular electrical stimulation (NMES) has been proposed generally as a complementary treatment, associated with other interventions such as exercise, or as a single treatment to increase muscle force, reduce knee pain, and improve function.

OBJECTIVES

To assess the effects (benefits and harms) of neuromuscular electrical stimulation for people with patellofemoral pain.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PEDro, CINAHL, SPORTDiscus, AMED, LILACS, trial registers, conference abstracts, and reference lists. We carried out the search in May 2017.

SELECTION CRITERIA

We included randomised controlled clinical trials that evaluated the use of NMES for people with PFP.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the process of study selection, data extraction, and 'Risk of bias' assessment in duplicate. The primary outcomes were knee pain, knee function, and adverse events. The timing of outcome measurements was up to three months (short term), three to 12 months (medium term), and 12 months and above from trial entry (long term). We calculated risk ratios for dichotomous data and mean differences or standardised mean differences for continuous data. Where appropriate, we pooled data using the fixed-effect model.

MAIN RESULTS

We included eight randomised clinical trials, reporting results for 345 participants with PFP. The mean ages of trial populations ranged from 25 to 43 years, and the majority (53% to 100%) of participants were female. There was a wide duration of symptoms, with the minimum duration of symptoms for trial inclusion ranging from one to six months. In addition to the study inclusion criteria, studies varied widely in the characteristics of the NMES and its application, and associated co-interventions. We assessed all trials as at high risk of bias in at least one domain, particularly blinding and incomplete outcome data. The results of a laboratory-based trial reporting knee pain immediately after a single 15-minute session of NMES are not reported here as these are of questionable clinical relevance. The seven remaining trials provided evidence for three comparisons. We assessed the overall quality of the evidence, using GRADE, for all primary outcomes for all comparisons as very low, thus we are very unsure of the findings.Four studies compared NMES plus exercise versus exercise alone. Patellar taping was applied as well as exercise to all participants of one study, and patellar taping and ice were also applied in another study. Each trial tested a different multiple-session NMES programme. Pooled data from three studies (118 participants) provided very low-quality evidence that NMES is associated with reduced pain at the end of treatment (ranging from 3 to 12 weeks): mean difference -1.63, 95% confidence interval (CI) -2.23 to -1.02; visual analogue scale (VAS) 0 to 10; higher scores = worse pain. However, this result may not be clinically relevant since the minimal clinically important difference for VAS during activities (1.5 to 2.0, out of 10 points) lies within the 95% CI. We found very low-quality evidence from pooled data from two trials of little effect of NMES on knee function, as measured by two knee function rating systems. We found inconclusive and very low-quality evidence from one trial (29 participants) of little effect of NMES on pain and function at one-year follow-up. None of the four trials reported on adverse effects of treatment.One study (94 participants) compared NMES, applied four hours per day on a daily basis for four weeks, with two types of exercises (isometric and isokinetic). The study did not report on knee pain or adverse events. The study provided very low-quality evidence of no important difference between the two groups in knee function at the end of the four-week treatment. Of note is the potentially onerous NMES schedule in this study, which does not correspond to that typically used in clinical practice.Two studies compared different types of NMES. Simultaneously delivered high-low frequencies NMES was compared with sequentially delivered high-low frequencies NMES in one trial (14 participants) and with fixed frequency NMES in the second trial (64 participants). The studies provided very low-quality evidence of no important differences at the end of the six-week treatment programme between the simultaneous frequencies NMES and the two other NMES programmes in overall knee pain, knee function, or in quadriceps fatigue (an adverse event).

AUTHORS' CONCLUSIONS

This review found insufficient and inconclusive evidence from randomised controlled trials to inform on the role of NMES for treating people with PFP in current clinical practice. The very low-quality evidence available means that we are uncertain whether or not a multiple-session programme of NMES combined with exercise over several weeks versus exercise alone results in clinically important differences in knee pain and function at the end of the treatment period or at one year. There were no data on adverse effects such as muscle fatigue and discomfort. High-quality randomised clinical trials are needed to inform on the use of NMES for people with PFP. However, professional and stakeholder consensus is required on prioritisation of the research questions for interventions for treating people with PFP, including on the NMES treatment protocol for trials testing NMES.

Coronal patellar osteotomy of the external facet combined with the release of the lateral retinaculum improves the clinical outcomes of isolated lateral release in lateral knee compartment syndrome

OBJECTIVE

To describe a novel coronal osteotomy of the external facet of the patella, and to evaluate if the outcomes of the treatment of lateral knee compartment syndrome (LKCS) with this osteotomy, combined with the release of the external lateral retinaculum, are better than the isolated lateral retinacular release.

MATERIAL AND METHODS

A prospective study with a 2 year follow up that included 70 patients diagnosed with LKCS, distributed into 2 groups. The first group included 50 patients on whom the lateral retinacular release combined with osteotomy was performed, and a second group on whom an isolated retinacular release was performed. Measurements were made using the Werner functional scale before the surgery and at 3, 12, and 24 months follow-up.

RESULTS

There were significant differences in the overall functional state between the two groups after the surgery (better in the osteotomy group at all the intervals, P<.05). The improvement, which was progressive up to 12 months, was slightly less at 24 months, although the values were still better than the pre-surgical ones in both groups. Pain was the variable that showed most improvement. The patients with LKCS with degenerative signs showed a benefit in all cases.

CONCLUSION

The results demonstrate that the described patellar osteotomy technique, combined with lateral retinacular release, significantly improves the pain and the functional scale score of patients with LKCS after 2 years of follow-up, to a greater extent than isolated lateral retinacular release, including those in which there was evidence of degenerative signs.

Knee orthoses for treating patellofemoral pain syndrome

BACKGROUND

Patellofemoral pain syndrome (PFPS) is a painful musculoskeletal condition, which is characterised by knee pain located in the anterior aspect (front) and retropatellar region (behind) of the knee joint. Various non-operative interventions are suggested for the treatment of this condition. Knee orthoses (knee braces, sleeves, straps or bandages) are worn over the knee and are thought to help reduce knee pain. They can be used in isolation or in addition to other treatments such as exercise or non-steroidal anti-inflammatory medications.

OBJECTIVES

To assess the effects (benefits and harms) of knee orthoses (knee braces, sleeves, straps or bandages) for treating PFPS.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (11 May 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2015 Issue 5), MEDLINE (1946 to 8 May 2015), EMBASE (1980 to 2015 Week 18), SPORTDiscus (1985 to 11 May 2015), AMED (1985 to 8 May 2015), CINAHL (1937 to 11 May 2015), PEDro (1929 to June 2015), trial registries and conference proceedings.

SELECTION CRITERIA

Randomised and quasi-randomised controlled clinical trials evaluating knee orthoses for treating people with PFPS. Our primary outcomes were pain and function.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for eligibility, assessed study risk of bias and extracted data. We calculated mean differences (MD) or, where pooling data from different scales, standardised mean differences (SMD) with 95% confidence intervals (CI) for continuous outcomes and risk ratios (RR) with 95% CIs for binary outcomes. We pooled data using the fixed-effect model.

MAIN RESULTS

We included five trials (one of which was quasi-randomised) that reported results for 368 people who had PFPS. Participants were recruited from health clinics in three trials and were military recruits undergoing training in the other two trials. Although no trials recruited participants who were categorised as elite or professional athletes, military training does comprise intensive exercise regimens. All five trials were at high risk of bias, including performance bias reflecting the logistical problems in these trials of blinding of participants and care providers. As assessed using the GRADE approach, the available evidence for all reported outcomes is 'very low' quality. This means that we are very uncertain about the results.The trials covered three different types of comparison: knee orthosis and exercises versus exercises alone; one type of orthosis versus another; and knee orthosis versus exercises. No trials assessed the mode of knee orthosis use, such as whether the orthosis was worn all day or only during physical activity. Two trials had two groups; two trials had three groups; and one trial had four groups.All five trials compared a knee orthosis (knee sleeve, knee brace, or patellar strap) versus a 'no treatment' control group, with all participants receiving exercises, either through a military training programme or a home-based exercise programme. There is very low quality evidence of no clinically important differences between the two groups in short-term (2 to 12 weeks follow-up) knee pain based on the visual analogue scale (0 to 10 points; higher scores mean worse pain): MD -0.46 favouring knee orthoses, 95% CI -1.16 to 0.24; P = 0.19; 234 participants, 3 trials). A similar lack of clinically important difference was found for knee function (183 participants, 2 trials). None of the trials reported on quality of life measures, resource use or participant satisfaction. Although two trials reported on the impact on sporting or occupational participation, one trial (35 participants) did not provide data split by treatment group on the resumption of sport activity and the other reported only on abandonment of military training due to knee pain (both cases were allocated a knee orthosis). One trial (59 participants, 84 affected knees) recording only adverse events in the two knee orthoses (both were knee sleeves) groups, reported 16 knees (36% of 44 knees) had discomfort or skin abrasion.Three trials provided very low quality evidence on single comparisons of different types of knee orthoses: a knee brace versus a knee sleeve (63 participants), a patella strap with a knee sleeve (31 participants), and a knee sleeve with a patellar ring versus a knee sleeve only (44 knees). None of three trials found an important difference between the two types of knee orthosis in pain. One trial found no clinically important difference in function between a knee brace and a knee sleeve. None of the three trials reported on quality of life, resource use or participant satisfaction. One trial comparing a patella strap with a knee sleeve reported that both participants quitting military training due to knee pain were allocated a knee sleeve. One poorly reported trial found three times as many knees with adverse effects (discomfort or skin abrasion) in those given knee sleeves with a patella ring than those given knee sleeves only.One trial compared a knee orthosis (knee brace) with exercise (66 participants). It found very low quality evidence of no clinically important difference between the two intervention groups in pain or knee function. The trial did not report on quality of life, impact on sporting or occupational participation, resource use, participant satisfaction or complications.

AUTHORS' CONCLUSIONS

Overall, this review has found a lack of evidence to inform on the use of knee orthoses for treating PFPS. There is, however, very low quality evidence from clinically heterogeneous trials using different types of knee orthoses (knee brace, sleeve and strap) that using a knee orthosis did not reduce knee pain or improve knee function in the short term (under three months) in adults who were also undergoing an exercise programme for treating PFPS. This points to the need for good-quality clinically-relevant research to inform on the use of commonly-available knee orthoses for treating PFPS.

The Role of Botulinum Toxin Type A in the Clinical Management of Refractory Anterior Knee Pain

Anterior knee pain is a highly prevalent condition affecting largely young to middle aged adults. Symptoms can recur in more than two thirds of cases, often resulting in activity limitation and reduced participation in employment and recreational pursuits. Persistent anterior knee pain is difficult to treat and many individuals eventually consider a surgical intervention. Evidence for long term benefit of most conservative treatments or surgical approaches is currently lacking. Injection of Botulinum toxin type A to the distal region of vastus lateralis muscle causes a short term functional “denervation” which moderates the influence of vastus lateralis muscle on the knee extensor mechanism and increases the relative contribution of the vastus medialis muscle. Initial data suggest that, compared with other interventions for anterior knee pain, Botulinum toxin type A injection, in combination with an active exercise programme, can lead to sustained relief of symptoms, reduced health care utilisation and increased activity participation. The procedure is less invasive than surgical intervention, relatively easy to perform, and is time- and cost-effective. Further studies, including larger randomized placebo-controlled trials, are required to confirm the effectiveness of Botulinum toxin type A injection for anterior knee pain and to elaborate the possible mechanisms underpinning pain and symptom relief.

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.

Anterior knee pain: an update of physical therapy

Anterior knee pain is one of the most common knee problems in physically active individuals. The reason for anterior knee pain has been suggested to be multifactorial with patella abnormalities or extensor mechanism disorder leading to patellar malalignment during flexion and extension of the knee joint. Some patients complain mostly of non-specific knee pain, while others report patellar instability problems. The patients present with a variety of symptoms and clinical findings, meaning that a thorough clinical examination is the key for optimal treatment. Weakness of the quadriceps muscle, especially during eccentric contractions, is usually present in the majority of anterior knee pain patients. However, irrespective of whether pain or instability is the major problem, hypotrophy and reduced activity of the vastus medialis are often found, which result in an imbalance between vastus medialis and vastus lateralis. This imbalance needs to be corrected before quadriceps exercises are started. The non-operative rehabilitation protocol should be divided into different phases based on the patient's progress. The goal of the first phase is to reduce pain and swelling, improve the balance between vastus medialis and vastus lateralis, restore normal gait, and decrease loading of the patello-femoral joint. The second phase should include improvement of postural control and coordination of the lower extremity, increase of quadriceps strength and when needed hip muscle strength, and restore good knee function. The patient should be encouraged to return to or to start with a suitable regular physical exercise. Therefore, the third phase should include functional exercises. Towards the end of the treatment, single-leg functional tests and functional knee scores should be used for evaluating clinical outcome. A non-operative treatment of patients with anterior knee pain should be tried for at least 3 months before considering other treatment options.

Rehabilitation of the patellofemoral joint

Nonsurgical care by a specialist in physical medicine and rehabilitation is typically a multifaceted approach, which can include modalities, bracing, medication, injection, proprioceptive techniques, restoration of normal movement patterns, and overall conditioning. There is evidence that physical therapy interventions have significant beneficial effect on pain and function compared with no treatment.

Increased risk of osteoarthritis after anterior cruciate ligament reconstruction: a 14-year follow-up study of a randomized controlled trial

BACKGROUND

The reported prevalence of radiological osteoarthritis (OA) after anterior cruciate ligament (ACL) reconstruction varies from 10% to 90%. Purpose/

HYPOTHESIS

To report the prevalence of OA after ACL reconstruction and to compare the OA prevalence between quadrupled semitendinosus tendon (ST) and bone-patellar tendon-bone (BPTB) grafts. The hypothesis was that there would be no difference in OA prevalence between the graft types. The secondary aim was to study whether patient characteristics and additional injuries were associated with long-term outcomes.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Radiological examination results, Tegner activity levels, and Knee injury and Osteoarthritis Outcome Score (KOOS) values were determined in 135 (82%) of 164 patients at a mean of 14 years after ACL reconstruction randomized to an ST or a BPTB graft. Osteoarthritis was defined according to a consensus by at least 2 of 3 radiologists of Kellgren-Lawrence grade ≥2. Using regression analysis, graft type, sex, age, overweight, time between injury and reconstruction, additional meniscus injury, and a number of other variables were assessed as risk factors for OA 14 years after ACL reconstruction.

RESULTS

Osteoarthritis of the medial compartment was most frequent, with 57% of OA cases in the ACL-reconstructed knee and 18% of OA cases in the contralateral knee (P < .001). There was no difference between the graft types: 49% of OA of the medial compartment for BPTB grafts and 65% for ST grafts (P = .073). The KOOS results were lower for patients with OA in all subscales, indicating that OA was symptomatic. No difference in the KOOS between the graft types was found. Meniscus resection was a strong risk factor for OA of the medial compartment (odds ratio, 3.6; 95% CI, 1.4-9.3) in the multivariable logistic regression analysis.

CONCLUSION

A 3-fold increased prevalence of OA was found after an ACL injury treated with reconstruction compared with the contralateral healthy knee. No differences in the prevalence of OA between the BPTB and quadrupled ST reconstructions were found. An initial meniscus resection was a strong risk factor for OA; the time between injury and reconstruction was not.

Donor-site-related functional problems following anterior cruciate ligament reconstruction: development of a self-administered questionnaire

PURPOSE

To develop a self-administered questionnaire for the evaluation of donor-site-related functional problems after anterior cruciate ligament (ACL) reconstruction with autograft harvested from the hamstring tendon or patellar tendon and to determine the content validity, reliability and preliminary factor structure of this new instrument.

METHODS

Seven physiotherapists with long clinical experience of rehabilitation after ACL reconstruction and 60 patients from the target population participated as experts in the developmental stages of the questionnaire. Content validity was determined and quantified with the content validity index (CVI). Test-retest reliability, internal consistency and factor structure were evaluated in another 64 patients reconstructed with an autograft.

RESULTS

The final questionnaire included 16 items on symptoms and function during activities of daily living and exercise. Excellent content validity on both item level (I-CVI ≥ 0.83, range 0.83-1.00) and scale level (S-CVI = 0.93) was found. The test-retest reliability was good, ICC = 0.94. Internal consistency was high, and Cronbach's α was 0.92 and 0.94 at each test occasion. The principal components analysis yielded a four-component structure.

CONCLUSIONS

The questionnaire "Donor-site-Related Functional Problems following Anterior Cruciate Ligament (ACL) Reconstruction" is a patient-reported questionnaire with high content validity and reliability for the evaluation of donor-site-related functional problems after ACL reconstruction, with autograft harvested from the hamstring tendon or patellar tendon. The results of this study support the use of this questionnaire as a standardized outcome measure for both research purposes and in clinical settings.

Quality of life and clinical outcome after anterior cruciate ligament reconstruction using patellar tendon graft or quadrupled semitendinosus graft: an 8-year follow-up of a randomized controlled trial

BACKGROUND

Randomized controlled trials after anterior cruciate ligament reconstructions with long-term follow-up including assessment of health-related quality of life are rare.

PURPOSE

To compare clinical outcome and health-related quality of life 8 years after anterior cruciate ligament reconstruction using 2 types of graft.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Long-term follow-up of 164 patients with anterior cruciate ligament injury randomized to arthroscopic reconstruction with a quadrupled semitendinosus graft or a bone-patellar tendon-bone graft was undertaken. After a mean 8 years, 153 patients were available for follow-up, including instrumented laxity, 1-legged hop test, a knee-walking test, and assessment with International Knee Documentation Committee, Lysholm, Tegner, and patellofemoral pain score. Health-related quality of life was assessed with Knee Osteoarthritis Outcome Score and Short Form-36.

RESULTS

Patients in both graft groups retained the same stability, knee function, and health-related quality of life. The patellofemoral pain score was similar for both groups; the bone-patellar tendon-bone group had more donor site morbidity from kneeling and knee walking. In the bone-patellar tendon-bone group, 19 patients had no kneeling problems, 23 slight problems, 31 moderate problems, and 5 unable to kneel. Corresponding figures for the semitendinosus group were 25, 32, 16, and 2 (P < .001). Patients with early reconstructions (<5 months) had a lower risk for meniscal injuries (37%) than did later reconstructed (62%, P = .008). Health-related quality of life regarding physical functioning in Short Form-36 was better for the early-reconstructed patients than for the later reconstructed (92 vs 85; P = .014). Patients without medial meniscal surgery had higher Knee Osteoarthritis Outcome Scores for all subscales than did patients with medial meniscal surgery, with most significant difference for sport and recreation (63 vs 75, P = .008).

CONCLUSION

In the long term, the semitendinosus graft provided similar stability, knee function, and health-related quality of life but with less kneeling morbidity than did the bone-patellar tendon-bone graft.

[Biomechanical issues in patellofemoral joint rehabilitation]

Specific knowledge of the biomechanics of the patellofemoral joint is crucial for successful nonoperative or postsurgical rehabilitation. The biomechanical aspects of different situations should be considered when designing an exercise program. Joint reaction forces, contact area, and contact stress are dependent on flexion angle and exercise situations. In weight-bearing activities, the amount of knee flexion directly influences the magnitude of quadriceps muscle force, which affects the magnitude of patellofemoral joint reaction forces. Open and closed chain exercises should be performed within a safe range of motion to allow quadriceps activation while minimizing patellofemoral joint reaction forces. The isolated knee extension (90 degrees -40 degrees ), the squat (0 degrees -30 degrees -60 degrees ), and the leg press (0 degrees -30 degrees -60 degrees ) are the three main exercise situations in the acute rehabilitation phase. Controlled body positions and low levels of pain and symptoms should also be emphasized to achieve a functional progression, focusing on neuromuscular control.

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.

The severity and prediction of anterior knee pain post tibial nail insertion

OBJECTIVES

To compare the prevalence of anterior knee pain and functional impairment post-tibial nailing to the contralateral knee and a background population.

DESIGN

Patients were assessed by postal questionnaire, case note, and radiographic review. An age demographically matched control group answered the same questions.

SETTING

The Orthopaedic Department at our institution.

PATIENTS/PARTICIPANTS

Patients who had a tibial nail inserted between September 1999 and November 2004 in our hospital (85 patients). Twelve were excluded, and 52 replies from 73 cases (71%) were received. The mean age was 39.4 years (range 22-69), and 38 of the patients were men.

INTERVENTION

Patients treated with AO tibial nail.

MAIN OUTCOME MEASUREMENTS

Both knees were assessed using an analogue pain score (0-10) and a functional anterior knee pain score (0-50).

RESULTS

Of the patients, 83% had anterior knee pain following tibial nailing. The mean analogue pain score was 4.3, and the functional score was 33.3. The prevalence of anterior knee pain in the uninjured knee was 40%; in the control group it was 42%. Mean visual analogue scores were 1.3 and 1.2, respectively (both P<0.001 compared to the nailed side). Functional knee pain scores were 43.3 and 46.8 (both P<0.001 compared to the nailed side). Pain scores between both the knee on the injured and the contralateral sides correlated significantly (P<0.01). Last, the pain scores of the patients' knees of the uninjured side in the operative group and the scores from the control group appeared similar but not with statistical significance (P<0.57 analogue pain score and P<0.77 functional knee pain score).

CONCLUSIONS

There is a significant preinjury prevalence of anterior knee pain. Postnailing knee pain severity correlates with that in the uninjured limb. Relative risk of anterior knee pain postnailing is twice that of a comparative population.

Early versus late start of open kinetic chain quadriceps exercises after ACL reconstruction with patellar tendon or hamstring grafts: a prospective randomized outcome study

The purpose of the present investigation was to evaluate physical outcome after anterior cruciate ligament (ACL) reconstruction with early versus late initiation of open kinetic chain (OKC) exercises for the quadriceps in patients operated on either patellar tendon or hamstring grafts. Sixty-eight patients, 36 males and 32 females, with either patellar tendon graft (34 patients) or hamstring graft (34 patients) were enrolled in this study. All patients were randomly allocated to either early (the 4th postoperative week) or late (the 12th postoperative week) start of OKC exercises for the quadriceps, resulting in four subgroups: patellar tendon reconstruction, early start (P4) or late start (P12) of OKC quadriceps exercises, hamstring tendon reconstruction, early start (H4) or late start (H12) of quadriceps OKC exercises. Prior to surgery and 3, 5 and 7 months later, assessments of range of motion (goniometer), anterior knee laxity (KT-1000), postural sway (KAT 2000), thigh muscle torques (Kin-Com dynamometer) and anterior knee pain (anterior knee pain score) were evaluated. No significant group differences were found in terms of range of motion 3, 5 and 7 months postoperatively. The H4 group showed a significantly higher mean difference of laxity over time of 1.0 mm (CI: 0.18-1.86) than the P4 group (P=0.04). Within the same type of surgery, the H4 against the H12, the mean difference over time was 1.2 mm (0.37-2.1) higher in the H4 group than in the H12 group (P=0.01). There were no significant group differences in terms of postural sway or anterior knee pain at the different test occasions. Significant differences in trends (changes over time) were found when comparing the four groups, for both quadriceps muscle torques (P<0.001) and hamstring muscle torques (P<0.001). All groups, except the P4 group, reached preoperative values of quadriceps muscle torques at the 7 months follow-up. In the H4 and the H12 groups, significantly lower hamstring muscle torques at the 7 months follow-up compared with preoperative values were found. In conclusion, early start of OKC quadriceps exercises after hamstring ACL reconstruction resulted in significantly increased anterior knee laxity in comparison with both late start and with early and late start after bone-patellar tendon-bone ACL reconstruction. Furthermore, the early introduction of OKC exercises for quadriceps did not influence quadriceps muscle torques neither in patients operated on patellar tendon nor hamstring tendon grafts. On the contrary, it appears as if the choice of graft affected the strength of the specific muscle more than the type of exercises performed. Our results could not determine the appropriate time for starting OKC quadriceps exercises for patients who have undergone ACL reconstruction with hamstring tendon graft. Future studies of long-term results of anterior knee laxity and functional outcome are needed.

Effectiveness of patellar bracing for treatment of patellofemoral pain syndrome

OBJECTIVE

To determine the effectiveness of patellar bracing for treatment of patellofemoral pain syndrome (PFPS).

DESIGN

Prospective, randomized, single-blinded clinical trial.

SETTING

Subjects recruited from the general population of the city of Calgary.

SUBJECTS

A total of 136 subjects (79 females and 57 males with a total of 197 affected knees) diagnosed with PFPS.

INTERVENTION

Subjects were randomly assigned to 1 of 4 treatment groups: (1) home exercise program, (2) patellar bracing, (3) home exercise program with patellar bracing, and (4) home exercise program with knee sleeve.

OUTCOME MEASURES

The outcome measurements were knee function (KF) and 10-cm visual analogue scale (VAS) pain ratings for 3 different situations: knee pain during sport activity, knee pain 1 hour after sport activity, and knee pain after sitting with knees bent for 30 minutes. The outcome measurements were assessed at baseline and at 3, 6, and 12 weeks. The investigators were blinded to the treatment group of each subject. Calculations were made for 95% confidence intervals for the change in KF and VAS pain ratings from baseline measurement to 12 weeks.

RESULTS

There was no difference in the 95% confidence intervals in the change of KF and VAS pain ratings among the 4 treatment groups over 12 weeks.

CONCLUSIONS

Symptoms of PFPS improved over time in terms of pain and knee function regardless of the treatment group. Patellar bracing did not improve the symptoms of PFPS more quickly when added to a home program of leg strengthening. However, patellar bracing alone can improve the symptoms of PFPS.

Clinical classification of patellofemoral pain syndrome: guidelines for non-operative treatment

The patellofemoral pain syndrome (PFPS) remains a challenging musculoskeletal entity encountered by clinicians. Reviewing the literature, conflicting data seem to exist regarding the effect of non-operative treatment in PFPS patients. A possible explanation may be lack of a clear classification system of patients with PFPS. It is our opinion that the term PFPS still is a 'wastebasket', which probably comprises several different entities. Therefore, it seems important to subdivide this broad group of patients into different categories with a specific rehabilitation approach. In this study, we introduce a classification system, which reflects a consensus reached by the European Rehabilitation Panel. This classification system should help the clinicians to identify the cause(s) of patellofemoral pain, and consequently help to select the most appropriate non-operative treatment. The authors are aware that no rehabilitation protocol will work for all PFPS patients, since the underlying mosaic of pathophysiology and tissue-healing responses are unique. Therefore, the aim of this study with a classification system was to guide the clinician through clinical examination in order to develop a non-operative treatment protocol, specific for each individual with PFPS.

Anterior cruciate ligament reconstruction: bone-patellar tendon-bone compared with double semitendinosus and gracilis tendon grafts. A prospective, randomized clinical trial

BACKGROUND

The choice of graft for anterior cruciate ligament reconstruction is a matter of debate, with patellar and hamstring tendons being the two most popular autologous graft options. The objective of this study was to determine in a prospective, randomized clinical trial whether two grafts (bone-patellar tendon-bone or doubled hamstring tendons) fixed with modern devices affect the two-year minimum clinical and radiographic outcomes of anterior cruciate ligament reconstruction.

METHODS

One hundred and twenty patients with a chronic unilateral rupture of the anterior cruciate ligament underwent arthroscopically assisted reconstruction with use of either autologous bone-patellar tendon-bone or doubled hamstring tendon grafts, in a strictly alternating manner. Both groups were comparable with regard to demographic data, preoperative activity level, mechanism of injury, interval between the injury and the operation, and the amount of knee laxity present preoperatively. The same well-proven surgical technique and aggressive controlled rehabilitation was used. An independent observer, who was blinded with regard to the involved leg and the type of graft, performed the outcome assessment with use of a visual analog scale, the new International Knee Documentation Committee form, the Knee Injury and Osteoarthritis Outcome Score, the Functional Knee Score for Anterior Knee Pain, and an arthrometric and an isokinetic dynamometric evaluation. Radiographs were also made.

RESULTS

At the two-year follow-up evaluation, no differences were found in terms of the visual analog score, the Knee Injury and Osteoarthritis Outcome Score, the new International Knee Documentation Committee subjective and objective evaluation scores, the KT-1000 side-to-side laxity measurements, the Functional Knee Score for Anterior Knee Pain, muscle strength recovery, or return to sports activities. In the bone-patellar tendon-bone group, we found a higher prevalence of postoperative kneeling discomfort (p < 0.01) and an increased area of decreased skin sensitivity (p < 0.001). In the hamstring tendon group, we recorded a higher prevalence of femoral tunnel widening (p < 0.01). In this group, a correlation was also found between medial meniscectomy and an increased prevalence of pivot-shift glide (p = 0.035).

CONCLUSIONS

We believe that, with use of accurate and proven surgical and rehabilitation techniques, both grafts are an equivalent option for anterior cruciate ligament reconstruction.

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.

Quadrupled bone-semitendinosus anterior cruciate ligament reconstruction: a clinical investigation in a group of athletes

PURPOSE

The hypothesis of our study was that a quadrupled bone-semitendinosus (STB) graft could provide a clinically stable construct, allow recovery of normal limb strength, give high patient satisfaction with early return to active sports, and involve low donor-site morbidity.

TYPE OF STUDY

Outcomes study.

METHODS

Anterior cruciate ligament (ACL) reconstruction with an STB graft was performed on 80 athletes with isolated ACL injury from January 1996 to December 1999. Femoral fixation was obtained with EndoButton (Smith & Nephew, Andover, MA) and tibial fixation with Fastlok (Neoligaments, Leeds, England). At a mean follow-up time of 36 months (range, 24-52 months), patients were evaluated using standard knee scores (Noyes, Lysholm, Tegner, and International Knee Documentation Committee [IKDC] rating) and functional strength tests; postoperative pain rating; knee radiographs performed after surgery and at final follow-up; magnetic resonance imaging (MRI) at 3 to 6 months; isokinetic flexion-extension and internal-external rotation tests at 3, 6, and 12 months; and computed laxity analysis at final evaluation.

RESULTS

At final evaluation, subjective knee rating was 87%, kneeling test was positive in 7%, and Werner score was 44 of 50 (range, 30-48). Lachman test was negative in 90% at final evaluation. Sensory changes were present in 30% at 3 months, and 10% had definite hyposthesia. Computed laxity analysis revealed 90% with less than 3 mm side-to-side difference. Isokinetic testing showed normal hamstring and quadriceps peak torques at 12 months. The one-leg hop test and vertical jump were normal by 6 months. At final evaluation, average Noyes score was 88 (range, 65-100); Lysholm score, 91 (range, 70-100); postoperative Tegner rating, 6.5 (range, 5-9); and preinjury Tegner rating, 7.5 (range, 7-10). IKDC score showed 72 knees normal or nearly normal, 7 abnormal, and 1 severely abnormal. Sixty-five percent of patients returned to the same preinjury sports level.

CONCLUSIONS

The quadrupled bone-semitendinosus graft is a viable graft for ACL reconstruction and should be considered, especially for patients with extensor mechanism problems.

The effect of exercise regimens on reflex response time of the vasti muscles in patients with anterior knee pain: a prospective randomized intervention study

The purpose of this prospective randomized intervention study was to evaluate the effect of two exercise protocols on reflex response time of vastus medialis obliquus (VMO), vastus lateralis (VL), in patients with anterior knee pain. Sixty patients were randomized into a 5-week treatment program, which consisted of only open kinetic chain tonification exercises (group I) (n = 30), or only closed kinetic chain tonification exercises (group II) (n = 30). Assessment of an aspect of neuromotor control was obtained by measuring the reflex response times of VMO and VL at the time of initial clinical examination, at the end of the exercise period (five weeks), and three months after the completion of the exercise period. At these evaluation occasions, the intensity and the number of times that the patients experienced anterior knee pain during daily life was recorded on a Visual Analog Scale (VAS). No alterations in reflex response times of VMO and VL were observed in either group. Changes of anterior knee pain over time were statistically significant in both groups. Only small and not statistically supported differences in anterior knee pain were found between the two groups. These results suggest that the reflex response times of the two vasti muscles can not be altered after a five week open or closed kinetic chain exercise program. In contrast, knee pain decreased significantly in both groups.

Vastus medialis electrical stimulation to improve lower extremity function following a lateral patellar retinacular release

STUDY DESIGN

A single-case study design.

OBJECTIVES

To examine the effect of electrical stimulation of the vastus medialis muscle on stiffness, pain and function for a patient with delayed functional progress following a lateral patellar retinacular release.

BACKGROUND

Five months after an arthroscopic lateral patellar retinacular release, the patient, although highly motivated, had made little progress using routine exercises and taping.

METHODS AND MEASURES

An electrical stimulation program producing approximately 300 contractions daily of the vastus medialis muscle was implemented. The electrical stimulation applied for 33 of the 36 days was a rectangular and balanced biphasic pulse of 625-micros duration, 70-Hz frequency, 8-second peak on-time, 3-second off-time, 1-second ramp-up, and 0.5-second ramp-down. Objective measures of stair climbing and hopping, together with the subjective measure of therapist-palpated superomedial patella displacement force, were recorded for each treatment visit. Other subjective measures were the patient's daily recordings of knee pain and stiffness.

RESULTS

Patient-reported stiffness reduced rapidly as the actual and cumulative number of daily contractions of the vastus medialis muscle increased. After 8 days of electrical stimulation, the patient was able to ascend stairs unassisted and after another 21 days to hop unsupported.

CONCLUSIONS

Stiffness rapidly reduced and function started to improve once the electrical stimulation program was implemented. Recovery during the 36 days of treatment with electrical stimulation was greater than during the previous 5 months using other methods. Compliance was not an issue, nor was muscle soreness.

Which factors predict outcome in the treatment program of anterior knee pain?

The goal of this prospective study was to determine the outcome-predictive role of various parameters in the nonoperative treatment of chronic anterior knee pain patients. Thirty patients followed a five-week treatment program, which consisted out of only closed kinetic chain exercises. Prior to this treatment all subjects were evaluated on muscular characteristics, subjective symptoms, weight, sex, duration of symptoms and functional performance. A multiple stepwise regression analysis revealed that the reflex response time of m. vastus medialis obliquus (VMO) (P=0.041; 0.026), and the duration of symptoms (P=0.019; 0.045) were the only two parameters which were significantly associated with the outcome (evaluated by the Kujala score) at five weeks, and at three months. The shorter the duration of symptoms, or the faster the reflex response time of VMO prior to the treatment, the better the outcome after a closed kinetic chain exercise program. The statistical significance of these parameters in this study may be seen as an indication of the importance of these variables as predictors of the outcome of a closed kinetic chain strengthening program. Using this information, it seems clinically important to begin the treatment program before the anterior knee pain becomes more chronic and treatment results become less good.

A comparison of two types of electrical stimulation of the quadriceps in the treatment of patellofemoral pain syndrome. A pilot study

OBJECTIVE

To compare a commercially available electrical muscle stimulation regime with a new form of stimulation for the rehabilitation of the quadriceps in patients with patellofemoral pain syndrome.

SETTING

A research facility within a teaching hospital.

METHODS

Sixteen patients (four men, 12 women) with patellofemoral pain, demonstrable quadriceps atrophy, but normal gait parameters were randomly allocated to one of two treatment groups. One group received a sequential mixed frequency stimulation pattern from a standard device. The other group received a new form of stimulation from an experimental stimulation device that contained simultaneous mixed frequency components.

OUTCOME MEASURES

Isometric and isokinetic extension torque, muscle fatigue rate, pain, functional questionnaire, step test, knee flexion, and quadriceps cross-sectional area.

RESULTS

These showed significant improvements for both groups after treatment (p < 0.05) in all outcome measures except flexion and fatigue rates, but no significant differences between the two stimulation regimes (p > 0.05).

CONCLUSION

Both stimulators performed similarly on patients with patellofemoral pain giving significant improvements for all patients for muscle strength, pain, self-reporting function and step testing. There were no significant differences between the two types of stimulation.

Failure of voluntary activation of the quadriceps femoris muscle after patellar contusion

STUDY DESIGN

Descriptive study of phenomenon.

OBJECTIVES

To determine the extent of failure of voluntary activation of the quadriceps femoris muscle in patients early after patellar contusion.

BACKGROUND

Pain and effusion are related to the presence of quadriceps inhibition. We hypothesized that patients with patellar contusions would be unable to fully recruit their quadriceps muscles and that the activation deficit would be associated with self-report measures of function.

METHODS AND MEASURES

Sixteen patients who had sustained a unilateral patellar contusion fewer than 4 months prior to testing participated in the study (7 men, 9 women; mean age = 30.0 +/- 11.6). Subjects completed a self-report questionnaire to assess knee function and performed an isometric burst superimposition test on the involved and uninvolved quadriceps at 60 degrees of knee flexion. The subjects were assigned to 2 groups according to the presence (n = 5) or absence (n = 11) of quadriceps inhibition.

RESULTS

Sixty-nine percent of the subjects tested were able to fully activate their quadriceps. Both groups had a decreased knee extensor force on the involved side compared to the uninvolved, but the group with inhibition had a lower side-to-side percentage of knee extensor force (mean = 65.5% +/- 18.9) than those without inhibition (mean = 85.5% +/- 16.4).

CONCLUSION

Early after patellar contusion, approximately one-third of the patients demonstrated quadriceps inhibition. According to our working hypothesis, the majority of the patients tested should have demonstrated inhibition. Quadriceps inhibition was not associated with the activities of daily living, sports activity, or global rating scales in this study. Decreased volitional quadriceps force production (the hallmark of inhibition) was the only variable that discriminated patients with patellar contusion who had inhibition from those who did not.

The influence of orthotic devices and vastus medialis strength and timing on patellofemoral loads during running

OBJECTIVE

To use a musculoskeletal model and simulation of running to examine: (1) the influence of two commonly prescribed treatments for patellofemoral pain (vastus medialis oblique strengthening and orthoses) and (2) the functional significance of timing differences between vastus medialis oblique and vastus lateralis on lateral patellofemoral joint loads.

DESIGN

A three-dimensional musculoskeletal model of the lower extremity was used to simulate running at 4 m/s.

BACKGROUND

Repetitive and excessive joint loading is often associated with overuse injuries that require clinical treatments to reduce pain and restore function. Affecting one in four runners, patellofemoral pain is one of the most common injuries in running. Although conservative treatments have been reported to successfully treat patellofemoral pain, the effectiveness is often based on subjective or empirical data, which have generated disagreement on the most effective treatment.

METHODS

Nine subject specific running simulations were generated and experiments were performed by applying the treatments and timing differences to the nominal simulations.

RESULTS

Both treatments significantly reduced the average patellofemoral joint load and the vastus medialis strengthening also significantly reduced the peak patellofemoral joint load. In addition, when the vastus medialis oblique timing was delayed and advanced relative to the vastus lateralis timing, a significant increase and decrease in the joint load was observed, respectively, during the loading response.Conclusions. Increasing vastus medialis oblique strength yielded more consistent results across subjects than the orthosis in reducing patellofemoral joint loads during running. The effect of orthoses was highly variable and sensitive to the individual subject's running mechanics. Vastus medialis oblique activation timing is an important determinant of lateral patellofemoral joint loading during the impact phase.

RELEVANCE

These findings indicate that a reduction in patellofemoral pain may be achieved through techniques that selectively increase the vastus medialis oblique strength. Therefore, future studies should be directed towards identifying such techniques. Additionally, the functional significance of timing differences between the vastus medialis oblique and vastus lateralis is an important consideration in patellofemoral pain treatment and orthoses may be beneficial for some patients depending on their running mechanics.

Rehabilitation complications following knee surgery

When pain and effusion have been minimized and patients assume appropriate knee posture at rest and during exercise, the extent of postinjury or postoperative quadriceps femoris neuromuscular inhibition and avoidance during locomotion is reduced. Restoring normal lower-extremity ROM and musculotendinous extensibility (with consideration for biarticular muscles) is foundational to the implementation of an exercise program that integrates the trunk, hip, and ankle muscles into dynamic knee-stabilization challenges while addressing isolated quadriceps femoris deficiencies. Cardiovascular conditioning should be addressed as early as feasible. Although programs generally address anaerobic and aerobic energy systems, increasing patients' fatigue resistance, as evidenced by prolonged maintenance of appropriate functional exercise techniques and body control without verbalized discomfort or observed movement-avoidance patterns, ensures therapists that neuromuscular responsiveness for dynamic knee stabilization is improving.

Isokinetic quadriceps training in patients with patellofemoral pain syndrome

The aims of the present investigation were (a) to evaluate the effect of eccentric quadriceps training in patients with unilateral patellofemoral pain and (b) to compare the effect of eccentric and concentric quadriceps training in patients with bilateral patellofemoral pain. Fifteen patients (9 male and 6 female, aged 17-36 years with a mean of 27.5 years) participated in this study. Nine patients had unilateral pain and trained their painful leg eccentrically, while six had bilateral pain and trained one leg eccentrically and the other concentrically. Quadriceps muscle training was performed on a Kin-Com dynamometer at 90 degrees/s and 120 degrees/s angular velocity twice a week for 8 weeks. Before and after the treatment period the thigh muscle torques were measured on the Kin-Com dynamometer at 60 degrees/s, 90 degrees/s, 120 degrees/s and 180 degrees/s for quadriceps and at 60 degrees/s and 180 degrees/s for hamstrings. Nine controls, matched for gender and age with the group with unilateral pain, were tested in the same way on the Kin-Com dynamometer. For functional evaluation a knee score was calculated before training, after 8 weeks of training and at a mean of 3.4 years after completion of the training. After 8 weeks of training and at follow-up times of 1 and 3.4 years the patients were also questioned regarding whether or not they felt improvement from the training programme. To determine the degree of knee pain during the training Borg's pain scale was used. The results showed that, compared with the controls, the patients had a significantly lower knee extensor torque in their painful leg at all velocities measured.(ABSTRACT TRUNCATED AT 250 WORDS)