The effect of a patella brace on performance in a knee extension strength test in patients with patellar pain

Clinical outcome of rim-plate-augmented separate vertical wiring with supplementary fixation for the treatment of patellar fracture associated comminuted inferior pole

Despite the variety of treatment methods, comminuted inferior pole fractures of the patella remain difficult and technically demanding to achieve stable internal fixation. The purpose of this study is to evaluate the clinical outcomes of rim plate-augmented separate vertical wiring with supplementary fixation in the management of comminuted inferior pole fractures, AO/OTA 34-A1, C2, and C3, which has the secondary horizontal fracture line on lower articular boundary. From our study, bony union was achieved in all patients at an average of 3.1 ± 1.4 months after surgery. There was no patient with loss of reduction, fixation failure, or infection during follow-up. The average final range of motion was 131.6° ± 7.2°. Lysholm knee scores gradually increased over 3, 6, 9, and 12 months postoperatively by 58.7, 74.0, 82.9, and 89.4, respectively. Isokinetic peak torque deficit of the knee extensor muscles in 3, 6, 9, and 12 months postoperatively was 59.9%, 49.7%, 35.7%, and 28.1%, respectively. The rim plate-augmented separate vertical wiring with supplementary fixation for the treatment of patellar fracture associated comminuted inferior pole is effective and can be safely applied AO/OTA 34-C2 or C3 with favorable outcomes.

Changes in Patellar Morphology Following Soft Tissue Surgical Correction of Recurrent Patellar Dislocation in Children with Low-Grade Trochlear Dysplasia

Objective

To investigate the changes in patellar morphology following soft tissue surgical correction of recurrent patellar dislocation in children with low‐grade trochlear dysplasia.

Methods

The prospective cohort study was performed between November 2007 and December 2012. Finally, 25 cases, with the mean age of 8.4 years (range from 7 to 10 years), were admitted to the study. All patients were diagnosed as bilateral recurrent patellar dislocation associated with femoral trochlear dysplasia. The knee that suffered injury or was dislocated was treated with medial patellar retinacular plasty (surgery group). The contralateral knee, which served as a control, was treated conservatively (conservative group). Axial CT scans were undertaken in all patients to assess the patellar morphological characteristics.

Results

The mean follow‐up time was 60.8 months (range 48 to 75 months). Preoperatively, there were no statistically significant differences between the patellar morphology in the two groups (P > 0.05). Many radiological parameters of patellar morphology were significantly different between the two groups at the final follow‐up, including well‐known parameters, such as the mean patellar width (surgery group, 40.58 mm [SD 1.26]; conservative group, 36.41 mm [SD 1.17]; P < 0.05), the mean patellar thickness (surgery group, 11.59 mm [SD 0.74]; conservative group, 9.38 mm [SD 0.56]; P < 0.05) and the mean Wiberg index (surgery group, 0.54 [SD 0.06]; conservative group, 0.72 [SD 0.08]; P < 0.05). There are also little‐known parameters, such as the ratio of length of lateral patella to medial patella (surgery group, 1.26 [SD 0.17]; conservative group, 1.69 [SD 0.21]; P < 0.05), which was a measurement of facet asymmetry. However, the Wiberg angle was not significantly different between the two groups (surgery group, 128.63° [SD 9.05]; conservative group, 125.47° [SD 13.96°]; P > 0.05) at the final follow‐up. No complications were found.

Conclusions

The patellar morphology can be significantly improved by early soft tissue surgical correction in children with patellar instability associated with low‐grade femoral trochlear dysplasia.

A comparative study of the acute effects of knee brace vs. kinesiotape on selected isokinetic strength variables of the knee muscles

BACKGROUND: Different methods of treatment for preventing knee injuries, enhancing knee strength and minimising post-injury risks have been explored. Among these methods, Kinesio tape (KT) and knee braces (KB) are commonly used. OBJECTIVE : To investigate the acute effects of KT and KB on isokinetic knee strength parameters. METHODS: A total of 15 healthy sedentary male subjects voluntarily participated in the study. Concentric isokinetic knee extension (EX) and flexion (FLX) strength were measured at three sessions: 1. Baseline 2. with KT (’KT’) 3. with KB (’KB’). Tests were performed at 60, 180 and 240∘/s. Peak moment (PM), Hamstring/Quadriceps ratio (HQR), and joint angle at peak moment (JAPM) were measured. RESULTS: ‘KT’ and ‘KB’ were associated with increase in PMEX, PMFLX, HQR at 60 and 240∘/s (p< 0.05) and increased JAPMEX. No significant difference was observed at 180∘/s (p> 0.05). CONCLUSION: In healthy individuals, ‘I’ shape KT and KB positively affect EX and FLX strengths and HQR, especially at low angular velocity.

Changes in patellar morphology following surgical correction of recurrent patellar dislocation in children

Background

The aim of this study was to evaluate patellar morphological changes following surgical correction of recurrent patellar dislocation in children.

Methods

A total of 35 immature children aged 5 to 10 years who suffered from bilateral recurrent patellar dislocation associated with abnormal patella morphology were enrolled in this study. The knees with the most frequent dislocations (treated with medial patellar retinacular plasty) were selected as the study group (SG), and those undergoing conservative treatment for the contralateral knee were selected as the control group (CG). Computed tomography (CT) scans were performed on all children preoperatively and at the last follow-up to evaluate morphological characteristics of the patella.

Results

All the radiological parameters of the patella showed no significant difference between the two groups preoperatively. At the last follow-up for CT scans, no significant differences were found for the relative patellar width (SG, 54.61%; CG, 52.87%; P = 0.086) and the relative patellar thickness (SG, 26.07%; CG, 25.02%; P = 0.243). The radiological parameters including Wiberg angle (SG, 136.25°; CG, 122.65°; P < 0.001), modified Wiberg index (SG, 1.23; CG, 2.65; P < 0.001), and lateral patellar facet angle (SG, 23.35°; CG, 15.26°; P < 0.001) showed statistical differences between the two groups.

Conclusions

The patellar morphology can be improved by early surgical correction in children with recurrent patellar dislocation. Therefore, early intervention is of great importance for children diagnosed with recurrent patellar dislocation.

Changes in femoral trochlear morphology following surgical correction of recurrent patellar dislocation associated with trochlear dysplasia in children

Aims

The aim of this study was to investigate the changes in femoral trochlear morphology following surgical correction of recurrent patellar dislocation associated with trochlear dysplasia in children.

Patients and Methods

A total of 23 patients with a mean age of 9.6 years (7 to 11) were included All had bilateral recurrent patellar dislocation associated with femoral trochlear dysplasia. The knee with traumatic dislocation at the time of presentation or that had dislocated most frequently was treated with medial patellar retinacular plasty (Group S). The contralateral knee served as a control and was treated conservatively (Group C). All patients were treated between October 2008 and August 2013. The mean follow-up was 48.7 months (43 to 56). Axial CT scans were undertaken in all patients to assess the trochlear morphological characteristics on a particular axial image which was established at the point with the greatest epicondylar width based on measurements preoperatively and at the final follow-up.

Results

Preoperatively, there were no statistically significant differences between the trochlear morphology in the two groups (sulcus angle, p 0.852; trochlear groove depth, p 0.885; lateral trochlear inclination, p 0.676; lateral-to-medial facet ratio, p 0.468; lateral condylar height, p 0.899; medial condylar height, p 0.816). Many radiological parameters of trochlear morphology were significantly different between the two groups at the final follow-up, including well-known parameters, such as the mean sulcus angle (Group S, 146.27° (sd 7.18); Group C, 160.61° (sd 9.29); p < 0.001), the mean trochlear groove depth (Group S, 6.25 mm (sd 0.41); Group C, 3.48 mm (sd 0.65); p < 0.001) and the mean lateral trochlear inclination (Group S, 20.99° (sd 3.87); Group C, 12.18° (sd 1.85); p < 0.001). Lesser known parameters such as the ratio of the lateral to medial trochlear length (Group S, 1.46 (sd 0.19); Group C, 2.14 (sd 0.42); p < 0.001), which is a measurement of facet asymmetry, and the lateral and medial condylar height were also significantly different between the two groups (p < 0.001).

Conclusion

The femoral trochlear morphology can be improved by early (before epiphyseal closure) surgical correction in children with recurrent patellar dislocation associated with femoral trochlear dysplasia. Cite this article: Bone Joint J 2018;100-B:811–21.

The Effect of Knee Braces on Quadriceps Strength and Inhibition in Subjects With Patellofemoral Osteoarthritis

STUDY DESIGN

Secondary analysis of a randomized controlled trial.

BACKGROUND

The use of external supports has been questioned because they may lead to weakness in the surrounding muscles. To our knowledge, there is no investigation into the effect of knee supports or braces on quadriceps muscle strength and quadriceps inhibition in individuals with patellofemoral joint (PFJ) osteoarthritis (OA).

OBJECTIVES

To investigate the effects of a flexible knee support on quadriceps maximum voluntary contraction (MVC) and arthrogenous muscle inhibition (AMI) in patients with PFJ OA.

METHODS

The study included 108 participants who had at least 3 months of patellofemoral pain and a Kellgren-Lawrence score of 2 or 3 for PFJ OA. The participants were randomized to a group that wore a flexible knee support (brace) or a group that did not wear a support (no brace) in a 6-week randomized controlled trial, followed by an open-label trial, in which all participants wore the brace for a total of 12 weeks. Quadriceps MVC, measured isometrically, and quadriceps AMI, measured by twitch interpolation, were assessed at the 6-week and 12-week time points.

RESULTS

After 6 weeks, MVC did not differ between the brace and no-brace groups (9.09 Nm; 95% confidence interval [CI]: -4.89, 23.07; P = .20). Arthrogenous muscle inhibition significantly decreased in the brace group (-8.62%; 95% CI: -13.90%, -3.33%; P = .002). After 12 weeks, in all of the participants who wore a flexible knee support, MVC increased by 7.98 Nm (95% CI: 2.52, 13.45; P = .004) and AMI decreased (-8.42%; 95% CI: -11.48%, -5.36%; P<.001). Although statistically significant, these results have doubtful clinical significance.

CONCLUSION

A patellofemoral flexible knee support in participants with PFJ OA does not have an adverse effect on quadriceps MVC or AMI. Using a knee support should not be discouraged because of concerns about deleterious effects on quadriceps strength and inhibition.

LEVEL OF EVIDENCE

Therapy, level 1b.

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.

Selective hemiepiphyseodesis for patellar instability with associated genu valgum

BACKGROUND/AIMS

Patellar instability limits activity and promotes arthritis. Correcting genu valgum with selective hemiepiphyseodesis can treat patellar instability.

METHODS

We retrospectively reviewed 26 knees with patellar instability and associated genu valgum that underwent hemiepiphyseodesis.

RESULTS

Average anatomic lateral distal femoral angle (aLDFA) significantly corrected. Symptoms improved in all patients. All competitive athletes returned to sports. One complication occurred.

CONCLUSIONS

In genu valgum, the patella seeks an abnormal mechanical axis, resulting in patellar instability. By correcting the mechanical axis with hemiepiphyseodesis, patellar instability symptoms improve and patients return to sports. Complications are rare. Selective hemiepiphyseodesis is recommended when treating patellar instability with associated genu valgum.

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.

Dynamic versus static reconstruction of the medial patellofemoral ligament for recurrent lateral patellar dislocation

PURPOSE

To compare clinical and radiological outcomes of static and dynamic medial patellofemoral ligament (MPFL) reconstruction techniques.

METHODS

In a retrospective, matched-paired, cohort analysis, 30 patients surgically treated for recurrent lateral patellar dislocation were divided into two groups of 15 patients matched for inclusion and exclusion criteria. The static technique group underwent rigid fixation of the gracilis tendon at the anatomic femoral MPFL insertion and the superomedial border of the patella; the dynamic technique group underwent detachment of the gracilis tendon at the pes anserinus with fixation to the proximal medial patellar margin via tunnel transfer obliquely through the patella. Kujala, Lysholm, and Tegner scores; pain level; and pre- and postoperative radiographic changes of patellar height, patellar tilt, and bisect offset were compared.

RESULTS

No significant between-group differences were found in mean Kujala, Tegner, Lysholm, or visual analogue scale scores or radiographic parameters. One case of resubluxation was observed in the dynamic group. All but one patient in each group would have been willing to undergo the procedure again.

CONCLUSIONS

Both techniques provided satisfactory short-term outcomes.

LEVEL OF EVIDENCE

III.

Surgical biomechanics of the patellofemoral joint

This review presents objective data, as far as possible, about the current understanding of the biomechanics of the patellofemoral joint as it pertains to the management of patellofemoral problems. When faced with a patellofemoral malfunction, it is important to check all the soft-tissue and articular geometry factors relating to the patella locally and not to neglect the overall lower limb alignment and function. It is important to remember that small alterations in alignment can result in significant alterations in patellofemoral joint stresses and that changes in the mechanics of the patellofemoral joint can also result in changes in the tibiofemoral compartments. Surgical intervention for patellofemoral problems needs to be planned carefully and take into account an individual's anatomy.

The effect of release of the popliteus and quadriceps force on rotation of the knee

The current study was done to determine whether an isolated, partial, or complete injury to the popliteus at the femur increases rotational knee laxity. The other aim was to determine how quadriceps loading affects internal and external rotation. Ten cadaver knee specimens with an intact posterolateral complex were held in a biomechanical testing rig at 0 degrees, 30 degrees, 60 degrees, and 90 degrees flexion. Movement of the tibia relative to the femur was measured while internal and external moments of 3 N-m were applied about the long axis of the tibia. Laxity was assessed for an intact specimen, and with partial and complete detachment of the popliteus femoral insertion. In five of the 10 specimens laxity additionally was assessed with sufficient quadriceps loading to resist 100 N vertical force at the hip. The results showed that partial and total release of the popliteus increased external laxity of the knee by as much as 6.6 degrees (90 degrees flexion) and by as much as 3.5 degrees (90 degrees flexion). Quadriceps loading reduced internal and external knee laxity significantly. Injury of the popliteus at the femoral insertion may be associated with increased rotational laxity of the knee. An increase in quadriceps force may be necessary to control increased external rotation of the tibia.

[Knee orthosis. First part : evaluation of physiological properties based on a review of the literature]

INTRODUCTION

The aim of this work was to proceed to a literature review to determine the physiological justifications underlying knee orthosis use in medical practice.

METHOD

An analysis of the international literature relating to the years 1980-2000 was carried out with the Medline data bank. We added extra articles focusing on the validity of the protocols used in the different evaluations.

RESULTS

Five hundred and twelve articles were selected and 46 articles of experimental validation were retained. The experimental protocols are divided into in vitro studies and clinical studies carried out in both healthy subject and patients. Only the in vitro experimental data allowed to reach strain values simulating traumatisms of the articular structures. They allowed to define the interest and limits of the orthosis according to articular physiology. Measurements carried out in vivo were effective to characterize the parameters of stability and proprioception and to discriminate between the orthosis. These studies correspond to experimental situations with related constraints that remain far below lesional constraints, focusing on their clinical validity.

CONCLUSION

This work point out many studies focusing on the physiological characterization of the knee orthosis. This evaluation of the orthosis through a single methodology remains difficult and justifies confrontation with clinical trials data.

Patellofemoral pain syndrome: a review of current issues

There is no clear consensus in the literature concerning the terminology, aetiology and treatment for pain in the anterior part of the knee. The term 'anterior knee pain' is suggested to encompass all pain-related problems. By excluding anterior knee pain due to intra-articular pathology, peripatellar tendinitis or bursitis, plica syndromes, Sinding Larsen's disease, Osgood Schlatter's disease, neuromas and other rarely occurring pathologies, it is suggested that remaining patients with a clinical presentation of anterior knee pain could be diagnosed with patello-femoral pain syndrome (PFPS). Three major contributing factors of PFPS are discussed: (i) malalignment of the lower extremity and/or the patella; (ii) muscular imbalance of the lower extremity; and (iii) overactivity. The significance of lower extremity alignment factors and pathological limits needs further investigation. It is possible that the definitions used for malalignment should be re-evaluated, as the scientific support is very weak for determining when alignment is normal and when there is malalignment. Consequently, pathological limits must be clarified, along with evaluation of risk factors for acquiring PFPS. Muscle tightness and muscular imbalance of the lower extremity muscles with decreased strength due to hypotrophy or inhibition have been suggested, but remain unclear as potential causes of PFPS. Decreased knee extensor strength is a common finding in patients with PFPS. Various patterns of weaknesses have been reported, with selective weakness in eccentric muscle strength, within the quadriceps muscle and in terminal knee extension. The significance of muscle function in a closed versus open kinetic chain has been discussed, but is far from well investigated. It is clear that further studies are necessary in order to establish the significance of various strength deficits and muscular imbalances, and to clarify whether a specific disturbance in muscular activation is a cause or an effect (or both) of PFPS. The most common symptoms in patients with PFPS are pain during and after physical activity, during bodyweight loading of the lower extremities in walking up/down stairs and squatting, and in sitting with the knees flexed. However, the source of patellofemoral pain in patients with PFPS cannot be sufficiently explained. There are several types of clinical manifestation of pain, and therefore a differentiated documentation of the patient's pain symptoms is necessary. The connection between strength, pain and inhibition, as well as between personality and pain, needs further investigation. Many different treatment protocols are described in the literature and recent studies advocate a comprehensive treatment approach allowing for an individual and specifically designed treatment. Surgical treatment is rarely indicated. It is strongly suggested that, when presenting studies on PFPS, a detailed description should be provided of the diagnosis, inclusion and exclusion criteria of the patients should be specified along with a detailed methodology, and the conclusions drawn should be compared with those of other studies in the published literature. As this is not the case in most studies on PFPS found in the literature, it is only possible to make general comparisons. In order to further develop treatment models for PFPS we advocate prospective, randomised, controlled, long term studies using validated outcome measures. However, there is a strong need for basic research on the nature and aetiology of PFPS in order to better understand this mysterious syndrome.

Effect of a patellar realignment brace on patients with patellar subluxation and dislocation. Evaluation with kinematic magnetic resonance imaging

The object of this study was to evaluate the effect of a patellar realignment brace on patients with patellar subluxation or dislocation. Twenty-one patients (24 patellofemoral joints) with clinical evidence of patellar subluxation (N = 16) or dislocation (N = 5) were examined with the joint inside a positioning device to allow active-motion, kinematic magnetic resonance imaging. To analyze the patellar tracking pattern, the same imaging parameters (patellar tilt angle, bisect offset, and lateral patellar displacement) and section locations were used before and after application of a patellar realignment brace. No statistically significant differences were found in any of the three parameters for the patellofemoral relationships before or after wearing the patellar brace. The results indicated no stabilizing effect of the tested brace in patients with patellar subluxation or dislocation during active joint motion.

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.

The role of the knee brace in the prevention of anterior knee pain syndrome

Our prospective study evaluates the use of a knee brace with a silicon patellar support ring as a method of preventing anterior knee pain from developing in young persons undergoing strenuous physical exercise. We studied 60 young athletes, who qualified for a strenuous physical training course and who had not suffered from anterior knee pain previously. Twenty-seven subjects were in the brace group and 33 were in the nonbrace control group. The incidence of anterior knee pain syndrome increased with the intensity of exertion as the study progressed; i.e., subjects ran 6 km in the 1st week, gradually increasing each week up to 42 km/week at the 8th week. Yet, there was a significant reduction in the incidence of the syndrome at the end of the study in male athletes who had applied the braces before exercise sessions and in the brace group as a whole, compared with the control group. Prophylactic use of the brace, as described, did not reduce the ability of the athletes who wore braces to improve their physical fitness parameters in response to exercise. These data indicate that the use of a brace may be an effective way to prevent the development of anterior knee pain syndromes in persons participating in strenuous and intensive physical exercise.

A biomechanical and clinical evaluation of a patellofemoral knee brace

A clinical and biomechanical evaluation of a patellofemoral knee brace was conducted to determine subjectively and objectively if the brace was effective in controlling knee motion and relieving patellofemoral pain symptoms. The subjective results indicated that the patellofemoral brace was able to significantly improve the level of perceived knee stability and decrease the level of pain experienced by all the subjects during their daily living and athletic activities. The objective results showed that the patellofemoral brace had no effect on knee flexion angle during gait or level walking, stair ascent, or stair descent for 2 groups of subjects (patellofemoral patients and controls). Joint pain and stability are affected by factors other than knee flexion angle.

Patellar taping in the treatment of patellofemoral pain. A prospective randomized study

The purpose of this prospective study was to evaluate the efficacy of a patellar taping program in the conservative management of patellofemoral pain. Twenty-five patients with patellofemoral pain were randomized into two groups. One group underwent a standard physical therapy program for patellofemoral pain. The other group underwent the same physical therapy program, but use of a patellar taping technique was added to this program. Results of a subjective visual analog scale and changes in isokinetic strength and electromyographic activity of the quadriceps muscle were analyzed. Both the tape and no-tape groups experienced a statistically significant decrease in symptoms (P < 0.05), but no difference in improvement of patellofemoral pain was noted between the groups. Likewise, both groups demonstrated significant improvement in quadriceps muscle isokinetic strength (P < 0.05) and activity (P < 0.001), but no difference in improvement was noted between groups. The results of this study suggest no beneficial effect of adding a patellar taping program to a standard physical therapy program in the conservative treatment of patellofemoral pain. Larger prospective studies are warranted to support this opinion.

Knee Bracing

The authors present an overview of the design and functional features of knee braces and their relationship to knee biomechanics. Four types of knee braces-prophylactic, rehabilitative, functional, and patellofemoral-have been developed to cover the wide variety of indications in patients who have suffered knee injuries or hope to prevent them. Important considerations when choosing specific brace types are discussed, and summaries of relevant research are presented. Clinical criteria for brace selection are offered to help physicians and sports medicine professionals in choosing the right brace for each patient.

Effect of a patellar realignment brace on patellofemoral relationships: evaluation with kinematic MR imaging

The effect of a newly developed patellar realignment brace was evaluated in 21 patellofemoral joints (19 patients) with patellar subluxation (13 joints with lateral subluxation and eight with medial subluxation) by using active-movement, loaded kinematic magnetic resonance (MR) imaging. Sixteen patellofemoral joints (76%) demonstrated a qualitative correction of or improvement in patellar subluxation (ie, centralization of the patella or a decrease in the displacement of the patella) after application of the brace. Four of the five "failures" occurred in patellofemoral joints that had patella alta and/or dysplastic bone anatomy. These results indicate that the patellar realignment brace was able to counteract patellar subluxation in the majority of patellofemoral joints studied, as shown by active-movement, loaded kinematic MR imaging. This brace appears to be useful for conservative treatment of patients with patellofemoral joint pain secondary to patellar malalignment and maltracking.

Effect of taping the patella on concentric and eccentric torque and EMG of knee extensor and flexor muscles in patients with patellofemoral pain syndrome

The acute effect of patella taping on torque and electromyographic (EMG) activity in maximal voluntary concentric and eccentric action of the knee extensor and flexor muscles in patients with patellofemoral pain syndrome was studied in 48 patients (62 knees). The patients (28 female, 20 male) were tested concentrically and eccentrically on a Kin-Com dynamometer with simultaneous EMG recording with the patella untaped and medially or laterally taped. Patients with clinically normal patellar mobility did not improve their quadriceps performance by taping of the patella; after medial taping they decreased their muscle torque during concentric work at 60 degrees/s (P < 0.05) and eccentric work at 180 degrees/s (P < 0.05). After lateral taping they decreased their muscle torque during concentric work at 60 degrees/s (P < 0.05) and eccentric work at both 60 degrees/s (P < 0.01) and 180 degrees/s (P < 0.05). Moreover, these patients also decreased their agonist EMG activity during concentric work at 60 degrees/s (P < 0.05) and 180 degrees/s (P < 0.05) and their antagonist EMG activity during eccentric work at 60 degrees/s (P < 0.01). Patients with a clinical lateral patellar hypermobility increased their knee extensor torque after medial taping at 60 degrees/s during both eccentric work (P < 0.01) and concentric work (P < 0.05). The greatest improvement in quadriceps performance, however, was in patients with a clinical medial patellar hypermobility. They increased their knee extensor torque after lateral taping during eccentric work at both 60 degrees/s (P < 0.001) and 180 degrees/s (P < 0.001) and during concentric work at 60 degrees/s (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Patellofemoral pain syndrome: a preliminary model for analysis and interpretation of isokinetic and pain parameters

This paper offers a preliminary model for analysis and interpretation of previously collected isokinetic and pain data based on a group of 55 patients who complained of patellofemoral pain syndrome. All patients underwent detailed physical examination, radiography, bone scanning, and CT. In addition the bilateral concentric and eccentric moments of the quadriceps femoris were assessed using the KinCom system. Following each individual exertion, patients rated the pain provoked according to the Borg pain scale. The clinical findings were non-specific and revealed that a large proportion of the patients had patellar malalignment but no particular pathology common to all could be demonstrated. Isokinetic analysis in combination with the subjective pain rating produced a set of parameters - quadriceps strength deficit, torque curve irregularities, and pain rank-which permitted an alternative approach to the findings. This approach can render the evaluation of certain cases of patellofemoral pain more comprehensive as well as assist in rationalizing the treatment of this heterogenous syndrome.

Clinical applicability of isokinetics: A review

The purpose of this paper is to review the recent advances made in the field of clinical isokinetics. Presentation of various methodological issues is followed by description and discussion of the role of isokinetic dynamometry in the assessment and treatment of orthopaedic disorders, mainly of the knee and trunk regions. Attention is also drawn to the possible application of isokinetics in neurological disorders. The limitations of this technique and its possible future developments conclude the review.

Brace with a lateral pad for patellar pain. 2-year follow-up of 25 patients

A patellar brace with a lateral pad was used in 25 patients with unilateral retropatellar pain syndrome. The patients were told to use the brace in activities that loaded the patella, and they were followed for 1 to 2 years. At follow-up, 8 patients were improved, while the symptoms were unchanged or worse in 17. The level of activity was increased in 4 patients, reduced in 3, and unchanged in the others. It is concluded that treatment with a patellar brace with a lateral pad is not likely to succeed in the majority of patients with retropatellar pain syndrome.

The relation between pain and torque in an isokinetic strength test of knee extension

Twenty-five patients (20 +/- 3 years) with patella tendinitis were followed over an 8-week period in order to study the relation between quadriceps muscle torque, in a Cybex test, and knee pain on exertion. Each patient was examined on three occasions; at 0, 4, and 8 weeks. During the first 5 weeks the patient was put through a treatment program with initial rest, activity modification, and local injection of betamethasone or Arteparon. Half of the patients improved, with less pain and higher torque, and the rest experienced no change. There was a significant negative correlation between pain and torque, stronger to measurements at 30 degrees than at 180 degrees/s (r = -0.59 and -0.40). The linear regression analysis, however, revealed that the same relative difference in pain was equivalent to a bigger difference in torque at 180 degrees than at 30 degrees/s.