Evaluation and Treatment of Knee Pain: A Review.

Importance: Approximately 5% of all primary care visits in adults are related to knee pain. Osteoarthritis (OA), patellofemoral pain, and meniscal tears are among the most common causes of knee pain. Observations: Knee OA, affecting an estimated 654 million people worldwide, is the most likely diagnosis of knee pain in patients aged 45 years or older who present with activity-related knee joint pain with no or less than 30 minutes of morning stiffness (95% sensitivity; 69% specificity). Patellofemoral pain typically affects people younger than 40 years who are physically active and has a lifetime prevalence of approximately 25%. The presence of anterior knee pain during a squat is approximately 91% sensitive and 50% specific for patellofemoral pain. Meniscal tears affect an estimated 12% of the adult population and can occur following acute trauma (eg, twisting injury) in people younger than 40 years. Alternatively, a meniscal tear may be a degenerative condition present in patients with knee OA who are aged 40 years or older. The McMurray test, consisting of concurrent knee rotation (internal or external to test lateral or medial meniscus, respectively) and extension (61% sensitivity; 84% specificity), and joint line tenderness (83% sensitivity; 83% specificity) assist diagnosis of meniscal tears. Radiographic imaging of all patients with possible knee OA is not recommended. First-line management of OA comprises exercise therapy, weight loss (if overweight), education, and self-management programs to empower patients to better manage their condition. Surgical referral for knee joint replacement can be considered for patients with end-stage OA (ie, no or minimal joint space with inability to cope with pain) after using all appropriate conservative options. For patellofemoral pain, hip and knee strengthening exercises in combination with foot orthoses or patellar taping are recommended, with no indication for surgery. Conservative management (exercise therapy for 4-6 weeks) is also appropriate for most meniscal tears. For severe traumatic (eg, bucket-handle) tears, consisting of displaced meniscal tissue, surgery is likely required. For degenerative meniscal tears, exercise therapy is first-line treatment; surgery is not indicated even in the presence of mechanical symptoms (eg, locking, catching). Conclusions and Relevance: Knee OA, patellofemoral pain, and meniscal tears are common causes of knee pain, can be diagnosed clinically, and can be associated with significant disability. First-line treatment for each condition consists of conservative management, with a focus on exercise, education, and self-management.

Patellar Tracking: An Old Problem with New Insights.

Patellofemoral pain and instability are common indications for imaging that are encountered in everyday practice. The authors comprehensively review key aspects of patellofemoral instability pertinent to radiologists that can be seen before the onset of osteoarthritis, highlighting the anatomy, clinical evaluation, diagnostic imaging, and treatment. Regarding the anatomy, the medial patellofemoral ligament (MPFL) is the primary static soft-tissue restraint to lateral patellar displacement and is commonly reconstructed surgically in patients with MPFL dysfunction and patellar instability. Osteoarticular abnormalities that predispose individuals to patellar instability include patellar malalignment, trochlear dysplasia, and tibial tubercle lateralization. Clinically, patients with patellar instability may be divided into two broad groups with imaging findings that sometimes overlap: patients with a history of overt patellar instability after a traumatic event (eg, dislocation, subluxation) and patients without such a history. In terms of imaging, radiography is generally the initial examination of choice, and MRI is the most common cross-sectional examination performed preoperatively. For all imaging techniques, there has been a proliferation of published radiologic measurement methods. The authors summarize the most common validated measurements for patellar malalignment, trochlear dysplasia, and tibial tubercle lateralization. Given that static imaging is inherently limited in the evaluation of patellar motion, dynamic imaging with US, CT, or MRI may be requested by some surgeons. The primary treatment strategy for patellofemoral pain is conservative. Surgical treatment options include MPFL reconstruction with or without osseous corrections such as trochleoplasty and tibial tubercle osteotomy. Postoperative complications evaluated at imaging include patellar fracture, graft failure, graft malposition, and medial patellar subluxation. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Patellofemoral pain syndromealters joint position sense: a case-control study / A síndrome da dor patelofemoral altera a sensação de posição articular: estudo caso-controle

Introduction: The evaluation of changes in joint position sense (JPS) of the knee may be crucial for the identification of disorders that could start during the development of patellofemoral pain syndrome (PFPS). Objective: To evaluate JPS of the knee in PFPS. Methods: Twenty nine women (15 healthy and 14 with PFPS) reproduced knee flexion angles of 45° and 60° during open kinetic chain exercises and of 45° during closed kinetic chain exercises. Results: The absolute error in the active reproduction of 45° in open kinetic chain exercises was significantly higher in the experimental group. There were significant differences in absolute and relative errors between the groups for active reproduction at 45° in open and closed kinetic chain exercises. Conclusions: This study suggests that PFPS alters JPS during active reproduction of the 45° angle in both open and closed kinetic chain exercises.

Resumo Introdução: A avaliação de alterações do senso de posição articular (SPA) do joelho é crucial para a identificação de desordens que ocorrem durante o desenvolvimento da síndrome da dor patelofemoral (SDPF). Objetivo: Avaliar o SPA do joelho na SDPF. Métodos: Vinte e nove mulheres (15 saudáveis e 14 com SDPF) reproduziram os ângulos de 45° e 60° de flexão do joelho em cadeia cinética aber - ta e de 45° em cadeia cinética fechada. Resultados: O erro absoluto na reprodução ativa do ângulo de 45° em cadeia cinética aberta foi significativamente maior no grupo experimental. Foi observada diferença significante entre os grupos nos erros relativo e absoluto para a reprodução ativa do ângulo de 45° em cadeia cinética aberta e fechada. Conclusões: Este estudo sugere que a SDPF altera a SPA durante reprodução ativa do ângulo de 45°, tanto em cadeia cinética aberta quanto em fechada.

Changes in catastrophizing and kinesiophobia are predictive of changes in disability and pain after treatment in patients with anterior knee pain.

PURPOSE: The purpose of the study was to investigate if changes in psychological variables are related to the outcome in pain and disability in patients with chronic anterior knee pain. METHODS: A longitudinal observational study on 47 patients with chronic anterior knee pain was performed in a secondary healthcare setting. Pain was measured with the visual analogue scale and disability with the Lysholm scale. The psychological variables, such as anxiety, depression, pain coping strategies, catastrophizing and fear to movement beliefs, were studied by using self-administered questionnaires. RESULTS: Among the pain coping strategies, only the catastrophizing subscale showed a significant reduction. Similarly, anxiety, depression and kinesiophobia were significantly reduced after treatment. Those patients who decreased the catastrophizing, kinesiophobia, anxiety and depression showed a greater improvement in pain and disability after a purely biomedical treatment. A multiple regression analysis revealed that changes in catastrophizing predicted the amount of improvement in pain severity and that changes in both catastrophizing and anxiety predicted changes in disability after treatment. CONCLUSION: What has been found suggests that clinical improvement in pain and disability is associated with a reduction in catastrophizing and kinesiophobia. Therefore, co-interventions to reduce catastrophizing thinking and kinesiophobia may enhance the results. LEVEL OF EVIDENCE: Prospective Cohort Study, Level I for prognosis.

Clinically insignificant association between anterior knee pain and patellofemoral lesions which are found incidentally.

BACKGROUND: Patellofemoral chondral lesions are frequently identified incidentally during the arthroscopic treatment of other knee pathologies. A role has been described for arthroscopic debridement when symptoms are known to originate from pathology of the patellofemoral joint. However, it remains unclear how to manage lesions which are found incidentally whilst tackling other pathologies. The purpose of this study was to establish the strength of association between anterior knee pain and patellofemoral lesions identified incidentally in a typical arthroscopic population. METHODS: A consecutive series of patients undergoing arthroscopy for a range of standard indications formed the basis of this cross section study. We excluded those with patellofemoral conditions in order to identify patellofemoral lesions which were solely incidental. Pre-operative assessments were performed on 64 patients, where anterior knee pain was sought by three methods: an annotated photographic knee pain map (PKPM), patient indication with one finger and by palpated tenderness. A single blinded surgeon, performed standard arthroscopies and recorded patellofemoral lesions. Statistical correlations were performed to identify the association magnitude. RESULTS: Associations were identified between incidental patellofemoral lesions and tenderness palpated on the medial patella (P = 0.007, χ(2) = 0.32) and the quadriceps tendon (P = 0.029, χ(2) = 0.26), but these associations were at best fair, which could be interpreted as clinically insignificant. CONCLUSION: Incidental patellofemoral lesions are not necessarily associated with anterior knee pain, we suggest that they could be left alone. This recommendation is only applicable to patellofemoral lesions which are found incidentally whilst addressing other pathology.

[Unsatisfactory long-term prognosis of conservative treatment of patellofemoral pain syndrome]. / Utilfredsstillende langtidsresultater efter konservativ behandling af patellofemoralt smertesyndrom.

This review overviews the long-term prognosis of conservatively treated patients with patellofemoral pain syndrome (PFPS). Median values of the 16 included studies show that 29% of soldiers, 27.8% of sports active and 24,7% of the general public will become pain free after they are diagnosed with PFPS. 21.5% of sports active and 23% of the general public diagnosed with PFPS will stop participating in sports because of knee pain. There is an indication that around one third diagnosed with PFPS will become pain free and one fourth will stop participating in sports because of knee pain.

Efeito de diferentes calçados no ínicio da atividade eletromiográfica dos músculos estabilizadores da patela / Effect of different shoes at the onset electromyographic activity of patellar stabilizer muscles

Introdução: A síndrome da dor femoropatelar (SDFP) é caracterizada por uma dor difusa na região retopatelar. A SDFP tem maior prevalência em mulheres jovens e sua etiologia não é totalmente conhecida. Objetivo: O objetivo desse trabalho foi comparar a porcentagem de disparo inicial (PDI) dos músculos vasto medial oblíquo (VMO) e vasto lateral longo (VLL) de mulheres saudáveis com disfunção femoropatelar (SDFP) ao sentar e levantar de um banco, calçando sapatos de salto alto, tênis e descalças. Métodos: Vinte mulheres foram divididas em dois grupos: controle e SDFP. O início da atividade EMG dos músculos VMO e VLL foi registrada durante a realização das tarefas, executadas com diferentes calçados. Para a comparação das PDIs foi utilizado o teste Qui-quadrado com p<0,05. Resultados: Verificou-se que o uso do tênis e do salto alto proporcionaram aumento da PDI no grupo controle. No entanto, nenhuma diferença foi observada no grupo SDFP. Conclusão: Os resultados sugerem que os indivíduos com SDFP não apresentam respostas adaptativas ao uso de diferentes calçados.

Introduction: Patellofemoral pain syndrome (PPS) is characterized by diffuse pain in the retropatellar region. The PPS has a higher prevalence in young women and its aetiology is not fully understood. Objective: The aim of this study was to compare the percentage of onset (%) of the vastus medialis oblique (VMO) and vastus lateralis longus (VLL) of healthy women and with patellofemoral pain syndrome (PPS) during sitting and standing tasks, wearing hig heeled shoes, tennis shoes and barefoot. Methods: Twenty women were divided into two groups: control group and PPS. The onset of EMG activity of VMO and VLL muscles was recorded during the tasks, using different shoes. To compare the percentage of onset was used chi-square test with p <0.05. Results: It was found that the use of high-heeled and tennis shoes promote increased the PDI in the control group. However, no difference was observed in the PPS group. Conclusion: The results suggest that individuals with PPS do not present adaptive responses to the use of different shoes.