PLoS One. 2014 Mar 27;9(3):e92901.

Clinical, radiological and ultrasonographic findings related to knee pain in osteoarthritis.

Chan KK1, Sit RW2, Wu RW3, Ngai AH3.

1School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.

2Jockey Club School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong.

3The Hong Kong Institute of Musculoskeletal Medicine, Hong Kong.

Abstract

BACKGROUND: Pain is the predominant symptom of knee osteoarthritis (OA) and the main reason of disability. Ultrasound is now one of the new imaging modality in Musculoskeletal medicine and its role in assessing the pain severity in the knee osteoarthritis is evaluated in this study.

OBJECTIVES: (1) To study the correlation between ultrasonographic (US) findings and pain score and (2) whether ultrasonographic findings show a better association of pain level than conventional X-rays in patients suffering from primary knee osteoarthritis.

METHODS: In this multi-center study, 193 patients with primary knee OA were asked to score their average knee pain using the Western Ontario and McMaster Universities Arthritis (WOMAC) questionnaire;patients would then go for a radiological and an US evaluation of their painful knee. Findings from both imaging modalities will be studied with the associated pain score.

RESULTS: Ultrasound showed that knee effusion has positive correlation with pain score upon walking (r = 0.217) and stair climbing (r = 0.194). Presence of suprapatellar synovitis had higher pain score on sitting (Spearman’s Rank correlation  = 0.355). The medial(r = 0.170) and lateral meniscus protrusion (r = 0.201) were associated with pain score upon stair climbing.

CONCLUSIONS: Our study found that both imaging modalities shown some significant association with the aspect of pain; neither one is clearly better but rather complementary to each other. A trend is found in both modalities: walking pain is related to pathologies of the either the lateral or medial tibiofemoral joint(TFJ)while stair climbing pain is related to both tibiofemoral joint pathologies and also to the patellofemoral joint (PFJ) pathology. This suggested that biomechanical derangement is an important aspect in OA knee pain.

PMID: 24675807

 

Supplement:

The concept of inflammatory and mechanical pain among osteoarthritis knee patients

The main presenting symptom of knee osteoarthritis (OA) is knee pain. In a previous study by the author [1], most OA knee patients (80%) described two different types of pain, mechanical and inflammatory pain, each presenting with a different pain quality and onset pattern. The mechanical pain described by patients was pain resulting from weight-bearing and knee movements, such as knee bending and foot lifting. This pain would become more severe with increased mechanical load, such as when lifting heavy weights, or walking up stairs or a slope, and would disappear after resting. Most patients (65%) described the pain as sharp and usually precipitated by knee movement after prolonged inactivity; for example, getting up after sitting still for a long time. This sharp pain would gradually ease after a few minutes of gentle walking or by self-massaging the knee. In contrast, the onset of inflammatory pain was less predictable. It could be triggered by weather changes, prolonged walking, a minor sprain, or from misplacement of the feet during walking. Sometimes, inflammatory pain occurred as flare-ups in the form of exacerbated pain with the background of mechanical pain. It was described as a burning pain that could persist for days without treatment. The knee might become swollen and hot and the pain was sufficiently strong to impact on daily activities and sometimes even made walking difficult. Patients found resting and ice packs helpful, but most help came from taking analgesics, especially non-steroidal anti-inflammatory drugs (NSAIDs). The frequency of inflammatory pain was highly variable, from once every few months to once every few weeks. Sometimes the inflammatory pain might have a relapsing pattern, with the pain regressing gradually and relapsing again a few days later. This pattern could persist for three to four months.

The results of the present study show that walking pain of OA knee patients is related to pathologies of the either the lateral or medial tibiofemoral joint (TFJ) while stair climbing pain is related to both TFJ pathologies and also to the patellofemoral joint (PFJ) pathology.  Such findings of PFJ pathology being related to stair climbing and not to level walking further highlight the mechanical nature of pain among OA knee patients because stair climbing demands more work from the quadriceps muscle and hence more stress and strain on the patellofemoral joint than level walking.

 

References:

  • Keith K.W. Chan, Loretta W.Y. Chan. A qualitative study on patients with knee osteoarthritis to evaluate the influence of different pain patterns on patients’ quality of life and to find out patients’ interpretation and coping strategies for the disease. Rheumatology Reports 2011; 3:e3 doi:10.4081/rr.2011.e3

 

Contact:

fig chanDr. Keith KW CHAN

Room 1201, 12/F, City Landmark I,

68 Chung On Street,

Tsuen Wan,

HONG KONG

Email:  drkeithchan@gmail.com

 

Multiselect Ultimate Query Plugin by InoPlugs Web Design Vienna | Webdesign Wien and Juwelier SchönmannMultiselect Ultimate Query Plugin by InoPlugs Web Design Vienna | Webdesign Wien and Juwelier Schönmann