Sonographic soft tissue arthritic changes associated with post-stroke hemiplegic knee pain: utility of musculoskeletal ultrasound in a resource-limited setting

PURPOSE: Post-stroke arthritic changes that may compromise rehabilitation have been described in the upper and lower limbs. We aimed at evaluating the soft tissue arthritic changes associated with pain in hemiplegic knees of stroke patients in our environment. MATERIAL AND METHODS: Hemiplegic and non-hemiplegic knees of 48 stroke patients as well as both knees of 26 apparently healthy controls were evaluated with a 7.5-12 MHz linear ultrasound probe. History of knee pain, and socio-demographic, laboratory, and clinical data were recorded for all study participants. Muscle tone and power as well as functional ambulatory category (FAC) were graded for the stroke patients. Data was analysed using SPSS version 20. RESULTS: Pain was reported more often in hemiplegic than non-hemiplegic knees (n = 16 vs. n = 6, p = 0.021). The frequencies of soft tissue arthritic changes found, which included reduced lateral and medial femoral cartilage thickness, suprapatellar effusion, and irregular cartilage-bone margin, were similar between hemiplegic and non-hemiplegic knees (p > 0.05). Suprapatellar effusion and reduced lateral femoral cartilage thickness were more prevalent in the hemiplegic knees compared to the healthy control knees (p < 0.05). Stroke patients with pes anserinus tendinosis had greater risk of hemiplegic knee pain (HKP) when compared to stroke patients without this lesion (OR = 10; 95% CI: 1.7-61). FAC, muscle tone, and power showed no association with HKP. CONCLUSIONS: Soft tissue arthritic changes associated with knee pain are comparable between hemiplegic and non-hemiplegic knees of stroke patients. The risk of knee pain in stroke is higher in the presence of pes anserinus tendinosis.