Rheumatolo
Rheumatol Int (1990) 9:265 270
INTERNATIONAL Clinical and Experimental Investigations
© Springer-Verlag 1990
Intraarticular corticosteroid injection into rheumatoid arthritis knees improves extensor muscles strength P. Geborek 1, B. Mfinsson 1, F.A. Wollheim a, and U. Moritz 2 1 Department of Rheumatology and 2 Department of Physical Medicine, University Hospital, S-22185 Lund, Sweden Received December 23, 1988/Accepted July 10, 1989
Summary. Eleven arthritic knee joints in seven patients with rheumatoid arthritis were studied before and after intraarticular injection of a corticosteroid preparation. Extensor muscle torque and quantitative electromyography increased on days 7 and 14 after treatment, indicating that muscle function had been inhibited by synovitis. Clinical signs of synovitis, such as pain, range of motion and knee circumference, also improved. Synovial fluid withdrawal alone improved extensor muscle torque. Joints with instability and/or radiological cartilage involvement also improved. Key words: Rheumatoid arthritis - Synovitis Knee joint - Extensor torque - Local corticosteroid - E M G - Synovial fluid volume
Introduction Intraarticular treatment of synovitis with crystalline glucocorticosteroid preparations has been used for nearly 40 years [1-4, 12, 13]. Evaluation of therapeutic response has focused on improvements of local symptoms of synovitis, such as pain, swelling, effusion, elevated temperature and range of motion, as well as the duration of the local remission [1-13]. Increased grip strength has been reported with the combined treatments of immobilization and intraarticular glucocorticoid injection of different joints in the hand [7]. However, adjacent muscle strength after intraarticular glucocorticosteroid treatment has not been systemically studied. We quantified knee extensor torque and electromyography (EMG), as well as local discomfort before and after intraarticular injection of a glucocorticosteroid preparation into knee joints of pa-
tients with rheumatoid arthritis (RA). The findings were related to radiological cartilage involvement. Also, the impact of synovial fluid removal was studied for possible influence on muscular function. Materials and methods Patients. Eleven knee joints in seven patients with R A [14] were studied. All patients complained of local pain and had signs of knee joint synovitis, manifested by swelling, heat, effusion, pain on motion, and tenderness on palpation. Median patient age was 63 years (range 40-73), median disease duration 9 years (range 2-18), and median local synovitis duration 4 weeks (range 1-12). All patients were taking a stable nonsteroidal antiinflammatory drug (NSAID), and four were also taking second-line drugs (chloroquine, sulphasalazine, podophyllotoxine). Two were taking oral corticosteroids ( < 7.5 mg prednisolone daily). Four patients were hospitalized, but no specific knee-extensor training program was instituted. Radiological cartilage involvement was assessed by an independent radiologist, who was unaware of the other measured variables. Loaded knee radiograms taken with 6 months were graded according to the Larsen-Dale index, where 0 = normal and 5 = maximaijoint destruction [15]. Technical equipment. A strain gauge (Bofors, Karlskoga, Sweden) with a linear response between 0 and 4 000 Nm was used. To calculate the torque in Nm the distance between the ankle strap and the tibia condyle plateau was measured. E M G was recorded as full-wave rectified, low-pass filtered, and timeaveraged using DISA 05A02 equipment (DISA Electronik, Skovlunde, Denmark). The time constant was 0.8 s. Recording procedure day O. Local pain at rest and on movement was registered on two different 120 mm horizontal, anchored visual analogue scales (VAS) with end points "no pain" and "very severe pain." The knee circumference, midpatellar and 1 cm cranial to the patella, presence of lateral instability in the extended position, and the maximal voluntary extension-flexion range were recorded. The patient was positioned comfortably half-sitting on the examination bench with a sand bag under the knees and the hands resting on the belly. The knee flexion was 30 °. The strain gauge was attached to the leg of the examination bench with a chain and around the ankle with a strap. Two 1 cm
266 large silver electrodes at a distance of 2 - 3 cm were fixed over both the vastus medialis and the vastns lateralis portion of the quadriceps muscle. To identify the position of the electrodes in the subsequent registrations, their positions were marked on the skin. After two to three trials, five maximal isometric knee extensions were recorded. A local anesthetic was used subcutaneously (lidocaine 5 g/l), but care was taken not to inject any into the joint cavity. A 1.4 m m teflon cannula was inserted from the anterior lateral aspect into the suprapatellar recess, and the accessible synovial fluid was withdrawn and measured. Twenty mg of triamcinolone hexacetonid (Lederspan ®, Lederle) was injected into the joint cavity before cannula removal. Five maximal isometric knee extensions were performed, and the knee was put to rest till the following day. The patient was informed to resume normal daily activities, but not to perform specific knee muscle training. To evaluate the impact of joint aspiration alone, the same procedure as on day 0 was performed on day - 7 in the first five knee joints without glucocorticosteroid administration. Knee extensor torque, EMG, pain, knee circumference, and range of movement values were registered on day + 7 and + 14. F o r E M G and torque, the mean of the three highest values at each occasion was used. Due to variations between patients for the quantified E M G values a normalization was performed. The value before cannula insertion on day 0 was assigned "100%." The other values were calculated as percentages of this reference level. For statistical comparison between E M G and torque, the same normalization procedure was also performed for the knee extensor torque values. The difference of both torque and E M G before and after joint aspiration, as well as the difference before cannula insertion on day 0 and on days 7 and 14 (A-torque and A-EMG) have been used in some calculations (see Results). Stat&tics. Spearman's rank correlation coefficient was used as well as the Wilcoxon matched rank-sum test for paired samples in a two-tailed manner.
Results
Extensor torque, EMG, and range of motion had increased at day 7, whereas pain on motion and at rest as well as both mid- and suprapatellar knee
circumferences had decreased. Knee function at day 14 in some cases showed further improvement compared with day 7, whereas in most cases it was similar or had decreased slightly (Table 1, Figs. 1 and 2). In the five knee joints also subjected to arthrocentesis alone, torque on the whole remained unchanged after I week (Fig. 1). The extensor torque increased significantly (median A-torque 8.8 Nm, range -8.2 to 30.8, P
Rheumatol Int (1990) 9:265 270
INTERNATIONAL Clinical and Experimental Investigations
© Springer-Verlag 1990
Intraarticular corticosteroid injection into rheumatoid arthritis knees improves extensor muscles strength P. Geborek 1, B. Mfinsson 1, F.A. Wollheim a, and U. Moritz 2 1 Department of Rheumatology and 2 Department of Physical Medicine, University Hospital, S-22185 Lund, Sweden Received December 23, 1988/Accepted July 10, 1989
Summary. Eleven arthritic knee joints in seven patients with rheumatoid arthritis were studied before and after intraarticular injection of a corticosteroid preparation. Extensor muscle torque and quantitative electromyography increased on days 7 and 14 after treatment, indicating that muscle function had been inhibited by synovitis. Clinical signs of synovitis, such as pain, range of motion and knee circumference, also improved. Synovial fluid withdrawal alone improved extensor muscle torque. Joints with instability and/or radiological cartilage involvement also improved. Key words: Rheumatoid arthritis - Synovitis Knee joint - Extensor torque - Local corticosteroid - E M G - Synovial fluid volume
Introduction Intraarticular treatment of synovitis with crystalline glucocorticosteroid preparations has been used for nearly 40 years [1-4, 12, 13]. Evaluation of therapeutic response has focused on improvements of local symptoms of synovitis, such as pain, swelling, effusion, elevated temperature and range of motion, as well as the duration of the local remission [1-13]. Increased grip strength has been reported with the combined treatments of immobilization and intraarticular glucocorticoid injection of different joints in the hand [7]. However, adjacent muscle strength after intraarticular glucocorticosteroid treatment has not been systemically studied. We quantified knee extensor torque and electromyography (EMG), as well as local discomfort before and after intraarticular injection of a glucocorticosteroid preparation into knee joints of pa-
tients with rheumatoid arthritis (RA). The findings were related to radiological cartilage involvement. Also, the impact of synovial fluid removal was studied for possible influence on muscular function. Materials and methods Patients. Eleven knee joints in seven patients with R A [14] were studied. All patients complained of local pain and had signs of knee joint synovitis, manifested by swelling, heat, effusion, pain on motion, and tenderness on palpation. Median patient age was 63 years (range 40-73), median disease duration 9 years (range 2-18), and median local synovitis duration 4 weeks (range 1-12). All patients were taking a stable nonsteroidal antiinflammatory drug (NSAID), and four were also taking second-line drugs (chloroquine, sulphasalazine, podophyllotoxine). Two were taking oral corticosteroids ( < 7.5 mg prednisolone daily). Four patients were hospitalized, but no specific knee-extensor training program was instituted. Radiological cartilage involvement was assessed by an independent radiologist, who was unaware of the other measured variables. Loaded knee radiograms taken with 6 months were graded according to the Larsen-Dale index, where 0 = normal and 5 = maximaijoint destruction [15]. Technical equipment. A strain gauge (Bofors, Karlskoga, Sweden) with a linear response between 0 and 4 000 Nm was used. To calculate the torque in Nm the distance between the ankle strap and the tibia condyle plateau was measured. E M G was recorded as full-wave rectified, low-pass filtered, and timeaveraged using DISA 05A02 equipment (DISA Electronik, Skovlunde, Denmark). The time constant was 0.8 s. Recording procedure day O. Local pain at rest and on movement was registered on two different 120 mm horizontal, anchored visual analogue scales (VAS) with end points "no pain" and "very severe pain." The knee circumference, midpatellar and 1 cm cranial to the patella, presence of lateral instability in the extended position, and the maximal voluntary extension-flexion range were recorded. The patient was positioned comfortably half-sitting on the examination bench with a sand bag under the knees and the hands resting on the belly. The knee flexion was 30 °. The strain gauge was attached to the leg of the examination bench with a chain and around the ankle with a strap. Two 1 cm
266 large silver electrodes at a distance of 2 - 3 cm were fixed over both the vastus medialis and the vastns lateralis portion of the quadriceps muscle. To identify the position of the electrodes in the subsequent registrations, their positions were marked on the skin. After two to three trials, five maximal isometric knee extensions were recorded. A local anesthetic was used subcutaneously (lidocaine 5 g/l), but care was taken not to inject any into the joint cavity. A 1.4 m m teflon cannula was inserted from the anterior lateral aspect into the suprapatellar recess, and the accessible synovial fluid was withdrawn and measured. Twenty mg of triamcinolone hexacetonid (Lederspan ®, Lederle) was injected into the joint cavity before cannula removal. Five maximal isometric knee extensions were performed, and the knee was put to rest till the following day. The patient was informed to resume normal daily activities, but not to perform specific knee muscle training. To evaluate the impact of joint aspiration alone, the same procedure as on day 0 was performed on day - 7 in the first five knee joints without glucocorticosteroid administration. Knee extensor torque, EMG, pain, knee circumference, and range of movement values were registered on day + 7 and + 14. F o r E M G and torque, the mean of the three highest values at each occasion was used. Due to variations between patients for the quantified E M G values a normalization was performed. The value before cannula insertion on day 0 was assigned "100%." The other values were calculated as percentages of this reference level. For statistical comparison between E M G and torque, the same normalization procedure was also performed for the knee extensor torque values. The difference of both torque and E M G before and after joint aspiration, as well as the difference before cannula insertion on day 0 and on days 7 and 14 (A-torque and A-EMG) have been used in some calculations (see Results). Stat&tics. Spearman's rank correlation coefficient was used as well as the Wilcoxon matched rank-sum test for paired samples in a two-tailed manner.
Results
Extensor torque, EMG, and range of motion had increased at day 7, whereas pain on motion and at rest as well as both mid- and suprapatellar knee
circumferences had decreased. Knee function at day 14 in some cases showed further improvement compared with day 7, whereas in most cases it was similar or had decreased slightly (Table 1, Figs. 1 and 2). In the five knee joints also subjected to arthrocentesis alone, torque on the whole remained unchanged after I week (Fig. 1). The extensor torque increased significantly (median A-torque 8.8 Nm, range -8.2 to 30.8, P
