Comparison of muscular and articular factors in the progression of contractures after spinal cord injury in rats

Abstract

Study design: Experimental, controlled trial. Objectives: To identify the relationship between the muscular and articular factors in the progression of contractures after spinal cord injury (SCI). Setting: Hiroshima University, Hiroshima, Japan. Methods: In total, 48 female Wistar rats were used. The 24 experimental rats that underwent a spinal cord transection and the other 24 control rats that underwent a sham-operation were assessed at 2, 4, 8, 12, 16, or 24 weeks postsurgery. Knee joint motion was measured for flexion and extension. Myotomy of the transarticular muscles was then performed and range of motion was measured again. The degree of contractures was assessed by goniometry measuring the femorotibial angle before and after the myotomies. Results: The spinal cord-injured rats demonstrated flaccid paralysis during the first few days postsurgery and thereafter spastic paralysis. Intra-and inter-rater reliabilities for all measurements were 40.814. Knee flexion contractures developed in the all experimental rats, and progressed for the first 12 weeks and plateaued thereafter. Both the muscular (4875%) and articular (5275%) factors contributed almost equally to the overall progression of the contracture. Conclusion: The present findings may shed light on the underlying pathophysiology of contractures and should help guide research towards finding the elucidation of contracture development after SCI.

Remobilization Does Not Restore Immobilization-Induced Adhesion of Capsule and Restricted Joint Motion in Rat Knee Joints

“…combined arthrogenic and myogenic restriction at first measurement, and then, arthrogenic restriction was measured after resection of the periarticular muscles Moriyama et al 2006). In these methods, arthrogenic structures may be damaged at the first measurement, which influenced the second measurement of the arthrogenic component (Trudel et al 2008).…”

“…The factors responsible for joint contracture are mainly divided into the muscles (myogenic) and the periarticular structures (arthrogenic) (Evans et al 1960;Enneking and Horowitz 1972;. Recent studies indicated that the arthrogenic factors, especially the joint capsule, played an important role in the progression of limited range of motion after immobilization Moriyama et al 2006;Lee et al 2010). We revealed in the previous report that the arthrogenic limitation occurred after a 4-week immobilization in a rat immobilized knee model and the restricted motion was restored after incision of the capsule, which indicated that the joint capsule was one of the most responsible factors of limited range of motion after immobilization (Chimoto et al 2007).…”

Contrasting alteration patterns of different cartilage plates in knee articular cartilage after spinal cord injury in rats

“…[5][6][7]9 The eight SCI animals were anesthetized by intraperitoneal administration of 40 mg kg À1 sodium pentobarbital. After the spinal cord was exposed by a laminectomy of the T8 vertebra, it was completely transected at the level of T8.…”

“…Rectangles (30 mm deep and 400 mm long) were superimposed to the superficial and deep cartilage. Intense [5][6][7] Therefore, the FA cartilage corresponds to unapposed regions (no contact between cartilage surfaces) of the flexed knee. The FP, TA and TP regions are located at apposed regions (where the articular cartilages of two bones contact each other).…”

“…[1][2][3] The joints after SCI have been described as undergoing contractures, [4][5][6][7] osteoarthritis, 2 alterations of the periarticular connective tissue, 4,5 joint space narrowing and periarticular osteoporosis. 8 Several studies have also been reported the influence of SCI on the articular cartilage of the knee joint.…”