The achilles functional index

Abstract

The literature regarding the management of spontaneous rupture of the Achilles tendon is controversial and confusing. The relative infrequency of the condition in any one center prohibits the completion of well-designed clinical studies. Many of the disputes could be addressed and innovations tested if an appropriate animal model were available. We present a method for evaluating Achilles tendon function from measurements of the prints, preserved in bromphenol-blue-impregnated photocopying paper, of the hindfeet of walking rats. The stimulus for this study was derived from de Medinaceli's method for assessing the functional condition of rat sciatic nerves (de Medinaceli L, Freed WJ, Wyatt RJ: An index of the functional condition of rat sciatic nerve based on measurements made from walking tracks. Exp Neurol 77:634-643, 1982). Four variables were measured from these walking tracks, and comparisons between the damaged (experimental) and intact (normal) side were converted to proportional deficits. The relative contribution of each parameter to the overall deficit was determined by multiple linear regression analysis, and the variables were weighted accordingly to obtain an "Achilles Functional Index" (AFI). A sham operation produced no functional deficit, whereas animals subjected to a 0.5-cm midsubstance Achilles tendon defect demonstrated a markedly impaired AFI. Animals with repaired transected Achilles tendons also demonstrated a significant, but less severely impaired AFI. The functional deficit in this repair group returned to control values by postoperative day 15, whereas animals with a defect remained impaired at day 15. Furthermore, an excellent correlation was found between the functional recovery and biomechanical properties (ultimate failure load) of the healing tendon (r = 0.94; p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin-Like Growth Factor I Accelerates Functional Recovery from Achilles Tendon Injury in a Rat Model

“…Our investigational model is well established. 7,30,31 The IGF-I showed a clear impact on the functional recovery from tendon transection in this model. The impact was noted on the initial postoperative day.…”

“…Biomechanical testing was undertaken using a modification of the method developed by Murrell et al 30 Rats used for sham and transection were sacrificed at day 15 postoperatively. Hindlimbs were removed at the hips, flash frozen in liquid nitrogen, and stored at Ϫ20°C.…”

“…[1][2][3][4] In vivo, IGF-I is locally increased after tendon injury in a rat model, suggesting a role in the tendon repair process. 21 The rat Achilles tendon injury model as developed by Murrell et al 30 provides a rapid and economical vehicle to study the influence of various therapeutic modalities on tendon healing. In this model, the rat Achilles tendon is transected midsubstance on the right hindlimb, while the left hindlimb is left intact.…”

Characteristics of Proton NMR T2 Relaxation of Water in the Normal and Regenerating Tendon.

“…The plantaris muscle of the rabbit, which runs just medial to the Achilles tendon, is well developed and its diameter is approximately one-third that of the Achilles tendon. If we left the plantaris tendon intact, it might have acted as an "internal splint" [19]. For this reason the tendinous portion of the plantaris was transected to prevent this possibility.…”

Experimental model of Achilles tendon injury in rats

“…These conditions have been simulated through partial lesion, partial tissue laceration, tendinitis, tendinosis, transecctions, hole punction, incisional wound, dropping, total transection, longitudinal lesion and hemisecction on Achilles tendon [2][3][4][5][6][7][8][9][10][11][12] . Techniques to prevent injury or accelerate healing after injury can be tested in these models.…”