An Experimental Study Comparing Active Mobilization to Passive Flexion–Active Extension–Active Flexion After Flexor Tendon Repair in Zone 2

PurposeBoth passive flexion–active extension and active rehabilitation have shown advantages and disadvantages in tendon healing. The purpose of this study was to measure the effect of a combination of these 2 rehabilitation protocols.MethodsA tendon injury model was used in white Leghorn chickens. Thirty-two animals were randomly assigned into 4 groups. We compared an unrestricted active flexion rehabilitation (UA) group with 3 groups starting passive flexion, active extension, and active flexion (PAA) at 5, 9.5 and 14 days after repair. The tensile properties and range of motion of the 3 interphalangeal joints were evaluated for 3 postoperative weeks.ResultsIn terms of tensile properties of the operated foot, PAA-14 was higher than any other group, and PAA-5 was the lowest. There was no significant difference between the PAA-9.5 and UA. For the range of motion, there were significant differences between all 4 groups: UA increased the most, PAA-14 increased the least, and PAA-5 increased more than PAA-9.5. For the rupture rate, UA and PAA-5 were higher than were PAA-9.5 and PAA-14.ConclusionsThe results indicate that the PAA-9.5 and UA may give the best balance (tensile properties, range of motion, rupture rates) of these rehabilitation protocols. PPA-9.5 and UA had similar moderate tensile properties. When considering an increased range of motion, the UA method may be the most appropriate despite its higher rupture rate. When considering a lower rupture rate, PAA-9.5 may be the most suitable.Type of study/level of evidenceTherapeutic III.