Traumatic rupture of the extensor tendons at the musculotendinous junction.

Ten cases of closed extensor tendon rupture at the musculotendinous junction are reported. In five patients the rupture occurred at work, and in five during athletic activities. In each instance, indirect tendon injury resulted from a strong stretching force applied to a contracting muscle. In one case, rupture of the extensor pollicis longus tendon occurred proximal to the extensor retinaculum. In eight cases of complete tendon rupture direct repair was impossible. Of these eight patients, five were treated by side-to-side juncture and three by tendon transfer. Two patients with incomplete rupture were treated by splinting. All patients improved after treatment.