Complications of tendon injuries

Missed tendon injuries can occur when either the patient or the initial examining physician fails to appreciate subtle findings.

Partial tendon lacerations (partend.htm) should be suspected when the patient has apparent full motion, but has pain when attempting to use the tendon against resistance.  Consequences of partial tendon lacerations include delayed rupture, scarring with tendon adhesions, triggering and weakness.

Missed finger extensor mechanism injuries may occur because the broad expanse of the extensor mechanism can initially maintain posture until softening from the healing process allows the remnants of support to give way.  Terminal tendon injuries at the distal interphalangeal joint, and central slip injuries at the proximal interphalangeal joint should be suspected when there is a regional injury and pain with attempted extension against resistance, even if the patient has a full active unresisted motion.

Missed finger flexor tendon injuries are less common than missed extensor tendon injuries because of change in the resting posture of the hand  (cuttend.htm). Isolated superficialis tendon injury with an intact profundus tendon produces a subtle change in finger posture, and is easily missed.  Profundus tendon avulsion injuries (profavul.htm) are often unappreciated by the patient, who believes that the finger is simply "jammed", and delays medical evaluation until the best window of opportunity for treatment has passed. If there is significant proximal retraction after profundus avulsion, the flexor tendon sheath fills with blood, and within a matter of days shrinks enough that reinsertion is either impossible or does not result in functional movement.

Missed dorsal hand extensor tendon injuries may occur with little initial functional deficit, either through action of adjacent tendinous junctures, or in the index or small fingers if only one of two (proprius and communis) tendons has been cut. Extensor pollicis longus tendon injuries may be missed because of trick motion through the action of the thumb intrinsic muscles on the thumb extensor mechanism, which may allow interphalangeal joint extension to neutral despite a divided extensor pollicis longus tendon.

Common complications of tendon injuries of the hand include stiffness, contractures, tendon rupture, recurrent adhesions and weakness, and depend on the exact level of injury.
The worst results of flexor tendon injuries occur in injuries located in the flexor tendon sheath extending from the metacarpal head to the middle portion of the middle phalanx - referred to as "zone II" or "no man's land". Even under ideal management, only about half of injuries at this level recover good to excellent function, and fewer have a satisfactory outcome following staged flexor tendon reconstruction with a tendon graft (CJ). Quadrigia syndrome refers to limited excursion of the middle, ring, and small fingers due to tethering connections between the profundus tendons of these fingers.  This may follow a simple flexor tendon injury or be due to adhesions following amputation.

The worst results of extensor tendon injuries occur when injuries are located over the dorsum of the proximal phalanx  or the proximal interphalangeal joint. Loss of proximal interphalangeal joint motion may take the form of a fixed contracture, swan neck deformity, or boutonniere finger. Thin soft tissue cover and poor tolerance of any length change both contribute to poor results at this level.

Complications of the treatment of tendon injuries
Tendon adhesions and are the most common problem following tendon repair. Rupture of a flexor tendon repair occurs in at least four percent of patients following primary flexor tendon repair in zone II with postoperative controlled passive motion (CJ). Stiffness may be due to either or both problems, and it may be impossible to determine the nature of loss of motion, even with MRI.

Mallet finger: Nearly half of patients treated for mallet finger develop some type of complication of treatment.  Complications following surgery are more common, more serious (e.g. deep infection), and more frequently permanent than those arising from splinting alone (BG).

Bowstringing due to incompetence of the flexor tendon pulley system may follow injury or iatrogenic injury during efforts to expose, retrieve, and repair the tendon.  External ring splints to support the tendon pulley system are commonly used, but have not shown to be mechanically effective in preventing bowstringing.

Staged flexor tendon reconstruction using temporary silastic tendon spacers followed by tendon grafts carry all the risks of primary tendon repair.  In addition, staged reconstruction is more likely to result in flexion contractures, and greatly extend the necessary length of incapacitation.
e-Hand Previous Next Search Chapter Textbook