Traumatic Extensor Tendon Injuries to the Hand: Clinical Anatomy, Biomechanics, and Surgical Procedure Review

Abstract

The extensor apparatus is a complex muscle-tendon system that requires integrity or optimal reconstruction to preserve hand function. Anatomical knowledge and the understanding of physiopathology of extensor tendons are essential for an accurate diagnosis of extensor tendon injuries (ETIs) of the hand and wrist, because these lesions are complex and commonly observed in clinical practice. A careful clinical history and assessment still remain the first step for the diagnosis, followed by US and MR to confirm the suspect of ETI or to investigate some doubtful conditions and rule out associate lesions. During last decades the evolution of surgical techniques and rehabilitative treatment protocol led to gradual improvement in clinical results of ETI treatment and surgical repair. Injury classification into anatomical zones and the evaluation of the characteristics of the lesions are considered key points to select the appropriate treatment for ETI. Both conservative and surgical management can be indicated in ETI, depending on the anatomical zone and on the characteristics of the injuries. As a general rule, an attempt of conservative treatment should be performed when the lesion is expected to have favorable result with nonoperative procedure. Many surgical techniques have been proposed over the time and with favorable results if the tendon injury is not underestimated and adequately treated. Despite recent research findings, a lack of evidence-based knowledge is still observed in surgical treatment and postoperative management of ETI. Further clinical and biomechanical investigations would be advisable to clarify this complex issue.

Extension Mechanism of the Proximal Interphalangeal Joint of the Human Phalanx: A Cadaveric Biomechanical Study

“…The extensor mechanism of the finger is a complex and layered system that changes its geometry with flexion and extension [ 12 ]. The intrinsic extensor system, composed of the interosseous and lumbricals, forms the lateral bands and joins the extensor mechanism at the proximal third of the proximal phalanx [ 4 , 13 ].…”

The Role of High Frequency Ultrasonography in Diagnosis of Acute Closed Mallet Finger Injury

“…Furthermore, as we all know compared to MRI, ultrasonography was a quicker, more affordable, and less stressing screening choice 11 – 14 . So we can observe the thickness change of injured extensor tendon after treatment by ultrasonography, which is also an important aspect in the following-up 15 , 16 . As time goes on, the thickness of injured extensor tendons could decrease gradually with the swelling lightening.…”

Degenerative lesion of the extensor tendon V finger: Ultrasound imaging in diagnosis and therapeutic possibilities

“…Imaging is important in diagnosis [ 8 , 9 ], x-ray plays its role in the evaluation of bone injuries such as fractures possibly associated with the tendon injury and in the detection of radiopaque foreign bodies [ 10 ]. In addition, it may highlight predisposing factors for chronic hand tendon injuries such as maladjustment consolidated fractures.…”

“…In addition, it may highlight predisposing factors for chronic hand tendon injuries such as maladjustment consolidated fractures. Like x-ray, CT is also not adequate for direct evaluation of tendons and its application is limited to the suspicion of bone lesions to be investigated [ 9 , 10 ]. The most accurate methods for direct assessment of tendon structures of the extensor of the little finger are MRI and high resolution ultrasound.…”