Manuel Alanis | UNAM Universidad Nacional Autónoma de México (original) (raw)

Papers by Manuel Alanis

13 The wrist has often been described as an irrelevant articulation that can be fused without cau... more 13 The wrist has often been described as an irrelevant articulation that can be fused without causing much functional impairment to the upper extremity. Undoubtedly, patients with a fused wrist may recover enough grip strength so as to return to their previous occupation; their hands, however, will never be completely normal. 77 A stiff wrist does not allow, for instance, washing one's own back, dusting a low surface, turning a steering wheel, or beating an egg without overloading the adjacent upper limb articulations. If the wrist is fused, the hand can reach distant objects, but it cannot be properly oriented to grasp, push, or manipulate them effectively. Certainly this is one of the most important roles of the wrist: to place the hand in the position that ensures its maximal efficiency with minimal energy cost. If properly identified and treated, wrist injuries tend to heal without sequelae, with a very low complication rate. When there is a complication, the carpus may remain aligned or it may collapse in a variety of ways. The articular cartilage may deteriorate or remain normal and asymptomatic. Identifying which injuries will evolve into significant dysfunctions is not always easy. How does one prevent an injured wrist from becoming unstable? How does one differentiate between carpal instability and carpal misalignment? There are no good answers to these questions; certainly, the more these subjects are analyzed, the more unknowns arise, leading to the realization that further research is needed. Progress is being made, however, and the proof can be found in this chapter. Only 5 years have passed since the sixth edition of this book was published, yet most chapters have had to be extensively rewritten. The goals have been: (1) to incorporate new knowledge acquired during this period, (2) to propose changes to the classification of carpal disorders, (3) to question misleading terminology, and (4) to eliminate concepts that the test of time has proved obsolete. The book's title itself has been modified to emphasize the fact that not all carpal misalign-ments are necessarily unstable, and that normal alignment does not guarantee stability. 2 Undeniably, there is a growing interest in the wrist. What follows is an earnest attempt to respond to that interest by offering an updated description of how to assess and treat the various disorders of the wrist, truly one of the most complex joints of the human body. Terminology. Most terms used to describe carpal misalign-ment and wrist instability were introduced in the 1970s, when these subjects were discussed for the first time. 57 Some of them have passed the test of time and are still useful and widely utilized ; others have been proven less effective, if not misleading or totally incorrect, and need to be revised. The following are some suggestions in this regard. The goal is to improve the clarity of what is taught and to avoid misinterpretation of the facts. The term rotary (or rotatory) instability of the scaphoid, 116 used to describe the advanced stage of carpal collapse where the scaphoid has lost its oblique alignment relative to the radius, is not correct: The scaphoid not only undergoes flexion and pro-nation but also translates dorsolaterally. There is never a pure rotation as implied by the adjective "rotary" or "rotatory." Furthermore , such an advanced stage of misalignment involves not only a complex displacement of the scaphoid but also of the lunate, which should be mentioned as well. The terms dorsal intercalated segment instability (DISI) and volar intercalated segment instability (VISI) 42 seem quite appropriate for cases where the entire proximal carpal row adopts a position of abnormal extension or flexion in relation to the long axis of the radius. However, its use to define deformities secondary to dissociative carpal instabilities may create some These videos may be found at ExpertConsult.com: 13.1 Dorsal view of a dissected cadaveric wrist set in a jig that allows isometric loading of different tendons. The entire scapholunate (SL) ligament complex has been sectioned. When the extensor carpi ulnaris (ECU) tendon is loaded, the distal row pronates and pulls the scaphoid away from the lunate. By contrast, loading of the extensor carpi radialis longus (ECRL) and abductor pollicis longus closes the SL gap. Certainly, the latter, and not the ECU; are the muscles that need to be emphasized when performing proprioceptive exercises for SL dissociations. (Cour-tesy of Marc Garcia-Elias and Alberto L. Lluch.) 13.2 Dynamic 3D computed tomography (also known as 4D computed tomography) of a patient with a scapholunate dissociation while performing dart thrower's exercises. Note that the scaphoid no longer behaves as a proximal row bone. It moves as if it were an extension of the distal carpal row; thus, the formation of a large gap in ulnar-flexion. (Courtesy of Marc Garcia-Elias and Alberto L. Lluch.) 13.3 Clinical example of a catch-up clunk phenomenon in a patient with carpal instability nondissociative-volar intercalated segmental instability. (Courtesy of Marc Garcia-Elias and Alberto L. Lluch.) 13.4 Volar approach of a perilunate dislocation. The distal surface of the lunate bone may be seen before the dislocation is reduced. (Courtesy of Marc Garcia-Elias and Alberto L. Lluch.) Descargado para Anonymous User (n/a) en Universidad Nacional Autonoma de Mexico de ClinicalKey.es por Elsevier en mayo 15, 2018. Para uso personal exclusivamente. No se permiten otros usos sin autorización.