Alternative Methods of Management

Alternative options for patients with stage D5 who do not have significant osteoarthritis but do have a humpback deformity include a palmar trapezoidal non-vascularized bone graft, a palmarly placed corticocancellous vascularized graft, and a salvage procedure. Salvage procedures include radial styloidectomy, scaphoid excision and midcarpal fusion, and radiocarpal arthrodesis.

A dorsal or palmar approach can be used. A palmar approach offers the advantages of excellent visualization, easier correction of a humpback deformity, and ability to compress the fracture fragments with a compression jig such as the Herbert jig. The palmar approach is applicable for most nonunion patterns except for fractures with small proximal pole fragments that would be difficult to engage with the end of the fixation used. The dorsal approach is better reserved for the cases of small proximal pole fragments or when other procedures such as vascularized bone grafting dictate a dorsal approach.

A complete range of fixation options exists. Options include no fixation, K-wire fixation, and compression-screw fixation with or without K-wire augmentation. Inlay bone grafting without internal fixation is appropriate when the fracture is stable, but without internal fixation early range of motion will not be possible. K wires are easily placed, inexpensive, and can be removed for postoperative imaging; however, they do not create compression at the fracture site.

Compression screws all provide security for earlier range of motion. Also, they allow compression with screw placement, but necessarily have the associated risk of flexing the fracture if the screw is placed poorly or there is inadequate palmar support. Additionally, compression screws have added expense and require additional technical skills.

When applicable, the conventional noncannulated Herbert screw offers many advantages. Rigid internal fixation is possible, thus providing added security for earlier range of motion or a longer period of implant integrity for slow healing situations. The Herbert jig allows for compression across the osteosynthesis site prior to screw placement, and it is more easily placed than the more bulky jig for the Herbert-Whipple cannulated screw. Because the core area at the osteosynthesis site is smaller than that of the Herbert-Whipple screw, more bone contact area remains for osteosynthesis. In contrast to an Acutrak screw, the threads on each end of a Herbert or Herbert-Whipple screw are uniform (i.e., constant pitch). Thus, there is minimal resistance during advancement of the screw through the "upstream" fragment (proximal relative to the screw) during the screw insertion. With minimal resistance, the screw imparts minimal torsional force to the "upstream" fragment, and subsequently there is less tendency for rotation at the osteosynthesis during insertion than with the placement of an Acutrak screw. Situations where a Herbert screw is not optimal include fixation of a very small proximal pole fragment and when postoperative imaging is anticipated such as with a vascularized bone graft.

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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