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Anterior-posterior x-ray of the patient’s wrist
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Lateral x-ray of the patient’s wrist
A 57-year-old man presents with several years of right wrist pain. He believes the pain started after a dirt bike accident when he was in college, as he recalls falling off his bike onto his outstretched hand. He never sought medical attention after the injury and has had pain off and on since then. He reports that the pain seems to have gotten worse over the last 2 weeks and he is having increasing weakness with his golf swing. X-rays of the wrist taken recently at an urgent care facility show chronic degenerative changes of the wrist associated with prior avascular necrosis of the scaphoid. The patient had minimal relief from prior wrist injections that he received 2 years earlier.
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The x-ray reveals that the patient sustained a scaphoid fracture years ago, and as a result of nontreatment, developed a chronic scaphoid nonunion and wrist arthritis. X-ray findings are consistent with a scaphoid nonunion advanced collapse (SNAC) wrist.
Patients with a SNAC wrist will complain of decreased range of motion and weak grip strength. Active wrist extension becomes very painful, and patients are often unable to perform a pushup. Early x-ray findings may include beaking of the radial styloid, which is often followed by radioscaphoid arthritis. Progression of the disease results in radioscaphoid and capitolunate arthritis, followed by pancarpal arthritis.
Bone grafting and internal fixation is contraindicated in patients with advanced arthritis like the patient in the introductory case. A radial styloidectomy may have been useful early in the disease process to help relieve pain and improve range of motion associated with radioscaphoid impingement. However, degenerative changes are noted in the midcarpal joint, which would not be addressed with a radial styloidectomy alone.
The patient’s capitate shows subchondral cyst formation and degenerative sclerosis. A proximal row carpectomy should be avoided in patients with degenerative changes of the capitate. A degenerative capitate may result in pain when articulating with the distal radius; therefore, a proximal row carpectomy is not a good option.
The most appropriate treatment option for this patient would be a scaphoid excision with a four-corner fusion. The carpal bones fused would include the lunate, triquetrum, capitate, and hamate. The indication for a four-corner fusion is pain relief, and patients should be advised that additional loss of grip strength and motion is likely postoperatively. Four-corner fusion has been shown to retain 60% of wrist motion and 80% of grip strength, compared to preoperatively. A total wrist arthrodesis has predictable pain relief with wrist arthritis but at the expense of eliminating radiocarpal motion.
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor in chief of the Journal of Orthopedics for Physician Assistants (JOPA).
References
- SNAC (Scaphoid Nonunion Advanced Collapse). Orthobullets Web site. Updated August 31, 2015. Accessed October 20, 2015. www.orthobullets.com/hand/12119/snac-scaphoid-nonunion-advanced-collapse
- Trumble TE, Waitayawinyu T. Advances in the treatment of scaphoid nonunions. Orthopedic Knowledge Online Journal. Accessed October 20, 2015. http://orthoportal.aaos.org/oko/article.aspx?article=OKO_HAN033#article
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