Often dubbed "the black box of the wrist," ulnar wrist pain is a common, debilitating condition that frustrates both patients and practitioners. Mayo Clinic has developed a diagnostic algorithm designed to address the major components and enhance the management of distal radioulnar joint (DRUJ) conditions.
"The algorithm provides a systematic approach to ensure we characterize the most common elements of ulnar wrist pathology for complete treatment. In this way, we can hone in on the diagnosis or diagnoses and tailor the treatment to address the problem," says Sanjeev (Sanj) Kakar, M.D., an orthopedic surgeon at Mayo Clinic in Rochester, Minnesota. The algorithm was developed in conjunction with Marc Garcia-Elias, M.D., Ph.D., a specialist in carpal instability at the Kaplan Hand Institute in Barcelona, Spain.
The '4-Leaf Clover' algorithm
Ulnar wrist pathology is common and generally involves derangements to several structures. "Often only one component of the multiple pathologies is addressed, and the issue is that these aren't mutually exclusive. Continuing problems often frustrate patients and their treating providers," Dr. Kakar says.
As described in the April 2016 issue of the Journal of Hand Surgery, the Four-Leaf Clover algorithm focuses on four key factors. Physicians should ask if the DRUJ dysfunction is influenced by:
- Bone deformity, such as distal radius malunion or radioulnar length discrepancy
- Cartilage defect, due to factors such as arthritis
- The nature of the static stabilizers of the DRUJ, such as triangular fibrocartilage complex (TFCC) injury
- The quality of dynamic restraints such as the extensor carpi ulnaris (ECU) tendon and the possible presence of associated pathology
"The algorithm uses a Venn diagram to represent the different combinations of pathologies that can be present," Dr. Kakar says. "Overlapping zones enable the surgeon to think of the presenting problem in a multifaceted way and to offer the combination of treatments that best fulfills the patient's needs."
Dr. Kakar cites the example of athletes presenting with ulnar-sided wrist pain. Their pain is often due to a TFCC injury, but they may have concomitant injuries to other structures. Mayo Clinic is collaborating with the United States Tennis Association to try to prevent and treat these injuries.
"Using dynamic electromyography and high-speed cameras in our Motion Analysis Laboratory with Kenton R. Kaufman, Ph.D., Kathie A. Bernhardt and team, we've been able to look at muscles that are firing appropriately and inappropriately during the tennis stroke," Dr. Kakar says. "We want to find a normative data set and devise objective parameters of what these athletes need to achieve in order to return to competitive play."
The 'calamari procedure'
For people with DRUJ arthritis, ulnar head replacement can relieve pain and restore functional anatomy and kinematics. However, up to 30 percent of patients may need revision surgery, mostly due to implant instability and persistent pain.
Mayo Clinic surgeons, building on the clinic's tradition of innovation, have devised a technique that may help. Termed the "calamari procedure," the technique involves an ulnar head partial replacement with DRUJ interposition arthroplasty using a lateral meniscal allograft as a stabilizer. The allograft is trimmed to match the size of the sigmoid notch; the two edges of the meniscus are sutured together to form a ring, deepening the concavity of the sigmoid notch and thereby providing stability to the implant.
"I had the pleasure of working with Bassem T. Elhassan, M.D., an orthopedic surgeon at Mayo Clinic's campus in Minnesota, who, using the principles of shoulder surgery, devised this technique for the wrist," Dr. Kakar says.
In the July 2017 issue of the Journal of Hand Surgery (European Volume), Mayo Clinic researchers described favorable outcomes of patients who underwent the procedure. After a mean follow-up of 20 months, all patients experienced a marked reduction in pain and had an increase in postoperative range of motion, with an average increase in grip strength of 43 percent to the unaffected extremity. No patient reported symptoms of implant instability.
"The technique is still in its infancy, but Dr. Elhassan and I have been impressed with the results so far," Dr. Kakar says. "Patients with ulnar wrist pain can have difficulty with everyday things such as lifting a child out of a car seat. Sometimes the patients are labeled as having chronic pain and prescribed opioids. It can be soul destroying. At Mayo, working together, we hope we can help these patients return to a better life."
For more information
Kakar S, et al. The "Four-Leaf Clover" treatment algorithm: A practical approach to manage disorders of the distal radioulnar joint. Journal of Hand Surgery. 2016;41:551.
Kakar S, et al. Ulnar head replacement and sigmoid notch resurfacing arthroplasty with a lateral meniscal allograft: "Calamari procedure." Journal of Hand Surgery (European Volume). 2017;42:567.