Tag Archive | ulna

The Challenges of Complex Revision Elbow Arthroplasty

Lower-extremity joint replacement is quite well-advanced, thanks to a high incidence of disabling osteoarthritis and a 40-plus-year history of development in hip and knee prostheses. Additionally, during the last 5 to 10 years, we have made progress in prosthetic design and reliable surgical techniques for the ankle. In the upper extremity, we have a similar 4-decade development history with anatomic shoulder replacement and now 10-plus years with increasingly reliable reverse total shoulder arthroplasty.

However, techniques for elbow and wrist arthroplasty have been much slower to develop, due to lower incidence of pathology, the unique functional demands on these joints, and prosthetic-design and fixation issues. Still, the Conrad-Morrey family of implants has provided reliable elbow prostheses for more than 20 years. Meanwhile, the indications for elbow arthroplasty have narrowed to inflammatory arthritis and distal humeral fractures and nonunions in patients with lower functional demands. Unfortunately, failure of fixation, infection, and bone resorption do occur after primary elbow arthroplasty; consequently, a small but growing number of patients face revision elbow arthroplasty.

In the November 18, 2020 issue of The Journal, Burnier et al. report the results of revision elbow arthroplasty using a proximal ulnar allograft-prosthetic composite to compensate for missing ulnar bone stock and triceps tendon insufficiency. They clearly explain the surgical technique and report their results among a 10-patient cohort, including details of the 6 cases that required reoperation.

JBJS will continue reporting results of revision joint arthroplasty because members of the orthopaedic community have to manage these very complex cases, and this type of information is helpful to guide treatment decisions and patient expectations. Equally important is the positive impact this information has on further development of surgical techniques and prosthetic designs. Close examination of failure is the fuel for innovative improvement.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Step-Cut Osteotomy for Ulnar Shortening

Step Cut.gifUlnar shortening osteotomy is a widely accepted procedure for surgical treatment of ulnar impaction syndrome, but many techniques require special instrumentation to achieve accurate shortening, adequate fixation, and sufficient rotational control. In the November 2, 2016 issue of The Journal of Bone & Joint Surgery, Papatheodorou et al. report on outcomes in 164 patients who underwent so-called “step-cut” osteotomies for positive ulnar variances that ranged from +1 to +6 mm.

The technique itself, which utilizes a standard neutralization plate and lag screw for fixation, is summarized and illustrated in the article. The authors emphasize that the step-cut approach does not require special jigs or instrumentation.

Patients were followed for a median of 66 months. The overall union rate was 98.8%; postoperative ulnar variance ranged from –1 to +1.5 mm after a mean overall ulnar shortening of 2.5 mm. All patients had significant postoperative improvements in pain, range of motion, grip strength, and Mayo Modified Wrist Score. Plate removal due to irritation was necessary in only 12 (7.3%) of the patients.

The authors also found in these patients “a lower rate of degenerative changes at the distal radioulnar joint compared with rates reported in previous studies.” They attribute this to the relatively small amount of ulnar shortening with the step-cut procedure, which they surmise “diminishes the rate of articular incongruity and hence arthritis of the distal radioulnar joint.” On the cost side of the matter, the authors noted that at their institution, special ulnar osteotomy systems cost almost 10 times more than a standard neutralization plate.

JBJS Editor’s Choice—Anatomy: A Variable Key to Success in Orthopaedics

Forearm Rotation_7_6_16.gif

In the July 6, 2016 issue of The Journal, Weinberg at al. carefully measure the rotational profile of 600 cadaveric human forearm bones. The precision of these measurements is outstanding and sets a new standard for this type of investigation. The authors put real numbers on the rotational relationships between the radius and ulna that Evans first proposed in JBJS in 1945—and that many surgeons have relied on for intraoperative assessments of forearm rotational alignment since then.

What this investigation documents is the wide range of rotational profiles in the human forearm, with broad standard deviations. It confirms what all clinicians experience every day—each patient’s anatomy is different. There is commonality in hard- and soft-tissue structure overall, but the range of size, shape, density, length, and rotation is patient-specific and highly variable.

Whether closed, percutaneous, or open methods are applied, the skill and experience of the surgeon trump radiographic rules/tips/guidelines. As is often said with fracture reduction, the surgeon is responsible for 80% of the outcome. Studies comparing different casting methods or fixation devices provide useful information that address the remaining 20%, but surgical technique and surgeon experience/judgment are the major determinants.

We must always remember that each patient is not only emotionally and socially unique, but also anatomically unique. Our job is to restore their individual anatomy to the best of our clinical ability.  I am therefore not sure that repeating high-precision measurements of other osseous structures—only to re-confirm anatomic variability—will have much ultimate value for our community.

Marc Swiontkowski, MD
JBJS Editor-in-Chief