A Case of Ulnar Positive Variance Found on X-ray

A Case of Ulnar Positive Variance Found on X-ray

SCIENTIFIC/CLINICAL ARTICLE JHT READ FOR CREDIT #056 A Case of Ulnar Positive Variance Found on X-ray Kenneth R. Flowers, PT, CHT Current Clinical ...

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SCIENTIFIC/CLINICAL ARTICLE JHT READ

FOR

CREDIT #056

A Case of Ulnar Positive Variance Found on X-ray Kenneth R. Flowers, PT, CHT Current Clinical Concepts, San Francisco, California

Paul C. LaStayo, PT, PhD, CHT University of Utah, Division of Physical Therapy, Salt Lake City, Utah

One of the best low-cost investments a hand therapist can make is in a simple x-ray view box. It will pay clinical dividends for years to come, an annuity of sorts. The definitive reading/interpreting of x-ray images is not strictly within the scope of our practice, but there are times when looking at these images will shed considerable light on what is happening clinically with your patient. The purpose of this brief article is to encourage you to look at x-ray images for overt findings that do not require subtle distinctions to be made, in hopes of gaining insight into the proper clinical course of action to be taken. The underlying assumptions that stimulate us to make this recommendation are that in our current practice settings, many of our patients are referred by sources other than fellowship-trained hand surgeons, and that many of these sources have had limited training in evaluating x-rays of the hand. Your knowledge of hand anatomy and biomechanics may well be superior to that of the referral source. If you can apply this knowledge to the viewing of basic musculoskeletal x-ray images, you may spot an otherwise unreported problem with your patient and take appropriate action, often in the form of a conversation with the referral source that will hopefully result in a new management plan for the patient, one consistent with the ‘‘new finding’’ on x-ray. To support our thesis, we offer an abbreviated case report for your consideration. Our case involves a 28-year-old male plumber with a diagnosis of ulnar-sided wrist pain of several

Correspondence and reprint requests to Kenneth R. Flowers, PT, CHT, Current Clinical Concepts, 875 La Playa #278, San Francisco, CA 94121; e-mail: . 0894-1130/$ e see front matter Ó 2007 Hanley & Belfus, an imprint of Elsevier Inc. All rights reserved. doi:10.1197/j.jht.2007.02.005

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ABSTRACT: A briefcase report is presented that demonstrates the advantage of the therapist’s viewing of a series of wrist x-rays in guiding the clinical management of a patient with an ulnar plus configuration. The positive findings revealed on these images facilitated an improved outcome. This case is offered to encourage therapists to routinely look at x-rays in their clinical practice. J HAND THER. 2007;20:148–51.

months’ duration, but no history of overt trauma, who was referred to hand therapy by an ‘‘occ-med doc.’’ The script asked for strengthening and modalities for pain control. On initial evaluation there was nothing remarkable except for the patient’s complaint of pain with gripping that resulted in diminished grip strength results on the dynamometer. The pain was localized by the patient as being on the ulnar side of the wrist, worse dorsally than volarly. Our first intervention was to provide a resting splint and instructions to ‘‘take the weekend off’’ from gripping activities (a so-called stress vacation) and to stop by the doctor’s office and pick up his xrays on the way in to his next therapy appointment. On that next visit, four days after the initial visit, the patient reported that his wrist was comfortable and that he had heeded our advice to ‘‘cool it’’ with his wrist. However, on grip strength testing, the pain was still significant. At this point, the films were put up on the view box; the PA x-ray can be seen in Figure 1. It should not take a board-certified radiologist or hand surgeon to see that our patient had a skeletal configuration called an ulnar plus (or positive) variance. The normal length relationship of the radius to the ulna is one in which the ulnar border of the articular surface of the distal radius lies in line with the distal surface of the ulna. In Figure 1, you can see that the ulnar surface is distal to the radial border, by perhaps 2e3 mm. Knowing that the normal force distribution across the wrist in axial loading (gripping) is approximately 80% down through the radiocarpal joint and 20% through the ulnar side of the wrist,1 and that in an ulnar plus variance substantially more load is imparted to the ulnar side, it was evident that this patient was overloaded on the ulnar side of the wrist when performing his duties at work. In fact, during any activity involving power grip in a pronated position, he was terribly uncomfortable.

FIGURE 1. Preoperative PA image demonstrating ulnar positive variance. Further, our training in joint biomechanics taught us that in the pronated forearm there is a normal shift in the direction of a positive ulnar variance.2 Therefore, as part of further evaluation we tested the patient’s grip, not only in forearm neutral, but in pronation and supination as well. Not surprisingly, we found there to be a significant effect on grip performance when testing in these three positions of the forearm. His grip in neutral was 95 lb, in supination 98 lb, and in pronation 63 lb. These data can also be expressed by dividing the supinated value by the pronated value, which provides a gripping rotatory impaction test (GRIT) ratio of 1.56, suggestive of an ulnar-sided lesion.3

FIGURE 2. Postoperative image demonstrating the plate on the osteotomy site on the ulnar shaft.

FIGURE 3. Static x-ray taken after the first ulnar shortening surgery demonstrating an apparent leveling of ulna vs. radius and the remnants of a screw hole on the ulnar shaft. The combination of the GRIT score and the ulnar positive x-ray made us very suspicious that this patient was suffering from ulnar impaction syndrome,4 which is quite common in the face of an ulnar positive variance. Our next task was to substantiate the clinical diagnosis. As a practical matter this was carried out through a phone call to the referring physician and a delicate discussion of our findings whereupon the physician suggested a hand surgical consultation. The hand surgeon

FIGURE 4. Dynamic x-ray in pronation and gripping taken after the first ulnar shortening procedure demonstrating an ulnar plus configuration. AprileJune 2007 149

quickly confirmed the diagnosis and asked us to continue to try conservative management to see if more rest and a ‘‘tincture of time’’ might calm things down. It is well known that not all ulnar plus patients require surgery. However, conservative efforts did not substantially relieve this patient’s pain, and after six weeks a surgical leveling procedure was carried out in the form of an ulnar shortening with a sixhole plate crossing the osteotomy site on the ulnar shaft (see Figure 2). The patient was referred back to hand therapy at 16 weeks postoperatively for ‘‘rehabilitation.’’ Why such a long time after the operation you might ask. The ‘‘delay’’ was because at 14 weeks post-op, the patient continued to complain of irritation along the ulnar border of his forearm, and the surgeon opted to remove the plate and screws in hopes of relieving this post-op pain. The procedure was successful in that the forearm pain resolved rapidly. Looking at Figure 3 you will see two important features. First, you will note the residual hole on the ulnar shaft that is not yet fully filled in after removal of the plate and screws, and secondly and more importantly, the apparent ulnar neutrality (correct length relationship between ulna and radius), which was the objective of the surgery. The apparent holes tell us that the bone is not fully healed and some caution should be employed when exercising the patient. Therefore, the rehabilitation proceeded slowly. Eventually, we were able to incorporate resistance exercise to restore strength. Up until then, the progress had been encouraging with range of motion returning at a predictable rate, i.e., swiftly. However, it became abundantly clear that heavy gripping, particularly in pronation, was not being tolerated by the patient, with a recurrence of ulnarsided pain similar to that reported in the original

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pre-op complaint. Once again, grip strength results and the resultant GRIT ratio (now 1.48) testing suggested that some structure on the ulnar side of the wrist remained irritated. This time we did not hesitate to call the surgeon and discuss our fears. Recall that Figure 2 is a static PA view showing apparent ulnar neutrality. Figure 4 is a dynamic (pronated and gripping) x-ray image that the surgeon ordered after our conversation. Once again, we see the ulnar positive result causing probable impaction. Eventually, the surgeon convinced the patient that further ulnar shortening was needed, and this was performed. This second shortening procedure did relieve his pain with gripping activities, allowing for successful rehabilitation and a resumption of his work. We hope that reviewing the highlights of this case brings home the message that viewing basic x-rays such as these AP images can make a difference in our strategies for managing our patients. This is just one among the many examples that exist for different clinical scenarios where therapists’ viewing of hand x-ray images can be a rewarding experience not only for them, but for their patients. We encourage you to become familiar with common x-ray findings and enhance your practice and improve patient outcomes.

REFERENCES 1. Palmer AK, Werner FW. Biomechanics of the distal radioulnar joint. Clin Orthop. 1984;187:26. 2. Palmer AK, Glisson RR, Werner FW. Ulnar variance determination. J Hand Surg. 1984;7:376. 3. LaStayo PC, Weiss S. The GRIT: a quantitative measure of ulnar impaction syndrome. J Hand Ther. 2001;14:173–9. 4. Friedman SL, Palmer AK. The ulnar impaction syndrome. Hand Clin. 1991;7:295–310.

JHT Read for Credit Quiz: Article #056 Record your answers on the Return Answer Form found on the tear-out coupon at the back of this issue. There is only one best answer for each question. #1. The article suggests that: a. hand therapists are certainly more qualified to interpret x-rays than general practice physicians b. the routine viewing of x-rays by hand therapists is illegal and is discouraged c. the definitive reading and interpretation of xrays is certainly within the scope of the practice of hand therapy d. routine viewing of x-rays by hand therapists can be a valuable clinical tool and is encouraged #2. The original presenting (to the therapist) diagnosis was: a. status postedistal radius fracture b. ulnar-sided wrist pain secondary to ulnar impaction syndrome c. ulnar-sided wrist pain of undetermined origin d. probable TFC tear #3. The therapist gained access to the patient’s x-rays by: a. having the patient obtain the films from the physician’s office

b. calling the physician to request a copy of the patient’s films c. going to the x-ray department of the hospital to pick up a copy of the films d. emailing the physician’s secretary requesting the films #4. The PA x-ray showed: a. impaction of the DRUJ b. a 2e3 mm length discrepancy between the radius and ulna, with the radius being too long relative to the ulna c. a 2e3 mm length discrepancy between the radius and ulna, with the ulna being too long relative to the radius d. a tear in the TFC #5. The therapist suspected a clinical diagnosis of ulnar impaction syndrome based on: a. the GRIT score b. a combination of the GRIT score and the x-ray appearance of ulnar positivity c. the x-ray d. the patient’s history

When submitting to the HTCC for recertification, please batch your JHT RFC certificates in groups of three or more to get full credit.

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