In Reply

Abstract

We thank Dr. Gohritz and his colleagues for a very thoughtful review of our manuscript. We hope that our letter of response will help to highlight the relatively straightforward and simple conclusion from our manuscript, which is that ultrasound can provide an accurate means of diagnosing extensor carpi ulnaris (ECU) subluxation and that anatomic repair of the retinaculum can provide relief of symptoms and improve patient satisfaction for this fairly rare cause of ulnar wrist pain. We conclude that the repair of the ECU sheath corrected and relieved pain but did not provide clinically significant improvement in range of motion and grip strength—as one might suspect, given that the integrity of the joint is not altered by correcting the subluxation of the extensor carpi ulnaris. In order to respond to the author's specific questions we note the following:1Although the questionnaire for the Disabilities of the Arm, Shoulder, and Hand (DASH) is validated and standardized, the methods for recording the data have not been standardized. Depending on the manuscript the data has been recorded either an average of 1- to 5-point response; the total score can range from 30 to 150 or a corrected DASH score to fit a 0- to 100-point scale. In the initial manuscript, we reported the raw data collected by our research assistants. After correcting the data to a 100-point scale we would note that our preoperative DASH score was 56.03 ± 15.80 and the postoperative DASH score was 23.41 ± 11.43, which still has a statistically significant difference of p < .001.2The grip strength data were actually a set of continuous variables without a normal distribution and therefore we analyzed them by the Wilcoxon signed-rank test. The median of the preoperative and postoperative grip strength was 34 and 36 kg, respectively. This did result in a statistically significant difference of p = .003, because of the small variability in the data; we do acknowledge that this statistically significant difference is not clinically significant.3We use the American Medical Association (AMA) guidelines designed for measuring impairment; we should have used the AMA guidelines for measuring range of motion. We used a calibrated goniometer with a research assistant, trained in the measurements, who had to reproduce both measurements within ±1°.4The physicians who performed the ultrasonography were highly trained with this technique. Although we did not report an intra- and inter-reader reliability score, we note that the ultrasonographers did evaluate the contralateral uninjured side. We defined ECU subluxation and dislocation only if the ECU completely displaced out of the osseous groove on the injured side compared with normal studies of the opposite side showing no displacement of the ECU with pronation and supination. In summary, we are pleased to be able to emphasize the relatively straightforward conclusion from our data. Ultrasound provides a good diagnostic test of extensor carpi ulnaris dislocation, and anatomic repair of the sheath helps to relieve the patient's symptoms and improve his or her overall quality of life after this fairly uncommon cause of ulnar wrist pain. Extensor Carpi Ulnaris Subluxation: A Problem of Significance?Journal of Hand SurgeryVol. 33Issue 9PreviewWe read with astonishment the recent report by Dr. MacLennan and coworkers on “Diagnosis and Anatomic Reconstruction of Extensor Carpi Ulnaris Subluxation” in 21 patients aged between 14 and 44 years.1 The authors concluded that extensor carpi ulnaris stabilization significantly “improved postoperative wrist range of motion, grip strength, pain, satisfaction, and DASH scores.” We think that this conclusion deserves some comments. Full-Text PDF