An Experiential Rebuttal
The authors observed no difference in their gross or histologic evaluation of the flexor tenosynovium removed from patients with idiopathic carpal tunnel syndrome (CTS). In addition, no clinical difference was found in the results of 88 patients with or without flexor tenosynovectomy. These conclusions provide an opportunity to discuss their statement: "controversy still exists regarding the pathophysiology and treatment of idiopathic carpal tunnel syndrome."
In my view,the authors’ conclusion, according to the data presented, that routine flexor tenosynovectomy offers no benefit compared with sectioning of the transverse carpal ligament for the treatment of idiopathic carpal tunnel syndrome is not well founded,and cannot be inferred by finding no relationship between the gross and histologic findings. The use of a self reporting questionaire is also less than optimal.Therefore, I believe the conclusions reached by the authors are potentially misleading.
Also disappointing is the omission of a video supplement that shows the authors technique. The opportunity to observe the authors’ surgical tenosynovectomy technique would have been interesting.
Major points which are superbly addressed are:
1. The widespread incidence of CTS and its treatment by surgery;
2. The common reference to flexor tenosynovial hypertrophy as an "-itis";
3. The cause of CTS may be the "result of a decrease in the size of the carpal canal or an increase in the volume of the contents of the canal"; and
4. The possibility of a vicious cycle…. that leads to chronic tenosynovial thickening and fibrosis.
Dr. Strickland’s commentary and perspective on the eJBJS.org website eloquently reviewed a history of the pathophysiology of CTS and suggests that the condition is not an inflammation. In addition, he states "it remains likely that increased pressure in the carpal tunnel results from increases in the volume of the canal’s contents with the flexor tenosynovium still being the prime suspect." He renders no opinion regarding the conclusion of Shum’s article.
My interest in radical palmar flexor tenosynoctomy after release of the flexor retinaculum (referred to by the authors as the transverse carpal ligament) came from years of experience in the treatment of CTS in a workers’ compensation practice setting. My curiosity began early on when I was surprised by a patient, who was undergoing carpal tunnel release (CTR) under local anesthesia, complaining of pain when the flexor tenosynovium was manipulated. I remembered being taught that the tenosynovium was thought not to have pain fiber innervation, and was therefore, not to be considered as a source of pain. I also recalled the success of rheumatoid tenosynovectomy leading to a lower rate of recurrence than synovectomy of a joint.
I use an incision that begins distally at the level of the superficial arch and extends proximally to (exactly) the distal transverse wrist flexion crease (the authors note that their incision "stops short" of this crease). In addition, the proximal margin of the flexor retinaculum along with the distal contiguous volar antebrachial fascia is released subcutaneously for a distance of 7-8 cm.
Removal of the flexor tensosynovium begins as far proximal as the distal muscle bellies of the FDS. An incision along the ulnar aspect of the median nerve is made exactly at the interval between it and the tenosynovium. All the tenosynovium is initially removed beginning proximally with all fingers in full extension and finishing distally with the fingers in full flexion to the mid-lumbrical level. When the procedure is completed, denuded tendons are clearly visible. Tourniquet time on average is twenty-five minutes. (I should add that I have never experienced flexor tendon adhesions or loss of motion as suggested as a possible complication by Dr. Strickland; perhaps aggressive active range of motion that is initiated by the patient in the recovery room and continues throughout the early post-operative period is responsible).
The volume and amount of the tenosynovial specimen can be larger than what was expected at the start of the procedure. I agree with the authors’ statement regarding the difficulty in predicting the amount of material to be removed based on the gross appearance.
The histology of the flexor tenosynovium is not the issue in idiopathic CTS. The issue is the volume of the tenosynovium to which Dr. Strickland and others have alluded. Pre-operative assessment of the presence of hypertrophic tenosynovium can be made with a physical examination. This can be accomplished by observing fullness of the volar wrist at and slightly proximal to the volar wrist flexion creases when the patient flexes the fingers during repetitive flexion and extension of the fingers. The authors did not address this component of their physical examination in their paper; in fact, I have never seen the observation of this clinical finding mentioned in the literature.
The ultimate issue regarding this discussion, particularly in the patient performing repetitive work, is recurrence. The authors’ references to Wheatley and Kaul as well as Blaum et al. are noteworthy. I began seeing "cumulative trauma" patients with failed CTR. These patients had undergone carpal tunnel release months or years previously, and had been released to return to work by their operating physician. Most operative notes in these patients showed tourniquet times of approximately ten minutes. Although their symptoms of median compressive neuropathy had been primarily relieved, they were still complaining of pain and the inability to work. Workers’ compensation benefits were being requested.
It is my observation that patients upon whom I have operated for previously failed CTR were ultimately relieved of their pain. After appropriate strengthening, aerobic conditioning, and weight loss, these patients also returned to work, generally without restriction. To conclude that flexor tenosynovectomy should never be performed would have been a disservice to these patients, and to suggest this as the primary conclusion of Shum’s article is inappropriate.
I wish to thank my senior resident, Joseph Cohn, M.D., for urging me to write this response.
Letters to the Editor: ![[Read Letter to the Editor]](/icons/misc/sectionDOWN.gif){kind=icon}
