Raynaud's phenomenon

In a previous study the prevalence of Raynaud's phenomenon (RP) in patients with idiopathic carpal tunnel syndrome (CTS) was found to be 60% which is much higher than that in the general population, We undertook a further study of the same cohort of patients have both CTS and RP and who had an open release of the carpal tunnel, to observe the effects of the operation on RP We observed whether the symptoms of RP improved, and repeated the cold provocation tests to see if the arterial pulse which was decreased before operation would recover We rated the outcome as good when the patients showed both an improvement of the symptoms of RP and a normal pulse amplitude after exposure to cold, fair when the pulse amplitude recovered to more than two-thirds of that before exposure, and poor when cold hypersensitivity was persistent or showed the same degree of decreased pulse amplitude as observed before operation. Of the 18 patients with both conditions, ten (56 % ) had good and four (22 % ) fair results, with a mean recovery time of 4.2 months (6 weeks to 1 year) after operation.

If the vasospasm seen in RP is an expression of vasomotor irritation in the carpal tunnel, these findings suggest that local compression of vasomotor fibres in the carpal tunnel can also be relieved by the release of this structure. Careful consideration, however, is still required in treating patients with both conditions since in some cases. RP may be superimposed or it may have other origins.

J Bone Joint Surg [Br] 2000;82-B:818-9.

Received I February 2000, Accepted 9 March 2000

In 1999 we observed that the prevalence of Raynaud's phenomenon (RP) in patients with idiopathic carpal tunnel syndrome (CTS) was 60%, much greater than would be expected in the general population.l As a follow-up study, we tried to establish whether decompression of the carpal tunnel would improve the symptoms of RP as well as those of CTS in patients with both conditions.

Patients and Methods

We studied 18 patients diagnosed as having both idiopathic CTS and RP They all had symptoms of CTS, such as paraesthesia, numbness and nocturnal pain in the fingers, more than one of the clinical signs of CTS such as the Tinel or Phalen, atrophy of the thenar muscles, and abnormal electromyographic (EMG) readings such as delayed nerve conduction distal to the wrist. The conduction time on the EMG was considered to be prolonged if the terminal latency of the motor impulse exceeded 4.5 ms or if the sensory antidromic latency was greater than 3.5 ms.2 All underwent surgery to release the volar carpal ligament and have been followed for more than a year.

This is the same cohort of patients which was studied in our previous report.l The mean duration of symptoms of CTS was 5.7 years (2 months to 20 years). The condition was bilateral in 11 patients and unilateral in seven, but RP was present in both hands of all patients.

We performed carpal tunnel release in the affected hands of these patients, using the same open surgical procedure with a midpalm curved longitudinal skin incision, under local anaesthesia and pneumatic tourniquet. The palmar sensory branch of the median nerve was preserved. There were no complications such as wound infection. A cold provocation test for RP using photoplethysmography1,3 was performed at six weeks, three months, six months, and one year after the operation. We observed whether the symptoms of RP, particularly the hypersensitivity to cold exposure, improved, and we repeated cold-provocation tests to see if the amplitude of the arterial pulse which was decreased before operation would recover.

We rated the outcome as good in patients showing both an improvement of the symptoms of RP and a normal pulse amplitude after cold exposure, and fair in those with a considerably recovered pulse amplitude, i.e. more than twothirds of that before exposure. A result was considered poor when the patient persistently complained of cold hypersensitivity or showed the same degree of decreased pulse amplitude as observed before operation. The final grading was given after an interval of at least a year. We defined the recovery time as the interval between the operation and the day when the patient first described his condition as better than fair.

Results

Of the 18 patients, ten had good, four fair, and four poor results. Ten patients (56%) were therefore regarded as having recovered from RP and 14 (78%) improved at least in the cold-provocation test. The mean time to recovery was 4.2 months (6 weeks to 1 year). All 11 patients with bilateral symptoms of CTS showed improvement of RP in both hands but four patients out of seven with unilateral involvement did not show recovery. The other three patients with unilateral CTS differed in regard to their RP; one showed recovery in the operated hand only and the other two had improvement in both hands. The duration of symptoms of CTS showed no significant correlation with the recovery time of RP.

Discussion

The pathogenesis of RP remains unclear. The local or systemic sympathetic nervous system, however, has been considered to play a significant role in the constriction of the digital arteries.4,5 The mechanism of RP in patients with CTS is also uncertain. Vasomotor sympathetic fibres to the fingers are mainly conducted through the median nerve,6 and therefore the vasospasm seen in RP may be an expression of irritation of vasomotor fibres. This hypothesis is relevant to the pathogenesis of RP In this study, 56% of patients with both conditions showed recovery from RP and 78% improved to some degree.

These results lend some support to the hypothesis that RP may be caused by compression of the median nerve. The surgical response of the patients who showed unilateral involvement of the CTS and RP in both hands fails to confirm this. Some patients with RP have improvement in both hands, although only one hand was operated on, and some showed no recovery at all. These findings suggest that constitutional or systemic factors are also important.

If CTS and RP are not causally related, i.e., when the onset of RP precedes that of CTS, or RP occurs incidentally with CTS, the results of carpal tunnel release are quite different from those in this study. We attempted to distinguish beween the onset of each condition in order to rule out cases of superimposition, but in practice the patients were not able to separate the date of onset of the two conditions.

We have been encouraged that, in contrast to the doublecrush syndrome in which carpal tunnel release may have less satisfactory results,7 we can expect a reasonable outcome in patients suffering from both conditions (CTS and RP) after simple decompressions of the carpal tunnel.

Our findings suggest that local compression of vasomotor fibres in the carpal tunnel can also be relieved by release of the carpal tunnel. Careful consideration, however, is still required in treating patients with both conditions since in some cases, RP may be superimposed or it may be caused by other systemic conditions.

The authors wish to acknowledge the financial support of the Korea Research Foundation made in the programme year of 1998.

No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.

References

1. Chung MS, Gong HS, Baek GH. Prevalence of Raynaud's phenomenon in patients with idiopathic carpal tunnel syndrome. J Bone Joint Surg (BrJ 1999;81-B:1017-9.

2. Szabo RM, Gelberman RH, Dimick MP. Sensibility testing in patients with carpal tunnel syndrome. J Bone Joint Surg (AmJ 1984;66-A:60-4.

3. Tordoir JH, Haeck LB, Winterkamp H, Dekkers W. Multifinger photoplethysmography and digital blood pressure measurement in patients with Raynaud's phenomenon of the hand. J Vasc Surg 1986;3:456-61.

4.Harada N, Kondo H, Kimura K. Assessment of autonomic nervous function in patient with vibration syndrome using heart rate variation and plasma cyclic nucleotides. Br J Ind Med 1990;47:263-8.

5. Keenan EJ, Porter JM. Alpha-adrenergic receptors in platelets from patients with Raynaud's syndrome. Surgery 1983;94:204-9.

6. Campero M, Verdugo RJ, Ochoa JL. Vasomotor innervation of the skin of the hand: a contribution to the study of human anatomy. JAnat 1993;182:361-8.

7. Idler RS. Persistence of symptoms after surgical release of compressive neuropathies and subsequent management. Orthop Clin North Am 1996;27:409-16.

M. S. Chung, H. S. Gong, G. H. Baek

From the National University College of Medicine, Seoul, Korea

M. S. Chung, MD, Professor and Chairman

H. S. Gong, MD, Orthopaedic Resident

G. H. Baek, MD, Assistant Professor

Department of Orthopaedic Surgery, Seoul National University College of Medicine, 28 Yongon-Dong, Chongro-Gu, Seoul 110-744, Korea.

Correspondence should be sent to Professor G. H. Back.

Copyright British Editorial Society of Bone & Joint Surgery Aug 2000
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