Trigger thumb

Sir,

We read with interest the article by Dunsmuir and Sherlock1 in the July issue entitled "The outcome of treatment of trigger thumb in children'. The subject of this article is important as surgery, especially in young children, should be avoided unless absolutely necessary.

We understand that a high proportion of trigger thumbs present with a fixed flexion posture, but the exact number in the study was not given. What proportion, if any, presented with the symptom of triggering, and what proportion had a fixed flexion deformity at presentation?

We note that the patients were not randomly allocated to either treatment or observation groups. Could it be that the 53 children in the deferred group had a less degree of triggering, so that the option of surgery was not impressed on the parents as much as it was when a child had a significant trigger thumb with fixed flexion on presentation?

We are not aware of any recognised classification of the severity of triggering, even although this condition varies in its severity from patient to patient. Would it not have been possible to group patients according to whether the deformity was correctable by gentle manipulation or not?

Five of the six infants presenting at less than six months of age ultimately required surgery and there was a higher spontaneous rate of recovery in infants over 12 months (57.9%). Should we therefore not be treating these 'congenital' (

Until a prospective, randomised study is performed it is difficult to draw a conclusion that can be applied to our daily practice.

N. EMMS, FRCS

S. SCOTT, FRCS

Aintree University Hospital, Liverpool, UK.

1. Dunsmuir RA, Sherlock DA. The outcome of treatment of trigger thumb in children. J Bone Joint Surg [Br] 2000;82-B:736-8.

Authors' reply:

Sir

We thank the correspondents for their interest in our paper. Our paper is a retrospective review of practice in our hospital. The data obtained in case notes frequently varies in its completeness. We are therefore unable to comment on the exact proportion of children with fixed flexion deformities at presentation or with deformities correctable by manipulation. Most, however, had fixed flexion with only a small proportion having true triggering.

Nor can we comment specifically about the severity of the condition in our deferred group of children. We have no reason to believe that the spread of severity of the condition varied between the deferred and operated groups. There was, however, a higher proportion of children with bilateral trigger thumbs in the operated group. This may be indirect evidence of parents being more insistent on surgical treatment when both hands are affected.

Five of the six infants first seen at less than six months of age ultimately required surgery. We believe that only one of these was truly congenital, presenting at one month. The remainder we believe to have acquired trigger thumbs. Despite the high operative rate in this subgroup, we still feel that an aggressive operative policy in these children is not warranted. We have no evidence of postoperative fixed flexion deformities in our study group, even in those infants presenting after three years of age. With this in mind we feel that a conservative approach should continue to be the norm with these younger children, to allow the maximum time for spontaneous resolution of the problem.

We have been unable to find any evidence to support the use of manipulation to grade this condition. We feel that any anecdotal evidence for the use of manipulation to treat trigger thumbs merely reflects the higher than anticipated natural spontaneous rate of resolution of this condition.

We accept that our study displays some of the problems associated with retrospective reviews. We also fully endorse the need for properly randomised, controlled trials.

We do, however, feel that our study is important since it questions some of the commonly held beliefs.

D. A. SHERLOCK, DPhil, FRCS

R. A. DUNSMUIR, FRCS Orth

Royal Hospital for Sick Children

Glasgow, UK.

Copyright British Editorial Society of Bone & Joint Surgery Mar 2001
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