Linburg syndrome - Canadian Journal of Surgery

Docket: 1-5528
Initial: JN
Customer: CJS August/98
15528 Aug 98 CJS /Page 306
Original article
Article original
LINBURG SYNDROME
William R.J. Rennie, MD; Hellmuth Muller, MD
OBJECTIVE: To review the causes and demographics of Linburg syndrome.
DESIGN: An illustrative case report and a demographic study.
SETTING: Adult and pediatric orthopedic clinics at the Health Sciences Centre in Winnipeg.
PATIENTS: One patient with Linburg syndrome and 200 patients and relatives presenting to adult and pediatric orthopedic clinics with conditions not involving their hands, wrists or forearms.
OUTCOME MEASURES: The presence of the intertendinous anomaly and of carpal tunnel syndrome.
RESULTS: Tendinous connection(s) between flexor pollicis longus and flexor digitorum profundus muscles
were found in 20% of the study population. The anomaly was found in all age groups. No association was
found between Linburg syndrome and the presence of carpal tunnel syndrome or previous injury to the
hand or forearm.
CONCLUSION: Tendinous connection between flexor pollicis longus and flexor digitorum profundus muscles is a common anomaly that rarely causes clinical symptoms.
OBJECTIF : Revoir les causes et les aspects démographiques du syndrome de Linburg.
CONCEPTION : Étude de cas illustrée et étude démographique.
CONTEXTE : Cliniques d’orthopédie pour adultes et enfants au Centre des sciences de la santé de Winnipeg.
PATIENTS : Un patient atteint du syndrome de Linburg et 200 patients et membres de leur famille qui se
sont présentés à des cliniques d’orthopédie pour adultes et enfants avec des problèmes qui ne touchaient
pas les mains, les poignets ou les avant-bras.
MESURES DE RÉSULTATS : La présence de l’anomalie intertendineuse et du syndrome du canal carpien.
RÉSULTATS : On a constaté la présence de ponts tendineux entre le muscle long fléchisseur propre du pouce
et le muscle fléchisseur commun profond des doigts chez 20 % des sujets étudiés. On a trouvé l’anomalie
dans tous les groupes d’âge. On n’a établi aucun lien entre le syndrome de Linburg et la présence du syndrome du canal carpien ou une blessure antérieure à la main ou à l’avant-bras.
CONCLUSION : La présence de ponts tendineux entre le muscle long fléchisseur propre du pouce et le muscle
fléchisseur commun profond des doigts est une anomalie fréquente qui cause rarement des symptômes cliniques.
A
nomalous tendinous connections between flexor pollicis
longus and flexor digitorum
profundus muscles were described in
the clinical literature in 1979 by Linburg and Comstock,1 and subsequently the condition was titled Linburg syndrome. Early references in
the anatomic literature2–4 and subsequently in the clinical literature5–7
failed to note any clinical significance.
A more recent notation by Lombardi,
Wood and Linscheid8 suggested that
tenosynovial adhesions might be the
cause in a significant number of cases.
Similar anomalies have been described
in primates suggesting a similar embryologic basis. As noted by Linburg
and Comstock,1 the anomaly was
thought to be of clinical significance
as a cause of chronic forearm pain and
possibly to be associated with carpal
tunnel syndrome. We present an illustrative case and the findings of a demographic study to elucidate the features of Linburg syndrome.
ILLUSTRATIVE CASE REPORT
A 31-year-old right-hand dominant Inuit woman presented in March
1995 complaining of activity-related
distal left forearm pain when sewing
From the Section of Orthopedic Surgery, Health Sciences Centre, University of Manitoba, Winnipeg, Man.
Accepted for publication Sept. 19, 1997
Correspondence to: Dr. William Rennie, Section of Orthopedic Surgery, Health Sciences Centre (General), 700 William Ave., Winnipeg MB R3E 0Z3
© 1998 Canadian Medical Association (text and abstract/résumé)
306
JCC, Vol. 41, No 4, août 1998
Docket: 1-5528
Initial: JN
Customer: CJS August/98
15528 Aug 98 CJS /Page 307
LINBURG SYNDROME
and cooking and a lack of independent flexion in the left thumb and index finger. The latter was verified on
physical examination and had apparently been present since birth. Surgical exploration was carried out in August 1995, demonstrating a tendinous
connection between flexor pollicis
longus and flexor digitorum profundus
muscles to the index finger (Fig. 1).
This was simply divided, and independent flexion of thumb and index finger
was restored (Figs. 2 and 3). Followup revealed full pain-free function.
DEMOGRAPHIC STUDY
All patients and relatives attending
the adult and pediatric orthopedic
clinics at the Health Sciences Centre
in Winnipeg were studied except for
those who refused a brief history and
physical examination pertaining to the
syndrome. In addition, patients were
excluded if they had acute conditions
involving their hands, wrists and forearms. For example, in a patient returning for follow-up after hand or wrist
surgery the interconnection might
FIG. 1. An intraoperative view showing the flexor pollicis longus muscle (the arrow at left), the index
flexor digitorum profundus (arrow at right) and the tendinous connection (lower of the 2 tendons
spanning the tongue blade).
FIG. 2. Independent thumb flexion postoperatively.
have developed as a result of the
surgery so these patients were excluded. There were 200 subjects.
Each subject was asked to independently flex the interphalangeal joint of
each thumb and simultaneous flexion
of one or more distal interphalangeal
joints (when present) was noted. As
well, enquiry was made of a history of
previous injury or pain in the hand(s)
or forearm(s). When the anomaly was
discovered, virtually all subjects were
completely unaware of its existence.
Of the 200 people studied, 90 were
male and 110 were female. Nineteen
percent of males and 21% of females
demonstrated the anomaly. It was
found in 17 right hands, 9 left hands
and was bilateral in 14 people. Or, to
put it another way, Linburg syndrome
was present in 20% of the people
(40/200) but in only 13.5% of the
hands examined (54/400). The age
distribution of those studied and the
incidence of the anomaly related to
age is shown in Table I.
Multiple digits were involved in 6
patients. In 4 of them, the index and
long fingers were connected to the
thumb flexor bilaterally. One patient
had unilateral index and long finger
connection and the final patient had a
tendon connection between the
thumb and long finger only.
All patients were questioned
regarding the presence of carpal tunnel syndrome (i.e., pain, paresthesias,
FIG. 3. Independent function of the index flexor digitorum profundus muscle postoperatively.
CJS, Vol. 41, No. 4, August 1998
307
Docket: 1-5528
Initial: JN
Customer: CJS August/98
15528 Aug 98 CJS /Page 308
RENNIE AND MULLER
night-time symptoms, clumsiness),
but no association was found between
the 2 conditions, contrary to the suggestion by Linburg and Comstock.1
No association was found between
the presence of tendon interconnections and previous injury to the hand
or forearm.
DISCUSSION
Unlike the collected surgical series
of Lombardi, Wood and Linschied,7
and despite the presence of an antomic
anomaly, the individuals in our demographic series had no symptoms and,
indeed, many were unaware of the
anomalous movement. This would
suggest that, although possible, the
anomaly itself is an uncommon cause
of forearm pain or of carpal tunnel syndrome. It would seem likely that some
other, perhaps activity-related event(s),
must trigger the clinical symptoms. Indeed, in some instances, an adhesive
tenosynovitis may cause the syndrome.
We did not, however, find evidence of
that mechanism in the subjects we
studied.
The presence of this anomaly in all
age groups studied is, in our opinion,
more in keeping with a congenital lesion than an aquired lesion.
Interconnecting tendon slips from
the flexor pollicis longus to multiple
digits have been described1 and presumably arise for similar embryologic
reasons to the more common interconnection of the index finger.
CONCLUSIONS
Anomalous tendon interconnections between flexor pollicis longus
and flexor digitorum profundus muscles (Linburg syndrome) is a common
Table I
Tendinous Connections Related to Age in 200 Patients Studied
Total subjects in
group
No. with intertendinous
connections
0–10
24
4
11–20
37
8
21–30
37
13
31–40
52
6
41–50
34
5
51–60
11
2
61–70
1
1
71–80
4
1
Total
200
40
Age group, yr
308
JCC, Vol. 41, No 4, août 1998
anatomic anomaly. Most people are
unaware of its presence. There appears
to be no association between the
anomaly and carpal tunnel syndrome
or injury. Surgical treatment, although rarely necessary, is simple and
effective.
References
1. Linburg RM, Comstock BE. Anomalous tendon slips from the flexor pollicis longus to the flexor digitorum profundus. J Hand Surg 1979;4:79-83.
2. LeDouble AF. Traité des variations du
système musculaire de l’homme. Vol. 2,
Paris: Schleicher; 1987. p. 115-20.
3. Testut L. Les anomalies musculaires
chez l’homme expliqués pas l’anatomies
comparée. Leur importance en anthropologie. Paris: G. Masson; 1884.
4. Wood J. On some varieties in human
myology. R Soc Proc 1867;15:229-44.
5. Spinner M. The importance of muscle
variations as a factor in the deformity
of Volkmann’s contracture. Bull Hosp
Joint Dis 1973;34(1):48-53.
6. Dykes JAB. The accessory tendon of
the flexor pollicis longus muscle. Anat
Rec 1944;90:83-7.
7. Kaplan EB. Correction of a disabling
contracture of the thumb. Bull Hosp
Joint Dis 1942;3:51-4.
8. Lombardi RM, Wood MB, Linscheid
RL. Symptomatic restrictive thumb–
index flexor tenosynovitis: incidence of
musculotendinous anomalies and results of treatment. J Hand Surg 1988;
13A:325-8.