The anatomy and treatment of camptodactyly of the small finger Having observed an anomalous

insertion of the lumbrical

for correction of camptodactyly

of the small finger, we have concluded that the loss of normal

lumbrical

muscle in 74 consecutive

operations

action is the principal cause of the intrinsic minus deformity seen in this condition.

Other anatomic

abnormalities

observed in this series of patients are those of the superficial

tendon in 47%, the x-ray appearance a fixed flexion contracture flexion contracture to this deformity,

of the proximal interphalangeal

of the PIP joint in 66%. Fifty-seven

(PIP) joint in 15%) and

percent of our patients had PIP

of more than 45 degrees. To determine the contribution we analyzed

of these anomalies

a series of 53 patients who had been followed up for at least 1

year. The study revealed that these conditions are interdependent effect on the final operative results. Treatment the ring or little finger to the extensor

mechanism

procedures

situation.

as dictated by the individual

and that each had an adverse

included a transfer of the superficial tendon of of the little finger in all cases and other Overall, the joint contracture

was reduced

from 49 degrees to 25 degrees, but only 33% of the patients regained full flexion of the small

finger. (J

HAND SURC 1992;17A:35-44.)

Robert M. McFarlane, MD, FRCS(C), Dale A. Classen, MD, London, Arthur M. Porte, MD, FRCS(C), Hamilton, Ontario, Canada, and Jeanette S. Botz, HNC, London, Ontario, Canada

I

n each of 74 consecutive operations for camptodactyly we found that the lumbrical muscle (lumbrical IV) to the small finger had an anomalous insertion. Thus we still believe that the intrinsic minus deformity is due mainly to the absence of normal lumbrical action.’ Many surgeons disagree that the lumbrical insertion is always abnormal and have suggested other factors that might cause the deformity.‘-4 We too have observed other anatomic abnormalities at operation but they were not seen consistently. In an attempt to further support our view that an abnormal lumbrical insertion is the prime cause of camptodactyly, we have considered the contribution that other anatomic abnormalities make to the deformity. We analyzed a series of 53 patients for whom

From the Division of Plastic Surgery, The University of Western Ontario, London. Ontario. and the Division of Orthopaedic Surgery. McMaster University. Hamilton, Ontario. Canada. Received for publication May 10, 1991.

Sept.

Il.

1990: accepted

in revised form

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. Reprint requests: Robert M. McFarlane, MD. FRCS(C), St. Joseph’s Health Centre, 268 Grosvenor St.. London, Ontario. Canada N6A 2X3. 3/l/31210

Ontario, Canada,

preoperative, operative, and postoperative data were complete, with a minimum follow-up of 1 year, with respect to the cause and severity of the deformity and the results of treatment. The data are summarized in Table I.

Preoperative and operative observations Severity of contracture and fixation of the proximal interphalangeal joint. The average proximal interphalangeal (PIP) joint contracture was 49 degrees. In two thirds of the patients the contracture was fixed, and full passive extension was not possible. Joint fixation was tested with the wrist joint and the metacarpophalangeal (MP) joint separately flexed and extended. The contracture was not altered by the position of either joint. When passive extension was present at the PIP joint, supporting the MP joint in flexion usually allowed active PIP joint extension but wrist flexion did not. In cases of severe contracture, the skin was foreshortened and a fascial band was palpable on the ulnar side of the proximal segment of the small finger. At operation, incision of the skin and fascia did not alter a fixed PIP contracture. Opening the flexor tendon sheath at the PIP joint permitted some extension. Division of the superficial tendon of the small finger (superficialis V) did not alter the contracture, but sectioning of the accessory collateral ligament or palmar plates permitted release. THE JOURNAL

OF HAND

SURGERY

35

36

The Journal of HAND SURGERY

McFarlane et al.

Fig. 1. This boy was seen at 2 years of age with bilateral camptodactyly of 45 degrees in the right little finger and 50 degrees in the left. The contractures were fixed and he had no superficialis action. The left hand was operated on at age 2 and the right hand at age 4. The findings at operation were the same in both hands. A, Preoperative x-ray film of the left little finger showed dorsal flattening of the head of the proximal phalanx. B, Postoperative film taken 5 years later showed persistence of the dorsal flattening. C, The lumbrical muscle attached completely to the capsule of the MP joints and palmar interosseous IV passed to the ring finger. The instrument on the left is under lumbrical IV, and the instrument on the right is under palmar interosseous IV. Table I. Camptodactyly:

53 operations

on the small

finger

Average age - 15years Sex - 58% female Hand - 66% right Preoperative findings PIP joint contracture Fixed contracture Superficialis V independent Normal x-ray Operative findings Lumbrical insertion Capsule MP joint Superficialis V Ring extensor Absent Results of treatment at 1 year Improve contracture Perfect Improved Worse Postoperative Contracture < 15” Flexion to distal crease of palm Full flexion

49” 66% 36% 85%

78% 9% 9% 4% 49”-25” 22% 61% 11% 47% 1.8 cm 33%

Superficialis V Independent Adherent

53% 13% 34%

Vol. 17A, No. 1 January 1992

Camptodactyly of small finger

37

Fig. 1 (Cont’d). The decussation and insertion of superficialis V were normal, but the tendon ceased to exist proximal to the Al pulley. The entire tendon was removed as shown on the skin. E, The range of flexion is shown 3 years later. The tip of the finger missed the distal crease of the palm by 3 cm. The tension applied to the tendon transfer was excessive.

The status of superficialis V. The superficialis V tendon was tested preoperatively to determine whether it was independent or adherent to superficialis IV or was ab sent. As shown in Table I, only 36% of these tendon! s were independent. We could not positively determim : the absence of the superficial tendon in the rest

of these patients, so the remaining 64% were conside :red )me to be adherent to superficialis IV. At operation SC adherent tendons were attached to superficialis IV by delicate fascia, and the tendons were easily separai ted. Thus 53% were included in the independent group because they were deemed suitable for use in tendon trl Ins-

38

The Journal ot HAND SURGERY

McFarlane et al.

Fig. 2. This 26-year-old white woman had rheumatoid arthritis since age 10. She first noticed flexion of the left small finger when she was in her late teens. The deformity became progressively worse, and in the last year it had interfered with her work as a typist. A course of splinting for 3 months did not change the contracture. At operation the lumbrical muscle was attached to the side of the MP joint and some muscle fibers passed to the extensor mechanism. Superficialis V was adherent to superficialis IV by delicate fibers, which were easily separated to make it independent. For tendon transfer, it was passed deep to the transverse metacarpal ligament and sutured to the extensor mechanism. The PIP joint was not released but was held in 35 degrees of flexion with a Kirschner wire. A, Preoperatively the patient had 85 degrees of PIP joint contracture with passive extension to 30 degrees and full flexion. B, The preoperative x-ray film showed extreme palmar subluxation and axial rotation of the middle phalanx.

fer. The adherent tendons were attached to superficialis IV by tendon fibers. Absence of the supetficialis V was observed at operation in 34% of the patients. The decussation and insertion were present, but the tendon ceased to exist either within the tendon sheath or just proximal to it, blending into the surrounding fascia (Fig. 1, D).

X-ray appearance of the PIP joint. All patients had at least one x-ray examination.

Because

of the technical

difficulties of obtaining a true lateral x-ray picture, however, only 49 lateral views were suitable for analysis and only 17 postoperative views were available for comparison. Dorsal flattening of the head of the proximal phalanx

Vol. 17A, No. 1 January 1992

Camptodactyly

of small jinger

39

Fig. 2 (Cont’d). C, D, and E, After 1 year the patient had 25 degrees of contracture and was 2.5 cm short of full flexion. The x-ray film showed correction of the palmar subluxation. The patient is very well pleased with this result.

(Fig. 1, A) was seen in nine hands of eight patients. Five of these patients were less than 5 years of age, and three were teenagers. All had severe and fixed PIP joint contracture. Superficialis V was absent in five of six infant hands. Flexion of the head and palmar neck depression of the proximal phalanx appeared to be present when the joint was flexed, but this was less apparent or disappeared when the joint was extended. Palmar subluxation of the base of the middle phalanx was suggested with severe PIP contracture (Fig. 2, B). With improvement of the contracture, the congruity of the joint was normal (Fig. 2, E). Dorsal displacement and a groove in the dorsal articular surface of the middle phalanx were see often on preoperative x-ray films but disappeared when the joint was more extended. In older patients, however, this deformity can exist and prevent correction of the contracture.

Anomalous insertions of lumbrical IV and palmar interosseous IV. As listed in Table I, the lumbrical muscle was absent in 4% (two patients) and the insertion was abnormal in the remainder. The most frequent abnormal insertion found at operation was that of muscle fibers into the soft tissue on the side of the MP joint, either completely or with some of the muscle fibers also

attached to the free margin of the extensor mechanism (Figs. 1, C and 3, A). Whether the insertion onto the MP joint was complete or incomplete, traction on the belly of the muscle did not extend the PIP joint. The fibers could be removed from the capsule only by sharp dissection. Less commonly lumbrical IV inserted onto superficialis V (Fig. 3, B) or onto the extensor mechanism of the ring finger (Fig. 3, C). The ring finger was not opened to confirm this insertion, but traction on the lumbrical muscle always extended the PIP joint of the ring finger. As reported previously,’ palmar interosseous muscle IV, which normally has a bony insertion into the radial side of the proximal phalanx of the little finger,’ was observed to pass to the ring finger (Fig. 1, C). It is difficult to expose this muscle at operation without dividing the transverse metacarpal ligament, opening the interosseous space, and differentiating palmar interosseous IV from dorsal interosseous IV (which passes to the ulnar side of the ring finger). Thus we cannot give precise figures on the frequency of this anomaly.

Surgical treatment No patient with a contracture of less than 30 degrees was operated on. Preoperative splinting was not necessary if the patient had passive extension. but it could

40

McFarlane et al.

The Journal of HAND SURGERY

Fig. 3. A, The lumbrical muscle attached to both the MP joint capsule and the extensor mechanism. B, The lumbrical muscle attached onto the palmar surface of superficialis V proximal to the Al pulley. C, The lumbrical muscle passed to the ulnar side of the ring finger, presumably to the extensor mechanism.

lessen the contracture and perhaps reduce the need for a soft tissue release at the PIP joint in patients with no passive extension. The operation has varied slightly from that described previously.’ A midline longitudinal incision from the distal to the proximal finger crease is recommended because it permits good exposure of the flexor mechanism and can be closed with one or two Z-plasties to overcome skin and fascial shortage. A zigzag incision can be used in the palm because there is no skin shortage. The incision should extend proximally to the transverse carpal ligament to expose all of the lumbrical muscle and to permit examination of connections between superficialis V and IV. The anomalous insertion of the lumbrical muscle will not be apparent unless the muscle is released from its fascial covering and the muscle fibers are traced to their

attachment. The insertion of palmar interosseous IV was also examined. Once the status of the intrinsic muscles had been determined, the flexor tendon sheath was opened as a flap that included the A3 pulley. Superficialis V was divided just proximal to the vincula longa and withdrawn into the palm. Traction on the tendon was not enough to determine its independence from superficialis IV It had to be dissected proximally until both tendons were seen to pass independently into the carpal tunnel. It was during this dissection that some fascial and synovial tissues that held the tendons together were divided. If the tendon was firmly adherent to superficialis IV, it was divided and discarded. When superficialis V was independent, it was passed dorsal to the transverse metacarpal ligament and woven through two stab wounds in the extensor mechanism.

Vol. 17A, No. 1 January

Camptodactyly of small jnger

1992

Table II. Superficialis

V at operation Independent

independent

group had lower

preoperative

Table III. Preoperative

and postoperative

contractwes

45” Fixed contracture Improved contracture* Postoperative contracture < 15” *The

41

preoperative and postoperative contraclures were less than in

the >45-degree

group.

fixed PIP joint contracture

Contracture >45” Superficialis V independent at OP Improved contracture* Postoperative contracture < 15

Present (n = 35)

p value

Absent (n = 18)

69% 40% 52”-30” 36%

0.025 0.025 0.001 NS

33% 77% 44”- 15” 65%

*The preoperative contractures were not different. but the postoperative contractwe was significantly less in the absent group.

It was sutured under maximum tension with the wrist and the MP joint in neutral position and the PIP joint extended as much as possible. If there was passive PIP extension and traction on the extensor mechanism extended the PIP joint, the Zancolli lasso procedure7 to the A2 pulley was used as suggested by Millroy and Millender (personal communication). When superficialis IV was used for tendon transfer, one slip was attached to the extensor mechanism as described and the other slip was attached to the A2 pulley. The slip to the extensor mechanism was attached first, and then the second slip was attached under the same tension. We used this technique because most patients who had a transfer into the extensor mechanism maintained PIP joint correction but MP joint hyperextension recurred (Fig. 2, C). A soft tissue release at the PIP joint was performed if the residual contracture was more than 30 degrees. This occurred in 26% of the operations. This group had

an average preoperative contracture of 57 degrees and a postoperative contracture of 33 degrees. The return of flexion was the same in this group as in those without the joint release. A Kirschner wire was inserted across the PIP joint in maximum extension and the hand was immobilized in flexion at the wrist and the MP joint. The Kirschner wire was removed at 3 weeks and the hand was immobilized in the same position for 2 more weeks. An extension splint was worn at night for 3 to 6 months and for decreasing periods during the day. Flexion was always slow to recover at both interphalangeal joints. Therapy was directed at recovery of flexion as well as maintenance of extension.

Results of treatment The overall results are shown in Table I. Few patients gained full extension, but almost one half had less than 15 degrees of residual flexion deformity. This amount of PIP flexion is not a functional or cosmetic deficit,

42

McFarlane et al.

so it is a reasonable outcome standard. Tables II, 111, and IV show that the results were better when the superficialis tendon was independent, the preoperative contracture was less than 45 degrees, and the PIP joint was not fixed. In this study seven patients had a superficialis V that was adherent to superficialis IV. Six of them had severe and fixed contractures. The average postoperative flexion in this group was 41 degrees. Although the results were worse than in the groups listed in Table II, the numbers were too small for statistical analysis. In each of these patients superficialis V was used for the tendon transfer. We believe that the poor results in this group were due to the inappropriate use of an adherent superficialis V. Return of flexion was slow for all patients (Figs. 1 and 2). It was never obtained within 6 months, and only 33% of the patients regained full flexion at 1 year. The average residual lag was 1.8 cm from the distal crease of the palm. This residual deformity may have been due to excess tension in the tendon transfer, but the dissection of the lumbrical muscle, the opening of the tendon sheath and removal of superficialis V, and finally the tendon transfer created scar tissue that could block flexion. Four patients were operated on again because the contracture at the PIP joint was not improved or was worse. They lacked active flexion at both interphalangeal joints. In each case the PIP joint was fixed by adhesions arising from the superficialis slips, the profundus tendon was adherent along the entire length of the fibrous tendon sheath, and the superficialis tendon transfer was adherent throughout its course to the extensor mechanism. Only slight improvement in flexion and extension was gained by a second operation.

Discussion We have confined our study of camptodactyly to its most common site of presentation, the small finger. The true incidence is not known. The deformity ranges from slight contracture, requiring no treatment, to severe and fixed PIP joint contracture. Camptodactyly should be considered a diagnostic rather than a descriptive term. Geneticists and others use the term loosely to describe any flexion contracture of a digit (including the thumbs and toes) and believe that the deformity is caused by any factor capable of limiting limb movement in utero.‘, 9 We prefer that use of the term be restricted to the congenital intrinsic minus deformity of the small finger and occasionally the ring and middle fingers.

The Journal of HAND SURGERY

The only consistent anatomic abnormality that we observed was an abnormal insertion of lumbrical IV. This anomaly is not readily apparent and will be seen only when the lumbrical insertion is carefully examined. A normal insertion was reported in 60% of anatomic specimens by Mehta and Gardiner,‘” 66% by Eyler and Markee,” and 72% by Basu and Hazary. I2 These authors reported absence of the muscle in 0% to 5% and an abnormal insertion in 17% to 35% of their patients. Their observations were similar to those listed in Table I, except that insertion of the muscle onto the superficialis tendon of the small finger was not seen by any of them. Anatomic variations of superficialis V have been described in the forearm, the hand, and the small finger. Brand et al. I3described the common origin and digastric muscle bellies of the superficialis tendons to the index and small fingers. They suggested that neither tendon should be used for tendon transfer without including the other. KaplanI noted the origin of superficialis V from the ulna as well as adherence to adjacent tendons. Lillmars and Bush” described the muscle origin in the palm. Courtemanche’6 reported insertion of lumbrical IV into superficialis V in camptodactyly. This anomaly has not been reported in patients without camptodactyly. Fumas” observed the absence of superficialis V in 5% of 117 dissections at the wrist. Chowdhary” described a single dissection in which the decussation and insertion of superficialis V were normal; but proximally the tendon disappeared into the interosseous fascia. In 4 of 20 dissections Shrewsbury and Kuczynski” noted a normal insertion but absence of the tendon proximal to the fibrous tendon sheath. In 40 anatomic dissections Austin et al.*’ did not find a tendon missing. Superficialis V was absent at operation in 34% of our patients. Absence of the tendon was associated with a more severe deformity, but this could not be the cause of the deformity because it was not seen in all patients. The status of superficialis V was analyzed in relation to the severity of contracture and the results of treatment as shown in Table II. When the tendon was independent, the contracture was more likely to be less than 45 degrees and not fixed, and the result of treatment was better. X-ray changes at the PIP joint are a matter of inand various changes have been reterpretation, pofied.2. 3. 21-23 Dorsal flattening or tapering of the head of the proximal phalanx was the only x-ray abnormality that did not disappear with correction of the contracture in our patients. It was associated with fixed flexion and

Vol. 17A. No. I January 1992

severe

contracture

ficialis

V. Three

Camptodactyly

and usually teenagers

with absence

with

dorsal

of super-

flattening

did

Five children less than 5 years of age did not, but we believe the poor results were due to the technical problems of tendon transfer in infants. Dorsal displacement with a groove in the articular surface at the base of the middle phalanx is considered by Buck-Gramckoz2 to be a contraindication to operation because the joint incongruity prevents extension. This deformity was commonly seen on the preoperative lateral x-ray film, but we were unable to extend the joint because of it in only two patients, both of whom experienced some improvement of the contracture. Even if x-ray changes do occur, we do not believe that they are a contraindication to operation. They may be a factor in preventing full correction, however. One purpose of this study was to determine whether a fixed contracture was due primarily to long-standing PIP joint flexion or part of a more profound congenital anomaly. As shown in Table IV, there is a statistically significant relationship between fixed flexion, severity of contracture, and independence of superficialis V. All six infant hands had fixed PIP joint Ilexion, severe contracture. and dorsal flattening on x-ray; in five of the six superficialis V was absent. In this group fixed flexion was part of the original deformity, which suggests that it is part of the deformity rather than the result of long-standing PIP joint flexion. Perhaps the palmar soft tissues are affected by the same insult that deforms the lumbrical muscle and the head of the proximal phalanx. Tables II. III, and IV show that the status of superficialis V, the severity of contracture, and fixed contracture were valuable prognostic factors. Each one alone influenced the deformity and the results of treatment. In combination, the deformity was more severe and the treatment was less satisfactory, Age was also a prognostic factor. The result in infants was poor because these patients usually had the other unfavorable factors of severe and fixed contracture and absence of superficialis V. Perhaps more important, infants are unable to cooperate with postoperative immobilization and therapy. We have not had success with preoperative splinting of infants, although the experience of others24-‘6 suggests that we should make a greater effort. Even with successful splinting, we would recommend a tendon transfer to maintain correction. We have also had poor results in adults. Preoperative splinting was uniformly unsuccessful, and usually the time needed for postoperative therapy was more than they wished to spend. well.

of small Jinger

43

Our surgical treatment has evolved over the 10 years of this study as described. It has been suggested that only contractures of 60 degrees,” 70 degrees,** or more should be treated surgically. We have not operated on contractures of less than 30 degrees, but patients do well with contractures between 30 and 45 degrees. Contractures greater than 45 degrees are likely to be fixed and are operated on with the expectation that they can be improved to less than 30 degrees. We perform a soft tissue release of the PIP joint for residual contractures of more than 30 degrees. Superficialis V is used less frequently for transfer than superficialis IV. When the latter tendon is used, it is attached to both the extensor mechanism and the A2 pulley. Other tendons, such as the extensor indicis proprius could be used.” Regardless of how the deformity is corrected, a tendon transfer is needed to maintain correction. The surgical correction of camptodactyly should not be considered any more difficult or unpredictable than other operations on the hand. All patients should experience improvement. The extent of improvement will depend on the anatomic variants that have been discussed. REFERENCES I. McFarlane RM. Curry Gl. Evans HB. Anomalies of the intrinsic muscles in camptodactyly. J HAND S~JRG 1983;8:531-44. 2. Smith RJ, Kaplan EB. Camptodactyly

3.

4.

5. 6. 7. 8.

9.

10.

and similar atraumatic flexion deformities of the proximal interphalangeal joints of the fingers. J Bone Joint Surg 1968;50A: I187203. Engber WD. Flatt AE. Camptodactyfy: an analysis of sixty-six patients and twenty-four operations. J HAND SURG 1977;2:216-24. Millesi H. Camptodactyly. In: Littler JW, Cramer LM, Smith JW, eds. Symposium on reconstructive hand surgery. St. Louis: CV Mosby, 1974:175-7. Curtis RM. Capsulectomy of the interphalangeal joints of fingers. J Bone Joint Surg 1954;36A: 1219-32. Landsmeer JMF. Atlas of anatomy of the hand. New York: Churchill Livingstone. 1976;294-332. Zancolli EA. Structural and dynamic bases of hand surgery. 2nded. Philadelphia: JB Lippincott, 1978:168,174. Rozin MM, Hertz M, Goodman RM. A new syndrome with camptodactyly. joint contractures, facial anomalies and skeletal defects: a report and review of syndromes with camptodactyly. Chn Genet 1984;26:342-55. Koman LA, Toby EB, Poehling GG. Congenital flexion deformities of the proximal interphalangeal joint in children: a subgroup of camptodactyly. J HAND SURG 1990;15A:582-6. Mehta HJ. Gardner WU. A study of lumbrical muscles in the human hand. Am J Anat 1961;109:227-38.

The Journal of HAND SURGERY

McFarlane et al.

11. Eyler DL, Markee JE. The anatomy and function of the intrinsic musculature of the fingers. J Bone Joint Surg 1954;36A:l-9,18. 12. Basu SS, Hazary S. Variations of the lumbrical muscles of the hand. Anat Record 1960;136:501-4. 13. Brand PW, Beach RB, Thompson DE. Relative tension and potential excursion of muscles in the forearm and hand. J HAND SURG 1981;6:209-19. 14. Kaplan EB. Muscular and tendinous variations of the flexor superlicialis of the fifth finger of the hand. Bull Hosp Jt Dis 1969;30:59-67. 15. Lillmars SA, Bush DC. Flexor tendon rupture associated with an anomalous muscle. J HAND SURG 1988;13A: 115-9. 16. Courtemanche AD. Camptodactyly; etiology and management. Plast Reconstr Surg 1969;44:451-4. 17. Fumas DW. Muscle-tendon variations in the flexor compartment of the wrist. Plast Reconstr Surg 1965;36:

320-4. 18. Chowdhary DS. A rare anomaly of M. flexor digitorum sublimis. J Anat 1951;85:100-8. 19. Shrewsbury MM, Kuczynski K. Flexor digitorum su-

20.

21. 22.

23. 24.

25.

26. 27.

perficialis tendon in the fingers of the human hand. Hand 1974;6:121-33. Austin GJ, Leslie BM, Ruby LK. Variations of the flexor digitorum superficialis of the small finger. J HAND SURG 1989;14A:262-7. Currarino G, Waldman I. Camptodactyly. Am J Roentgenol 1964;92:1312-21. Buck-Gramcko D. Camptodactyly. In: Bowers WH, ed. The interphalangeal joints. Edinburgh: Churchill Livingstone, 1987:200-l. Upton J. Camptodactyly. In: McCarthy JG, ed. Plastic surgery. Philadelphia: WB Saunders, 1990;8:5328-37. Miura T. Non-traumatic flexion deformity of the proximal interphalangeal joint-its pathogenesis and treatment. Hand 1983;15:25-34. Hori M , Nakamura R , Inoue G, et al. Nonoperative treatment of camptodactyly. J HAND SURG 1987;12A: 1061-5. Siegert JJ, Cooney WP, Dobyns JH. Management of simple camptodactyly. J HAND SURG 1990; 15B:181-9. Gupta A, Burke FD. Correction of camptodactyly. J HAND SURG 1990;15B:168-70.

Carpal tunnel syndrome in children with mucopolysaccharidosis and related disorders Four cases of mucopolysaccharidosis are presented.

or mucolipidosis

and carpal tunnel syndrome in children

Carpal tunnel release achieved clinical and electrical improvement

in all cases.

(J HAND SURG 1992;17A:44-7.)

Claudia Gschwind, MD, and Michael A. Tonkin, Leonards, New South Wales, Australia

FXACS,

FRCS,

Ed (Orth),

St.

From the Hand and Microsurgery Unit, Royal North Shore Hospital, St. Leonards, Australia. Received for publication April 11, 1991; accepted in revised form June 19, 1991. No benefits in any form have been received or will be received from a commercial this article.

party related directly or indirectly

to the subject of

Reprint requests: Michael A. Tonkin, FRACS, FRCS, Ed (Orth), Hand and Microsurgery Unit, Royal North Shore Hospital, St. Leonards, 2065, New South Wales, Australia. 311131972 44

THE JOURNALOF HANDSURGERY

C

arpal tunnel syndrome is a rare compression neuropathy in children. It can, however, occur secondary to an underlying storage disease, such as mucopolysaccharidosis (MPS) or mucolipidosis (ML).ld MPS is divided into seven types.’ Each type lacks a specific enzyme for the metabolism of mucowhich accumulate in abnormal polysaccharides, amounts within and in between cells, particularly fibroblasts. Voluminous collagen with abnormal fibrillary characteristics is formed. The MLs are a group of re-