389

Ultrasonography of the normal and abnormal antenatal development of the upper limb F. DESCHAMPS, L. TEOT, N. B E N N I N G F I E L D , C. H U M E A U

S U M M A R Y : T h e degree o f s e v e r i t y o f c o n g e n i t a l d e f o r m i t i e s o f the h a n d , as well as a n y coexisting c o n g e n i t a l a n o m a l y s h o u l d be e v a l u a t e d especially if there is a p o s s i b i l i t y o f t h e r a p e u t i c t e r m i n a t i o n o f p r e g n a n c y . T h i s m a y be r e l a t i v e l y easy in the case o f s o m e m a j o r m a l f o r m a t i o n s w h i c h affect the n e u r o l o g i c a l or intellectual c a p a c i t y o f the child. It is h o w e v e r m o r e difficult in the p r e s e n c e o f p r e d o m i n a n t l y m o t o r a n o m a l i e s , a n d with d i s t a l l y b a s e d a n o m a l i e s o f the u p p e r l i m b w h i c h m a y be a m e n a b l e to later r e c o n s t r u c t i v e surgery. Ann Hand Surg, 1992, 11, n ° 5, 389-400.

KEY-WORDS : Upper limb. - - Hand. - - Development. - - Malformations. - - Ultrasonography.

INTRODUCTION

T E C H N I C A L ASPECTS

Prenatal analysis of limb development is now possible, due to the technological advance and to a better knowledge of the embryonic development. The use of high resolution endovaginal probes permits a close examination of the foetus, so that any morphological abnormality can be carefully documented. In addition, the ultrasound examination provides important information as to the future function of the hand and the upper limb and its range of m o v e m e n t . The discovery of an isolated malformation of the hand or the upperlimb should not of itself lead to an elective termination of pregnancy. A multidisciplinary team should be available to guide and advise the family. The upper limb analysis is not made in isolation but in the context of a general examination looking for malformation of the musculoskeletal system. It will be very precisely performed as the images are a source of useful information for the hand surgeons although they may need to confer with the radiologist in difficult cases.

The images of the developing limbs can be obtained with a variety of ultrasonographic equipments as long as one uses high frequency transducers. A 5 MHz transducer is preferred for transabdominal imaging and a 5 to 7 MHz transducer for endovaginal imaging. The use of high frequency transducers combined with the current technological levels in ultrasonographic equipment permits the precise evaluation of the upper limb throughout its development. The format of high frequency transducers suitable for this type of analysis varies from sector arrays to conventional linear and curved linear arrays in a variety of sizes. The format choper depends upon personal preference and

Laboratoire de la biologie de la reproduction, Maternitb, H6pital Arnaud de Villeneuve, 555, route de Ganges, 34059 M O N T P E L L I E R Cedex 1.

390

UL TRASONOGRAPH Y OF ANTENATAL DE VELOPMENT OF THE UPPER L I M B

formats available by a given ultrasound manufacturer. The ease or difficulty in obtaining adequate images for diagnosis depends largely on three factors : the security of the e q u i p m e n t used, - the body habitus of the patient, the skill of the ultrasonographer. Also for greater than ten the dynamic versus the static ultrasound study of the fetus has been the norm. -

-

ANNALS OF HAND AND UPPER LIMB SUR GERY

logical progress and to a better knowledge of embryonic development. The use of high performance endovaginal probes allows a very close examination of the foetus, so that any morphological abnormality can be carefully documented. It also allows an analysis of the foetus movements.

At the 7th week the embryo shows definite h u m a n characteristics. The head is still very large in size compared to the body, however the forearms raise progressively above the shoulder level and the hands often cover the m o u t h and the nose. This position is well demonstrated by the ultrasound images and represents a general EMBRYONIC DEVELOPMENT sign of good health. Differenciation of the seveAND ULTRASOUND CORRELATIONS ral segments is possible ; the hand forms simply a palette, the digital differenciation is not yet possible. At the end of the 8th week, the precar(fig. 1, 2, 4) [11, 12, 15] tilage is well differenciated. Articular slits will segment the limb. A first furrow separates the During the 4th week (stage 1) of development hand outline from the proximal part of the limb. ! 6 t h gestational week) the length of the embryo The proximal segment curve then appears is about 4 m m . Stage 1 corresponds to the appearance of the somites, which cause visible forming an angle with the lateral edge becoming undulations of the surface. Moreover, we can the elbow. The intermediary segment is then note the beginning of the formation of the bran- individualized in the forearm. The normal chial arches. The upper limb buds can be reco- ultrasound appearance is a biparietal diameter gnized by small b u m p s located on the lateral of 6 m m and an embryonic length of 25 m m . side of the body. The mesenchyme, which will Limbs can be demonstrated as very primitive form the buds, induces a thickening of the cove- buds. ring ectoderm. During the 9th week the posterior rotation of The ectoderm secondarily induces the me- the upper limb occurs. The upper limb develops senchymal differenciation in successive layers. first. The total duration of this series of events The proximal segment of the limb develops does not exceed 20 days. Development profirst. Then the development occurs in the area ceeds from proximal to distal (carpus, metacarbetween the ectoderm and the mesenchyme pus, digits) and from medial to lateral (mono(intermediary segment, then distal segment). dactyle, tridactyle). After the 9th week, indiviAt this stage the ultrasound examination will dual digits can be identified. At this stage, the only demonstrate the existence of cardiac pulsa- embryo is about 28 m m in length. The biparietal diameter is about 14 m m . The upper limb tions inside a c o m m a - s h a p e d appearance. From the 5th week of development (or 7th can be studied in different planes. gestational week) (stage 2), the length of the During the llth week, the entire embryo embryo is about 11 m m . The somite develop- !ength is about 45 m m , the biparietal diameter m e n t increases with the upper limb being in is about 18 m m , and the femoral length can be advance of the lower limb. Elbow and wrist measured. areas are identified, and the hand digital outliDuring the 12th week, the cephalo-caudal nes appear. By ultrasound, one can separate the cephalic area, the body and the upper limb out- length is about 22 m m , and the digits can be clearly separated (fig. 4). line forming a comma. After the 12th week, the whole hand is fully During the 6th week of development (8th gesrational week) (stage 3), the size of the embryo formed. The separate m o v e m e n t s of the digits is about 22 m m . Limbs develop and flex. Not- will be more clearly observed after the 15th ches appear between the outlines of the digits week (fig. 5 and 6). in the palette hand, indicating that the future Nowadays, amnioscopic images are rarely digits are present. The mesenchymal condensa- used for prenatal examinations because the protion which then occurs will differentiate into the cess can be dangerous for the foetus in contrast skeleton and the muscles. to ultrasound ; therefore we cannot provide inAntenatal ultrasound analysis of limb deve- formation regarding the correlation between the lopment is now possible, mostly due to techno- two examinations.

VOLUME 11 N ° 5 -- 1 9 9 2

U L T R A S O N O G R A P H Y OF A N T E N A T A L D E V E L O P M E N T OF THE UPPER L I M B

A•

391

'~

B.

C

Fig. 1. - - D i a g r a m m a t i c lines d e v e l o p m e n t from the 6th to the 10th w e e k of fetal life. Fig, 1. - - Evolution schematique de la formation des membres de la 6 e & la 10 e semaine de vie fetale. Fig, 1. - - Esquema evolutivo de la formacion de las extremidades desde la sexta a la decima semana de vida fetal.

A.U

B.

b°urge°n clu bras

'C. :

main en palette

6bauches des doigts

D.

E.

encoches entre les 6bauches des doigts

F.

doigts palm6s

doigts s~par~s

Fig. 2. - - A : Arm bud. B : Palet hand at 8th w e e k . C : Digital buds at 9th w e e k . D : Cleft b e t w e e n the digital buds at 10th w e e k , E : S e p a r a t e d digits at 11th w e e k . Fig. 2. - - A : Bourgeon du bras. B : Main en palette & la 8 e semaine. C : Ebauche des doigts a la 9 e semaine. D : Encoches entre les ebauches des doigts & la 10 e semaine. E : Doigts separes & la 1 le semaine. Fig. 2. - - A : Esbozo del brazo. B : Mano en paleta a la 8 ava semana. C : Esbozo de los dedos a la novena semana. D : Muesca entre los esbozos digitales a la decima semana. E : Dedos separados a la 11 semana.

B

C

D

E

F

Fig. 3. m B. C. D. E : Ultrasound views corresponding to figure 2. Fig. 3, - - B. C. D. E : Images echographiques correspondant aux schemas de la figure 2. Fig. 3. - - B. C. D. E : Ime,genes ecograficas correspondientes a la figura 2.

392

ULTRASONOGRAPHY OF ANTENATAL DEVELOPMENT OF THE UPPER LIMB

ANNALSOF HAND AND UPPER LIMB

SUR6ERY

Fig. 4. m Upper limb at 12th week. Fig. 4. - - M e m b r e sup6rieur & la 12 e semaine. Fig. 4, - - Brazoa a la 12 semana.

Fig. 6, m Hand at 15th week. Fig. 6. - - Main a la 15 e semaine. Fig, 6. - - M a n o a la 15 semana.

Fig. 5. - - Hand at 14th week. Fig. 5. - - Main & la 14 e semaine. Fig, 5. - - M a n o a la 14 semana.

Fig. 7, - - Longitudinal ultrasound view of the glenohumeral joint and the humerus. The arm is 90 ° abducted, 1. Cartilaginous upper humeral extremity. 2. Humeral diaphysis, 3, Acromion, 4. Clavicle. Fi 9. 7. - - Vue Iongitudinale 6chographique de I'articulation glenohum6rale et de I'humerus. Le bras est en abduction & 90 °. 1 : Extremite superieure de I'humerus cartilagineux. 2 : Diaphyse humerale. 3 : Acromion. 4 : Clavicule.

NORMAL ULTRASOUND FINDINGS OF THE HAND AND UPPER LIMB Primary ossification centres appear very early during intrauterine life. They are diaphyseometaphyseally located and form hyperechogenic areas of the sonographic views. Their length is measured during the foetal biometry. The cartilaginous epiphyses (especially the humeral head) are not echogenic and cannot be measu-

Fig. 7. - - Imagen ecografica longitudinal de la articulacion glenohumeral del h0mero. El brazo se encuentra en abducci6n a 90 °. 1 : Extremitad superiora del humero cartUaginoso. 2 : Diafisa humeral. 3 : Acromio. 4 : Clavicula.

red (fig. 7). Each segment will be analysed and measured comparatively to confirm the bone integrity, to detect a length discrepancy or another developmental abnormality (width, axis,

VOLUME 1 1 N ° 5 -- | 9 9 2

U L T R A S O N O G R A P H Y OF A N T E N A T A L D E V E L O P M E N T OF THE UPPER L I M B

393

Fig. 8. m Length measurement of the humerus (A) and forearm (B). The limits are marked by the junction between the echogenic diaphysis and the cartilaginous epiphyseal hypoechogenicity.

Fig. 8. - - Mesures des Iongueurs de I'humerus (A) et de I'avant-bras (B). Les limites sont marquees par la jonction entre la dialphyse hypoechogene et I'epiphyse cartilagineuse hypoechogene.

Fig. 8. - - Medida de la Iongitud del h~mero (A) y del antebrazo (B). Los limites esta.n demarcados por la union entre la diafisis hipoec6gena y la epffisis cartilaginosa hipoec6gena.

etc.) (fig. 8). Antenatal development criteria can be used. Standard deviations can be determined, comparing the length of the analysed segment with gestational age and the cranial circumference. The analysis will be more precise when using the ratio humeral length/radial length, looking for a rhizomielic or mesomelic malformation [6, 7, 8]. Humerus and shoulder

Clavicular symmetry will be systematically checked using a transverse view at the level of the glenohumeral joint and the upper part of the thorax. The shoulder m o v e m e n t s are rather difficult to analyse, because of the flexed position of the foetus. Yet we can ascertain normality of the limb m o v e m e n t s and observe, from the 12th week on, full m o v e m e n t s of arm abduction, flexion, scratching and limb m o v e m e n t s towards the m o u t h (fig. 9A and B). Occasionally, however, for technical reasons a good picture of the foetal limbs is not obtained, thus preventing analysis of the movements. At the humeral level, we can identify the primary ossification centers and the growth plate.

9a

Fig. 9a et b. - - Mouvements de succion du pouce.

9b

Fig. 9a and b. - - Thumb sucking movements.

Fig. 9a y b. - - Succion del dedo pulgar.

394

U L T R A S O N O G R A P H Y OF ANTENATAL D E V E L O P M E N T OF THE UPPER L I M B

ANNALSOF HAND AND UPPER LIMB SURGERY

Fig. 10. - - Rotational movements of the forearm. Fig. 10. - - Mouvements de pronosupination. Fig. 10. - - Movimientos de pronosupinaci6n.

Forearm and elbow

The forearm viewing is important to confirm the presence and the comparative length of the two bones [2]. It is mandatory to examine both sides. The elbow mobility during flexion/extension is easily seen. The length discrepancy between the two bones, that allows the rotational movements, can also be observed (fig. 10). Carpus and wrist

The hand lies in the same longitudinal axis as the forearm. Carpal bones are well differentiated from the 13th week on. Wrist mobility can be studied during the rotational movements of the wrist which appear at the end of the 10th week, when a significant amount of liquid coexists with a small fetal volume. The movement is confirmed by watching the hand change its rotational degree from the point of view of the examining probe. Digits and hand

The hand is seen fully at the end of the third month of pregnancy. Determination of the hand position in relation to the forearm is important to diag.nose abnormal position such as arthrogryposas multiplex congenita. Phalanges are identifiable as early as the 13th week, but the soft tissues remain unclear. The anatomical study of the hand can be done at this stage because the digital phalanges are clearly seen. The thumb appears in opposition to the four other digits. Finger mobility can only be analysed from the middle of the fourth month of pregnancy (fig. 11, 12, 13, 14, 15, 16, 17).

ULTRASOUND AND U P P E R LIMB PATHOLOGY General considerations [14]

The international medical community adopted unequivocally the classification of malformations proposed by Swanson et al. in 1976. In the case of antenatal diagnosis, the malformation will have to be assessed taking the gestational age into account. The aim of the examination is not to diagnose every malformation, which is almost impossible, but to reveal as soon as possible any significant malformation, where the prognosis could lead to a therapeutic termination of pregnancy. We wish to distinguish between isolated malformations that are relatively easy to discover, and associated groups of malformations. However, some isolated malformations like syndactyly, cannot be easily identified, because of the difficulties in obtaining a coronal view of the hand. Some malformations will be clearly demonstrated, but some others can only be visualized with difficulty. Upper limb malformations may be detected : a) during a routine ultrasound examination at the end of third month or in the 20th week of pregnancy, b) during a special examination indicated by : • other ultrasound indications : amniotic bands, hydramnios, polymalformation, • family history,

VOLUME 1 | N° 5 - 1992

ULTRASONOGRAPHY OF A N T E N A T A L D E V E L O P M E N T OF THE UPPER L I M B

395

13

11

12

Fig. 11 a n d 12. - - The open hand. 14

Fig. 11 et 12. - - La main ouverte. Fig. 11 y 12. - - La m a n o abierta.

Fig. 13. - - T w o first d i g i t s in extension. Fig. 13. - - Les d e u x premiers doigts en extension. Fig. 13. - - L o s d o s primeros d e d o s en extensi6n.

Fig. 14 and 15. - - Digits in flexion. Fig. 14 y 15. - - D e d o s en flexi6n. Fig. 14 et 15. - - Doigts en flexion.

15

396

ULTRASONOGRAPHY OF A N T E N A T A L D E V E L O P M E N T OF THE UPPER L I M B

ANNALSOF HAND AND UPPER LIMB SURGERY

Isolated malformations [2, 4, 5, 7, 8, 10, 13]

Fig. 16. - - T h e hand during grip movements. 1 : Palm. 2 : Digits in complete flexion. Fig. 16. - - La main dans le m o u v e m e n t de prise. 1 : Paume. 2 : Doigts en flexion complete.

Proximal transversal development arrest will be easily demonstrated by ultrasound when the two upper limbs are correctly visualized and if there is no oligohydramnios. The diagnosis of distal agenesis of the wrist and the hand can be done very early at the end of the third month when visualizing all the limb segments. This is easy by means of an endovaginal probe. The structures of the hand (carpus, metacarpal bones, phalanx) cannot be visualized in all planes. Their deformity will not be able to be conclusively diagnosed before the fifth month of pregnancy. This type of abnormality tends to be poorly accepted by the family. Our experience shows that the announcement of those malformations that are curable and compatible with a nearly normal life are better accepted when they are revealed during the last third of pregnancy, when the parents have less time left to worry as they prepare for the birth.

Fig. 16. - - La m a n o en m o v i m i e n t o de prensi6n. 1 : Palma. 2 : D e d o s en flexi6n completa.

Longitudinal development arrest - Radial club hand. The diagnosis can be made early (beginning of the fourth month). Ultrasound examination demonstrates the absence of the radius and the hand in a varus position. This malposition persists during the entire examination, and during the arm and forearm movements. This abnormality is generally unilateral. The dynamic study is unable to show any extension of the hand, which remains flexed but not rigid. The diagnosis is easier when there is a significant amount of amniotic fluid. The same ethical problems exist with this diagnosis. - The intercalary longitudinal development arrest or phocomelia is typically characterized by an absence of the intercalary segments (humerus, radius and ulna). The normal hand is in close contact with the scapula. Fig. 17. - - Open hand. 1 : Fifth ray : phalanx. 2 : Fifth ray : metacarpal bone. 3 : Wrist. Fig. 17. - - Main ouverte. 1 : 5 e r a y o n : phalanges. 2 : 5 e rayon : metacarpien. 3 : Poignet. Fig. 17. - - M a n o abierta. 1 : Quinta c o l u m n a : falange. 2 : Quinta c o l u m n a : metacarpo. 3 : Mufieca.

• contact with known keratogens: thalidomide, hydantoin, aminopterine, radiation, various fertilizers including organophosphorous products. Viral disease occuring in the first months of pregnancy is a well-known risk factor.

Failure of separation - Arthrogryposis Multiplex Congenita: the ultrasound diagnosis is easy ; this malformation is characterized by a malposition of the four limbs which may be unequally affected. Hydramnios is common. The morphological aspect of the bones is normal (radius and ulna), but the range of movements is very limited (fig.

18).

Syndactyly: digital dissociation can be clearly seen after the 15th week. Its absence must infer the diagnosis of syndactyly. Some difficulties remain to classify precisely the syndactyly (bone or skin).

VOLUME 11 N° 5 - 1 9 9 2

ULTRASONOGRAPHY OF ANTENATAL D E V E L O P M E N T OF THE UPPER L I M B

397

However, the foetus must be examined for associated (neurological, renal and gastro-intestinal) malformations. - A m n i o t i c bands : Congenital Constriction Band Syndrome (fig. 19) : amniotic bands are quite frequently observed. They seem to appear during the 4th m o n t h . Their nature is eften fib r o u s ; however, a systematic pulsed doppler or colour doppler study shows the existence of some vessels in these bands. The relatively late appearance on the ultrasound corresponds to peroperative findings of normal anatomical structures above and below the constriction bands. Associated deformities and general syndromes Fig. 18. - - Arthrogryposis multiplex congenita. 1 : Ulna. 2 : Radius. 3 : Thumb. 4 : Flexion contracture of the digits. Fig. 18. - - Artrogrifosis m01tiple congenita. 1 : Cubito. 2 : Radio. 3 : Pulgar. 4 : C o n t r a c c i o n de los d e d o s en flexion. Fig. 18. - - A r t h r o g r i p p o s e . 1 : Cubitus. 2 : Radius. 3 : Pouce. 4 : C o n t r a c t u r e des doigts en flexion.

Fig. 19. - - Congenital agenesia of the upper limb : amniotic band syndrom. 1 : Shoulder. 2 : Band. Fig. 19. - - A g 6 n e s i e du m e m b r e superieur : maladie amniotique. 1 : Epaule. 2 : Bride. Fig. 19. - - A g e n e s i a del m i e m b r o superior : s i n d r o m a de las bridas amioticas. 1 : H o m b r o . 2 : Brida.

- Isolated polydactyly. The digits must be systematically counted at the end of the 4th month. The diagnosis is made on the discovery of a medial or lateral b u m p or by the presence of a lateral extradigit which appears to be medial when the hand is closed. When this is an isolated deformity it is generally well accepted.

Lethal chondrodysplasias

Achondrogenesis is difficult to diagnose because it relies initially on subtle signs (short fem u r and h u m e r u s on the 10th percentile but with a subnormal abdominal and biparietal diameter, frontal cranial protusions and collapse of nasal bone). In thanatophoric dwarfism, on the contrary, the limbs are fingered and extremely short. All the segments are involved and hydramnios is invariable (fig. 20 and 20bis). The diagnosis is generally easy. Porak-Durante syndrome represents the nonviable form of osteogenesis imperfecta. The ultrasound appearance is evident from the 4th m o n t h of foetal life. The bones are irregular, and fractures are evident with various diaphyseal angulations, co-existant local hyperechogenicity corresponding to bones callus, and shortening of the fractured bones (fig. 21). The length ~ discrepancy )~ appears only around the 20th week. It is important to relate sonographically the relative lengths of a h u m e r u s or a radius and ulna to the cranial and abdominal perimeters between the 20th and the 25th weeks, in the event of dwarfism. Viable chondrodysplasias

Abnormalities affect the entire skeleton and the ultrasound examination confirms the existence of skeletal deformities in every limb. The shortening is generally in the region of 4 standard deviations. This particular study does not permit detailed descriptions of all pathological possibilities which are adequately described in the literature [ 13]. Campomelic dysplasia

C a m p o m e l i c dysplasia characterized by a progressive curvature of long bones mainly lo-

398

ULTRASONOGRAPHY OF ANTENATAL D E V E L O P M E N T OF THE UPPER L I M B

ANNALSOF HAND AND UPPER LIMB SURGERY

Fig. 21. - - Osteogenesis imperfecta (Porak and Durante). Bone are short. Local hyperechogenicities are the signs of the bone healing after spontaneous fractures. Fig. 21. - - Osteogenese imparfaite (Porak et Durante) les os sont courts. Les hyper~chog6nicit~s Iocalis~es sont le temoin de la cicatrisation osseuse apres fractures spontanees. Fig. 21. - - Osteogenesis imperfecta (Porak y Durante), los huesos son cortos. Las ima.genes hiperecogenicas Iocalizadas demuestran una cicatrizacion 6sea post fractura espontanea.

Fig. 20a and b. m Thanatophoric dwarfism: the short upper limb accompanies a general malformative disease. Fig. 20a et b : Nanisme thanatophore : le membre superieur court accompagne une maladie malformative g~n~ralisee. Fig. 20a y b. - - Enanismo Tanat6foro : el miembro superior corto se acompafia de una malformacion generalizada.

calized on the humerus and femur with associated hydrocephalus in 25 % of cases, cardiac malformations and severe intellectual impairment (fig. 22) [13]. This dysplasia is one of the viable chondrodysplasias, but therapeutic termination of pregnancy should be considered. Malformative associations

Meckel syndrome This polymalformation includes

Ultrasonography of the normal and abnormal antenatal development of the upper limb.

The degree of severity of congenital deformities of the hand, as well as any coexisting congenital anomaly should be evaluated especially if there is ...
8MB Sizes 0 Downloads 0 Views