Presentation on theme: "BIRTH DEFORMATIONS. INTRODUCTION Positional deformations: abnormalities mechanically produced by alterations of the normal fetal environment, which."— Presentation transcript:
INTRODUCTION Positional deformations: abnormalities mechanically produced by alterations of the normal fetal environment, which restrict fetal movement and/or cause significant fetal compression. Deformations of the extremities occur frequently because fetal movement is required for normal musculoskeletal development.
ETIOLOGY: DEFORMATIONS -intrinsic factors: risk for other fetal abnormalities -CNS disorder: primary neuromuscular Dz resulting in decreased fetal movement. -renal Dz resulting in decreased production of amniotic fluid & oligohydramnios, which increases the risk of fetal compression from outside forces. -extrinsic factors: generally otherwise healthy, primarily due to factors that lead to fetal crowding & restricted fetal movement.
Extrinsic Factors Oligohydramnios: from leakage of amniotic fluid Breech position: movement of the fetal legs are restricted due to entrapment between the body of the fetus & the uterine wall, the risk of deformations x10 folds. Abnormalities of the amniotic cavity: - the presence of uterine tumors or deformities (eg, bicornute uterus or septated uterus) - Multiple fetuses or very large fetus - Compression of the amniotic cavity affecting its size and shape due to a small maternal pelvis and the size of neighboring maternal organs - During the last trimester the impact of external factors increases as the fetus grows and the amniotic fluid decreases. As a result, positional deformities are more common in term infants than PT
The assessment of deformities in the NB a thorough PE: detect any neurological or other musculoskeletal abnormality that may have been an intrinsic cause of the deformity.
FOOT BONES: 1.Calcaneus 2.Talus 3.Navicular 4,5,6 = 3 Cuneiforms, 7.Cuboid, 8-12 = Metatarsal 13-17= Phalanges (2sesamoid bones underneath the head of 1 st metatarsal bone) (total= 28 bones/foot)
LOWER EXTREMITY DEFORMATIONS: Incidence= 4.2% (in 2,401 consecutive NB) Common foot deformities: -metatarsus adductus*: 76%, most common -positional calcaneovalgus: 18% -positional calcaneovarus (talipes equinovarus,clubfeet) Common leg deformities: -internal tibial torsion -external tibial torsion -physiologic genu varum: bow legs) >90% = normal feet, FU at 5-6 yrs. of age
1.Metatarsus adductus PE: forefoot, adduction while the hindfoot remains in a normal position, thus forming a "C" shape (concavity of the medial aspect of the foot) a deep medial crease generally present -in infant~ the most common cause of in-toeing -in walking child~ abnormal shoe wear Incidence: ~ 1-2 /1,000 similar in PT & term infants increased in -twin -F/H metatarsus adductus. -in 1 st born children (the increased molding effect from the primigravida uterus and abd.wall)
Metatarsus adductus Two classification systems have been used to evaluate the severity of this condition
Two classification systems have been used to evaluate the severity of this condition (show figure 1) .show figure 18 Evaluation of the severity: 2.Flexibility is determined by whether adduction can be corrected with manipulation back to the normal position. 1.the heel bisector no correlation with Px
Metatarsus adductus:severity 1.the heel bisector. in which the severity of metatarsus adductus is determined by the relationship of the toes to the projected axis of the foot that bisects the heel and normally extends through the second toe. The severity of the condition increases as the heel axis moves more laterally in relationship to the toes. However, the severity based upon this classification schema does not correlate with the prognosis. 2.the degree of flexibility of the forefoot. Flexibility is based upon the ability to correct the metatarsus adduction by providing lateral pressure on the forefoot over the first metatarsal while firmly holding the heel in a neutral position with the other hand. In infants with flexible metatarsus adductus, spontaneous correction generally occurs. Rx is reserved for those with rigid (severe) or moderately inflexible metatarsus adductus.
Metatarsus adductus Recent data: no association between DDH & metatarsus addusctus. (Hip exam. at every WCC visit until 2 yrs. of age). X-rays:-generally not necessary. -toddlers/older children with persistent deformity to determine if another condition, such as skewfoot (complex foot deformity: medial deviation of the forefoot, lateral translation of the midfoot & valgus hindfoot
Rx for metatarsus adductus Over 90% resolve without Rx, ~ the severity&the flexibility Mild- can overcorrect into abduction with little effort.. Rx not necessary: spontaneously resolve over time, Overcorrection with passive & active stretching may lead to mild abduction, stretching exercise should not be performed Moderate--will passively correct only to the neutral position. Passive stretching exercises & orthotic splint or corrective recommended, unclear efficacy Regular FU and casting if no improvement Severe or rigid- unable to be passively abducted to the midline. In these cases, corrective casting is required. Results are best with early Rx before 8 m. of age
Rx of metatarsus adductus x Without Rx or non-surgical Rx: excellent results in all patients with mild deformity without treatment and in 90% of the more severely affected feet 31 patients (45 feet) with metatarsus adductus who were followed for a mean of 32.5years. At initial presentation,12 patients (16 feet) with mild deformity received no Rx, and 20 patients (29 feet) with moderate and severe deformity were treated with serial manipulation and casting, one patient had bilateral involvement with no treatment on one foot and intervention on the other. No patient was treated with surgical correction. Below-knee plaster casting: of 65 infants with moderate (37 feet) and severe (48 feet) metatarsus adductus, corrected the deformity within 6-8 wk in all cases. At a mean FU of 4 yrs, correction was maintained in all children with initial moderate deformity; and of the 44 feet with severe deformity available for examination, 6 had a moderate deformity, 1 had a severe deformity, and the remaining maintained the correction. Surgical correction: controversial,may be an option for the older child with persistent metatarsus adductus, however the reported incidences are high for failure (~40%) & complications (~50%). Complications include skin slough and persistent pain with prominence of the tarsal metatarsal jts.
2.Positional calcaneovalgusfeet hyperdorsiflexion of the foot with the abduction of the forefoot, which often results in the forefoot resting on the anterior surface of the lower leg. External tibial torsion: a common asso.finding more common: in first-born children due to the increased molding effects of the primigravida uterus.
Positional calcaneovalgus (talipes calcaneovalgus) newborn infant at rest
Positional Calcaneovalgus feet DDx:mandatory DDx: more severe conditions -Congenital vertical talus (rock bottom feet): rare condition, frequently associated with neuromuscular & genetic disorders (eg, trisomy 13,14,15), a fixed dislocation of the navicular dorsolaterally on the head of the talus. The ability to correct (or partially correct) the deformity with gentle pressure usually distinguishes the more flexible calcaneovalgus feet from the rigid congenital vertical talus. X-rays, if PE is inconclusive. -Paralytic calcaneus foot deformity is seen in infants with a neuromuscular disorder (eg, myelodysplasia or polio), which results in the absence or paralysis of the gastrocsoleus muscle. The PE to detect a motor deficit should differentiate between paralytic & positional calcaneovalgus feet. -Posteromedial bow of the tibia: both a calcaneovalgus foot & a bowed, shortened tibia. PE: a leg-length discrepancy. Bowing of the tibia (X-rays) Rx: Most cases of positional calcaneovalgus feet: spontaneously resolve. If the foot cannot be plantar-flexed below neutral, casting is indicated. Surgical Rx is not required.
3. Positional “clubfoot” (talipes equinovarus) involves both foot & lower extremity, foot=excessively plantar flexed, with forefoot swung medially and the sole facing inward.
CLUB FEET:CLASSIFICATIONS 1.Congenital clubfoot: the most common type, usually an isolated anomaly 2.Syndromic clubfoot: associated with intrinsic etiologies of clubfeet: connective tissue, genetic, neuromuscular disorder, or syndrome 3.Positional clubfoot: due to intrauterine crowding or breech position, not a true club foot, as opposed to a true clubfoot, it easily corrects to a normal position with manipulation & will resolve over time.
ROTATIONAL DEFORMITIES OF THE LEGS Rotational variations of the foot position to the leg often occur in younger children due to in-uterine positioning. In utero, the fetus's Hips: typically flexed, abducted, & externally rotated, lower legs: internally rotated and the knees: flexed. With intrauterine crowding and mechanical restriction, this position predisposes the fetus to rotational deformities: int. & ext. tibial torsion and ext.rotation of the hips, which may result in physiologic genu varum.
4. Internal tibial torsion -a normal rotational variant & due to intrauterine positioning, -the most common cause of in-toeing -may also be associated with metatarsus adductus & genuvarum -2/3 = bilat. -In unilat. cases: the lt. side is more frequently affected.
TFA (The thigh-foot angle) the angular difference between the axis of the foot and thigh when the patient is in prone position with knees flexed 90 degrees, & foot & ankle neutral position The normal TFA = +10 to +15 degrees. Internal tibial torsion = negative TFA
Rx: Internal Tibial Torsion Spontaneous resolution of internal tibial torsion occurs with ambulation and normal growth, so no intervention is generally required. Improvement is typically observed 6-12 mos. from the time the child walks, and complete resolution is expected in most children by 4 years of age. Surgical Rx is rarely indicated and is reserved for the older child with marked functional or cosmetic deformity (ie, thigh-foot angle is abnormally negative, with values below -10degrees).
5. External tibial torsion -a normal rotational variant due to intrauterine positioning -the most common cause of out- toeing in infants & young children -usually identified when the child begins to walk. -often accompanied by positional calcaneovalgus.
PE: External Tibial Torsion The normal TFA= +10 to +15 degrees. External tibial torsion: the TFA is abnormally positive with values= +30 to +50 degrees.
Rx: External Tibial Torsion This condition typically follows a similar course of internal tibial torsion, with spontaneous resolution over time. However, disability (eg, knee pain patellofemoral instability) is more common in children with persistent external tibial torsion than in those with internal tibial torsion. Increased external tibial torsion is also associated with neuromuscular disorders including myelodysplasia and polio. As a result, a careful neurologic examination should be performed in patients with this finding. As with other positional deformities, intervention is usually not required as the majority of affected children will have spontaneous resolution. Significant improvement does not occur until the child has achieved independent ambulation. External tibial torsion is more likely to persist through adolescence than internal tibial torsion. Surgical Rx is rarely indicated and is reserved for the older child with marked functional or cosmetic deformity (ie, thigh-foot values > +40 degrees).
6. Physiologic genu varum (bowlegs) Common: due to intrauterine positioning, caused by a combination of external rotation at the hip due to the tight posterior hip capsule & internal tibial torsion, typically identified in the older infant or toddler shortly after the start of ambulation. Usually bilateral, the severity between the limbs may vary. In-toeing is generally seen during ambulation. During ambulation, the child may compensate for his in- toeing by externally rotating the tibia to put the foot in a neutral position. This causes further external rotation of the femur and subsequent exaggeration of the deformity. Spontaneous resolution occurs between 18-22 mos. with stretching of the hip capsule and resolution of the internal tibial torsion.
Bowlegs:genu varum A pathologic disorder: more likely if worsening during infancy, unilateral, knee instability, or pain. Pathologic causes: Blount's disease (tibia vara), rickets, and fibrous dysplasia. Hx, PE & full-length bilat. standing radiographs can DDx physiologic vs. pathologic (requires Rx) genu varum In Blount's dz, the most common cause of pathologic genu varum, the characteristic radiographic finding is acute medial angulation (beaking) of the proximal medial metaphysis of the tibia.(may not be present until 2-3 y.of age.)
Rx: Knock Knees Unlikely to correct if: >15 cm & after 6 y. of age Surgical Rx in: -skeletally immature= surgical Rx medial tibial epiphyseal hemiepiphysiodesis -skeletally mature = osteotomy at the center of rotation of angulation & is usually in the distal femur