CONGENITAL ANOMALIES ANDNORMAL SKELETAL VARIENTS.pptx a.pptx final ppt.pptx

CONGENTITAL ANOMALIES OF THE SKLETAL SYTEM

1. CONGENITAL ANOMALIES AND NORMAL SKELETAL VARIANTS PART II Moderator : Dr Mounisha Ma’am Presenter : Dr Sanath S

2. CONTENTS ANOMALIES OF HIP AND PELVIS ANOMALIES OF UPPER LIMB ANOMALIES OF LOWER LIMB NORMAL SKELETAL VARIANTS

3. ANOMALIES OF THE HIP AND PELVIS DEVELOPMENTAL DYSPLASIA OF THE HIP Congenital hip dysplasia, congenital hip dislocation (CHD ). Developmental dysplasia of the hip (DDH) is the current preferred term used to describe a spectrum of conditions that range from irreducible dislocation of the hip at birth to neonatal hip instability. The condition has been previously described as congenital hip dislocation and congenital hip dysplasia

4. Fixed dislocation at birth is estimated at 1:1000 births and late dislocation, subluxation, and dysplasia at 0.4-0.6:1000 births. Female predominance - as high as 6:1. If one of the parents has had DDH, then the risk for the first child is 12%. Bilateral but asymmetrical dysplasia can occur in up to 25% of cases. Known risk factors for DDH include breech fetal presentation, oligohydramnios, and firstborn status. Known associated abnormalities include neuromuscular disorders, congenital torticollis, and skull and foot deformities.

5. Pathophysiology of DDH Multifactorial - shallow bony margin; delayed ossification of the acetabulum or femoral head; ligamentous laxity; and neuromuscular disease with shortening, weakness, or contractures. Hip flexion associated with breech presentation induces DDH by causing shortening of the psoas and decentering of the femoral head.

6. Physical examination A palpable hip “click” can be elicited when combined external rotation-abduction and internal rotation-adduction are alternately applied to the flexed hip (Ortolani’s test and Barlow’s test). Diagnostic ultrasound is the first choice for imaging investigation.

7. The postnatal diagnosis within the 1st year is best assessed with ultrasound. Plain films can show bony changes in this period but do not depict cartilaginous abnormalities of the unossified femoral head or cartilaginous labrum. Plain films may appear normal in the first 2-3 months but subtle signs can be evident at 6 weeks. Plain films are most useful from 2 to 8 months and reliable depiction of DDH can often be made after 4-6 months.

8. The classic findings are (Putti’s triad). Absent or small proximal femoral capital epiphysis. Lateral displacement of the femur. Shallow acetabulum with an increased inclination of the acetabular roof, usually > 30°.

9. DEVELOPMENTAL DYSPLASIA OF THE HIP, PUTTI’S TRIAD. AP Pelvis. Observe the three classic findings of DDH: Small hypoplastic femoral capital epiphysis (arrow), Lateral and superior subluxation of the femoral head, and A shallow acetabulum. The contralateral hip is normal in alignment and bony development

10. In adolescents and adults, long-standing dislocation manifests as- A shallow acetabulum and a large, flattened femoral head with superior and lateral displacement. The head is at risk for complicating avascular necrosis. On occasions a neo- or pseudo-acetabulum is formed on the posterosuperior surface of the iliac wing.

11. Neglected DDH – with pseudoacetabulum formation

12. DEVELOPMENTAL DYSPLASIA OF THE HIP, ADULT PRESENTATION. AP Hip. Observe the deformity and flattening of the femoral head. The acetabulum is shallow. B. AP Pelvis. Observe the shallowness of the original acetabulum (arrow) compared with the accessory acetabulum, which has formed on the lateral edge of the ilium. C. AP Pelvis. There is complete bilateral dislocation of the femoral heads from the acetabuli , both of which are shallow.

13. 8 YEAR OLD FEMALE C/O SHORTENING OF LEFT LOWER LIMB- NOTICED AT 2 YEARS OF AGE LIMP DEPARTMENT CASE

14. 2) COXA VARA AND COXA VALGA The normal femoral angle of incidence (Mikulicz’s angle, neckshaft angle) between the femoral neck and shaft ranges between 120° and 130°. An angle < 120° is designated as coxa vara, and one > 130° coxa valga .

15. Either of these deformities can be unilateral or bilateral, occur as an isolated finding as a result of local causes, or be found in association with systemic metabolic disease or skeletal dysplasia. The proximal femoral physeal plate has a unique “bifid” growth pattern that contributes to producing the deformities— the medial portion grows twice as rapidly as the lateral portion.

16. Coxa Vara Description . Failure of medial growth of the physeal plate produces the femoral deformity of coxa vara. Clinical Features . Painless limp. Radiologic Features . The femoral neck is short and broad with a relatively large greater trochanter. The femoral angle is < 120°.

17. Frequently there is evidence of disturbed growth at the medial metaphysis, where there may be a characteristic triangular fragment, cortical irregularity, radiolucency, and a growth arrest line that is closely apposed to the physis. The physis is more steeply orientated and often wider than normal. The acetabulum may be slightly deformed. Secondary degenerative joint changes may be superimposed in adults.

18. COXA VARA. A. AP Pelvis. In this pubescent female patient with open growth plates there is a decreased femoral angle with an inverted radiolucent “V” in the proximal metaphysis of the femur (arrow). This is a characteristic appearance for infantile coxa vara. An associated widening of the metaphysis is related to the deformity. B. AP Hip. Later into adolescence the triangular fragment is incorporated into the femoral neck, with reduction of the femoral angle and broadening of the neck (metaphysis). The greater trochanter is enlarged and elevated secondary to the deformity, which produces a Trendelenburg-type gait.

19. Coxa Valga Clinical Features . The most common causes are from neuromuscular disease, especially cerebral palsy, with a lack of mechanical stimulation to the growth plate and muscle imbalance. Radiologic Features. The femoral neck is elongated and slender, and the femoral angle exceeds 130°. The proximal femoral growth plate is close to horizontal, and the acetabulum is usually shallow, with the femoral head laterally subluxed.

20. 3) SACRAL AGENESIS Synonyms - Caudal regression syndrome, sacrococcygeal agenesis. Description - Sacral agenesis is part of a spectrum of conditions labeled caudal regression syndrome, in which there is congenital absence of one or more segments of the sacrum. More extensive cases also demonstrate absence of lumbar and thoracic segments.

21. The anomaly was first reported by Hohl in 1850. Up to 20% of cases have diabetic mothers. At birth, the sacral region is flat or depressed with deficient musculature of the lower extremities. Associated problems include intestinal and urinary anomalies, spinopelvic instability, scoliosis (most common), myelomeningocele, hip dislocation or contracture, knee contracture, and foot deformity. A rare finding is the sirenomelus deformity (mermaid syndrome), in which the legs are fused and the feet are absent

22. Radiological features: The sacrum and possibly some of the caudal lumbar segments are absent. The two iliac bones are small and closely apposed, often in contact with each other (bird-like pelvis ).

23. CAUDAL REGRESSION SYNDROME. AP Lumbosacral Spine. Failure of formation of the sacrum creates close proximity of the posterior iliac surfaces. Degenerative reactive sclerosis on approximated iliac surfaces.

24. CAUDAL REGRESSION SYNDROME. A. Lateral Lumbar Spine. Note the absence of the sacrum and the L5 vertebra. The lowest lumbar vertebra present is L4. B. AP Pelvis. The sacrum is not present and the approximation of the ilia can be noted.

25. ANOMALIES OF THE LOWER EXTREMITY 1) BIPARTITE, TRIPARTITE, AND MULTIPARTITE PATELLAE Description. The patella is the largest sesamoid bone in the body and normally develops a single ossification center in the 5th or 6th year of life. Failure of complete ossification can result in isolated segments: a bipartite patella has two pieces, a tripartite patella has three pieces, and more than three pieces is called a multipartite or segmented patella

26. The most common form is the bipartite patella, characterized by an isolated smaller fragment located at the superolateral quadrant of the patella. It occurs in 2-3% of the population, with bilateral presentation in 40-80% of cases. Males are predominantly affected with male to female ratios as high as 9:1. The exact cause of the fragmentation is usually unclear, although chronic trauma during ossification is thought likely. The superolateral location of the bipartite variant may relate to insertional stress from the vastus lateralis. The fragments are usually united by fibrous union, although in the uncommon symptomatic cases these may be disrupted and require excision.

27. Radiologic Features. Routine AP, lateral, and tangential radiographs are surprisingly unrewarding at times for visualization of the separate ossicles . Radiographs taken in the PA position will often show better definition of the patella and should be considered for any circumstance in which evaluation of the patella is a priority. An externally rotated oblique view may also be useful for accurate depiction.

28. Bipartite Patella, AP Knee. smoothly marginated separated segment at the upper outer pole of the patella. Tripartite Patella, AP Knee. two separated fragments in the same location. Bipartite and tripartite patellae almost always occur on the superolateral margin of the patella. They should not be confused with patellar fracture because fractures usually occur through the waist of the patella and do not have smooth, sclerotic margins.

29. A stress tangential view in the squatting position may show separation of the fragments as a sign of fibrous attachment disruption. The sclerotic, smooth bony margins and characteristic location of the separate ossicles usually allows for differentiation from acute fracture. Nuclear bone scan can be useful in symptomatic cases, demonstrating increased uptake at the fragment junction zone as a manifestation of disruption. MRI can also depict signs of disruption, with localized bone marrow and soft tissue edema , as well as fluid within the fibrous disruption.

30. SESAMOID BONES AND OSSICLES OF THE KNEE Sesamoid bones and other ossicles at the knee are common, and knowledge of their appearances and locations is important, especially in the differential diagnosis of intra-articular loose bodies. Three of the most common include the fabella, cymella , and meniscal ossicle.

31. FABELLA. Lateral Knee. The small corticated spherical radiopacity present in the popliteal fossa (arrow) represents a fabella. COMMENT: A fabella is a normal sesamoid bone within the lateral gastrocnemius tendon. This should not be confused with an intra-articular osteochondral fragment from osteochondritis dissecans or a loose body from synoviochondrometaplasia . On the AP projection the fabella typically is seen overlying the lateral femoral condyle, which assists in differentiating these conditions

32. A cyamella   is a rare  sesamoid bone  that exists as a normal variant within the  popliteus tendon , characteristically located at the lateral aspect of the distal  femur  in the popliteal groove . Cyamella is best seen on the AP view of plain radiograph as opposed to  fabella , which is best appreciated on the lateral view .

33. MENISCAL OSSICLE. AP Knee. Focal triangular ossification complete with cortex within the lateral margin of the medial meniscus (arrow). COMMENT: Meniscal ossicles are found in about 1% of knees and are usually of no significance, though they have sometimes been found in tandem with meniscal tears. They are commonly confused with osteochondral fragments

34. TARSAL COALITION Synonyms. Tarsal bar, tarsal fusion. Description. Tarsal coalition is a congenital condition of fibrous, cartilaginous, or bony union of two or more tarsal bones. These can be congenital or acquired as a result of infection, trauma, inflammatory arthritis, or surgery. There is a failure of mesenchymal segmentation during early embryonic development. Up to 50% of coalitions are bilateral. The most common site is at the calcaneonavicular joint, which accounts for 50% of cases. The second most common site (35%) is the talocalcaneal joint. Less common fusion patterns include talonavicular and calcaneocuboid and entire fusion of the tarsus.

35. Many cases remain asymptomatic throughout life. Foot and ankle pain begins in the 2nd and 3rd decades, often triggered by relatively minor trauma or athletic activity. Tarsal coalition can be a cause of chronic inversion injuries to the ankle and should be looked for in patients with such histories. Tarsal coalition is probably the most commonly missed diagnosis clinically and radiologically in persistent pain syndromes of the foot and ankle.

36. Calcaneonavicular Coalition. The most common site for coalition and requires the medial oblique view of the foot for optimum demonstration . Osseous fusions are marked by continuous bony trabeculae and will be seen only after 8-12 years of age. Cartilaginous and fibrous connections may be inferred by elongation of the anterior process of the calcaneus (anteater sign), with sclerosis and irregularity of the opposing margins at the coalition site. CT is more conclusive for the same findings, whereas MRI will show the intermediate signal of the connecting tissue. Bone marrow edema at the site of fusion is common and best seen on fat-suppressed, STIR or proton density sequences.

37. TARSAL COALITION. A. Lateral Foot. Large bony bar projecting from the anterior process of the calcaneus (arrow) (anteater sign). B. Medial Oblique Foot. The site of fibrous union is marked by sclerosis and frayed margins of the opposing anterior calcaneal process and navicular (arrow). This is the optimum view for plain film diagnosis. COMMENT: Tarsal coalition often goes unrecognized and may be the underlying cause of chronic inversion injuries of the ankle or non-responsive hindfoot pain.

38. VERTICAL TALUS Synonyms. Rocker bottom foot. Description - Congenital vertical talus is an anomaly consisting of vertical orientation of the talus in which the head is orientated inferiorly and a dorsally dislocated navicular lies on the dorsal surface of the talar neck. Clinical Features.- The vertical orientation of the talus appears to be the result of a short Achilles tendon. The characteristic physical deformity is known as the rocker bottom foot because of the rounded prominence on the medial plantar surface. It is often associated with spina bifida manifesta, myelomeningocele and Down’s syndrome. Males and females are equally affected, and presentation is bilateral in 50% of patients

39. VERTICAL TALUS. A. Bilateral Lateral Ankles. The talus (T) has assumed a vertical position bilaterally.

40. SESAMOID BONES AND OSSICLES OF THE FOOT AND ANKLE OS TRIGONUM. Lateral Ankle. Smoothly corticated separated ossicle ( os trigonum) at the posterior talar margin (arrow). COMMENT: The os trigonum is caused by a failure of union of the secondary ossification center at the posterior aspect of the talus. It usually is of no clinical significance but in athletes can precipitate a painful impingement syndrome ( os trigonum syndrome)

41. OS TRIGONUM SYNDROME. A. T1-Weighted MRI, Sagittal Foot. The os trigonum is visible as a separated ossicle at the posterior aspect of the talus (arrow). B. Inversion Recovery with Fat Saturation MRI, Sagittal Foot. The water-sensitive sequence shows bone marrow edema at the opposing contact subchondral surfaces of the os trigonum and talus as localized high signal (white areas; arrowheads). COMMENT: This bone marrow edema is secondary to chronic motion across the site of separation and is frequently pain producing . MRI and nuclear bone scan studies are the techniques of choice to determine when an os trigonum is involved in posterior impingement syndromes

42. OS TIBIALE EXTERNUM. A. Lateral Foot . Well-defined bony density overlying the anterior process of the calcaneus and navicular (arrow). A co-existing os trigonum is also evident (arrowhead). B. Lateral Oblique Foot. The smoothly corticated separated ossicle is shown (arrow). COMMENT: This variation can be seen in 10-15% of the population in various forms. This free rounded ossicle form (type I) is rarely associated with symptoms, though it may cause a palpable bony bump. A more closely apposed triangular form (type II) is more commonly symptomatic

43. DEPARTMENT CASE Fusion of the ossicle to the navicular, producing an elongated, curved navicular (cornuate navicular)

44. OS INTERMETATARSEUM. Dorsoplantar Foot. Smoothly corticated supernumerary metatarsal fused to the second metatarsal (arrow). COMMENT: The anomaly may manifest, as in this case, with fusion of the ossicle to the metatarsal or as a separated bony fragment. The majority are asymptomatic

45. HALLUX SESAMOID BONES. A. Bipartite Single Sesamoid (arrow). B. Bipartite Double Sesamoid (arrows). C. Tripartite Single Sesamoid (arrow). COMMENT: The plantar sesamoids are found in the flexor halluces brevis tendons. These sesamoid bones have a wide spectrum of appearances, as demonstrated, and care should be made to not identify the partite variations as fracture lines

46. ANOMALIES OF THE UPPER EXTREMITY 1) SUPRACONDYLAR PROCESS OF THE HUMERUS Synonyms. Supracondyloid process, supraepitrochlear process, epicondylic process, supracondylar spur. Description. Supracondylar process, a rudimentary exostosis of bone present on the anteromedial aspect of the distal humeral metaphysis 5-7 cm above the medial epicondyle, may be seen in up to 3% of the population. Clinical Features. The majority of these anomalies remain clinically asymptomatic, but fracture or local neurovascular compression may result in symptoms.

47. The median nerve and brachial artery are the most commonly compressed structures, either beneath the bony spur or from an anomalous fibrous ligament traversing from the medial epicondyle to the supracondylar process ( Struther’s ligament). Less commonly, the ulnar nerve or both the ulnar and median nerves can be compressed, especially if Struther’s ligament inserts more distally in the cubital fossa.

48. Radiologic Features. On lateral and oblique views of the elbow or humerus a curved, beak-like corticated bony exostosis can be seen originating from the distal humeral metaphysis, which is usually not > 2 cm in length. Characteristically, it is curved and tapered inferiorly, with its apex directed toward the joint, differentiating it from the benign bone tumor osteochondroma, which typically is orientated away from an adjacent joint.

49. DISTAL HUMERUS, SUPRACONDYLAR PROCESS. Lateral Elbow. Curved, slender bony spur projecting from the anterior distal diaphyseal surface of the humerus and orientated toward the joint (arrow). COMMENT: The supracondylar process projects toward the joint, a helpful differential point from an osteochondroma, which projects away from the joint. The supracondylar process is usually asymptomatic but sometimes creates a compression neuropathy of the median nerve, especially if trauma is sustained

50. 2) RADIOULNAR SYNOSTOSIS Description. A failure of longitudinal segmentation of the radius and ulna results in fusion of the two bones, most commonly at the proximal end. This defect is transmitted as an autosomal dominant, with an equal male to female incidence. Clinical Features. The anomaly may be seen unilaterally, but is bilateral in 80% of cases. The length of the fusion may extend from 3 to 6 cm and may be osseous or fibrous. clinically pronation and supination may be limited to non-existent. Associated conditions include congenital dislocated hip, clubfoot, Madelung’s deformity, syndactyly, or polydactyly.

51. Radiologic Features. This diagnosis can be made on AP and lateral views of the elbow. These will demonstrate bony union of the proximal radius and ulna, for a distance of up to 6 cm RADIOULNAR SYNOSTOSIS. Lateral Elbow. Observe the congenital fusion of the proximal interosseous space between the radius and the ulna (arrow).

52. RADIOULNAR SYNOSTOSIS

53. 3) MADELUNG’S DEFORMITY. Description. Madelung’s deformity was first defined in 1878 by a German surgeon, Madelung, who described a young woman with a deformity of her wrist. Clinical Features- The deformity consists of a short bowed radius, volar and ulnar tilt of the distal radial articular surface, and dorsal dislocation of a relatively long ulna at the distal radioulnar articulation. The basic defect appears to be premature fusion of the medial aspect of the distal radial epiphysis. Four types are recognized according to cause: traumatic, dysplastic (e.g., dyschondrosteosis), genetic (e.g., Turner’s syndrome), and idiopathic.

54. The diagnosis is usually made when wrist pain develops in early adolescence, subsequently resolving on closure of the growth plate. Carpal tunnel syndrome and, rarely, spontaneous rupture of the extensor tendons can occur. The physical appearance of the resulting wrist deformity has been called the bayonet appearance. The posteriorly dislocated ulna is mobile and can be repositioned manually, although only temporarily. A spectrum of variations can occur, ranging from less severe forms to a reversed Madelung’s deformity, in which the distal radial articular surface is tilted dorsally and the ulna ventrally.

55. MADELUNG’S DEFORMITY. A. PA Wrist. Premature closure of the medial portion of the distal radial physis has created an ulnar slant to the distal articulating surface of the radius. A characteristic V-shaped deformity is present on the ulnar side of the distal radius (arrow). B. Lateral Wrist. Note the characteristic posterior subluxation of the ulna, which has been referred to as the bayonet deformity (Madelung’s deformity).

56. 4) ULNAR VARIANCE Synonyms. Radioulnar index, short ulna syndrome, ulnar abutment syndrome. Description. If the radius and ulnar articular surfaces are in the same plane, the configuration is termed neutral variance and is normal. When the ulna is relatively short, the appearance is referred to as negative (minus) ulnar variance, and if the ulna is longer it is a positive (plus) ulnar variance. Clinical Features. The relative lengths of the radius and ulna are important factors in dispersing compressive forces across the proximal carpal joint. Ulnar variance may occur as a developmental (idiopathic) variant or secondary to traumatic or inflammatory causes, including juvenile rheumatoid arthritis. A change in variance of 1 mm can alter the radioulnar mechanical transfer characteristics by 25%, which has marked implications for individuals who perform repetitive loaded rotational movements.

57. A) Negative Ulnar Variance. Shortening of the ulna has been implicated in avascular necrosis of the lunate (lunate malacia , Kienböck’s disease). Separation of the scaphoid from the lunate owing to disruption of the scapholunate ligament (scapholunate disassociation) with rotation of the scaphoid can have a short ulna in up to 50% of cases. When the ulna is very short (> 5 mm disparity), a painful pseudo-arthrosis can develop between the radius and the ulna (radioulnar impaction syndrome).

58. NEGATIVE ULNAR VARIANCE. A. PA Wrist. The head of the distal ulna lies proximal to the articular surface of the radius. B. Complicating Kienböck’s Disease, PA Wrist. In this case there is marked negative ulnar variance with sclerosis and collapse of the lunate owing to avascular necrosis ( Kienböck’s disease). The long-standing collapsed lunate has resulted in mild narrowing of the radiocarpal joint with resultant degenerative subchondral cysts in the subarticular bone of the distal radius.

59. B) Positive Ulnar Variance. Elongation of the ulna, especially when the ulnar styloid is enlarged, results in mechanical impingement onto the lunate and triquetral bones (ulnar abutment syndrome, ulnar impingement syndrome). The triangular fibrocartilage is developmentally thin. In addition, the extra stress through the triangular fibrocartilage complex may lead to painful perforations, tears, and degenerative disease. Premature closure of the radial epiphysis from acute trauma or repetitive chronic trauma, such as in gymnastics, is commonly the cause

60. ULNAR ABUTMENT SYNDROME. A. Positive Ulnar Variance, PA Wrist. Note that the ulnar head (arrow) lies distal to the articular surface of the radius (arrowhead). The adjacent articular surface of the lunate is slightly angular as a manifestation of chronic ulnar head impaction. B. Enlarged Ulnar Styloid Process, Oblique Wrist. Observe that the ulnar styloid process is elongated and large (arrow) despite the presence of negative ulnar variance. The styloid tip is sclerotic along with the opposing dorsal planar surface of the triquetrum, which has a smooth sclerotic surface (arrowhead). Delayed Bone Scan, PA Wrist. Focal increased uptake corresponding with the impaction sites between the elongated ulnar styloid and the opposing triquetrum confirms the chronic bony abutment syndrome of the two structures. COMMENT: Two manifestations of ulnar abutment syndrome have been demonstrated: positive ulnar variance and elongated ulnar styloid process. Both of these findings are frequently overlooked on plain film studies. Bone scan and MRI studies often suggest the diagnosis because of focal isotope uptake or increased signal from edema on T2-weighted studies

61. 5) CARPAL COALITION Synonyms- Carpal fusion. Description. Carpal coalition is the fusion of two or more carpal bones. Clinical Features. Acquired fusions occur in infections, inflammatory arthritis, and trauma and following surgery. Congenital unions may occur as an isolated anomaly or as part of a skeletal dysplasia. Isolated congenital fusions typically affect the bones in one row of the wrist (i.e., proximal or distal), whereas fusions that cross from one row to the other tend to be associated with dysplasias . Congenital carpal fusion is due to the result of a failure of embryonic cartilaginous segmentation and joint formation. Carpal coalition is more common in males and has a higher incidence in blacks. Up to 60% can be bilateral.

62. Many combinations of coalition have been described, although the most common fusion of the wrist is between the lunate and the triquetral bones. Others include capitate-hamate, trapezium-trapezoid, and pisiform-hamate. The majority are asymptomatic, although cystic change, degenerative joint disease, and increased risk for fracture have all been described. Lunate-triquetral fusions may be associated with scapholunate ligament disruption, leading to instability.

63. CARPAL COALITION. PA Wrist. Observe the congenital synostosis of the lunate and triquetrum and the site of fusion (arrow).

64. Standard PA views show the coalitions of the proximal carpal row the best, but oblique and lateral projections should be routinely employed in assessment. Loss of joint space and continuity of cortical and trabecular bone between adjacent carpal bones is demonstrated. Diagnosis will be delayed until ossification is radiographically evident; it may be as late as 15 years of age before diagnosis can be confirmed. In lunate-triquetral fusions, the scapholunate space may be widened owing to disruption of the scapholunate ligament. In the presence of wrist pain MRI examination may be useful to confirm the status of the intrinsic carpal ligaments, the triangular fibrocartilage, and Kienböck’s disease of the lunate .

65. POLYDACTYLY Description. Polydactyly is an increased number of fingers or toes. The significance of the condition depends on whether the extra digit is on the radial (preaxial) or ulnar (postaxial) side of the hand. Preaxial polydactyly is seen in Apert’s syndrome, Fanconi’s syndrome, and Holt- Oram syndrome. Postaxial polydactyly is associated with Ellis-Van Creveld syndrome and Laurence-Moon-Biedl syndrome . Central polydactyly. The diagnosis of polydactyly is evident clinically and can occur as an isolated entity unassociated with any syndromes

66. The thumb has an additional three phalanx digit arising medial to it consistent with  pre axial polydactyly .

67. Bilateral bifid fifth metacarpals with duplication of the little fingers representing a form of post-axial polydacty .

68. SYNDACTYLY Description. Syndactyly is the most common developmental anomaly of the hand, but it may also affect the foot and manifest in the form of fusion of the skin between the digits (syndactyly) or fusion of the osseous phalanges of adjacent digits (synostosis). It is the result of a defect of mesenchymal organization during the 5th fetal week, resulting in failure of an interphalangeal joint to develope .

69. Clinical Features. The incidence is thought to be 1 in 2500 births, with a distinct male predominance. It may be considered partial when the fusion involves only the proximal segments, or complete if the fusion extends to the distal aspect. If the fusion is distal, with the proximal segments free, the appropriate name is acrosyndactyly .

70. SYNDACTYLY ..

71. POLYSYNDACTYLY. Dorsoplantar Foot. Note the duplication and hypoplasia of the second ray with soft tissue fusion to the great toe.

72. NORMAL VARIANTS ACCESSORY SACROILIAC JOINTS. A. AP Lumbosacral Spine. There are bilateral accessory sacroiliac joints evident between the posterior inferior iliac spine and the posterior aspect of S2 (arrow) and S3 (arrowhead). B. CT Scan. The site of accessory joint formation is evident as being dorsal between the posterior inferior iliac spine and the posterior sacrum (arrow). COMMENT: Accessory sacroiliac joints are present in 10-35% of patients; the incidence increases with age and the joints are rare before the 4th decade. Their contribution to back pain syndromes is unknown, though reported symptoms include back pain, sciatica, muscle spasm, limitation of motion, or tenderness to deep pressure over the accessory joint.

73. ACCESSORY SACRAL FORAMINA. AP Sacrum. There are bilateral geographic defects in the sacral alae representing accessory sacral foramina (arrowheads). B. AP Sacrum. Another example of smaller bilateral accessory sacral foramina (arrows).

74. SACRAL OSSIFICATION DEFECT. A and B. AP Sacrum. There is failure of ossification of the lateral margin of the distal sacral foramina (arrows). This is a growth variant that is of no clinical significance and should not be interpreted as a destructive lesion

75. PARAGLENOID SULCI. A-C. AP Pelvis. Various expressions of the paraglenoid (pre-auricular) sulcus are displayed, ranging in depth, size, and symmetry (arrows). COMMENT: This sulcus transmits the neurovascular bundle of the superior gluteal artery and nerve as well as serving as the insertion for the ventral sacroiliac ligaments. It is a characteristic of the female pelvis and is rare in males. It is occasionally unilateral but is most often found bilaterally.

76. IDIOPATHIC CALCIFIED SACROTUBEROUS LIGAMENTS. AP Pelvis. Calcification of the sacrotuberous ligaments is present bilaterally (arrows). COMMENT: Calcification of the sacrotuberous ligaments may be an isolated idiopathic finding; may occur after trauma; or may be part of more widespread ligamentous ossification, such as in diffuse idiopathic skeletal hyperostosis (DISH) and fluorosis

77. HARRIS GROWTH ARREST LINES. A. AP Knee. B. AP Ankle. Thin transverse radiopaque lines within the long metaphyses are depicted (arrows). COMMENT: These lines are commonly observed findings in asymptomatic individuals. Occasionally severe disease or chemotherapy during bone growth can be responsible for these same changes, which represent a failure to convert calcified cartilage at the zone of provisional calcification to bone in the metaphysis .

78. FEMUR BONE BARS. A. AP Specimen Radiograph. Obliquely orientated thick linear sclerotic lines, which do not contact the inner cortices, are present in the metadiaphysis . B. Transverse-Cut Specimen. The thickened bone bars are demonstrated. COMMENT: Bone bars (reinforcement lines) are different from growth arrest lines: They are found in adults, are thicker and obliquely orientated, do not extend to the inner cortical margins, occur in the diaphysis and metadiaphysis, and are usually unilateral. They do not cause pain, are an acquired phenomenon, are often found in osteoporosis.

79. PATELLAR ACCESSORY OSSIFICATION CENTER. Lateral Knee. There is an accessory ossification center for the inferior pole of the patella. COMMENT: This should not be confused with an avulsion fracture.

80. PSEUDO-CYST. Lateral Calcaneus. A well-circumscribed radiolucency is present in the calcaneus (arrow). COMMENT: This radiolucency is caused by the orientation of the calcaneal trabeculae. Differentiation from simple bone cyst, intra-osseous lipoma, and other benign tumors can be difficult and may require MRI examination. Pseudo-cyst is typically not identifiable on an axial view of the calcaneus, whereas tumors will be seen.

81. CALCANEAL APOPHYSIS. Lateral Calcaneus. The secondary ossification center for the calcaneal apophysis is densely sclerotic (arrows). COMMENT: This is a normal manifestation of the growing calcaneus and often will be multisegmented . The multiserrated margins (arrowheads) of the junction zone with the calcaneal body are also common normal findings . In young patients with pain in the calcaneus these normal features of sclerosis, fragmentation, and junctional irregularity should not be confused with avascular necrosis (Sever’s disease). The film should be bright lighted to examine the soft tissue details of the Achilles insertion and pre-Achilles fat for evidence of edema. Plain film studies of the opposite asymptomatic calcaneus are often helpful.

82. REFERRENCE Yochum & Rowe - Essentials of Skeletal Radiology

83. THANK YOU