Radiological Interpretation of common bone Diseases

This PPT provides a comprehensive overview of common bone and joint diseases with their key radiological features. It includes detailed X-ray, MRI, and CT scan findings that help in better understanding of joint pathology.

Covered Topics:

Ankylosing Spondylitis: sacroiliitis, squaring of vertebrae, bamboo spine, dagger sign, round back deformity, cervical spine fusion.

Osteoarthritis: Kellgren-Lawrence classification, joint space narrowing, subchondral sclerosis, osteophyte formation, tibial spiking, genu varum.

Rheumatoid Arthritis: symmetric polyarthritis, radiographic joint changes, rheumatoid nodules, and characteristic deformities like swan neck, boutonniere, mallet finger, Z deformity, and ulnar deviation and more diseases


Who Should Use This PPT:-
Medical students, Ayurveda scholars, radiologists, and healthcare professionals seeking to strengthen their knowledge of radiological interpretation of joint disorders.

1. Radiological Interpretation of joint orders Dr. Jyoti Rajput 2 nd year PG Scholar Rog Nidan & Vikriti Vigyan Department, Pt.K.L.S.Government Ayurveda Institute,Bhopal ( M.P. )

2. Rheumatoid Arthritis Rheumatoid Arthritis (RA) is a systemic inflammatory disease of unknown etiology that predominantly affects the musculoskeletal system.

3. Radiographic Findings Imaging findings separate the disease into Early Classical Late Stages .

4. Early Stage Periarticular edema Synovial joint distension due to synovitis and joint effusion(indirect sign) Periarticular osteopenia Pannus (hallmark of RA) Causes cartilage loss & bone erosions Pannus means “blanket” and refers to the invasive hyperplastic synovium that develops in RA.

5. Classical Findings As the disease progresses:- 1. Include a combination of cartilage space narrowing, erosions 2. Additional soft tissue thickening in specific joint locations The term cartilage space rather than joint space is used in this text to emphasize that cartilage is responsible for most of the thickness of the space between bony articulations, although joint fluid and synovitis may also contribute to this “space

6. Late Stage Joint derangement mark a progression of these processes from erosions and cartilage loss to ankylosis . Joint subluxation /dislocation Generalized joint destruction. Usually, once the late stages of joint derangement have occurred, the diagnosis of RA is well known.

7. The American College of Rheumatology (ACR) classification criteria for RA Morning stiffness Arthritis of three or more joint areas Arthritis of hand joints (wrist and/or metacarpophalangeal joints) Symmetric arthritis Rheumatoid nodules Serum rheumatoid factor Radiographic erosions typical for RA

8. Early Radiographic Findings in RA PA radiograph of the hand shows 1. soft tissue swelling at the first PIP (arrow) and MCP (oval) joints. 2. Osteopenia is demonstrated by generalized thinning of the bone cortices. 3.There is mild erosion of the ulnar styloid and a small cyst in the radial styloid .

9. Joint Distension A. Normal Suprapatellar Pouch B. Mild Joint Distension C. Moderate Joint Distension A B C

10. Classic Radiographic Findings in RA Hand and wrist pa view Periarticular osteopenia , soft tissue swelling, and bare area erosions at MCP joints (most marked at the ulnar side of the 3rd MCP) 2. Widened scapholunate space with proximal capitate migration ( asterisk ) and narrowing of the scapholunate-capitate joint (SLAC wrist).

11. Arthritic changes in the hip: RA versus OA. RA and OA tend to involve different locations of the hip that may be identified on radiographs. A, Cartilage space narrowing in RA is usually uniform and results in axial migration of the hip (arrow) and medial migration of the femoral head and acetabulum ( acetabular protrusion) with the femoral head located medial to the ilioischial line (arrowheads). A small osteophyte is also present at the superolateral aspect of the femur in A, which is likely related to secondary osteoarthritis. B, Asymmetric cartilage space narrowing in OA with superior articular narrowing (arrow). No acetabular protrusion is present; the femoral head is located lateral to the ilioischial line (arrowheads).

12. Late Radiographic Findings in RA Subluxations from ligament, tendon, and joint capsule laxity become more pronounced and may lead to frank dislocations Fibroosseous fusion of joints ( ankylosis ) is a late complication that may occur after complete cartilage loss. The wrist and midfoot bones are the most common locations for fusion. ankylosis is a more common feature of juvenile RA than adult RA.

13. Another Late consequences Secondary OA in Late RA Persistent use of a joint with the predisposing anatomic abnormalities of RA may cause the joint to develop osteophyte formation, subchondral sclerosis, and subchondral cysts

14. RA with secondary OA and severe uniform cartilage loss. The symmetry of medical and lateral compartment narrowing suggests an underlying inflammatory condition. The changes of OA with osteophytes (arrows) and subchondral sclerosis are noted. Soft tissue swelling and a suprapatellar knee effusion are also present.

15. Radiographic Appearance in Specific Joints HAND View 1. The index and middle finger MCP joints show the earliest features of RA. 2. As the disease progresses, marginal erosions and concentric loss of the joint space develop and may eventually progress to malalignment and joint ankylosis .

16. A. Erosions occurring beneath inflamed tendons B. Due to collapse of osteoporotic bone usually accompanying malalignment A B

17. Some Hand and Wrist Alignment Abnormalities in RA A. Thumb deformities Boutonniere (hitchhiker’s thumb): flexion of the MCP and hyperextension of the IP B. Swan neck deformity Hyperextension of the PIP joint and flexion of the DIP joint A B

18. A. Boutonnie r deformity Flexion of the PIP and hyperextension of the DIP B . Ulnar deviation of the fingers at the MCP joints. May be accompanied by flexion and palmar subluxation of the fingers A B

19. A. Radial deviation of the hand/wrist B. Ulnar translocation of the carpals The proximal row of carpals migrates in an ulnar–palmar direction A B

20. PA view Scapholunate dissociation Separation between the scaphoid (S) and lunate (L)

21. A. Heel changes from RA . 1. Lateral radiograph of the heel demonstrates soft tissue prominence at the pre-Achilles’ bursa and erosions at the subjacent posterosuperior calcaneus , adjacent to tendon insertion (arrows). B. Ankle erosion from RA. 1. Frontal view of the ankle shows characteristic fibular notch erosion at the distal tibiofibular articulation (arrows) A B

22. A. Posterior fat pad sign at the elbow. Lateral view of elbow demonstrates a lucency (arrows) posterior to the distal humerus . This posterior fat pad is revealed because joint effusion or synovial enlargement posteriorly displaces the normally hidden fat in the olecranon fossa , allowing the lucent fat to be visible B. Frontal view Severe cartilage loss is demonstrated by uniform narrowing between the trochlea and proximal ulna. Erosions are present along the ulnohumeral and radiocapitellar articulations.

23. R A involvement of the shoulder. 1.There is uniform loss of the glenohumeral joint space, in keeping with severe cartilage loss. The glenoid is eroded and deformed. 2.Upward subluxation of the humeral head, resulting from chronic rotator cuff tear has allowed pressure erosion of the medial aspect of the proximal humerus . 3.The tip of the distal clavicle is tapered, thinned, and eroded, characteristic of RA. 4. In addition, the undersurface of the distal clavicle is scalloped, likely the result of direct pressure erosion from the superiorly subluxed humeral head.

24. Anterior Atlantoaxial Subluxation in RA Lateral cervical spine (flexion/extension) shows anterior subluxation of C1 on C2 2. Odontoid erosion makes measurement difficult- C2 anterior line used as reference. C1–C2 distance increases in flexion- cord space narrowed in both views. Anterior arch of C1 migrates forward on flexion. 5. Axial and sagittal CT show tapered, eroded dens clearly

25. Hip erosions & synovitis in long-standing RA 25-year RA with acute hip pain. X-ray (A): Erosions at lateral femoral head; metallic BBs mark needle site. Arthrogram (B): Multiple round filling defects → synovial hypertrophy/hyperplasia .

26. Osteoarthritis Also known as osteoarthrosis or degenerative joint disease is a “heterogeneous group of conditions that lead to joint symptoms and signs, which are associated with defective integrity of articular cartilage. In addition to related changes in the underlying bone at the joint margins. The changes of OA in a joint are Asymmetric

27. General Imaging Features Kellgren & Lawrence grading system (used system for grading osteoarthritis) 1. The formation of osteophytes on the joint margins or, in the case of the knee joint, on the tibial spines. 2. Periarticular ossicles ; these were found chiefly in relation to the distal and proximal interphalangeal joints. 3. Narrowing of the joint cartilage associated with sclerosis of subchondral bone. 4. Small pseudocystic areas with sclerotic walls situated usually in the subchondral bones, particularly in the head of the femur.

28. Grades of OA were described as follows:- GRADE Kellgren & Lawrence grading NONE A definite absence of the changes of OA 1 DOUBTFUL 2 MINIMAL A definitely present but of minimal severity 3 MODERATE 4 SEVERE

29. Periarticular ossicles - these were found chiefly in relation to the distal and proximal interphalangeal joints OA of the DIP joint. This PA radiograph of the index finger

30. The formation of osteophytes on the joint margins

31. Narrowing of the joint cartilage associated with sclerosis of subchondral bone

32. Small pseudocystic areas

33. Magnetic Resonance Imaging Virtually all the structures of a joint are involved in OA, and MRI is capable of delineating the morphology and to some degree the integrity of these tissues

34. A, Changes of OA on MRI. The T1-weighted coronal image of the knee shows marginal osteophytes (white arrow) and sharpening of the tibial spines. The medial subchondral bone shows areas of replacement of marrow fat by intermediate signal (black arrows) B , STIR image at another level shows high signal, termed edema -like marrow signal, in the abnormal areas seen in A. 2. Tiny, well-defined fluid signal regions within these larger areas are consistent with subchondral cysts (one marked with arrow).

35. MR arthrography of knee:Coronal image (A): Smooth cartilage in medial femoral condyle & tibial plateau vs. irregular fissuring/thinning of lateral cartilage (arrows). Medial compartment widened due to ligament laxity. Medial meniscus small → consistent with tear

36. Coronal image further anteriorly shows a focal 50% thinning of the medial femoral cartilage (arrows )

37. An axial view of the patellofemoral joint shows fissuring of the patellar cartilage (arrows). 2. The bright joint effusion (due to the contrast injection, E) is noted.

38. Deformity HEBERDENS NODE BOUCHARDS NODE

39. Malalignment & Deformity ( genu varum )-Bow legs

40. Ankylosing Spondylitis AS is the most common inflammatory spondyloarthropathy . These diseases are characterized by sacroiliitis with or without spondylitis , peripheral joint oligoarthritis , enthesitis , dactylitis , and inflammation of nonarticular structures (e.g., skin, gastrointestinal [GI] tract, eye, and heart) Patients with AS usually present with back pain and stiffness in adolescence or early adult life Men are two to three times more commonly affected than women Seronegative spondyloarthropathies include AS, IBD, reactive arthritis, psoriatic spondylitis , and undifferentiated spondyloarthropathy .

41. The imaging hallmark of AS is sacroiliitis Bilateral symmetric sacroiliitis is characteristic of AS but not specific .

42. Grading of 0 to 4 Sacroiliac joint on X-ray Grade Features Grade 0 Normal Grade 1 Suspicious Changes Grade 2 Minimal Definite Changes Grade 3 Distinctive Changes Garde 4 Ankylosis (Fusion Of Bones)

43. Imaging Findings of AS A, Osteitis pubis with grade I sacroiliitis 1.Pubic symphysis : marked subchondral sclerosis & erosions. 2. Right SI joint: subtle sclerosis & poorly defined margins (arrow). B Axial CT of the SI joints. Asymmetric sacroiliitis is present with subchondral sclerosis and erosions normal axial CT image of the SI joints

44. A, Grade II sacroiliitis : 1.Right SI joint: subchondral iliac sclerosis with subtle erosions (arrows). 2.Left SI joint: anterior margin poorly defined (open arrow) B, The normal appearance of the SI joints is shown for comparison.

45. A, Grade III sacroiliitis (AS): Sclerosis of iliac & sacral sides. Left SI: distinct erosions, widened joint space. Right SI: ill-defined margins, partial inferior fusion. B, Grade III sacroiliitis (CT) SI joint space narrowing with partial bony ankylosis on right (arrows ). A B

46. Grade IV sacroiliitis . Ankylosis of both SI joints is present

47. Imaging Findings of AS A, Romanus lesion: Erosions at anterior vertebral margins ( discovertebral junctions). Early feature of ankylosing spondylitis (AS). B, Shiny corners: 1.Sclerosis at vertebral margins (superior/inferior) on lateral radiograph. 2. Due to reactive bone formation at prior Romanus lesion sites. A B

48. A, Squaring: Corner erosion → straight anterior vertebral contour B, Syndesmophyte : Bony bridge from one vertebral margin to the next A B

49. Bamboo spine Vertebral fusion with syndesmophytes leads to an undulating vertebral contour

50. A, Pseudarthrosis : Severe discovertebral destruction with disruption of fused posterior elements. B, “Trolley track” sign: Three parallel radiodense bands on frontal X-ray from fusion of apophyseal joint capsules, interspinous & supraspinous ligaments. A B

51. A, Dagger” sign: Central radiodense line on frontal X-ray from fused spinous processes/ligaments B, Enthesopathy New bone formation at sites of ligament or tendon insertion on bone A B

52. Differentiate Advanced AS: SI joint ankylosis . Syndesmophytes along thoracolumbar spine (arrowheads). Interspinous ligament ossification → “dagger sign” (open arrow). Apophyseal joint capsule fusion → “trolley-track sign” (arrows).

53. Avascular Necrosis Avascular necrosis (AVN) is also known as ischemic necrosis, osteonecrosis , or aseptic necrosis. All these terms refer to bone death resulting from insufficient blood supply to the subchondral bone. The term infarction is usually applied to the identical changes occurring in the marrow cavity rather than in the subchondral bone. Osteonecrosis is the underlying reason for 5% to 12% of total hip replacements .

54. Causes In one large series, 90% of cases occurred in patients who were alcohol abusers or were on corticosteroids. Other etiologies of osteonecrosis include hemoglobinopathies “ The minimum dose of corticosteroids necessary to result in osteonecrosis is thought to be equivalent to 4000 mg for a period of 3 months, although this complication has been reported with even low-dose, short courses of treatment ”.

55. Bone Infarction and Ischemic Bone infarcts (black arrow) and ischemic necrosis (white arrow) of the knee in a patient with systemic lupus erythematosus . Note that the findings are the same but the location is the basis for distinction. A subchondral fracture is present in the medial tibia.

56. Staging of AVN Based on Radiographs Ficat and Arlet on MRI Stage Feature Stage 0 Pre- clinical Stage 1 Pain , normal radiographs Stage 2 Abnormal radiographs; no subchondral collapse Stage 3 Subchondral collapse Stage 4 Degenerative joint disease

57. STAGE FEATURES Stage 0 Imaging negative, biopsy positive Stage 1 Normal radiographs, abnormal MRI or bone scan Stage 2 Abnormal radiographs, intact femoral head Stage 3 Crescent sign Stage 4 Flattening of the femoral head, degenerative joint disease International Classification

58. Steinberg classification STAGE FEATURES Stage 0 Normal or nondiagnostic radiograph, bone scan Stage 1 Normal radiograph; abnormal bone scan Stage 2 Cystic or sclerotic changes on radiograph Stage 3 Crescent sign Stage 4 Flattening of the femoral head Stage 5 Cartilage space narrowing with or without acetabular involvement Stage 6 Advanced degenerative changes

59. A, NORMAL B, ABNORMAL MRI A B

60. A, cystic changes B,Crescent sign A B

61. flattening osteoarthritis

62. In 50% to 80% of patients, both hips are involved although typically the findings are asymmetric Patient with bilateral AVN of the hips with low signal margin (arrow) surrounding central area of fat (asterisk).

63. Imaging Features Five highly specific criteria for the diagnosis of AVN: Collapse of the femoral head with an intact acetabulum and joint space A femoral head lesion with a sclerotic margin in an otherwise normal femur “Cold and hot” appearance on bone scan Low signal margin to the lesion on t1-weighted mr images Positive biopsy

64. “DOUBLE LINE” SIGN (This “reactive zone” likely represents a combination of granulation tissue and chemical shift artifact and is characteristic of ischemic necrosis of the hip)

65. Gout Characterised by a pathological reaction to monosodium urate monohydrate crystals by the joint or periarticular tissues. Increases with age and serum uric acid levels, although only a fraction of patients with hyperuricaemia will develop gout.

66. Radiological features Acute attack:- usually normal or soft-tissue swelling ± effusion Bilateral olecranon bursae effusions Chronic gout (6–12 yrs after onset):- Eccentric peri-articular “punched-out” erosions Uniform joint-space narrowing OA-like changes Calcified tophi around distal phalanges Chondrocalcinosis (e.g. menisci) → secondary OA Bone density:- usually normal (↓ only if severe restriction from pain)

67. A, Juxta-articular erosions seen at the DIP Js B , Gout Punched-out juxta-articular erosions at DIP joint (middle finger). Soft tissue swelling over PIP joints (little & middle fingers) → early tophi . A B

68. Degenerative Disc Disease The intervertebral disc is a composite structure consisting of three distinct components: Annulus fibrosus Nucleus pulposus Cartilaginous endplates

69. Degenerative conditions:- Osteoarthritis: degeneration of synovial joints. Degenerative disk disease: degeneration of intervertebral disks. Spondylosis deformans : spine degeneration with annulus involvement, anterior/lateral osteophytes , and preserved or mildly reduced disk height .

70. A, NORMAL CERVICAL MRI B, NORMAL THORACIC MRI C, NORMAL LUMBAR MRI

71. Lumbar Spine Disk Contour Abnormalities Bulging disk:- 1. Outer annulus extends >50% (180°) of disk circumference. 2 . Usually <3 mm beyond vertebral body edges.

72. Normal Lumbar Contour Normal: Axial T2-weighted image shows a concave posterior margin (arrowhead)

73. Cont ... Disk bulge (MRI):- Axial T2 image shows >180° generalized disk displacement with convex posterior margin (arrowheads).

74. Herniation Disc

75. Disk protrusion:- 1.Herniation with broad base wider than its depth. 2. Nucleus pulposus extends through partial annular defect but remains contained by outer annulus & posterior longitudinal ligament .

76. Disk extrusion:- 1.Herniation with base narrower than herniation depth. 2.Nucleus pulposus extends through complete annular defect

77. Thoracic disk herniation : 1.Sagittal T2 (A): abnormal disk contour (arrow). 2.Axial T2 (B): confirms extruded herniation

78. Sequestered disk:- Extruded disk fragment displaced beyond annulus with no continuity to parent disk.

79. Diffuse Idiopathic Skeletal Hyperostosis [DISH] DISH is characterized by flowing ossification along four or more contiguous vertebrae with normal disk spaces and sacroiliac joints.

80. DISH ( Paravertebral ossification): 1.Lateral cervical X-ray: contiguous anterior longitudinal ligament ossification (C4–C7, white arrow) + posterior longitudinal ligament ossification (black arrow). 2. Upper pharynx displaced by C1–C2 ossification → swallowing difficulty.

81. DISH (thoracic spine):- 1. Lateral X-ray: contiguous anterior longitudinal ligament ossification across ≥4 segments (arrowheads), classic appearance .

82. Spinal Stenosis Lumbar DDD staging: 1. Commonly reported as minimal, moderate, or severe. 2. Based on degree of canal compromise from disk displacement or stenosis . .

83. Cervical spinal stenosis (moderate):- 1. Axial T2: disk osteophyte complex contacts spinal cord (arrow) → mild cord flattening, reduced CSF space .

84. Lumbar spinal stenosis (severe): Axial T2: facet joint OA (arrows) + moderate disk bulge (arrowheads) → severe central stenosis with CSF effacement around traversing nerves.

85. Cervical foraminal stenosis:axial T2 (A): hypointense disk- osteophyte complex from uncovertebral hypertrophy (arrow).Oblique x-ray (B): uncovertebral hypertrophy (arrow) causing foraminal stenosis , matching MRI.

86. Modic type 1 change: Sagittal T1 (A) & T2 (B):- 1.disk height loss + desiccation.L3–4: endplate signal alteration, T1 hypointense & T2 hyperintense (arrows).)

87. Modic type 2 change:Sagittal T1 (A) & T2 (B): Disk desiccation at multiple levels.L5–S1: endplate signal abnormality (arrows), fat signal pattern → hyperintense on T1 & T2, suppresses with fat suppression.

88. Type 3 Modic change: Sagittal T1 and T2 MR images show degenerative disc disease at the lumbosacral junction with a well-defined hypointense area at the anteroinferior L5 end plate.

89. 1. A,T1 image normal 2. B,T2 image shows posterior annular fissure as a small hyperintense focus. A B

90. Spondylolisthesis Forward slip of one vertebra over another, commonly L4–L5 or L5–S1. Types: Isthmic (50%) – pars defect ( spondylolysis ), posterior elements left behind. Degenerative (25%) – usually L4–L5. Dysplastic (20%) – congenital facet anomaly, often with spina bifida occulta . Others – post-traumatic, pathological ( tumor /TB), iatrogenic (post-surgery)

91. Meyerding Classification   The grades are defined as:  Grade I (0-25% slip) Grade II (26-50% slip) Grade III (51-75% slip) Grade IV (76-100% slip) Grade V (greater than 100% slip, also called spondyloptosis )

92. 1 Stage 2 stage 4 stage 3 stage

93. Spondylolysis A defect in the pars interarticularis (between superior and inferior articular facets), usually in the lumbar spine

94. Radiographics Feature Plain radiograph limited sensitivity compared to SPECT and CT  Scottie dog sign inverted Napoleon hat sign CT wide-canal sign  may be present on sagittal reformats when there is spondylolisthesis   deviation of the spinous process sclerosis of the contralateral pedicle Darth Vader sign  on axial slices

95. MRI Unilateral Or Bilateral Bone Marrow Edema Signal As A Sign Of  Stress Response Fractures Lines May Be Visible Depending On Sequence Used

96. Scottie Dog Sign

97. A, BILATERAL L5 PARS FRACTURE B, BILATERAL L5 PARS DEFECT C, BILATERAL L5 PARS WITH SPONDYLOLISTHESIS A B C

98. Pedicle Stress Fracture Inverted Napoleon Hat Sign