Pediatric Bony Stress Injuries. SP Karakas, E Park, S Morrison Cleveland Clinic Children s Hospital

Transcription

1 Pediatric Bony Stress Injuries SP Karakas, E Park, S Morrison Cleveland Clinic Children s Hospital

2 Pediatric Bony Stress Injuries Overview This presentation is focused on overuse injuries of healthy bones in pediatric patients and demonstrates variety of examples

3 Pediatric Bony Stress Injuries Overview Competitive sports are practiced more than ever in the pediatric age group resulting in increased incidence of acute and overuse musculoskeletal injuries

4 Pediatric Bony Stress Injuries Mechanism Stress injuries are a spectrum, beginning with stress reaction (stress response) that eventually leads to stress fracture

5 Pediatric Bony Stress Injuries Pathophysiology Repetitive stress Cellular stress with increased blood flow which can be detected on MRI as increased T2 signal Osteoclasts absorb lamellar bone and create microscopic resorption cavities Muscles and tendons hypertrophy Stress will be transmitted to the periosteum Periostitis During remodeling resorption cavities will be filled up with lamellated bone Imbalance between the remodeling and resorption result in fractures at the point exposed to the stress

6 Question Please select True or False for the statement below T / F: Most stress fractures occur six months after a new exercise

7 Answer Answer: False Alteration in the training program is the most significant factor producing the injury and most stress fractures occur 4 to 5 weeks after the onset of a new exercise.

8 Pediatric Bony Stress Injuries Symptoms Overview Acute state Localized pain that is not present at the start but occurs after or toward the end of physical activity Subacute state Pain that occurs earlier during the physical activity and lingers longer Late state Pain persists throughout the training and during daily ambulation

9 Pediatric Bony Stress Injuries Imaging Overview Radiographs: Not sensitive in early period, show abnormalities 2 to 8 weeks after start of the symptoms MRI: Very sensitive exam to the earliest changes of the bone Nuclear Medicine Bone Scan: Very sensitive exam to the earliest changes of the bone, but has no anatomical detail CT: Reserved for defining the details of complex bony injuries

10 Pediatric Bony Stress Injuries Radiographs There is usually an area of sclerosis oriented linearly A focal periosteal reaction or a cortical break may be present

11 Pediatric Bony Stress Injuries MRI Surface or extremity coils should be used T1 images generally are best for demonstrating normal anatomy Proton density, T2 fast spin echo and STIR (Short TI Inversion Recovery) sequences are best for pathology detection

12 Pediatric Bony Stress Injuries MRI Marked edema-like increased T2 signal intensity in the bone marrow Transverse, T1 and T2 low-signal-intensity fracture line Cortical increased signal and periosteal reaction

13 Pediatric Bony Stress Injuries Treatment Conservative therapy Reduction / limitation of weight-bearing Immobilization if there is noncompliance to treatment Adequate duration of therapy until an asymptomatic state is reached with gradual exposure to stress Individually tailored rehabilitation program

14 Upper Extremity

15 Case 1 11 year old female with chronic and intermittent pain in her right shoulder She has a twitching tic to her right shoulder: she elevates her shoulder, rotates her head, and extends her neck back that way

16 Please click on the abnormality on the following radiograph

17 Skip to answer

18 No, that is not right. Please try again.

19 That is right! Early fracture Healing fracture 6/19/ /10/2007

20 First Rib Stress Fracture Most common in throwing athletes, who perform repetitive overhead activities and in heavy backpack carriers Occur at the subclavian artery groove along the anterior aspect of the first rib due to opposing and repetitive downward forces from the intercostal and serratus anterior muscles and upward forces from the anterior scalene muscle

21 Case 2 14-year-old male, freshman wrestler He denies any one particular injury to the left shoulder, but he has had gradual onset of pain over the last 3 weeks He has pain with overhead activities and reaching behind his shoulder He has some tenderness of the left AC joint and acromion diffusely

22 No abnormality is seen

23 Following two months of rest and conservative management, patient has had some persistent pain in the left shoulder MRI was obtained Please click on the abnormality on the following MRI image

24 Skip to answer

26 That is right! Increased T2 signal within the acromial ossification center, consistent with edema

27 Acromion Stress Fracture Rare Usually in young to middle aged patients Associated with a single violent muscle contraction or repetitive subcritical load to the shoulder

28 Case 3 14 year old baseball pitcher complained of pain in shoulder of his throwing right arm

29 Please click on the abnormality on the following radiograph

30 Skip to answer

32 That is right! Widening and irregularity of the growth plate Normal side

33 Widening of the growth plate, edema in the epiphysis and metaphysis together with periosteal edema T1 Coronal T1 Sagittal

34 Little League Shoulder Contralateral film of other shoulder may be helpful for comparison MRI not always necessary but may be helpful in uncertain cases True stress fracture or inflammatory reaction of the growth plate is unknown Similar changes described in other overhead sports (e.g. cricket bowler) Treatment is conservative

35 Case 4 16-year-old male wrestler complains of bilateral posterior elbow pain For the last 4 weeks he has been noticing pain with weight training including bench press, military press, and particularly triceps extensions

36 Please click on the abnormality on the following radiographs

37 Skip to answer

39 OF That is right! Widened growth plate with sclerotic edges

40 Irregular, widened growth plate with increased T2 signal intensity RT STIR SAG LT

41 Olecranon Stress Injury The olecranon epiphysis appears in boys at 9-11 years of age and normally closes between years Stress fractures of the olecranon growth plate are Salter type 1 injury There can be fragmentation of the olecranon epiphysis

42 Case 5 15-year-old high school athlete, running back, strong safety and pitcher comes in with complaints of right elbow pain for 3 months Denies any significant injury but does do a lot of arm tackling as a strong safety Since that time he has had pretty mild pain on and off in his elbow He has a difficult time extending his elbow

44 Skip to answer

46 That is right! Focal lucency is seen within the capitellum near the articular surface

47 MRI was obtained two weeks later

48 Coronal GRE Coronal PD Fat Sat Anterior capitellar cortical irregularities

49 Sag PD Fat Sat Sag GRE Tiny bony fragment is present within the joint space

50 Capitellar Osteochondritis Dessicans (OCD) Overuse and resultant chronic lateral impaction may lead to OCD of anterior capitellum or radial head Most commonly in adolescent pitchers or gymnasts (ages 12-16) Loose body formation and necrosis of the bone followed by a healing response and reossification may lead to residual deformity and arthrosis

51 Case 6 12 year old baseball pitcher Pain in right elbow for the past three months

52 Lt RT LT *

53 Panner s Disease (Osteochondrosis of capitellum) Occurs in childhood (age 5-11) as opposed to osteochondritis dissecans which occurs in adolescence Patients may recover with little or no deformity Articular surface typically remains intact and does not undergo fragmentation

54 Case 7 12 year old gymnast has noted gradual onset of wrist pain and tenderness Worsening pain on the high bar and hanging from the rings

56 LT LT RT RT Skip to answer

57 LT LT RT RT No, that is not right. Please try again.

58 That is right! LT LT RT RT Widening of growth plate with some metaphyseal irregularity

59 Broadened irregular physis COR GRADIENT ECHO CARTILAGE COR T1

60 Physeal cartilage may herniate into the metaphysis

61 Gymnast Wrist Joint capsule and ligaments 2-5 times stronger than growth plate Not to be confused with rickets May result in increase ulna plus variance in gymnasts Ulna physis usually spared but similar findings in ulna physis described in adolescent breakdancer!

62 Lower Extremity

63 Case 8 13 year old 8th grade athlete who plays softball, volleyball and basketball 3 month complaint of snapping on the lateral aspect of her left hip, aggravated in the past 2 weeks by a more severe sharp pain in the groin

65 MRI was obtained two days later Please click on the abnormality on the following MRI images

66 AX T2 FAT SAT Skip to answer COR STIR COR PD FAT SAT

67 AX T2 FAT SAT No, that is not right. Please try again. COR STIR COR PD FAT SAT

68 That is right! AX T2 FAT SAT Focal area of abnormally high T2 signal in the marrow of the left superior ramus immediately adjacent to the pubic symphysis COR STIR COR PD FAT SAT

69 Pubic Bone Stress Injury Includes inferior pubic rami stress fractures and osteitis pubis Jumping, twisting or turning motions during sprinting, cutting and kicking activities Most common among soccer players, presents with groin pain Maybe unilateral or bilateral Bone marrrow edema most commonly seen on MRI

70 Case 9 16 year old active football player presents with pain in left hip for the last three months States no acute injury Pain is worse with training

72 Skip to answer

74 That is right! Ill-defined lesion within the left lateral ischial tuberosity with features of both mixed lytic and sclerotic densities

75 MRI was obtained for further evaluation of the left ischial lesion

76 COR STIR COR T1 Heterogeneous T2 hyper and T1 hypo signal intensity with areas of preserved fatty marrow at the site of the hamstring insertion with mild thickening of the hamstring tendons (not shown)

77 AX T2 FAT SAT Separation and curvilinear increased signal at the ischial tuberosity apophysis at the attachment site of the hamstring tendons suggesting an avulsion injury AX T1

78 Chronic Hamstring Avulsion Injury Hamstring tendon origin at the ischium is a frequent site of tendinosis, tears and bony avulsions in high-level atheletes Usually indirect trauma In the event of blunt direct trauma, a muscle contusion, intramuscular hematoma, myositis ossificans, or compartment syndrome may develop

79 Another case showing chronic avulsive injury with myositis ossificans

80 Case 10 6 year old otherwise healthy young male had developed left hip pain over the last several weeks It hurts with activities and gets better with rest Aching in the groin and causes him issues with activities

82 An MRI was obtained three weeks following failed conservative treatment with rest Please click on the abnormality on the following MRI images

83 Coronal STIR Skip to answer

85 That is right! There is marrow edema surrounding a linear hypointense signal related to stress fracture at the left femoral neck

86 Femoral Neck Stress Fractures (Compression type) Compression type stress fractures are most common in younger patients They are usually limited to the medial cortex or extend into the medial medullary cavity These are stable fractures

87 Case year old male basketball player with bilateral knee pain worse on the left He has been having symptoms for a year but his symptoms worsened 3 weeks after his new jumping exercise in basketball practice

89 Skip to answer

91 That is right! Soft tissue swelling Fragmentation

92 Two months after initial radiographs MRI of the knee performed

93 T1 SAG Small, nondisplaced osseous fragment at the inferior pole of the patella without marrow edema within either bone suggesting remote / healed injury T2 FAT SAT SAG Moderate thickening and minimal signal abnormality within the proximal patellar tendon, suggesting chronic tendinosis

94 Sinding-Larsen-Johansson (SLJ) Disease SLJ represents a form of jumper s knee that is exclusive to the adolescent population Traction phenomenon in which repeated strain at the patellar tendon causes chondro-osseous tensile failure This leads to a traction tendinitis with partial tendon avulsion and de novo calcification of the proximal patellar tendon The involved child elicits history of chronic anterior knee pain with running, jumping, climbing stairs

95 Case year old very active female athlete with right shin pain She plays both soccer and basketball Physical exam showed pain with direct palpation along the proximal 1/3 of the right tibia

97 Following unremarkable radiographs of the tibia and fibula MRI of the lower leg obtained

98 STIR COR STIR COR Based on above images is this a stress reaction or a stress fracture? A. Stress reaction B. Stress fracture

99 STIR COR STIR COR No, you are wrong Since there is no definite fracture line this is a stress reaction

100 STIR COR STIR COR You are right! Since there is no definite fracture line this is a stress reaction

101 Images through upper tibia demonstrate abnormal increased marrow and cortical signal intensity with mild surrounding soft tissue edema AX FAT SAT T2

102 Stress Reaction Versus Stress Fracture In stress injuries stress reaction and stress fractures can be differentiated based on the presence of a fracture line which should appear dark on all sequences

103 Question Please select True or False for the statement below T / F: In runners, femoral and tarsal stress fractures occur in older patients, and fibular and tibial stress fractures occur in the younger athlete

104 Answer Answer: True In runners, femoral and tarsal stress fractures occur in older patients, and fibular and tibial stress fractures occur in the younger athlete

105 Factors Associated With Running Related Stress Fractures: Training errors Running surfaces Shoes Diet factors: malnutrition, anorexia nervosa Smoking Alcohol use Hormonal alterations: amenorrhea Inhaled corticosteroids Hypothalamic dysfunction

106 Case year-old male with left lower leg pain He ran a time trial for cross country and developed significant discomfort diffusely through the left lower leg and to a lesser extent about the anterior aspect of the right lower leg on the following day He is exquisitely tender on the posterior aspect of the proximal third of the left tibia

107 His initial x-rays were normal These followed with MRI exam of his lower legs

108 Fracture line is clearly seen on these coronal STIR images as a linear hypointensity thorough intensely bright abnormal marrow signal together with surrounding soft tissue edema

109 One month later, follow up radiographs showed mature callus formation and sclerosis at the healing fracture site

110 Question Please select True or False for the statement below T / F: In 75% of tibial stress fractures the medial tibia is involved

111 Answer Answer: True In 75% of tibial stress fractures the medial tibia is involved

112 Case month old child presented with history of limp from parents No known trauma Normal blood count, no fever Tender to palpation over lower tibia

113 Spiral nondisplaced fracture at the junction of the middle and distal thirds of the right tibia with periosteal new bone formation

114 Toddler s Fracture Thin oblique tibial shaft fracture often subtle or missed initially Not caused by child abuse Indirect twisting injury when toddler falls Initial injury may not be witnessed or appreciated by parents This is in differential diagnosis of stress fractures that can occur in toddlers

115 Case 15 Adolescent female soccer player complained of chronic pain and stiffness in the ankle worsened with extreme plantar flexion

117 Due to persistent ankle pain MRI of the ankle obtained Please click on the abnormality on the following MRI images

118 Skip to answer

120 That is right! Sagittal T1 Sagittal STIR Tiny posterior ankle joint fluid and marked marrow edema like signal within the os trigonum and dorsum of the talus indicating os trigonum syndrome (posterior ankle impingement syndrome)

121 Os Trigonum Identified in 10% of population When present is bilateral in 50% Joined to posterior talus by fibrous tissue, cartilage or bone

122 Os Trigonum Syndrome Extreme plantar flexion compresses the os trigonum between talus and calcaneus Maybe associated tenosynovitis of Flexor Hallucis Longus Originally described in ballet with full pointe, demipointe, tendu, frappe and relevé positions

123 Case 16 2 year old female presented with left leg limping for about 1 week No injury recalled Physical exam showed swelling of the heel pad and antalgic gait A heel mass such as foreign body granuloma or extra-abdominal desmoid was a concern

124 No abnormality is seen except for slightly swollen appearance of the heel fat pad

125 The patient had an MRI of her foot in the following week Please click on the abnormality on the following MRI images

126 AX T2 FAT SAT AX T1 AX FAT SAT T1 Skip to answer

127 No, that is not right. Please try again. AX T2 FAT SAT AX T1 AX FAT SAT T1

128 AX T2 FAT SAT AX T1 AX FAT SAT T1 The round circle marks bone marrow edema within the calcaneus which enhances on post contrast images Arrows point to the fracture line that is hypointense on all sequences That is right!

129 STIR SAG T1 SAG Bone marrow edema within the calcaneus is again seen with minimal heel pad edema probably occurred due to altered weight bearing

130 * * * X-rays obtained 10 days after the MRI exam show healing stress fracture of the calcaneus as linear area of sclerosis (*)

131 Calcaneus Stress Fracture Initially presents similar to plantar fasciitis with pain in the plantar aspect of the heel swelling and warmth over the calcaneus There is often tenderness along the medial and lateral wall of the calcaneus and along the plantar aspect of the tuberosity X-rays are often unremarkable Bone scan or MRI are generally positive during early presentation

132 Case 17 6 year old female presented with pain and swelling in the left foot She is running on her heels and having more pain with activity Physical exam showed some mild bruising over the lateral aspect of the foot

133 No abnormality identified

134 Since the patient s symptoms persisted a follow up radiographs obtained two weeks later Please click on the abnormality on the following radiographs

135 Skip to answer

137 Diffuse sclerosis in the base of the cuboid is consistent with a stress fracture with healing That is right! Normal cuboid on the right side

138 Diffuse sclerosis in the base of the cuboid bone is consistent with a stress fracture with healing

139 Cuboid Fracture Often missed or not recognized Similar to toddlers fracture and may be very subtle or normal initially Radionuclide bone scan or MRI rarely indicated but abnormal initially Forced plantar flexion compresses the cuboid between calcaneus and metatarsals

140 Case year-old football player, left foot pain intermittently for the past year Describes soreness with running Reports no injury, swelling or discoloration

142 Skip to answer

144 That is right! Healing mid shaft transverse fracture with exuberant bridging callus formation

145 Radiograph obtained 2 months later demonstrates mature callus formation and healing of the fourth metatarsal fracture

146 Metatarsal Stress Injury (i.e. March fracture) Result of chronic stress due to vertical loads Can occur in any sport that has repetitive jumping, landing, and cutting maneuvers Second and third metatarsal most commonly involved Fracture line may not be visible on x-ray for 2-6 weeks from onset of fracture

147 Case year-old female football player complaining of significant right foot pain within the anterior medial planter region

149 Skip to answer

151 That is right! Fragmented and sclerotic lateral sesamoid

152 T2 FAT SAT COR T1 FAT SAT COR Increased T2 and decreased T1 signal with fragmentation of the lateral sesamoid

153 Sesamoid Stress Injury Stress fractures are the most common hallucal sesamoid pathology They may be seen in any athlete whose sport relies heavily on the lower extremities, but they are most frequently found in dancers and runners Sesamoid blood supply is primarily from a proximal and plantar direction and due to lack of secondary blood supply osteonecrosis and nonunion can be seen frequently