Slide 077 — Osteogenesis imperfecta OI

Clean FRCS notes with inline figures

Osteogenesis imperfecta OI

•Xray: Trifoil shaped pelvis, protrusio, lateral bowing of R femur shaft.

•Also check/perform check the rest of the lower limbs, expect to see gracile or overtubulated bones, anterior bowing of tibia (Saber shin), lateral bowing and erlenmeyer flask appearance of femur. In the spine, may find codfish vertebrae or kyphoscoliosis. Also need XR skull to see if there is Wormian bone + basilar invagination.

If fracture:

•Hypertrophic tumoral callus

•Malunion

•Pseudoarthrosis

Diagnosis: OI

•Ddx: rickets/ osteomalacia, idiopathic juvenile osteoporosis, NAI, fibrous dysplasia

•(Ddx for children with repeated fracture)

Examination

•Short stature (proportionate)

•Thin skin

•Face

•Eyes: Blue sclera

•Ears: Impaired hearing (in type 1)

•Mouth: Defective detinogenesis. High pitch voice

•Triangular shaped head with broad forehead

Ortho:

•Lateral bowing of femur

•Anterior bowing of tibia (saber shin)

•Genu varum

•Acetabular protrusion

•Kyphoscoliosis

•Congenital radial head dislocation

•Basilar invagination (myelopathy)

•Generalized ligamentous laxity

•Diagnosis is based on radiological and clinical features +/- family history

•Skin Biopsy is gold standard (culturing dermal fibroblasts)

Treatment Goal

•Prevent fracture

•Deformity correction

•Optimize function

•1. Refer to geneticist to establish diagnosis

•2. Medical:

•Bisphosphonates (decrease fracture: 90% increase in cortical diameter, 50% increase in cancellous bone, decrease pain, increase ambulation)

•Growth hormone

•Ca Vit D

•Gene therapy

•3. Ortho

Fracture:

•Normal healing rate, but no remodeling. Also associated with an increased risk of further fracture due to immobilization and/or the stress riser effect at the edges of the cast

•Therefore, if recurrent fracture → I would treat with CR + IMN +/- multiple osteotomies (Sofield-Miller procedure) to correct deformity at the same time

Deformity correction:

•Limbs: Sofield-Miller with telescoping IM system such as Bailey Dubow rod (if medullary canal is wide enough) / Rush pin

•→ Deformity will progress if left untreated due to the HV law leading to selective inhibition of the physeal growth

•Spine: Scoliosis surgery if cobb >45 (no brace due to rib fragility)

•Sofield-Miller: Do osteotomy first and connect with IMN

•Modified Sofield-Miller: Insert IM rod till resistance and osteotomy at that site

Difficulties:

•Anes – malignant hyperthermia, basilar invagination, mitral valve regurg

•Ortho – bleeding, abnormal bone quality, minimal autograft, ligamentous laxity

•Osteogenesis Imperfecta

Rubin classification: Diaphyseal hypoplasia

•Hereditary disease with abnormal Type 1 collagen (quantitative/ qualitative)

•90% have identifiable genetic mutation

•Both quantitative and qualitative defect in COL1A1 and COL1A2 [substitution of glycine by a bulky amino acid e.g. cystine in the procollagen structure, unable to crosslink], leads to reduced collagen secretion and abnormal collagen production → insufficient osteoid production. Unable to remodel normally. But initial fracture healing is normal

•→ affect bone (woven), tendon, ligament, dentin, sclera

Sillience classification

•Type I, milder, AD, most common, blue sclera, abnormal dentinogenesis

•Type II AR die

•Type III AR white sclera, fracture at birth -- > limb deformity, short stature, worst survivable type

•Type IV AD moderate severity, hearing normal, spine deformity, abnormal dentinogenesis

How will you monitor the effect of Bisphosphonate?

•Clinical - pain

XR – vertebral remodeling / Zebra lines

•DEXA – any  total body & LS bone density.

•Serum (ALP, C telopeptide, N telopeptide , TRAP5b) – produced during bone resorption. Osteocalcin – synthesized by osteoblasts to control osteoclasts.

•Urine (deoxypyridinoline) – a collagen breakdown product

•Pros and cons of rush pin vs telescoping rod for deformity correction

•Telescoping rod – can only insert a narrow rod due to narrow canal → increase risk of rod fracture, or trapped rod. Need to change every 4 years

•Rush pin – easy exchange, reduce implant breakage. Change over 2.5 years

#	lvl	marL	indent	logical	original note line
1	0	None	None	0	Osteogenesis imperfecta OI
2	0	None	None	0	Xray: Trifoil shaped pelvis, protrusio, lateral bowing of R femur shaft.
3	0	0	0	0	Also need to check the rest of the lower limbs, expect to see gracile or overtubulated bones, anterior bowing of tibia (Saber shin), lateral bowing and erlenmeyer flask appearance of femur. In the spine, may find codfish vertebrae or kyphoscoliosis. Also need XR skull to see if there is Wormian bone + basilar invagination.
4	0	None	None	0	If fracture:
5	0	171450	-171450	1	Hypertrophic tumoral callus
6	0	171450	-171450	1	Malunion
7	0	171450	-171450	1	Pseudoarthrosis
8	0	None	None	0	Dx: OI
9	0	None	None	0	Ddx: rickets/ osteomalacia, idiopathic juvenile osteoporosis, NAI, fibrous dysplasia
10	0	None	None	0	(Ddx for children with repeated fracture)
11	0	None	None	0	PE:
12	0	None	None	0	Short stature (proportionate)
13	0	None	None	0	Thin skin
14	0	None	None	0	Face
15	0	171450	-171450	1	Eyes: Blue sclera
16	0	171450	-171450	1	Ears: Impaired hearing (in type 1)
17	0	171450	-171450	1	Mouth: Defective detinogenesis. High pitch voice
18	0	171450	-171450	1	Triangular shaped head with broad forehead
19	0	0	0	0	Ortho:
20	0	171450	-171450	1	Lateral bowing of femur
21	0	171450	-171450	1	Anterior bowing of tibia (saber shin)
22	0	171450	-171450	1	Genu varum
23	0	171450	-171450	1	Acetabular protrusion
24	0	171450	-171450	1	Kyphoscoliosis
25	0	171450	-171450	1	Congenital radial head dislocation
26	0	0	0	0	Basilar invagination (myelopathy)
27	0	0	0	0	Generalized ligamentous laxity
28	0	None	None	0	Diagnosis is based on radiological and clinical features +/- family history
29	0	0	0	0	Skin Biopsy is gold standard (culturing dermal fibroblasts)
30	0	0	0	0	Treatment Goal
31	0	228600	-228600	1	Prevent fracture
32	0	228600	-228600	1	Deformity correction
33	0	228600	-228600	1	Optimize function
34	0	0	0	0	1. Refer to geneticist to establish diagnosis
35	0	0	0	0	2. Medical:
36	0	171450	-171450	1	Bisphosphonates (decrease fracture: 90% increase in cortical diameter, 50% increase in cancellous bone, decrease pain, increase ambulation)
37	0	171450	-171450	1	Growth hormone
38	0	171450	-171450	1	Ca Vit D
39	0	171450	-171450	1	Gene therapy
40	0	0	0	0	3. Ortho
41	0	0	0	0	Fracture:
42	0	0	0	0	Normal healing rate, but no remodeling. Also associated with an increased risk of further fracture due to immobilization and/or the stress riser effect at the edges of the cast
43	0	0	0	0	Therefore, if recurrent fracture → I would treat with CR + IMN +/- multiple osteotomies (Sofield-Miller procedure) to correct deformity at the same time
44	0	0	0	0	Deformity correction:
45	0	0	0	0	Limbs: Sofield-Miller with telescoping IM system such as Bailey Dubow rod (if medullary canal is wide enough) / Rush pin
46	0	0	0	0	→ Deformity will progress if left untreated due to the HV law leading to selective inhibition of the physeal growth
47	0	0	0	0	Spine: Scoliosis surgery if cobb >45 (no brace due to rib fragility)
48	0	0	0	0	Sofield-Miller: Do osteotomy first and connect with IMN
49	0	0	0	0	Modified Sofield-Miller: Insert IM rod till resistance and osteotomy at that site
50	0	None	None	0	Difficulties:
51	0	171450	-171450	1	Anes – malignant hyperthermia, basilar invagination, mitral valve regurg
52	0	171450	-171450	1	Ortho – bleeding, abnormal bone quality, minimal autograft, ligamentous laxity
53	0	None	None	0	===================
54	0	None	None	0	Osteogenesis Imperfecta
55	0	None	None	0	Rubin classification: Diaphyseal hypoplasia
56	0	None	None	0	Hereditary disease with abnormal Type 1 collagen (quantitative/ qualitative)
57	0	None	None	0	90% have identifiable genetic mutation
58	0	None	None	0	Both quantitative and qualitative defect in COL1A1 and COL1A2 [substitution of glycine by a bulky amino acid e.g. cystine in the procollagen structure, unable to crosslink], leads to reduced collagen secretion and abnormal collagen production → insufficient osteoid production. Unable to remodel normally. But initial fracture healing is normal
59	0	None	None	0	→ affect bone (woven), tendon, ligament, dentin, sclera
60	0	None	None	0	Sillience classification
61	1	None	None	1	Type I, milder, AD, most common, blue sclera, abnormal dentinogenesis
62	1	None	None	1	Type II AR die
63	1	None	None	1	Type III AR white sclera, fracture at birth -- > limb deformity, short stature, worst survivable type
64	1	None	None	1	Type IV AD moderate severity, hearing normal, spine deformity, abnormal dentinogenesis
65	0	0	0	0	How will you monitor the effect of Bisphosphonate?
66	0	None	None	0	Clinical - pain
67	0	None	None	0	XR – vertebral remodeling / Zebra lines
68	0	None	None	0	DEXA – any  total body & LS bone density.
69	0	None	None	0	Serum (ALP, C telopeptide, N telopeptide , TRAP5b) – produced during bone resorption. Osteocalcin – synthesized by osteoblasts to control osteoclasts.
70	0	None	None	0	Urine (deoxypyridinoline) – a collagen breakdown product
71	0	0	0	0	Pros and cons of rush pin vs telescoping rod for deformity correction
72	0	0	0	0	Telescoping rod – can only insert a narrow rod due to narrow canal → increase risk of rod fracture, or trapped rod. Need to change every 4 years
73	0	0	0	0	Rush pin – easy exchange, reduce implant breakage. Change over 2.5 years

077. Osteogenesis imperfecta OI

Clean FRCS notes with inline figures

Osteogenesis imperfecta OI

If fracture:

Diagnosis: OI

Examination

Ortho:

Treatment Goal

Fracture:

Deformity correction:

Difficulties:

Rubin classification: Diaphyseal hypoplasia

Sillience classification

How will you monitor the effect of Bisphosphonate?

XR – vertebral remodeling / Zebra lines

Direct Q&A

Short stature (proportionate)

Prevent fracture

Hereditary disease with abnormal Type 1 collagen (quantitative/ qualitative)

Clinical - pain

DEXA – any  total body & LS bone density.

Raw speaker-note hierarchy audit

Improved semantic hierarchy used for the study notes

#	semantic level	section?	rewritten line
1	0		Osteogenesis imperfecta OI
2	1		Xray: Trifoil shaped pelvis, protrusio, lateral bowing of R femur shaft.
3	1		Also check/perform check the rest of the lower limbs, expect to see gracile or overtubulated bones, anterior bowing of tibia (Saber shin), lateral bowing and erlenmeyer flask appearance of femur. In the spine, may find codfish vertebrae or kyphoscoliosis. Also need XR skull to see if there is Wormian bone + basilar invagination.
4	0	yes	If fracture:
5	1		Hypertrophic tumoral callus
6	1		Malunion
7	1		Pseudoarthrosis
8	0	yes	Diagnosis: OI
9	1		Ddx: rickets/ osteomalacia, idiopathic juvenile osteoporosis, NAI, fibrous dysplasia
10	1		(Ddx for children with repeated fracture)
11	0	yes	Examination
12	1		Short stature (proportionate)
13	1		Thin skin
14	1		Face
15	1		Eyes: Blue sclera
16	1		Ears: Impaired hearing (in type 1)
17	1		Mouth: Defective detinogenesis. High pitch voice
18	1		Triangular shaped head with broad forehead
19	0	yes	Ortho:
20	1		Lateral bowing of femur
21	1		Anterior bowing of tibia (saber shin)
22	1		Genu varum
23	1		Acetabular protrusion
24	1		Kyphoscoliosis
25	1		Congenital radial head dislocation
26	1		Basilar invagination (myelopathy)
27	1		Generalized ligamentous laxity
28	1		Diagnosis is based on radiological and clinical features +/- family history
29	1		Skin Biopsy is gold standard (culturing dermal fibroblasts)
30	0	yes	Treatment Goal
31	1		Prevent fracture
32	1		Deformity correction
33	1		Optimize function
34	1		1. Refer to geneticist to establish diagnosis
35	1		2. Medical:
36	1		Bisphosphonates (decrease fracture: 90% increase in cortical diameter, 50% increase in cancellous bone, decrease pain, increase ambulation)
37	1		Growth hormone
38	1		Ca Vit D
39	1		Gene therapy
40	1		3. Ortho
41	0	yes	Fracture:
42	1		Normal healing rate, but no remodeling. Also associated with an increased risk of further fracture due to immobilization and/or the stress riser effect at the edges of the cast
43	1		Therefore, if recurrent fracture → I would treat with CR + IMN +/- multiple osteotomies (Sofield-Miller procedure) to correct deformity at the same time
44	0	yes	Deformity correction:
45	1		Limbs: Sofield-Miller with telescoping IM system such as Bailey Dubow rod (if medullary canal is wide enough) / Rush pin
46	1		→ Deformity will progress if left untreated due to the HV law leading to selective inhibition of the physeal growth
47	1		Spine: Scoliosis surgery if cobb >45 (no brace due to rib fragility)
48	1		Sofield-Miller: Do osteotomy first and connect with IMN
49	1		Modified Sofield-Miller: Insert IM rod till resistance and osteotomy at that site
50	0	yes	Difficulties:
51	1		Anes – malignant hyperthermia, basilar invagination, mitral valve regurg
52	1		Ortho – bleeding, abnormal bone quality, minimal autograft, ligamentous laxity
53	0		——
54	1		Osteogenesis Imperfecta
55	0	yes	Rubin classification: Diaphyseal hypoplasia
56	1		Hereditary disease with abnormal Type 1 collagen (quantitative/ qualitative)
57	1		90% have identifiable genetic mutation
58	1		Both quantitative and qualitative defect in COL1A1 and COL1A2 [substitution of glycine by a bulky amino acid e.g. cystine in the procollagen structure, unable to crosslink], leads to reduced collagen secretion and abnormal collagen production → insufficient osteoid production. Unable to remodel normally. But initial fracture healing is normal
59	1		→ affect bone (woven), tendon, ligament, dentin, sclera
60	0	yes	Sillience classification
61	1		Type I, milder, AD, most common, blue sclera, abnormal dentinogenesis
62	1		Type II AR die
63	1		Type III AR white sclera, fracture at birth -- > limb deformity, short stature, worst survivable type
64	1		Type IV AD moderate severity, hearing normal, spine deformity, abnormal dentinogenesis
65	0	yes	How will you monitor the effect of Bisphosphonate?
66	1		Clinical - pain
67	0	yes	XR – vertebral remodeling / Zebra lines
68	1		DEXA – any  total body & LS bone density.
69	1		Serum (ALP, C telopeptide, N telopeptide , TRAP5b) – produced during bone resorption. Osteocalcin – synthesized by osteoblasts to control osteoclasts.
70	1		Urine (deoxypyridinoline) – a collagen breakdown product
71	1		Pros and cons of rush pin vs telescoping rod for deformity correction
72	1		Telescoping rod – can only insert a narrow rod due to narrow canal → increase risk of rod fracture, or trapped rod. Need to change every 4 years
73	1		Rush pin – easy exchange, reduce implant breakage. Change over 2.5 years