what-when-how
In Depth Tutorials and Information
2 mo
4 mo
12 mo
Brtl
WT
Sagittal
Coronal
Sagittal
Coronal
Sagittal
Coronal
FIGURE 38.3
Representative computed tomography (CT) images of knee tissue from Brittle IV (Brtl) and wild-type (WT) mice at ages
2, 4 and 12 months (
n
= 3 Brtl and 3 WT mice per age group). High-resolution CT images of sagittal and coronal sections are shown. By 2
months of age, Brtl mice showed thinning of subchondral bone (SCB) (arrowhead in image of Brtl mouse; arrow in image of WT mouse) and
decreased trabecular bone. At 12 months, Brtl mice demonstrated subchondral sclerosis (arrowheads).
(Reproduced with permission from Arthritis
and Rheumatism.)
CLINICAL STUDIES OF THE
RE
LATIONSHIP OF OI AND
OA
40
35
30
25
20
15
10
5
0
Female
Male
A survey conducted on the Osteogenesis Imperfecta
Foundation's website concluded that adults with mild
(type I) OI have functional impairment secondary to
musculoskeletal concerns.
23
The majority of the adults
who responded to the survey reported that they had
some form of arthritis; OA was the most common diag-
nosis reported by the respondents. Functional impair-
ment was secondary to pain and instability in the large
weight-bearing joints of the lower extremities as well as
ligament and tendon issues (
Figure 38.4
).
There have been several cases reported in the ortho-
pedic literature of hip and knee replacement in patients
with end-stage OA associated with OI. Papagelopoulous
and colleagues described a series of five total hip and
three total knee arthroplasties performed between 1969
and 1990 at the Mayo Clinic.
24
They reported improve-
ment in both pain and function after surgery. Patients
were followed for 7 years post total hip and 10 years fol-
lowing total knee replacement.
Chaus and colleagues also reported successful treat-
ment of end-stage post-traumatic OA treated with total hip
replacement and clinically significant improvement of pain
and quality of life in a 16-year-old patient with type I OI.
25
Recently, Rousseau and colleagues looked at car-
tilage degradation in patients with OI as compared to
subjects with OA and age-matched controls and the
relationship between this and alterations of the mech-
anism of type I collagen.
26
Biochemical markers that
were used to assess changes in bone and cartilage turn-
over were Helix-I and CTX-I for type I collagen for bone
FIGURE 38.4
Impairments due to arthritis in adults with mild
OI.
No assist
indicates that the impairment resulted in no requirement
for any assistance.
Heavy/Light/Personal
indicates that the impair-
ment resulted in the need for assistance with heavy/light/personal
tasks, respectively.
(Reproduced with permission from Osteoporosis
International.)
and CTX-II for cartilage. They measured maturation of
type I collagen using alpha CTX-I/beta CTX-I ratio.
They found that urinary levels of Helix-I and alpha/
beta CTX-I were higher in patients with OI as com-
pared to healthy age-matched controls and urinary
CTX-II levels in patients with OI were similar to older
subjects with knee OA and significantly higher than
age-matched controls and older healthy individuals.
Previous studies have shown increased bone resorption
is associated with increased progression of joint dam-
age in patients with knee OA.
9,12,19
The above human and animal studies demonstrate
that patients with OI have a greater propensity to
develop rapidly progressing OA.
