Kozo Furushima, MD ･ PhD. Hiroshi Kusano , MD
Yoshiyasu Itoh, MD ･ PhD.
Keiyu Orthopaedic Hospital, Tatebayashi, JAPAN
Keiyu Orthopaedic Hospital
JAPAN
Kozo Furushima
Introduction
 Many baseball players with UCL injuries have persistent
fragments due to throwing disorders in their youth.
 It is not yet clear whether a ligament with fragments is
more fragile than a normal ligament in baseball players.
Keiyu Orthopaedic Hospital, JAPAN
Purpose
 This study compared three types (fragment,
malunion, and normal) of throwing-related UCL
injuries and prospectively examined the risk ratio
that a player could no longer pitch.
Keiyu Orthopaedic Hospital, JAPAN
Subjects
439 baseball players diagnosed with UCL injuries
From Nov. 2009 to Jun. 2013 (43 months)
 Each patient’s ability to return to the competitive baseball was
assessed after at least 3 months of systematic rehabilitation.
 Exclusion from this study
Subjects who failed to comply with rehabilitation, played only
recreationally, or with problems other than the elbow were excluded.
 220 cases were left for analysis.
Keiyu Orthopaedic Hospital, JAPAN
Rehabilitation
• Stretch (scapula, shoulder, hip, etc.)
• Strength training (core, lower and upper extremity)
• Modification of throwing
Rehabilitation was conducted by four physical therapists with at least 5 years of
experience in the treatment of baseball-related elbow and shoulder disorders.
Keiyu Orthopaedic Hospital, JAPAN
Comparison study
This report
 Age: 14-30 y (average, 17.5 y)
 Position: pitcher; 134 catcher; 29 field; 57
 Fragment (X-ray)
 Ligament injury (MR image)
 Statistics: Chi-square test, SPSS v.20.0
Receiver Operating Characteristic curve
Keiyu Orthopaedic Hospital, JAPAN
Images（X-ray）
 The shape of medial epicondyle was assessed in plain
frontal radiographs with the elbow flexed at 45°.
3 groups
 persistent fragments (Fragment)
 complete union following avulsion fracture (Malunion)
 no history of avulsion fracture (Normal)
Keiyu Orthopaedic Hospital, JAPAN
Images（MRI）
 MRI
AOL３slice
Mild injury
SATOU YASUHIKO
Severe injury
Normal
 MR images consisted of three slices along the long axis of the
anterior oblique ligament (AOL).
 These images were used to classify injuries as severe or mild.
Keiyu Orthopaedic Hospital, JAPAN
Results
220 baseball players
Conway-Jobe rating after conservative therapy
 Excellent or Good : Return
 Fair and Poor :
Failure
Mean age Pitcher Catcher
Field
N
Return
16.0 y※
62
18
27
107
Failure
18.9 y※
72
11
30
113
※ p<0.01
N.P
Keiyu Orthopaedic Hospital, JAPAN
Results
Age
≧17 y ＜17 y
Return
28
79
Failure
71
42
Receiver Operating Characteristic curve
Cut-off ：17 y
※ p<0.01
Malunion （×normal）
Fragment （×normal）
Severe injury
Odds
-
3.13
9.20
χ2
p≧0.05
p<0.01
p<0.01
Keiyu Orthopaedic Hospital, JAPAN
Discussion
Keiyu Orthopaedic Hospital, JAPAN
Return rate by degree of damage in MRI
※
Return
p<0.01, Odds＝9.20
20.9%
n=18
79.1%
n=68
70.9%
n=95
Failure
29.1%
n=39
Mild injury (n=86)
Severe injury (n=134)
 High return rate.
 Poor return rate.
Keiyu Orthopaedic Hospital, JAPAN
Degree of UCL injury among the three groups.
※
Mild
p<0.01
Severe
※
NP
p<0.01
83.1%
n=49
16.9%
n=10
(n=59)
Fragment
51.1%
n=23
48.9%
n=22
53.4%
n=62
46.6%
n=54
(n=45)
(n=116)
Malunion
Normal
 UCL injuries with fragments caused severe damage.
Keiyu Orthopaedic Hospital, JAPAN
Return rate among the three groups
※
Return
p<0.01
Failure
※
NP
p<0.01
71.2%
n=42
28.8%
n=17
(n=59)
Fragment
44.4%
n=20
56.6%
n=25
44%
n=51
55%
n=65
(n=45)
(n=116)
Malunion
Normal
 UCL injuries with fragments had a poor return rate.
Keiyu Orthopaedic Hospital, JAPAN
Consideration of relationship between age
and fragments
Severe injury
Return
≧17 y
＜17 y
13 / 71
26 / 63
Rate
18.3%
41.3%
* Fragment
Severe injury with fragment
Return
4 / 27
≧17 y
3 / 22
＜17 y
Rate
14.8%
13.6%
*
 Avulsion fractures occurring at a young age lead to poorer prognosis
at an early age.
Keiyu Orthopaedic Hospital, JAPAN
Characteristics of cases with severe
UCL injury + fragment.
*
*
*
85.7%
n=42
Severe
14.3%
n=7
*
*
Return
failure
* Fragment
+ Fragment
 The ligament of the distal side of fragment was clearly damaged.
(
)
Keiyu Orthopaedic Hospital, JAPAN
Characteristics of cases with mild UCL
injury + fragment.
*
*
*
100%
(10/10)
*
*
Return
failure
* Fragment
Mild + Fragment
 It was thought that players could return to play with mild damage to the distal
ligament and small fragments
 However, there are not many examples of mild injuries with fragments.
Bad effect of fragments in adolescent elbow
 locus minoris resistentiae of the ligament structure
⇒ a decrease of physiological tension
⇒ attenuation
 higher risk of secondary damage to UCL
⇒ an increasing tendency for severe UCL injuries.
 poorer prognosis at an early age
Keiyu Orthopaedic Hospital, JAPAN
Conclusion
 The presence of fragments in UCL injuries tended to
increase their severity.
 Severe injuries in the fragment group demonstrated
a poor prognosis with conservative treatment.
 The present study showed that prevention and
treatment in low grade-school children are
important against the development of UCL injuries.
Keiyu Orthopaedic Hospital, JAPAN