ANATOMY-IMAGING SELF- 34
34SCORED SELF- 34
ASSESSMENT EXAMINATIO
34
N
AAOS 2017
34
,Anatomy-Imaging34Self-Scored34Self- Ahmed34Alta
Assessment34Examination342017 ei
Question34134of34100
Figures341a34and341b34are34the34MR34images34of34a3469-year-
old34woman34with34bilateral34leg34pain34that34is34worse34with34ambulation.34She34feels34better34w
hen34she34is34sitting34down34or34leaning34on34a34grocery34cart.34Which34condition34or34structure34
is34indicated34by34the34arrows?
1- Disk34herniation
2- Synovial34cyst
3- Arachnoid34cyst
4- Epidural34lipomatosis
PREFERRED34RESPONSE:342-34Synovial34cyst
DISCUSSION
This34patient34has34neurogenic34claudication34as34demonstrated34by34her34“shopping34cart”34sign.
34Typically,34spinal34stenosis34is34attributable34to34bony34spurs34and/or34a34thick34ligamentum34fl
avum.34However,34for34this34patient,34a34large34synovial34cyst34is34the34main34contributing34facto
r34to34stenosis.34A34cyst34typically34is34filled34with34gelatinous34material.34If34symptomatic,34sur
gical34excision34is34typically34recommended34because34success34with34aspiration34is34unreliable.3
4The34need34for34fusion34is34debatable.
A34disk34herniation34is34not34bright34on34T2.34An34arachnoid34cyst34is34a34sac34filled34with34cere
brospinal34fluid.34Spinal34arachnoid34cysts34are34relatively34uncommon,34and34typically34are34intr
adural,34but34they34also34can34be34extradural.34Epidural34lipomatosis34is34a34condition34caused34by
34excessive34accumulation34of34fat34within34the34epidural34space.34It34is34not34well34circumscribed
34as34seen34with34this34lesion.
RECOMMENDED34READINGS
• Epstein34NE,34Baisden34J.34The34diagnosis34and34management34of34synovial34cysts:34Efficacy34of34s
urgery34versus34cyst34aspiration.34Surg34Neurol34Int.342012;3(Suppl343):S157-
66.34doi:3410.4103/2152-
7806.98576.34Epub34201234Jul3417.34PubMed34PMID:3422905322.34View34Abstract34at34PubMed
1
,Anatomy-Imaging34Self-Scored34Self- Ahmed34Alta
Assessment34Examination342017 ei
• Xu34R,34McGirt34MJ,34Parker34SL,34Bydon34M,34Olivi34A,34Wolinsky34JP,34Witham34TF,34Gokasla
n34ZL,34Bydon34A.34Factors34associated34with34recurrent34back34pain34and34cyst34recurrence34after34
surgical34resection34of34one34hundred34ninety-
five34spinal34synovial34cysts:34analysis34of34one34hundred34sixty-
seven34consecutive34cases.34Spine34(Phila34Pa341976).34201034May341;35(10):1044-
53.34PubMed34PMID:3420173680.34View34Abstract34at34PubMed
2
, Anatomy-Imaging34Self-Scored34Self- Ahmed34Alta
Assessment34Examination342017 ei
Question34234of34100
Figures342a34and342b34are34the34clinical34photographs34taken34at34the34time34of34cubital34tunnel34surgery.3
4The34ulnar34nerve34is34indicated34by34the34red34arrow.34What34is34the34name34of34the34structure34at34t
he34tip34of34the34blue34arrow?
1- Extensor34digitorum34manus
2- Anconeus34epitrochlearis
3- Medial34triceps
4- Flexor34carpi34medialis
PREFERRED34RESPONSE:342-34Anconeus34epitrochlearis
DISCUSSION
The34clinical34photographs34reveal34an34anconeus34epitrochlearis.34This34is34an34atavistic34or34an
omalous34muscle34that34originates34on34the34medial34olecranon34(ulna)34and34inserts34on34the34m
edial34epicondyle.34It34is34widely34present34in34animals34that34move34their34elbows34in34the34corona
l34plane.34The34anconeus34epitrochlearis34muscle34may34be34contributing34a34factor34to34the34develo
pment34of34cubital34tunnel34syndrome.34When34present,34this34muscle34can34compress34the34ulnar3
4nerve34and34should34be34released.
RECOMMENDED34READINGS
• Masear34VR,34Meyer34RD,34Pichora34DR.34Surgical34anatomy34of34the34medial34antebrachial34cutan
eous34nerve.34J34Hand34Surg34Am.34198934Mar;14(234Pt341):267-
71.34PubMed34PMID:342703673.34View34Abstract34at34PubMed
• Masear34VR,34Hill34JJ34Jr,34Cohen34SM.34Ulnar34compression34neuropathy34secondary34to34the34anc
oneus34epitrochlearis34muscle.34J34Hand34Surg34Am.34198834Sep;13(5):720-
4.34PubMed34PMID:343241044.34View34Abstract34at34PubMed
Question34334of34100
Which34nerve34is34at34greatest34risk34in34the34setting34of34an34anterior34shoulder34dislocation?
1- Axillary
2- Musculocutaneous
3- Radial
3
34SCORED SELF- 34
ASSESSMENT EXAMINATIO
34
N
AAOS 2017
34
,Anatomy-Imaging34Self-Scored34Self- Ahmed34Alta
Assessment34Examination342017 ei
Question34134of34100
Figures341a34and341b34are34the34MR34images34of34a3469-year-
old34woman34with34bilateral34leg34pain34that34is34worse34with34ambulation.34She34feels34better34w
hen34she34is34sitting34down34or34leaning34on34a34grocery34cart.34Which34condition34or34structure34
is34indicated34by34the34arrows?
1- Disk34herniation
2- Synovial34cyst
3- Arachnoid34cyst
4- Epidural34lipomatosis
PREFERRED34RESPONSE:342-34Synovial34cyst
DISCUSSION
This34patient34has34neurogenic34claudication34as34demonstrated34by34her34“shopping34cart”34sign.
34Typically,34spinal34stenosis34is34attributable34to34bony34spurs34and/or34a34thick34ligamentum34fl
avum.34However,34for34this34patient,34a34large34synovial34cyst34is34the34main34contributing34facto
r34to34stenosis.34A34cyst34typically34is34filled34with34gelatinous34material.34If34symptomatic,34sur
gical34excision34is34typically34recommended34because34success34with34aspiration34is34unreliable.3
4The34need34for34fusion34is34debatable.
A34disk34herniation34is34not34bright34on34T2.34An34arachnoid34cyst34is34a34sac34filled34with34cere
brospinal34fluid.34Spinal34arachnoid34cysts34are34relatively34uncommon,34and34typically34are34intr
adural,34but34they34also34can34be34extradural.34Epidural34lipomatosis34is34a34condition34caused34by
34excessive34accumulation34of34fat34within34the34epidural34space.34It34is34not34well34circumscribed
34as34seen34with34this34lesion.
RECOMMENDED34READINGS
• Epstein34NE,34Baisden34J.34The34diagnosis34and34management34of34synovial34cysts:34Efficacy34of34s
urgery34versus34cyst34aspiration.34Surg34Neurol34Int.342012;3(Suppl343):S157-
66.34doi:3410.4103/2152-
7806.98576.34Epub34201234Jul3417.34PubMed34PMID:3422905322.34View34Abstract34at34PubMed
1
,Anatomy-Imaging34Self-Scored34Self- Ahmed34Alta
Assessment34Examination342017 ei
• Xu34R,34McGirt34MJ,34Parker34SL,34Bydon34M,34Olivi34A,34Wolinsky34JP,34Witham34TF,34Gokasla
n34ZL,34Bydon34A.34Factors34associated34with34recurrent34back34pain34and34cyst34recurrence34after34
surgical34resection34of34one34hundred34ninety-
five34spinal34synovial34cysts:34analysis34of34one34hundred34sixty-
seven34consecutive34cases.34Spine34(Phila34Pa341976).34201034May341;35(10):1044-
53.34PubMed34PMID:3420173680.34View34Abstract34at34PubMed
2
, Anatomy-Imaging34Self-Scored34Self- Ahmed34Alta
Assessment34Examination342017 ei
Question34234of34100
Figures342a34and342b34are34the34clinical34photographs34taken34at34the34time34of34cubital34tunnel34surgery.3
4The34ulnar34nerve34is34indicated34by34the34red34arrow.34What34is34the34name34of34the34structure34at34t
he34tip34of34the34blue34arrow?
1- Extensor34digitorum34manus
2- Anconeus34epitrochlearis
3- Medial34triceps
4- Flexor34carpi34medialis
PREFERRED34RESPONSE:342-34Anconeus34epitrochlearis
DISCUSSION
The34clinical34photographs34reveal34an34anconeus34epitrochlearis.34This34is34an34atavistic34or34an
omalous34muscle34that34originates34on34the34medial34olecranon34(ulna)34and34inserts34on34the34m
edial34epicondyle.34It34is34widely34present34in34animals34that34move34their34elbows34in34the34corona
l34plane.34The34anconeus34epitrochlearis34muscle34may34be34contributing34a34factor34to34the34develo
pment34of34cubital34tunnel34syndrome.34When34present,34this34muscle34can34compress34the34ulnar3
4nerve34and34should34be34released.
RECOMMENDED34READINGS
• Masear34VR,34Meyer34RD,34Pichora34DR.34Surgical34anatomy34of34the34medial34antebrachial34cutan
eous34nerve.34J34Hand34Surg34Am.34198934Mar;14(234Pt341):267-
71.34PubMed34PMID:342703673.34View34Abstract34at34PubMed
• Masear34VR,34Hill34JJ34Jr,34Cohen34SM.34Ulnar34compression34neuropathy34secondary34to34the34anc
oneus34epitrochlearis34muscle.34J34Hand34Surg34Am.34198834Sep;13(5):720-
4.34PubMed34PMID:343241044.34View34Abstract34at34PubMed
Question34334of34100
Which34nerve34is34at34greatest34risk34in34the34setting34of34an34anterior34shoulder34dislocation?
1- Axillary
2- Musculocutaneous
3- Radial
3
