Chapter 92 - part 3 sesamoid fx and manica flexoria Flashcards
What are the different types of sesamoid bone fracture?
I Apex fractures
II Midbody fractures
III Base fractures
IV Abaxial fractures
V Axial fractures
VI Comminuted fractures
Bones and joints: 1- Third metacarpal bone, 1a- body, 1b- distal metaphysis, 1c- condyle;
2- Fourth metacarpal bone (end); 3- Proximal phalanx, 3a- palmar eminence; 4- Lateral collateral ligament of the metacarpophalangeal joint, 4a- superficial layer, 4b- deep layer; 5- Collateral
sesamoidean ligament of the metacarpophalangeal joint; 6- Palmar (intersesamoidean) ligament,
6a- suprasesamoidean part, 6b- sesamoidean part, 6c - metacarpointersesamoidean ligament;
7- Lateral oblique sesamoidean ligament; 8- Proximopalmar recess of the metacarpophalangeal
joint; Tendons: 9- Dorsal digital extensor tendon; 10- Lateral digital extensor tendon (cut longitudinally),
10a- distal enthesis; 11- Third interosseous muscle (suspensory ligament), 11a- lateral
branch, 11b- lateral extensor branch (cut).
Bones and joints: 1- Third metacarpal condyle (sagittal ridge); 2- Proximal phalanx (medial palmar
eminence); 3-Medial proximal sesamoid bone, 3a- apex, 3b- base; 4- Lateral proximal sesamoid
bone, 4a- interosseous surface, 4b- articular surface; 5- Medial palmar process of the distal
phalanx; 6- Lateral palmar process of the distal phalanx; 7- Metacarposesamoidean joint space;
8- Palmar (intersesamoidean) ligament (suprasesamoidean part); 9- Cruciate sesamoidean ligaments;
10- Straight sesamoidean ligament; 11- Lateral short sesamoidean ligament; 12- Medial
oblique sesamoidean ligament; 13- Lateral oblique sesamoidean ligament; 14- Proximopalmar
recess of the metacarpophalangeal joint; 15- Lateral collateropalmar recess of the MPJ;
Tendons and associated structures: 16- Third interosseous muscle (suspensory ligament),
16a- medial branch, 16b- medial extensor branch, 16c- lateral branch, 16d- lateral extensor
branch; 17- Deep digital flexor tendon, 17a- medial lobe, 17b- lateral lobe; 18- Superficial digital
flexor tendon, 18a- medial branch, 18b- lateral branch; 19- Proximal digital annular ligament,
19a- medial proximal attachment, 19b- lateral proximal attachment; 20- Distal digital annular
ligament; 21- Digital sheath cavity, 21a- transverse synovial plica;
What type of bone is the proximal sesamoid bone (PSB) and how does it affect its function?
Dense cancellous bone; it is prone to fractures due to tension.
What is a significant challenge in the healing of proximal sesamoid bone fractures?
The continual tension and poor blood supply.
How do vascular channels within the PSB relate to fracture risk?
They act as “stress risers,” potentially predisposing the bone to fractures.
What factor contributes to the failure of the PSB under maximal joint extension?
Bending and compressive forces experienced during maximal joint extension.
What are some predisposing factors to PSB fractures mentioned in the text?
Musculotendinous fatigue, poor conformation, shoeing practices, and poor conditioning.
In which breed of horses are apical fractures especially common?
Standardbreds
++ HL
Lateral
in THO is FL
What often dictates the prognosis for horses with apical fractures?
The extent of loss of suspensory ligament insertion and preexisting desmitis
What is the recommended treatment for apical fragments up to one-third of the proximal sesamoid bone?
Removal of apical fragmentsby arthroscopy
describe surgical approach to apical fx of sesamoid
DR or LR with esmarch
In lateral recumbency the arthroscope is inserted through the proximal most aspect of the palmar pouch, whereas the instruments are inserted through a separate incision at the level of the fracture plane. Fracture line easy to see.
Dorsal recumbency allows the insertion of the arthroscope from the contralateral palmar pouch to facilitate better visualization
How does the size of an apical fracture impact the approach to treatment?
Larger apical fractures may require internal fixation in proximal-distal oriented lag screw as mid-body fractures if is one third
What is one advantage of arthroscopic removal of apical fractures?
It results in less-extensive dissection and secondary fibrosis
Recovery the horse with normal bandage in apical fractures?
No, splint bandage in recovery
Apical-abaxial fractures are often..
comminuted
Proximal sesamoid bones in the forelimb are
larger and more elongated than in the hindlimb
The proximal scutum is part of the suspensory apparatus, intercalated between the elastic _____________ ____________ proximally and the inelastic distal _________________ ____________distally
the elastic suspensory ligament
proximally and the inelastic distal sesamoidean ligaments
distally
The distal sesamoidean ligaments are the functional
continuation of the
suspensory ligament to the proximal
and middle phalanges
Name the distal sesamoidean ligaments from dorsal to palmar/plantar (and in corresponding ascending length),
medial and lateral short,
cruciate,
oblique, and the
unpaired straight distal sesamoidean ligaments.
The distal sesamoidean ligaments originate from the base of the proximal sesamoid bones and the ISL.
cancellous bone is weakest in (tension or compression?)
tension
proximal sesamoid bones are not fully mineralized until
3 months of age
Apical fractures are articular?
yes they are almost always articular
Most apical fx can be ID in standard LM, DP, DLMP and DMLP oblique but was is the best view for apical?
20° proximal‐distal obliquity of standard lateromedial
and oblique projections
Dx and tx
Figure 21.5 Acute apical fracture of the medial proximal sesamoid bone, with multiple small proximally displaced comminuted
fragments. (A) Preoperative lateromedial radiograph. (B) Arthroscopic removal of the principal apical fragment of bone
The apical fragment is removed withwhat instrument?
Sharp dissection of the fragment is performed
with straight and curved arthroscopy knives and curved elevator and SL sectioned with arthroscopic scissors or electrocautery probe (to diminish bleeding)
tx
Figure 21.7 Repair of a large apical fracture of a medial proximal sesamoid bone. (A) Lateromedial and (B) dorsomedial‐palmarolateral
oblique (DMPLO) radiographic projections at presentation. (C) Lateromedial projection 10 weeks postsurgery;
note the screw trajectory.
ALL fracture sesamoidean fractures except _______ nonarticular fractures result in MCP/MTP effusion with moderate to severe lameness
abaxial
Prognosis for apical sesamoid fractures
64% surgically tx horses raced afterward
Apical-abaxial are mostly on the FL or HL?
FL
What is the radiograph indicated to see this type of fractures apical abaxial?
**Proximal 60º lateral-distomedial oblique, **proximal 60º medial-distolateral oblique along with standard views
What is the important complementary exam to perform?
US of SL
Acute, comminuted, and displaced apical‐abaxial fracture of a medial sesamoid bone suitable only for fragment removal.(A) Lateromedial, (B) dorsopalmar, (C) dorsolateral‐palmaromedial oblique (DLPMO), and (D) proximolateral‐distomedial obliquepreoperative radiographic projections defining the comminuted nature of the fracture. (E) Longitudinal ultrasound image demonstratingsignificant compromise to all but the most abaxial portion of the suspensory ligament branch and loss of ligament tension followingfracture displacement. (F, G) Contralateral arthroscopic views, at evaluation and following fragment removal and debridement of thesesamoid bone and disrupted suspensory ligament.
Dx and projection
Figure 92-21. Elevated 60-degree lateromedial radiographic projection (L60°Pr-DiMO) of the proximal sesamoid bones to evaluate the intraarticular component of an abaxial sesamoid fracture (arrow). This fragment enters the joint
What surgical technique is required for adequate union of midbody proximal sesamoid fractures?
Internal fixation, screws (single 4.5 or two 3.5mm)
Which screws are used for proximal to distal oriented screw insertion at the apex of the bone in midbody prox sesa fx?
A single 4.5-mm cortex screw or two 3.5-mm screws
From where is screw fixation in lag fashion performed for oblique fractures OF MIBDOY fractures?
From the base or the apex, depending on the fracture plane
Where should the screw head of the cortex screw be positioned when inserting from the base in the case of midbody or basal fractures?
Between the** oblique **and straight distal sesamoidean ligaments in a natural fossa at the base of the sesamoid bone
What is essential for maintaining interfragmentary compression during screw insertion?
Use of large pointed reduction forceps
**What percentage of Thoroughbred horses return to active racing after interfragmentary screw fixation in lag fashion of midbody fx?
Up to 60%
Abaxial fractures have 2 locations name them
Enter the joint (artho tx)
Located palmar/plantarly and is EXTRAARTICULAR (conservative tx)
Figure 21.10 Nonarticular abaxial fracture of a medial sesamoid bone in the forelimb. Surgery is unnecessary. Radiographs including the(A) dorsopalmar, (B) dorsomedial‐palmarolateral oblique (DMPLO), and (C) proximolateral‐distomedial skyline projections define thepalmar abaxial location (arrows), without joint involvement
In which breed of horses are midbody and basal fractures more prevalent?
Thoroughbreds
For which breed of horses has circumferential wiring largely been reserved?
Standardbreds
Figure 21.11 Large articular abaxial fracture of a forelimb medial sesamoid bone, suitable for arthroscopic removal. Radiographs define
the fracture, including (A) dorsopalmar, (B) dorsolateral‐palmaromedial oblique (DLPMO), and (C) proximolateral‐distomedial skyline
projections. Note the dorsal intraarticular position on the skyline. Arthroscopic images obtained from a contralateral palmarolateral portal
show (D) probe evaluation of the fragment displaced from the abaxial margin of the medial sesamoid bone; (E) dissection from the
suspensory ligament insertion with a fixed blade knife; (F) removal of disrupted ligament with a synovial resector; and (G) inspection of
the debrided fracture site.
Abaxial fractures require verification of which structure?
A. SDFT
B. SL
C. DDFT
D. Distal sesamoid ligaments
B. SL
Where is the most common site for abaxial fracture?
FL medial sesamoid bone
What is the prognosis of abaxial fractures?
Depends on teh SLB insertion damag, but article 1998 JAVMA 83% return racing post arthro removal
Are abaxial articular or non-articular fractures?
Both types are possible
How do you treat non-articular abaxial fx?
Conservatively and will heal via fibrous union in 3-6 m rest
Articular abaxial sesamoid are removed by arthroscopy. What is the preferred position?
DR preferrred contralateral scope and ipsilateeral instruments
If a large abaxial fragment is present what should be done?
LAg screw fixation with 3.5/2.7 mm length cortical screws stab incision in SL insertion arthro guided
How do you perform the recovery anesthesia from abaxial fracture?
Cast
Why the poor healing of uniaxial mid-body fractures?
fragment separation distracting forces of suspensory apparatus
Uniaxial mid-body fractures have a:
A. good healing
B. poor healing
B. poor healing
What is the treatment of choice for uniaxial mid-body fractures?
D. lag screw fixation ideally two 4.5 or 3.5mm arthroscopically guided use forceps
What are the ligaments who are in this region?
Short DSL, cruciate DSL, straight DSL, oblique DSL and annular ligament
What other technique could be used beside the placement of screws** uniaxial mid-body fractures**?
Wire technique
Figure 21.15 Acute basilar fracture of a forelimb medial proximal sesamoid bone with sagittal comminution of the distal fragmentstreated with hemicerclage wire. Radiographs useful in identifying the comminuted fragments include (A) dorsopalmar, (B) lateromedial,(C) dorsomedial‐palmarolateral oblique (DMPLO), and (D) dorsoproximomedial‐palmarodistolateral oblique projections. Althoughmeasuring just less than 25% of the proximodistal length of the bone, fractures of this size compromise the suspensory apparatus to thesame degree as mid‐body fractures. (E) Intraoperative dorsopalmar radiograph showing ipsilateral arthroscope position and hemicerclagewire in position; a marker needle has been inserted in the transverse fracture plane. (F) Dorsopalmar radiograph with hemicerclage wire atthe completion of surgery. (G) Dorsopalmar and (H) lateromedial radiographs with the limb immobilized in a cast 10 days post‐surgery.(I) Dorsopalmar and (J) lateromedial radiographs eight weeks post‐surgery; note the periarticular swelling (arrow), which is common withsesamoid wiring. (K, L) Radiographs 12 weeks post‐surgery, showing progressive healing.
Figure 21.13 An acute, transverse, mid‐body fracture of a forelimb medial sesamoid bone repaired with a single 4.5 mm cortical screw.Radiographs show the transverse distracted fracture, including (A) lateromedial, (B) dorsomedial‐palmarolateral oblique (DMPLO), and(C) dorsopalmar projections. Measurements of the proximodistal lengths of the basilar fragment and the contralateral sesamoid bone arecalculated on the dorsopalmar view. (D–G) Determination of drill site and trajectory for distal to proximal repair using needle placementand subsequent lateral and dorsopalmar radiographs.
Figure 21.13 An acute, transverse, mid‐body fracture of a forelimb medial sesamoid bone repaired with a single 4.5 mm cortical screw.Radiographs show the transverse distracted fracture, including (H) “Surgeon’s‐eye” view of drill trajectory and (I) arthroscopically guided reduction.(J, K) Radiographic evaluation of the glide and thread holes, respectively
Interfragmentary screw fixation in lag fashion returns up to % of Thoroughbred horses to active racing for mid body fx
60% whereas circumferential wiring has largely been reserved for Standardbreds
what is the prognosis for horses with basal slab fractures involving the origin of all distal sesamoidean ligaments?
Unfavorable, because it is the orgin of** ALL distal sesamoidean ligaments**
thin fragment is a challenge to insert a screw
What is the preferred method of lag screw fixation for thin basal slab fractures?
Two 3.5-mm cortex screws
What is the return to racing rate for horses with basal osteochondral fragments that do not extend to the palmar/plantar surface?
Approximately 59%
In basal sesamoidean fractures there is an inverse relation between the dorsopalmar/dorsoplantar fragment lenght and
the likehood to return to race
Can you remove the basal sesamoidean fragment by arthroscopy?
yes you can when there is synovial tissue obscuring the fragment
LR or DR and esmarch
Ipsilateral scope and instrument portals vs ipsi/contralateral if dorsal instrument portal just distal to collateral sesamoidean ligament trajectory alongside parallel to base of PSB
How common are sagittal fractures in sesamoid bones?
Rare
With which other injury do sagittal fractures typically occur?
Condylar fractures
Figure 21.18 Axial sagittal fracture of the (A) (B)
lateral proximal sesamoid bone (arrow
heads) associated with a long displaced
fracture of the lateral condyle of a third
metatarsal bone. (A) Dorsoplantar
radiographic projection; (B) arthroscopic
visualization of the fracture (small arrows)
via an ipsilateral arthroscopic portal. Note
the radiologically undetected distal
comminution (large arrow) with minimal
disruption of the articular cartilage
proximally. ISL, intersesamoidean
ligament; LS, lateral sesamoid.
What is a possible repair method for isolated sagittal fractures?
Lag screw fixation, 3.5-mm cortex screws with radiographic monitoring in lateral to medial orientation
ESSENTIAL to have radio control to prevent GLIDE HOLE extending into narrow fracture fragment
Figure 21.19 Fetlock breakdown injurywith comminuted, displaced, biaxialfractures of the forelimb proximal sesamoidbones in a three‐year‐old Thoroughbred.(A) Lateromedial and (B) dorsopalmarprojections show the numerous largefragments of the shattered sesamoids, andsmall comminuted fragments scatteredthroughout the region indicative of thegross soft tissue disruption that isassociated with such injuries. Although theanimal was unwilling to load the leg, notethe hyperextended metacarpophalangealjoint produced by limb weight only.
Fetlock breakdown injury with comminuted, displaced, biaxial fractures of the forelimb proximal sesamoid bones - arthrodesis of the fetlock is required for salvage
Figure 92-22. (A) Lateromedial radiographic projection of the MCP region depicting bilateral transverse midbody fractures of the proximal sesamoid bones resulting in a breakdown of the suspensory apparatus. (B) Repair was achieved through an MCP arthrodesis using a dynamic compression plate (DCP) applied to the dorsal surface of the limb and a tension band wire for palmar support.
Figure 92-23. Axial osteitis of the proximal sesamoid bone. (A) Radiographs show lysis along the axial perimeter of the medial sesamoid bone. (B) T1-weighted MRI better defines the bone lesion and intersesamoidean ligament involvement.
Figure 92-25. (A) Lateromedial radiographic view showing dorsal sagittal ridge OCD (arrow) that involved the adjacent condyle. (B) Arthroscopic examination shows the sagittal ridge (SR) distal to the fragment (arrows), the metacarpal condyle (MC), and villonodular pad (VP).
describe what is the cause of this 8mm mass in the MCP joint
Figure 92-24. Arthroscopic removal of an 8-mm chronic proliferative (villonodular) mass from the MCP joint using a biopsy punch rongeur.
what happened?
Figure 92-28. Luxation of the metacarpophalangeal joint. (A) Standing dorsopalmar radiographic projection shows normal MCP alignment. (B) Bending stress luxates the joint, confirming complete medial collateral ligament rupture.
Figure 92-26. Dorsopalmar radiographic views of the MCP joint. (A) Subchondral cystic lesion with small communication into the joint generally respond well to conservative therapy, such as intraarticular hyaluronan or intralesional corticosteroid injections. (B) SCLs with wide canals (arrows) often need surgical débridement.
dx and tx
Figure 92-27. Subchondral cystic lesion originating from the sagittal groove in the proximal phalanx.
(A) T2-weighted frontal plane MRI and (B) STIR images, show the cyst distal to the sagittal groove and the proximal phalanx. (C) Dorsoplantar radiographic projection 7 days after insertion of a 4.5-mm cortical screw across the sagittal groove cyst, and a 3.5-mm screw inserted further dorsal to treat a second cyst.
FIGURE 8 Tenoscopic visualisation of the digital flexor tendon
sheath of a typical lesion seen at the plantar aspect of the superficial
digital flexor tendon (SDFT) in a case with a concurrent plantar
annular ligament (PAL) constriction; the tenoscope is inserted at the
level of the base of the lateral proximal sesamoid bone and directed
to proximal. The PAL has been transected using a hook knife. Left in
the image the plantar surface of the SDFT can be seen; note the
marked superficial fibrillation and hyperemic surface of the tendon in
the area in contact with the PAL
FIGURE 1 (A) Tenoscopic view of the digital flexor tendon sheath (DFTS); the tenoscope is inserted at the level of the base of the lateral
proximal sesamoid bone and directed to the proximal pouch of the tendon sheath. View of a minor fibrillation seen at the distal margin of the
manica flexoria (MF); this lesion was classified as mild. (B) Tenoscopic view of a case with complete rupture of the MF, categorised as severe.
Note the complete separation of the MF (arrow) from its medial attachment. DDFT, deep digital flexor tendon. (C) Contrast tenogram of the
DFTS corresponding with the case shown above with a rupture of the MF. Note the manica flexoria is not present (only one line, instead of two,
at the level of the MF proximal to the proximal sesamoid bones) (arrow)
FIGURE 4 Contrast radiography of the digital flexor tendon
sheath of a horse with a longitudinal tear at the deep digital flexor
tendon (DDFT). See the linear contrast accumulation within the
outline of the DDFT (arrows)
FIGURE 9 (A) Ultrasonographic image
of a longitudinal lesion at the lateral
border of the deep digital flexor tendon
(DDFT) at the level of the manica flexoria
(MF). Note the irregular appearance of the
lateral DDFT margin with an area of
decreased echogenicity (arrow).
(B) Tenoscopic view of the same DDFT
lesion. The tenoscope is inserted at the
level of the base of the lateral proximal
sesamoid bone and directed to proximal.
Note the significant tendon fibrillation
along the lateral edge of the tendon, the
case was classified as severe
Figure 1. Transverse ultrasound image (lateral is to the left) of the proximal portion of the DFTS distended by anechoic fluid. There is a lesion at the lateral border of the DDFT, evident as a slightly irregular outline of the tendon surface (arrow) with a hypoechoic area within the lateral aspect of the DDFT. Also note the thickening of the subcutaneous tissues (vertical white line) and the wall of the digital flexor tendon sheath. DFTS= digital flexor tendon sheath; DDFT= deep digital flexor tendon; SDFT= superficial flexor tendon.
Figure 2. Transverse ultrasound image, proximal to the fetlock at the level of the MF. Complete rupture of the MF with a complete lateral dislocation (arrow). Note the distention of the DFTS with anechoic fluid. DDFT= deep digital flexor tendon; SDFT= superficial digital flexor tendon; MF= manica flexori
Figure 3. Contrast radiography of the DFTS. A. Normal DFTS with intact MF, visible as two parallel lines (arrow).
The dorsal line is the MF and the palmar/plantar line is the dorsal limitation of the DDFT. B. Rupture of the MF. The
MF is not visible, i.e. there is no double line visible (arrow), only the line at the dorsal aspect DDFT is visible. DFTS =
digital flexor tendon sheath; MF = manica flexoria.
(C) Irregular
soft tissue contour at the plantar aspect
of the limb at the level of the proximal
sesamoid bones (red arrow), unequal
distribution of contrast in the DFTS
proximal and distal to the proximal
sesamoid bones (yellow asterisk) and at
the level of the fetlock canal (red
asterisk) consistent with moderate PAL
constriction. (D) Unequal distribution of
contrast in the DFTS proximal and distal
to the proximal sesamoid bones (yellow
asterisk) and at the level of the fetlock
canal (red asterisk), consistent with
marked PAL constriction.
FIGURE 2 Contrast tenograms of
the digital flexor tendon sheath (DFTS)
depicting various degrees of palmar/
plantar annular ligament (PAL)
constriction. (A) normal contrast
tenogram. (B) Irregular soft tissue
contour at the plantar aspect of the limb
at the level of the proximal sesamoid
bones consistent with mild PAL
constriction (red arrow).
Figure 1 Gross appearance of the manica flexoria with the associated
superficial and deep digital flexor tendons. a) The view from the dorsal
aspect of the manica flexoria showing the portion which apposes the
palmar/plantar wall of the digital flexor tendon sheath. b) Lateral view of the
manica flexoria with the probe inserted between the manica flexoria and the
deep digital flexor tendon, extending beyond the proximal areolar portion.
The opening through the areolar portion of the manica flexoria occurs at the
site of dissection from the dorsal digital flexor tendon sheath wall. c) Palmar
surface of the manica flexoria. The superficial digital flexor tendon has been
split to demonstrate the complete manica flexoria and its attachments.
MF = manica flexoria; SDFT = superficial digital flexor tendon; DDFT = deep
digital flexor tendon.
F I G U R E 1 Transverse ultrasound (US) images of the plantar metatarsal region, obtained proximal to the proximal sesamoid bones in
a non–weight-
bearing
position showing images acquired from patients with a MF tear (medial is to the left of the images). (a) US image
showing the torn edges of the MF floating within the synovial fluid on the side of the MF tear (arrow). (b) US image showing the recoiling of
the MF on the side contralateral to the tear (arrowhead). (c) US image showing the increased distance between medial borders of the SDFT
and DDFT on the side where MF is torn (*). 1 Skin and subcutaneous tissue, 2 SDFT, 3 DDFT, 4 MF. DDFT, Deep digital flexor tendon; MF,
Manica flexoria; SDFT, Superficial digital flexor tendon
FIGURE 2 Transverse ultrasound images of the plantar
metatarsal region obtained proximal to the proximal sesamoid
bones in a non–weight-
bearing
position (medial is to the left of the
images). The image was acquired from a patient with a complete
MF tear. Note the increased distance between medial borders of
the SDFT and DDFT on the side where the MF is torn (*). Also note
the increased gap between MF and DDFT (arrowhead). 1 Skin and
subcutaneous tissue, 2 SDFT, 3 DDFT, 4 MF. DDFT, Deep digital
flexor tendon; MF, Manica flexoria; SDFT, Superficial digital flexor
tendon
FIGURE 3 Transverse ultrasound images of the plantar
metatarsal region, obtained proximal to the proximal sesamoid
bones in a non–weight-bearing position (medial is to the left of the
images). This US image was acquired from a patient that presented
with an acute MF tear. Note the torn edges of the MF floating
within the synovial fluid on the side of the MF tear (arrowhead). 1
subcutaneous tissue, 2 SDFT, 3 DDFT, 4 MF. DDFT, Deep digital
flexor tendon; MF, Manica flexoria; SDFT, Superficial digital flexor
tendon
Figure 92-31. Illustration of tenoscopic annular ligament release, using a slotted cannula inserted from proximal, and an arthroscope inserted from distal to the base of the sesamoid to visualize a 90 degree–angled blade used to sever the fibers of the annular ligament. Inset shows the position of the blade adjacent to the sesamoid abaxial perimeter.
Figure 92-34. Torn manica flexoria of the SDF tendon (SDFT). (A) Ultrasonographic appearance showing the retracted mass (arrow) alongside the DDF tendon (DDFT). (B) Tear along the medial side of the manica (arrows). (C) Free portion of manica (MF) tear.
