Shoulder Joint Part 1 Flashcards
1
Q
What cavity covers the humeral head?
A
Glenoid
2
Q
What is the glenoid cavity surrounded by?
A
labrum glenoidale
3
Q
Where does the shoulder joint capsule:
A) Originate?
B) Insert?
A
A) Proximal part of labrum
B) Distal to articular coverage of humeral head
4
Q
The origin of the biceps tendon is surrounded by joint capsule which is in close proximity to what medially?
A
subscapularis muscle
5
Q
The origin of the biceps tendon is surrounded by joint capsule which is in close proximity to what laterally? (2)
A
supraspinatus and infraspinatus muscles
6
Q
Passive stabilisers of the shoulder joint? (4)
A
Mediolateral glenohumeral ligaments
Joint capsule
Labrum glenoidale
Biceps brachii muscle
7
Q
Active stabilisers of the shoulder joint? (4)
A
Supraspinatous muscle
Infraspinatus muscle
Subscapularis muscle
Teres minor muscle
8
Q
What is the normal value for shoulder flexion in a dog?
A
57 degrees
9
Q
What is the normal value for shoulder flexion in cats?
A
32 degrees
10
Q
What is the normal shoulder joint extension in cats and dogs?
A
164 degrees
11
Q
What is the position of a dog for the caudo-lateral approach to the shoulder?
A
Lateral recumbency
12
Q
What anatomical landmarks are identified before proceeding with a caudo-lateral approach to shoulder? (3)
A
Spine f scapula
Shaft of humerus
Great tubercle of humerus
13
Q
Where is the skin incision made for a caudo-lateral shoulder approach?
A
Middle of scapula of spine to shaft of humerus
14
Q
What is exposed on the approach to caudo-lateral shoulder approach after retracted fat.
A
Acromium head and deltoid head of deltoid muscle?
15
Q
Where is the incision made after palpating acromion on the caudo-lateral approach to the shoulder? Extends to?
A
Ventral border of spine of scapula, extend distally to acromial part of deltoid muscle
16
Q
After careful muscle dissection on the caudo-lateral shoulder approach, what is then palpable?
A
Glenoid
17
Q
Where is the teres minor identified on the caudo-lateral approach?
A
Proximally
18
Q
Where is the caudal circumflex artery and vein and muscular branch of axillary nerve identified on the caudo-lateral approach?
A
Distally
19
Q
What can be used on the caudo-lateral approach to protect the axillary nerve?
A
Penrose drain
20
Q
When placing retractors for the caudo-lateral approach, how should the teres minor de displaced?
A
Dorsally
21
Q
which direction is joint capsule incised for a caudo-lateral approach?
A
Longitudingal
22
Q
What retractors for under joint capsule for caudo-lateral approach?
A
Mini gelpi
23
Q
How can we further expose the joint capsule/humeral head in the caudo-lateral approach?
A
Retract joint capsule, internal rotation and flexion
24
Q
Which material is the joint capsule closed in the caudo-lateral approach?
A
Absorbable suture (2-0/3-0)
25
Care must be taken to avoid injury to which nerve when performing the caudolateral approach to the shoulder joint?
The muscular branch of the axillary nerve
26
Is the following step true or false?
External rotation and adduction of the limb allow for maximal exposure of the humeral head.
This sentence is false, the internal rotation and adduction of the limb allow for maximal exposure of the humeral head.
27
How are muscles closed in the caudolateral approach to the shoulder joint?
Reattach the insertions of teres minor muscle +/- infraspinatus muscle.
Suture the intermuscular septum between scapular and acromial part of the deltoid muscle.
Reattach the cranial border of the acromial part of the deltoid muscle to the fascia on the proximal portion of the humeral shaft.
Suture the scapular part of deltoid muscle to the scapular spine.
28
What position is the patient in for Craniomedial region of the shoulder?
Dorsal recumbency
29
For the Craniomedial region of the shoulder how is the skin incision made?
Make a skin incision that starts medial and slightly cranial to the acromion and continues distally ending at the midshaft of the humerus.
30
What is retracted on the first approach to the the Craniomedial region of the shoulder?
Braciocephalicus m
31
What does tenodesis involve of the shoulder joint?
Securing a cut tendon to the proximal humerus
32
Which radiographic view is most useful for identifying irregularities in the intertubercular groove of the proximal humerus?
Flexed craniodistal cranioproximal view
33
For the cranio medial approach, how is the skin incision made?
Make a skin incision that starts medial and slightly cranial to the acromion and continues distally ending at the midshaft of the humerus.
34
What muscle is retracted medially after incising S/C tissue in the cranio medial approach?
Brachiocephalicus m.
35
What needs to be ligated on the cranio medial approach?
omobrachial vein.
36
On the cranio medial approach, order the following steps.
- Retract the pectoral muscles
- Transect the insertion of the deep pectoral muscles
- Transect the insertion of the subscapularis m on the lesser tubercle of the humerus
- Transect the insertion of the superficial pectoral m close to humerus
- Transect the tendon of the coracobrachialis m
- Transect the insertion of the superficial pectoral m close to humerus
- Transect the insertion of the deep pectoral muscles
- Retract the pectoral muscles
- Transect the tendon of the coracobrachialis m
- Transect the insertion of the subscapularis m on the lesser tubercle of the humerus
37
on the cranio medial approach, where is the joint capsule incised?
Parallel to the medial rim of the glenoid cavity.
38
How is the medial joint capsule exposed on the cranio medial approach?
Subscapularis m belly retracted
39
What approach to the shoulder can be used to gain more exposure of the neck and glenoid cavity of the scapula and the humeral head?
The craniomedial approach can be combined with the cranial and craniolateral approach
40
How is the joint capsule closed?
2-0/3-0 interruped absrobable monofilament
41
What order are muscles closed on the cranio medial approach?
Reattach subscapularis muscle.
Attach the pectoral muscles to deltoideus muscle and deep brachial fascia.
Suture of brachiocephalicus muscle to brachial fascia.
Closure of subcutaneous tissue and skin in layers.
42
What is the most common developmental shoulder problem in dogs?
Osteochondrosis dissecans (OCD) of the proximal humerus
43
What age and breed is OCD most commonly seen?
4-8 months
Large/giant breed
44
What breed is over represented for OCD?
Border collie
45
OCD - more common in male or female?
Male
46
What is the incidence range of OCD bilaterally?
27-68%
47
What is Osteochondrosis?
A disturbance of endochondral ossification vulnerable to shear forces
48
What is osteochondritis?
Areas of thickened cartilage may become dislodged from the underlying subchondral bone. The formation of this such flap.
49
What might happen to the OCD flap which results in inflammation/pain?
The OCD flap might reattach to underlying subchondral bone or form a joint mouse which could remain within the joint
50
Where can OCD flaps be resorbed?
Synovial recess at a different location
51
What are the contributary factors for osteochondrosis? (7)
* Genetics;
* Rapid growth;
* Overnutrition;
* Excess dietary calcium;
* Trauma;
* Ischemia;
* Hormonal influences.
52
What is the most common clinical sign of OCD?
Mild-moderate unilateral lameness
53
OCD lameness:
A) Onset time?
B) Changes with rest?
C) Changes with exercise?
A) Gradual
B) Improves
C) Worsens
54
What clinical exam findings may be present with OCD of the shoulder? (5)
- Pain on manipulation
- Pain more prevalent on hyperextension
- Stiff
- Reduced ROM
- Muscle atrophy (chornic)
55
What is seen typically radiographically with OCD? Which view? (4)
Subchondral bone radiolucency or flattening on the caudo-central aspect of the humeral head
Mediolateral radiographs.
Joint effusion
Increased joint space
56
How can OCD lesions be VIEWED on xrays? (2)
Mineralisation of the flap of cartilage is necessary
Joint mice
57
What can be used with xrays to highlight an OCD flap?
+ve contrast arthrogram
58
Where are joint mice seen on xrays with OCD of the shoulder?
In the caudal joint pouch or biceps brachii tendon sheath.
59
What issues do we face with the use of MRI to diagnose OCD?
veterinary machines/software often lacks the resolution needed to fully assess the comparatively thinner canine cartilage.
60
What imaging modality has been shown to identify OCD lesions which xrays may show as unremarkable?
CT
61
What forms of imaging provide more specific information on location and extent of the lesion to aid surgical planning. (3)
CT
CTA (CT arthrography)
MRA (MR arthrography)
62
When may conservative treatment of shoulder OCD be acceptable? (Age and xrays)
dogs less than eight months of age with mild radiographical lesions without the presence of joint mice and no clinical pain
63
What does conservative consist of for shoulder OCD? (6)
- Strict rest for up to 6 weeks
- Restricted diet - calories
- NSAIDS
- OA modifying agents
- Analgesia
- Stop calcium if being supplemented
64
What is happening anatomically for pain and lameness to persist with OCD of the shoulder?
The flap remains attached to the humeral head
65
Does surgery or conservative reduce rate of OA with OCD?
Surgery
66
What are the long term outcomes of arthroscopy vs arthrotomy?
Unequivocal evidence
67
What are 2 benefits of arthroscopy approach to OCD?
- Confirm diagnosis
- Explored some parts of the joint which is less approachable surgically
68
What is the goal of OCD surgery? (4)
- Remove flap
- Remove joint mouse
- Remove cartilage in the periphery of the lesion that is not adhering to the underlying tissue
- Stimulate defect healing
69
Healing of the OCD defect requires bleeding from the A) to bring in B) and B).
A) subchondral bone
B) mesenchymal cells and fibrin clot
70
What fills the OCD defect after surgery?
Fibrocartilage
71
How can bleeding be induced for OCD? (3)
Curettage
Forage
Abrasion arthroplasty
72
What are the alternatives to curettage of the humeral head (2)
Osteochondral allograft transfer (OATS)
Implantation of synthetic plugs (e.g. synacart),
however, clinical data regarding outcome from these procedures are currently lacking.
73
How should a patient be clipped for shoulder arthroscopy?
affected foreleg should be clipped extensively to allow conversion to an open approach if required
74
How is a patient positioned for shoulder arthroscopy?
The patient is positioned in lateral recumbency with the leg to be operated on uppermost.
75
How is the "egress portal" established for artroscopy?
By inserting a 20 gauge, 1.5 inch needle at the craniocaudal midpoint of the superior ridge of the greater tubercle in a caudal and medial direction at a 70º angle from the perpendicular.
76
How is it confirmed intra-articular placement of the needle in arthroscopy?
Attach a syringe to the needle and aspirate synovial fluid to confirm
77
How is the joint distended for arthropscopy?
Distend the joint through egress portal with 10-12 ml of irrigation fluid (e.g. lactated Ringer’s solution). If the needle is in the joint, fluid can be easily instilled.
78
How is an arthroscope portal established?
Establish the arthroscope portal by inserting a needle directly distal or 1-2 mm cranial to the acromial process perpendicular to the skin.
79
How is it confirmed an arthroscope is in position?
Backflow of fluid through the needle placed at the arthroscope portal site confirms its position in the joint
80
How is the arthroscope inserted? How can positioning help?
A small skin incision with a No.11 scalpel blade is made at the needle entry side and the arthroscope cannula with the attached blunt obturator is inserted into the joint. For easier insertion of the arthroscope and to reduce iatrogenic injury the limb should be held in neutral position whilst the assistant applies mild traction on the limb.
81
What shape is the medial collateral ligament of the shoulder?
y
82
The A) of the B) and C) are identified in the D) of the shoulder joint and should be examined for lesions such as tears.
A) Tendon of origin
B) Biceps brachii muscle
C) Supraglenoid tubercle
D) Cranial compartment
83
What are identified when moving the arthroscope in a caudal direction? (2)
- Caudal aspect of glenoid
- Caudal joint pouch
84
Where is the instrument portal established?
2cm caudal and slightly distal to the caudal edge of the acromion. A 20 gauge, 2-3 inch spinal needle is inserted into the joint at a 75-90º angle.
85
Is the following sentence true or false?
The most common reason for unsuccessful triangulation is insertion of the needle at too oblique an angle.
True
86
For a flap removal and abrasion arthroplasty of an OCD lesion of the caudal humeral head via open arthrotomy we will approach to the A) region of the shoulder joint?
Caudal
87
How can the limb be manipulated to aid the exposure of OCD lesions for a caudo lateral approach to the shoulder?
Internal rotation of the limb
88
Caudolateral approach:
How is the OCD flap removed? (2)
Forceps
Graspers
89
Where should be inspected for OCD joint mice in caudo-lateral surgery?
- Caudal joint pouch
- Bicipital bursa
90
Following flap and mice removal, what should happen with the remaining subchondral defect?
Debride (sharp spoon, hand burr, power shaver) until bone bleeding present
91
What layers are closed following caudo medial approach?
(monofilament absorbable suture material, 2-0 / 3-0, simple interrupted suture pattern), intermuscular septum, deep fascia, subcutaneous tissue and skin.
92
The modified Cheili approach to the shoulder is indicated for which of the following procedures?
Removal of an OCD flap
93
What needs to identified on the Modified Cheili approach to the shoulder? (4)
- Acromion process
- Greater tubercle
- Acromial head of deltoid
- Supraspinatus
94
How is an incision made on the Modified Cheili approach to the shoulder?
From the acromion to the greater tubercle of the humerus.
95
Modified Cheili approach:
Continued dissection between the acromial head of the deltoid muscle and the supraspinatus. what is now visible?
The acromial head of the deltoid and the underlying infraspinatus and the supraspinatus cranially are now visible.
96
What is the entry point with the Modified Cheili approach?
The entry point to the joint is between the supraspinatus and the infraspinatus.
97
Modified Cheili:
Make a longitudinal incision into the joint capsule exposing the humeral head and the glenoid of the scapula.
Which ligament do you need to be careful when performing the previous incision?
Lateral collateral ligament.
98
Closure of the Modified Cheili: Suture the fascia of the A) and B).
A) supraspinatus
B) acromial head of the deltoid
99
Long term prognosis of OCD after surgery?
Excellent
100
How long does it take for a dog to become sound following OCD surgery?
7-60 days
