Shoulder Flashcards
1
Q
What are the intrinsic causes of shoulder pain?
[JAAOS 2015;23:492-500]
A
2
Q
What are the extrinsic causes of shoulder pain?
[JAAOS 2015;23:492-500]
A
3
Q
What are the advantages and disadvantages of lateral decubitus and beach chair positions for arthroscopic or open shoulder surgery?
[JAAOS 2015;23:18-28]
A
- Lateral Decubitus
- Advantages
- Traction increases space in the glenohumeral joint and subacromial space
- Traction accentuates labral tears
- Operating room table and/or patient’s head not in the way of posterior and superior shoulder
- Cautery bubbles move laterally out of view
- No increased risk of hypotension/bradycardia
- Better cerebral perfusion
- Disadvantages
- Nonanatomic orientation (ie, glenoid is parallel to the floor)
- Must reach around arm for anterior portal
- May need to reposition and redrape to convert to open procedure
- Not ideal for patients who cannot tolerate regional anesthesia
- Traction can cause neurovascular and soft-tissue injury
- Increased risk of injury to axillary and musculocutaneous nerves when placing anteroinferior portal
- Beach Chair
- Advantages
- Upright, anatomic position
- Ease of examination under anesthesia and ability to stabilize the scapula
- Arm not in the way of anterior portal
- No need to reposition or redrape to convert to open procedure
- Can use regional anesthesia with sedation
- Mobility of surgical arm and ability to set up arm holder to the operating room table
- Disadvantages
- Potential mechanical blocks (eg, the head) to the use of arthroscope in posterior or superior portals
- Increased risk of hypotension/bradycardia causing cardiovascular complications (ie, cerebral ischemia)
- Cautery bubbles obscure view in the subacromial space
- Fluid can fog camera if there is a leak in the attachment or in certain cameras
- Theoretically increased risk of air embolus
- Expensive equipment if using beach-chair attachment with or without mechanical arm holder
4
Q
What is the normal glenoid inclination (tilt)?
[J Am Acad Orthop Surg 2015;23:317-326]
A
Glenoid inclination/tilt = the slope of the glenoid face in the superior-inferior direction relative to a line drawn perpendicular to the tangent of the medial scapular border
- Average of 2.2° of inferior tilt to 4.2° of superior tilt (range of -12-15.8°)
?B-angle
- Angle between glenoid face line along scapular spine
- Inclination angle is 90 - Bangle
5
Q
What is the normal glenoid version?
[J Am Acad Orthop Surg 2015;23:317-326]
A
Glenoid version = the angle between the glenoid surface and a line drawn perpendicular to the axis of the scapular spine
- Average of 2° of retroversion (range of 12° anteversion to 14° retroversion)
6
Q
What is the glenoid vault?
[J Am Acad Orthop Surg 2015;23:317-326]
A
It is the triangular bone extending from the glenoid articular surface to the body of the scapula (serves as the bony support for the glenoid component in shoulder arthroplasty)
7
Q
How is glenoid version measured?
[The Open Orthopaedics Journal, 2017, 11, (Suppl-6, M4) 1115-1125]
A
Friedman method
- Friedman line drawn from the medial scapular border to the center of the glenoid on CT
- A line perpendicular to the Friedman line is drawn from the anterior edge of the glenoid
- A line drawn from the anterior to posterior edge of the glenoid
- If the posterior edge of the glenoid is anterior = anteverted
- If the posterior edge of the glenoid is posterior = retroverted
8
Q
Walch classification of glenoid morphology associated with primary glenohumeral OA
[JAAOS 2012;20:604-613]
A
- Type A – concentric wear with no subluxation (59%)
- Subtype A1 – minor
- Subtype A2 – major
- Line connects anterior/posterior glenoid rims and transects humeral head (HH)
- Type B – posterior humeral subluxation with asymmetric wear of the posterior glenoid rim (32%)
- Subtype B1 – posterior joint space narrowing but no posterior erosion
- Subtype B2 – posterior erosion and biconcave appearance
- Subtype B3 - monoconcave, posterior wear, at least HH subluxation >70% OR retroversion >15%
- Type C – dysplastic glenoid with glenoid retroversion >25°and posterior humeral head subluxation (9%)
- Type D - Glenoid anteversion or anterior HH subluxation
9
Q
What imaging modality is needed to evaluate glenoid morphology?
[JAAOS 2012;20:604-613]
A
CT with 3D recon – assess version, bone stock, vault anatomy
10
Q
In a B2 glenoid what does each concavity represent?
[Curr Rev Musculoskelet Med. 2016 Mar; 9(1): 30–39.]
A
- Anterior concavity = paleo glenoid (native glenoid)
- Posterior concavity = neoglenoid
11
Q
What are the complications associated with TSA from most to least frequent?
[JBJS 2017;99:256-69]
A
- Component loosening (glenoid > humeral)
- Glenoid wear
- Instability
- Rotator cuff tear
- Periprosthetic fracture
- Neural injury
- Infection
- Hematoma
- Deltoid injury
- VTE
12
Q
What is the most common long-term complication of TSA?
[JAAOS 2015;23:317-326]
A
Glenoid loosening (24% of all TSA complications)
13
Q
What factors contribute to glenoid loosening?
[JAAOS 2012;20:604-613]
A
- Altered joint reaction forces
- Component malposition
- Insufficient bony support (native glenoid)
14
Q
What are the indications, absolute and relative contraindications for glenoid resurfacing in TSA?
[JAAOS 2015;23:317-326]
A
Indications
- Painful glenoid degeneration
- Adequate glenoid bone stock
- Intact rotator cuff
Absolute contraindications
- Active shoulder infection
- Neuroarthropathy
- Paralysis of shoulder muscles
Relative contraindications
- Age <50
- High functional demand
- Significant bone loss
- Rotator cuff dysfunction
15
Q
What is the rocking horse phenomenon?
[JAAOS 2015;23:317-326]
A
The mechanism by which the glenoid component loosens overtime
- Occurs when the component is edge loaded causing compression on one side and distraction on the other resulting in the breakdown at the bone implant interface
16
Q
What factors lead to or worsen the rocking horse phenomenon?
[JAAOS 2015;23:317-326]
A
- Glenohumeral instability
- Rotator cuff dysfunction
- Glenoid malposition in retroversion or superior inclination
17
Q
What are revision options for glenoid component failure?
[JAAOS 2015;23:317-326]
A
- Component reimplantation in one or two stages
- Glenoid removal without reimplantation
- Isolated glenoid bone grafting
- Reverse TSA
18
Q
New What are causes of anterior instability in TSA?
A
- component malposition (anteversion)
- anterior glenoid deficiency
- surgical deltoid takedown
- axillary nerve injury
- failure of subscapularis repair
19
Q
new - What are causes of superior instability in TSA?
A
rotator cuff deficiency
20
Q
New - what are causes of posterior instability in TSA?
A
- posterior glenoid deficiency
- component malposition (retroversion)
- posterior capsular redundancy
21
Q
What are surgical options for advanced glenoid deformity in TSA?
[JAAOS 2015;23:317-326]
A
- Downsizing glenoid component
- Slight undercorrection and implantation in retroversion
- Bone grafting (native osteotomized humeral head)
- Nonprosthetic resurfacing
- “ream-and-run” (ream glenoid without implanting glenoid component)
- Soft tissue interposition
- Augmented implants
- Reverse TSA
22
Q
What are the principles for glenoid component implantation?
[JAAOS 2015;23:317-326]
A
- Adequate glenoid exposure and visualization (through soft tissue releases and optimal retractor placement)
- Recognition and correction of deformity
- Preserve bone stock and subchondral bone avoiding perforation of the glenoid vault
- Proper implant sizing
- Proper implantation of prosthesis with cement pressurization and full seating of the component in appropriate position
23
Q
What are treatment options for management of glenoid retroversion and posterior glenoid bone loss in TSA?
[JBJS 2015;97:251-9][JSES (2013) 22, 1298-1308]
A
- <15° = Eccentric reaming
- 15-25° = augmented glenoid components
- >25° = glenoid bone grafts
- Elderly, sedentary patients = reverse TSA
24
Q
What are the advantages and disadvantages of eccentric reaming for management of posterior glenoid bone loss?
[JBJS 2015;97:251-9]
A
Advantages
- Technically simple
- Quick
Disadvantages
- Reduction of subchondral bone
- Medialization of joint line
- Risk of poly peg cortical perforation
25
What are the advantages and disadvantages of glenoid bone grafts for management of posterior glenoid bone loss?
[JBJS 2015;97:251-9]
Advantages
* Improves version
* Reestablishes joint line
* Restores bone stock
Disadvantages
* Technically demanding
* Risk of nonunion
* Resorption
* Subsidence
26
What are the advantages and disadvantages of augmented glenoid components for posterior glenoid bone loss?
[JBJS 2015;97:251-9]
Advantages
* Improves glenoid version
* Prevents implant perforation, joint line medialization and subchondral bone loss
Disadvantages
* Technically demanding
27
What are the advantages and disadvantages of reverse TSA for posterior glenoid bone loss?
[JBJS 2015;97:251-9]
Advantages
* Improved constraint
* Improved fixation
28
What is the classification of periprosthetic humerus fractures?
[JAAOS 2008;16:199-207]
Wright and Cofield
* Type A - near the tip and extend proximally
* Type B - near the tip and extend distally
* Type C - distal to the tip
29
What is the management of periprosthetic humerus fractures?
[JAAOS 2008;16:199-207]
Nonoperative
* Indications
* Minimally or nondisplaced
* Stable humeral component
* Alignment maintained in fracture brace/orthosis
* Type C fractures
Operative
* Indications
* Unacceptable alignment
* Unstable humeral component
* Delayed or nonunion (consider after 3 months of nonop)
30
What is the management of intraoperative humerus fracture while doing shoulder arthroplaty?
[JAAOS 2008;16:199-207]
Type A and B
* Long stem prosthesis, bypass by 2-3 cortical diameters
* If cemented component already inserted perform ORIF with plate and screw/cerclage
Type C
* Long stem prosthesis if proximal enough
* ORIF with plate and screw/cerclage if too distal
31
What is the management of postoperative fractures?
[JAAOS 2008;16:199-207]
Type A
* Treat as loose component if length of fracture is similar to length of stem, \>2mm displacement, \>20° angulation
* Long stem prosthesis, bypass by 2-3 cortical diameters
* Augment with strut graft or plate
Type B
* Loose component
* Long stem prosthesis, bypass by 2-3 cortical diameters
* +/- Augment with cement in distal canal
* +/- Augment with strut graft or plate
* Stable component
* ORIF with plate and screws/cerclage
Type C
* Trial of nonoperative
* Failed nonoperative
* ORIF with plate and screws/cerclage
32
what is the etiology of GH arthritis in the young patient
1. primary OA
* results in posterior glenoid wear and internal rotation contractures
2. secondary OA
* infection
* post-traumatic
a. GH dislocatoin or subluxation
b. fracture malunion
* ostenecrosis
* iatrogenic
a. intra-articular screw penetration following ORIF
b. direct mechanical injury (e.g. scope cameral or instruments)
c. thermal injury (Radiofrequency devices)
d. "capsulorrhaphy arthropathy" = rapid posterior chondral wear due to over tightening of the anterior capsule
* glenoid dysplasia
33
What are the treatment options for GH arthritis in the young patient?
1. Nonoperative
* Activity modification
* Pharmacological
* Physical therapy
* Intra-articular injections
2. Operative
* Arthroscopic debridement and capsular release
* CAM – comprehensive arthroscopic management
* Biological replacement
* Microfracture
* Osteochondral autograft/allograft
* ACI
* Humeral arthroplasty without glenoid treatment
* Full replacement
* Partial replacement
* Stemmed
* Stemless
* Humeral arthroplasty with glenoid treatment
* Biologic interpositional resurfacing
* Achilles allograft
* Meniscus allograft
* Fascia lata
* Acellular dermal scaffold graft
* “Ream and run”
* Anatomic TSA
* Corrective osteotomy of glenoid
* Arthrodesis
* rTSA
34
what are the indications for different treatment options for young patients with GH arthritis
1. arthroscopic debridement and capsular release
- mild OA
- joint space visible on radiograph
- minimal osteophyte formation and subchondral sclerosis/cysts, osteochondral lesion <2cm^2
- concentric joint space
2. biological replacement
1. focal contained chondral leson in whom the subchondral plate is maintained and the lesion is <2cm^2 in size
3. humeral arthroplasty without glenoid treatment
1. young patient with unipolar disease (glenoid preserved)
4. humeral arthroplasty with glenoid treatment
1. young patient with bipolar disease
2. ream and run can be used in eccentric glenoids as reaming can create a concentric joint
5. anatomic TSA
1. severe bipolar disease withi ntact cuff
2. low demand patient with eccentric glenoids as reaming can create a concentric joint
6. corrective osteotomy of glenoid
1. symptomatic, fixed posterior subluxation and posterior glenoid wear
7. arthrodesis
1. end-stage OA in patients with strenuous physical demands (heavy manual labor)
2. multiple failed surgeries
3. voluntary dislocators
4. failed arthroplasty
5. massive cuff tear with deltoid deficiency
6. severe neurological injury
7. chronic infection
8. rTSA
1. low demand
2. limited preop function
3. failed rotator cuff repair or other arthroplasty means
4. rotator cuff arthropathy
35
what are indications and contraindications for comprehensive arthroscopic management
- indications
- advanced symptomatic GH arthritis
- young (<50yo)
- active patient
- desire for joint preservation
- failed nonsurgical management
- absolute contraindications
- mild GH arthritis
- nonsurgical treatment not yet attempted
- incongruous joint space and severe deformity
- inflammatory GH arthritis
- relative contraindications
- <2mm GH joint space
- severely limited GH PROM (esp IR)
- large osteophytes
- bipolar chondral leions
- low critical shoulder angle
- kellgren-lawrence grade III or IV arthritis
- walch B2 or C glenoid changes
36
what are advantages and disadvantages of CAM?
- advantages
- joint preserving
- retaining native anatomy does not preclude future treatment options
- delays or avoids arthroplasty
- disadvantages
- technically demanding procedure
- additional surgery as patient may require future arthroplasty
- novel procedure with unknown longterm outcomes
37
what pathologies can be addressed with CAM
1. synovitis - synovectomy
2. adhesion - debridement
3. cartilage fraying - chondroplasty
4. loose bodies - loose body removal
5. goat’s bear deformity - inferior humeral osteoplasty
6. axillary nerve impingement and adhesions - axillary nerve neurolysis
7. capsular tightness/decrease ROM - capsular release
8. subacromial impingement - subacromial decompression
9. subacromial impingement - subcoracoid decompression
10. focal chondral defects - microfracture
38
What are the causes of anterior instability in TSA?
[JBJS 2017;99:256-69]
1. Component malposition (anteversion)
2. Anterior glenoid deficiency
3. Surgical deltoid takedown
4. Axillary nerve injury
5. Failure of subscapularis repair
39
What are the causes of superior instability in TSA?
[JBJS 2017;99:256-69]
Rotator cuff deficiency
40
What are the causes of posterior instability in TSA?
[JBJS 2017;99:256-69]
1. Posterior glenoid deficiency
2. Component malposition (retroversion)
3. Posterior capsular redundancy
41
What are the 4 key principles of the Grammont style rTSA?
[JSES (2015) 24, 150-160]
1. The center of rotation must be fixed, distalized and medialized to the level of the glenoid surface
2. The prosthesis must be inherently stable
3. The lever arm of the deltoid must be effective from the start of movement
4. The glenosphere must be large and the humeral cup small to create a semiconstrained articulation
42
Where is the center of rotation in a rTSA?
[JSES (2015) 24, 150-160]
Bone-implant interface of the glenosphere
* Maximizes compressive forces and minimizes shear forces
43
What are the disadvantages of medialization of the center of rotation in a rTSA?
[JSES (2015) 24, 150-160]
1. Scapular notching
2. Reduced ROM
3. Loss of shoulder contour
44
What is the cause of scapular notching?
[JSES (2015) 24, 150-160]
Mechanical impingement of the superomedial humeral prosthesis against the inferior scapular neck during adduction
45
what is the classification system for scapilar notching
1. sirveaux classification
1. grade 1 - defect confined to the pillar
2. grade 2 - defect extends to the lower screw
3. grade 3 - defect encompasses lower screw
4. grade 4 - defect extends under the baseplate (indicates loosening)
46
What strategies have been proposed to avoid scapular notching?
[JSES (2015) 24, 150-160]
1. Eccentric inferior glenosphere position
2. Inferior inclination of the glenoid component
3. Increased lateral offset
4. Decreased inclination (neck-shaft angle) of the humeral component
47
What are the benefits of eccentric (inferior) glenosphere placement in rTSA?
[JSES (2015) 24, 150-160]
1. Decreased notching
* Inferior overhang of the glenosphere provides space between the glenosphere and scapular neck
2. Increased impingement-free ROM
* Creates additional clearance between the GT and coracoacromial arch
48
What are the advantages and disadvantages of lateral offset in rTSA?
[JSES (2015) 24, 150-160]
Advantages
* Increased ROM
* Prevents impingement between the tuberosities and the coracoid process during IR and scapular spine during ER
* Restores length-tension relationship and moment arm of subscapularis and teres minor
Disadvantages
* More stress at bone-implant interface
* Glenosphere unscrewing, baseplate loosening, migration of the glenosphere
49
What is the effect of increasing the humeral neck-shaft angle in rTSA?
[JSES (2015) 24, 150-160]
1. Normal Grammont inclination = 155
2. With increasing neck-shaft angles there is impingement between the polyethylene cup and inferior scapular neck
50
What is the effect of increasing the humeral retroversion in rTSA?
[JSES (2015) 24, 150-160]
1. Normal Grammont retroversion = 20-40
2. With increasing retroversion there is increased ER and decreased IR before impingement
51
The rTSA is inherently stable; however relative instability is found in what shoulder position?
[JSES (2015) 24, 150-160]
Full adduction
* Likely due to inferior impingement which results in levering effect and distractive forces
52
What is the effect of the rTSA on the deltoid?
[JSES (2015) 24, 150-160]
1. Re-tensions the deltoid
* Effective in early abduction but loses tension and subsequent strength after 90°
2. Increases the moment arm (by 20-42%)
* Increases torque capacity, particularly in early abduction
* Less muscle force required to generate force
3. Recruits additional fibers of the anterior and posterior deltoid
* All 3 heads demonstrate primarily abductor function (nearly all fibres are lateral to center of rotation)
* Native shoulder anterior fibres primarily flexors, middle fibres abductors and posterior fibres extensors
* Relies on rotator cuff for rotation (may be limited if torn)
53
What is the effect of the rTSA on the rotator cuff?
[JSES (2015) 24, 150-160]
1. Decreases rotational moment arm of the subscapularis and teres minor
2. Decreases length-tension relationship of subscapularis and teres minor
3. May reduce active IR and ER affecting ADLs
54
new - how do you assess soft tissue tension in rTSA?
- axial shuck test -axial traction on adducted humerus (optimal is 1-2mm of gapping)
- lateral instability - lateral dislocation force applied with one finger on calcar (assess ease of dislocation/subluxation)
- adduction deficit - gravity adduction (due to overlengthened humerus or glenoid baseplate too superior
- strap muscle tightness - in neutral extension should contribute to joint compression
55
new - how can you adjust the soft tissue tension in rTSA
- increase poly size,
- implant humeral stem proud or deep,
- change glenosphere diameter,
- lateralize the glenosphere
56
new- what is the importance of tuberosity union in rTSA?
- improved ER
- note
- in both hemiarthroplasty and rTSA, healing of the GT leads to superior clinical outcomes
- however, in rTSA healing of the GT is not a prerequisite for a good outcome
57
The outcomes of rTSA are inferior in the presence of a nonfunctioning teres minor (pseudoparalysis of ER), what intervention can be employed in this scenario?
[JAAOS 2009;17:284-295]
Latissimus dorsi transfer
58
What are the 3 columns of bone available in the scapula for locking screw fixation of the baseplate?
[JSES (2015) 24, 150-160]
1. Base of the coracoid
2. Scapular spine
3. Scapular pillar
59
60
new- what are the radiographic features of cuff tear arthropathy
1. superior humeral head migration (decreased acromiohumeral space)
2. acetabulization of the acromion
3. femoralization of the humeral head (rounding of the GT)
4. eccentric superior glenoid wear
5. osteopenia
6. snowcap sign
7. (subarticular sclerosis)
8. absence of the typical peripheral osteophytes (lack inferior and medial humeral head osteophytes)
61
new - what is the radiographic classification of massive rotator cuff tears with progression to cuff tear arthropathy
hamada classification - grades reflect the temporal evolution of RC tears
**| * Grade 1 | **
Acromiohumeral interval ≥ 6mm
**| * Grade 2 | **
Acromiohumeral interval≤ 5mm
**| * Grade 3 | **
Acromiohumeral interval ≤ 5mm, with acetabularization of acromion |
**| * Grade 4 | **
4A: Glenohumeral arthritis without acetabularization, AHI < 7mm
4B: Glenohumeral arthritis with acetabularization, AHI ≤ 5mm
**| * Grade 5 | **
humeral head collapse
| * Grade 1 |
62
new - what is pseudoparalysis of the shoulder
- defined as **inability to actively elevate the arm in the presence of free PROM** and in the absence of neurologic lesions
- occurs as a result of superior migration of the humeral head due to unopposed deltoid contraction in the prsence of a RC tear (loos of the inferior directed force
63
new - what is the management of rotator cuff arthropathy?
1. first line - nonop
1. PT, injections, activity modifications
2. operative
1. shoulder arthrodesis
1. indication - significant anterior deltoid deficiency, multiple previous surgeries
2. arthrscopic, debridement
1. indication - multiple medical co-morbidities, high risk patient
3. hemiarthroplasty (typically, cuff tear arthropathy (CTA) prosthesis)
1. indication - intact deltoid, intact CA ligament, FF>90, ER>30
4. rTSA
1. indication - intact deltoid, incompetent CA ligament, elderly, low demand
64
What is the main indication for a rTSA?
[JAAOS 2009;17:284-295]
1. Symptomatic, irreparable rotator cuff tear with irrecoverable pseudoparalysis of anterior elevation and/or abduction
2. Preserved deltoid function and structure
3. Adequate glenoid bone stock and quality
65
What are other indications for rTSA?
[CORR (2010) 468:1526–1533]
1. Cuff tear arthropathy
2. Chronic pseudoparalysis with massive cuff tear without arthritis
3. Inflammatory arthritis with massive cuff tear
4. Proximal humerus fractures
5. Proximal humeral nonunion/malunion
6. Revision arthroplasty
7. Tumor
66
What are contraindications for rTSA?
[JAAOS 2009;17:284-295] [CORR (2010) 468:1526–1533]
1. Deltoid dysfunction
2. Infection
3. Neuroarthropathy
4. Glenoid bone erosions or defects
5. Severe osteopenia (relative)
67
What are the advantages of a superolateral vs. deltopectoral approach in rTSA?
[JAAOS 2009;17:284-295]
Superolateral
* Advantages
* Less instability
* Less scapular spine and acromion fractures
Deltopectoral
* Advantages
* Better active ER
* Better glenoid component orientation
* Less glenoid loosening
* Less scapular notching
* Easier for revision surgery
68
What are the complications associated with rTSA from most frequent to least?
[JBJS 2017;99:256-69]
1. Instability
2. Periprosthetic fracture
3. Infection
4. Component loosening
5. Neural injury
6. Acromial and/or scapular fracture
7. Hematoma
8. Deltoid injury
9. Rotator cuff tear
10. VTE
69
What is the classification system for scapular notching in rTSA?
[JAAOS 2011;19:439-449]
1. Sirveaux classification
* Grade 1 - defect confined to the pillar
* Grade 2 - defect extends to the lower screw
* Grade 3 - defect encompasses lower screw
* Grade 4 - defect extends under the baseplate (indicates loosening)
70
What factors predispose to acromial fracture in rTSA?
[JAAOS 2011;19:439-449]
1. Superior screw that exits at the junction of the acromion and scapular spine
2. Excessive deltoid tension
3. Osteopenia
71
What is the most common complication following rTSA?
[JAAOS 2018;26:587-596]
Instability
72
what is scapular notching and what are the predictors of notching
- radiographic findings likely due to contact between the scapular neck and poly during adduction
- associated with loss of baseplate fixation, poor patient outcomes and is an independent risk factor for failure
- predictors of notching include
- superior position of glenosphere
- medialization of the center of rotation
- high BMI
73
What are risk factors for instability following rTSA?
[JAAOS 2018;26:587-596]
1. BMI >30
2. Subscapularis deficiency
3. Previous surgery
4. Surgical approach
* Deltopectoral higher dislocation vs. superolateral
5. Bone deficiency
6. Previous trauma
74
What is the most common direction and timing of instability following rTSA?
[JAAOS 2018;26:587-596]
1. Anterior (and superior)
2. Early (first 3 months)
75
What is the position at risk for anterior dislocation in rTSA?
[JBJS 2017;99:256-69]
Adduction, extension, internal rotation
76
What technical/implant factors affect rTSA stability?
[JAAOS 2018;26:587-596]
1. Socket constraint
* Depth of the humeral socket
* Increasing the ratio of the humeral implant socket to the radius of the glenosphere head increases stability
* That is, increasing the depth of the humeral socket increases stability if the glenosphere remains the same size
* Also increases impingement and ROM loss
2. Eccentric (inferior) glenosphere positioning
* Glenosphere should be placed as inferior as possible while ensuring good fixation
3. Glenosphere tilt
* Inferior tilt 10-15° can increase stability and impingement
4. Glenosphere lateralization
* Lateralization improves stability but puts more stress at the bone-implant interface
* Avoid over aggressive reaming as it will medialize the glenosphere
* Limit reaming to correct version and inclination
5. Humeral lengthening
* Humeral lengthening improves stability
* Also decreases deltoid efficiency and increases joint reaction forces
* Up to 2cm of lengthening is recommended
6. Humeral lateralization
* Humeral lateralization improves stability and decreases deltoid forces (reduces deltoid fatigue and acromial fractures)
Note:
* Glenosphere size does not affect stability
* Neck shaft angle does not affect stability
* Humeral and glenosphere version should be based on ROM rather than effect on stability
* Recommend humeral version 0-30°
* Subscapularis repair does not affect stability
* Surgeon experience does not affect stability
77
What is the management of a dislocated rTSA?
[JAAOS 2018;26:587-596]
1. Technique for closed reduction
* Clinic or monitored setting if sedation needed
* Shoulder is abducted to 45° in neutral rotation; apply longitudinal traction and posterior and inferior force to proximal humerus
* Note – humerus lies anterior and superior to glenosphere
2. Three basic methods for increasing stability and deltoid tension:
* Lateralizing and/or upsizing the glenosphere
* Use of a retentive or more constrained polyethylene insert
* Distalizing the humerus by increasing the polyethylene thickness
3. In general, the algorithm would follow:
* Perform closed reduction of dislocated rTSA
* Unsuccessful = open reduction
* Successful = immobilize in abduction for 4-6 weeks
* 1. Stable = manage nonoperative
* 2. Recurrent instability = closed reduction followed by workup for etiology
* Workup includes scaled full length humerus radiograph, AP and axillary radiograph, CT scan, WBC/ESR/CRP
* Possible etiologies:
* Infection (elevated ESR/CRP and positive aspiration)
* \<3 months = I&D and liner exchange
* \>3 months = one or two-stage revision
* .Humeral shortening
* Humeral length – measured distance between the acromion and the epicondyle compared to the contralateral side (radiographically)
* \<15mm = thicker poly ± metal spacer ± retentive liner ± glenosphere change
* \>15mm = humeral component revision ± proximal humeral allograft
* Humeral medialization
* Measured as the distance between the humeral axis and the lateral acromion
* \<15mm = larger glenosphere ± increased lateral offset
* \>15mm = glenoid baseplate revision with augment or lateralizing structural bone graft
78
most common causative bacteria in PJI infections of the shoulder
- cutibacterium acnes (38.9%)
- staph aureus 14.8%
- staph epidermidis (14.5%)
- coagulase-negative staph (14%)
79
RF of PJI of shoulder
- male
- higher BMI
- younger age
- immunosuppressed conditions and meds
- post-truma
- rTSA
- previous surgery
80
what can be included in preop workup for shoulder PJI
1. Bloodword
1. ESR, CRP, WBC
1. high specificity and PPV but poor sensitivity and NPV due to low-virulence infection
2. joint aspiration
1. can be performed to assess cell count and cultures
2. cutoff values have not been established in the shoulder and aspiration often does not yield enough fluid for the analysis and culture
3. tissue culture
1. arthroscopic tissue biopsy may be most beneficial in the clinical scenario of a painful arthroplasty without overt signs of infection or in the arthroplasty with presumed aseptic loosening
81
what is the management of a prosthetic joint infection of the shoulder
1. acute infection (timing not well defined)
1. I&D with exchange of modular components and retention of implants
2. chronic infection
1. single-stage aor two-stage revision - equivocal results in terms of infection eradication
1. 2 stage involves
1. implant removal
2. I&D, removal of cement and periarticular tissue
3. tissue culture
4. antibiotic cement spacer
5. IV antibiotics for minimum 6 wks
6. second stage reimplantation of prosthesis
2. single stage involves
1. implant removal
2. I&D, removal of cement and periarticular tissue
3. tissue culture
4. reimplantation of new prosthesis
5. IV antibiotics for 6 weeks followed by oral antibiotics
82
what are considered appropriate tissue cultures in revision surgery for prosthetic joint infection of the shoulder
- ≥ 4 tissue samples
- held for at least 14 days on aerobic, anaerobic and broth media
83
What are the indications for each surgical treatment option of GH arthritis in a young patient?
1. Arthroscopic debridement and capsular release
* Mild OA
* Joint space visible on radiograph
* Minimal osteophyte formation and subchondral sclerosis/cysts
* Osteochondral lesions \< 2cm2
* Concentric joint
2. Biological replacement (Microfracture/ACI/Allo/Autograft)
* Focal, contained chondral lesions with maintained subchondral plate and the lesion is \< 2 cm2 in size
3. Humeral arthroplasty without glenoid treatment
* Young patient with unipolar disease
* Glenoid preserved
4. Humeral arthroplasty with glenoid treatment
* Young patient with bipolar disease
* Ream and run can be used in eccentric glenoids as reaming can create a concentric joint
5. Anatomic TSA
* Severe bipolar disease with intact cuff
* Low demand patient with eccentric or concentric glenoid
6. Corrective osteotomy of glenoid
* Symptomatic, fixed posterior subluxation and posterior glenoid wear
7. Arthrodesis
* End-stage OA in patients with strenuous physical demands (i.e. heavy manual labor)
* Multiple failed surgeries
* Voluntary dislocators
* Failed arthroplasty
* Massive cuff tear with deltoid deficiency
* Severe neurological injury
* Chronic infection
8. rTSA
* Low demand
* Limited preoperative function
* Failed rotator cuff repair or other arthroplasty means
* Rotator cuff arthropathy
84
What are the indications and contraindications for comprehensive arthroscopic management (CAM) of GH arthritis?
[JAAOS 2018;26:745-752]
1. Indications
* Advanced symptomatic GH arthritis
* Young (\<50 yr)
* Active patient
* Desire for joint preservation
* Failed nonsurgical management
2. Absolute contraindications
* Mild GH arthritis
* Nonsurgical treatment not yet attempted
* Incongruous joint space and severe deformity
* Inflammatory glenohumeral arthritis
3. Relative contraindications
* \<2 mm GH joint space
* Severely limited GH PROM (especially IR)
* Large osteophytes
* Bipolar chondral lesions
* Low critical shoulder angle
* Kellgren-Lawrence grade III or IV arthritis
* Walch B2 or C glenoid changes
85
What are the advantages/disadvantages of comprehensive arthroscopic management (CAM) of GH arthritis?
[JAAOS 2018;26:745-752]
Advantages
* Joint preserving
* Retaining native anatomy does not preclude future treatment options
* Delays or avoids arthroplasty
Disadvantages
* Technically demanding procedure
* Additional surgery as patients may require future arthroplasty
* Novel procedure with unknown long-term outcomes
86
What pathologies can be addressed with comprehensive arthroscopic management (CAM) of GH arthritis?
[JAAOS 2018;26:745-752]
1. Synovitis = Synovectomy
2. Adhesions = Débridement
3. Cartilage fraying = Chondroplasty
4. Loose bodies = Loose body removal
5. Goat’s beard deformity = Inferior humeral osteoplasty
6. Axillary nerve impingement and adhesions = Axillary nerve neurolysis
7. Capsular tightness/decreased ROM = Capsular release
8. Subacromial impingement = Subacromial decompression
9. Subcoracoid impingement = Subcoracoid decompression
10. Focal chondral defects = Microfracture
87
What is glenoid dysplasia characterized by?
[JAAOS 2016;24:327-336]
1. Bony deficiency of the posteroinferior glenoid and scapular neck
2. Result of failure of ossification of secondary ossification center
3. Thickened cartilage and hypertrophic labrum found in region of bone deficiency
88
What is the management of glenoid dysplasia?
[JAAOS 2016;24:327-336][JBJS 2016;98:958-68]
1. Asymptomatic
* Nil
2. Symptomatic in absence of arthritis
* Nonoperative
* Operative
* Open or arthroscopic labral repair or capsulorrhaphy
* Glenoid reorientation (glenoplasty)
* Posterior opening wedge osteotomy
* Glenoid augmentation
* Posterior glenoid bone grafting (autograft or allograft)
3. Symptomatic in presence of arthritis
* Nonoperative
* Operative
* Arthroscopic debridement and capsular release (mild to moderate OA)
* Hemiarthroplasty
* Anatomic TSA
* Augmented glenoids
* Eccentric reaming (if \<15° retroversion)
* Bone grafting
* Glenoid osteotomy
89
What is the resultant pathology following chronic shoulder dislocation?
[JAAOS 2008;16:385-398]
1. Osteoporosis of the humeral head
2. Softening of the articular cartilage
3. Adhesion and scarring to adjacent neurovascular structures
4. Rotator cuff tears
5. Humeral head bone defects
6. Glenoid bone defects
90
What is the usual clinical presentation of chronic shoulder dislocation?
[JAAOS 2008;16:385-398]
1. Relatively mild shoulder discomfort
2. Limited ROM but often functional ROM
* Forward elevation and abduction limitation
* IR limited with anterior dislocation
* ER limited with posterior dislocation
91
The treatment of chronic shoulder dislocations are based on what factors?
[JAAOS 2008;16:385-398]
1. Functional limitations
2. Duration of dislocation
3. Size of the humeral head defect
4. Size of glenoid bone defect/erosion
5. Status of the articular cartilage
92
What are the indications for nonoperative management of chronic shoulder dislocations?
[JAAOS 2008;16:385-398]
1. Limited functional demands in patient with minimal pain and can perform ADLs
2. Unacceptable surgical risk (comorbidities)
3. Unable to comply with postoperative rehab
93
When is a closed reduction of a chronic glenohumeral joint indicated?
[JAAOS 2008;16:385-398]
1. \<4 weeks
2. Absence of large humeral head defects
94
Describe the management of a chronic anterior shoulder dislocation by open reduction
[JAAOS 2008;16:385-398]
1. Open reduction
* Deltopectoral approach
* Subscapularis tenotomy
* Anteroinferior capsular release from humerus
* Reduction of humeral head by lateral displacement and internal rotation
* Address humeral head defects
* \<20%
* Immobilization alone
* Anterior soft tissue Bankhart repair
* 20-40%
* Disimpaction and bone grafting
* Indicated when \<3-4 weeks old
* Younger patient
* Allograft
* Younger patient
* Size-matched humeral or femoral head allograft press-fit into defect and fixed with two cancellous screws
* Infraspinatus or GT transfer
* Requires additional posterior approach
* Smaller defects (20-25%) = infraspinatus transfer into defect
* Larger defects = GT transfer
* \>40%
* Allograft
* Younger patient
* Prosthetic
* Older patients
* Consider in smaller defects if remaining cartilage degenerated
* Place in 10-15° more retroversion than standard
3. Address glenoid defects
* \>20-25%
* Coracoid transfer (Latarjet)
* Iliac crest autograft
95
Describe the management of a chronic posterior shoulder dislocation
[JAAOS 2008;16:385-398]
1. Open reduction
* Deltopectoral approach
* Subscapularis management depends on planned procedure
* Transfer – peel off LT
* Allograft or prosthesis – tenotomy
* LT transfer – LT osteotomy
* Reduction of humeral head with external rotation
* Address humeral head defects
* \<20%
* Immobilization alone
* 20-40%
* Disimpaction and bone grafting
* Allograft
* Subscapularis or LT transfer
* \<20% = subscapularis transfer
* 20-40% = LT transfer
* \>40%
* Allograft
* Younger patients
* Prosthetic
* Older patients
* Consider in smaller defects if remaining cartilage degenerated
* Place in 10-15° less retroversion than standard
96
What are the stabilizing structures of the SC joint?
[JAAOS 2011;19:1-7]
1. Costoclavicular (rhomboid) ligament
* Strongest
2. Capsular ligaments
3. Interclavicular ligaments
4. Intra-articular disc
97
Which direction is most common for SC joint dislocations?
[JAAOS 2011;19:1-7]
Anterior dislocation
98
What are the concerning symptoms associated with posterior SC dislocations?
[JAAOS 2011;19:1-7]
1. Difficulty breathing/SOB = compression of trachea or pneumothorax
2. Dysphagia = compression of esophagus
3. Decreased ipsilateral circulation = vascular compression
4. Venous congestion in extremity or neck = vascular compression
5. Numbness or paraesthesia = brachial plexus compression
\*\*\*NOTE – if symptoms present, thoracic or cardiothoracic surgery consult needed
99
What radiographic view is specific for assessing SC joint injuries?
[JAAOS 2011;19:1-7]
Serendipity view - 40° cephalic tilt centred on SC joint
100
What advanced imaging is indicated for better assessment of SC joint injuries?
[JAAOS 2011;19:1-7]
CT scan
101
What is the management of an anterior SC joint dislocation?
[JAAOS 2011;19:1-7]
1. Closed reduction
* Most are unstable after closed reduction
* However an attempt is made because when successful it results in better cosmesis
* Technique
* Sedation or local anaesthetic
* Supine with 3” pad between shoulders
* Posterior pressure applied to medial clavicle
2. Open reduction not indicated
* Risk outweighs benefit
102
What is the management of posterior SC joint dislocation?
[JAAOS 2011;19:1-7]
1. Closed reduction
* Most are stable after closed reduction
* Technique
* Thoracic surgeon available
* Supine with 3” pad between shoulders and arm at edge of bed
* Arm is abducted to be in line with clavicle
* Inline traction is applied with countertraction with a sheet to the torso
* The arm is then extended
* If unsuccessful:
* Grasp clavicle with a sterile towel clip completely around clavicle, with traction applied to arm lift the clavicle anteriorly
2. Open reduction
* Indicated when closed reduction fails due to complications associated with unreduced posterior dislocations
* TOS
* Vascular compromise
* Erosion of medial clavicle into vital structures
* Technique
* Incision parallel to medial clavicle
* Ppreserve anterior capsule
* Reduce the SC joint
* If stable no further intervention
* If unstable:
* Medial clavicle resection and stabilization with repair to capsular ligament and periosteum
* Alternative – reconstruction with semitendinosus graft in figure-of-8
103
What are the characteristic pathoanatomical features of adhesive capsulitis?
[JAAOS 2011;19:536-542]
1. Thickened and tight glenohumeral joint capsule
2. Adhesions obliterating the axillary fold
3. Capsular adhesions to itself and the anatomic neck of the humerus
4. Joint volume is diminished with minimal synovial fluid present
104
What are the pathological features of adhesive capsulitis?
[JAAOS 2011;19:536-542]
1. Chronic inflammatory infiltrate
2. Absence of synovial lining
3. Extensive subsynovial fibrosis
105
What are the 4 stages of adhesive capsulitis?
[JAAOS 2011;19:536-542]
Stage 1 – Preadhesive stage
* Clinical
* Pain but full ROM
* Pathology
* Fibrinous inflammatory synovitic reaction
Stage 2 – Adhesive stage
* Clinical
* Pain and mild loss of ROM
* Pathology
* Synovitis, proliferation, early adhesions
Stage 3 – Maturation
* Clinical
* Less pain, more ROM loss
* Pathology
* Less synovitis, more fibrosis
* Axillary fold obliterated
Stage 4 – Chronic
* Clinical
* Severe loss of ROM, pain minimal
* Pathology
* Fully mature adhesions
106
What are the associated conditions/risk factors for adhesive capsulitis?
[JAAOS 2011;19:536-542]
1. Female
2. Age 40-60
3. Nondominant arm
4. Sedentary vocation
5. Systemic conditions
* CVD, CVA, MI, thyroid disease, breast cancer treatment, diabetes
* Diabetes is associated with:
* Worse prognosis
* Greater need for surgery
* Suboptimal results
107
In adhesive capsulitis, what are the findings on clinical examination?
[JAAOS 2011;19:536-542]
1. Rotator cuff strength normal
2. **Mechanical block to PROM (hallmark)**
* Best assessed with ER with arm at side
108
What is the management of adhesive capsulitis?
[JAAOS 2011;19:536-542]
1. Nonoperative
* Physiotherapy and home exercises
* Gentle progressive stretching
* Intra-articular corticosteroids injection
* Short term reduction in pain with no effect on ROM or long term prognosis
2. Operative
* Indication:
* Failure of nonoperative after 6 month trial
* MUA
* ER
* Elevation above patients head
* Reduce elevation to 90° and max IR
* (Correct ER→Elevation→IR)
* Arthroscopic capsular release (preferred)
* Advantage
* Controlled capsular release with less risks
* Release:
* Anterior capsule
* Rotator interval
* Axillary recess to 6 o’clock position
* Consider posterior capsule release if loss of IR after anterior release
3. Postoperative
* Immobilize arm in 90° abduction and ER for postoperative night 1
* Exercises begin POD#1
* Arm kept in abducted position for POD1+2
* Sleep in abduction for 2 weeks
* Outpatient therapy continued until full motion restored and maintained
109
What are the risk factors for proximal humerus nonunion?
[JAAOS 2013;21:538-547]
1. Metaphyseal comminution
2. Surgical neck translation \>33%
3. 2-part surgical neck fracture
4. Smokers
5. Significant medical comorbidities (diabetes, obesity, osteopenia)
110
When is a fracture of a long bone considered nonunion?
[JAAOS 2013;21:538-547]
1. Lack of healing 6-9 months following injury
* Delayed union after 4 months
2. No interval healing on two consecutive radiographs 6-8 weeks apart
111
When is surgery recommended for nonunion of the proximal humerus or humeral shaft?
[JAAOS 2013;21:538-547]
3-6 months post-injury if an impending nonunion is expected
112
What are the treatment options for proximal humerus nonunions?
[JAAOS 2013;21:538-547]
1. Nonoperative
* Indications
* Medical comorbidities that preclude surgery
* Minimal pain and functional losses
2. Operative
* Osteosynthesis with proximal humerus locking plate and bone graft
* Indications:
* Good bone quality
* Viable humeral head
* Absence of medial calcar comminution or osteopenia
* Osteosynthesis of GT or LT nonunions
* Construct for large fragments and viable cuff:
* Lag screws and/or buttress plates with bone graft
* Construct for comminuted fragments:
* Tension band techniques
* Transosseous suture fixation
* Suture anchor with bone graft
* Fixed angle locking plate with fibular strut allograft
* Indications:
* Compromised medial calcar support due to comminution or osteopenia
* Hemiarthroplasty, TSA, rTSA
* Indication for rTSA:
* Humeral head collapse and/or dysfunctional RTC
* Rotator cuff atrophy
* Severe tuberosity malunion or resorption
* Indication for TSA:
* Associated GH arthritis and intact rotator cuff
113
What are the risk factors for humeral shaft nonunions?
[JAAOS 2013;21:538-547]
1. Transverse fractures \> short oblique fractures
2. Proximal diaphysis location
* Greater deforming forces from deltoid and pec major
* Interposed muscle and long head of biceps
* Difficulty with immobilization
114
What are the treatment options for humeral shaft nonunions?
[JAAOS 2013;21:538-547]
1. Nonoperative
* Indications
* Medical comorbidities precluding surgery
* Asymptomatic nonunions or pseudoarthroses with low functional demand
2. Operative
* ORIF with compression plating and autogenous bone grafting
* Indications:
* Standard of care in absence of prior surgery
* Technique:
* Anterolateral approach
* Identify radial nerve between brachialis and BR
* Perform neurolysis if entrapped in scar
* Debride and decorticate fracture ends
* **Broad 4.5mm compression plate** with 6-8 cortices above and below fracture site
* Augment with ICBG (or DBM)
* Dual orthogonal plating
* Indications:
* Fixation limited by a short proximal or distal fragment
* Poor metaphyseal bone quality
* Cortical strut allograft
* Indications:
* Severe osteopenia
* Cortical allograft placed intramedullary or along medial humerus
* Fixed with lateral compression plate and screws that cross the strut gaining additional cortical fixation
115
What is the origin and insertion of the teres minor?
1. Dorsal side of the lateral border of the scapula
2. Posteroinferior greater tuberosity
3. Lies posterior to the rotator cable and is not associated with it
116
What is the innervation of the teres minor?
Posterior branch of the axillary nerve
117
What does the posterior branch of the axillary nerve supply?
1. Teres minor
2. Superolateral brachial cutaneous nerve
3. Posterior deltoid
118
What is the function of the teres minor in the native shoulder?
1. Dynamic stabilizer
2. External rotator
119
What effect does a supraspinatus and infraspinatus tear have on the teres minor?
Increased activity and subsequent hypertrophy as it must counteract the subscapularis
120
The infraspinatus and teres minor contribute to shoulder ER, at what shoulder position does the teres minor become more active and contribute more to ER rotation moment?
Higher levels of abduction
121
What special tests are described to evaluate the teres minor?
[J Am Acad Orthop Surg 2018;26:150-161]
1. Patte test
* Patients shoulder and elbow are flexed 90° and forearm is parallel to floor
* Patient externally rotates against resistance
* Positive = weakness
2. Hornblower sign
* Complete inability to externally rotate with shoulder and elbow flexed 90° and forearm is parallel to floor
3. Dropping sign
* Patient has arm at side with elbow at 90°, arm is externally rotated 45°
* Positive = arm falls back to neutral position
* Unable to maintain ER
4. External rotation lag sign
* Patients elbow is flexed 90° and elevated 20 in the scapular plane
* Examiner externally rotates to 5 short of maximum
* Positive = lag measuring \>10
* Lag \>30° substantially related to a lesion involving the teres minor
5. Hertle drop sign
* Patients shoulder and elbow are flexed 90°
* Positive = forearm drops
122
What is the most accurate test to evaluate the teres minor?
[J Am Acad Orthop Surg 2018;26:150-161]
External rotation lag sign with a lag \>40°
* 100% sensitivity
123
What is the Walch classification system for evaluating the presence of teres minor atrophy on CT or MRI?
[J Am Acad Orthop Surg 2018;26:150-161]
1. Normal
* Thickness of the muscle is equal to half the width of the glenoid
2. Hypertrophic
* Thickness is greater than the width of the glenoid
3. Atrophic
* Muscle belly is thin from anterior to posterior
4. Absent
* Muscle is not identifiable
124
What is the incidence of isolated teres minor tears?
[J Am Acad Orthop Surg 2018;26:150-161]
Never, always occur in conjunction with infraspinatus tear
125
The presence of a functioning teres minor is a positive prognostic factor for which 2 surgical procedures?
[J Am Acad Orthop Surg 2018;26:150-161]
1. Latissimus dorsi transfer for massive irreparable posterosuperior cuff tears
2. rTSA
126
In the presence of a nonfunctional teres minor, what additional procedure can be considered to improve outcomes in rTSA?
[J Am Acad Orthop Surg 2018;26:150-161]
L’Episcopo technique
* Latissimus dorsi and teres major transfer
* Transfer from anterior humerus to posterolateral
* Change from internal rotators to external rotators
127
What is the quadrilateral space syndrome?
1. Compression of the axillary nerve in the quadrilateral space
* Usually due to fibrotic bands or posterior humeral circumflex artery compression
2. Presents with shoulder pain, paraesthesia and tenderness over the quadrilateral space
3. Weakness of posterior deltoid and teres minor
