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Glenoid in Total Shoulder Replacement
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Discussion about the glenoid pathology in shoulder arthritis and its management in anatomic shoulder replacement. What size implant, whether all poly or a metal backed.
12. Total Shoulder Replacement compared with humeral head replacement for
treatment of primary glenohumeral osteoarthritis: A systematic Review
Radnay CS, et al: J Shoulder Elbow Surg. 2007 Jul-Aug;16(4):396-402
•Clinical studies published between 1966 and 2004 that reported on shoulder
replacement for primary glenohumeral osteoarthritis
•23 studies, with a total of 1952 patients and mean follow-up of 43.4 months
(range, 30-116.4 months).
•Compared to Hemi; TSR had greater
•pain relief (P < .0001)
•forward elevation (P < .0001)
•gain in forward elevation (P < .0001)
•gain in external rotation (P = .0002)
•patient satisfaction (P < .0001)
•6.5% vs 10.2% revision rate (TSR vs Hemi)
•1.7% revision for polyethylene wear
13. Total shoulder arthroplasty versus hemiarthroplasty for glenohumeral
arthritis: A systematic review of the literature at long-term follow-up
Bekerom et al: Int J Shoulder Surg. 2013 Jul-Sep; 7(3): 110–115.
• Hemi vs TSR since 1990, minimum 7 yrs follow up
• 18 studies, 1958 patients, 2111 shoulders (all level 4)
• 328 hemi, 1783 TSR
• Revision rate 7% in TSR, 13% in Hemi (p< 0.001)
• Any complication: 12% TSR, 8% Hemi (p = 0.065)
• Greater increase in range of movements
• Greater improvement in pain (5.5 vs 4.2)
14. Complications
Bohsali KI, et al: Complications of total shoulder arthroplasty. J Bone Joint Surg Am 88:2279-2292, 2006
•33 studies minimum 2 yr follow up (mean 5.3 yrs)
• Glenoid Loosening - 39%
• Superior Instability - 19%
• Periprosthetic Fracture - 11%
• Rotator Cuff Tear - 7.7%
• Humeral Loosening - 6.5%
• Other Instability, Nerve Injury & Infection - 10%
16. Approach
•Beach Chair / Deck Chair
• Reclined about 40 / 45 degrees
• Shoulder pulled away from table
• Make sure imaging can be performed before
draping
34. Glenoid Height
• Defined as the distance from the most superior and
inferior points on the glenoid.
• Mean Height: 35 - 39 mm
• Checroun et al: 412 cadaveric scapulae
• Mean height: 37.9 mm (31.2 - 50.1)
• Iannotti et al: 70 shoulders, avg age 75
• Mean Height: 39 mm (30 - 48)
35. • Churchil et al: 344 cadaveric scapulae
• Male: 37.5 mm (30.4 - 42.6)
• Female: 32.6 mm (29.4 - 37)
• Mallon et al: 28 cadaver
• Male: 38 mm (33 - 45)
• Female: 36.2 mm (32 - 43)
Churchill et al: No difference in glenoid
height between specimens from white and
black patients
36. Glenoid Width
• Distance from the most anterior
and posterior points on the glenoid
• Common shape is ‘PEAR’ but can be
oval or elliptical
• Checroun et al: 412 cadavers
• 71% had pear shaped, rest elliptical
• Upper Width & Lower Width
37. • Iannotti et al:
• Mean Upper Width: 23 mm (18 - 30)
• Mean Lower Width: 29 mm (21 - 35)
• Kwon et al: 26.8 mm (22 - 35)
• Mean articular surface area:
• Males: 5.79 cm2
• Females: 4.68 cm2
38. Churchill et al: No difference in glenoid
height between specimens from white and
black patients
• Churchill et al:
• Males: 27.8 mm (24.3 - 32.5)
• Females: 23.6 mm (19.7 - 26.3)
• Mallon et al:
• Males: 28.3 mm (24 - 32)
• Females: 23.6 mm (17 - 27)
39. Glenoid Inclination
• The slope of the glenoid articular surface
along the superior - inferior axis
• Wide variation
• Superior Inclination:
• Males: Avg 4o
( 7o
to -15.8o
)
• Females: Avg 4.5o
(1.5o
to -15.3o
)
40. Glenoid Version
• Is the angular orientation of the axis of the
glenoid articular surface relative to the long
(transverse) axis of the scapula
• Average 2 - 9 degrees retroversion
• Churchill et al:
• Mean retroversion: 1.2 (9.5 anteversion - 10.5 retroversion)
• Men slightly more retroverted than women
41. Measuring Glenoid Version
• Conventional Radiographs vs CT scan
• Nyffeler et al:
• 50 patients, 25 each for instability & OA
• CT measured 3o
retroversion ( 7o
- 16o
)
• Plain radiograph - over estimated in
86% cases
• Mean difference: 6.5o
(0o
to - 21o
)
43. Glenoid Design
• Dilemma
• All Poly vs Metal Back
• Pegged vs Keeled
• Flat vs Curved Back
• Thickness of Cement
44. •Boileau et al:
• 39 patients, prospective study
• Function better in cemented - but not
clinically significant
• Radiographic lucent lines
•25% vs 85% uncemented vs cemented
• Revision Surgery 1% vs 20%
45. •Wallace et al:
• 32 cemented vs 26 uncemented
• 5 yr follow up
• No significant clinical difference
• 5 revisions in uncemented vs 3,
but not for loosening
46. •Martin et al:
• 140 uncemented glenoid
• 7.5 year follow up
• 16 (11.4%) failed clinically
• 38% radiolucent lines
• 16 had broken screws
• 10 yr predicted survival = 85%
• Factors
• Male Gender,
• Post op pain
• Presence of radiolucent lines
47. •Taunton et al:
•83 TSA with metal back
uncemented glenoid
•40% radiographic loosening
•25% siginficant polyethylene
wear
•5 yr survival = 87%
•10 yr survival = 78.5%
48. Pegged vs Keeled Cemented
• Lazarus et al:
• 328 patients, 39 keeled, 289 pegged
• Pegged glenoid - significantly better seating & fewer radiolucencies
• Gartsman et al:
• 29% keeled & 5% pegged glenoids had radio lucent lines at 6 weeks
• Nuttall et al:
• RSA study on 20 shoulders
• Increased translation & rotation in keeled vs pegged
49. Flat vs Curved Back Cemented
•Szabo et al:
• 66 TSA in 63 patients
• 65% vs 26% perfect seated glenoid in curved back
• Radiolucency scores were worse in flat back
50. Flat vs Curved Back Cemented
• Anglin et al:
• Curved back glenoids are associated with nearly 50% less
distraction than flat back
• Iannotti et al:
• Finite Element Analysis in 0o
& 20o
retroversion
• Peak strains greater in flat back than curved back
51. • Radial Mismatch
• Difference in the curvature
• Increased conformity = Increased constraints = ? Less Shear
• Less Conformity = Larger translation but low surface area
• No consensus
• Size of prosthesis
52. Terrier et al: JSES, 2006
Influence of glenohumeral
conformity on glenoid stresses
after total shoulder arthroplasty
53. Cement Fixation
•Terrier et al:
• FEA to assess stress in the bone & cement
• 0.5, 1.0, 1.5 mm & 2.0 mm
• 1 mm cement mantle thickness is ideal
54. Cement Fixation
•Nyffeler et al:
• Axial pull out test to assess cement thickness
• 0.1 mm - 0.6 mm
• Threaded pegs better than notched pegs
• Roughened back glenoids better than smooth
56. Assessment of Glenoid Wear
• Plain Radiographs - often suboptimal - axillary view
• Axial CT with 3D reconstruct
• Scalise et al:
• Mean glenoid retroversion: 17o
+/- 2.2o
• Posterior bone loss: 9 +/- 2.3 mm
57. Walch et al: A Morphologic study of the glenoid
in primary glenohumeral osteoarthritis
J Arthroplasty; 1999; 14; 756 - 60
• A: Central Erosion, Head Central