The document discusses shoulder arthroplasty, covering its historical development, anatomy, biomechanics, and prosthesis design. It details various procedures including hemiarthroplasty, total shoulder arthroplasty, and reverse shoulder arthroplasty, along with indications, contraindications, and potential complications. Complications such as glenoid and humeral loosening, instability, rotator cuff failure, and infection are highlighted, emphasizing the importance of careful surgical technique and postoperative management.

1. SHOULDER ARTHROPLASTY
BY:Dr.NIHARIKA
MODERATOR:Dr.VENKATESWAR REDDY

2. HISTORICAL PERSPECTIVE
• 1893, when a French surgeon, Péan, substituted a platinum and
rubber implant for a glenohumeral joint destroyed by tuberculosis
• In the early 1950s, Neer introduced a humeral head prosthesis that he
planned to use for complex shoulder fractures
• In 1974, the Neer II humeral prosthesis, which was modified to
conform to a glenoid component, was introduced
• In the early 1990s, Paul Grammont introduced an improved design of
a semiconstrained shoulder replacement

3. ANATOMY AND BIOMECHANICS
• The anatomy of the shoulder joint permits more mobility than any
other joint in the body.
• The glenohumeral joint depends on the static and dynamic stabilizers
for movement and stability,
• especially the rotator cuff, which not only stabilizes the glenohumeral
joint while allowing greater freedom of motion but also fixes the
fulcrum of the upper extremity against which the deltoid can contract
and elevate the humerus

7. PROSTHESIS DESIGN
• Most current systems are modular with varying humeral head
diameters and neck lengths to allow more accurate coverage of the
cut surface of the humeral neck and improve the ability to establish
correct position of the joint line
• Anatomic positioning of the humeral head prosthesis is best done
with an eccentric locking position of the Morse taper, which allows
adjustments to the variable medial offset and any posterior offset.
• Most stems can be inserted with a press-fit or cemented technique

8. • Cemented all-polyethylene components remain the most frequently
used glenoid components
• Translation in a perfectly congruent joint may have a potential for
localized wear and loosening (rocking-horse effect).

9. PREOPERATIVE PLANNING
• Standard radiographs include anteroposterior views with a 40-degree
posterior oblique view in neutral position and internal and external
rotation and an axillary lateral view
• planning includes careful evaluation of the radiographs and the CT
scans.
• CT gives a clear view of the glenoid bone stock and wear pattern
• optimize implant position, size, and range of motion is an evolving
area of investigation.

10. • MRI can be a useful preoperative planning tool in this population
• MRI also typically demonstrates advanced cartilage degeneration and
may show numerous other findings, including thinning of the
subscapularis and degenerative changes .

11. POSITION AND APPROACH

12. HEMIARTHROPLASTY
• A shoulder hemiarthroplasty is a procedure in which the humeral
articular surface is replaced with stemmed humeral component.
• INDICATIONS
(1) the humeral joint surface is rough, but the cartilaginous surface of
the glenoid is intact, and there is sufficient glenoid arc to stabilize the
humeral head;
(2) there is insufficient bone to support a glenoid component;
(3) there is fixed upward displacement of the humeral head relative to
the glenoid (as in cuff tear arthropathy or severe rheumatoid arthritis)

13. (4) there is a history of remote joint infection; and
(5) heavy demands would be placed on the joint (anticipated heavy
loading from occupation, sport, or lower extremity paresis).
• CONTRA INDICATIONS
1.recent sepsis,
2.a neuropathic joint,
3.a paralytic disorder of the joint,
4. deficiencies in shoulder cuff and deltoid muscle function, and
5. lack of patient cooperation

15. • The goal of hemiarthroplasty is restoration of the humeral articular
surface to its normal location and configuration.
• Care should be taken to avoid a “big head” humeral prosthesis that
can “overstuff ” the joint
• Good deltoid function and an adequate coracoacromial arch are key
to successful hemiarthroplasty in patients with severe rotator cuff
arthropathy

17. TOTAL SHOULDER ARTHROPLASTY
• is a procedure used to replace the diseased or damaged ball and socket joint
of the shoulder with a prosthesis made of polyethylene and metal
components.
• The primary indication for total shoulder arthroplasty is endstage
glenohumeral joint degeneration with an intact rotator cuff.
• osteoarthritis,
• rheumatoid arthritis,
• osteonecrosis,
• posttraumatic arthritis,
• and capsulorrhaphy arthropathy.

18. • Contraindications to shoulder arthroplasty include
• active or recent infection
• and irreparable rotator cuff tears.
• Paralysis with complete loss of function of the deltoid is also a
contraindication.
• Debilitating medical status and uncorrectable glenohumeral
instability are additional contraindications to shoulder arthroplasty

23. REVERSE SHOULDER ARTHROPLASTY
• The glenohumeral instability resulting from Rotator cuff arthropathy is
manifested as proximal migration of the humerus relative to the
glenoid
• resulting in erosion of the superior glenoid and the caudal surface of
the acromion.
• Rotator cuff tears have been implicated in early glenoid component
loosening in total shoulder replacements, and irreparable tears are
generally considered a relative contraindication to prosthetic glenoid
resurfacing.

25. • Contraindications include
loss or inactivity of the deltoid and
excessive glenoid bone loss that would not allow secure implantation
of the glenoid component

26. • Biomechanically, the reverse prosthesis works by changing the
direction of pull of the deltoid muscle.
• With standard prostheses, absence of the rotator cuff allows the
humeral head to subluxate superiorly during deltoid muscle
contraction.
• The reverse prosthesis corrects this abnormal vector by moving the
center of rotation of the arm medially and distally and reestablishing
a fulcrum around which the deltoid can pull to restore forward
elevation

30. GLENOID BONE LOSS

32. COMPLICATIONS
• The overall complication rate after total shoulder arthroplasty is
estimated to be approximately 15% .
• INTRAOPERATIVE COMPLICATIONS
Periprosthetic fracture
periprosthetic fractures of the humerus or glenoid are caused by errors
in surgical technique, such as 1.inadvertent reaming, 2.overzealous
impaction, 3.or manipulation of the upper extremity during exposure of
the glenoid

33. Humeral component malpositioning
Nerve injury :
Most commonly intraoperative axillary nerve injury or radial nerve
injury due to humerus shaft fracture

34. • POSTOPERATIVE COMPLICATIONS
1.GLENOID LOOSENING:
Symptomatic loosening of glenoid or humeral components is the most
common problem encountered in total shoulder arthroplasty
A shift in the position of the glenoid component or circumferential
radiolucent lines at least 1.5 mm wide are evidence of a loose glenoid
component.
Injection of the cement under pressurization provided by a syringe and
application of cement on the back side of the glenoid component has
been reported to improve glenoid component

35.  If glenoid loosening is present in an asymptomatic patient, only
observation is indicated;
 however, if loosening is present in a patient who has symptoms of
pain, decreased range of motion, and functional disability, further
investigation is warranted to determine if implant replacement is
appropriate.
A painful “clunking” sensation with forward elevation of the arm has
been described as a sign of symptomatic glenoid loosening

36. 2.HUMERAL LOOSENING:
 diagnosed by a change in implant position or progression to
circumferential radiolucent lines.
3.INSTABILITY
Instability is the second leading cause of complications associated
with shoulder arthroplasty
 Approximately 80% of instability complications after total shoulder
arthroplasty involve anterior or superior instability

37. Anterior instability most commonly is associated with subscapularis
failure, glenoid anteversion, malrotation of the humeral component,
or anterior deltoid dysfunction.
Progressive superior migration of the humeral head has been
reported in association with dynamic muscle dysfunction, attenuation
of the supraspinatus, failed rotator cuff repairs, and frank rupture of
the rotator cuff.
Posterior instability has been attributed most often to malpositioning
of the components but may be multifactorial as well..

38. Posterior glenoid erosion with excessive component retroversion and
soft-tissue imbalance has been implicated in the development of
posterior instability
Inferior instability is related to the loss of normal humeral height and
is most common after hemiarthroplasty for proximal humeral
fractures.
Removal of too much of the proximal humerus, with resultant inferior
placement of the humeral head, can lead to inferior instability

39. 4.PERIPROSTHETIC FRACTURE
prevalence of postoperative periprosthetic
humeral shaft fractures ranges from 0.5% to 2%

40. 5.ROTATOR CUFF FAILURE
Rotator cuff failure is the fourth most common complication after
shoulder arthroplasty, with a reported incidence of 1% to 2%
Rupture of the subscapularis tendon is involved in most rotator cuff
tears.
Factors reported to be associated with postoperative tears of the
subscapularis tendon include multiple operations, overstuffing of the
joint, overly aggressive therapy involving external rotation during the
early postoperative period, and tendon compromise by lengthening
techniques

41. Preoperative fatty infiltration of the infraspinatus and a glenoid
component placed in superior tilt are risk factors for subsequent
rotator cuff failure
Large tears cause superior subluxation and eventual loosening of the
glenoid component from compression forces on the superior rim of
the glenoid (the so-called rocking horse glenoid)

42. 6.DELTOID DYSFUNCTION:
Deltoid muscle dysfunction caused by axillary nerve injury or
detachment of the deltoid muscle can result in a catastrophic loss of
shoulder function.
7.HETEROTOPIC OSSIFICATION:
Heterotopic ossification has been noted to occur after shoulder
arthroplasty in 10% to 45% of patients.
 Bridging heterotopic bone of the glenohumeral joint or
glenoacromial space can occur in extreme situations

43. 8.INFECTION:
Infection is rare after both primary anatomic and reverse total
shoulder arthroplasty.
male sex and younger age at the time of arthroplasty are risk factors
Propionibacterium acnes is the most commonly isolated organism
Intraoperative findings of humeral loosening, turbid fluid, and
membrane formation all correlate with the likelihood of a positive
culture for P. acne

44. 9.STIFFNESS
.Postoperative stiffness, typically manifested by loss of forward
elevation or external rotation, usually results from oversizing of
components, shortening or overtightening of the subscaularis, or
insufficient rehabilitation

45. 10.SCAPULAR NOTCHING

49. THANK YOU