Hemiarthroplasty shlulder

A short brief discussion about shoulder hemiarthroplasty

1. HEMIARTHROPLASTY SHOULDER Dr Anshul sethi PG ORTHOPAEDICS

2. Outline HISTORY. ANATOMY & BIOMECHANICS. PROSTHESIS DEIGNS. PROSTHESIS & ITS FEATURES. INDICATIONS CONTRAINDICATIONS OBJECTIVE CASE DISCUSSION SURGICAL APPROACH. COMPLICATIONS.

3. History 1 st SHOULDER ARTHROPLASTY French surgeon, Jules Emil Péan , substituted a platinum and rubber implant for a gleno-humeral joint destroyed by tuberculosis. In 1950s, Neer introduced a humeral head prosthesis for complex shoulder fractures. In 1951, he reported his initial results of replacement of the humeral head with an unconstrained cobalt-chromium alloy ( Vitallium ) prosthesis.

4. ANATOMY AND BIOMECHANICS The anatomy of the shoulder joint permits more mobility than any other joint in the body . Glenohumeral joint depends on the static and dynamic stabilizers for movement and stability, especially the rotator cuff. Articular surface of the humeral head is essentially spherical, with an arc of approximately 160 degrees covered by articular cartilage. The glenoid articular surface radius of curvature is 2 to 3 mm larger than that of the humeral head.

5. Humeral head Retroverted 30° from transepicondylar axis of the distal humerus Glenoid 7° of retroversion to 2 degree of anteversion Humeral neck-shaft angle 130 to 135 degrees

6. Normal position of the glenoid surface in relation to the axis of the scapular body ranged from 2 degrees of anteversion to 7 degrees of retroversion. The superior margin of the humeral head articular surface normally is superior to the top of the greater tuberosity by 8 to 10 mm . ( D TO E ) The distance from the lateral base of the coracoid process to the lateral margin of the greater tuberosity is called the lateral humeral offset.(F TO H) The humeral offset defines the position of the proximal humeral articular surface relative to the humeral shaft. B TO C IS THE HEAD THICKNESS

7. BIOMECHANICS 180° of abduction comes from motion in two joints (2:1 ratio) 120° from the glenohumeral joint 60° from the scapulothoracic joint Abduction requires external rotation Internal rotation contracture they can not abduct > 120

8. STATIC RESTRAINTS GLENOHUMERAL LIGAMENTS GLENOID LABRUM ARTICULAR CONGRUITY AND VERSION NEGATIVE INTRAARTICULAR PRESSURE POSTERIOR CAPSULE

9. Dynamic restraints Rotator cuff muscles Rotator interval Biceps long head Periscapular muscles

10. The distance between the center of the humeral head and the central axis of the intramedullary canal is defined as the humeral head offset and is about 7 to 9 mm medial and 2 to 4 mm posterior.

11. Increasing the humeral head thickness by 5 mm has been shown to reduce the range of motion at the glenohumeral joint by 20 to 30 degrees, whereas decreasing the thickness by 5 mm can diminish motion. Replacement of the anatomical humeral head size and position aims to restore normal shoulder biomechanics.

12. PROSTHESIS DESIGN Based on NEER II implant many modular designs were developed to impove implant fixation and durability . Modularity allows a better fit for individual patients because various stem and head sizes can be “mixed and matched” to an individual’s anatomy. Most stems are made of cobalt-chrome alloy, have proximal porous ingrowth coating, and have proximal fins. (A fin is a thin component or appendage attached to a larger body or structure) for rotational stability.

13. Center of the humeral head was 2.6 mm posterior and 6.9 mm medial to the center of the humeral shaft . Anatomical 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. Postoperative kinematics after total shoulder arthroplasty do not mimic those of the native shoulder

14. Prosthetic head should be within 4 mm of the original humeral head thickness.(to prevent overstuffing of joint) Most stems can be inserted with a press-fit or cemented technique. Glenoid part should have an increased radius of curvature compared with the humeral head (2 to 6 mm larger) to allow translation during movement and to decrease edge loading in order to prevent rocking –horse effect (damage to articular cartilage or glenoid loosening in TSA)

15. ROCKING HORSE EFFECT Eccentric loading of the glenoid caused by superior migration of the humeral component has been cited as a cause of glenoid loosening. Association between glenoid component loosening and irreparable rotator cuff tears.

16. DEVELOPMENT IS SHOULDER ARTHROPLASTY PROSTHESIS UNCONSTRAINED NEER II (DESIGNED TO REPRODUCE NORMAL ANATOMY) CUP ARTHROPLASTY (CAN BE OF METAL ,SILASTIC CUP BIPOLAR (MORE MOTION WITH LESS STRESS ON GLENOID) NEER TYPE (LESS CONSTRAINT AND BETTER SOFT TISSUE BALANCING) BIPOLAR (DEAL WITH EXTENSIVE ROTATER CUFF DEFICIENCY)

17. 2. SEMICONSTRAINED DESIGNED AFTER NATURAL ANATOMY (DANA)- they have hooded glenoid ENGLISH-MACNAB ( uncemented design with deep glenoid) CONSTRAINED BALL AND SOCKET TYPE REVERSE BALL AND SOCKET TYPE

18. INDICATIONS OF HEMIARTHROPLASTY SHOULDER END STAGE JOINT DEGENRATION (predominant) MASSIVE LONG STANDING ROTATER CUFF TEAR (CUFF TEAR ARTHROPATHY) NEER CLASSIFICATION TYPE 3 AND 4 PROXIMAL HUMERUS FRACTURES AVASCULAR NECROSIS OF HEAD

19. MATSEN ET AL Listed INSICATIONS OF hemi arthroplasty Humeral joint surface is rough but cartillegnous surface of glenoid is intact Insufficient bone to support glenoid component Fixed proximal migration of humeral head as in rotater cuff arthropathy Remote joint infection Heavy occupational demands

20. CONTRAINDICATIONS Recent sepsis Neuropathic joint Deltoid muscle deficient Paralytic disorder

21. Proximal humeral fractures account for 4% to 5% of all fractures ? ORIF ? Hemi ? RSA Complex fractures

22. PREOPERATIVE PLANNING Routine Blood Investigations.(CBC,ESR,CRP) X-rays. MRI. (in case of glenohumeral degentration ) CT(3D). Rule out sp.bacteria .(Aspiration and culture of glenohumeral joint fluid, holding the culture for at least 14 days to isolate Propionibacterium acnes ) TEMPLATING

23. Computed tomography Excellent picture of the patient’s glenoid bone stock and the pattern of glenoid wear. precisely show the bony deformities and defects before surgery. The role of preoperative planning based on three- dimensional CT scans to optimize implant position, size, and range of motion

24. MRI It is genrally done in cases of gleno-humeral arthritis Thinning of the subscapularis and degenerative changes in the joint. -Rotator cuff status. -Increased capsular volume posteriorly &capsular contraction anteriorly. Precollapse osteonecrosis, MRI is useful for visualizing the area of dead bone and is often the best tool to make the diagnosis.

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26. OBJECTIVE ABOLISH PAIN arising from the pathological joint Restore functional range of motion

27. CASE PATIENT MOHIT BISHT 35 YEAR OLD MALE PRESENTED TO EMERGENCY WITH A/H/O RTA (SLIP FROM BIKE) FOLLWED BY COMPLAIN OF PAIN , SWELLING AND DEFORMITY IN LEFT SHOULDER INABILITY TO MOVE LEFT SHOULDER DIAGNOSED AS FRACTURE PROXIMAL HUMERUS LEFT SIDE (NEER CLASSIFICATION TYPE 3 ) A.O CLASSIFICATION (11 C)

28. PRE OP X RAY

29. CT IMAGES

30. PATIENT MANAGED WITH MODULAR BIPOLAR CEMENTED HEMIARTHROPLASTY LEFT SHOULDER OTHER TYPE OF HEMIARTHROPLASTY : MODIFIED HEMIARTHROPLASTY: INTERPOSITION ARTHROPLASTY AND GLENOIDPLASTY (REAM AND RUN) RESURFACING HEMIARTHROPLASTY

31. SURGICAL STEPS OF HEMIARTHROPLASTY SHOULDER Place the patient in the beach chair position to allow positioning of the patient at the top and edge of the table . Prepare the arm and drape it widely Make an incision anteriorly, approximately one-third to halfway between the coracoid and the lateral aspect of the acromion Open the deltopectoral interval and allow the cephalic vein to fall medially. Perform subdeltoid , subcoracoid , and subacromial releases to release the proximal humerus

32. perform a biceps tenodesis before incising the subscapularis . A figure-of-eight stitch is placed between the biceps and pectoralis major tendons. The biceps is then divided and the proximal portion is later resected before making the humeral head osteotomy. Incise the subscapularis 1 cm medial to the lesser tuberosity. Place two retention sutures in the subscapularis to be used as traction sutures Incise the rotator interval, directing the cut medially toward the glenoid. Gently externally rotate, adduct, and extend the arm to deliver the humeral head up and out of the glenoid fossa

33. REMOVE the fractured head with osteotome and hammer Using broach and box reamer medullary cavity is reamed to appropriate size taking care of retroversion. Inspect the glenoid to confirm there is enough glenoid cartilage to provide an adequate bearing surface for the metal humeral head. check the humeral trial stem to ensure it is seated securely within the humeral canal. If so, tap the component stem into position, taking care to keep the stem in 30 degrees of retroversion. place a cement restrictor or a cortical bone plug from the resected humeral head 2 cm inferior to the tip of the prosthesis And place appropriate stem.

34. Trial humeral head and reduce the glenohumeral joint using internal rotation and gentle traction. With the arm in neutral rotation, check the height of the humeral head to confirm anatomic reconstruction check the version to confirm that the humeral head rests directly across from the glenoid. (With a thumb on the lesser tuberosity, push the humeral head posteriorly and then release it: 50% posterior excursion with immediate “bounce back” of the humeral head is optimal)

35. thoroughly clean the Morse taper, impact the humeral head into position, and reduce the joint for the final time. tight closure of the rotator interval and the subscapularis with heavy nonabsorbable suture and supraspinatous keeping bicep tendon as guide AFTER FIXING THE TUBEROSITY Place drain and do closure in layer Apply shoulder immoblizer .

36. POST OP X-RAY

37. POST OP REHABILITATION

38. COMPLICATIONS INTRAOPERATIVE Axillary nerve injury Periprosthetic fracture Malpositioning of prosthesis POST OPERTIVE COMPLICATIONS humeral stem loosening instability rotater cuff failure ; deltoid muscle dysfunction infection tuberosity migration/nonunion/ malunnion Stiffness

39. STUDIES COMPARING ORIF VS HEMI Bastian and Hertel : ORIF vs Hemi similar functional results & patient satisfaction. ORIF with preservation of the humeral head should be considered when an adequate reduction and stable conditions for revascularization can be obtained. Hemiarthroplasty is a viable alternative for patients with osteopenic bone and/or a comminuted fracture. Bastian JD, Hertel R. Osteosynthesis and hemiarthroplasty of fractures of the proximal humerus: outcomes in a consecutive case series. J Shoulder Elbow Surg. 2009;18:216-9

40. Boileau P, Walch G, Krishnan SG. Tuberosity osteosynthesis and hemiarthroplasty for four-part fractures of the proximal humerus. Tech Shoulder Elbow Surg. 2000;1:96-109.

41. Krishnan et al. : using ‘Gothic arch’ technique reported 88% of the tuberosities healed anatomically. The mean active anterior elevation was 129˚, and pain scores averaged 1.2 points on a 10-point scale. Krishnan SG, Bennion PW, Reineck JR, Burkhead WZ. Hemiarthroplasty for proximal humeral fracture: restoration of the Gothic arch. Orthop Clin North Am. 2008;39:441-50,

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