Total Elbow Arthroplasty - Shoulder & Elbow

summary
- Total Elbow Arthroplasty (TEA) is an increasingly used motion-preserving modality for the treatment of many debilitating elbow pathologies.
- Primary indications include rheumatoid arthritis, post-traumatic arthritis, and intra-articular distal humeral fractures in the elderly with poor bony quality.
- Semiconstrained implants have the best longevity and most optimal functional outcomes.

Epidemiology
- TEA for trauma is one of the fastest-growing indications

Etiology
- Forms of elbow arthroplasty
  - total elbow arthroplasty
  - hemi elbow arthroplasty
    
    radiocapitellar
    
    distal humeral
  - ulnohumeral distraction & interpositional arthroplasty
  - olecranon fossa debridement
  - radial head arthroplasty

Indications
- Indications
  - rheumatoid arthritis (RA)
    
    indication
    
    10-20% of patients with RA will have arthritic changes in the elbow
    
    TEA considered for Larsen stages 3 to 5 with:
    
    functional loss
    
    pain
    
    instability
    
    ideally, patient should be older than 65 years old
    
    outcomes
    
    longest survivorship when TEA is performed for RA compared to other indications
    
    most reliable with advanced, refractory RA
  - primary osteoarthritis (advanced)
    
    indication
    
    patient should be older than 65 years old
    
    mid-arc pain with activity resulting from ulnotrochlear joint cartilage loss
    
    outcomes
    
    10-year implant survival about 80-85% for TEA for primary OA
  - fracture
    
    indication
    
    physiologically elderly patient (e.g., > 70 years) with:
    
    acute complex, unreconstructable intra-articular distal humerus fracture
    
    missed elbow fracture dislocation
    
    poor quality bone
    
    outcomes
    
    faster recovery with more predictable functional outcomes compared to fixation strategies
    
    limitations of lifting weight more than 5 to 10 pounds to avoid implant loosening
  - posttraumatic osteoarthritis (advanced)
  - chronic instability
- Contraindications
  - absolute
    
    active infection (arthrodesis favored)
    
    Charcot joint
  - relative
    
    poor neurologic control of affected extremity
    
    active patient younger than <65 years old
    
    olecranon osteotomy

Implants
- Designs
  - unconstrained or unlinked components
    
    example
    
    Ewald capitello-condylar design
    
    technical aspects
    
    requires competent collateral ligaments and soft tissue envelope
    
    requires good bone quality
    
    outcomes
    
    instability is most common complication (5-10% dislocation)
    
    precise component alignment is required
    
    no proven superiority or clear indication compared with semiconstrained/linked
  - semiconstrained or linked components
    
    examples
    
    Coonrad-Moorey design
    
    technical aspects
    
    "sloppy hinge" allows for some varus-valgus and rotational laxity
    
    reduces stress on bone-cement interface, which reduces incidence of component loosening
    
    outcomes
    
    best results of all the designs
    
    complication of early humeral loosening with designs without an anterior flange
  - constrained
    
    example
    
    Dee design
    
    technical aspects
    
    rigid hinged design
    
    theoretically most stable design (versus unlinked)
    
    outcomes
    
    highest loosening rates compared to semiconstrained and unconstrained designs
- Design pearls
  - component stems (ulna and humerus) have improved fixation and reduced loosening
  - humeral component extracortical anterior flange resists posteriorly directed and rotational forces
  - radial head not needed for stability in linked TEA designs
    
    radial head often debrided or resected in RA, due to mechanical symptoms or pain

Key Technical Concepts
- Preoperative care
  - clinical evaluation
    
    age > 65
    
    low demand patient
    
    able to comply with post-operative weight-bearing restriction (none do so be careful who you operate on)
    
    medical optimization
  - imaging
    
    standard radiographs
    
    AP and lateral views of elbow
    
    assess bone stock
    
    ensure medial and lateral columns are intact
    
    assess canal diameter for implant design
    
    cervical spine
    
    flexion-extension views
    
    rheumatoid arthritis patients
    
    CT scan
- Surgical
  - positioning
    
    supine
    
    arm draped free
    
    requires an assistant to hold the arm over the patients chest
    
    surgeon must take care to avoid the endotracheal tube
    
    lateral decubitus
    
    arm positioned over a bolster
    
    minimizes the need for an assistant to hold arm
    
    decreases the ability to manipulate the arm
  - approach
    
    triceps-reflecting, triceps-splitting, and triceps-sparing
    
    triceps-reflecting (Bryan-Morrey)
    
    triceps reflected from medial to lateral in continuity with the anconeous
    
    triceps re-attached to ulna with nonabsorbable suture through bone tunnels
    
    There can be associated weakness or loss of elbow extension due to the detachment of the triceps brachii insertion from the olecranon.
    
    triceps tongue
    
    raise fascial tongue from olecranon back proximally
    
    release collateral ligaments proximally and distally
    
    can be used for fractures or TEA
    
    triceps-splitting
    
    triceps is longitudinally divided in continuity with forearm fascia over dorsal ulna
    
    triceps can also be split proximally with a V-shaped turndown of the tendon, leaving insertion onto olecranon intact
    
    allows for extensor mechanism lengthening if needed
    
    triceps-sparing
    
    triceps preserved intraoperatively, but exposure can be challenging
    
    medial and lateral borders of triceps are mobilized
    
    best for using TEA to manage acute distal humerus fractures
    
    triceps "on"
    
    direct midline, posterior incision
    
    identify, release and protect the ulnar nerve
    
    release the flexor-pronator mass and medial collateral ligament from medial epicondyle
    
    elevate the triceps off the posterior humerus towards the lateral intermuscular septum
    
    release the common extensors and lateral collateral ligament complex
    
    disarticulate the ulno-humeral joint
    
    technique
    
    bone preparation
    
    preparation of humeral component
    
    resect the olecranon fossa of distal humerus
    
    keep medial and lateral column intact
    
    broaching to appropriate sized component
    
    preparation of ulnar component
    
    resect the olecranon tip of proximal ulna
    
    resect tip of coronoid to avoid impingement on anterior flange which will cause axial pistoning of ulna and loosening
    
    broaching to appropriate sized component
    
    implant insertion
    
    component design
    
    semiconstrained most common
    
    modern cement preparation and technique
    
    humerus component
    
    prepare a wedge-shaped piece of bone for placement behind the humeral flange
    
    maintain component orientation relative to the posterior flat surface of the distal humerus
    
    ulnar component
    
    orient the implant perpendicular to the dorsal flat surface of the olecranon
- Postoperative care
  - early period of immobilization
    
    early motion after TEA is associated with wound complications, instability, and hardware loosening
    
    typically immobilize for 4 weeks after surgery
  - lifelong weightlifting restriction of less than 5-10 lbs

Outcomes
- Rheumatoid arthritis TEA outcomes
  - 10 year survivorship
    
    92.4% rate of survivorship free of revision at 10 years
    
    however very high complication rate (14%)
    
    triceps avulsion
    
    deep infection
    
    periprosthetic fracture
    
    aseptic loosening
- Post traumatic arthritis TEA outcomes
  - 5 year survivorship
    
    most achieve functional ROM and patient satisfaction
    
    high complication rate (27-43%)
    
    high re-operation rate (25%)

                        Complications
                    
                        Aseptic loosening (radiographic 17%, clinical 6%)
                    
                        most common mode of failure for constrained
                    
                        Infection (8%)
                    
                        acute infection (< 30 days)
                    
                        treatment
                    
                        aggressive serial irrigation and debridement and antibiotic bead placement
                    
                        success depends on organism
                    
                        staphylococcus epidermidis is associated with persistent infection because it is an encapsulating organism, and it is best treated with implant removal and IV antibiotic
                    
                        chronic infection
                    
                        treatment
                    
                        two staged reimplantation versus resection arthroplasty in medically ill patients or those with inadequate bone stock.
                    
                        Instability (7-19%)
                    
                        most common mode of failure for semiconstrained
                    
                        Bushing wear (obtain AP xrays and varus/valgus angle of > 10 degrees is concerning)
                    
                        common mode of failure for constrained
                    
                        Wound healing (higher with longterm steroid use)
                    
                        Ulnar neuropathy
                    
                        Triceps insufficiency
                    
                        Bone loss 
                    
                        from multiple revisions, fractures, osteolysis
                    
                        graded based on humeral bone stock
                    
                        treatment
                    
                        up to 8cm of distal humeral loss can be replaced with longer prosthesis with extended anterior flange or endoprosthesis (total humerus)
                    
                        salvage options include flail elbow, amputation, arthrodesis
                    
                        Periprosthetic fracture 
                    
                        in 5-30% of primary TEAs
                    
                        causes
                    
                        trauma
                    
                        osteoporosis
                    
                        aseptic loosening
                    
                        stress shielding
                    
                        poor technique
                    
                        non compliance with activity restriction
                    
                        classification based on that for periprosthetic femoral fractures (see table below)
                    
                        Mayo (O'Driscoll & Morrey) Classification of Periprosthetic fracture
                    
                        Characteristics
                    
                        Treatment
                    
                        Type I
                    
                        Periarticular fracture involving the humeral condyle or olecranon.
                    
                        Caused by osteolysis around hinge components and distracting forces from muscle attachments
                    
                        Undisplaced - Immobilization /soft tissue repair is sufficient to achieve fibrous union (Rigid fixation not required).
                    
                        Displaced - ORIF with heavy nonabsorbable sutures or tension band wiring (if limited periprosthetic bone)
                    
                        Type II
                    
                        Fracture along length of humeral or ulnar stem. Subtypes:
                    
                          II1: well-fixed implant
                    
                            II2: loose implants, good bone stock
                    
                            II3: loose implants, severe bone loss
                    
                        I1: ORIF with component retention +/- strut allograft
                    
                        II2: Revision arthroplasty using long-stem prosthesis ± strut allograft and impaction bone grafting. Locking plates/ cerclage wires may be added for added stability.
                    
                        II3: Require revision arthroplasty with extensive allograft supplementation. Often times require resection arthroplasty
                    
                        Type III
                    
                        Distal to prosthesis.
                    
                        Treated like routine fractures.
                    
                         Radiographs/CTs to ensure implants are not loose, cement mantle not cracked.
                    
                        If implants are well-fixed, immobilization for humerus and ORIF for ulna.
                    
                        If implants are loose, treat as Type II2 fractures.

Action	Numeric Key	Letter Key	Function Key
Show Bullets		S	Enter (frontside only)
20%	1	N
40%	2	H
60%	3	F	Enter (backside only)
80%	4	E
100%	5	M
Toss	0	T

Mayo (O'Driscoll & Morrey) Classification of Periprosthetic fracture
	Characteristics	Treatment
Type I	Periarticular fracture involving the humeral condyle or olecranon. Caused by osteolysis around hinge components and distracting forces from muscle attachments	Undisplaced - Immobilization /soft tissue repair is sufficient to achieve fibrous union (Rigid fixation not required). Displaced - ORIF with heavy nonabsorbable sutures or tension band wiring (if limited periprosthetic bone)
Type II	Fracture along length of humeral or ulnar stem. Subtypes: II1: well-fixed implant II2: loose implants, good bone stock II3: loose implants, severe bone loss	I1: ORIF with component retention +/- strut allograft II2: Revision arthroplasty using long-stem prosthesis ± strut allograft and impaction bone grafting. Locking plates/ cerclage wires may be added for added stability. II3: Require revision arthroplasty with extensive allograft supplementation. Often times require resection arthroplasty
Type III	Distal to prosthesis. Treated like routine fractures. Radiographs/CTs to ensure implants are not loose, cement mantle not cracked.	If implants are well-fixed, immobilization for humerus and ORIF for ulna. If implants are loose, treat as Type II2 fractures.