Mastering Linkable Total Elbow Arthroplasty for Primary Degenerative Arthritis

Alright, fellows, gather 'round. Welcome to the operating theater. Today, we're tackling a case of primary degenerative arthritis of the elbow, specifically performing a linkable total elbow arthroplasty. This is an uncommon but challenging condition, often affecting younger, active patients, which makes our implant choice and technique absolutely critical.

Understanding Primary Degenerative Arthritis of the Elbow

Before we even consider making an incision, let's quickly review the pathology. Primary degenerative arthritis of the elbow is distinct from typical age-related changes. It's characterized by progressive loss and fragmentation of joint cartilage, leading to distortion, cyst formation, and significant bone sclerosis in both the radiohumeral and ulnohumeral joints.

This condition is rare, affecting less than 2% of the population, predominantly middle-aged men, often in their dominant extremity. We see extensive osteophyte formation, particularly around the olecranon, coronoid process, and within the fossae. The radiocapitellar joint is often the earliest and most severely affected due to high axial, shearing, and rotational stresses, leading to a characteristic oblique "shaving" of the capitellum and hypertrophic callus on the radial neck. The ulnohumeral joint typically becomes more involved in advanced stages, though the central aspect is often spared initially.

Clinical Presentation: Patients often present with progressive loss of motion, particularly at the extremes of flexion and extension, where osteophytes impinge. Mechanical symptoms like locking and catching from loose bodies are common in about 10% of patients. Importantly, we must always evaluate for ulnar nerve symptoms, as up to 20% of these patients develop ulnar neuropathy due to direct compression or ischemia from expanding synovitis and osteophytes in the posteromedial aspect of the ulnohumeral joint. Medial joint pain can be the first sign of this neuropathy.

Imaging and Diagnostic Studies

Our preoperative workup is crucial. Standard anteroposterior (AP) and lateral radiographs will reveal characteristic features: joint space narrowing, subchondral sclerosis, and prominent osteophytes in the coronoid, capitellar, and olecranon fossae.

FIG 2 A,B: Anteroposterior and lateral views of a right osteoarthritic elbow show narrowing of the joint line and subchondral sclerosis, with formation of osteophytes in the coronoid, capitellar, and olecranon fossae.

However, radiographs often don't fully delineate all osteophytes. For surgical planning, especially when considering open débridement or arthroplasty, a Computed Tomography (CT) scan is indispensable. It provides detailed structural anatomy, accurately localizing osteophytes and loose bodies, and helps us visualize the extent of articular surface involvement. Three-dimensional reconstructions from CT data are particularly valuable for planning osteophyte removal.

FIG 2 C: Computed tomography of the elbow demonstrating marginal osteophytes on the ulna and olecranon fossa.

MRI, while useful for soft tissue, rarely provides additional useful information for primary osteoarthritis of the elbow and is generally not indicated.

Preoperative Planning: The Blueprint for Success

Our patient today is a 68-year-old gentleman, a retired carpenter, with severe pain and limited range of motion in his dominant right elbow, refractory to nonoperative management. He has low physical demands, making him an ideal candidate for total elbow arthroplasty.

Implant Choice: Linkable Design

For primary degenerative arthritis, especially in this patient demographic, we favor linked (semiconstrained) or linkable implant designs. While unlinked (resurfacing) implants have theoretical advantages in preserving collateral ligaments and offloading stress, their major complication is instability. Our patient's age and activity level, combined with the extent of his disease, necessitate the stability offered by a linked design.

We've chosen a linkable system. This allows us to initially implant the components in an unlinked fashion, assessing stability. If adequate stability cannot be achieved intraoperatively, or if instability develops postoperatively, we can convert it to a linked implant by capturing the ulnohumeral articulation with an ulnar cap. This provides excellent versatility.

FIG 3 A: A linked implant with a semiconstrained, loose-hinged articulation, allowing some varus-valgus and rotational laxity.

FIG 3 B, C: Linkable implants can be used unlinked (B), or the ulnohumeral articulation can be captured, converting the unlinked implant to a linked implant (C).

Patient Positioning and Setup

Let's get our patient positioned correctly.

1. Supine Position: The patient is supine on the operating room table.
2. Scapular Bump: Place a small bump or blanket roll under the ipsilateral scapula. This helps to protract the scapula slightly, bringing the shoulder forward and allowing better posterior access to the elbow.
3. Arm Across Chest: The affected arm is then adducted and internally rotated, positioned across the chest.
4. Bolster Support: Support the entire arm on a padded bolster. This provides stability and maintains the elbow in a flexed position, which will be crucial for exposure. Ensure the bolster is firm but allows for easy manipulation of the arm during the procedure.

FIG 4: Patient positioning with the arm across the chest supported on a bolster.

1. Tourniquet Application: A sterile tourniquet is applied to the upper arm. The use of a sterile tourniquet is key here, fellows. It significantly increases our sterile field, allowing for more proximal exposure if needed without breaking sterility. We'll inflate it once we're draped and ready for incision.
2. Fluoroscopy: Ensure the C-arm is positioned for easy access to obtain both AP and lateral views of the elbow without repositioning the patient. We'll use fluoroscopy for templating and verifying component alignment.

Intraoperative Execution: The Surgical Masterclass

Alright, scrub in, fellows. Let's begin.

1. Surgical Exposure: Posterior Approach

We're using a straight posterior, midline incision. This approach offers excellent visualization of the distal humerus and proximal ulna, which is essential for total elbow arthroplasty.

• Incision: Identify the medial tip of the olecranon. Our incision will run just off its medial aspect, extending proximally along the posterior humerus and distally along the posterior ulna. Make a precise, straight incision through the skin.

  
  
  

TECH FIG 1: Straight posterior midline skin incision is placed off the medial aspect of the olecranon.

• Flap Elevation: Now, carefully elevate full-thickness skin flaps medially and laterally. The extent of this elevation will depend on our chosen triceps management strategy. For this case, we'll elevate sufficiently to expose the entire posterior aspect of the distal humerus, olecranon, and the triceps mechanism.

  Surgical Warning: Be meticulous with your flap elevation. Avoid buttonholing the skin or creating excessively thin flaps, which can compromise wound healing. Maintain a consistent plane just above the deep fascia.

2. Ulnar Nerve Identification and Protection

This is a crucial step, fellows. The ulnar nerve is highly vulnerable in this approach, especially with the osteophyte burden we expect in degenerative arthritis.

• Identification: Carefully identify the ulnar nerve in the cubital tunnel. It lies posterior to the medial epicondyle and runs between the two heads of the flexor carpi ulnaris. Gently palpate it and use blunt dissection to free it.
• Neurolysis (if needed): In cases with significant neuropathy or impingement, a formal neurolysis of the ulnar nerve may be necessary.
• Transposition: Once identified and freed, gently mobilize the nerve and transpose it anteriorly, out of harm's way.

• Protection: Secure the nerve with a Penrose drain or a vessel loop, ensuring it is protected throughout the entire procedure. Keep it well-padded and moist.

  Surgical Warning: The ulnar nerve is the most commonly injured nerve during elbow surgery. Always identify, protect, and if necessary, transpose it. A missed or poorly protected nerve can lead to devastating postoperative complications.

3. Triceps Management: Triceps-Splitting Approach

For total elbow arthroplasty, we need excellent exposure. While triceps-sparing approaches reduce postoperative weakness, they often compromise visualization. Triceps-reflecting approaches provide good exposure but require careful reattachment. Today, we'll use a triceps-splitting approach, which offers excellent visualization while maintaining some continuity of the triceps.

• Midline Split: Identify the midline of the triceps tendon. Using a scalpel, make a precise, longitudinal incision directly through the center of the triceps tendon, extending proximally into the muscle belly and distally towards the olecranon.

• Subperiosteal Elevation: Continue the split distally to the subcutaneous border of the ulna. Now, subperiosteally elevate the medial and lateral portions of the triceps mechanism from the olecranon.

  • Medial Triceps: Elevate the medial triceps in continuity with the flexor carpi ulnaris. Be aware that the attachment of the medial triceps to the ulna is often more tenuous than the lateral side.
  • Lateral Triceps: Elevate the lateral triceps in continuity with the anconeus. This flap is typically more robust.

  
  
  

TECH FIG 2 A: Triceps-splitting approach carried from the subcutaneous border of the ulna proximally into the triceps tendon. The medial and lateral triceps are subperiosteally elevated from the olecranon.

4. Joint Exposure and Ligament Release

With the triceps split and reflected, we now have direct access to the posterior aspect of the joint.

• Collateral Ligament Release: The medial collateral ligament (MCL), specifically its anterior bundle, and the lateral collateral ligament (LCL) complex must be released from their humeral attachments. Tag these ligaments with non-absorbable sutures for later repair. This release is critical to allow for joint distraction and proper component placement.

  
  
  

TECH FIG 2 B: The medial and lateral collateral ligaments are released from their humeral attachment.

• Joint Dislocation/Separation: With the ligaments released, externally rotate the shoulder and flex the elbow. This maneuver will allow the ulna to separate from the humerus, dislocating the joint and providing full exposure of the articular surfaces.

  
  
  

TECH FIG 2 C: The shoulder is externally rotated and the elbow is flexed, allowing the ulna to separate from the humerus.

5. Osteophyte Removal and Debridement

Now that the joint is wide open, we can address the pathology.

• Systematic Debridement: Start by removing all loose bodies. These are often found in the coronoid and olecranon fossae. Use rongeurs and curettes.

• Osteophyte Excision: Meticulously excise all osteophytes from the olecranon, coronoid process, and the fossae. Pay particular attention to the posterior olecranon osteophytes and those impinging in the coronoid fossa. This step is critical for restoring range of motion and preventing impingement postoperatively.

  
  
  

(Image depicting removal of osteophytes from the olecranon fossa.)

> **Surgical Pearl:** Use a small osteotome or a high-speed burr for precise osteophyte removal, especially in tight areas. Protect the underlying bone and soft tissues. Ensure complete removal to maximize the functional arc of motion.

6. Humeral Component Preparation

We'll now prepare the distal humerus for the humeral component.

• Distal Humeral Cut: Use an oscillating saw with a specialized cutting guide to resect the distal humerus. The goal is to create a flat, perpendicular cut that allows for optimal implant seating and restoration of the valgus angle.

• Intramedullary Reaming: Insert the appropriate-sized intramedullary reamer into the humeral canal. Ream sequentially until cortical chatter is felt, ensuring good diaphyseal fit. This prepares the canal for the humeral stem.

  
  
  

(Image depicting intramedullary reaming of the humerus for the humeral component.)

• Condylar Preparation: Use specific cutting blocks and burrs to prepare the condylar surfaces of the distal humerus to accept the humeral component's condylar geometry. This involves creating the appropriate slots and surfaces for the implant.

7. Ulnar Component Preparation

Next, we prepare the proximal ulna.

• Olecranon Cut: Use an oscillating saw with an ulnar cutting guide to resect the olecranon. The goal is to create a flat, perpendicular cut across the olecranon, ensuring the correct level for the ulnar component.

• Intramedullary Reaming: Insert the appropriate-sized intramedullary reamer into the ulnar canal. Ream sequentially to prepare the canal for the ulnar stem. Ensure the reamer is centered in the canal.

  
  
  

(Image depicting intramedullary reaming of the ulna for the ulnar component.)

> **Surgical Pitfall:** Over-reaming or eccentric reaming can lead to poor implant fixation and potential fracture. Always ream incrementally and check alignment.

8. Trial Reduction

This is a critical step to assess fit, stability, and range of motion before cementing the definitive implants.

• Trial Implants: Insert the trial humeral and ulnar components.
• Reduction: Carefully reduce the elbow joint, bringing the trial components together.
• Assess Stability: Flex and extend the elbow through its full arc of motion. Assess varus-valgus stability and rotational stability.
• Range of Motion: Check the full flexion-extension arc. We're aiming for a functional arc, typically 30-130 degrees, without impingement.

• Soft Tissue Balance: Ensure the soft tissues are balanced. If the joint feels too tight in extension, further soft tissue release (e.g., anterior capsule) may be needed. If it's too loose, especially in varus-valgus, this is where the linkable design becomes crucial.

  
  
  

(Image depicting trial reduction of the elbow components.)

> **Surgical Decision Point:** If, after trial reduction, the elbow remains unstable in the unlinked configuration, this is the time to decide to convert to a linked construct. The linkable system allows us to immediately place the ulnar cap to create a linked articulation. This patient's stability feels good, so we will proceed with the unlinked configuration, but we have the option to link if needed later.

9. Definitive Implant Implantation

Now, we move to the final components.

• Cementing Technique: We will use bone cement for fixation. Prepare the cement according to the manufacturer's instructions.

  • Ulnar Component: Apply cement to the ulnar intramedullary canal using a cement gun, ensuring good pressurization. Also, apply a thin mantle of cement to the posterior aspect of the ulnar component. Insert the definitive ulnar component, ensuring correct alignment and rotation.

    
    
    

(Image depicting cement application for the ulnar component.)

*   **Humeral Component:** Similarly, apply cement to the humeral intramedullary canal and to the posterior aspect of the humeral component. Insert the definitive humeral component, ensuring proper alignment and rotation.

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(Image depicting final humeral component insertion.)

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(Image depicting final ulnar component insertion.)

• Reduction and Cement Curing: Carefully reduce the joint once both components are in place. Hold the elbow in a stable position (e.g., 90 degrees flexion) until the cement has fully cured. Remove any excess cement from the joint margins.

  
  
  

(Image depicting the unlinked components in place after final implantation.)

> **Surgical Warning:** Ensure no cement extrudes into the joint space or impinges on the ulnar nerve. Cement debris can cause significant pain and reduced motion.

10. Intraoperative Assessment and Closure

• Final Range of Motion and Stability: After cement curing, perform a final assessment of the range of motion, stability, and tracking of the joint. Confirm the unlinked components are stable. If not, this is the last chance to link them.
• Ligament Repair: Reattach the tagged medial and lateral collateral ligaments to their humeral origins using strong, non-absorbable sutures. This helps restore inherent stability and contributes to implant longevity.

• Triceps Repair: Repair the triceps mechanism. Close the longitudinal split in the triceps tendon using strong, interrupted sutures. Reattach the subperiosteally elevated medial and lateral triceps flaps to the olecranon. This is critical for extensor strength and preventing extensor lag.

  
  
  

(Image depicting the repair of the triceps mechanism.)

• Ulnar Nerve Repositioning: Ensure the ulnar nerve is free, well-padded, and lies in a tension-free anterior position.
• Wound Closure: Irrigate the wound thoroughly. Place a drain if significant bleeding is anticipated. Close the deep fascia, subcutaneous tissue, and skin layers meticulously.

Postoperative Rehabilitation and Complication Management

Our work doesn't end when the patient leaves the OR. Postoperative management is just as critical for a successful outcome.

Immediate Postoperative Care

• Immobilization: The elbow will be placed in a posterior splint or hinged brace, typically at 90 degrees of flexion, for initial protection.
• Pain Management: Aggressive multimodal pain management is crucial.
• DVT Prophylaxis: Standard DVT prophylaxis protocols will be initiated.

Rehabilitation Protocol

• Early Motion (within 1-3 days): For a stable, unlinked TEA, we typically initiate early, gentle active and passive range of motion (ROM) exercises. The hinged brace will be set to allow a controlled arc of motion (e.g., 30-90 degrees initially), gradually increasing as tolerated.
  • Weight-Bearing: Strict non-weight-bearing for the first 6-8 weeks. Light activities of daily living are permitted, but no lifting, pushing, or pulling.
  • Strengthening: Gentle isometric strengthening of the triceps and biceps can begin around 4-6 weeks, progressing to light resistance exercises after 8-12 weeks, depending on stability and healing.
  • Return to Activity: Return to full, unrestricted activity will be gradual, typically 6-12 months, with permanent restrictions on heavy lifting (generally no more than 5-10 lbs) and repetitive impact activities to protect the implant.

Potential Complications and Management

• Infection: A devastating complication. Managed with surgical débridement, IV antibiotics, and potentially two-stage revision arthroplasty.
• Ulnar Neuropathy: Despite careful transposition, postoperative ulnar nerve irritation can occur. Most resolve with conservative management (padding, rest). Persistent symptoms may require re-exploration and further neurolysis.
• Instability: This is a primary concern with unlinked implants. If instability develops (subluxation or dislocation), we would convert the unlinked system to a linked system by placing the ulnar cap. This is the distinct advantage of our chosen linkable implant.
• Aseptic Loosening: Over time, mechanical stresses can lead to loosening of the components. This often presents with pain and radiographic changes. Revision arthroplasty may be required.
• Triceps Insufficiency/Rupture: Can lead to extensor lag. Managed with activity modification, physical therapy, or surgical repair in severe cases.
• Periprosthetic Fracture: Can occur intraoperatively or postoperatively. Managed based on fracture pattern, stability, and implant involvement, often requiring revision or internal fixation.
• Heterotopic Ossification: Can limit ROM. Prophylaxis with NSAIDs or radiation may be considered, especially in high-risk patients.

This procedure, while complex, offers significant pain relief and functional improvement for carefully selected patients with primary degenerative arthritis of the elbow. The key, fellows, is meticulous planning, precise execution, and a thorough understanding of both the anatomy and the implant system. Any questions?

Additional Intraoperative Imaging & Surgical Steps

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