Total Scapular Resection & Endoprosthetic Reconstruction: An Intraoperative Masterclass

Introduction and Epidemiology

Tumors arising from the scapula represent a unique oncologic and reconstructive challenge due to the complex three-dimensional anatomy and dynamic biomechanics of the shoulder girdle. Because the scapula is enveloped by a robust muscular sleeve, primary bone tumors and secondary soft tissue sarcomas often reach considerable volume before clinical detection. Patients typically present with deep-seated pain, a palpable mass, or restricted shoulder mechanics. In the adult population, chondrosarcoma remains the most prevalent primary osseous malignancy of the scapula, whereas Ewing sarcoma predominates in pediatric cohorts. Furthermore, aggressive periscapular soft tissue sarcomas frequently invade the osseous architecture of the scapula secondarily.

Historically, prior to the 1970s, the standard of care for high-grade sarcomas of the shoulder girdle was the forequarter amputation, a profoundly morbid procedure resulting in severe functional and psychological deficits. The paradigm shifted dramatically in 1977 when Marcove et al. popularized the Tikhoff-Linberg resection. This limb-sparing technique demonstrated local oncologic control and overall survival rates comparable to radical amputation, while critically preserving functional capacity in the ipsilateral elbow, wrist, and hand.

Today, limb-sparing surgery with complex endoprosthetic or biologic reconstruction is the gold standard for the vast majority of scapular malignancies. Forequarter amputation is now strictly reserved for massive, fungating, or infected tumors, cases of catastrophic local recurrence, or when the neoplasm irresectably encases the neurovascular bundle or invades the deep thoracic cavity.

Surgical Anatomy and Biomechanics

A profound mastery of the regional anatomy is the cornerstone of safe oncologic resection and functional reconstruction in the shoulder girdle. The local anatomy dictates the margins of resection, the feasibility of limb salvage, and the availability of motor units for dynamic reconstruction.

The Neurovascular Bundle and Axillary Anatomy

The subclavian artery and vein transition into the axillary vessels as they cross the lateral border of the first rib, joining the cords of the brachial plexus beneath the clavicle. Distal to this point, these structures are enveloped within a contiguous fibrous sheath, functioning clinically as a singular neurovascular bundle.

The axillary artery follows a predictable course medial and inferior to the coracoid process, transitioning into the brachial artery at the inferior border of the teres major. During its course, it yields several critical branches that must be systematically identified, ligated, and transected to achieve safe mobilization of the scapula:
1. Supreme Thoracic Artery: Arises proximal to the pectoralis minor.
2. Thoracoacromial Trunk & Lateral Thoracic Artery: Arise posterior to the pectoralis minor.
3. Subscapular Artery: The most critical branch for scapular mobilization. It bifurcates into the thoracodorsal artery and the circumflex scapular artery, which wraps around the lateral border of the scapula, intimately tethering the axillary vessels to the bone.
4. Anterior and Posterior Circumflex Humeral Arteries: Arise at the inferior border of the subscapularis, wrapping the surgical neck of the humerus.

Early ligation of the circumflex humeral and subscapular vessels is a mandatory surgical maneuver. This releases the tethering effect, permitting the axillary vessels and brachial plexus to be mobilized anteriorly and safely retracted away from the tumor mass.

Critical Neural Structures

Tumor expansion frequently distorts the normal neural topography, necessitating meticulous dissection.

• Suprascapular Nerve: Arising from the superior trunk, it traverses the suprascapular notch beneath the transverse scapular ligament. It is routinely sacrificed during total scapulectomy.
• Musculocutaneous Nerve: Arising from the lateral cord, it penetrates the coracobrachialis 2 to 7 cm distal to the coracoid. Tumors often displace this nerve anteriorly, leaving it vulnerable just beneath the superficial fascia. It must be isolated prior to releasing the conjoint tendon.
• Axillary Nerve: Coursing with the posterior circumflex humeral vessels through the quadrangular space, it is often stretched by scapular neoplasms but typically shielded by the subscapularis muscle. Preservation is critical if the deltoid is to be retained for reconstruction.
• Radial Nerve: Arising from the posterior cord, it courses anterior to the latissimus dorsi and teres major insertions before entering the spiral groove.
• Subscapular and Thoracodorsal Nerves: The upper and lower subscapular nerves are routinely ligated during scapulectomy. The thoracodorsal nerve, running directly anterior to the subscapularis, can often be spared to maintain latissimus dorsi innervation, which is vital for subsequent soft tissue coverage.

Indications and Contraindications

Patient Selection for Limb-Sparing Surgery

Limb-salvage surgery is indicated for the majority of high-grade primary bone sarcomas (e.g., osteosarcoma, chondrosarcoma, Ewing sarcoma) and periscapular soft tissue sarcomas. It is also an excellent palliative or curative option for isolated, destructive metastatic lesions (e.g., renal cell carcinoma, myeloma, thyroid carcinoma) that are refractory to radiation or systemic therapy.

Criteria for Total Scapular Prosthetic Reconstruction

To successfully implant and stabilize a total scapular prosthesis, specific motor units must be preserved to provide both dynamic suspension and adequate soft tissue coverage. The indispensable muscles include the trapezius, deltoid, rhomboids, serratus anterior, and latissimus dorsi. If oncologic margins require the sacrifice of these muscles, prosthetic reconstruction is contraindicated. In such cases, a biologic reconstruction utilizing static suspension (e.g., securing the remaining humerus to the clavicle via heavy Dacron tape) combined with dynamic muscle transfers (pectoralis major rotational flaps) is utilized.

Absolute and Relative Contraindications

Absolute Contraindications:
* Tumor encasement or direct invasion of the major axillary vessels or the cords of the brachial plexus. (Note: Simple abutment or involvement of a single nerve branch is not an absolute contraindication).
* Massive, full-thickness invasion of the thoracic cavity/chest wall precluding negative margins.

Relative Contraindications:
* Extensive soft tissue contamination from a poorly planned prior biopsy.
* Active, uncontrolled local infection.
* Recurrent high-grade sarcomas where negative margins are unachievable without forequarter amputation.
* Displaced pathologic fractures with massive hematoma contamination that fail to consolidate following neoadjuvant chemotherapy.

Preoperative Planning, Imaging, and Biopsy

Advanced Imaging Modalities

Thorough preoperative staging is non-negotiable. While plain radiography provides baseline data regarding osseous destruction and matrix mineralization, advanced cross-sectional imaging dictates the surgical plan.

• Computed Tomography (CT): Essential for evaluating subtle cortical erosion of the underlying rib cage and detecting faint intralesional mineralization. Contrast-enhanced CT provides excellent visualization of the tumor's relationship to the chest wall.
• Magnetic Resonance Imaging (MRI): The gold standard for defining intraosseous marrow extent (determining the exact level of the humeral osteotomy), extraosseous soft tissue extension, and the presence of skip metastases. T1-weighted imaging is critical for assessing the fat planes between the tumor and the neurovascular bundle.
• Angiography and Venography: Indicated when vascular displacement is suspected. Venous occlusion on venography highly correlates with direct brachial plexus infiltration.

Oncologic Biopsy Principles

The biopsy must be meticulously planned and executed, as an improperly placed tract can contaminate salvageable muscle compartments, converting a limb-sparing candidate into an amputation.

Core needle biopsies under CT or fluoroscopic guidance are preferred. A single puncture site should be used, with the needle redirected to sample multiple geographic regions of the tumor. The biopsy tract must be placed directly within the planned surgical incision so it can be excised en bloc with the specimen. For tumors of the scapular body, a direct posterior approach is mandatory; anterior approaches carry a high risk of contaminating the neurovascular bundle and axilla.

Preoperative Planning and Patient Positioning

Final determination of resectability is made intraoperatively. The patient is positioned in a full lateral or "floppy" semi-lateral decubitus position, utilizing a beanbag for stabilization. This allows unhindered access from the anterior chest wall to the posterior spinous processes. The entire forequarter, including the neck, chest, and full upper extremity, is prepped and draped free to allow manipulation of the limb during the resection.

Detailed Surgical Approach and Technique

The Utilitarian Incision and Exposure

Most total scapular resections demand a combined anterior and posterior approach. The anterior limb utilizes an extended deltopectoral incision to expose the axillary vessels and brachial plexus. The posterior limb follows the spine of the scapula and curves distally along the vertebral border.

While a posterior-only approach is theoretically possible for small, posteriorly confined intraosseous lesions, any tumor with an anterior soft tissue component requires the combined approach to safely dissect the neurovascular structures away from the tumor capsule.

Type IV Resection: Extra-articular Total Scapula and Humeral Head (Tikhoff-Linberg)

The Type IV resection is an extra-articular en bloc resection of the entire scapula, the glenohumeral joint, the proximal humerus, and often the distal clavicle. It is the workhorse procedure for high-grade bone sarcomas involving the glenoid or proximal humerus with intra-articular extension.

1. Posterior Dissection: A large posterior fasciocutaneous flap is elevated. The trapezius and rhomboids are released from the scapular spine and vertebral border. The latissimus dorsi is widely mobilized but preserved. If oncologically safe, the deltoid is preserved and reflected.
2. Anterior Dissection: The pectoralis major is released from its humeral insertion. The conjoint tendon (short head of biceps, coracobrachialis) and pectoralis minor are released from the coracoid, carefully protecting the underlying musculocutaneous nerve.
3. Vascular Control: The subscapular and circumflex humeral vessels are isolated, ligated, and divided, allowing the neurovascular bundle to be swept anteriorly and medially off the tumor.
4. Osteotomy: The proximal humerus is transected 2 to 3 cm distal to the MRI-defined marrow extent. The specimen is delivered en bloc.

Prosthetic Reconstruction for Type IV Resections

If adequate musculature remains, a constrained total scapular endoprosthesis is implanted.

A critical step is the reconstruction of the joint capsule using a Gore-Tex tube graft to prevent postoperative dislocation. The Gore-Tex sleeve is secured to the proximal humeral prosthesis and the prosthetic glenoid neck using heavy 3-mm Dacron tape.

Muscle reconstruction is paramount. The modern scapular prosthesis is highly fenestrated to allow for robust tenodesis.
* The prosthesis is seated in a biological pocket between the serratus anterior, rhomboids, and latissimus dorsi.
* The trapezius is tenodesed directly to the remaining deltoid over the superior aspect of the prosthesis.
* The latissimus dorsi is rotated superiorly and medially, sutured to the axillary border of the prosthesis, and tenodesed to the rhomboids to provide complete soft tissue coverage.

Type III Resection: Intra-articular Total Scapulectomy

The Type III resection is primarily indicated for massive periscapular soft tissue sarcomas that invade the scapula but spare the glenohumeral joint capsule and proximal humerus.

1. Exposure: Similar utilitarian incisions are utilized. The rhomboids, trapezius, and deltoid are released. The scapula is elevated off the chest wall from medial to lateral.
2. Joint Disarticulation: The rotator cuff tendons (supraspinatus, infraspinatus, subscapularis) are transected. The anterior capsule is opened, and the long head of the biceps is tagged and divided. The acromioclavicular joint is disarticulated.
3. Delivery: The scapula is rotated, allowing direct visualization of the axillary contents from a posterior perspective, facilitating safe delivery of the bone.

Reconstruction for Type III Resections

If a prosthesis is not utilized, a dual suspension technique is employed. The proximal humerus is suspended from the remaining distal clavicle using 3-mm Dacron tape. The biceps, coracobrachialis, and triceps are advanced and secured through drill holes in the clavicle.

If a prosthesis is used, the humeral head is mated to the prosthetic glenoid. The trapezius is tenodesed to the deltoid, and the rhomboids are secured to the medial border of the prosthesis, subsequently covered by the latissimus dorsi.

Complications and Management

Extensive resections of the shoulder girdle carry inherent risks.
* Wound Complications: Skin flap necrosis is a known risk due to extensive subcutaneous undermining. Meticulous handling of the fasciocutaneous flaps and ensuring the prosthesis is entirely covered by well-vascularized muscle (latissimus dorsi) minimizes this risk.
* Instability: Glenohumeral dissociation or prosthetic dislocation occurs in less than 5% of modern reconstructions, largely mitigated by the routine use of Gore-Tex capsular reconstruction and strict postoperative immobilization.
* Neurologic Deficits: Transient traction neurapraxia of the brachial plexus is observed in a small percentage of cases due to intraoperative manipulation and the weight of the unsupported limb postoperatively. Permanent deficits requiring nerve sacrifice are exceedingly rare.

Postoperative Rehabilitation Protocols

Rigorous postoperative management is critical to the success of the reconstruction.

Immediate Postoperative Phase (0-2 Weeks):
* Pain control is managed via an indwelling epineural catheter infusing 0.25% bupivacaine for 3 to 5 days.
* The operative extremity is strictly immobilized in a custom orthosis maintaining 45 to 60 degrees of shoulder abduction and 45 degrees of elbow flexion to eliminate tension on the muscle transfers and capsular repair.
* Immediate active range of motion (ROM) of the wrist and hand is initiated.

Intermediate Phase (2-6 Weeks):
* Upon suture removal and wound consolidation, gentle pendulum exercises and passive ROM (flexion, extension, internal/external rotation) are initiated under the guidance of a specialized physical therapist.
* Elbow ROM is progressed.

Late Phase (12+ Weeks):
* Isometric and active-assisted strengthening begins.
* Light resistance training (Thera-Bands) is introduced.
* Permanent Restrictions: Patients are educated on a lifetime lifting restriction of 15 to 20 pounds for the operative extremity to prevent late prosthetic failure or catastrophic soft tissue rupture.

Outcomes and Functional Expectations

Endoprosthetic reconstruction of the scapula yields highly reliable functional outcomes. The primary goal—a painless, stable shoulder girdle with normal distal extremity function—is routinely achieved.

According to the Musculoskeletal Tumor Society (MSTS) scoring system, patients typically achieve scores ranging from 24 to 27 out of 30 (80% to 90%).

• Distal Function: Elbow, wrist, and grip strength return to normal. Patients can easily perform activities of daily living, including reaching their head, opposite shoulder, and perineum.
• Proximal Function: Active forward elevation and abduction generally plateau between 25 and 45 degrees (Grade 3 to 4 motor strength). Scapular protraction, retraction, and elevation are well preserved, allowing patients to stabilize the extremity during lifting.
• Limitations: The primary functional deficit lies in active overhead elevation and high-demand recreational activities. However, the preservation of a functional hand and elbow far outweighs the limitations of glenohumeral restriction.

Summary of Key Guidelines

1. Imaging is Paramount: Rely on MRI to determine intraosseous extent and CT/Angiography to assess neurovascular and chest wall involvement.
2. Biopsy Discipline: Always utilize a posterior approach for scapular body lesions; orient the tract longitudinally within the planned resection ellipse.
3. Anterior Control: For tumors with anterior extension, utilize a deltopectoral approach first to identify and protect the brachial plexus and ligate the circumflex/subscapular vessels.
4. Muscle Preservation: The success of prosthetic reconstruction hinges on the viability of the trapezius, latissimus dorsi, and deltoid.
5. Capsular Reconstruction: Always utilize a Gore-Tex tube graft to reconstruct the joint capsule in Type IV resections to prevent inferior subluxation.