Evaluation and Classification of Proximal Humeral Fractures

Sophia Cariati Medical WriterHost Orthopaedic Surgeon: Evan L. Flatow, MD Chief of Shoulder Surgery Department of Orthopaedics Mt. Sinai Medical Center New York, NYGuest Speaker: Frances Cuomo, MD Assistant Professor of Clinical Orthopaedic Surgery New York University School of Medicine New York, NYHost Orthopaedic Fellow: Yassamin Hazrati, MD Fellow, Shoulder Surgery Mt. Sinai Medical Center New York, NY

Medscape Orthopedics. 2001;5(3) 

Evaluation and Classification of Proximal Humeral Fractures

At most major medical centers, Orthopaedic Grand Rounds are lectures given by orthopaedic surgeons of national and international prominence, providing opportunities for faculty, residents, and fellows to present difficult clinical case studies and original basic science research, and to engage in discussions on timely and controversial topics.

Medscape Orthopaedics is pleased to make these valuable educational programs available online to an ever-increasing segment of the orthopaedic community. Visitors to the Medscape Grand Rounds programs are encouraged to provide commentary on the topics presented.

Proximal humeral fractures are not rare, accounting for 4% to 5% of all fractures in the United States.[1] Most of these fractures are minimally displaced or nondisplaced and can be managed conservatively with immobilization and early motion. However, 15% to 20% are displaced and represent a challenge to the orthopaedic surgeon. Debate continues to surround the reliability of available classification systems, indications for surgery, and the most effective fixation techniques. Nevertheless, successful management of these fractures depends upon a detailed patient history, thorough clinical exam, careful and accurate x-rays, and CT and MRI scans as needed.

Issues in the management of proximal humeral fractures were reviewed at an orthopaedic Grand Rounds presentation at Mt. Sinai Hospital in New York, NY, on October 11, 2000, hosted and led by Evan Flatow, MD, with a presentation by Fran Cuomo, MD.

Clinicians should maintain a high index of suspicion for arterial injuries, especially among the elderly population. The blood supply to the humeral head is via the ascending humeral circumflex artery as well as the anterior and posterior circumflex arteries. Axillary artery occlusion should be suspected if the arm is large, swollen, and weeping. If a vascular injury is suspected, an angiogram is indicated.

In addition, to determine whether the brachial plexus or axial nerve is involved, a neurologic evaluation is recommended.

Careful radiographic evaluation of patients with proximal humeral fractures is critical to accurate diagnosis and successful treatment. Anteroposterior (AP) and axillary views are mandatory. Dubbed the "trauma series" by Neer in 1970, this series of x-rays is the most important diagnostic tool for evaluating proximal humeral fractures.

The traditional axillary view provides an excellent image. It does, however, require arm abduction, which can be painful and may alter the fracture position.

Axillary view with a Velpeau bandage may be used for patients who cannot comply with the positioning required for an axillary view.[2] The resulting image is somewhat distorted yet accurate. Since the arm is in the sling for this view, the procedure is less painful and does not change the fracture position.

Computed tomography (CT) scanning and magnetic resonance imaging (MRI) are sometimes indicated. These imaging techniques can help quantify the extent of tuberosity displacement, the size of humeral head indentation fractures, and the amount of articular involvement in head-splitting fractures.

Although some studies contest the accuracy of the Neer and AO classification systems,[3,4] the Neer system is still generally used to guide treatment and estimate the prognosis of patients with proximal humeral fractures.

According to Codman's observation,[5] fractures of the proximal humerus produce a combination of the 4 following segments:

  • articular surface

  • humeral shaft

  • greater tuberosity

  • lesser tuberosity

In addition, Codman proposed that fracture lines follow the epiphyseal plate.

The AO classification system for proximal humeral fractures is not commonly used. It is divided into 3 categories based on the severity of injury and likelihood of avascular necrosis of the humeral head.[6]

  • Type A Fractures
    No vascular isolation of articular segment

  • Type B Fractures
    Partial vascular isolation of articular segment

  • Type C Fractures
    Total vascular isolation of articular segment

Each group is then subdivided numerically, with higher numbers indicating greater severity.

The Neer classification system includes 4 segments -- I, II, III, and IV -- and also rates displacement and vascular isolation.[7,8] The 4 segments are as follows:

  • greater tuberosity

  • lesser tuberosity

  • humeral head

  • shaft

According to Neer, a fracture is displaced when there is more than 1 cm of displacement and 45° of angulation of any one fragment with respect to the others.

Muscle pulls cause displacement. The supraspinatus and infraspinatus pull the greater tuberosity superiorly and the subscapularis pulls the lesser tuberosity medially, while the pectoralis major adducts the shaft medially.

Two-part fractures involve any of the 4 parts and include 1 fragment that is displaced. Three-part fractures include a displaced fracture of the surgical neck in addition to either a displaced greater tuberosity or lesser tuberosity fracture. Four-part fractures include displaced fractures of the surgical neck and both tuberosities.

The modified Neer classification system is a simplified version in which Roman numerals are not used.

An orthopaedic surgeon can also use a still further simplified version of the Neer classification system, in which the direction of dislocation is less important and isolated anatomic neck fractures are not included.

Although the reliability of these classification systems has been questioned, reproducibility and accuracy is increased by carefully positioned x-rays and with the level of experience and expertise of the surgeon. Furthermore, intraoperative findings, especially with respect to the lesser tuberosity, can greatly help in the assessment of these fractures. In addition, early postoperative x-rays are essential to the successful management of these fractures.

The majority of proximal humeral fractures -- minimally displaced or nondisplaced -- can be successfully managed conservatively.[9,10] Treatment includes immobilization with a sling and early range of motion exercises as soon as the patient can do so with minimal pain. Pendulum exercises and isometric strengthening of the biceps and triceps should begin after 1 week of immobilization. At 3-4 weeks, the patient can begin passive flexion and passive external rotation exercises. Overhead-pulley exercises can be started at 4-5 weeks.

A 68-year-old man tripped and fell in a restaurant. He was seen in the emergency room where the following x-rays were taken.

The AP lateral and axillary x-rays show a nondisplaced greater tuberosity fracture. This fracture was treated nonoperatively. The nondisplaced fracture is amenable to nonoperative treatment with close follow-up

Two-part fractures can include greater tuberosity displaced fractures, surgical neck displaced fractures, or lesser tuberosity displaced fractures.

In 2-part surgical neck fractures, the shaft is usually displaced medially and anteriorly while the tuberosities are attached to the head. There is usually anterior angulation of the fragment, and the fracture can look "varus" or "valgus" depending upon the rotation.

Treatment options include closed reduction and percutaneous pinning, open reduction and stabilization with a blade-plate, and open reduction and stabilization with intramedullary Ender's rods plus interfragmentary sutures if surgical neck comminution is present. Closed reduction with percutaneous pinning is indicated in patients with good bone quality and minimally comminuted or noncomminuted fractures. Open reduction and internal fixation (ORIF) is indicated in patients with severely comminuted fractures or poor bone quality. Intramedullary Ender's rods plus interfragmentary sutures are used in patients with advanced osteoporosis.

Some fractures can be easily classified as 2-part greater tuberosity fractures according to the x-rays.

In other cases, it is hard to see the greater tuberosity on the x-rays; sometimes it looks like calcium and other times it appears to be superimposed on the humeral head.

As a result, lateral and axillary views are often helpful at visualizing the greater tuberosity.

In some cases, MRI is useful in visualizing nondisplaced greater tuberosity fractures.

Greater tuberosity fractures result in rotator cuff avulsion as well as loss of dynamic stability.

Dislocated 2-part greater tuberosity fractures may reduce with glenohumeral reduction.

ORIF is often the treatment of choice for 2-part greater tuberosity fractures. Heavy, nonabsorbable interfragmentary sutures are used for fixation, incorporating the rotator cuff combined with repair of any rotator cuff injuries that are present.

A 54-year-old woman fell and landed on her dominant arm. The following 2 x-rays were acquired in the emergency room.

The fracture dislocation was reduced in the emergency room. These x-rays were taken after reduction.

During a follow-up visit 11 days later, these x-rays were taken and show evidence that the greater tuberosity was displaced.

This patient was taken to the operating room for open reduction of the fragment as well as repair of the rotator cuff. This postoperative x-ray demonstrates the status following ORIF with tension band sutures.

Two-part displaced lesser tuberosity fractures are quite rare and are easily missed on x-rays. A glenohumeral reduction can sometimes reduce them to 1-part fractures.

A 52-year-old, right-handed man fell on the ice. X-rays were taken in the emergency room, after which the patient was told that he was fine. He returned to the office 1 week later, complaining of persistent pain and difficulty using his right arm. Upon examination, he had decreased external rotation and a positive lift-off test. These x-rays of his right shoulder were taken in the office 1 week after the injury, and showed evidence of a displaced lesser tuberosity fracture.

The patient underwent open reduction with cerclage wire and plate fixation in order to treat the lesser tuberosity fracture. This x-ray was obtained postoperatively.

Overall, the successful management of 3-part fractures includes ORIF or, rarely, prosthetic hemiarthroplasty. In most cases, interfragmentary sutures are adequate for fixation. However, if there is not adequate stability, intramedullary Ender's rods or blade-plate fixation can also be used. Hemiarthroplasty is reserved for extensively comminuted 3-part fractures or for patients with poor bone stock.

The vast majority of 4-part fractures are managed with hemiarthroplasty, though ORIF can be attempted in some young, active patients. Up to 90% of 4-part fractures result in avascular necrosis of the humeral head.[7] The goal is to achieve union of the tuberosities to the shaft and to restore rotator cuff function.

With "valgus-impacted" 4-part fractures, the axillary view and the CT can be misleading as the head projects next to the glenoid. The AP is the best radiographic view for visualizing this type of fracture. These fractures have been treated with closed reduction and percutaneous pinning.

A 75-year-old, right-handed woman fell on concrete and presented to the emergency room 2 days later. On examination the sensation over her lateral deltoid was intact. The following x-rays show a 4-part fracture with the head in the axilla. There was no attempt at closed reduction in the emergency room.

A humeral hemiarthroplasty was performed. A retracted supraspinatus tear was identified intraoperatively. The subscapularis was retracted under the strap muscles and the head was anterior to the anteroinferior capsule. The attritional rotator cuff tears were repaired into the tuberosity repair. The following x-ray was obtained postoperatively.

A 56-year-old, right-handed man fell 1 week before presentation. He sustained a 4-part proximal humeral fracture on his left side. He had decreased sensation throughout his hand but normal sensation over the lateral deltoid. The following x-rays were obtained after initial presentation.

Intraoperatively, the head fragment was extracted carefully from its position on the brachial plexus and artery. This was followed by a cemented proximal humeral replacement.

A 54-year-old, right-handed woman was involved in a car accident. She sustained a posterior fracture dislocation. After being informed that she needed a humeral head replacement, she sought a second opinion. Upon examination, it was determined that her arm was locked in internal rotation.

Closed manipulative reduction in the operating room was unsuccessful. As a result, the fragment was reduced open with a bone hook, and the arm moved as a unit. The patient was maintained in a gunslinger brace until healing.

Most proximal humeral fractures are minimally displaced or nondisplaced and can be managed conservatively. Those fractures that are displaced, however, can be a treatment challenge to the orthopaedic surgeon. Successful management of these fractures depends upon a detailed patient history, thorough clinical exam, careful and accurate x-rays, and CT and MRI scans as needed.

Made possible through an unrestricted educational grant from Zimmer.

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....