Shoulder Fractures

Fractures of the shoulder, more specifically the upper (proximal) part of the humerus are common injuries to the skeleton accounting for 4 – 6 % of all fractures, while in seniors over 65 years of age they are the third most common non-vertebral fracture. Their incidence is twice greater in women then in men, while increasing patient age is usually accompanied by increased complexity in fracture patterns. Known risk factors include osteoporosis, diabetes, epilepsy and the female gender. These injuries can occur as a result of both low energy falls, which are more common in elderly osteoporotic patients, and high – energy injuries, as is the case with younger patients.  

A rather unique and important parameter in proximal humerus fractures is the blood perfusion of the humeral head, which, depending on certain criteria such as the degree of fracture complexity, the distance and angle of the bony fragments or the presence of a concomitant shoulder dislocation, may be disrupted leading to ischemia of the humeral head and, in some cases, necrosis. This is essential to bear in mind when deciding the approach strategy of these injuries, as will be explained later on. Furthermore, as the shoulder region is anatomically close to the major blood vessels and nerves of the whole upper arm, associated injuries to these structures can occur together with a shoulder fracture and, thus, must be excluded. 

Fractures of the proximal humerus are classified based on a simple, yet effective method established by Neer and based on the fact that this region develops embryologically from four distinct pats which later fuse together. These are the humeral head, the major and the lesser tuberosity, and the humeral shaft. Fractures are classified as two, three or four –part based on the number of individual fragments to which the humerus has been fractured. Other important classification parameters include the presence of a concomitant shoulder dislocation or that of a head split. 

A patient with a shoulder fracture will present with pain, swelling and inability to move their shoulder. Within a few hours after the injury, bruising will develop in the axilla, chest, arm and elbow, which is often extensive. Standard imaging protocol includes a complete trauma series of plain x-rays involving at least two to three different views of the shoulder. Complex injuries or those involving the chondral surface of the humeral head may also require a computed tomtography (CT) scan to better visualize the individual fragments and their relation in space, so as to guide surgical treatment. 

When deciding on a treatment plan for proximal humerus fractures certain variables have to be taken into consideration.  These include the patient’s biologic age and hand dominance, their level of activity and general medical condition, the fracture characteristics (number of fragments, displacement, type/classification), the bone quality and the presence of associated injuries. For the majority of cases non-operative treatment is feasible, as the healing potential in this anatomic area is great and displacement of less than 0,5-1cm is well tolerated without functional deficit. This involves oral analgesics and immobilization in an arm sling for two to three weeks for comfort, followed by early physical therapy. Early range of motion exercises have been associated with a faster recovery. 

When patient and fracture characteristics preclude conservative treatment, surgical options must be explored. It is important to understand that anesthesia for shoulder surgery is most of the time general (although regional anesthesia techniques can be implemented by a trained physician in certain cases). As such, the patient’s fitness for surgery must be thoroughly assessed pre-operatively. In certain two-part fractures and select few three or four –part closed reduction through manipulation and osteosynthesis using percutaneous (i.e. through very small incisions) pins can be achieved. This technique requires good bone quality and minimal comminution to be present to minimize the risk of loss of reduction and osteosynthesis failure. However, as it involves minimal surgical trauma and generally short surgical time, it can be helpful in patients with borderline displaced fractures who are unable to tolerate more prolonged surgery due to medical comorbidities. 

In biologically young individuals with good to medium bone quality and displaced fractures of any number of parts as well as the young with head split patterns, open reduction and internal fixation using plates and screws is necessary to achieve anatomic bone healing. This is achieved through careful manipulation and reduction as close to their anatomic position as possible of all fracture fragments. In addition, when bone quality is not optimal or severe fracture comminution is present, bone graft can also be used to support the osteosynthesis and fill any residual voids, thus reducing the possibility of loss of reduction. Fracture healing is expected at approximately six weeks, yet physical therapy can be initiated at two to three weeks after surgery by experienced therapists. This involves early passive range of motion exercises, followed by active range of motion and progressive resistance exercises after fracture healing is certified and, finally, advanced stretching and strengthening. 

Another, more minimally – invasive option for biologically young patients with adequate bone quality and appropriately selected fracture patterns is the intramedullary nailing. This technique involves the insertion of a titanium alloy rod from the upper part of the humerus, down its shaft which is interlocked with the addition of screws both proximally and distally. The proximal screws also engage on the separate fracture fragments. This allows for a more biologically – friendly (compared to open techniques) option with good healing rates, which, however, must only be used in select fracture patterns. 

In the event of shoulder fracture – dislocation or head-splitting fractures with unreconstructible patterns in younger patients, or highly complex and comminuted fractures in the elderly, where failure of fixation and avascular necrosis are likely to occur, shoulder arthroplasty is the indicated therapeutic approach. The techniques available involve shoulder hemiarthroplasty and reverse shoulder arthroplasty. The former is used in the biologically young as it reconstructs only one half of the shoulder joint, while it requires anatomic greater and lesser tuberosity healing for optimal outcomes. The latter is reserved for the elderly and lower demand patients with often pre-existing degenerative rotator cuff disease and entails total joint reconstruction with a reverse prosthesis. 

In conclusion, fractures of the proximal humerus are a diverse group of relatively common injuries which can affect people of different biologic age and functionality. They can occur as a result of either low or high energy trauma in various settings and are fairly easy to diagnose. Their treatment varies from conservative, which in some age groups and fracture types is the mainstay, to various types of surgical therapy depending on the fracture and patient characteristics. Outcomes after such injuries depend greatly on the patients’ pre-injury functionality but also on pairing the most safe and effective treatment method to the appropriately selected patient.