Proximal humeral fracture generally occurs in older patients. This is so because older patients have osteopenic or osteoporotic bones which get damaged easily by trivial trauma. High energy trauma can produce these fractures in any person of any age.
Mechanism of Injury of Proximal Humerus Fracture
Most of these fractures occur due to a simple fall on the arm. Strong muscular contraction might be responsible in the setting of electric shock or seizure.
Most fractures are believed to result from indirect violence.
Muscle forces contribute to their displacement. In proximal humerus fracture, pectoralis major draws the shaft of humerus anteriorly and medially. The greater tuberosity may be pulled posteriorly by the infraspinatus and superiorly by the supraspinatus. The subscapularis tends to rotates internally a head segment where lesser tuberosity remains attached.
Clinical Presentation of Proximal Humerus Fracture
Most patients with acute proximal humerus fracture present with a painful, swollen arm. There could be bruises over the injured area or they might develop over a period.
Apart from the injured area that patient has presented with, the patient should be assessed for neck and chest injury. It goes without saying that distal limb should be examined for any neurovascular involvement.
The most commonly injured nerve in proximal humerus fracture is the axillary nerve.
If the patient has amnesia, bilateral injuries, or a posterior fracture-dislocation, a seizure disorder or electric shock must be ruled out.
Imaging of Proximal Humerus Fracture
The ordered radiographs for these fractures must include anteroposterior view of the scapula, a lateral “Y-view” of the scapula, and an axillary view.
If a good radiograph fails to detect anything CT scans are most helpful in checking for dislocations, in ruling out a glenoid fracture, and in assessing posterior retraction of the greater tuberosity.
Classification of Proximal Humerus Fracture
Most commonly used classification method of proximal humerus fracture is that of Neer’s. Fractures are classified by evaluating displacement of any of the four principal fragments (head, shaft, greater tuberosity, and lesser tuberosity).
All fractures in which no segment is displaced more than 1 cm or is rotated more than 45 degrees are considered minimally displaced and are considered together as one-part fractures, regardless of the number or location of fracture lines.
A single segment is displaced in a two-part fracture. This occurs most commonly with surgical neck displacement, in which the shaft is separated from the head and both attached tuberosities. It is also seen seen with greater tuberosity displacement.
A fracture with three-part displacement has the shaft and either the greater (most often) or lesser (rarely) tuberosity separated from the head, to which one of the tuberosities remains attached.
A four-part fracture is present when the head is separated from all other segments, even if the tuberosities are together (thus, there can be three pieces, one of which comprises both tuberosities). The head is completely dislocated out of the glenoid and is devoid of any soft tissue attachment. In the “valgus-impacted” four-part fracture, the head is rotated to face upward Although the head is completely out of contact with the glenoid.
If the head is split or has suffered an impression fracture, it is considered to have articular loss.
Three Part Proximal Humerus Fracture
Three part fractures involves a fracture of surgical neck of humerus along with fracture of either greater tuberosity or lesser tuberosity. While surgical neck is quite displaced to miss out, small degree of tuberosity displacement may be easily missed and may require additional radiographic views.
Open reduction and internal fixation is the preferred treatment. Failure of the treatment may lead to hemiarthroplasy i.e. replacement of head component with prosthesis.
Four Part Proximal Humerus Fracture
In this injury, there is fracture of the head which results in its separation from rest of the structures and there are fractures of lesser and greater tuberosities. Very often, the head is dislocated anteriorly, laterally, or posteriorly. The greater and lesser tuberosities are not always separated, and they may be held together by muscle attachments.
This injury is best shown by anteroposterior views. A computed tomogram clearly delineates the fracture.
Four-part fractures have not done well with nonoperative treatment and repaired fractures do better than nonoperative cases.
Historically, results of surgery of four part fractures have not been found good but improved techniques of fixation and better patient selection have brought better results.
Avascular necrosis of the head is a significant problem in these fractures.
Displaced Fractures of Tuberosity
Fracture of greater tuberosity is commoner than lesser tuberosity.
The greater tuberosity is displaced superiorly by the supraspinatus or posteromedially by the infraspinatus and teres minor. In lesser tuberosity fractures on the other hand, displacement tends to be medial because of the pull of the subscapularis.
7% to 15% of glenohumeral dislocations have an associated greater tuberosity fracture.
Treatment of Proximal Humerus Fracture
Proximal humerus fracture, in quite number of cases can be managed with non operative treatment. The principle of treatment by conservative methods is early protection combined with gradual mobilization.
Elderly people accept non operative treatment quite well. Even deformities like displacement and angulation are taken very well by these patients.
Most patients are placed in a sling for the first week to 10 days. Closed reduction of surgical neck fracture may be attempted in patients who would tolerate it. Hand, wrist, and elbow motion begins immediately. Radiographs are done after 3 or 4 weeks. If the fracture configuration has not worsened and the feel is solid, gentle assistive exercises like pulley elevation, external rotation with a stick, extension with a stick are begun along with formal physical therapy.
Gradual stretching exercises are also begun and continued till maximum range of motion is achieved.
Indications for Nonoperative Treatment of Proximal Humerus Fracture
- <5mm of superior or 10 mm of posterior greater tuberosity displacement in active people
- <10 mm of superior displacement in non dominant arm of sedentary paients
- Any kind of bony contact in elderly patients in case of elderly patients and less than half shaft diameter displacements and less than 45 degree angulation in dominant arm in young people.
- Lesser demands and expectation of the patient
- If the patient is unable to tolerate surgery and anesthesia
- The patient is too weak to pursue rehabilitation or not able to understand or remember postoperative instructions.
Surgical Treatment of Proximal Humerus Fracture
Different methods of fixation of proximal humerus fracture include
- Closed reduction
- Closed reduction and percutaneous fixation
- Open reduction with internal fixation
- Humeral head replacement
Greater tuberosity fractures, 2-part
Displacement of greater tuberosity fractures usually is posterior and superior. Attempts at closed reduction are unsuccessful, except in cases with an associated anterior dislocation, in which closed reduction of the fragment may be adequate.
Open treatment is recommended for greater tuberosity fractures displaced 5 mm or more.
Lesser tuberosity fractures, 2-part
Displacement of the lesser tuberosity often is medial, and closed reduction with internal rotation often can place the tuberosity in satisfactory position. Therefore, open treatment of these fractures may not be necessary.
Surgical neck fractures, 2-part
Closed reduction, closed reduction and percutaneus pinning and open reduction and internal fixation with precontoured proximal humerus locked plates can be considered.
Anatomic head fractures, 2-part
This rare injury can occur in conjunction with humeral head dislocation. In general, it has a very guarded prognosis because of the compromised blood supply to the head segment.
Elderly patients with poor tissue quality and osteoporosis usually require arthroplasty. In younger patients, every effort should be made to retain the humeral head. Possibility of hemiarthroplasty or reverse shoulder arthroplasty in case the decision is made intraoperatively that fixation seems inadequate.
These fractures require open surgical management in line similar to three part proximal humerus fracture
Complications of Proximal Humerus Fracture
This usually results from muscle atony, blood in the joint, capsular tears, or any combination of these conditions. Treatment consists of sling support, deltoid isometrics, and observation. Instability should not be ignored.
Incorrect diagnosis, poor reduction, inadequate fixation are frequent causes of malunion. Treatment depends on severity of the malunion. For less severity, the malunion can be left as such. Sevre malunions can be treated by release of adhesions with or without osteotomy. Trimming of prominences can also be considered.
Non union is rare in proximal humeral fractures. Early motion and poor bone stockare the fequent causes. It should be treated by surgical methods including humeral head replacement when necessary.
it is more common in three part and four part fractures. Most patients are followed and watched. Gentle stretching exercises and mild analgesics are the usual tratment inmost patients. If collapse occurs or pain becomes unbearable, humeral head replacement is considered. In case of development of glenoid arthritis, a total shoulder replacement considered.
Due to large envelope of soft issues infection in shoulder has a low rate. ANtibiotics, debridement and regular wound care are the basic management techniques.
As many as 45% of patients with surgical neck fractures or glenohumeral dislocations have been found to have some degree of nerve injury. The risk is more in elderly patients or when a hematoma develops.
When associated with closed fracture, the prognosis for recovery is good, and observation is indicated. Splints may be used to support weak joints, and therapy is used to maintain passive motion.
Arterial injury from displaced fractures is common.
Could occur following avascular necrosis or hardware penetrating joint.
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