Mechanisms of Injury
Signs and Symptoms
Imaging and Other Diagnostic Studies
Pathoanatomy and Applied Anatomy
Management of Adverse Outcome and Complications
Authors’ Preferred Method
General Treatment Philosophy
Treatment of Individual Injury Patterns
The great majority of proximal humeral fractures are treated nonoperatively. This includes essentially all nondisplaced fractures as well as most valgus-impacted fractures, especially in patients with lower functional expectations. In patients with higher baseline shoulder function and intrinsically higher expectations, surgical treatment may be recommended for most displaced fractures.30,157,270 Finally, patients with severely displaced and complex proximal humeral fractures are encouraged in most instances to undergo surgery.
In the subset of patients undergoing surgical treatment, we believe that fracture reduction and fixation should be performed in the great majority of cases. In the ideal setting anatomic reduction, with adequate fixation will lead to reestablishing the normal biomechanical relationship between the rotator cuff and a viable humeral head, potentially yielding a close to preinjury level of function. While humeral head necrosis will in most instances adversely affect outcome, partial necrosis may provide an acceptable outcome that is comparable to that of head replacement. We do not feel that based on the current literature, an accurate prediction can be made on what fractures will result in severe humeral head collapse. Results after shoulder hemiarthroplasty have been shown to be highly unpredictable and data on reverse total shoulder arthroplasty is still limited. We therefore consider that every effort should be made to reconstruct the proximal humerus with emphasis being placed on achieving anatomic reduction and stable fixation of the tuberosities. Shoulder arthroplasty is considered in fractures in which a high suspicion of head nonviability is suspected because of severe displacement of the fracture through the anatomical neck without metaphyseal extension, disruption of the medial hinge and frank dislocation from the glenoid. We believe that in technically unreconstructable fractures with fragmentation of the articular surface, arthroplasty should also be considered. In younger patients, hemiarthroplasty is the chosen treatment method. However, in elderly patients, reverse shoulder arthroplasty has become our treatment of choice.
Except for two-part surgical neck fractures, which may be treated with IM nailing, the authors’ preferred method of head preserving reconstruction of the proximal humerus is open reduction internal fixation with a locking screw construct. A deltopectoral approach is used for most open reconstructions, especially arthroplasties. A deltoid split is occasionally used for two-part greater tuberosity fractures and three-part greater tuberosity fractures and is the routine approach when IM nail fixation is planned.
These injuries are almost invariably treated nonoperatively with initial immobilization in a sling. Weekly radiographs and clinical assessment are performed for the first 3 weeks. Elbow, wrist, and hand mobilization begins immediately. Passive range-of-motion exercises are begun at 3 weeks if no change in fracture position has been confirmed. Active-assisted range-of-motion exercises are begun at 6 weeks and strengthening is started at 3 months when bony healing has been confirmed radiologically.
Neer’s criteria of displacement being defined as 1cm of translation or 45 degrees of angulation284,287 have guided surgeons in their management of proximal humeral fractures for many years and historically these were the criteria that many surgeons applied to the treatment of greater tuberosity fractures.116,284 However more recently the currently accepted threshold for surgical treatment of greater tuberosity fractures in active patients has become 5 mm with some authors suggesting that greater tuberosity fractures with 3 mm of displacement should be treated surgically in younger patients who have to undertake heavy overhead activity, such as athletes and laborers.196,245,306,364
Displacement of the greater tuberosity is poorly tolerated because of its key role in shoulder function.39,184 In two-part greater tuberosity fractures the greater tuberosity is displaced posteromedially by the pull of supraspinatus, infraspinatus, and teres minor. Displacement of more than 5 mm has been shown to cause symptomatic malunion364 and to limit abduction and external rotation. As the tuberosity displaces medially it leads to subacromial impingement, which limits abduction, and with posterior displacement abutment of the greater tuberosity against the posterior glenoid will result in limited external rotation. It is in fact likely that shortening of the rotator cuff muscles and altered muscle pull occurs with only minimal greater tuberosity displacement.
Favorable outcomes can be expected when displaced two-part greater tuberosity fractures heal without residual displacement after operative fixation. Flatow et al.116 reported the results of 12 displaced two-part greater tuberosity fractures that were treated by heavy suture fixation and rotator cuff repair through an anterolateral deltoid-splitting approach. All fractures healed without displacement and the authors reported 100% excellent or good results. Similar results have been reported by other authors.92,311 We therefore advocate operative fixation of greater tuberosity fractures which are displaced by more than 5 mm in active patients.
In older, frail patients (usually older than 80 years) with limited functional expectations, a substantial degree of displacement can be accepted without recourse to operative treatment. These patients often have a poor outcome from surgical reduction and fixation, because of their poor bone quality and pre-existing cuff dysfunction, which precludes stable fixation. Although they will often have signs of continued cuff dysfunction from the tuberosity nonunion or malunion, their functional outcome will usually be adequate for their needs.
Operative treatment is advised for physiologically younger patients, who are typically younger than 65 years, active patients with fractures, which are either primarily displaced by more than 5 mm or become displaced by this amount within the first 2 weeks after injury. Selected older patients, usually aged between 65 and 80 years, with fragment displacement of 1 cm or more are offered operative reconstruction. When there is a tuberosity fragment of greater than 2.5 cm open reduction through a limited deltoid-splitting approach and internal fixation using partially threaded cancellous 3.5-mm screws is performed. It is important to insert screws to transfix the fragment to both the humeral head and the medial cortex of the metaphysis. Meticulous repair of any associated rotator cuff injury is also performed.
When the fragment is smaller than 2.5 cm or if it is heavily comminuted, the injury is treated in the same manner as a rotator cuff avulsion. The injury may be treated either with an arthroscopic technique or an open approach. Fixation is obtained either with suture anchors in a double row pattern or by the use of transosseous sutures.116,245 Alternatively, a small T-plate may be fixed laterally onto the proximal humerus with three screws and the horizontal component of the plate used to anchor sutures for tuberosity fixation. This may be of particular use in very osteopenic bone.
Associated Bankart lesions are rare and most frequently occur in younger patients.334 If after tuberosity fixation, the shoulder is found to be unstable when tested intraoperatively, the bony or labral glenoid rim avulsion is repaired.
Isolated lesser tuberosity fractures typically occur in younger or middle-aged patients and are displaced. Nonoperative treatment of these injuries risks later functional incapacity, because of subscapularis dysfunction. It is the authors’ policy to treat all these fractures operatively in medically fit patients. ORIF is performed through a standard deltopectoral approach. If there is a single large fragment, definitive internal fixation is performed using partially threaded 3.5-mm cancellous screws, inserted through the lesser tuberosity.336 Judging accurate screw length (typically between 40 and 50 mm) is an important technical aspect of the procedure, to gain bicortical purchase. If there is comminution associated with a fragment which is 2.5 cm or less screw fixation risks secondary comminution and may not provide sufficient stability. For these patients, the reduction is maintained by transosseous sutures, placed through the bone–tendon junction and through the metaphysis located deep to the fracture bed and lateral to it.336 Frequently, the long head of the biceps is found to be medially dislocated and injured by the fracture fragment. A biceps tenodesis may therefore be considered.
In the minority of patients where the lesser tuberosity fracture is associated with a locked posterior dislocation, an attempt is initially made to obtain closed reduction of the dislocation under anesthesia. Where this is not possible, an open reduction is performed through an extended deltoid-splitting approach. After reduction of the shoulder has been obtained, the stability of the shoulder is assessed throughout a full range of internal and external rotations with the arm at the side and in 90 degrees of abduction. If the shoulder is acutely unstable because of reengagement of a reverse Hill–Sachs lesion on the posterior glenoid beyond neutral rotation, the reverse Hill–Sachs lesion is either elevated and bone-grafted or, if there is a larger defect, filled with piece of shaped femoral head allograft, which is secured with two countersunk 3.5-mm partially threaded cancellous screws or headless compression screws. The lesser tuberosity is then reattached anatomically, using the same techniques as for other isolated two-part fractures, using either two 3.5-mm partially threaded cancellous screws or transosseous sutures.
Almost all fractures in which the shaft is impacted into the surgical neck are treated nonoperatively. A substantial degree of translation of these two fragments is usually tolerated, as long as there is residual cortical contact and impaction. Occasionally, if there is severe varus angulation of the head fragment in a physiologically younger individual (typically younger than 65 years), operative disimpaction, anatomic reduction, and plate fixation will be performed to reduce the risk of later impingement of the greater tuberosity in the narrowed subacromial space and dysfunction of the rotator cuff from its shortened lever arm. In physiologically younger patients, displaced and comminuted surgical neck fractures are managed with ORIF using a locking plate.
An attempt is made to reduce the fracture anatomically whenever possible. It is important to restore continuity of the medial calcar support to prevent acute fixation failure using either structural graft or a low inferomedial screw, which is inserted through the plate. Occasionally, if there is extensive metaphyseal comminution in an older patient, the risk of metaphyseal nonunion is high. If there is extensive metaphyseal comminution shortening and impaction of the shaft fragment within the head is performed to produce a more stable configuration before the plate application. If the bone quality of the humeral head is very poor, a short proximal humeral locked IM nail will often provide more secure fixation than a plate. However, if possible, a locking plate is preferred for definitive fixation to minimize the risk of later rotator cuff dysfunction which is associated with nailing.
Fractures that occur in physiologically older patients should be treated nonoperatively if there is residual cortical continuity of the humeral head fragment on the shaft, the tuberosities are not too widely displaced, and the humeral head appears viable. Although the outcome is often imperfect, after union these patients will usually have a pain-free shoulder, which has sufficient function for their everyday needs.
Operative treatment is offered to physiologically younger patients, where it is thought that the risk of nonunion, cuff dysfunction, or osteonecrosis is high or where operative treatment is likely to provide a significant improvement in shoulder function over nonoperative treatment. In practice, this means that surgery to prevent nonunion or cuff dysfunction is often offered to patients with fractures in which the humeral shaft and tuberosities have significantly displaced from the humeral head. The risk of osteonecrosis is determined by the fracture configuration, with wide displacement of the head from the shaft with probable loss of the medial periosteal and capsular hinge, and the absence of a medial metaphyseal spike particularly associated with a higher risk of this complication. There are substantial functional gains from internal fixation for fractures in which the humeral head has displaced from its normal 130-degree head-shaft orientation to occupy an extreme position of varus (90-degree head–shaft angle) or valgus (180-degree head-shaft angle) or where there is marked humeral head articular surface incongruity from displaced marginal articular fragments attached to the tuberosities.
ORIF is performed whenever possible, and preoperative CT can provide an indication of the likelihood that this will be feasible. The goal is to attempt anatomic or near-anatomic reconstruction. Definitive internal fixation is performed, using a proximal humeral locking plate.
The patient is always preoperatively counseled that if the fracture is deemed to be unreconstructable, an arthroplasty will be performed. In young patients a cemented humeral head replacement will be performed, while a reverse total shoulder arthroplasty will be performed in the older patients.