Intramedullary Fixation of Proximal Humerus Fractures

DEFINITION

Fractures of the proximal humerus can be two, three, or four part according to the Neer classification (FIG 1).

Fifty percent to 80% of proximal humerus fractures are nondisplaced or minimally displaced and stable.A short period of immobilization in neutral rotation to avoid fracture malunion followed by early mobilization is usually sufficient to treat fractures and can result in satisfactory outcomes.

Twenty percent to 50% of patients with displaced, unstable two-, three-, four-part proximal humerus fractures with a vascularized, attached head fragment may benefit from operative management with reduction and internal fixation.

Extensive dissection and inadequate biomechanical fixation in the context of the severe soft tissue injury, osteopenia, and devascularization associated with these complex fracture types are the commonly cited reasons for failure of internal fixation devices.

Encouraging reports have been made on the use of intramedullary nails for two-,three-, and even select four-part fractures. Newer designs of intramedullary nails that permit stable fixation of the head to the shaft of the humerus while maximizing biomechanical fixation of the tuberosities using a minimally invasive rotator cuff-splitting approach are ideal.

Techniques in this chapter use the Aequalis intramedullary nail (Tornier, Inc., Bloomington, MN). This is an intramedullary stabilization device for proximal humeral fractures, designed specifically to optimize tuberosity fragment fixation and provide stable support for the humeral head, improving proximal humeral reconstruction and fixation in osteopenic bone.

 

ANATOMY

Osteology

 

The proximal humerus includes the humeral head, the lesser tuberosity (LT), the greater tuberosity (GT), and the proximal humeral metaphysis.

 

The position of the head is higher than the tuberosities, and changes in this relationship will cause poor biomechanical function. The humeral head is slightly medial (3 mm) and posterior (7 mm) in relation to the humeral shaft (FIG 2).

 

The humeral head is retroverted approximately 30 degrees (range 20 to 60 degrees).

 

The bicipital groove separates the lesser and greater tuberosities. The hardest bone in the proximal humerus is located within the bicipital groove and most fractures of the GT occur posterior to the groove.

Vascular Supply of the Proximal Humerus

 

The anterior and posterior humeral circumflex arteries are branches of the axillary artery.

 

 

The arcuate artery, the terminal vessel of the ascending branch of the anterior humeral circumflex artery, supplies most of the humeral head.

 

 

Avascularity of the humeral head can occur if this vessel is disrupted during a fracture of the anatomic neck.

 

The posterior circumflex artery becomes important in patients with proximal humerus fractures.

 

 

It may be the primary source of blood supply to the fractured head, so care should be taken to prevent additional devascularization.

 

 

Traumatic and iatrogenic vascular insult may lead to devascularization of the fracture fragments, resulting in delayed union, nonunion, and avascular necrosis. Traumatic injury cannot be prevented; well-planned minimally invasive procedures should reduce the risk of further damage, however.

 

Innervation

 

The brachial plexus is at risk in patients with upper extremity injury, and thorough neurologic evaluation is mandatory.

 

The axillary nerve courses through the quadrilateral space, where it is at risk during fracture dislocation.

 

The lateral entry site for locking screw fixation (4 to 5 cm distal to the tip of the acromion) places the axillary nerve at risk.

 

PATHOGENESIS

 

 

A blow to the anterior, lateral, or posterolateral aspect of the humerus typically is the cause. Axial load transmitted to the humerus may cause impacted fracture in osteoporotic bone.

 

Violent muscle contractures, as in grand mal seizures and electric shock, are associated with posterior dislocation- and impaction-type fractures due to overpowering internal rotators and adductors.

 

 

Pathologic causes include tumor, multiple myeloma, and metastatic or metabolic disorders. Osteoporosis is associated with fractures of the proximal humerus (more than any other fracture).

 

Minor losses in the humeral length between the head and the deltoid insertion can alter the deltoid length-tension ratio.

 

In unstable three- and four-part fractures, displacement occurs because of the pull of the rotator cuff muscles on their attached tuberosities in the transverse plane, widening the gap created by the fracture plane posterior to the bicipital groove. The GT is pulled posteromedially by the

 

P.3741

infraspinatus and teres minor muscles, whereas the LT is pulled anteromedially by the subscapularis muscle (FIG 3).

 

 

 

FIG 1 • Classification of shoulder fractures according to Neer. Fracture patterns that are shaded in blue are amenable to humeral nailing.

 

 

In four-part proximal humerus fractures, it has been demonstrated that the main vertical fracture plane separating the tuberosities is located posterior to the bicipital groove and that the principal displacement of such fractures occurs in the transverse (horizontal) plane (FIG 4).

 

In fractures involving the loss of reduction and fixation of the GT leads to definitive retraction and atrophy of the two single external rotator muscles of the shoulder (infraspinatus and teres minor).

 

 

Results in definitive pseudoparalyzed and stiff shoulder for which surgical options are limited.

 

By contrast, posttraumatic humeral head necrosis is well tolerated if the GT has healed in an anatomic position and there is no screw penetration or glenoid erosion. Thus, all efforts of the surgeon should not be directed toward the humeral head but to the GT fixation and reduction.

 

The humeral head becomes stable when both tuberosities are reduced and fixed.

 

Modern intramedullary nails have been designed specifically to optimize tuberosity fragment fixation and provide stable support for the humeral head, improving proximal humerus reconstruction and fixation in osteopenic bone. The design of these nails and these specific techniques have been created to avoid the common complications

 

P.3742

and problems related to previous intramedullary nailing of proximal humeral fractures.

 

 

 

 

FIG 2 • Normal shoulder anatomy. The head is slightly higher than the tuberosities, slightly medial and posterior to the humeral shaft, and retroverted 30 degrees. (Copyright J. Dean Cole, MD.)

 

NATURAL HISTORY

Epidemiology

 

Four percent to 5% of all fractures

 

Increased incidence in osteoporosis, older middle-aged and elderly persons (third most common fracture in elderly)

 

In persons older than 50 years of age, the female-to-male ratio is 4:1 (osteoporosis). Minor falls and trauma may cause comminuted fracture.

 

In patients younger than 50 years of age, violent trauma, contact sports, and falls from heights are responsible for fractures.

 

Surgical neck fracture is common.

 

Consequences of Injury

 

 

Nondisplaced fractures may heal without major consequences. Acute, recurrent, or chronic dislocation

 

Rotator cuff tears

 

 

 

 

FIG 3 • A. Fracture pattern and deforming forces. The muscular attachments of the GT and LT will cause abduction, external rotation, and internal rotation, respectively. The head will follow whichever tuberosity is intact. B,C. In four-part fractures, the head often is in a neutrally rotated position. (Copyright J. Dean Cole, MD.)

 

 

Neurovascular injury: axillary nerve, brachial plexus

 

Avascular necrosis of the humeral head can result from disruption of the arcuate artery. The axillary artery also may be damaged but less commonly.

 

Malunion

 

 

Malunion of the tuberosities causes poor shoulder function due to altered biomechanics.

 

Shortening may cause poor shoulder function due to changes in the length tension relationship of the deltoid.

 

 

 

 

Posttraumatic arthrosis Adhesive capsulitis Biceps tendinopathy Chronic pain

PATIENT HISTORY AND PHYSICAL FINDINGS

 

Associated injuries

 

 

 

Rotator cuff tears Dislocation Forearm fractures

 

Brachial plexus, axillary, and radial and ulnar nerve injuries (5% to 30% of complex proximal humerus fractures)

 

Biceps tendon injury/entrapment

 

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

Trauma series

 

 

 

Scapular anteroposterior (glenoid view) Trans-scapular

 

 

Axillary Rotational views

 

Computed tomography (CT) scan is very helpful to characterize the fracture fragments and aid in surgical

planning.

 

SURGICAL MANAGEMENT

 

Indications

 

 

Displaced or unstable two-, three- and certain four-part proximal humerus fractures.

 

Prerequisites

 

 

Shoulder table, image intensification, and experienced radiology technician

 

Be aware of the learning curve (do not attempt nailing of a four-part fracture before acquiring adequate experience with two- and three-part fractures).

 

 

P.3743

 

 

 

FIG 4 • Plain radiographs (A,B), CT (C-E), and CT with three-dimensional (3-D) reconstruction (F-H) of a valgus impacted four-part fracture. Note the fracture line is posterior to the bicipital groove for the GT fracture.

 

 

When treating patients with complex fractures, obtain the patient's consent for a hemiarthroplasty and/or reverse shoulder arthroplasty if these treatments are determined to be the best treatment and have the implant available in case it is found to be necessary.

 

Contraindication: head-splitting, comminuted displaced humeral head fragment devoid of soft tissue attachments

 

Preoperative Planning

 

Successful intramedullary nailing of the proximal humerus fracture depends on consistent integration between image intensification and the surgical steps.

 

 

Patient positioning on a radiolucent table will allow the surgeon to use a minimally invasive approach. Errors in the nail entry site will cause inevitable problems with the rest of the procedure.

 

It is crucial that the surgeon follow the surgical technique precisely.

Positioning

 

Positioning on the table must allow orthogonal and overhead axillary views.

 

The patient is placed supine in the beach-chair position with the elbow flexed 90 degrees on a radiolucent table tilted at 60 to 70 degrees. The C-arm should be positioned to allow the surgeon easy access to the proximal humerus (FIG 5).

 

A bolster may be used to elevate the shoulder from the table and to allow shoulder extension. Extension of the shoulder aids in exposure to the entry site in the humeral head.

 

Approach

 

Each type of proximal humerus fracture (two-, three-, fourpart) has its own pathophysiology and complications. The surgical technique must therefore vary accordingly. Threedimensional CT scan images reveal the exact fracture geometry and allow accurate preoperative planning.

 

 

P.3744

 

 

 

 

FIG 5 • Patient positioning should allow access of the C-arm to obtain adequate radiographs.

 

 

Three surgical approaches are possible depending on the fracture type and the surgeon's preference:

 

 

The percutaneous approach, in which the deltoid muscle and supraspinatus are bluntly split through a superior, 1-cm incision, is used most frequently for two-part fractures not requiring tuberosity fixation.

 

The superior transdeltoid approach, in which the anterior head of the deltoid is detached from the anterior acromion with the tip of the acromion to expose the rotator cuff, is used most often if the GT is involved.

 

The deltopectoral approach, in which the anterior deltoid muscle is retracted to expose the rotator cuff, can be used in three-part fractures involving the LT.

 

This chapter will describe the superior transdeltoid approach to fix a valgus impacted four-part fracture and the percutaneous approach for a two-part fracture. The technique is easily adapted for three-part fractures involving only one of the tuberosities.

 

For all approaches, the straight nail must be inserted medially either through the supraspinatus muscle fibers or through the rotator interval. The entry portal of the nail is created with an awl and enlarged with a reamer under fluoroscopic control. If the bicipital groove is fractured, the long head of the biceps should be tenodesed to avoid postoperative pain and stiffness.

 

TECHNIQUES

  • Four-Part Valgus-Impacted Fracture with a Superior Transdeltoid Approach

 

A saber incision in line with Langer lines is planned and created to expose the division of the anterior and middle deltoid (TECH FIG 1A). This division is found just lateral to the anterior edge of the acromion.

 

A split is made between the anterior and middle deltoid fibers with a cautery with the arm in slight abduction to help relax the deltoid. The saw is used to create an osteotomy of the anterior acromion, which will allow exposure for nail entry and facilitate later repair. The osteotomy is completed with an osteotome. The deltoid is split no more than 4 cm from the acromion to avoid injury to the axillary nerve. The saber incision helps to avoid splitting the deltoid distally to prevent this from happening. Gelpi selfretaining retractors help to facilitate the exposure (TECH FIG 1B).

 

A Hohmann retractor is placed over the coracoid to help gain exposure for bursal resection. The bursa is excised to expose the GT, LT, and head fracture fragments. Great care is taken to stay below the deltoid fascia to avoid injury to any branches of the axillary nerve (TECH FIG 1C).

 

The fracture is identified and then the fibers of the rotator cuff can be incised longitudinally to expose the head fragment if needed (TECH FIG 1D).

 

 

 

TECH FIG 1A • Landmarks and skin incision for a superior transdeltoid approach have been drawn out. A saber incision in line with Langer lines is made (red arc). It is centered over the division between the anterior and middle deltoid (green line). The blue arrow is the site of the acromial osteotomy, which facilitates the deltoid repair at the end of the case.

 

 

The biceps tendon is identified and tenodesed to the overlying soft tissue. The biceps tendon may be entrapped within the fracture fragments. Stay sutures help to facilitate retraction of the cuff split to permit exposure and reduction of the fracture (TECH FIG 1E).

 

The head fragment must be elevated out of valgus. This is accomplished by freeing up the fracture

fragments with a Steinmann pin or similar elevator. The humeral head can then elevated out of its valgus position with an impactor (TECH FIG 1F).

 

Next, the “book” can be closed with the previous sutures placed through the supraspinatus and subscapularis as the GT and LT are brought together supporting the humeral head reduction. The reduction of the fracture fragments is palpated with a forceps to confirm fracture lines have been opposed. The reduction is held with a pointed reduction forceps. Next, a pin is introduced into the humeral head posterior to the eventual path of the nail but allowing stabilization of the reduction of the head to the glenoid (TECH FIG 1G).

 

The awl can then be introduced into the humeral head with a twisting motion straight in line with the humeral shaft. The entry point is just posterior to the bicipital groove and medial to the insertion of the rotator cuff. This articular cartilage does not articulate with the humeral head and allows preservation of the rotator cuff insertion. After the awl is introduced, the guidewire can be placed and correct positioning confirmed with fluoroscopy (TECH FIG 1H).

 

P.3745

 

 

 

 

TECH FIG 1B • B1. A split is made between the anterior and middle deltoid fibers. A saw (B2) and

osteotome (B3) are used to osteotomize the anterior acromion to facilitate later repair. B4. The deltoid is split no more than 4 cm from the acromion to avoid injury to the axillary nerve.

 

 

The awl is removed and the humeral head reamed to accept the nail. The reamer is only used to expand the proximal humerus for the proximal portion of the nail. The nail is introduced with the jig and seated to the etch mark on the guide which will seat the nail below the humeral head. A pin is inserted into the lateral side of the jig to ensure the proper depth of insertion which is also confirmed under fluoroscopy (TECH FIG 1I).

 

 

 

TECH FIG 1C • Bursal adhesions are removed to facilitate exposure of the fracture. One must dissect below the deltoid fascia in order to avoid injury to branches of the axillary nerve.

 

 

The version of the humeral head and its position relative to the tuberosities must be checked. This is uniquely accomplished with this particular system with an outrigger attachment that is aligned to the forearm (TECH FIG 1J).

 

At this point, the distal screws can be inserted to secure the nail within the intramedullary canal and lock the nail in its correct orientation within the medullary canal and height below the

 

P.3746

articular cartilage. A calibrated drill is inserted through trocars that are inserted into the guide, which ensures correct targeting and position of the screws and avoids injury to neurovascular structures. The near cortex is drilled and far cortex can be palpated by tapping the drill. The drill is measured after penetration of the lateral cortex. The correct length screw is then inserted through the trocar and screwed in place. As the screw is advanced through the nail, the polyethylene locking mechanism can be felt to engage the screw (TECH FIG 1K). A second diaphyseal screw can then be placed in a similar manner.

 

 

 

TECH FIG 1D • The fracture is identified by the blue arrow after the bursa has been removed. The fibers of the rotator cuff are split longitudinally. Fracture hematoma is expressed from the joint upon entry.

 

 

Next, the proximal GT screws can be placed. Again, the trocars are inserted through the guide sleeves and advanced to the cortex. By applying pressure to the outermost trocar (the trocar nearest the guide), the inner trocars can be seen to “back out” as they are advanced against the cortex. This ensures the drill sleeve is directly against the bone. The outer cortex is then drilled. There is no need to drill the inner cortex, as the screws are captured within the locking mechanism of the nail. This ensures that the screws will not penetrate the head errantly. When the drill is advanced past the nail, it is replaced with the appropriate-sized screw. One or two screws may be placed in the GT (TECH FIG 1L).

 

 

 

TECH FIG 1E • The biceps tendon is identified and tenodesed to the overlying soft tissue. Stay sutures help to facilitate retraction of the cuff split to permit exposure and reduction of the fracture.

 

 

The LT screw is then placed proximally in a similar manner to complete the construct. The arm is internally and externally rotated, and screw position is confirmed with fluoroscopy (TECH FIG 1M).

 

Finally, the split in the rotator cuff is repaired with side-to-side sutures. The hole in the humeral head will be covered with fibrocartilage and will not articulate with the glenoid. The acromial osteotomy and deltoid split are then repaired and the skin closed routinely (TECH FIG 1N).

 

P.3747

 

 

 

TECH FIG 1F • A Steinmann pin is introduced through the fracture site to free up the fracture fragments and allow reduction of the humeral head. An impactor can be introduced into the fracture to further facilitate this reduction. Image intensification is used to confirm reduction.

 

 

 

TECH FIG 1G • The book of the GT and LT are closed over the humeral head with a pointed reduction forceps. The forceps is in line with the fracture fragments and confirms the fracture lines have been closed. A pin is introduced into the humeral head posterior to the path of the nail but allowing stabilization of the reduction of the head to the glenoid.

 

 

P.3748

 

 

 

TECH FIG 1H • The awl is introduced into the humeral head with a twisting motion straight in line with the humeral shaft and the guidewire introduced through the awl into the shaft. This is confirmed with fluoroscopy.

 

 

 

TECH FIG 1I • The awl is removed and the humeral head reamed to accept the nail. The nail is introduced and seated to the etch mark on the guide which will seat the nail below the humeral head. A pin is inserted into the lateral side of the jig to ensure the proper depth of insertion which is confirmed under fluoroscopy.

 

 

 

TECH FIG 1J • The version of the humeral head is checked with the outrigger attachment, which is placed parallel to the forearm. This will ensure correct version of the nail to the humeral head and tuberosities.

 

 

P.3749

 

 

 

TECH FIG 1K • The distal screws are inserted first to secure the nail within the intramedullary canal. The calibrated drill is inserted through the guide and depth measured after penetration of the lateral cortex. The drill is advanced with a tapping motion to “feel” the opposite cortex prior to penetration to ensure accurate measurement. The correct length screw is then inserted through the trocar. Again, there is an etch line to ensure the proper depth of insertion. As the screw is advanced through the nail, the polyethylene locking mechanism can be felt to engage the screw.

 

 

 

TECH FIG 1L • The GT screws are then placed proximally. These are again advanced through the trocars. The skin incision can be retracted to avoid placing an additional incision on the skin. The anterior cortex is again drilled and the screw inserted through the trocar.

 

 

P.3750

 

 

 

TECH FIG 1M • The LT screw is then placed proximally. The arm is internally and externally rotated, and screw position is confirmed with fluoroscopy.

 

 

 

TECH FIG 1N • The split in the rotator cuff is then repaired with side-to-side sutures. The hole in the humeral head is just visible below the split with the nail well below the surface. The acromial osteotomy and deltoid split are then repaired and the skin closed.

  • Three-Part Greater Tuberosity Fractures with Malrotation with Superior Transdeltoid Derotation Approach

     

    In three-part (GT) fractures, the head fragment is internally rotated due to traction of the subscapularis muscle and the absence of the counteracting force of the infraspinatus and teres minor due to the avulsed GT and the diaphysis is displaced medially and anteriorly.

     

    The main goal is to derotate the head fragment and anatomically reduce and fix the GT, which will effectively convert the three-part fracture into a two-part fracture.

     

    The “derotation” technique can be accomplished before or after nail insertion.

     

    Prior to nail insertion, sutures are used to control the head fragment and LT and the GT fragments which are attached to the subscapularis and supraspinatus and infraspinatus, respectively (TECH FIG 2A).

     

    Alternatively, the nail can be inserted and the head fragment, which is in excessive internal rotation, can be derotated using

     

    P.3751

    either a suture placed in the subscapularis or a bone hook inserted through the incision.

     

     

     

     

    TECH FIG 2A • Placement of sutures into the rotator cuff to “derotate” three-part fractures prior to nail placement. Sutures are placed in the LT and GT and the fragments manipulated for the proper reduction (blue arrow is site of reduction of the LT and head fragment to the GT). Alternatively, a bone hook or Steinmann pin may be inserted after nail placement to bring the GT around the nail and then GT screws placed converting the fracture into a two-part fracture. Compression in this instance would be obtained by placing upward pressure on the elbow, followed by locking screw placement distally.

     

     

    Following derotation, the version rod is placed in internal rotation and the anterior screw is inserted in the LT (TECH FIG 2B).

     

    With the LT and head now captured by the nail construct, the epiphyseal fragment can be rotated externally with the help of the external jig and the GT is manipulated using either a hook or a suture placed in the infraspinatus.

     

     

     

    TECH FIG 2B • Placement of a screw into LT to secure it to the nail. Sutures are in the GT to bring it around to the LT. Alternatively, a bone hook may be used through the incision.

     

     

    Once anatomic reduction is achieved, it is fixed with screws, converting the three-part fracture into a twopart surgical neck fracture.

     

    This surgical neck fracture is then reduced by aligning the version rod to the forearm, which is placed in neutral rotation. Finally, compression at the fracture site is given by impacting the elbow, and the two distal screws are inserted.

  • Two-Part Surgical Neck Fracture with a Percutaneous Approach

 

In two-part (surgical neck) fractures, the epiphysis is correctly oriented and has a fixed position because the internal rotator and external rotator muscles are still attached and balanced. The diaphysis is medially displaced (due to the medial pull of the pectoralis major, latissimus dorsi, and teres major) and in internal rotation (because the forearm is usually held against the belly) (TECH FIG 3A).

 

Two main complications are specifically encountered with twopart (surgical neck) fractures and must be anticipated:

 

Rotational malunion occurs when the nail is locked proximally and distally with the arm in internal rotation; this leads to decreased humeral retroversion and, consequently, external rotation.

 

Avoided by using the outrigger alignment guide as described earlier

 

 

P.3752

 

 

 

TECH FIG 3A • Two-part surgical neck fracture. The diaphysis is pulled medially in relationship to the head fragment. This head fracture in this instance has some extension and minimal varus angulation.

 

 

Surgical neck nonunion occurs in cases of persistent distraction at the fracture site.

 

Avoided by a backslap technique: consisting in retrograde hammering after distal locking, which impacts the surgical neck fracture site, preventing nonunion

 

Fluoroscopy is used in the same way for the percutaneous technique as it was for the four-part fracture.

 

The starting point is located for the percutaneous technique either anterior or posterior to the acromioclavicular joint. The posterior location or the “Nevasier” portal is preferred in instances where the head fragment has varus angulation (TECH FIG 3B).

 

After locating the starting point under fluoroscopy with a spinal needle, an incision is made, which is large enough to allow eventual passage of the humeral nail. A blunt Kelly forcep is used to spread the muscle fibers down to the humeral head. The tendon lies lateral to the starting point and is thus spared injury.

The patient's arm is held in neutral rotation during this step to help with rotational alignment (TECH FIG 3C).

 

The awl is then introduced into the incision and with a twisting motion and downward pressure advanced into the humeral head. The awl can then be used to manipulate the head fragment and allow for the passage of the guidewire. The guidewire is inserted through the awl, and image intensification is used to confirm the awl and guidewire position (TECH FIG 3D).

 

 

 

TECH FIG 3B • The starting point for the percutaneous technique can be located anterior (red dot) or posterior (yellow circle identified by the mosquito forcep) to the acromioclavicular joint. The posterior location or the Nevasier portal (yellow circle) is preferred in instances where the head fragment has varus angulation.

 

 

The cannulated reamer is used to open the proximal portion of the bone, and the nail is inserted with the attached targeting jig. The depth of the nail is confirmed under fluoroscopy using a Kirschner wire (K-wire) through the lateral side of the jig. It is inserted somewhat more distally than for three- or four-part fracture types to allow for backslapping and compression. The K-wire should be below the level of the head to ensure the proper depth (TECH FIG 3E).

 

As with the multipart fractures, the diaphysis is independent of, and can be rotated around, the head fragment. In order to obtain the correct reduction, a version rod “outrigger” is attached and aligned with a supinated forearm. This allows for the correct position of the diaphysis relative to the humeral head, which is again confirmed under fluoroscopy. The distal trocars are then introduced and drilled with a calibrated drill and the correct screws placed statically and confirmed under fluoroscopy (TECH FIG 3F). Dynamic distal fixation of the nail is not necessary, as the upper limb is subjected to more distraction rather than compression forces (as the femur or tibia). This may, in part, explain the rate of nonunion after surgical neck fracture.

 

The second screw ensures that the nail is centered within the diaphysis. Following screw placement distally, the slap hammer can be attached to the nail and by “backing the nail out” used to compress the fracture fragments. The top of the slot in the guide should be level with the top of the humeral head and fluoroscopy used to confirm compression at the fracture site. Overall compression is about 10 mm. The outrigger ensures correct rotation is maintained during compression (TECH FIG 3G).

 

Next, the tuberosity screws are placed superiorly to lock the distal and proximal fragments in the correct orientation. A similar approach is used superiorly by placing trocars through the guide sleeves followed by drilling, screw placement, and confirmation via fluoroscopy. The version rod is again used to ensure the proximal segment does not shift relative to the distal segment, but once a single screw is placed, the rotation is locked at this point. Usually, a single screw is enough for a two-part fracture, but a second screw is also optionally added. The fluoroscopic images again confirm screw placement (TECH FIG 3H).

 

The proximal guide is removed and the final fluoroscopic images made to confirm the compression and appropriate rotation of the entire humerus with external and internal rotation images. These can be done under “live” fluoroscopy (TECH FIG 3I). The skin is closed routinely.

 

P.3753

 

 

 

TECH FIG 3C • A needle is used to locate the starting position medial to the tuberosity and within the head. A stab incision is created to allow passage of the awl and nail. The incision is spread with a Kelly forcep.

The position of the arm is at the patient's side during this step.

 

 

 

TECH FIG 3D • The awl is introduced into the incision and advanced into the humeral head. The awl can be used to manipulate the head fragment and allow for the passage of the guidewire. Image intensification is used to confirm the awl and guidewire position.

 

 

 

TECH FIG 3E • The cannulated reamer is used to open the proximal portion of the bone, and the nail is inserted with the attached targeting jig. The depth of the nail is confirmed under fluoroscopy using a K-wire through the lateral side of the jig. The K-wire should be below the level of the head. When compression is used, the nail should be countersunk approximately 10 mm below the articular cartilage.

 

 

P.3754

 

 

 

TECH FIG 3F • As in the four-part fracture, the diaphysis can be rotated around the head fragment. In order to obtain the correct reduction, the version outrigger is attached and aligned with a supinated forearm. This allows for the correct position of the diaphysis relative to the metaphysis, which can be confirmed under fluoroscopy. The distal trocar is then introduced, drilled with a calibrated drill, and the correct screw placed through the trocar and length confirmed again under image intensification.

 

 

 

TECH FIG 3G • The second screw is placed centralizing the nail in the diaphysis. The slap hammer is applied and used to compress the fracture fragments. The top of the slot should be level with the top of the humeral head and fluoroscopy used to confirm compression at the fracture site.

 

 

P.3755

 

 

 

TECH FIG 3H • The tuberosity screws are then placed superiorly. A similar approach is used by placing trocars through the guide sleeves followed by drilling, screw placement, and final fluoroscopic images. The version rod is used to ensure the proximal segment does not shift relative to the distal segment, but once a single screw is placed, this can be removed, as the rotation is set at this point. The fluoroscopic images confirm screw placement.

 

 

 

TECH FIG 3I • The final fluoroscopic images confirm excellent compression and appropriate rotation of the entire humerus with external and internal rotation images or live fluoroscopy.

 

 

PEARLS AND PITFALLS

 

P.3756

 

 

 

 

Indications

  • Two-part proximal humerus fracture

  • Three-part proximal humerus fracture

  • Select four-part proximal humerus fracture

 

 

 

Prerequisites ▪ Shoulder table, image intensification, and experienced radiology technician

  • Be aware of the learning curve.

  • Plan B: For complex fractures, obtain consent for a hemiarthroplasty or reverse arthroplasty and have an implant available.

 

Contraindication ▪ Head-splitting, comminuted displaced humeral head fragment devoid of soft tissue attachment

 

Positioning ▪ Beach-chair position to allow clear fluoroscopic images

 

Reduction technique

  • Fracture fragments for four-part fractures are freed and disimpacted and reduced with an impactor. Use K-wire to hold position by pinning to the glenoid.

  • Three-part fractures can be reduced with sutures or bone hook secured, derotated, and converted into a two-part fracture.

  • Orthogonal views of the shoulder

     

    Nail entry site ▪ Erring at the entry site inevitably will cause problems with the rest of the procedure.

     

    Screw placement

  • A drill guide is used to prevent injury to the nerves and long head of the biceps.

     

    Orientation ▪ An outrigger guide helps maintain the proper rotation and version of the epiphyseal to the metadiaphyseal segments.

     

    Pitfalls ▪ Rotational malunion occurs when the nail is locked proximally and distally with the arm in internal rotation; this leads to decreased humeral retroversion and, consequently, external rotation.

    • Surgical neck nonunion occurs in cases of persistent distraction at the fracture site, and two-part fractures should be compressed prior to proximal locking.

    • With intramedullary nails and dedicated instrumentation, these two complications can be avoided by the following:

       

      • Using an external alignment guide

      • Backslap technique: consisting in retrograde hammering after distal locking, which impacts the surgical neck fracture site, preventing nonunion

 

POSTOPERATIVE CARE

 

Sling with abduction pillow that allows the proximal humerus to rest in neutral rotation and slight abduction (relax the rotator cuff and decrease tension on the GT) is worn for 3 to 4 weeks.

 

Gentle pendulum shoulder exercises as well as mobilization of the elbow, wrist, and fingers are started

immediately.

 

External rotation of the shoulder with the arm at side and internal rotation with the hand in the back by a physiotherapist are prohibited for 6 to 8 weeks postoperatively.

 

Active-assisted range-of-motion (ROM) exercises of the shoulder are allowed 4 to 6 weeks postoperatively. Swimming is encouraged.

 

COMPLICATIONS

Most early complications can be avoided by attention to surgical technique, the locking nail design, and proper measurement and orientation of the screws.

Early

Injury to axillary nerve Joint penetration Loss of reduction Infection

Late

Nonunion Posttraumatic arthrosis

Avascular necrosis of humeral head Prominent hardware

 

 

SUGGESTED READINGS

  1. Bigliani LU, Flatow EL, Pollock RG. Fractures of the proximal humerus. In: Rockwood CA, Green DP, Bucholz RW, et al, eds. Fractures in Adults. Philadelphia: Lippincott-Raven, 1996:1055-1107.

     

     

  2. Boileau P. Intramedullary nail for proximal humerus fractures: an old concept revisited. In: Shoulder Concepts 2010-Arthroscopy & Arthroplasty. Montpellier, France: Sauramps, 2010:201-223.

     

     

  3. Connor PM, Flatow EL. Complications of internal fixation of proximal humeral fractures. Instr Course Lect 1997;46:25-37.

     

     

  4. Darder A, Darder A Jr, Sanchis V, et al. Four-part displaced proximal humerus fractures: Operative treatment using Kirchner wires and a tension band. J Orthop Trauma 1993;7:497-505.

     

     

  5. Esser RD. Open reduction and fixation of three- and four part fractures of the proximal humerus. Clin Orthop Relat Res 1994;(299):244-251.

     

     

  6. Goldman RT, Koval KJ, Cuomo F, et al. Functional outcome after humeral head replacement for acute three- and four-part proximal humeral fractures. J Shoulder Elbow Surg 1995;4:81-86.

     

     

  7. Hawkins RJ, Switlyk P. Acute prosthetic replacement for severe fractures of the proximal humerus. Clin

    Orthop Relat Res 1993;(289): 156-160.

     

     

  8. Ko J, Yamamoto R. Surgical treatment of complex fracture of the proximal humerus. Clin Orthop Relat Res 1996;(327):225-237.

     

     

  9. Mouradian WH. Displaced proximal humeral fractures. Seven years' experience with a modified Zickel supracondylar device. Clin Orthop Relat Res 1986;(212):209-218.

     

     

  10. Nayak NK, Schickendantz MS, Regan WD, et al. Operative treatment of nonunion of surgical neck fractures of the humerus. Clin Orthop Relat Res 1995;(313):200-205.

     

     

  11. Neer CS II. Displaced proximal humeral fractures. I. Classification and evaluation. J Bone Joint Surg Am 1970;52(6):1077-1089.

     

     

  12. Neer CS II. Displaced proximal humeral fractures. II. Treatment of threeand four-part displacement. J Bone Joint Surg Am 1970;52(6):1090-1103.

     

     

  13. Norris TR. Fractures of the proximal humerus and dislocations of the shoulder. In: Browner BD, Jupiter JB, Levine AM, et al, eds. Skeletal Trauma: Fractures-Dislocations-Ligamentous Injuries. Philadelphia: WB Saunders, 1992:120-129.

     

     

  14. Riemer BL, D'Ambrosia RD, Kellam JF, et al. The anterior acromial approach for antegrade intramedullary nailing of the humeral diaphysis. Orthopaedics 1993;16:1219-1223.

     

     

  15. Robinson CM, Christie J. The two-part proximal humeral fracture: a review of operative treatment using two techniques. Injury 1993;24:123-125.

     

     

  16. Rush LV. Atlas of Rush Pin Technique: A System of Fracture Treatment. Meridian, MI: Bervion, 1955:166-167.

     

     

  17. Szyszkowitz R, Seggl W, Schleifer P, et al. Proximal humeral fractures: management techniques and expected results. Clin Orthop Relat Res 1993;(292):13-25.

     

     

  18. Weseley MS, Barenfeld PA, Eisenstein AL. Rush pin intramedullary fixation for fractures of the proximal humerus. J Trauma 1977;17: 29-37.

     

     

  19. Wheeler DL, Colville MR. Biomechanical comparison of intramedullary and percutaneous pin fixation for proximal humeral fracture fixation. J Orthop Trauma 1997;11:363-367.

     

     

  20. Yano S, Takamura S, Kobayashi I, et al. Use of the spiral pin for fracture of the humeral neck. J Orthop Science 1981;55:1607-1619.