1 Principles top
If bone quality (minimal osteoporosis and limited comminution) is adequate, angular stable plate fixation offers potential for restoring function without arthroplasty. Be cautious, however, if reduction and fixation cannot be achieved satisfactorily.
Deltopectoral approaches generally provide the best access, but depending on fracture location and preoperative planning, anterolateral or transdeltoid can be considered.
Remember that in these fractures, a significant portion of the head is a part of the greater tuberosity fragment.
Anatomic reduction and elimination of varus deformity
Anatomic (step-less) reduction of the articular surface of the humeral head fragment is an essential part of this procedure.
Elimination of the varus deformity of the humeral head is also important.
Proper stabilization of the humeral head
In order to stabilize the humeral head appropriately, sufficient calcar support (screws) is necessary, to resist recurrent varus deformity.
Tension band sutures in addition to plate and screws
Sutures placed through the insertions of each rotator cuff tendon increase stability, and should be used as well as the plate and screws, particularly for more comminuted and/or osteoporotic fractures. With osteoporotic bone, the tendon insertion is often stronger than the bone itself, so that sutures placed through the insertional fibers of the tendon may hold better than screws or sutures placed through bone.
These additional sutures are typically the last step of fixation.
Angular stable versus standard plates
This procedure describes proximal humeral fracture fixation with an angular stable plate (A). Sometimes, these implants are not available. Standard plates provide an alternative option, for example the modified cloverleaf plate (B). Presently, the specific indications, advantages, and disadvantages of angular stable and standard plates are being clarified. There is some evidence that angular stable plate provide better outcomes. In addition to type and technique of fixation, the quality of reduction, the soft-tissue handling, and the characteristics of the injury and patient significantly influence the results. There is no evidence that the use of angular stable plates will overcome these other factors.
2 Reduction and preliminary fixation topenlarge
Place rotator cuff sutures
Subscapularis and supraspinatus tendon
Begin by inserting sutures into the subscapularis tendon (1) and the supraspinatus tendon (2). Place these sutures just superficial to the tendon’s bony insertions. These provide anchors for reduction, and temporary fixation of the greater and lesser tuberosities.
Next, place a suture into the infraspinatus tendon insertion (3). This can be demanding, and may be easier with traction on the previously placed sutures, or with properly placed retractors.
Variations depending on the approach chosen
Inserting sutures into the infraspinatus tendon is easier with a lateral approach. A) shows a deltopectoral approach and B) an anterolateral (transdeltoid) approach.
Use of stay sutures
Anterior traction on the supraspinatus tendon helps expose the greater tuberosity and infraspinatus tendon.
Insert a preliminary traction suture into the visible part of the posterior rotator cuff …
… and pull it anteriorly. This will expose the proper location for a suture in the infraspinatus tendon insertion. Then the initial traction suture is removed.
Pearl: larger needles
A stout sharp needle facilitates placing a suture through the tendon insertion.
Pearl: use of retractors
Use of blunt, curved Hohmann retractors underneath the deltoid muscle can be helpful to expose the humeral head.
Similarly, a so-called delta retractor may improve deltoid retraction.
Pitfall: use of forceps or clamps in osteoporotic bone
Grabbing bone fragments with a forceps or clamp will typically increase comminution of osteoporotic bone. This should be avoided by using sutures as “handles” for manipulation and reduction.
Reduction of the head split
Reduce the humeral head split using digital pressure, periosteal elevators, and/or partially threaded pin(s) in either head fragment.
Check the reduction by image intensification.
The sagittal head split fracture line is typically not visible since it is covered by the rotator cuff. Since a step-less reduction is crucial, a supraspinatus-splitting incision is recommended to see the fracture line.
Preliminarily fix the humeral head split
When anatomic, step-less reduction has been achieved, perform preliminary fixation with 2 or 3 K-wires. While lag screws may provide better fixation these may be in the way of the angular stable plate screws. Thus, K-wires, which can be easily changed, are preferable. If necessary, supplementary lag screws can be added for the humeral head fracture.
Reduce the lesser tuberosity
With the greater tuberosity properly reduced to the humeral head fragment, a defect remains into which the lesser tuberosity must be reduced. This can be performed by pulling on the stay sutures in the subscapularis tendon. If the lesser tuberosity is not mobile enough, reduction can be facilitated by the additional help of a periosteal elevator.
The horizontal suture between the infraspinatus and the subscapularis tendons closes the tuberosities underneath the humeral head. Confirm that the vertical fracture line is anatomical.
Reduction and preliminary fixation of the shaft
Reduce the shaft to the reduced proximal humerus and secure the reduction temporarily 2 or 3 K-wires. Make sure to place them from anterior, away from the foreseen plate position.
Pearl: osteoporotic bone
In osteoporotic bone, stability may be increased by accepting some medial impaction of the humeral head.
Confirm the overall reduction
After preliminary fixation check the reduction visually and by image intensification.
There should be no gap or step-off between the tuberosities. The inferior spike of the greater tuberosity should fit snugly against the shaft fragment.
Check the position of the humeral head in the axial/lateral view and be sure that there is no anteversion or excessive retroversion of the humeral head. This view might also reveal malpositioned tuberosities.
To avoid redisplacing a provisionally stabilized fracture, rotate the C-arm to obtain the axial view instead of moving the patient’s upper limb.
3 Plate fixation topenlarge
Attach plate to humeral shaft
Attach the plate to the humeral shaft with a bicortical small fragment 3.5 mm screw inserted through the elongated hole.
Pearl 1: fine tuning of plate position
If the first screw is inserted only loosely in the center of the elongated hole, fine-tuning of the plate position is still possible. With the plate in proper position, tighten this screw securely.
Correct plate position
The correct plate position is:
- about 5-8 mm distal to the top of the greater tuberosity
- aligned properly along the axis of the humeral shaft
- slightly posterior to the bicipital groove (2-4 mm)
Confirmation of correct plate position
The correct plate position can be checked by palpation of its relationship to the bony structures and also confirmed by image intensification.
To confirm a correct axial plate position insert a K-wire through the proximal hole of the insertion guide. The K-wire should rest on the top of the humeral head.
Pitfall 1: plate too close to the bicipital groove
The bicipital tendon and the ascending branch of the anterior humeral circumflex artery are at risk if the plate is positioned too close to the bicipital groove. (The illustration shows the plate in correct position, posterior to the bicipital groove).
Pitfall 2: plate too proximal
A plate positioned too proximal carries two risks:
- The plate can impinge the acromion
- The most proximal screws might penetrate or fail to securely engage the humeral head
Pearl 2: preliminary plate fixation with K-wires
For x-ray confirmation of plate position, one can fix the plate preliminarily to the bone with several 1.4 mm K-wires inserted through the small plate holes, before placing any screws.
Additionally, these K-wires help stabilize the fracture.
Pearl 3: insert K-wires through appropriate guiding sleeves.
Fix plate to the humeral head
Use an appropriate sleeve to drill holes for the humeral head screws. Do not drill through the subchondral bone and into the shoulder joint.
Avoiding intraarticular screw placement
Screws that penetrate the humeral head may significantly damage the glenoid cartilage. Primary penetration occurs when the screws are initially placed. Secondary penetration is the result of subsequent fracture collapse. Drilling into the joint increases the risk of screws becoming intraarticular.
Two drilling techniques help to avoid drilling into the joint.
Pearl 1: “Woodpecker”-drilling technique (as illustrated)
In the woodpecker-drilling technique, advance the drill bit only for a short distance, then pull the drill back before advancing again. Keep repeating this procedure until subchondral bone contact can be felt. Take great care to avoid penetration of the humeral head.
Pearl 2: Drilling near cortex only
Particular in osteoporotic bone, one can drill only through the near cortex. Push the depth gauge through the remaining bone until subchondral resistance is felt.
Determine screw length
The intact subchondral bone should be felt with a depth gauge or blunt pin to ensure that the screw stays within the humeral head. The integrity of the subchondral bone can be confirmed by palpation or the sound of the instrument tapping against it. Typically, choose a screw slightly shorter than the measured length.
Insert a locking-head screw through the screw sleeve into the humeral head. The sleeve aims the screw correctly. Particularly in osteoporotic bone, a screw may not follow the hole that has been drilled.
Number of screws and location
Place a sufficient number of screws (often 5) into the humeral head. The optimal number and location of screws has not been determined. Bone quality and fracture morphology should be considered. In osteoporotic bone a higher number of screws may be required.
It is strongly recommended to use “calcar screws” in all varus displaced fractures, especially, if there is medial comminution. Their purchase in the inferomedial humeral head adds mechanical stability.
Lesser tuberosity fixation
If the lesser tuberosity is involved, lag screw fixation might be considered. This technique may be superfluous when appropriate tension band sutures are placed through the rotator cuff insertions. Another option is one or more absorbable polymer pins.
If in doubt, once the sutures are secure, check the stability of the lesser tuberosity clinically by rotating the arm. If there is any micro movement visible or palpable consider additional fixation, which is typically placed after the rest of the fixation.
Insert additional screws into the humeral shaft
Insert one or two additional bicortical screws into the humeral shaft.
Any K-wires placed during the procedure may now be removed.
4 Supplementary rotator cuff tendon sutures topenlarge
Secure the tendons of the rotator cuff (subscapularis, supraspinatus, infraspinatus) with additional tension band sutures through the small holes in the plate.
5 Use of standard plates topenlarge
If no angular stable plate is available, a standard plate provides an alternative. The described procedure (reduction, preliminary fixation, and rotator cuff sutures) is essentially the same for standard plates, except for the screws. A good choice from the standard plates is the small fragment cloverleaf plate, with its tip cut off, and contoured as necessary. This plate allows multiple small fragment screws for the humeral head.
Be aware that angular stable implants provide better fixation, especially in osteoporotic bone. On the other hand, even angular stable plates are not a substitute for good surgical technique and judgment. Advances in fracture classification, understanding of the blood supply, use of rotator cuff tendon sutures, anatomical fracture reduction, and provisional fixation, represent improvements in care. When combined with optimal implants, these contributions offer the best chance of a good outcome.
6 Final check of osteosynthesis topenlarge
Using image intensification, carefully check for correct reduction and fixation (including proper implant position and length) at various arm positions. Ensure that screw tips are not intraarticular.
Also obtain an axial view.
In the beach chair position, the C-arm must be directed appropriately for orthogonal views. Position arm as necessary to confirm that reduction is satisfactory, fixation is stable, and no screw is in the joint.