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Fixation of a Proximal Humerus Fracture Using a Polyaxial Locking Plate and Endosteal Fibular Strut

Shah, Kalpit N. MD; Sobel, Andrew D. MD; Paxton, E. Scott MD

Author Information
Journal of Orthopaedic Trauma: August 2018 - Volume 32 - Issue - p S8-S9
doi: 10.1097/BOT.0000000000001209

Abstract

INTRODUCTION

Proximal humerus fractures (PHFs) are exceedingly common and represent the third most common fracture in the elderly.1 Most older patients sustaining these fractures are females who have had low-energy mechanisms such as a ground-level fall. However, there is a subset of younger male patients who have had higher energy mechanisms.2 Although there have been data supporting the role of nonoperative treatment in many individuals with PHFs,3 operative intervention may benefit the properly selected patient.3,4 Anatomic fixation of PHF in younger patients, as well as active, older patients, can lead to good outcomes, especially when anatomic reduction is obtained.5 The Supplemental Digital Content 1 (see Video, http://links.lww.com/JOT/A393) associated with this article goes through our preferred technique for fixation of these fractures.

Fixation strategies for PHFs have gone through an evolution over the past few decades. Closed reduction and percutaneous pinning,6 along with open reduction and internal fixation using non–locking plates, have generally fallen out of favor over locking plates and locking intramedullary nailings.7 The use of endosteal fibular strut grafts has been advocated in the setting of significant comminution or when structural support is needed to reduce the rate of postoperative complications.8

OPERATING ROOM SETUP

Patients are in the beach chair position with a fluoroscopic C-arm aligned posterior to the patient with the image intensifier posterior to the bed/shoulder and the x-ray tube positioned cranially over the shoulder girdle. Placing the intensifier posteriorly reduces radiation scatter and provides clearer images without impeding anterior access to the shoulder.

SURGICAL APPROACH

A standard deltopectoral approach is taken using the coracoid process as a guide proximally and the deltopectoral interval distally. Given that standard antiseptic preparations do not penetrate the dermal layers where the Propionibacterium acnes resides, vancomycin powder is placed along the subcutaneous border of the incision to reduce the bioburden at the beginning of the case. Subcutaneous tissues are divided and the cephalic vein is usually taken laterally while blunt dissection is performed through the interval. Subdeltoid adhesions and hypertrophic bursal tissues are cleared, followed by the placement of self-retaining retractors to facilitate exposure of the fracture.

REDUCTION AND FIXATION

The fracture fragments are first debrided of early callus. The edges of the main fracture line that is predictably found about 5 mm posterior to the bicipital groove is exposed to guide reduction. The humeral head is often impacted and malreduced in the coronal plane with additional deformity in the sagittal plane (apex-anterior). Kirschner wires placed from the proximal shaft into the head in the anterior-to-posterior trajectory can be used to hold the humeral head reduction.

Next, heavy, braided nonabsorbable sutures are placed into the rotator cuff insertions of the supraspinatus, infraspinatus, and teres minor to assist in fracture fragment manipulation. Bone grafting can assist with buttressing of the articular component of the fracture. Cancellous bone graft is prepared and impacted into the void under the humeral head. In the setting of significant comminution lateral to the articular surface, there is often a concern that reduction of the articular surface would not be maintained even with internal fixation. In such cases, a fibular strut can be added for extra structural stability because it provides a buttress effect behind the articular surface to prevent rotation of the surface into a valgus. We recommend that a fibular graft 4–5 cm in length be used. The graft should not extend distally past the expected site of the first diaphyseal screw in the fixation construct. After cutting the fibular graft to the appropriate length, a Kirschner wire is driven into the allograft to be used as a joystick and the fibula is inserted into the humeral canal. A wire is placed from anterior to posterior through the humeral shaft and into the graft to provide provisional fixation. A Cobb elevator can also be used to manipulate the fibular graft to aid in indirect reduction of the fracture fragments.

Before securing the plate, the greater tuberosity needs to be reduced to the head fragment. This is often performed with a combination of heavy, braided sutures tied from the posterior rotator cuff tendons to the anterior fragment and Kirschner wires placed from the greater tuberosity fragment into the humeral head. A plate is selected next and placed posterior to the bicipital groove and approximately 15 mm distal to the greater tuberosity to prevent impingement with shoulder flexion and abduction. If necessary, a small portion of the anterior insertion of the deltoid can be raised off the humeral shaft to allow for appropriate plate–bone contact.

A non–locking screw is placed first in the oblong shaft hole to allow for proximal–distal adjustments. Multiple locking screws are then placed proximally, starting with the calcar (“kickstand”) screws. Care should be taken to drill and then place the screws in a unicortical fashion to not violate the articular surface. Multiple screws are then placed in the humeral head in variable angulations to create the greatest spread of screws in all planes. Given the variability in patient anatomy (size and version), a polyaxial plate allows the surgeon to precisely place multiple kickstand screws, as well as to gain excellent purchase in the most solid proximal bone. The implant used in this video required the placement of locking caps to develop a fixed-angle construct. Distally, bicortical non–locking screws are used to ensure contact of the plate with the diaphysis.

For fractures with a lesser tuberosity fragment, often seen in valgus-impacted fractures with anterior displacement of the lesser tuberosity, a 3.5-mm non–locking screw with a washer is placed through the lesser tuberosity and into the fibula allograft, possibly extending through the posterior humeral cortex if it can be safely placed outside the articular surface. In addition, heavy, braided sutures can be placed through the subscapularis insertion and tied to the plate. Finally, heavy, braided nonabsorbable sutures are placed through the rotator cuff insertion and tied down to the plate.

REHABILITATION

The patient is placed into an abduction pillow sling for 6 weeks to take the tension of the greater tuberosity repair; however, passive range of motion exercises are immediately initiated. Full active and active assisted range of motion exercises begin after 4–6 weeks, depending on fracture morphology and healing, with initiation of strengthening between 10 and 12 weeks postoperatively if full range of motion has returned. Full recovery is seen between 6 and 12 months.

CONCLUSIONS

PHFs can be treated with a plate and polyaxial locking screws in an effective manner. The use of endosteal fibular strut grafts affords additional support in the setting of significant calcar comminution. This mode of fixation allows for early patient rehabilitation and excellent clinical results.

REFERENCES

1. Gupta AK, Harris JD, Erickson BJ, et al. Surgical management of complex proximal humerus fractures—a systematic review of 92 studies including 4500 patients. J Orthop Trauma. 2015;29:54–59.
2. Passaretti D, Candela V, Sessa P, et al. Epidemiology of proximal humeral fractures: a detailed survey of 711 patients in a metropolitan area. J Shoulder Elbow Surg. 2017;26:2117–2124.
3. Rangan A, Handoll H, Brealey S, et al. Surgical vs nonsurgical treatment of adults with displaced fractures of the proximal humerus. JAMA. 2015;313:1037.
4. Olerud P, Ahrengart L, Ponzer S, et al. Internal fixation versus nonoperative treatment of displaced 3-part proximal humeral fractures in elderly patients: a randomized controlled trial. J Shoulder Elbow Surg. 2011;20:747–755.
5. Schnetzke M, Bockmeyer J, Porschke F, et al. Quality of reduction influences outcome after locked-plate fixation of proximal humeral type-C fractures. J Bone Joint Surg Am. 2016;98:1777–1785.
6. Magovern B, Ramsey ML. Percutaneous fixation of proximal humerus fractures. Orthop Clin North Am. 2008;39:405–416, v.
7. Sobel AD, Shah KN, Paxton ES. Fixation of a proximal humerus fracture with an intramedullary nail. J Orthop Trauma. 2017;31:S47–S49.
8. Neviaser AS, Hettrich CM, Beamer BS, et al. Endosteal strut augment reduces complications associated with proximal humeral locking plates. Clin Orthop Relat Res. 2011;469:3300–3306.
Keywords:

proximal humerus fracture; polyaxial locking plate; endosteal fibular strut

Supplemental Digital Content

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