Reverse Shoulder Arthroplasty in the Management of Proximal Humerus Fractures

Darren S. Drosdowech, M.D., FRCSC
George S. Athwal, M.D., FRCSC
Kenneth J. Faber, M.D., FRCSC
The HULC, St Joseph's Health Care
University of Western Ontario
London, Ontario

Reverse shoulder arthroplasty (RSA) has an established role in the treatment of conditions resulting in bone loss or soft tissue issues necessitating fixed-fulcrum mechanics. By extrapolation, comminuted osteopenic 3- and 4-part proximal humeral fractures in elderly patients may also be addressed using this philosophy, given the guarded outcomes using current standards such as ORIF or hemiarthroplasty (HHR). Additionally, many elderly patients have clinically undiagnosed rotator cuff disease prior to fracture that supports consideration of a reverse prosthesis to predictably restore function.

 

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Figure 1: AP radiograph of 3-part PHF in 80-year-old female

There is relatively little data supporting the use of RSA for acute proximal humeral fracture1-6. Of the few studies available, conclusions are limited due to study design. Gallinet1 et al. retrospectively compared 17 HHR's with 16 RSA's at 16.5 and 12.4 months respectively and demonstrated better mean abduction in the RSA group (91° for RSA vs 60° for HHR) but better external rotation in the HHR group (13.5° HHR, 9° RSA). Standard, non-fracture-specific implants were utilized in this study and tuberosities were routinely fixed in the HHR group whereas they were fixed in only one patient in the RSA group. The authors noted a "spectacularly good result" in the one RSA patient with tuberosity fixation showing not only improved elevation but substantially improved external rotation. In contrast, Bufquin2 examined 43 consecutive fractures treated with a RSA and noted satisfactory results comparable to that of HHR with a 53% rate of tuberosity displacement. It seems reasonable to conclude that standard principles of fracture arthroplasty (i.e. secure tuberosity fixation, postoperative protection to maximize union, possibly using fracture-specific implants), which have proven successful for HHR be followed when performing an RSA for acute fracture.

When performing a reverse arthroplasty for fracture, we recommend a deltopectoral incision be utilized; as it is extensile should more distal exposure be needed. The tuberosities are tagged with high-strength suture that allows for independent fixation to the prosthesis and the proximal humeral shaft. The prosthesis displaces the joint center-of-rotation inferomedially and the supraspinatus tendon must be resected to prevent overtensioning of the greater tuberosity fragment. Glenoid exposure is often uncomplicated due to the mobility of the fracture fragments, which allows the required visualization for correct inferior glenoid baseplate implantation. However, restoring adequate humeral length can be challenging due to proximal humeral bone loss and necessitates careful trial reduction to achieve adequate deltoid tension and subsequent joint stability. Intra-operative fluoroscopy can assist in ensuring proper tuberosity orientation and implant positioning.

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Figure 2: AP radiograph three months postop with non-fracture-specific RSA. Tuberosities demonstrated union to the proximal humeral diaphysis.

Following surgery, the shoulder is immobilized in neutral rotation with a sling to reduce the strain on the greater tuberosity fragment. Sequential radiographs are taken and once early signs of union at the tuberosity-humeral shaft junction are noted (three-six weeks) then assisted range of motion (ROM) exercises can begin. Usually unrestricted active ROM and graduated strengthening are started at six weeks postoperatively. Reverse shoulder arthroplasty is an effective surgical option in the treatment of 3- and 4-part proximal humeral fractures in the elderly. RSA may be the preferred fracture implant in the elderly patient with rotator cuff pathology or greater tuberosity comminution and osteopenia. We hypothesize that the constraint provided by the RSA may add a level of protection to the secured tuberosities, compared to a standard HHR, which may increase tuberosity union and improve patient outcomes. The advent of fracture-specific reverse stem designs may also help to improve outcomes although these devices are new to the orthopaedic marketplace and relatively unknown. Following standard principles of secure tuberosity fixation, postoperative immobilization until union is evident radiographically should be considered standard for these injuries. Improved longer-term clinical outcome studies are needed to better define the role of RSA in the management of acute fractures.

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Figures 3a and 3b: Postoperative forward elevation and external rotation three months post RSA for fracture.

References

 

  1. Gallinet D., Clappaz P., Garbuio P., Tropet Y., Obert L. Three or four parts complex proximal humerus fractures: Hemiarthroplasty versus reverse prosthesis: A comparative study of 40 cases. Orthopedics and Traumatology: Surgery and Research 2009:95, 48-55
  2. Bufquin T., Hersan A., Aubert L., Massin P. Reverse shoulder arthroplasty for the treatment of three and four part fracture of the proximal humerus in the elderly: a prospective review of 43 cases with a short-term follow-up. J Bone Joint Surg Br 2002;89:516-520
  3. Lenarz C., Shishani Y., McCrum C., Nowinski R., Edwards T., Gobezie R. Is Reverse Shoulder Arthroplasty Appropriate for the Treatment of Fractures in the Older Patient? Clin Orthop Relat Res 2011. 469:3324-3331
  4. Cazeneuve J.F., Cristofari D.J. Long term functional outcome following reverse shoulder arthroplasty in the elderly. Orthop Traumatol Surg Res. 2011 Oct;97(6):583-9
  5. Sirveaux F., Roche O., Mole D. Shoulder arthroplasty for acute proximal humerus fracture. Orthop Traumatol Surg Res 2010 Oct;96(6):683-94
  6. Young S., Segal B., Turner P., Poon P. Comparison of functional outcomes of reverse shoulder arthroplasty versus hemiarthroplasty in the primary treatment of acute proximal humerus fracture. ANZ Journal of Surgery 2010. 80(11): 789-793

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