Commentary & Perspective

Commentary & Perspective on
"Primary Hemiarthroplasty for Treatment of Proximal Humeral Fractures"
by C. Michael Robinson, BMedSci, FRCS Ed(Orth), et al.

Commentary & Perspective by
Robert H. Cofield, MD*,
Department of Orthopedic Surgery, Mayo Clinic, Rochester MN

The authors and the surgeons who participated in this study are to be congratulated for their study design, similar to the approach used in a registry, that involved consistent operative treatment and long-term follow-up of patients with complex proximal humeral fractures. Although the fractures were treated over a thirteen-year period, from 1988 through 2000, the treatment regimen was consistent with contemporary standards. The selection of patients seems rigorous, yet straightforward, excluding those who were not medically fit, who were uncooperative or had dementia, and, importantly, those who had had poor shoulder function before the injury. The surgery was performed by only eight surgeons with use of only two types of implants. All implants were cemented, and the methods of tuberosity repair incorporated wires or heavy sutures. The postoperative treatment of these injuries may have been too aggressive, which I will discuss later.

One measure of the authors' selectivity in choosing their patient cohort is that only 163 of 3463 proximal humeral fractures were treated with primary shoulder hemiarthroplasty. Of these generally older patients, (average age, sixty-nine years), 138 were available for follow-up at one year or more after surgery. The inclusion criteria are well defined as are the indications for surgery. I think that the readers can have great confidence in this component of the study.

Results were assessed in two ways. One was the prosthetic survival rate, which was high (96.9% at one year); only eight revisions were necessary for various reasons of which none was predominant. The second component of measuring results was a rating system using the Constant score. The individual components of the Constant score are presented in a summary fashion, in a short paragraph in the Results section of the article. This reader's preference, perhaps like a number of others', is to see the actual data displayed more fully to gain a greater sense of the outcome of surgery. For example, how many patients achieved satisfactory pain relief? How many did not? How many had excellent function? How many did not? How many had an ample active range of motion? How many did not?

The radiographic findings and their correlation with outcome is important. Difficulties with tuberosity healing and subluxation of the prosthesis are highlighted, which is appropriate, for the basic question that might arise with this complex fracture is whether proximal humeral fractures treated with primary shoulder arthroplasty heal. With a substantial change in tuberosity position in fifty-three shoulders (forty-three had 10 to 20 mm of displacement and ten had greater than 20 mm of displacement of one or both tuberosities) and subluxation of the prosthesis in thirty-seven shoulders, the implication is that there were a large number of patients who did not achieve satisfactory healing of these fractures with this treatment^1-3. Again, it would be this reader's desire to see a clear display of the results data for patients who had healing of their fractured tuberosities with maintenance of the prosthesis in good position and those who did not. Probably, these outcomes can be determined mathematically with use of the multiple linear regression model, but display of the actual data would be direct and helpful. In fact, fracture healing with minimal prosthetic displacement may be the predominant reason for an improved surgical outcome. If so, a question arises about modification of the postoperative care for these patients. The authors reported that the patients wore a shoulder immobilizer sling for two to three weeks postoperatively and began an active-assisted range-of-motion exercise program at two weeks postoperatively. Clearly, this treatment timetable does not provide enough time for tuberosity healing to occur. Perhaps in the future, these surgeons (learning from their experience) will change the postoperative regimen to include more prolonged use of a sling or other support until tuberosity healing—six to eight weeks—and delay active range-of-motion exercises for at least this period of time. Would this change in regimen lead to more consistent healing of the tuberosities and avoid subluxation of the prosthesis? Although, to my knowledge, this has not been established, my suspicion is that it might well do so.

I believe that we can all learn a great deal from this study. Careful patient selection, on the basis of both patient characteristics and injury pattern, is necessary. A consistently well-performed surgical procedure must be followed by appropriate postoperative rehabilitation involving the use of external shoulder support. A rigorous postoperative follow-up assessment can lead to modifications in the rehabilitation program.

Multiple factors can influence the results of this surgery. The authors found that age, tobacco use, alcohol consumption, and persistent neurologic deficits had a significant association with the functional outcome as assessed with use of the modified Constant score at one year (p is less than 0.05). They also found that maintenance of the desired position of the prosthesis, quite likely associated with the tuberosities healing in good position, is important in predicting outcomes in patients and also in determining modifications in the postoperative treatment that will lead to improved outcomes. In addition, of course, as many complications as possible should be avoided.

This in-depth study clarifies the central issues surrounding the use of hemiarthroplasty for the treatment of proximal humeral fractures. Robinson et al. have provided information that will help us to improve the outcome of primary shoulder hemiarthroplasty for the treatment of proximal humeral fractures.

*The author did not receive grants or outside funding in support of his research or preparation of this manuscript. He did not receive payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, educational institution, or other charitable or nonprofit organization with which the author is affiliated or associated.

References

1. Antuna SA, Sperling JW, Sanchez-Sotelo J, Cofield RH. Shoulder arthroplasty for proximal humeral nonunions. J Shoulder Elbow Surg. 2002;11:114-21.
2. Antuna, SA, Sperling JW, Sanchez-Sotelo J, Cofield RH. Shoulder arthroplasty for proximal humeral malunions: long-term results. J Shoulder Elbow Surg. 2002;11:122-9.
3. Boileau P, Krishnan SG, Tinsi L, Walch G, Coste JS, Mole D. Tuberosity malposition and migration: reasons for poor outcomes after hemiarthroplasty for displaced fractures of the proximal humerus. J Shoulder Elbow Surg. 2002;11:401-12.