What Is the Best Treatment for Complex Proximal Humerus Fractures? What Are the Main Determinants of Outcome after Arthroplasty?

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Chapter 20 What Is the Best Treatment for Complex Proximal Humerus Fractures? What Are the Main Determinants of Outcome after Arthroplasty?

JASON L. HURD, MD, JOSEPH D. ZUCKERMAN, MD

Proximal humerus fractures account for 4% to 5% of all fractures.¹ The majority of proximal humerus fractures (approximately 80%) are minimally displaced and can be treated with a sling and early mobilization.² Two-part fractures are most often treated with some form of osteosynthesis. Frequently, attempts to preserve the proximal humerus are also made in young, active patients with good bone quality who have three-part and valgus-impacted four-part fractures (level V). Osteosynthesis is usually considered preferable to hemiarthroplasty in young patients (level V) because of concerns about glenoid wear and implant longevity.³^–⁵

Certain complex proximal humerus fractures, however, are either not amenable to fixation or are at significant risk for humeral head osteonecrosis, making osteosynthesis a less desirable option. These include widely displaced four-part fractures and fracture dislocations, head-splitting fractures with greater than 40% articular surface involvement, anatomic neck fractures, and selected three-part fractures in patients with osteopenia and nondisplaced comminution that precludes secure internal fixation.⁶ In these cases where the risk for fixation failure is high, humeral head replacement is generally accepted as the best option. Support for this philosophy comes from the fact that primary hemiarthroplasties are technically easier and have been consistently shown in retrospective comparative series to have better outcomes than secondary hemiarthroplasties performed for failed internal fixation or nonoperative treatment.⁷^–¹¹

The literature on prosthetic treatment of complex proximal humerus fractures is sparse. Only three level I or II studies currently exist: one compares hemiarthroplasty with nonoperative treatment,¹² whereas the other two compare hemiarthroplasty with tension band wiring.^13,¹⁴

In 1984, Stableforth ¹² conducted a prospective, randomized, nonblinded comparison of uncemented hemiarthroplasty and nonoperative treatment. His study included 32 patients with an average age of 67 who had four-part proximal humerus fractures. The author found a significant reduction in pain, improved range of motion and strength, and greater ability to perform activities of daily living in patients treated with hemiarthroplasty. Criticisms of this limited study include its variable and relatively short follow-up period, unclear method of randomization, and poorly defined outcome measurements.¹⁵

In 1997, Hoellen and colleagues ¹³ compared hemiarthroplasty with open reduction and tension band wiring in a randomized, controlled trial of 30 patients, older than 65 years, with 4-part fractures. One-year follow-up was available for only 18 of the 30 patients. Results in the two groups were comparable with respect to pain, function, and ability to perform activities of daily living. The most significant difference between the two groups was that none of the patients in the arthroplasty group required reoperation, were five patients in the fixation group required further surgery for wire displacement (four patients) or failed fixation (one patient).

Two years after the study by Hoellen and colleagues,¹³ Holbein and coworkers¹⁴ published a follow-up report. This subsequent study included 39 patients with both 3- and 4-part fractures with up to 2-year follow-up. One-year data were available for 31 patients with 2-year follow-up for 24 patients. The results of this study were similar to those that Hoellen and colleagues¹³ reported. The authors found no significant difference in patients with three- or four-part fractures treated with either tension band wiring or arthroplasty. At 2-year follow-up, however, nine patients in the fixation group required further surgery compared with none in the hemiarthroplasty group. It is difficult to make any sound conclusions from these studies because of the short follow-up period and significant dropout rate. The generalizability of these findings to younger patients is also unclear.

In 2003, Handoll and coworkers ¹⁵ conducted a Cochrane review on the treatment of proximal humerus fractures in adults. Based on their analysis, they were unable to provide any treatment recommendation. Both Bondi and coauthors ¹⁶ and Bhandari and investigators,¹⁷ after systematic evidence-based reviews on proximal humerus fractures, also found insufficient evidence from randomized trials to determine optimal treatment. They conclude that until valid evidence exists, the management of proximal humerus fractures will be based on surgeon preference, ability, and experience. Although evidence-based support for arthroplasty in the treatment of complex proximal humerus fractures is lacking, some evidence exists that arthroplasty can optimize patient outcomes once the decision to treat has been made.

RESULTS AFTER HUMERAL HEAD REPLACEMENT

Reliable pain relief, patient satisfaction, and reasonable implant longevity have been consistently demonstrated in multiple retrospective reviews of patients who underwent hemiarthroplasty for complex proximal humerus fractures. Good-to-excellent pain relief has been reported in 73% to 97% of patients; overall, more than 80% of patients expressed satisfaction with their treatment, and prosthesis survival at 10 years ranges from 83% to 94%.¹⁸

Functional outcomes, however, have been much more unpredictable. Even within individual studies, outcomes vary widely from patient to patient. Less desirable functional outcomes are most often because of limited shoulder motion, decreased muscle power, and inability to perform activities of daily living. The challenge for surgeons is to identify me-thods of maximizing outcomes through meticulous patient selection, optimal surgical techniques, and appropriate postoperative treatment. With this in mind, several authors have explored the preoperative, surgical, and postoperative factors that appear to influence outcome.

PREOPERATIVE FACTORS

Robinson and investigators ¹⁹ performed a level II observational cohort study of 163 patients with complex humerus fractures treated with hemiarthroplasty. Of the 163 patients, 25 died or were lost to follow-up within the first postoperative year. The remaining 138 patients with an average age of 68.5 years were evaluated with Constant scores. Using a univariate linear regression model, the authors assessed the factors immediately after injury and at 6 weeks after surgery; these factors were predictive of the Constant score at 1 year.

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