Reverse Total Shoulder Arthroplasty Demonstrates Better Outcomes Than Angular Stable Plate in the Treatment of Three-part and Four-part Proximal Humerus Fractures in Patients Older Than 70 Years
Authors: Lanzetti Riccardo Maria , Gaj Edoardo , Berlinberg Elyse J. , Patel Harsh H. , Spoliti Marco 
Published: November 2022

Abstract

Background
Proximal humeral fractures are traditionally treated with open reduction and internal fixation (ORIF), but reverse total shoulder arthroplasty (RTSA) has emerged as an increasingly popular treatment option. Although ORIF with angular locking plates is a common treatment for proximal humerus fractures, prior reports suggest high failure and complication rates. Although RTSA has become an increasingly popular option for complex proximal humeral head fractures given its low complication rates, there are concerns it may lead to limited postoperative ROM. Thus, the optimal treatment for patients older than 70 years from a functional and radiographic perspective remains unclear.

Questions/purposes
(1) In patients older than 70 years with three-part and four-part proximal humerus fractures, does RTSA result in better functional outcome scores (Constant, American Shoulder and Elbow Surgeons [ASES], and DASH scores) than ORIF with a locking plate? (2) Does RTSA result in greater ROM than ORIF? (3) Does RTSA result in a lower risk of complications than ORIF? (4) In patients with either procedure, what are the rates of negative radiographic outcomes in those treated with ORIF (such as malunion, bone resorption, malalignment, or avascular necrosis) or those with RTSA (such as resorption, notching, and loosening)? (5) At a minimum of 2 years of follow-up, does ORIF result in a greater number of revision procedures than RTSA?

Methods
Between January 1, 2013, and June 30, 2018, we treated 235 patients for a proximal humeral fracture. We considered only patients without previous ipsilateral fracture or surgery, other fractures, or radial nerve injuries; age older than 70 years; and patients without neurologic disease or cognitive dysfunction as potentially eligible. Sixty-nine percent (162 patients) of the patients were eligible; a further 31% (73 patients) were excluded because 18% (13 of 73 patients) did not meet the inclusion criteria, 62% (45 patients) underwent nonoperative treatment, and 21% (15 patients) declined to participate. Patients were nonrandomly allocated to receive RTSA if they had supraspinatus Goutallier/Fuchs Grade 3 or 4 atrophy or ORIF if they had supraspinatus Goutallier/Fuchs Grade 1 or 2 atrophy. This left 81 patients who were treated with RTSA and another 81 patients who were treated with ORIF. Among the 81 patients treated with RTSA, 11% (nine patients) were lost to the minimum study follow-up of 2 years or had incomplete datasets, leaving 89% (72 patients) for analysis. Among the 81 patients treated with ORIF, 19% (15 patients) were lost before the minimal study follow-up of 2 years or had incomplete datasets, leaving 82% (66 patients) for analysis. The median follow-up for both groups was 53 months (range 24 to 72 months). The mean age was 76 ± 2.9 years in the RTSA group and 73 ± 2.9 years in the ORIF group. In the RTSA group, 27 patients had a three-part fracture and 45 patients had a four-part fracture. In the ORIF group, 24 patients had three-part fractures and 42 patients had four-part fractures (p = 0.48). Shoulder function was assessed using functional outcome questionnaires (ASES, DASH, and Constant) and active ROM measurements. A surgical complication was defined as any instance of dislocations, fractures, adhesive capsulitis, nerve injuries, or surgical site infections. Radiographic outcomes after ORIF (malunion, tuberosity resorption, or avascular necrosis) and RTSA (notching and osteolysis) were assessed. In calculating the revision rate, we considered unplanned revision procedures only.

Results
Compared with patients treated with ORIF, patients treated with RTSA had superior improvements in Constant (85.0 ± 7.0 versus 53.0 ± 5.0; mean difference 32 [95% CI 30 to 34]; p < 0.01), ASES (46.3 ± 3.7 versus 30.0 ± 3.5; mean difference 16 [95% CI 15 to 18]; p < 0.01), and DASH scores (40.5 ± 4.2 versus 30.5 ± 2.6; mean difference 10 [95% CI 9 to 11]; p < 0.01). The mean elevation was 135° ± 7° for patients with RTSA and 100° ± 6° for patients with ORIF (mean difference 35o [95% CI 33 to 37]; p < 0.01). The mean abduction was 131° ± 7° for patients with RTSA and 104° ± 6° for those with ORIF (mean difference 27o [95% CI 25° to 29°]; p < 0.01). The mean external rotation was 85° ± 5° for patients with RTSA and 64° ± 5° for those with ORIF (mean difference 21° [95% CI 19° to 23°]; p < 0.01). The mean internal rotation was 45° ± 6° for patients with RTSA and 40° ± 6° for those with ORIF (mean difference 5° [95% CI 3° to 7°]; p < 0.01). The risk of complications was not different between patients with ORIF and those with RTSA (5% [three of 66] versus 1% [one of 72]; relative risk 3.3 [95% CI 0.3 to 30.7]; p = 0.30). Among patients with ORIF, 8% had varus malunions (five of 66), 6% had resorption of the greater tuberosity (four of 66), and 2% had avascular necrosis of the humeral head (one of 66). In the RTSA group, 24% (17 of 72 patients) demonstrated reabsorption of periprosthetic bone and 79% of patients (57 of 72) exhibited no notching. The risk of revision was not different between the RTSA and ORIF groups (0% [0 of 72] versus 9% [six of 66]; relative risk 0.07 [95% CI 0.0 to 1.2]; p = 0.07).

Conclusion
In patients older than 70 years with three-part and four-part proximal humerus fractures, primary RTSA resulted in better patient-reported outcome scores and better ROM than ORIF with an angular stable locking plate. Our findings might help surgeons decide between internal fixation and arthroplasty to surgically treat these injuries in older patients. Although RTSA seems to be a preferable treatment modality in view of these findings, longer follow-up is required to evaluate its longevity compared with ORIF with an angular locking plate. Dissimilar to ORIF, which is generally stable once healed, arthroplasties are at a continued risk for loosening and infection even after healing is complete.

Level of Evidence
Level II, therapeutic study.