Minimum 2-year outcomes of reverse total shoulder arthroplasty for fracture: how does acute arthroplasty compare with salvage?

Reverse total shoulder arthroplasty for acute proximal humeral fracture has comparable 10-year outcomes to elective indications: results from the New Zealand Joint Registry

HYPOTHESIS AND BACKGROUND

Recently, the indication of reverse total shoulder arthroplasty (RTSA) has expanded beyond rotator cuff arthropathy to include treatment of complex acute proximal humeral fracture (PHF). Limited previous studies have compared the long-term clinical and functional outcomes of patients undergoing RTSA for PHF vs. elective indications for degenerative conditions. The purpose of this study was to compare implant survivorship, reasons for revision and functional outcomes in patients undergoing RTSA for acute PHF with those undergoing elective RTSA in a population-based cohort study.

METHODS

Prospectively collected data from the New Zealand Joint Registry from 1999 to 2021 and identified 6862 patients who underwent RTSA. Patients were categorized by preoperative indication, including PHF (10.8%), rotator cuff arthropathy (RCA) (44.5%), osteoarthritis (OA) (34.1%), rheumatoid arthritis (RA) (5.5%), and old traumatic sequelae (5.1%). Revision-free implant survival and functional outcomes (Oxford Shoulder Scores [OSSs] at the 6-month, 5-year, and 10-year follow-ups) were adjusted by age, sex, American Society of Anesthesiologists class, and surgeon experience and compared.

RESULTS

Revision-free implant survival at 10 years for RTSA for PHF was 97.3%, compared with 96.1%, 93.7%, 92.8%, and 91.3% for OA, RCA, RA and traumatic sequelae, respectively. When compared with RTSA for PHF, the adjusted risk of revision was significantly higher for traumatic sequelae (hazard ratio = 2.3, P = .023) but not for other elective indications. The most common reason for revision in the PHF group was dislocation or instability (42.9%), which was similar to the OA (47.6%) and traumatic sequelae (33.3%) groups. At 6 months post-surgery, OSSs were significantly lower for the PHF group compared with the RCA, OA, and RA groups (31.1 vs. 35.6, 37.7, and 36.5, respectively, P < .001), and similar to traumatic sequelae (31.7, P = .431). At 5 years, OSSs were only significantly lower for PHF compared with OA (37.4 vs. 41.0, P < .001) and there was no difference between the PHF and other groups. At 10 years, there were no significant differences between groups.

CONCLUSIONS

RTSA for PHF demonstrated reliable long-term survivorship and functional outcomes compared with elective indications. Despite lower functional outcomes in the early postoperative period for the PHF group, implant survivorship was similar in patients undergoing RTSA for the primary indication of acute PHF compared with RCA, OA, and RA and superior compared to the primary indication of traumatic sequelae.

Outcomes of Reverse Total Shoulder Arthroplasty for Proximal Humerus Fracture Versus Rotator Cuff Arthropathy

INTRODUCTION

Reverse total shoulder arthroplasty (RSA) is used to treat a variety of shoulder-related pathologies. This study compared medium-term clinical outcomes of less than 10-year follow-up in patients treated with RSA for proximal humerus fracture (PHF) versus rotator cuff arthropathy (RCA).

METHODS

This retrospective review was conducted at two tertiary care centers, in which self-reported clinical outcomes were assessed using four validated instruments, that is, American Shoulder and Elbow Society (ASES) score, Shoulder Pain and Disability Index (SPADI), visual analog scale (VAS), and shoulder subjective value (SSV). Statistical analyses were performed using linear or logistic regression with generalized estimating equations.

RESULTS

Of the 189 patients included in this study, 70 were treated for fracture and 119 for RCA. At a mean postoperative follow-up of 6.4 years, the means were 79.7 for ASES score, 20.8 for SPADI-Total, 0.8 for VAS, and 77.1 for SSV. After adjusting models for covariates, there was no significant difference in average SSV (P = 0.7), VAS (P = 0.7) or SPADI-Pain (P = 0.2) between PHF and RCA cohorts; however, the RCA cohort reported significantly better outcomes in ASES scores (P = 0.002), SPADI-Disability (P < 0.0001), and SPADI-Total (P = 0.0001).

DISCUSSION

Patients with RCA and PHF treated with RSA achieved similar medium-term outcomes in several domains, particularly postoperative pain levels; however, patients with PHF reported greater perceived disability. RSA is an effective pain-controlling procedure, but patients may have variable functional outcomes based on the indication for surgery.

The Relationship Between Frailty and Functional Outcomes, Range of Motion, and Reoperation After Reverse Total Shoulder Arthroplasty for Proximal Humerus Fracture

The objective of this study was to investigate whether frailty is associated with functional outcomes, motion, and reoperation at a minimum of 2 years after reverse total shoulder arthroplasty (rTSA) for proximal humerus fracture. We performed a retrospective study of 153 patients who underwent rTSA for proximal humerus fracture at two level 1 trauma centers from 2003 to 2018 with minimum 2-year follow-up. Frailty was assessed using the modified 5-item frailty index (mFI). The primary outcome variable was the American Shoulder and Elbow Surgeons (ASES) shoulder score at minimum 2-year follow-up. The secondary outcome variables were the Shoulder Pain and Disability Index (SPADI), the Shoulder Subjective Value (SSV), the 0 to 10 numeric rating scale (NRS) pain score, surgical complication, and reoperation. Bivariate comparisons were made between mFI and outcome variables. The mean age of the 153 patients was 70 years, and 76% were women. Forty patients (26%) had a mFI score of 0, 65 patients (42%) had a mFI score of 1, 40 patients (26%) had a mFI score of 2, and 8 patients (5%) had a mFI score of 3. Twenty-seven patients (18%) had complications, and 21 patients (14%) underwent reoperation. At minimum 2-year follow-up, mFI was not associated with ASES shoulder score, SPADI, SPADI pain or disability subscales, SSV, NRS pain score, active and passive shoulder forward flexion, abduction, and external rotation, complication, or reoperation. Provided they survive the initial physiologic insults of trauma and surgery, patients with higher mFI scores treated with rTSA for proximal humerus fracture can expect similar medium-term restoration of shoulder function. [Orthopedics. 2023;46(5):274-279.].

How common is nerve injury after reverse shoulder arthroplasty? A systematic review

BACKGROUND

Nerve injury following reverse shoulder arthroplasty (RSA) is a known risk factor with wide ranging incidences reported. This systematic review evaluates the overall incidence of nerve injury following primary and revision RSA and summarizes the characteristics of the nerve injuries reported in the current literature.

METHODS

A systematic review was performed using separate database searches (Pubmed, Embase, Web of Science, Cochrane) following the PRISMA guidelines. Search criteria included the title terms "reverse shoulder," "reverse total shoulder," "inverted shoulder," and "inverted total shoulder" with publication dates ranging from 01/01/2010 to 01/01/2022. Studies that reported neurological injuries and complications were included and evaluated for primary RSA, revision RSA, number of nerve injuries, and which nerves were affected.

RESULTS

After exclusion, our systematic review consisted of 188 articles. A total of 40,146 patients were included, with 65% female. The weighted mean age was 70.3 years. The weighted mean follow-up was 35.4 months. The rate of nerve injury after RSA was 1.3% (510 of 40,146 RSAs). The rate of injury was greater in revision RSA compared to primary RSA (2.4% vs. 1.3%). Nerve injury was most common in RSAs done for a primary diagnosis of acute proximal humerus fracture (4.0%), followed by cuff tear arthropathy (3.0%), DJD (2.6%), and inflammatory arthritis (1.7%). Massive rotator cuff tears and post-traumatic arthritis cases had the lowest nerve injury rates (1.0% and 1.4%, respectively). The axillary nerve was the most commonly reported nerve that was injured in both primary and revision RSA (0.6%), followed by the ulnar nerve (0.26%) and median nerve (0.23%). Brachial plexus injury was reported in 0.19% of overall RSA cases.

CONCLUSION

Based on current English literature, nerve injuries occur at a rate of 1.3% after primary RSA compared with 2.4% after revision RSA. The most common nerve injury was to the axillary nerve (0.64%), with the most common operative diagnosis associated with nerve injury after RSA being acute proximal humerus fracture (4.0%). Surgeons should carefully counsel patients prior to surgery regarding the risk of nerve injury.

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

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 35 o [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 27 o [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.