Reverse shoulder arthroplasty for proximal humerus fractures and reverse shoulder arthroplasty for elective indications should have separate Current Procedural Terminology (CPT) codes

Abstract

Background:

Reverse shoulder arthroplasty (RSA) for fracture currently shares a single Current Procedural Terminology (CPT) code with RSA for arthropathy despite potential differences in patient factors, procedural demands, postoperative care and needs, and overall hospital systems’ resource utilization. We hypothesize that patients indicated for RSA for fracture will have greater medical complexity, require longer operative duration, have higher complication rates, demonstrate inferior functional outcomes, and require greater health care cost expenditures compared to a cohort undergoing RSA for rotator cuff arthropathy.

Methods:

A total of 383 RSAs were retrospectively reviewed from January 2011 to December 2020. Demographics, comorbidities, operative time, financial charge and cost data, length of stay (LOS), discharge disposition, and all-cause revisions were assessed. Visual analog scale (VAS) pain score and active range of motion (AROM) were evaluated at 2, 6, and 12 months postoperatively.

Results:

After exclusions, 197 total RSAs were included, with 28 for fracture and 169 for arthropathy indications. RSA operative time was longer for fractures with an average of 143.2 ± 33.7 minutes compared with 108.2 ± 33.9 minutes for arthropathy (P = .001). Average cost per patient for RSA for proximal humerus fracture was $2489 greater than the cost for RSA for elective indications; however, no statistically significant difference was noted between average costs (P =.126). LOS was longer for RSA for fracture compared to arthropathy, with a mean of 4.0 ± 3.6 days vs. 1.8 ± 2.3 days (P = .004). The fracture group was 3.6 times more likely to be discharged to a skilled nursing facility or inpatient rehabilitation (32% vs. 9%, P = .002). Early and late all-cause revisions were similar between groups. Differences in postoperative AROM for fracture vs. arthropathy were significant for active forward flexion at 2 months (95.5° ± 36.7° vs. 117.0° ± 32.3°, P = .020) and 6 months (110.9° ± 35.2° vs. 129.2° ± 28.3°, P = .020) as well as active adducted external rotation at 6 months (20.0° ± 20.9° vs. 33.1° ± 12.3°, P = .007) and at 12 months (23.3° ± 18.1° vs. 34.5° ± 13.8°, P =.012). No difference in VAS pain scores were noted between fracture and arthropathy groups at any time point.

Discussion:

RSA for fractures vs. arthropathy have substantial differences in patient characteristics, surgical complexity, and hospital resource utilization. This is of importance given the currently available CPT code does not differentiate indications for RSA, especially if intending to accurately document the surgical care delivered.

Level of evidence:

Level III; Retrospective Cohort Comparison; Prognosis Study

Proximal humerus fractures affect 5% of patients aged ≥65 years and can be challenging to treat. Additional considerations are necessary and include functional demands of the patient, associated comorbidities, and fracture-specific factors.⁹ Approximately 85% of cases are successfully managed nonoperatively. In patients requiring operative intervention, open reduction internal fixation (ORIF) is one surgical treatment option and aims to restore shoulder anatomy. Complications associated with ORIF include hardware failure, nonunion, malunion, and avascular necrosis.^1,6,8 Historically, comminuted fractures were treated with hemiarthroplasty as the preferred treatment option over ORIF. However, shoulder hemiarthroplasty is also associated with complications including tuberosity nonunion or malunion and limited ability to compensate for coexisting rotator cuff pathology, often resulting in poor patient outcomes.¹⁰

Reverse shoulder arthroplasty (RSA), originally developed for the treatment of massive rotator cuff tears and rotator cuff arthropathy, has grown in popularity for proximal humerus fractures. RSA has proven an effective surgical alternative, as patients with proximal humerus fractures treated with ORIF or hemiarthroplasty historically had high failure rates.¹⁵ Still, there are important considerations in RSA for proximal humerus fracture compared with rotator cuff tear arthropathy. Notably, there are higher complication rates, longer operative times, increased postoperative length of stay (LOS), and adverse events in patients undergoing RSA for proximal humerus fractures, imposing greater resource utilization on the surgeon and health care system.^5,12,15

Despite these differences, total shoulder arthroplasty, regardless of indication, is listed as a single Current Procedural Terminology (CPT) code. The American Medical Association (AMA) states that CPT codes are tools to uniformly inform and communicate on performed medical services and procedures. Specifically, the AMA highlights the importance of accuracy, transparency, and efficiency in this process. As it currently stands, the single CPT code for total shoulder arthroplasty may not meet the goal intended by the AMA. Many other subspecialities have similarly challenged available CPT codes in their own realms citing comparable discrepancies and importance of updating the current universally available coding system.^2,16,18–20

We aim to expand on currently available data highlighting differences between patients undergoing elective RSA for rotator cuff arthropathy vs. those undergoing RSA for proximal humerus fractures. We hypothesize that patients with proximal humerus fractures will have longer operative times, higher complication rates, inferior clinical functional outcomes, and higher health care cost expenditures compared with a cohort undergoing elective RSA for rotator cuff arthropathy.

Materials and methods

This is a retrospective cohort study of perioperative resource utilization and postoperative outcomes following RSA for acute proximal humerus fractures vs. RSA for chronic arthropathy disorders. After obtaining institutional review board (IRB) approval, 383 RSAs, including 71 for proximal humerus fractures and 312 for arthropathy etiologies, performed from January 2011 to December 2020 by 3 shoulder and elbow–trained surgeons were queried. Inclusion criteria included all patients with acute proximal humerus fractures or rotator cuff arthropathy, glenohumeral osteoarthritis, irreparable rotator cuff tears, inflammatory arthritis, and chronic shoulder instability or dislocation who underwent primary RSA with CPT code 23472. Exclusions included patients with prior ORIF, malunion or nonunion, pathologic lesion or fractures, those with <1-year follow-up, and anyone with missing data (Table I).

Table I.

Fracture vs. arthropathy group diagnosis

Indication	Fracture, n (%) (n = 28)	Arthropathy, n (%) (n = 169)
Proximal humerus fracture	28 (100)	0 (0)
Glenohumeral osteoarthritis	0 (0)	34 (20)
Rotator cuff arthropathy	0 (0)	121 (72)
Irreparable rotator cuff tear	0 (0)	10 (6)
Inflammatory arthritis	0 (0)	4 (2)

Patient demographics including age, body mass index, Charlson Comorbidity Index, operative time, LOS, early and late all-cause revision rates, and discharge disposition were collected. The primary outcome was resource utilization as estimated by cost and charges. Secondary postoperative outcomes including range of motion and pain, measured as active forward flexion in the plane of the scapula (aFF), active adducted external rotation (aER), and visual analog scale (VAS) score. These outcomes were recorded at 2, 6, and 12 months, postoperatively. Range of motion was measured and recorded in the clinic using visual assessment by senior surgeons only. Frequencies and percentages are reported for categorical variables and means and standard deviations are reported for continuous variables. All-cause revision rates were classified into early or within 90 days of the index surgery, and late being from 91 days to the end of study follow-up period of 2 years. Average cost of treatment and charges were calculated from date of admission to the 90th postoperative day for each patient in the study. Cost was defined as the expense incurred to deliver health care services to patients, whereas charges were defined as the amount asked by a provider for a health care good or service that would appear on a medical bill.¹⁴ These data were extracted directly by the institution financial department and statistically analyzed with sample t tests and χ² tests. Correction for multiple comparisons were deemed not necessary based on the works by Rothman and Saville, and instead, individual P values are provided for each comparison.^17,18

Results

Demographics and comorbidities

Following exclusions, our study cohort included 197 RSAs, 28 for fracture and 169 for other chronic arthropathy etiologies. Mean follow-up overall was 24 months. The fracture group had 24.2 months (range = 12–46 months) of follow-up, and the other group had 23.9 months (range = 12–84 months) of follow-up. Most of the patients were female (65%), White (84%), and of non-Hispanic origin (91%) with a mean age and body mass index of 69.6 ± 9.6 years and 31.1 ± 7.0, respectively. No statistically significant differences were observed in age, sex, race, ethnicity, and body mass index between groups (Table II).

Table II.

Fracture vs. arthropathy group differences by demographics

Characteristic	Fracture (n = 28)	Arthropathy (n = 169)	P value
Age, yr, mean (SD)	67.6 (12.2)	70.0 (9.1)	.334
Sex, n (%)
Female	21 (75)	107 (63)	.477
Male	7 (25)	62 (37)	.333
Race, n (%)
Black	0 (0)	19 (11)	.076
White	27 (96)	139 (82)	.449
Other	1 (4)	11 (7)	.560
Ethnicity, n (%)
Hispanic origin	2 (7)	16 (9)	.706
Non-Hispanic origin	26 (93)	153 (91)	.905
BMI, mean (SD)	30.7 (8.9)	31.2 (6.7)	.804

SD, standard deviation; BMI, body mass index.

When comparing past medical history, patients in the fracture group were more likely to have a clinical history of mild liver disease (P =.041), whereas patients in the chronic arthropathy group were more likely to have a prior history of myocardial infarction (P = .049) (Table III). There were no differences noted between groups regarding insurance type or American Society of Anesthesiologists physical status classification (ASA) score between fracture and chronic arthropathy diagnosis groups (Tables IV and V).

Table III.

Fracture vs. arthropathy group differences by individual comorbidities

Comorbidity	Fracture, n (%) (n=28)	Arthropathy, n (%) (n = 169)	P value
AIDS	0 (0)	0 (0)	—
Malignancy	3 (11)	23 (14)	.734
Cerebrovascular	8 (29)	39 (23)	.528
COPD	11 (39)	50 (30)	.343
CHF	4 (14)	33 (20)	.594
Dementia	1 (4)	6 (4)	.973
Diabetes with complications	4 (14)	24 (14)	.945
Diabetes without complications	5 (18)	51 (30)	.287
Hemiplegia	0 (0)	7 (4)	.289
Metastatic	0 (0)	1 (1)	.686
Mild liver	10 (36)	30 (18)	.041*
Moderate liver	1 (4)	2 (1)	.328
MI	0 (0)	24 (14)	.049*
Peptic ulcer	2 (7)	11 (7)	.879
PVD	7 (25)	34 (20)	.549
CKD	5 (18)	28 (17)	.827
Rheumatic	1 (4)	23 (14)	.170

COPD, chronic obstructive pulmonary disease; CHF, congestive heart failure; MI, myocardial infarction; PVD, peripheral vascular disease; CKD, chronic kidney disease.

^*Statistically significant difference (P < .05).

Table IV.

Fracture vs. arthropathy group differences by insurance

Insurance	Fracture, n(%) (n=28)	Arthropathy, n (%) (n = 169)	P value
Medicare	20 (71)	124 (73)	.911
Medicaid	4 (14)	14 (8)	.330
Private	4 (14)	19 (11)	.662
Worker’s compensation	0 (0)	12 (7)	.159

Table V.

Fracture vs. arthropathy group differences by ASA rating

ASA class	Fracture, n(%) (n=28)	Arthropathy, n(%) (n = 169)	P value
1	0 (0)	1 (1)	.684
2	6 (21)	39 (23)	.866
3	19 (68)	122 (72)	.801
4	3 (11)	7 (4)	.153

ASA class, American Society of Anesthesiologists physical status classification.

Resource utilization and costs

The average RSA operative time was longer for fracture at 143.2 ± 33.7 minutes compared with other chronic arthropathy diagnoses at 108.2 ± 33.9 minutes (P < .01). LOS for patients who underwent RSA for fracture was a mean 4.0 ± 3.6 days vs. 1.8 ± 2.3 days (P <.01). Patients in the fracture group were less likely to be discharged home or to a home health service (68% vs. 91%, P > .05) and 3.6 times more likely to be discharged to a skilled nursing facility or an inpatient rehabilitation facility (32% vs. 9%, P < .01). The data on resource utilization is summarized in Table VI. The average charge per patient for RSA for proximal humerus fracture was $19,630 higher than for elective RSA for any chronic arthropathy diagnoses (P = .0002). The average cost per patient for RSA for proximal humerus fracture was $2489 greater than the cost for RSA for elective indications; however, no statistically significant difference was noted between average costs (P = .126).

Table VI.

Fracture vs. arthropathy group differences by length of stay, operative time, and discharge location

Variable	Fracture (n = 28)	Arthropathy (n = 169)	P value
LOS, d, mean (SD)	4.0 (3.6)	1.8 (2.3)	.004
Operative time, min, mean (SD)	143.2 (33.7)	108.2 (33.9)	.001*
Discharge location, n (%)
Home or home health service	19 (68)	153 (91)	.234
Skilled nursing facility or inpatient rehabilitation facility	9 (32)	16 (9)	.002*

SD, standard deviation; LOS, length of stay.

^*Statistically significant difference (P < .05).

Revisions

Early revision rates were similar in the fracture group compared with the arthropathy group (4% vs. 3%, P =.87). The global revision rate within 2 years postoperatively was additionally similar in the fracture group compared with the arthropathy group (7% vs. 6%, P = .81) (Table VII).

Table VII.

Fracture vs. arthropathy group differences by revisions

Revisions	Fracture, n (%) (n = 28)	Arthropathy, n (%) (n = 169)	P value
Early (within 90 d)	1 (4)	5 (3)	.87
Global (up to 24 mo)	2 (7)	10 (6)	.81

Postoperative outcomes

Differences in patients’ postoperative range of motion were significant for aFF at 2 months (95.5° ± 36.7° vs. 117.0° ± 32.3°, P =.020), aFF at 6 months (110.9° ± 35.2° vs. 129.2° ± 28.3°, P = .020), aER at 6 months (20.0° ± 20.9° vs. 33.1° ± 12.3°, P =.007), and aER at 12 months (23.3° ± 18.1° vs. 34.5° ± 13.8°, P = .012) (Table VIII). VAS between groups (fracture vs. chronic arthropathy conditions) did not differ at any time point: 2 months (3.1 ± 2.9 vs. 2.3 ± 2.8, P = .19), 6 months (2 ± 2.7 vs. 1.7 ± 2.8, P = .60), or 12 months (1.7 ± 2.5 vs. 1.7 ± 2.8, P = .93) (Table VIII).

Table VIII.

Fracture vs. arthropathy group postoperative active range of motion and pain (VAS) after 2 months, 6 months, and 12 months

Variable	Fracture, degrees, mean (SD) (n = 28)	Arthropathy, degrees, mean (SD) (n = 169)	P value
2 mo
aFF	95.5 (36.7)	117.0 (32.3)	.020*
aER	22.0 (22.9)	27.6 (12.8)	.269
VAS	3.1 (2.3)	2.3 (2.8)	.192
6 mo
aFF	110.9 (35.2)	129.2 (28.3)	.020*
aER	20.0 (20.9)	33.1 (12.3)	.007*
VAS	2 (2.7)	1.7 (2.8)	.600
12 mo
aFF	123.5 (31.6)	136.6 (28.5)	.057
aER	23.3 (18.1)	34.5 (13.8)	.012*
VAS	1.7 (2.5)	1.7 (2.8)	.935

aFF, active forward flexion; aER, adducted external rotation; VAS, visual analog scale; SD, standard deviation.

^*Statistically significant difference (P < .05).

Discussion

Our study highlights important differences between patients undergoing RSA for fracture vs. RSA for arthropathy, including greater hospital resource utilization, higher hospital charges, increased operating room time, increased LOS, and greater propensity for disposition to rehabilitation or skilled nursing facility. Using hip arthroplasty in the setting of acute hip fractures vs. elective indications as an example, a distinct CPT code exists for hip hemiarthroplasty for fracture vs. other patients undergoing this procedure with an elective indication. The premise behind the different CPT code was supported by the likes of Schroer et al¹⁷ who noted patients undergoing hip arthroplasty for fracture had a greater age, LOS, and cost of care in the 90-day global period.^3,21,22

Since 1966, the AMA has used CPT codes to allow for a common language to capture medical services and procedures, aiming for an efficient methodology while also maintaining accurate representation of the medical care provided with full transparency.¹¹ Currently, only a single CPT code exists for shoulder arthroplasty, regardless of indication, despite the significant differences that may exist in not only the patient-specific factors but also the perioperative resource utilization, cost, and surgical complexity between RSA for proximal humerus fracture vs. elective indications for chronic arthropathy pathologies.

Furthermore, it has been previously described in the literature that specific indications for RSA correlate to expected patient outcomes following surgical treatment. For example, a previous systematic review by Paras et al¹⁵ evaluating patient-reported outcome measures for patients who underwent RSA for 3- and 4-part proximal humerus fractures and for patients who underwent RSA for elective indications found that RSA for fracture patients had poorer outcome scores than their elective counterparts.¹⁵ Another study by Malik et al¹³ analyzed the National Surgical Quality Improvement Program (NSQIP) database and noted similar findings citing longer LOS, higher rates of complication, revision, and readmission within the first 30 postoperative days.

We found the RSA for fracture group required more hospital services, with 32% of patients requiring disposition to rehabilitation or skilled nursing facility placement (32% vs. 9%, P <.01), longer lengths of hospital stay (4.0 vs. 1.8 days, P = .004), greater mean operative time (143 vs. 108 minutes, P < .001), and $19,630 higher charges per patient (P = .0002) than those indicated for RSA with chronic arthropathy etiologies. Although understanding the difference in the cost and charges between groups is likely multifactorial and difficult to fully appreciate, it is clear that patients undergoing RSA for fracture use more hospital resources; additional inpatient time, and increased care from nursing; physical therapists, social work, and case management during the postoperative period.

Patient outcomes

Patients with chronic arthropathy pathologies indicated for RSA had significantly better aFF and aER at the 2- and 6-month time points with close but no significant difference at 12 months for aFF (P = .06). Active aER was significantly better in this group as well. These findings may highlight the time-dependent nature of recovery to allow for tuberosity healing prior to regaining motion. In addition, the significant difference in aER may be explained by tuberosity malunion or poor residual posterior cuff strength. Gallinet et al⁷ demonstrated in their series the importance of tuberosity repair, with 12 of 16 patients who underwent reverse for fracture without tuberosity repair having 0° of aER at a mean follow-up of 12.4 months.

Looking at VAS pain scores, they did not differ significantly between groups at any time point postoperatively. On average, all patient-reported postoperative VAS scores improved compared with preoperative scores in both groups. In the immediate 90-day postoperative period, RSA for fractures had a higher revision rate than RSA for arthropathy (4% vs. 3%, P = .87). Specifically, those in the chronic arthropathy group experienced revisions primarily for dislocation/instability (60%) and infection (40%), whereas the fracture group revisions were exclusively for instability. At 24 months, all-cause revision rates were similar between the fracture and arthropathy groups, respectively (7% vs. 6% , P =.81). Indications for all-cause revision within the arthropathy group included instability (50%), infection (20%), aseptic loosening (20%), and periprosthetic fracture (10%); instability (100%) remained the only indication within the fracture group to result in revision surgery. Our findings echo Boileau’s study,⁴ which identified instability as the leading revision cause in a cohort of 825 RSAs. Overall, RSA for fracture exhibited a similar 2-year revision rate as the comparison group, with a nonsignificant trend toward higher revision within the global period.

There are several limitations to this study. First, our study design lacks an assessment of validated patient-reported outcome scores such as the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score. Moreover, the retrospective nature of this analysis may introduce bias. In addition, the inability to control for patient comorbidities, with nearly 70% of patients in both groups being ASA class 3 or greater, may not be generalizable to non–tertiary center patient populations like ours. In addition, multiple implants were used throughout the study period, which may have an influence on the hospital-accounted cost and charges. Furthermore, our inclusion criteria for selecting patients who underwent RSA for elective indications led to a highly heterogenous study population with varying indications for surgery, which may affect the reported outcomes and complication rates. Last, long-term outcomes and implant survivorship was not included in this analysis. Future study should aim to assess validated patient-reported outcome measures for these 2 groups.

Our investigation aimed to highlight some of the dissimilarities in not only patient-specific factors but also the operative logistics, postoperative hospital course, and postoperative outcomes following RSA for the purposes of treatment of acute proximal humerus fractures as compared to other elective indications for RSA. We feel these differences warrant further investigation and may influence creation of a separate CPT code, similarly to what is currently available for proximal femur fractures—hemiarthroplasty for arthrosis (CPT 27125) vs. fracture (CPT 27236). This would allow for a more accurate and transparent coding and billing, as well as appropriate appreciation for the increased technical complexity and representation of the increased resource utilization.

Conclusion

Our study demonstrates that RSA for fractures and arthropathy indications share a CPT code but have substantial differences in patient medical complexity, surgical complexity, hospital resource utilization, and early revision rates within the global period. These may be important to consider given the currently available CPT code that does not differentiate indications for RSA, especially if intending to accurately and thoroughly document the surgical care provided.