
==== Front
Eur J Orthop Surg Traumatol
Eur J Orthop Surg Traumatol
European Journal of Orthopaedic Surgery & Traumatology
1633-8065
1432-1068
Springer Paris Paris

39133255
4054
10.1007/s00590-024-04054-x
Original Article
The association of hyponatremia and early postoperative complications in aseptic revision total shoulder arthroplasty
http://orcid.org/0000-0002-0060-6593
Liu Steven H. steven.h.liu@gmail.com

1
Bramian Allen 2
Loyst Rachel A. 2
Kashanchi Kevin 1
Wang Edward D. 2
1 grid.42505.36 0000 0001 2156 6853 Department of Orthopaedics, Keck Medicine of University of Southern California, 1540 Alcazar Street CHP 207, Los Angeles, CA 90089-9007 USA
2 https://ror.org/05qghxh33 grid.36425.36 0000 0001 2216 9681 Department of Orthopaedics, Stony Brook University, Stony Brook, NY USA
12 8 2024
12 8 2024
2024
34 6 32513257
16 6 2024
31 7 2024
© The Author(s) 2024
2024
https://creativecommons.org/licenses/by/4.0/ Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Purpose

This study investigates the association between preoperative serum sodium levels and 30-day postoperative complications following aseptic revision total shoulder arthroplasty (TSA).

Methods

The American College of Surgeons National Surgical Quality Improvement Program database was queried for all patients who underwent aseptic revision TSA from 2015 to 2022. The study population was divided into two groups based on preoperative serum sodium levels: eunatremia (135–144 mEq/L) and hyponatremia (< 135 mEq/L). Logistic regression analysis was performed to investigate the relationship between hyponatremia and early postoperative complications.

Results

Compared to eunatremia, hyponatremia was independently associated with a significantly greater likelihood of experiencing any complication (odds ratio [OR] 1.65, 95% confidence interval [CI] 1.14–2.40; P = .008), blood transfusions (OR 2.45, 95% CI 1.24–4.83; P = .010), unplanned reoperation (OR 2.27, 95% CI 1.07–4.79; P = .032), and length of stay > 2 days (OR 1.63, 95% CI 1.09–2.45; P = .017).

Conclusion

Hyponatremia was associated with a greater rate of early postoperative complications following noninfectious revision TSA. This study sheds light on the role of preoperative hyponatremia as a risk factor for postoperative complications and may help surgeons better select surgical candidates and improve surgical outcomes in the setting of revision TSA.

Keywords

Revision total shoulder arthroplasty
Total shoulder arthroplasty
Hyponatremia sodium
Complications
University of Southern CaliforniaOpen access funding provided by SCELC, Statewide California Electronic Library Consortium

issue-copyright-statement© Springer-Verlag France SAS, part of Springer Nature 2024
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pmcIntroduction

Revision total shoulder arthroplasty is often indicated to treat complications associated with primary total shoulder arthroplasty (TSA) [1]. Recent studies have reported a concurrent rise in primary and revision TSA [2–4]. A recent systematic review and meta-analysis reported high complication rates following revision TSA [5]. The rise in revision TSA volume and associated postoperative complications warrants investigation into preoperative factors that may serve as predictors of postoperative complications following revision TSA.

Hyponatremia, defined as a serum sodium level below 135 mEq/L, is an electrolyte abnormality that leads to symptoms ranging from headache and nausea to seizures and coma. Studies have demonstrated an association between preoperative hyponatremia and morbidity and mortality following both orthopedic and non-orthopedic surgery [6–8]. A study investigating the relationship between preoperative hyponatremia and postoperative complications following aseptic revision hip and knee arthroplasty revealed hyponatremia to be an independent risk factor for multiple postoperative complications [9]. Another study reported associations between preoperative hyponatremia and postoperative complications in primary TSA [8].

Hyponatremia as a preoperative risk factor may exacerbate the already relatively high complication rates associated with revision TSA. Yet, there is a paucity of literature studying the effects of hyponatremia in the setting of revision TSA. This study aims to determine the relationship between preoperative hyponatremia and 30-day postoperative complications following revision TSA. We hypothesized that hyponatremia would be associated with higher rates of 30-day postoperative complications following revision TSA.

Materials and methods

We queried the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database for all patients who underwent revision TSA from 2015 to 2022. This study was exempt from approval by our University’s Institutional Review Board as the NSQIP database is fully deidentified. Data in the NSQIP database are gathered from over 600 hospitals in the USA by trained surgical clinical reviewers [10].

The Current Procedural Terminology (CPT) codes 23,473 and 23,474 were used to identify 2,619 patients who underwent revision TSA from 2015 to 2022 (Fig. 1). The NSQIP database excludes all cases for patients younger than 18 years of age and those with primary admission related to trauma. Initially, 209 revision TSA cases were excluded as revision was performed due to an infectious primary etiology. We opted to exclude revisions performed for an infectious indication because the NSQIP database lacks details regarding the nature of the infection (i.e., acute vs. chronic), which may significantly impact postoperative complication rates. Next, 435 cases were excluded due to either missing preoperative sodium measurements or sodium measurements not belonging in the eunatremia or hyponatremia ranges. Additionally, 48 cases were excluded for unknown information relating to height/weight, the American Society of Anesthesiologists (ASA) classification, functional health status, or sex. The final patient population included in the study after applying exclusion criteria was 1,927. These cases were then separated based on serum sodium levels into eunatremia (135–144 mEq/L) and hyponatremia (< 135 mEq/L) cohorts: 1,791 patients in eunatremia and 136 patients in hyponatremia.Fig. 1 Case selection schematic detailing patient selection process for revision total shoulder arthroplasty (TSA) from 2015 to 2022. TSA, total shoulder arthroplasty; NSQIP, National Surgical Quality Improvement Program; ASA, American Society of Anesthesiologists

Variables collected in this study included patient demographics, comorbidities, surgical characteristics, and 30-day postoperative complication data. Patient demographics included sex, age, body mass index (BMI), functional status, ASA classification, smoking status, and preoperative steroid use. Preoperative comorbidities included congestive heart failure (CHF), diabetes mellitus, hypertension, severe chronic obstructive pulmonary disease (COPD), bleeding disorders, and disseminated cancer. Perioperative factors included total operation time. Thirty-day complications included the following: sepsis, septic shock, pneumonia, unplanned reintubation, urinary tract infection (UTI), cardiac arrest or myocardial infarction (MI), stroke, blood transfusions, deep-vein thrombosis (DVT), pulmonary embolism (PE), on ventilator > 48 h, surgical space infection (SSI), wound dehiscence, acute renal failure, Clostridioides difficile (C. diff) infection, nonhome discharge, readmission, unplanned reoperation, periprosthetic fracture, length of stay (LOS) > 2 days, and mortality.

Statistical analyses were performed using Python version 3.8 with the Statsmodels Python package. Bivariate logistic regression was used to compare patient demographics and comorbidities between the two groups. Multivariate logistic regression, adjusted for all patient demographics and comorbidities significantly associated with hyponatremia, was used to identify significant independent associations between hyponatremia and postoperative complications. Odds ratios (ORs) were reported with 95% confidence intervals (CI). The level of statistical significance was set at P < 0.05.

Results

Compared to eunatremia, hyponatremia was significantly associated with BMI less than 24.9 kg/m2 (P = 0.004), dependent functional status prior to surgery (P = 0.000), and comorbid hypertension (P = 0.006) (Table 1). Table 1 Demographics and comorbidities of patients with eunatremia and hyponatremia. Bold P values indicate statistical significance with P < .05

	Eunatremia
(135–144 mEq/L)	Hyponatremia
(< 135 mEq/L)		
Characteristics	Number (%)	Number (%)	P value	
Overall	1791 (100.0)	136 (100.0)		
Sex			0.750	
Female	936 (52.3)	73 (53.7)		
Male	855 (47.7)	63 (46.3)		
Age			0.339	
18–39	12 (0.7)	2 (1.5)		
40–59	297 (16.6)	18 (13.2)		
60–79	1284 (71.7)	97 (71.3)		
 ≥ 80	198 (11.1)	19 (14.0)		
BMI (kg/m2)			0.004	
 < 18.5	7 (0.4)	1 (0.7)		
18.5–24.9	270 (15.1)	36 (26.5)		
25–29.9	548 (30.6)	36 (26.5)		
 ≥ 30	966 (53.9)	63 (46.3)		
Functional status prior to surgery			0.000	
Dependent	52 (2.9)	13 (9.6)		
Independent	1739 (97.1)	123 (90.4)		
ASA classification			0.056	
 ≤ 2	647 (36.1)	38 (27.9)		
 ≥ 3	1144 (63.9)	98 (72.1)		
Smoker			0.894	
No	1600 (89.3)	121 (89.0)		
Yes	191 (10.7)	15 (11.0)		
Steroid use			0.223	
No	1678 (93.7)	131 (96.3)		
Yes	113 (6.3)	5 (3.7)		
Comorbidities				
CHF	32 (1.8)	3 (2.2)	0.725	
Diabetes	0 (0.0)	0 (0.0)	0.903	
Hypertension	1203 (67.2)	107 (78.7)	0.006	
COPD	137 (7.6)	11 (8.1)	0.853	
Bleeding disorder	61 (3.4)	6 (4.4)	0.538	
Disseminated cancer	5 (0.3)	0 (0.0)	0.995	
Total operation time (minutes)			0.383	
0–79	396 (22.1)	31 (22.8)		
80–128	709 (39.6)	60 (44.1)		
 ≥ 129	686 (38.3)	45 (33.1)		
BMI, body mass index; ASA, American Society of Anesthesiologists; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease

Compared to eunatremia, hyponatremia was significantly associated with a greater likelihood of experiencing any complication (P = 0.000), blood transfusions (P = 0.001), nonhome discharge (P = 0.004), unplanned reoperation (P = 0.021), and LOS > 2 days (P = 0.001) (Table 2). Table 2 Bivariate analysis of 30-day postoperative complications in patients with eunatremia and hyponatremia. Bold P values indicate statistical significance with P < .05

	Eunatremia
(135–144 mEq/L)	Hyponatremia
(< 135 mEq/L)		
Complications	Number (%)	Number (%)	P value	
Any complication	461 (25.7)	54 (39.7)	0.000	
Sepsis	11 (0.6)	1 (0.7)	0.863	
Septic shock	1 (0.1)	0 (0.0)	0.851	
Pneumonia	3 (0.2)	0 (0.0)	0.988	
Unplanned reintubation	3 (0.2)	0 (0.0)	0.988	
UTI	12 (0.7)	1 (0.7)	0.929	
Cardiac arrest or MI	8 (0.4)	0 (0.0)	0.998	
Stroke	0 (0.0)	0 (0.0)	–	
Blood transfusions	54 (3.0)	12 (8.8)	0.001	
DVT	10 (0.6)	0 (0.0)	1.000	
PE	10 (0.6)	1 (0.7)	0.792	
On ventilator > 48 h	1 (0.1)	0 (0.0)	0.851	
SSI	47 (2.6)	5 (3.7)	0.468	
Wound dehiscence	4 (0.2)	0 (0.0)	0.999	
Acute renal failure	3 (0.2)	0 (0.0)	0.988	
Clostridioides difficile infection	2 (0.1)	0 (0.0)	0.999	
Nonhome discharge	118 (6.6)	18 (13.2)	0.004	
Readmission	80 (4.5)	8 (5.9)	0.447	
Unplanned reoperation	52 (2.9)	9 (6.6)	0.021	
Periprosthetic fracture	0 (0.0)	0 (0.0)	–	
LOS > 2 days	317 (17.7)	40 (29.4)	0.001	
Mortality	2 (0.1)	0 (0.0)	0.999	
UTI, urinary tract infection; MI, myocardial infarction; DVT, deep-vein thrombosis; PE, pulmonary embolism; SSI, surgical site infection; LOS, length of stay

After controlling for all associated patient demographic and comorbid factors (BMI, functional status, and comorbid hypertension), an adjusted multivariate regression analysis was conducted. Compared to eunatremia, hyponatremia was independently associated with a significantly greater likelihood of experiencing any complication (odds ratio [OR] 1.65, 95% confidence interval [CI] 1.14–2.40; P = 0.008), blood transfusions (OR 2.45, 95% CI 1.24–4.83; P = 0.010), unplanned reoperation (OR 2.27, 95% CI 1.07–4.79; P = 0.032), and LOS > 2 days (OR 1.63, 95% CI 1.09–2.45; P = 0.017). (Table 3). Table 3 Multivariate analysis of 30-day postoperative complications in patients with eunatremia and hyponatremia. Bold P values indicate statistical significance with P < .05

Complications	OR, P value, (95% CI)	
Any complication	1.65, 0.008, (1.14–2.40)	
Blood transfusions	2.45, 0.010, (1.24–4.83)	
Nonhome discharge	1.66, 0.074, (0.95–2.90)	
Unplanned reoperation	2.27, 0.032, (1.07–4.79)	
LOS > 2 days	1.63, 0.017, (1.09–2.45)	
LOS, length of stay

Discussion

This study investigated hyponatremia as a risk factor for 30-day complications following revision TSA. Investigation of 1,927 patients from the NSQIP database who underwent revision TSA between the years of 2015 and 2022 revealed hyponatremia to be significantly associated with a higher rate of 30-day postoperative complications. Relative to eunatremia, hyponatremia was found to be an independently significant predictor of any complication, blood transfusions, unplanned reoperation, and postoperative hospital stay lasting longer than 2 days following revision TSA.

Hyponatremia is the most common electrolyte abnormality encountered in clinical practice and represents a disruption of water balance resulting in excess water relative to total body sodium content [11]. Sodium is the primary cation in the extracellular fluid and plays a role in numerous physiological processes [12]. As such, disruptions in serum sodium levels may lead to many symptoms ranging from headache to seizures and may ultimately lead to death [13]. Hyponatremia can lead to cellular dysfunction by causing osmotic imbalances, resulting in intracellular swelling and edema. In the context of surgery, tissue edema can compromise wound healing and increase the risk of infection. Additionally, hyponatremia is often associated with other electrolyte imbalances such as hypokalemia. These imbalances can predispose patients to cardiac arrhythmias, which can complicate the perioperative and postoperative periods. Although the full impact of hyponatremia is not entirely understood, healthcare providers recognize the crucial importance of detecting and correcting hyponatremia before revision total shoulder arthroplasty.

Hyponatremia, defined as a serum sodium concentration below 135 mEq/L, has been identified as a preoperative prognostic marker for perioperative 30-day morbidity and mortality in a wide range of surgical specialties [6]. Furthermore, studies have linked preoperative hyponatremia to 30-day postoperative complications following orthopedic procedures, including lumbar, shoulder, hip, and knee surgery [7–9, 14, 15]. This study provides evidence for preoperative hyponatremia as an independent predictor of 30-day postoperative complications following revision TSA.

Reported rates of blood transfusions following primary TSA vary, with studies reporting rates of up to 6.7% for primary TSA and up to 31% for revision TSA [16, 17]. Our study reports a greater than twofold increase in the risk of receiving blood transfusions in the hyponatremic group compared to the eunatremic group following revision TSA. In addition, 8.8% of the hyponatremic group received blood transfusions following revision TSA as compared to 3.0% in the eunatremic group. In general, revision TSA has an inherently higher risk of requiring blood transfusions and hyponatremia may exacerbate the need for blood transfusions in an already vulnerable population [17].

Relative to eunatremia, hyponatremia was associated with a greater than twofold increase in the risk of undergoing unplanned reoperation following revision TSA. A study on serious adverse events following revision TSA found that 41% of the reported perioperative complications occurred during an unplanned reoperation [3], highlighting the notion that a noteworthy proportion of all serious adverse events related to revision TSA occur during reoperation. Since preoperative hyponatremia is a significant predictor of unplanned reoperation in revision TSA patients, hyponatremia is a laboratory abnormality that should be factored into a patient’s preoperative risk determination to avoid further surgery and precipitously worse outcomes.

Nevertheless, comorbidities such as CHF and low body weight have been reported as predictors of increased length of stay following orthopedic procedures [18]. Our study, which controlled for differences in patient BMI, revealed that hyponatremia was associated with a greater than 1.5-fold likelihood of experiencing a hospital stay lasting greater than 2 days. Therefore, hyponatremia may have utility as a prognostic indicator for identifying cases at risk of prolonged hospital stays with the goal of decreasing surgical costs, increasing patient satisfaction, and decreasing nosocomial infections.

In the context of major surgery, preoperative hyponatremia is a prognostic marker for perioperative 30-day morbidity and mortality [6]. Specifically, it is associated with major morbidity and prolonged hospitalization in spine surgery, as well as SSIs, blood transfusions, pneumonia, sepsis, extended length of stay, wound, pulmonary, and infectious complications in aseptic revision hip and knee arthroplasty [7, 9]. Furthermore, preoperative hyponatremia has been associated with reoperation and prolonged hospitalization in total knee arthroplasty [19]. A study investigating hyponatremia in TSA reported similar associations between hyponatremia and major morbidity, prolonged length of stay, nonhome discharge, and readmission [8]. Altogether, the findings of this study align with preexisting orthopedic literature and extend our understanding of preoperative hyponatremia as a risk factor for early postoperative complications to the setting of revision TSA.

Postoperative care protocols, such as early mobilization, pain management, infection prevention measures (e.g., antibiotic prophylaxis and wound care), and as this study emphasized, screening for hyponatremia, are crucial for improving surgical outcomes. Identifying and correcting hyponatremia preoperatively can prevent related complications like seizures, confusion, and delayed recovery. These protocols help reduce the risk of complications like deep-vein thrombosis, pulmonary embolism, and surgical site infections, while also enhancing recovery times and overall patient satisfaction. Effective postoperative care, including proactive management of hyponatremia, can significantly decrease morbidity and mortality, leading to better long-term health outcomes for patients.

Limitations to this study include use of the NSQIP database which includes information that is limited to a postoperative window of 30 days. As such, we are unable to report on longer-term complications associated with preoperative hyponatremia. In addition, variables including surgeon experience and the center at which procedures were performed are not available. Indications for revision TSA are not included in this database. Therefore, cases may not be stratified based on the risk associated with varying indications. Furthermore, laboratory artifact may falsely indicate hyponatremia as is the case in pseudohyponatremia. It is unknown whether cases of pseudohyponatremia were erroneously included in this database and thus used in our study. Despite these limitations, our study provides utility in providing evidence for hyponatremia as a risk factor for 30-day postoperative complications following revision TSA.

Conclusion

Our study identified preoperative hyponatremia as an independent predictor of 30-day postoperative complications following revision TlSA. As the utilization of primary and revision TSA continues to rise, preoperative laboratory values, including serum sodium levels, may offer benefit in risk stratification. By recognizing the risks associated with preoperative hyponatremia, surgeons may be better equipped to identify at risk surgical candidates and potentially correct modifiable preoperative risk factors.

Author contributions

All authors contributed to the study conception and design. Material preparation, data collection, and analysis were performed by Steven H. Liu and Rachel A. Loyst. The first draft of the manuscript was written by Steven H. Liu and Allen Bramian, and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Funding

Open access funding provided by SCELC, Statewide California Electronic Library Consortium.

Declarations

Conflict of interest

The authors have no relevant financial or non-financial interests to disclose.

Ethical approval

Ethical approval was not sought for the present study because this study was exempt from IRB approval. This study was completed in accordance with the Helsinki Declaration as revised in 2013.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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References

1. Boileau P Complications and revision of reverse total shoulder arthroplasty Orthop Traumatol Surg Res 2016 102 1 Suppl S33 43 10.1016/j.otsr.2015.06.031 26879334
Boileau P (2016) Complications and revision of reverse total shoulder arthroplasty. Orthop Traumatol Surg Res 102(1 Suppl):S33-43. 10.1016/j.otsr.2015.06.03126879334 10.1016/j.otsr.2015.06.031
2. Favard L Revision of total shoulder arthroplasty Orthop Traumatol Surg Res 2013 99 1 Suppl S12 21 10.1016/j.otsr.2012.11.010 23333127
Favard L (2013) Revision of total shoulder arthroplasty. Orthop Traumatol Surg Res 99(1 Suppl):S12-21. 10.1016/j.otsr.2012.11.01023333127 10.1016/j.otsr.2012.11.010
3. Keswani A Chi D Lovy AJ London DA Cagle PJ Jr Parsons BO Bosco JA Risk factors for and timing of adverse events after revision total shoulder arthroplasty Shoulder Elbow 2019 11 5 332 343 10.1177/1758573218780517 31534483
Keswani A, Chi D, Lovy AJ, London DA, Cagle PJ Jr, Parsons BO, Bosco JA (2019) Risk factors for and timing of adverse events after revision total shoulder arthroplasty. Shoulder Elbow 11(5):332–343. 10.1177/175857321878051731534483 10.1177/1758573218780517
4. Schwartz BE Savin DD Youderian AR Mossad D Goldberg BA National trends and perioperative outcomes in primary and revision total shoulder arthroplasty: trends in total shoulder arthroplasty Int Orthop 2015 39 2 271 276 10.1007/s00264-014-2614-5 25480662
Schwartz BE, Savin DD, Youderian AR, Mossad D, Goldberg BA (2015) National trends and perioperative outcomes in primary and revision total shoulder arthroplasty: trends in total shoulder arthroplasty. Int Orthop 39(2):271–276. 10.1007/s00264-014-2614-525480662 10.1007/s00264-014-2614-5
5. Ravi V Murphy RJ Moverley R Derias M Phadnis J Outcome and complications following revision shoulder arthroplasty : a systematic review and meta-analysis Bone Jt Open 2021 2 8 618 630 10.1302/2633-1462.28.BJO-2021-0092.R1 34382837
Ravi V, Murphy RJ, Moverley R, Derias M, Phadnis J (2021) Outcome and complications following revision shoulder arthroplasty : a systematic review and meta-analysis. Bone Jt Open 2(8):618–630. 10.1302/2633-1462.28.BJO-2021-0092.R134382837 10.1302/2633-1462.28.BJO-2021-0092.R1
6. Leung AA McAlister FA Rogers SO Jr Pazo V Wright A Bates DW Preoperative hyponatremia and perioperative complications Arch Intern Med 2012 172 19 1474 1481 10.1001/archinternmed.2012.3992 22965221
Leung AA, McAlister FA, Rogers SO Jr, Pazo V, Wright A, Bates DW (2012) Preoperative hyponatremia and perioperative complications. Arch Intern Med 172(19):1474–1481. 10.1001/archinternmed.2012.399222965221 10.1001/archinternmed.2012.3992
7. Pennington Z Bomberger TT Lubelski D Benzel EC Steinmetz MP Mroz TE Associations between preoperative hyponatremia and 30-day perioperative complications in lumbar interbody spinal fusion Clin Spine Surg 2021 34 1 E7 E12 10.1097/BSD.0000000000001016 32467442
Pennington Z, Bomberger TT, Lubelski D, Benzel EC, Steinmetz MP, Mroz TE (2021) Associations between preoperative hyponatremia and 30-day perioperative complications in lumbar interbody spinal fusion. Clin Spine Surg 34(1):E7–E12. 10.1097/BSD.000000000000101632467442 10.1097/BSD.0000000000001016
8. Lee RC Abola MV Du JY Tanenbaum JE Sivasundaram L Voos JE Bafus BT Preoperative hyponatremia is associated with postoperative major morbidity, prolonged length of stay, non-home discharge, and readmission in total shoulder arthroplasty Seminars Arthroplast: JSES 2020 30 2 162 168 10.1053/j.sart.2020.04.002
Lee RC, Abola MV, Du JY, Tanenbaum JE, Sivasundaram L, Voos JE, Bafus BT (2020) Preoperative hyponatremia is associated with postoperative major morbidity, prolonged length of stay, non-home discharge, and readmission in total shoulder arthroplasty. Seminars Arthroplast: JSES 30(2):162–168. 10.1053/j.sart.2020.04.00210.1053/j.sart.2020.04.002
9. Gu A Chen FR Chen AZ Fassihi SC Thakkar S Unger AS Liu J Sculco PK Ast MP Preoperative hyponatremia is an independent risk factor for postoperative complications in aseptic revision hip and knee arthroplasty J Orthop 2020 20 224 227 10.1016/j.jor.2020.01.028 32051674
Gu A, Chen FR, Chen AZ, Fassihi SC, Thakkar S, Unger AS, Liu J, Sculco PK, Ast MP (2020) Preoperative hyponatremia is an independent risk factor for postoperative complications in aseptic revision hip and knee arthroplasty. J Orthop 20:224–227. 10.1016/j.jor.2020.01.02832051674 10.1016/j.jor.2020.01.028
10. Harolds JA Quality and safety in health care, part XVII: the ACS national surgical quality improvement program Clin Nucl Med 2016 41 12 933 935 10.1097/RLU.0000000000001388 27749409
Harolds JA (2016) Quality and safety in health care, part XVII: the ACS national surgical quality improvement program. Clin Nucl Med 41(12):933–93527749409 10.1097/RLU.0000000000001388
11. Spasovski G Vanholder R Allolio B Annane D Ball S Bichet D Decaux G Fenske W Hoorn EJ Ichai C Joannidis M Soupart A Zietse R Haller M van der Veer S Van Biesen W Nagler E Hyponatraemia Guideline Development G Clinical practice guideline on diagnosis and treatment of hyponatraemia Eur J Endocrinol 2014 170 3 G1 47 10.1530/EJE-13-1020 24569125
Spasovski G, Vanholder R, Allolio B, Annane D, Ball S, Bichet D, Decaux G, Fenske W, Hoorn EJ, Ichai C, Joannidis M, Soupart A, Zietse R, Haller M, van der Veer S, Van Biesen W, Nagler E, Hyponatraemia Guideline Development G (2014) Clinical practice guideline on diagnosis and treatment of hyponatraemia. Eur J Endocrinol 170(3):G1-47. 10.1530/EJE-13-102024569125 10.1530/EJE-13-1020
12. Bernal A Zafra MA Simon MJ Mahia J Sodium homeostasis, a balance necessary for life Nutrients 2023 10.3390/nu15020395 37447238
Bernal A, Zafra MA, Simon MJ, Mahia J (2023) Sodium homeostasis, a balance necessary for life. Nutrients. 10.3390/nu1502039537447238 10.3390/nu15020395
13. Reynolds RM Padfield PL Seckl JR Disorders of sodium balance BMJ 2006 332 7543 702 705 10.1136/bmj.332.7543.702 16565125
Reynolds RM, Padfield PL, Seckl JR (2006) Disorders of sodium balance. BMJ 332(7543):702–705. 10.1136/bmj.332.7543.70216565125 10.1136/bmj.332.7543.702
14. Kayaokay K Yurtlu DA The incidence of hyponatremia in hospitalized patients due to hip fracture and its effect on mortality Cukurova Med J 2023 48 2 601 606 10.17826/cumj.1284848
Kayaokay K, Yurtlu DA (2023) The incidence of hyponatremia in hospitalized patients due to hip fracture and its effect on mortality. Cukurova Med J 48(2):601–60610.17826/cumj.1284848
15. Baker CM Goh GS Tarabichi S Sherman MB Khan IA Parvizi J Hyponatremia is an overlooked sign of trouble following total joint arthroplasty JBJS 2023 105 10 744 754 10.2106/JBJS.22.00928
Baker CM, Goh GS, Tarabichi S, Sherman MB, Khan IA, Parvizi J (2023) Hyponatremia is an overlooked sign of trouble following total joint arthroplasty. JBJS 105(10):744–75410.2106/JBJS.22.00928
16. Ryan DJ Yoshihara H Yoneoka D Zuckerman JD Blood transfusion in primary total shoulder arthroplasty: incidence, trends, and risk factors in the United States from 2000 to 2009 J Shoulder Elb Surg 2015 24 5 760 765 10.1016/j.jse.2014.12.016
Ryan DJ, Yoshihara H, Yoneoka D, Zuckerman JD (2015) Blood transfusion in primary total shoulder arthroplasty: incidence, trends, and risk factors in the United States from 2000 to 2009. J Shoulder Elb Surg 24(5):760–765. 10.1016/j.jse.2014.12.01610.1016/j.jse.2014.12.016
17. Saltzman BM Chalmers PN Gupta AK Romeo AA Nicholson GP Complication rates comparing primary with revision reverse total shoulder arthroplasty J Shoulder Elb Surg 2014 23 11 1647 1654 10.1016/j.jse.2014.04.015
Saltzman BM, Chalmers PN, Gupta AK, Romeo AA, Nicholson GP (2014) Complication rates comparing primary with revision reverse total shoulder arthroplasty. J Shoulder Elb Surg 23(11):1647–1654. 10.1016/j.jse.2014.04.01510.1016/j.jse.2014.04.015
18. Gholson JJ Noiseux NO Otero JE Gao Y Shah AS Patient factors systematically influence hospital length of stay in common orthopaedic procedures Iowa Orthop J 2017 37 233 237 28852363
Gholson JJ, Noiseux NO, Otero JE, Gao Y, Shah AS (2017) Patient factors systematically influence hospital length of stay in common orthopaedic procedures. Iowa Orthop J 37:233–23728852363
19. Abola MV Tanenbaum JE Bomberger TT Knapik DM Fitzgerald SJ Wera GD Preoperative hyponatremia is associated with reoperation and prolonged length of hospital stay following total knee arthroplasty J Knee Surg 2019 32 4 344 351 10.1055/s-0038-1641156 29618142
Abola MV, Tanenbaum JE, Bomberger TT, Knapik DM, Fitzgerald SJ, Wera GD (2019) Preoperative hyponatremia is associated with reoperation and prolonged length of hospital stay following total knee arthroplasty. J Knee Surg 32(4):344–351. 10.1055/s-0038-164115629618142 10.1055/s-0038-1641156
