Preoperative Evaluation and Postoperative Care of the Orthopaedic Patient

Elaine I. Yang, MD

Alexander S. McLawhorn, MD, MBA

Dr. Yang or an immediate family member serves as a paid consultant to or is an employee of Intellijoint and Johnson & Johnson. Neither Dr. McLawhorn nor any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly to the subject of this chapter.

ABSTRACT

Increasing patient complexity in the face of outcome-based cost-containment efforts necessitate a thorough but efficient preoperative assessment process. Unnecessary preoperative testing due to poor compliance with clinical guidelines can and often delay surgery while driving up health care costs. To avoid this, institutions should develop preoperative care pathways founded on sound and up-to-date evidence and ensure high compliance among its team members. In regard to orthopaedic trauma patients, proper evaluation should include appropriate triaging of care, timing of surgery, and utilization of resources; adherence to practice guidelines for geriatric trauma patients is of particular importance in these regards because of high associated morbidity and mortality. Postoperatively, optimal pain management should include the use of multimodal analgesia and a sensible and balanced approach to pharmacologic treatment with deterrence of opioid prescriptions whenever possible. Success requires collaboration between all the members of the perioperative team as well as organizational consistency.

Keywords: geriatric trauma; multimodal analgesia; presurgical testing; surgical risk stratification; trauma injury assessment

Introduction

The increasing population of aging Americans continues to drive the volume of orthopaedic procedures nationwide. Despite this, perioperative care of the orthopaedic patient remains inconsistent and contradictory. This has in turn led to two extremes—surgical delays as well as increased length of stay due to inadequate optimization. Sheffield et al estimated that over 56,000 Medicare patients underwent unnecessary cardiac workup before surgery, and Abbas et al demonstrated that even within a single institution, there was very little consistency in adherence to proposed guidelines for patients with acute proximal femur fractures.¹^,² With recent pressure from government-mandated cost-containment programs, proper risk stratification and efficient utilization of resources are imperative.

Preoperative Assessment

Revised Cardiac Risk Index

Cardiac risk stratification is an important part of shared surgical decision-making as it evaluates a patient’s surgical candidacy and engenders appropriate risk/benefit discussions. The Revised Cardiac Risk Index (RCRI) proposed by Lee et al and modified by the ACC/AHA Task Force uses a 6-point scale³ (Table 1). Patients with no positive predictors have a perioperative risk of 0.4% of a major cardiovascular complication (MCC). Those with predictors 1, 2, ≥3 have a 0.9%, 6.6%, and >11% risk of MCC, respectively. Despite its universality, recent studies suggest that the RCRI has low discriminative ability and has been inconsistent in predicting the rate of MCC.⁴ In light of these findings, strides have been made to develop new propensity scales to improve the prediction of major adverse events.

American College of Surgeons NSQIP MICA

In 2011, Gupta et al devised a cardiac morbidity calculator to determine the risk of postoperative myocardial
infarction and cardiac arrests (MICA).⁵ Gupta’s study, which was validated on a cohort of 40,000 patients from the NSQIP database, showed that risk factors most predictive of MICA after surgery were American Society of Anesthesiologists (ASA) classification, dependent functional status, age, abnormal creatinine (>1.5), and type of surgery.

Table 1 Revised Cardiac Risk Index and Risk of MCC

RCRI Criteria (1-6)	Predictors	Risk of MCC
1. History of ischemic heart disease	0	0.4%
2. History of congestive heart failure	1	0.9%
3. History of cerebrovascular disease	2	6.6%
4. History of diabetes	≥3	>11%
5. Chronic kidney disease (creatinine >2 mg/dL)
6. Undergoing intermediate/high-risk surgery^a
^aRefers to suprainguinal vascular surgery, intraperitoneal surgery, and intrathoracic surgery.
MCC = major cardiovascular complications, including death, myocardial infarction, and nonfatal cardiac arrest, RCRI = Revised cardiac risk index Data from Lee TH, Marcantonio ER, Mangione CM, et al: Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation 1999;100(10):1043-1049.

Total Joint Arthroplasty Cardiac Risk Index

Similarly in 2016, Waterman et al formulated and tested a cardiac risk index (Total Joint Arthroplasty Cardiac Risk Index, TJA CRI) specific to total joint arthroplasty patients. It is based on three primary predictors: age ≥80 years, history of hypertension, and a history of cardiac disease.⁶ He was able to demonstrate not only that each factor independently predicted postoperative MCC more discriminately than the RCRI, but also that patients with all three predictors had the highest MCC risk.

Modified Frailty Index

Elderly patients pose a challenge to universal risk stratification because of the concept of frailty, defined as a decrease in physiologic reserves and accumulation of multisystem impairments separate from the normal process of aging. The Canadian Study of Health and Aging (CSHA) first introduced the Modified Frailty Index (mFI)⁷ for all surgical patients; it was modified in 2016 and applied to approximately 40,000 NSQIP primary total joint arthroplasty patients.⁸ Eleven variables from the CSHA-FI, matched to those from the NSQIP, were taken and each assigned one point (Table 2). The mFI score is calculated by dividing the total number of positive risk factors by 11, ranging from 0.0 to 1.0. Shin et al showed that an mFI score of ≥0.45 independently predicts major postoperative complications and is effective in guiding appropriate postoperative destination.

Table 2 Canadian Study of Health and Aging-Frailty Index Versus National Surgical Quality Improvement Program

CSHA-FI Variables	NSQIP
Congestive heart failure (1 point)	Congestive heart failure
Myocardial infarction (1 point)	Myocardial infarction
Cardiac problems (1 point)	Angina or cardiac stents
Arterial hypertension (1 point)	Hypertension requiring medication
Cerebrovascular problems (1 point)	Transient ischemic attack
History of stroke (1 point)	Cerebrovascular accident
Decreased peripheral pulses (1 point)	Peripheral vascular disease
Respiratory problems (1 point)	Chronic obstructive pulmonary disease
Diabetes mellitus (1 point)	Diabetes mellitus
Changes in ability to perform ADLs (1 point)	Nonindependent functional status
Clouding or delirium (1 point)	Impaired sensorium
ADLs = activities of daily living Adapted from Shin JI, Keswani A, Lovy A, et al: Simplified frailty index as a predictor of adverse outcomes in total hip and knee arthroplasty. J Arthroplasty 2016;31[11]:2389-2394. Copyright 2016, with permission from Elsevier.

Presurgical Testing

Cardiac and pulmonary testing comprise most preoperative resources used and can be confounding because of ongoing updates. Below is a summary of the ACC/AHA approach to preoperative testing based on the 2014 Perioperative Guidelines and the 2016 focused update on the preoperative management of preexisting cardiac stents.⁹^,¹⁰

Electrocardiogram

In any patient (with or without known cardiac comorbidities) undergoing low-risk surgery, the ACC/AHA does not currently recommend routine resting 12-lead electrocardiograms (ECG) before surgery. It is, however, recommended for all patients undergoing intermediate or high-risk surgery.

Echocardiogram

Asymptomatic patients without cardiac comorbidities need not undergo routine assessment of left ventricular (LV) function. The same applies for patients with known cardiac history who have undergone LV assessment within the last year. It is, however, reasonable to ascertain preoperative LV function in any patient without cardiac history with unexplained dyspnea, and in any patient with known cardiac structural abnormalities who has worsening symptoms of heart failure or who has not undergone reevaluation within the past year.

Exercise/Pharmacologic Stress Testing

Excellent functional status is a reliable predictor of perioperative success. As such, patients, regardless of medical risk factors, need not undergo preoperative stress testing if they can perform above 4 metabolic equivalents (METs). Functional capacity is divided into excellent (>10 METs), good (7 to 10 METs), moderate (4 to 6 METs), and poor (<4 METs) (Table 3). Conversely, in patients who cannot perform 4 METs or in whom the functional status is unknowable, it is reasonable to perform preoperative stress testing. The only exception is if the patient is undergoing low-risk surgery, in which case it is at the discretion of the perioperative physicians to decide if the results of the testing will alter intraoperative management, thereby justifying its use.

Table 3 Metabolic Equivalent (MET) Designations

MET	Examples	Stress Testing (Y/N)
Unknown	Unable to walk because of physical disability or pain	Yes
Poor (<4)	Walk 2-3 mph; can perform ADLs	Yes
Moderate (4-6)	Walk 4 mph, two flight of stairs	No
Good (7-10)	Run a short distance	No
Excellent (>10)	Run a long distance	No
ADLs = activities of daily living

Chest Radiograph

The value of preoperative testing to estimate postoperative pulmonary risk continues to be controversial. A thorough history and physical remains the most proven tool in identifying high-risk patients. As it stands, local institutional guidelines are what drive the routine use of screening chest radiographs before surgery. Limited evidence from multivariable risk factor studies does support the use of preoperative chest radiography for patients with known pulmonary disease as well as those older than 50 years undergoing intermediate or high-risk surgery.¹¹

Advanced Pulmonary Testing

Spirometry may provide some risk stratification in vulnerable patients but, given the cost, does not add value as a routine tool to estimate postoperative pulmonary risk. Although there are currently no evidence-supported guidelines available, conventional practice advocates the use of spirometry in patients with known obstructive or restrictive lung disease to assess disease progression and to estimate risk. It is also not unreasonable to order preoperative spirometry on patients with no known disease but newly identified with abnormal chest radiograph or dyspnea of unclear etiology.¹²

Approach to Patients With Cardiac Stenting

Balloon Angioplasty and Bare Metal Stents

Patients with coronary angiography should wait a minimum of 2 weeks after balloon angioplasty before proceeding with elective surgery and should continue their aspirin perioperatively. If bare metal stents (BMSs) are placed, the patient should be observed for a minimum of 30 days before proceeding. Those needing nonelective surgery will require a consensus decision by perioperative physicians to decide on the timing of surgery in relation to the risk of coronary thrombosis.

Drug-Eluting Stents

Before 2016, patients who underwent placement of coronary drug-eluting stents (DESs) needed to wait a minimum of 1 year before proceeding with elective noncardiac surgery because of the theoretical risk of
stent thrombosis in patients for whom dual antiplatelet therapy is prematurely discontinued. Several large studies have since suggested that the risk of thrombosis is less than previously thought.¹³^,¹⁴^,¹⁵ Since the 2016 focused update, the ACC/AHA now states that patients can proceed with elective surgery 6 months after DES placement. Dual antiplatelet therapy should be continued perioperatively whenever possible, but in the event that it needs to be discontinued, the ACC/AHA advises continuing at least aspirin and restarting the P2Y₁₂ inhibitor as soon as possible.

Perioperative Surveillance

As of 2014, routine postoperative myocardial infarction screening with troponins and ECG in asymptomatic patients with cardiac risk factors remain controversial and without established benefits. Currently, the ACC/AHA recommends that postoperative troponins and ECG be primarily reserved for symptomatic patients. At many institutions it is at the discretion of the patient’s cardiologist or intensivist whether postoperative screening ECGs and troponins are ascertained in selected patients.

Evaluation of the Orthopaedic Trauma Patient

Injury Severity Assessment

Comprehensive approach to the trauma patient should begin with an accurate assessment of injury severity. This is essential not only for appropriate triaging and allocation of resources but also for evaluating changes over time and outcome prognostication. To achieve this end, trauma scoring has undergone many alterations since its inception; despite the efforts of many, there is currently no universally accepted and applicable scoring system. We review the most widely used scoring systems below along with potential pitfalls involved in their use.

Glasgow Coma Scale

Described by neurosurgeons from the University of Glasgow in 1974, the Glasgow Coma Scale (GCS) was originally developed as a tool to assess consciousness after traumatic brain injury, but now has been incorporated into more complex scoring systems as a way to assess neurologic status after acute injury.¹⁶ The scale comprises three graded components: (1) eye response (1 to 4 points), (2) verbal response (1 to 5 points), and (3) motor response (1 to 6 points). Higher points are awarded to responses indicative of advanced cortical function, whereas lower points signify the absence of even basic brain stem reflexes.

Injury Severity Score

Developed as a revision of the Abbreviated Injury Scale (AIS), which was one of the first injury-description systems ever developed but with many limitations, the Injury Severity Score (ISS) was created by Baker et al in 1974 to better assess injury severity in patients with polytrauma.¹⁷ The ISS uses the AIS, which assigns points 1 to 5 in increasing severity for trauma to any of the nine regions of the body, as the basis for its scoring. The AIS scores for the three most severely injured areas of the body are squared and added together to yield the ISS score (1 to 75). Although this method predicts mortality better than the AIS and remained for many decades the most widely used model, its shortcoming is that it does not allow assessment of multiple injuries to the same body region. A revised version of the ISS, called the New Injury Severity Score (NISS), was developed in 1997 and addresses some of its previous deficiencies.

Trauma and Injury Severity Score

Historical trauma scoring systems primarily focused on anatomic variables, not taking into account that the physiologic course after injury is often highly dynamic and can profoundly affect outcomes. The Trauma and Injury Severity Score (TRISS) was developed to encompass both physiologic and anatomic data into the scoring system. A method that incorporates the (1) Trauma Score—a physiologic scale devised by Champion et al in 1981, (2) the ISS—primarily an anatomic survey of injury, and (3) patient age, TRISS has shown improved injury assessment and predictive abilities toward survival compared with its predecessors.¹⁸ However, as it uses the ISS in its calculation, TRISS is limited by the same problems as the ISS.

Trauma Mortality Prediction Model

The Trauma Mortality Prediction Model (TMPM) was devised in 2008 as a mathematical model that employs severity values called model-average regression coefficients (MARC) derived from 1,322 AIS injury codes to predict mortality after trauma.¹⁹ In 2009, the same model was applied to ICD-9 codes and found to have similar predictive abilities. These two methodologies have been compared with the ISS, the International Classification of Diseases-based ISS (ICISS), the NISS, and the Single-Worst Injury model (SWI) and have shown superior mortality prediction.²⁰^,²¹ The downside of using such a model is its complexity in calculation as it uses large sets of trauma data.

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