Total hip arthroplasty (THA) is one of the true triumphs of modern medical science (1,2). For centuries people with disabling hip conditions could only look forward to living out their years in disabling pain. The relentless progression of hip disease led to a downward spiral of limited function for most patients unfortunate enough to be afflicted. Although early attempts at interpositional arthroplasty and resurfacing procedures routinely met with early failure, the advent of modern THA offers both surgeons and patients a reliable treatment for arthritis of the hip. Many debilitating hip processes, which eventually required crutch ambulation or wheelchair use, became treatable. With pain relieved, and function restored, most patients return to independent living without excessively burdening their family or society. Few medical interventions can claim such a benefit to the patient and society as a whole. As with most procedures, however, appropriate surgical indications are critical to a successful surgical outcome.

Long-term follow-up of THA has shown that at 25 years, 90% of patients retained the original femoral and acetabular components until the most recent follow-up or until death (3). With further improvements in operative techniques, instrumentation, and prosthetic design combined with a better understanding of the mechanisms of failure surgical results continue to improve. Given the success of this procedure, surgeons have expanded its indications for THA, and today over 332,000 THAs are performed in the United States annually (4); a testament to the ability of this procedure to relieve pain and improve function. The goal of this chapter is to define the indications and contraindications for THA. We will also try to define those factors which must be evaluated to determine for whom this procedure is most appropriate.

The terms “indications” and “contraindications,” while carrying the ring of specificity, actually represent the end points of a complex decision-making process which must be carried out by the medical practitioner in conjunction with the patient. Any medical decision making requires consideration of the potential risks and benefits of a particular intervention. This type of risk/benefit calculation is relatively uncomplicated for many diagnostic interventions, but there is clearly more at stake in most therapeutic interventions, particularly surgical ones.

Although there is a burgeoning literature devoted to the thought processes and rationale involved in medical decision making, there is no consensus on the specific methods which are most appropriately used to determine when a specific intervention is indicated. Surgical decision making represents a fascinating and complex subset of these processes, commonly undertaken to determine whether or not active intervention, and more specifically what type of intervention (as well as the appropriate timing of the intervention) is in the best interests of the patient. Wide variations noted in the rate of regional performance of multiple surgical techniques (including total joint replacement) demonstrate that “indications” are far from universally agreed upon for many surgical procedures. Clearly the consequences of surgical intervention must be carefully evaluated by both the patient and the surgeon, and in more complex cases may require the full range of the surgeon’s analytical skills as well as the ability to effectively communicate and educate the patient regarding the risks and benefits of a specific intervention so that they can be an active participant in the decision-making process.

The concept of indications can be defined as those situations where an individual patient will benefit from the intervention in such a way, and with sufficient likelihood, to warrant the specific risks involved in the intervention. Contraindications would connote the opposite, the risks involved, and/or the likelihood of the intervention’s failure to achieve the desired results, outweigh the expected benefit of the intervention. Determining whether or not a given procedure is indicated or contraindicated involves the careful evaluation of the patient’s complaints, pathology, and overall health status; the weighing of multiple probabilities for
various positive and adverse outcomes (many of which are at best based on less than adequate data); and finally some type of judgment as to whether the final balance of risks and benefits is appropriate for the individual patient under consideration. An important consideration in the performance of any elective surgical procedure is the relative risk of perioperative events which carry with it significant morbidity or mortality.

THA as initially practiced, and before the risk of venous thromboembolic (VTE) disease was well understood, carried with it a mortality risk from pulmonary embolism alone of up to 2% (6). Although this incidence has been substantially reduced, as have the initial rates of infection and other serious postsurgical morbidities, the surgeon contemplating elective surgical intervention must essentially compare the potential long-term benefits of pain reduction and improved function versus the short-term risks of death and other complications which may potentially occur following surgery.

A simple example of the trade-offs that must be evaluated is in the setting of pharmacologic intervention for VTE prophylaxis, where the benefits of a decrease in VTE events may be accompanied by an increased risk of serious bleeding complications. This type of “apples and oranges” comparison of both short- and long-term risks and potential complications with the expected short- and long-term benefits of a specific intervention is common in reconstructive surgical practice, and keeps much of surgical decision making in the realm of heuristic rather than algorithmic problem solving.

Various models of decision making have been evaluated to determine whether they represent a reasonable approximation of the way mature clinicians actually make clinical decisions. Although none of these models have been found to completely represent the multiple ways in which clinicians think, among the most widely accepted and useful methods of decision making is the theory of expected utility. Its use in decision making is called expected utility analysis. This technique requires the surgeon to list the potential benefits of any intervention and assign to each benefit both a probability for its occurrence and a specific assignment of numerical ranking to the expected utility or benefit of such an occurrence. Expected utility theory posits that the decision maker reaches a decision by summing the product of the expected outcome’s worth (utility) by the probability of that particular outcome’s occurrence. Summing the product of the various positive utilities, otherwise known as benefits (pain relief, independence in activities of daily living, return to employment, etc.) and subtracting from that the products of the negative utilities (risks such as death, pain, nerve injury, etc.) and their probabilities leaves an expected utility figure which then may be compared to the utility figure generated by other therapeutic choices. Rational decision making would lead the clinician to choose the therapy with the greatest overall utility.

This is in effect a risk/benefit analysis. An important assumption in this method is that utilities (or outcomes) can be expressed using a common scale. This has not been realistically accomplished for many orthopedic utilities. In business decision making such utilities are mainly economic factors, and utilities can be compared in common terms such as dollars. But, with medical decision making, where factors such as pain, various functional parameters, and ubiquitous “quality of life” must be taken into account are potentially more complex, and direct conversion to a standard utility rating may be much more difficult. Nonetheless, an approximation of this technique may be quite useful.

For any given procedure each potential benefit of the procedure can be assigned a utility factor. These can then be listed, with each assigned a probability. One can then sum the product of each utility by its probability, yielding a number representing the expected benefit of a particular intervention. The number derived from a similar sum of risk rankings multiplied by their individual probabilities can then be subtracted from the number calculated for the potential benefits of the procedure. Thus for a given procedure with potential benefits listed as 1, 2, 3 … X, and risks 1, 2, 3 … Y:

The resulting number may then be compared to figures generated from similar consideration of alternative procedures. Of course most of the risk and benefit “utilities” are subjective at this point in time, and there is little hard data on the probabilities of their occurrence in specific, unusual, or complex settings, hence the term subjective utilities analysis is usually employed. However, such analyses, even on an informal basis, can assist the surgeon in both the complex decision-making process and may also aid in communicating with the patient all of the potential risks and benefits involved in complex clinical settings as regards specific interventions. To make such complex decisions, the surgeon must accurately assess multiple patient-related factors as noted above, but must also adequately judge his/her own skills, experiences, and resources as regards any particular procedure.

As mentioned, many of the utilities in question are not associated with well-described or accurate probabilities, nor, are clinicians likely to use statistical analytic methods to make specific decisions for individual patients. Nonetheless, these models do yield insight into the complex decision-making process which may occasionally be required in assessing the applicability of THA in a given patient.

In part, this chapter attempts to review many of those issues facing the orthopedic surgeon and the patient when contemplating the performance of THA. The potential number of factors to be considered in this type of decision is relatively large, and makes up a challenging component of the surgical decision-making process. The remainder of this chapter will review those factors that may be considered appropriate in determining when THA surgery is or is not indicated.

Although THA is the operation of choice for severe arthritic hip disease in the vast majority of patients, it is clear that in several settings, other options (including further nonoperative treatment) may be more appropriate. Decision making
in this setting is dependent on many factors in addition to the underlying pathology, including the patient’s age and activity demands. There are several factors (or assumptions) regarding THA as an interventional choice that must be kept in mind when evaluating an individual for hip arthroplasty.

The first assumption is that arthroplasty is a time-limited operation. In general, an arthroplasty’s service life can be tied to complications related to fixation longevity, wear, or material failure (7). Although multiple series demonstrate relatively high component survival with a variety of fixation methods and component designs, even in relatively young and presumably active patients, it is difficult to imagine a young adult with a normal life span outliving a total hip implant. Thus age becomes an important factor in the decision to proceed with THA. Assuming no excessive comorbidities, and the presence of symptoms because of hip joint pathology amenable to arthroplasty, the older patient is typically a better candidate for arthroplasty, in that the operation and implant will most likely “outlive” the patient. The younger individual may well require multiple revision surgeries over their lifetime with an increased risk of deteriorating function.

Although it is difficult to outline specific age-based criteria, the pediatric and young adult patient clearly deserves an attempt at alternative treatment, such as arthrodesis or osteotomy. Long-term outcome studies of hip arthrodesis in young patients do reveal predictable longevity and overall improvements in quality of life. In one report of 53 patients with a minimum of 20 years follow-up, 78% of patients were satisfied with their results, and all patients were able to work (8). However, at long-term follow-up, up to 60% of hip arthrodesis patients suffer from significant low-back, ipsilateral knee, and contralateral hip pain (8,9).

It is important to consider, however if treatment such as arthrodesis will relieve symptoms sufficiently to postpone arthroplasty for a substantial period of time and not make subsequent conversion to a THA exceedingly complex or negatively affect the outcomes of a THA in the future. Furthermore, the risks and benefits of such nonarthroplasty options must be weighed against the risks and benefits of THA. It is hypothesized that modern prosthetic materials, including improved bearing surfaces may mitigate the risk of long-term failure of THA in young patients (10). However, while the medium-term results using modern materials are encouraging, (11,12) the long-term outcomes are still unknown.

Another assumption is that nonoperative treatment has failed to adequately relieve the patient’s symptomatology before proceeding with arthroplasty. This may include the use of assistive devices for ambulation, weight loss, systemic or local medications, and physiotherapy and activity modification. A concerted effort at nonsurgical therapy may be more reasonable in the younger patient than in the elderly where prolonged attempts are both time consuming, and rarely as effective in relieving symptoms and improving function as is THA. In some settings, the symptoms, physical findings, and x-ray changes are severe enough to warrant consideration of THA even if the patient has had no prior nonoperative treatment. However in most cases, particularly in the younger individual, it may be wiser to demonstrate to the patient that nonsurgical treatment will not relieve symptoms or improve function before recommending more aggressive treatment with the potential for more substantial risks and complications. The surgeon must keep in mind, however, that even nonoperative treatment is associated with risks which oftentimes are related to the regular use of anti-inflammatory medications including gastrointestinal bleeding along with the potential for hepatic, renal, and cardiac toxicity (13).

The level of patient activity and symptom severity are other important factors to consider in determining whether arthroplasty is indicated. Although pain is the most common complaint prior to surgical intervention, in many cases symptoms are activity related. In the patient whose symptoms are clearly amenable to activity modification, and in whom THA is not an ideal operation because of age, comorbidities, or other factors, the surgeon should opt for nonoperative treatment. An obvious and clear-cut example would be a young athlete whose hip pain only limits athletic activity. THA would not be expected to hold up to the rigors of athletic competition, so that such activity would be contraindicated following THA. If the individual has little or no symptoms with activity modification, then activity limitation would be a more reasonable course than proceeding with THA because of the potential serious long-term consequences of THA and the relatively small benefit obtained as the patient must abandon competitive athletic competition in either case.

Thus, behavior modification may play an important role in the treatment of hip disease. In attempting to understand a patient’s pain pattern, the clinician must decide whether a patient has realistically modified their activity to accommodate their damaged joint. If the patient is unwilling to alter their lifestyle to accommodate their degenerative joint, then the likelihood is that this patient will not alter their lifestyle to extend the life of a prosthetic joint. For example, as noted above, a patient unwilling to give up cutting sports or other joint-stressful pursuits which cause substantial discomfort is probably not having enough pain to warrant surgical intervention. On the other hand, it is unreasonable to ask a patient to modify their lifestyle to the point of extreme inactivity which may otherwise negatively affect their overall health and/or psyche. Thus, limitation in functional capacity is another important factor in determining the appropriateness of THA, and understanding the patient’s requirements for activities of daily living is essential in this determination. A patient’s ability to perform his or her job, do household tasks, and maintain personal hygiene can be used as measures of the effect of hip function on the patient’s lifestyle. Walking tolerance, defined as the length of time or distance one can walk without rest, can be an important benchmark in assessing the severity of disease and limitation of function. In general, if a patient cannot perform activities of daily living despite nonoperative treatment, his or her hip function has decreased to the point where THA may be indicated.

THA may also be indicated when a patient’s hip pain has progressed to the point that he or she suffers from significant pain at rest. Rest pain may progress to the point at which falling asleep or staying asleep may become difficult. Such sleeping difficulty may interfere with cognitive functioning and emotional stability. Many orthopedic surgeons consider rest pain—and particularly rest pain that interferes with sleep—as an important factor in determining a patient’s suitability for THA.

Actual decision making in the clinical setting of the young patient is usually far from straightforward, but often requires consideration of multiple factors before recommending THA. Other factors that influence the results and longevity of the THA would include weight and expected activity levels. Clearly the 18-year-old patient with severe multiarticular inflammatory arthritis and persistent adduction contracture interfering with hygiene and impeding any attempts at ambulation would be expected to stress a THA significantly less than a 30-year-old former professional football player who is 6½ ft tall, weighs 270 lb, and suffers from isolated posttraumatic arthritis of the hip. Increasing activity levels after THA—particularly high-impact sporting activities—have been correlated with increased risk of mechanical failure (14).

The goal of THA is to relieve pain and improve function. If these goals are kept in the forefront of a clinician’s mind, the task of deciding who would benefit from this procedure is usually not particularly difficult. However, as Charnley (5) intimated in the quotation above, there are no golden rules. The appropriateness of this procedure is a clinical decision-making process based on the natural history and severity of the disease, the expected result from intervention, and the risks of complications or failing to achieve the goals of surgery. Patient expectations and compliance are also critical variables and each case must be individualized.