Sensitivity analyses revealed that the optimal decision making strategy was very sensitive to small changes in several variables. Nonoperative treatment becomes the preferred strategy when the utility value for uncomplicated surgery falls below 8.04 (Figure 2), when the utility for healing with nonoperative treatment rises above 8.49 (Figure 3), when the likelihood of healing with nonoperative treatment rises above 82% (Figure 4), or when the probability of healing after surgery falls below 92% (Figure 5). Nonoperative treatment is also favored when the probability of minor complication with surgery is above 17% (Figure 6) and when utility for a successfully treated nonunion is higher than 6.9 (Figure 7).
Discussion
Optimal management of a metadiaphyseal fracture of the fifth metatarsal (Jones fracture) remains controversial. The decision between initial operative or nonoperative treatment lends itself to expected-value decision analysis because of well-defined treatment options and relatively discrete outcomes. The principal advantages of nonoperative treatment are that it allows the patient to avoid the risks and discomfort of surgery, and the principal advantages of operative treatment are that it maximizes the chance of fracture union and may accelerate functional recovery.
Our decision analysis determined that operative fixation is the optimal decision path, given the outcome probabilities derived from the literature and the utilities obtained from surveys. This finding is in accordance with several expert opinions in foot and ankle fracture surgery.17,18 However, the expected values of the operative and nonoperative treatment strategies differed by only 0.3 on a 10-point scale. Such similar expected values in our model are not surprising given the controversy surrounding clinical decision making in the treatment of these fractures.19
In addition, our analysis identified the important variables in the decision-making process. Patients averse to surgery, patients not averse to successful nonoperative treatment, and patients who view successful nonunion surgery after initial nonoperative treatment as a relatively positive outcome may be best treated nonoperatively. These findings emphasize the importance of patient preferences and shared decision-making. Higher rates of healing with nonoperative treatment, lower rates of healing with surgery, and higher complication rates with surgery also favor nonoperative management. It would therefore be valuable to identify risk factors for nonunion with nonoperative treatment and to identify the technical details of surgery that maximize rates of healing and minimize the risk of complications.
The limitations of decision analysis involve the methods by which probabilities and utilities are obtained. In general, the most accurate, stable, and robust estimates of outcome probabilities are derived from a meta-analytic synthesis of randomized clinical trials, the highest level of clinical evidence. In our model, data were extracted primarily from level IV studies; only 1 level III study20 and 1 level II study21 were available for analysis. Thus, as is the case with many foot and ankle disorders22, the information on treatment of Jones fractures is very limited in its level of clinical evidence.
Determination of outcome utility also has limitations. Utility is a subjective value that an individual places on a specific outcome. This can be very difficult to quantify. In general, the most robust estimates of patient-derived utilities are derived from complex qualitative methods, such as the standard reference gamble or time trade-offs, in which patients are asked to gamble or choose between health states usually referenced to death. In this study, we determined patient-derived utility values from a direct scaling method using a Likert scale because of the complexity of the standard reference gamble and the difficulty of referencing to death for metatarsal fracture. Although use of a direct scale to determine utility values is less rigorous than the standard reference gamble, this technique has been corroborated methodologically,23 is advantageous in terms of feasibility and reliability,24 and has been successfully used in other orthopedic decision analysis models.12,25,26 In our estimation, generally active patients without a history of foot pathology constituted a sample of convenience but also were representative of individuals at risk for Jones fracture. Although specific scenarios were presented, the patients who completed the questionnaire may not have had deep insights into the subtleties and implications of the various disease states and treatments. Regardless of how outcome probabilities and utilities are determined, they are considered point estimates in decision analysis, and sensitivity analyses are therefore performed to assess how decision making changes over a range of values.
Conclusion
The results of this study may help optimize the process of deciding between operative and nonoperative treatment for Jones fracture. For a given patient, the optimal strategy depends not only on the probabilities of the various outcomes but also on personal preference. Thus, there may not be one right answer for all patients. Patients who value a higher chance of fracture healing with initial treatment or an earlier return to sports are best treated operatively, whereas patients who are risk-averse and place a high value on fracture healing without surgery should be managed nonoperatively. We therefore advocate a model of shared medical decision-making in which the physician and the patient are jointly involved, considering both outcome probabilities and patient preferences. Ongoing research efforts should focus on predictors of nonunion with nonoperative treatment.