CORR Insights®: Patients With Thumb-base Osteoarthritis Scheduled for Surgery Have More Symptoms, Worse Psychological Profile, and Higher Expectations Than Nonsurgical Counterparts: A Large Cohort Analysis

Where Are We Now?

Thumb carpometacarpal osteoarthritis (OA) generally occurs in patients older than 50 years of age, and it can cause pain and functional limitations, which impair the ability of patients to participate in daily activities [4]. Initial management of trapeziometacarpal OA generally is nonsurgical, and includes manual therapy and exercise. Many studies have demonstrated the efficacy of these non-surgical interventions in improving hand function and decreasing pain [2]. In some cases, however, these non-surgical options do not produce satisfactory results. One study [13] estimated that 15% of patients have surgery after an average of 2.2 years of non-operative treatment. Unsurprisingly, it appears that decreased pain over the course of non-surgical treatment lowers the likelihood that a patient will choose surgery for this condition [11].

While sociodemographic and clinical variables such as patient satisfaction, baseline pain, and function have been associated with 31% to 42% of differences in results of non-surgical treatment leading to surgery, not all factors correlating with increased likelihood of surgical conversion have been identified in thumb carpometacarpal OA [12]. In an effort to fill this gap in understanding, studies have identified psychological characteristics such as depression, negative illness perception, expectations, and pain catastrophizing as factors associated with greater likelihood of a patient choosing surgery in other types of OA [5, 6].

In the current study, Wouters and colleagues [14] performed a cross-sectional study to evaluate sociodemographic, clinical, and psychological characteristics and found that patients in the surgical group had worse clinical and psychological profiles than those in the non-surgical group. In a recent editorial, Ring and Leopold point out surgeons may play a role in these decisions. Knowing these factors could affect the way surgeons and patients determine an optimal course of treatment [10]. Specifically, a psychological survey of patients could be used as a screening tool to refer patients to mental health providers. This could help identify at risk patients for worse clinical and psychological outcomes and potentially change these outcomes by preoperative education and counseling.

Where Do We Need To Go?

Because the population is aging, and trapeziometacarpal OA increases in prevalence with aging—indeed, some say it is part of normal aging [1]—we need better tools to help us decide who will benefit from surgery for this condition. We also need to find ways to educate providers about the fact that the vast majority of patients with this condition should be managed without surgery.

It seems important to determine whether factors unrelated to the radiographic presence of trapeziometacarpal OA are associated with patients’ expectations of treatment. Patient expectation can be associated with outcomes in the form of disability related to OA but these expectations may be modifiable over time [5]. Some research suggests that having the condition in the dominant thumb and prior injury are associated with higher expectations from treatment while anxiety and depression were not [7], while another study assessing patients with persistent knee and hip OA pain have arrived at the opposite conclusion [3]. It is important to clarify this issue as modifiable variables should be given higher priority when making adjustments in approaching conversations about treatment options.

In an attempt to address these relationships and isolate these factors’ relative contributions, one study found decreased regional cerebral blood flow in patients with trapeziometacarpal OA [8]. This clarifies matters somewhat because it shows that different levels of brain activity are associated with different pain, anxiety, depression, and neuroticism scores, but as with any good research, it leaves some important questions unanswered, like which mechanisms are being affected and whether or not this creates a positive feedback loop for symptoms. Researchers found that pain scores and psychological traits (anxiety, depression, and neuroticism) accounted for 72.9%, respectively of variance in rCBF. Lower rCBF may be indicative of a decreased ability of modulating systems to inhibit noxious signals in cases of chronic pain [8]. These findings suggest that persistent joint pain caused by hand OA may trigger coping strategies that alter brain circuitry. Given that persistent pain despite non-surgical treatment is perhaps the most-important factor that causes patients to choose surgical treatment for this condition, it is important to answer questions regarding neural mechanisms of chronic pain in carpometacarpal OA of the thumb.

We know that patients with anxiety and depression who have orthopaedic procedures for knee, hip, and shoulder OA are more likely to have persistent pain or clinical dissatisfaction after elective orthopaedic surgery. The work of Wouters and colleagues [14] is one of only a few papers [3, 7, 9] that have sought to characterize the relationships between psychological distress and symptoms before or after surgery in patients with carpometacarpal OA of the thumb. We need greater clarity on this important set of topics.

How Do We Get There?

Given what we know, I suggest the following next steps to help identify what factors drive patients with trapeziometacarpal OA to choose surgery for their diagnosis: (1) Further longitudinal studies that evaluate the interaction of factors that have been shown to correlate with variance in non-surgical versus surgical populations in carpometacarpal OA of the thumb, such as anxiety, depression, pain, and patient expectations. Researchers should use correlation matrices and dimension-reduction measures to determine relationships among factors and isolate those factors with the greatest effect. (2) Long-term outcome studies that focus on pain, grip strength, and range of motion would also improve our understanding of the factors at play. I recommend all patients fill out a mini-DASH and short psychological profile such as the Hospital Anxiety and Depression Scale at each visit to help provide long-term longitudinal data. This will allow comparison of outcome scores among patients with differing psychological profiles. (3) Nerve physiology studies assessing local inflammatory markers and brain imaging, to identify the underlying mechanisms of persistent pain, as some preliminary work already has done [8]. These could elucidate potential coping strategies which may contribute to perceived pain, expectations for recovery, and psychological factors related to chronic OA pain. Findings from this kind of work may serve as a basis for a more direct assessment of the physiological aspects of the nervous system in patients with trapeziometacarpal OA.