What Factors Are Associated With Outcomes Scores After Surgical Treatment Of Ankle Fractures With a Posterior Malleolar Fragment?

Background: Psychosocial factors, such as depression and catastrophic thinking, might account for more disability after various orthopaedic trauma pathologies than range of motion and other impairments. However, little is known about the influence of psychosocial aspects of illness on long-term symptoms and limitations of patients with rotational-type ankle fractures, including a posterior malleolar fragment. Knowledge of the psychosocial factors associated with long-term outcome after operative treatment of trimalleolar ankle fractures might improve recovery.

Questions/purposes: (1) Which factors related to patient demographics, physical exam, diagnosis, or psychological well-being (in particular, depression), if any, are associated with better or worse scores on validated lower-extremity outcomes instruments after surgical treatment for rotational ankle fractures (including a posterior malleolar fragment) at long-term followup?

Methods: Between 1974 and 2002, 423 patients underwent open reduction internal fixation for rotational ankle fractures with posterior malleolar fragments according to the basic principles of the AO (Arbeitsgemeinshaft für Osteosynthesfragen). Minimum followup for inclusion here was 10 years (range, 12.5-39.4 years). When posterior malleolar fragments involved more than 25% of the articular surface as assessed on plain lateral radiographs, the fracture was generally fixed with AP or posterior-anterior (PA) screws. Of those treated surgically during the period in question, 319 were lost to followup, had too much missing data to include, or declined to participate in this study (or could not because of reasons of mental illness) (68%), leaving 104 (32%) for analysis in this retrospective study. Independent observers not involved in patient care measured disability using the patient-based Foot and Ankle Ability Measure questionnaire and using the subscale Activities in Daily Living (ADL) and pain score of the Foot and Ankle Outcome Score. General physical and mental health status was evaluated using the SF-36. Depressive symptoms were measured with the Center for Epidemiologic Studies-Depression scale score (range, 0-60 points). A score above 16 indicated a depressive disorder. Misinterpretation or overinterpretation of nociception was measured with the Pain Catastrophizing Scale score. Scores above 13.9 were considered abnormal. Statistical analyses included uni- and multivariate regression analysis. In general, patients in this series reported good to excellent outcomes; the mean ± SD scores were 91 ± 15 for Foot and Ankle Ability Measure, 93 ± 16 for Foot and Ankle Outcome Score (ADL), 91 ± 15 for Foot and Ankle Outcome Score (pain), 49 ± 9 for SF-36 mental component score, and 52 ± 9 for SF-36 physical component score.

Results: Implant removal (β = -8.199, p < 0.01) was associated with worse Foot and Ankle Ability Measure scores. Better flexion/extension arc (β = 0.445, p < 0.01) and lower Center for Epidemiologic Studies-Depression scores (β = -0.527, p < 0.01) were associated with better Foot and Ankle Ability Measure scores. Osteoarthritis (β = -4.823, p < 0.01) was associated with worse Foot and Ankle Outcome Score (pain) scores. Better flexion/extension arc (β = 0.454, p < 0.01) and lower Center for Epidemiologic Studies-Depression scores (β = -0.596, p < 0.01) were associated with better Foot and Ankle Outcome Score (pain) scores. Better flexion/extension arc (β = -0.431, p < 0.01) and lower Center for Epidemiologic Studies-Depression scores (β = -0.557, p < 0.01) were associated with better Foot and Ankle Outcome Score (ADL) scores. Finally, we found that a better inversion/eversion arc (β = 0.122, p = 0.024) was associated with better SF-36 physical component score and that a lower Center for Epidemiologic Studies-Depression score (β = -0.567, p < 0.01) was associated with better SF-36 mental component score.

Conclusions: Psychological aspects of recovery from musculoskeletal injury merit greater attention, perhaps even over objective, unmodifiable predictors. A mean of 24 years after surgical treatment of ankle fractures with a posterior malleolar fragment, patient-reported outcome measures have little to do with pathophysiology; they mostly reflect impairment and depression symptoms. Further research is needed to determine whether early indentification and treatment of at-risk patients based on psychosocial factors can improve long-term outcomes.

Level Of Evidence: Level III, therapeutic study.