Conservative Outcomes of Subtalar Dislocation: A Systematic Review and Meta-Analysis of the Current Literature

Subtalar dislocation is a rare injury accounting for 1%-2% of all dislocations. Although prompt closed reduction is the accepted initial treatment, optimal conservative management protocols remain unclear, and no prior systematic review has synthesised outcomes of purely conservatively managed cases across both medial and lateral dislocations. This review aims to systematically assess the rates of post-traumatic osteoarthritis, functional outcomes, subtalar stiffness, avascular necrosis, and need for subsequent surgery following conservative management of acute isolated subtalar dislocations.

A systematic review was conducted according to the PRISMA 2020 guidelines. PubMed, Cochrane Library, CINAHL, Web of Science and OVID were searched for studies reporting outcomes of conservatively managed acute isolated subtalar dislocations. Eligible studies included case series and cohort studies reporting radiographic or functional outcomes following closed reduction and immobilisation. Risk of bias was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for case series. Radiographic post-traumatic arthritis rates were pooled using random-effects meta-analysis; functional and other outcomes were synthesised narratively. Given the clinical heterogeneity of the included studies, this review adopted an exploratory descriptive framework.

Ten studies comprising 201 feet were included. All cases were case series (9 retrospective, 1 prospective) with mean follow-up ranging from 12 to 122 months. Medial dislocations predominated (75%-80%). Pooled radiographic post-traumatic arthritis occurred in 36% (95% CI: 18%-53%; I² = 43%), though many patients remained functionally well despite structural changes. Functional outcomes were generally favourable for closed medial injuries, with the highest scores achieved using early mobilisation protocols. Reduced subtalar range of motion was common, affecting 42.8%-76.6% of patients where reported. Avascular necrosis was rare (0.5%) and subsequent subtalar fusion was required in only 4.2% of cases. Lateral dislocations had significantly worse outcomes than medial injuries.

Radiographic post-traumatic arthritis is common following conservative management of subtalar dislocations (36%) but was frequently not associated with functional impairment; favourable functional outcomes were achieved for closed medial injuries, although symptom severity was inconsistently reported across studies. Avascular necrosis is rare. Lateral dislocations consistently have poorer prognoses.