Background: This systematic review assesses the current literature and reviews the clinical outcomes of treatment for sagittal band injuries and extensor tendon instability. Materials: A systematic search of MEDLINE, EMBASE, and the Cochrane databases was performed for English-language articles on the treatment of nonrheumatoid adult sagittal band injuries between 1969 and 2019. Two independent reviewers were involved in screening, data extraction, and critical appraisal. The level of evidence was assigned using the Sackett scale, and the methodological quality of the studies was evaluated using the Structured Effectiveness Quality Evaluation Scale (SEQES). Outcome measures were persistent pain, extensor lag, and recurrent tendon subluxation. Results: In all, 1653 abstracts were identified, with 43 articles reviewed in full text and 17 articles (429 treated digits) included in the final systematic review. There were 10 studies on surgical management, 3 on nonoperative management, and 4 on both. There were 4 retrospective case series and 13 retrospective case reports (Sackett level 4) with an average SEQES score of 15 (low quality). Studies on nonoperative management had on average more digits per study and higher SEQES scores (n = 27.7, SEQES = 19) compared with studies on surgical management (n = 11.8, SEQES = 13.8). Variability in reported outcome measures precluded meta-analysis. Conclusion: Qualitative synthesis of available literature suggests that acute sagittal band injuries can be successfully treated by splinting the injured digit in neutral or hyperextension. Patients with chronic injuries or those failing nonoperative management may benefit from surgical exploration. A lack of consistent outcome measures precluded comparison of surgical techniques.