Background The calcaneal dorsal closing wedge osteotomy, otherwise known as the Zadek or Keck and Kelly osteotomy, is used to treat insertional Achilles tendinopathy. The purpose of this study is to investigate the clinical outcomes affiliated with the Zadek technique for insertional Achilles tendinopathy (IAT) as reported in the literature. Methods An English literature search on PubMed was performed yielding 8 level IV retrospective case series. Results The weighted mean of preoperative and postoperative Victorian Institute of Sports Assessment—Achilles Questionnaire (VISA-A) scores was 52.7 and 87.8, respectively. The weighted mean of preoperative and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) scores was 56.3 and 92.9, respectively. Majority of the reported complications were minor events, including symptomatic hardware (2.8%; n = 7/247), sural nerve paresthesia (2%; n = 5/247), and superficial infection (3.2%; n = 8/247). There was 1 reported event of hardware failure resulting in re-operation. Deep vein thrombosis occurred at a rate of 0.8% (n = 2/247), complex regional pain syndrome at 0.4% (n = 1/247) and nonunion at a rate of 1.2% (n = 3/247). Conclusion The Zadek osteotomy is a viable option for insertional Achilles tendinopathy based on significantly improved outcome measures and minor complication rates. Level of Evidence: 4