Severe glenoid bone loss can make reverse shoulder arthroplasty technically demanding because standard baseplates may not achieve reliable fixation. This review examined patient-specific and custom implant strategies designed to address challenging glenoid deficiency. The concept is based on three-dimensional reconstruction from CT imaging, allowing the implant or instrumentation to be matched to the patient's individual anatomy. The available literature suggests promising short-term clinical and radiographic results, especially in cases where conventional eccentric reaming, bone grafting or standard augmented components may be insufficient. However, the evidence remains relatively immature, with many reports consisting of small case series and limited long-term follow-up. That distinction matters when counselling patients and evaluating the role of these technologies in routine practice. Patient-specific implants are better viewed as a problem-solving option for complex primary or revision arthroplasty rather than a universal replacement for established techniques. Their value lies in improving fixation options when bone stock is severely compromised. Careful preoperative planning, accurate CT-based templating and an understanding of the limitations of custom manufacturing remain essential. The article highlights how digital planning and additive manufacturing are moving personalised orthopaedics from concept toward practical use.