Although uncommon, neglected developmental dysplasia of the hip (DDH) poses a technically demanding problem for treating surgeons. Due to the congenital malformation of the native hip joint and distortion of the surrounding soft tissue, addressing limb-length discrepancy is intricate. Despite detailed planning and meticulous soft tissue handling, complications can be difficult to avoid in these patients even under experienced hands. In this case report, we present a 73-year-old lady with neglected DDH who had undergone initial total hip arthroplasty and subsequent revision surgery that failed due to aseptic loosening. Due to limited length in the distal femur, we used a telescoping allograft prosthetic composite (APC) to provide adequate length to the native distal femur during revision with proximal femur fixation. This technique can help avoid the need for total femur replacement (TFR) surgery, which is more invasive and may require tibia replacement.