A method for preparing a backup kit for a plurality of patient-specific arthroplasty procedures scheduled at the same medical facility includes providing a database with data from completed arthroplasty procedures using patient-specific arthroplasty kits. The database includes comparisons between preoperatively planned implant size and intraoperatively implanted implant size. The method includes determining a statistically expected implant size deviation from a planned implant size for each implant included in a plurality of patient-specific arthroplasty kits prepared for a shipment to the medical facility using the database. A backup kit of backup implants is assembled for the shipment. The number and size of the backup implants is determined from the statistically expected implant size deviations.