Posterior Lumbar Spinal Fusion. Regarding variance by case volume and years in surgical practice, we found no significant difference for any variable analyzed: percentage of cases with waste (volume, P = .36; years in surgical practice, P = .22), percentage of total implant cost wasted (volume, P = .33; years in surgical practice, P = .41), cost of waste per case (volume, P = .34; years in practice, P = .15).
Discussion
The steadily increasing demand for orthopedic surgeries and declining rates of reimbursement by Medicare and other insurance providers have led many hospitals to look for ways to control the cost of these surgeries. Reducing operating room costs, lowering implant prices, and shortening hospital stays have all proved successful.6,15,20,23 One area that has not been thoroughly explored is the cost burden of wasted implants. Our findings suggest implant waste contributes significantly to the cost of orthopedic surgeries.
One weakness of this study is that its data, though encompassing all orthopedic subspecialties and procedures, come from a single teaching institution and therefore are less representative of all orthopedic departments across the United States. However, the findings are useful in that the analysis was performed across multiple specialties at a high-volume institution and may be applied to similar institutions. Another weakness of this study is that the data cover only 1 year. Collecting data over a longer period could improve the magnitude and power of the analysis. Nonetheless, 1 year of data is a good starting point in identifying the issues and guiding the initiation of measures to address them. Last, we did not explore the reason for each instance of waste during the period reviewed. Knowing the reason for implant waste would be helpful in developing strategies to reduce implant waste.
Our study results showed that, in 1 year, implant waste occurred in 1.8% of procedures that required an implant—representing a loss of $634,000. Other studies have quantified implant waste for selected procedures or single departments, but to our knowledge none has quantified implant waste for an entire orthopedic department or hospital. It is therefore difficult to compare our institutional results with other results. For instance, definitions of waste differ. A study that found waste in 20% of spine surgery cases22 included all intraoperative waste, whereas our 11% of spine cases were implant waste only. Similarly, though rates of implant waste in trauma cases differed significantly between a multi-institution study by Zywiel and colleagues24 (0.6%) and our institution (30%), their study excluded arthroplasty cases from the trauma subset and reported implant waste for a single vendor, whereas we included arthroplasty cases and a wide array of implant vendors. In addition, costs cannot be directly compared because, in our study, implants wasted may have differed. Although the Trauma division had the highest incidence of waste (30%) in our analysis, it did not have the highest waste-related costs. Instead, the Adult Reconstruction division, with waste in 8% of cases, had the highest waste cost, $214,869. The cost difference is certainly the result of the difference in type of implants wasted. The implants most commonly wasted in the Trauma division were screws, which cost between $17 and $150; a single femoral stem, though wasted less often, cost significantly more, $2000 to $6000.
Our results showed a combined implant waste incidence of 6.8% for primary THA and primary TKA cases over the year. In their multi-institution study, Zywiel and colleagues19 reported a combined incidence of implant waste in 2% of THA and TKA cases. The difference is that Zywiel and colleagues19 reported data from a single implant vendor and included revision surgeries, hip hemiarthroplasties, and unicondylar knee arthroplasties. Another study reported implant waste in 5.7% of all TKA cases but did not specify whether revision or unicondylar arthroplasties were included.25 For lumbar spinal fusion, we found an implant waste incidence of 14%. Given the lack of studies in this area, we cannot make a comparison of results.
To our knowledge, there has been no other study of the effects of case volume and years in surgical practice on implant waste. Our analysis showed that waste incidence was not related to surgeon case volume but was related to years in surgical practice. Incidence of waste was significantly lower among surgeons practicing 20 years or more than among surgeons practicing fewer than 10 years. The difference may be a reflection that case volume during a single year is not totally indicative of a surgeon’s lifetime case volume. For example, several surgeons with many years of experience and a significant lifetime case volume had an annual case volume in the lower 25% of the department because they were approaching retirement or had only recently joined the institution. More rigorous prospective studies are needed to further understand this relationship.