Orthopedics

Feature Article 

Use of a Modified Rep Model in Primary Joint Arthroplasty: Lessons Learned

Morteza Meftah, MD; Vinay Hosuru Siddappa, MD; Nathan Johnson, MD; Peter B. White, DO, MS; Arthur Mack; Michael Skoller; Ira H. Kirschenbaum, MD

Abstract

Orthopedic implant device sales representatives (“reps”) can provide intraoperative guidance based on their product knowledge, as part of their many responsibilities. However, for experienced high-volume arthroplasty surgeons, a representative may not be required in the room for most primary total knee arthroplasty (TKA) procedures. The goal of this study was to describe the authors' experience with a modified rep model for primary TKA. Between January and December 2017, a total of 100 unilateral primary TKAs were performed with a modified rep model and compared with 100 primary TKAs that were performed before this protocol. The authors adopted 2 additional initiatives to institute this protocol safely: (1) improved education of operating room staff and allocation of responsibilities; and (2) reengineering of the existing surgical trays. No perioperative complications, including readmission, periprosthetic fracture, or infection, occurred in either group. In addition, no difference was found in mean length of stay between the modified rep and conventional cohorts (2.2 and 2.4 days, respectively; P=.49). Mean operating room time was less with the modified rep cohort (102.1 vs 117.8 minutes; P<.001), as was total instrument turnover time in the operating room (13.9 vs 29.7 minutes; P<.0001) and in central sterilization (59.4 vs 126.8 minutes; P<.001). No errors occurred with implant accuracy or trays, and there was no need to change the type of implant with the modified rep model, compared with 6% of trays requiring additional sterilization with the conventional model. The negotiated implant cost with the modified rep model was approximately $2000 less than that for the conventional group. This study found that the modified rep model for primary TKA is safe and has the potential for substantial cost savings. [Orthopedics. 2020;43(6):e538–e542.]

Abstract

Orthopedic implant device sales representatives (“reps”) can provide intraoperative guidance based on their product knowledge, as part of their many responsibilities. However, for experienced high-volume arthroplasty surgeons, a representative may not be required in the room for most primary total knee arthroplasty (TKA) procedures. The goal of this study was to describe the authors' experience with a modified rep model for primary TKA. Between January and December 2017, a total of 100 unilateral primary TKAs were performed with a modified rep model and compared with 100 primary TKAs that were performed before this protocol. The authors adopted 2 additional initiatives to institute this protocol safely: (1) improved education of operating room staff and allocation of responsibilities; and (2) reengineering of the existing surgical trays. No perioperative complications, including readmission, periprosthetic fracture, or infection, occurred in either group. In addition, no difference was found in mean length of stay between the modified rep and conventional cohorts (2.2 and 2.4 days, respectively; P=.49). Mean operating room time was less with the modified rep cohort (102.1 vs 117.8 minutes; P<.001), as was total instrument turnover time in the operating room (13.9 vs 29.7 minutes; P<.0001) and in central sterilization (59.4 vs 126.8 minutes; P<.001). No errors occurred with implant accuracy or trays, and there was no need to change the type of implant with the modified rep model, compared with 6% of trays requiring additional sterilization with the conventional model. The negotiated implant cost with the modified rep model was approximately $2000 less than that for the conventional group. This study found that the modified rep model for primary TKA is safe and has the potential for substantial cost savings. [Orthopedics. 2020;43(6):e538–e542.]

In recent years, health care reforms such as the Patient Protection and Affordable Care Act have highlighted the need for cost savings and cost transparency in various clinical settings.1 Total knee arthroplasty (TKA) is well recognized as a highly successful surgical intervention, and it accounts for the highest percentage of Medicare spending for inpatient procedures.2 Several alternative payment models, such as the Bundled Payments for Care Improvement and Comprehensive Care for Joint Replacement initiatives, have been developed to reduce costs and maintain a high quality of care.3 Preliminary studies of these initiatives showed promising results, largely as a result of streamlining perioperative processes and minimizing superfluous expenditures.4–7 The cost of TKA is multifactorial and varies significantly from institution to institution.8–10 Driving forces for the cost of TKA include personnel, duration of the operation, length of hospital stay, postoperative discharge disposition, and implant costs.11 Minimizing these expenditures can have profound effects on overall cost.

One method for reducing implant and supply costs is to customize the use of medical device sales representatives (“reps”) in the operating room. A modified rep model can help to reduce costs by eliminating the cost associated with having a vendor representative present for the procedure.12 However, because medical device representatives play an active role in the operating room,13 there is concern that their absence may be associated with an increased risk of complications. To the authors' knowledge, no studies have evaluated the efficacy and utility of TKA and the associated downstream effects without the presence of a medical device representative in the room. Therefore, the goal of this pilot study was to assess the effectiveness and safety of this modified rep model in primary TKA and the changes necessary to adopt the model at the authors' institution.

Materials and Methods

Between January and December 2017, a pilot study was launched to determine the efficacy of the modified rep model in primary TKA after institutional review board approval was obtained. A priori, it was determined that the authors would compare 100 unilateral primary TKAs performed with a modified rep model protocol with 100 primary TKAs performed before this protocol was instituted. Patients who underwent bilateral, revision, or complex (ie, biplanar deformity or ligamentous insufficiency) primary TKA were not included. Mean age of the entire cohort was 54.1±10.2 years, and mean body mass index was 35.1±5.3 kg/m2. There were no differences between the 2 cohorts in age, sex, or body mass index. The mean ages in the modified rep model and the conventional cohort were 55.1±8.1 years and 53.3±7.9 years, respectively (P=.1). There was no difference in sex between the two groups (P=.2). The mean body mass index was 32±5.9 kg/m2 in the modified rep model and 33.2±6.2 kg/m2 in the conventional cohort, which was not statistically significant (P=.16).

The modified rep model was introduced at the authors' institution in an effort to streamline the activities of the operating room staff, increase staff engagement, and reduce costs for uncomplicated primary TKA. This protocol was approved by the authors' institution under the conditions that the surgeons had access to a familiar backup revision system (MedTechDirect, Victor, New York) and that representatives would be available as needed for a difference in fee of $400.

To prepare for the transition, the authors realized that they needed to make two additional changes to the existing protocol to safely institute a modified rep model. First, they needed to divide up the tasks of a device representative and educate the existing operating room staff. The functions and responsibilities of a medical device representative were divided into 3 categories: (1) focusing on the availability of instruments, implants, and central sterile processing; (2) performing intra-operative management of the trays and maintaining familiarity with the instruments and techniques; and (3) verifying and opening the correct implants. These tasks were divided among existing operating room staff. Central sterilization coordinated with the implant manufacturing company for replenishment of implants. To improve their familiarity with implant systems, surgical technicians, central sterile processing staff, and operating room nurses received an additional 4 hours of training. Final verification of implants was assigned to the operating room circulating nurse.

Second, the authors further streamlined perioperative surgical processes by reengineering existing instrument trays to minimize unused space and reduce the number of trays used per case. Before the introduction of the modified rep model, a typical TKA procedure required 2 common knee instruments and 7 implant-specific conventionally wrapped trays. After the introduction of this protocol, the authors used only 1 common knee tray and 2 implant trays that were provided in rigid containers without wrapping (Figure 1). This step included identifying the essential instruments for arthroplasty cases (Figure 2). The implant and instruments were standardized to minimize intraoperative variability. The wrap-free trays were color coded, stackable, and customized.

Three custom trays without wrapping compared with traditional trays.

Figure 1:

Three custom trays without wrapping compared with traditional trays.

Standardized custom trays.

Figure 2:

Standardized custom trays.

The goal of this study was to assess the cost savings and safety of the modified rep model. The authors sought to identify perioperative complications or adverse outcomes that occurred as a result of the modified rep model, including errors with implant accuracy, the need to change the type of implant during the case (requiring augments, stems, or constrained designs), errors in opening implants, and the need for additional sterilization of trays or other items. Hospital length of stay, discharge disposition, and postoperative complications also were assessed. Postoperative outcomes were evaluated at a minimum of 3 months of follow-up to assess for readmission, periprosthetic fracture, and infection. Adjunctive measures of this protocol also were assessed via operating room time. The time required for turnover of instruments through central sterile processing and in the operating room also was calculated. The time needed to process the trays in central sterile processing, including sorting instruments, decontamination, washing and drying, and wrapping, was calculated for 20 cases in each cohort. In the operating room, the time needed for opening the tray, organizing the instruments, cleanup of instruments, and turnover was assessed.

All TKAs were performed by 2 fellowship-trained surgeons (M.M., I.H.K.) via the minimally invasive midvastus approach with identical surgical technique and with cemented components. Statistical analysis was performed with Stata software, version 14.0 (StataCorp, College Station, Texas). Continuous variables were assessed with mean and standard deviation, and categorical variables were assessed with frequency and percentage.

Results

No perioperative complications, such as errors with implant accuracy, changes in implant type, or the need for additional sterilization, occurred. Further, no readmissions, periprosthetic fractures, or infections occurred in either group. Mean length of stay was 2.2±0.5 days (range, 1–3 days) for the modified rep model cohort compared with 2.4±1.2 days (range, 1–6 days) for the conventional cohort. This difference was not statistically significant (P=.49). Most of the patients in both cohorts were discharged home (71% in the modified rep group vs 69% in the conventional group; P=.8). Mean operating room time for the modified rep group was significantly less (102.1±19.8 minutes) than that for the conventional cohort (117.8±17.8 minutes; P<.001).

In the modified rep cohort, no cases required sterilization of an additional tray and no cases were delayed. In comparison, in the conventional cohort, 6% of cases had an issue with holes in the wrap and sterile processing that required an additional tray or delay of the case. The difference was statistically significant (P=.03). Total mean instrument time was 13.9±2.25 minutes for the modified rep group and 29.7±3.0 minutes for the conventional group. Total mean instrument operating room time was less in the modified rep group (P<.001) for all facets, including opening, setup, and cleanup after the case (Table 1).

Operating Room and Central Sterilization Times

Table 1:

Operating Room and Central Sterilization Times

For the modified rep cohort, mean overall instrument turnover time for preparing 3 trays in central sterile processing was 59.4±4.4 minutes. This included 6±0.8 minutes for decontamination, 22.9±2.9 minutes for sorting, and 30.5±2.8 minutes for washing and drying (Table 1). Mean overall time in central sterilization was 126.8±4.18 minutes, including 13.8±1.1 minutes for decontamination, 36.4±3.2 minutes for sorting, and 62.2±1.9 minutes for washing and drying (2 rounds). Time in central sterilization was significantly less for total time as well as for decontamination, sorting, and washing and drying. The conventional cohort required an additional 14.5±1.6 minutes for wrapping the necessary trays.

Cost saving per case for each implant was approximately $2000, for a total savings of $200,000 during the course of this study. The time saving for central sterile processing was approximately 1 hour per case, for a total of 100 hours during this study. Also, turnover time for the modified rep group was on average 16 minutes less compared with the conventional group, which saved 90 minutes during an operating day of 2 rooms and 6 cases. The cost of wrap was $1.03 per sheet, or $7.21 per case, in the conventional group. With the 6% incidence of holes in the wrap during this study, the authors found a total savings of $765 in the modified rep group.

Discussion

Although TKA is well recognized as a highly successful and cost-effective procedure,14 cost remains a prevalent issue.1 Cost in orthopedics is difficult to quantify because it is multifactorial; however, several key contributing factors are staff overhead, duration of the operation, and implants.11 A proposed pathway is to reduce some of these costs in a modified rep model. This method requires reengineering the process and flow of the operating room and allows for optimizing the utility of representatives in other critical portions of the episode of surgical care.12 Although many representatives play an active role in the surgical process, their usefulness for certain duties in uncomplicated primary TKA may not be as great in a high-volume practice with a single implant company. This pilot trial found that the use of a modified rep model was associated with no increase in complications or adverse outcomes and was associated with substantial cost savings. In addition, the authors found that the changes they made to their instrument trays with the modified rep model resulted in significantly improved operating room turnover time and central sterile processing time for uncomplicated primary TKA.

This study had several limitations. First, it was a pilot study performed with 2 consecutive cohorts of 100 TKAs. However, statistical significance was reached in the authors' measured outcomes. Second, this study was performed at a single institution with the appropriate resources in place. However, because this is not the case in all institutions, these findings should be generalized with caution. Third, because all patients underwent uncomplicated primary TKA, these data cannot be extrapolated to patients undergoing complicated, bilateral, or revision TKA. Fourth, the nature of the study made it difficult to assess the learning curve associated with this protocol. In the authors' experience, approximately 10 cases were needed for the institution to adjust to this new protocol.

Many medical device representatives are trained in the nuances of their implant systems so that they can provide intraoperative counseling when necessary. A web-based survey reported that up to 88% of medical device representatives have reported being actively involved in a surgery.13 For uncomplicated primary TKA, the additional input may not be necessary, especially for more experienced high-volume arthroplasty surgeons. The current authors found that absence of a medical device representative was not associated with intra-operative or postoperative complications. Although some of these findings may reflect the limited sample and specific patient selection, this study shows that medical device representatives are not necessary for every TKA case. However, patient selection is an integral component of a modified rep model, and the presence of a representative is beneficial in complex primary or revision cases. For a modified rep model to be successful, it is important to be prepared for any situation that may arise intraoperatively. The use of a system that has universal femoral and tibial implants that can accommodate a constrained insert is essential to avoid unanticipated issues with ligament balance. In addition, the use of a familiar revision implant system as well as access to cables and wires would reduce the chance of intraoperative issues with fractures.

Eliminating the presence of medical device representatives in the operating room through a modified rep model allowed for negotiation of a significantly reduced rate for implants. Negotiating implant price is not a new concept.15,16 Bosco et al16 used price ceiling negotiation with different vendors that resulted in an average net decrease of 22% to 33%. However, to the current authors' knowledge, no studies have reported on negotiating the value of the presence of a representative during surgery. The authors' negotiation led to a reduction of $2000 per implant. This is substantially less than the cost of an implant in the early 1990s.17 Because the authors' institution has the implant cost as part of its bundled payment, this reduction in price can have profound effects on cost per episode of care.

In the authors' experience, the key to the modified rep model is developing the appropriate infrastructure, including appropriate training of operating room staff and reengineering of instrument trays. With these changes, this protocol was associated with reduced operating room time and less time for decontamination of trays, instrument setup, and overall instrument turnover. These effects likely reflect improved training of operating room staff and a streamlined perioperative process (ie, fewer instruments) as opposed to absence of the representative. Although these changes were made as a result of the change to a modified rep model, they likely can be made without the modified rep model with similar benefits. Regardless, saving time in the operating room and central sterile processing can lead to meaningful cost savings that are specific to each institution.18–21 It is critical to note an important limitation of this study: the authors focused only on the use of a representative in the operating room in “cherry-picked” straightforward cases at the time of the procedure, and not the many other valuable responsibilities during the longitudinal episode of care in joint replacement. It is essential to understand that the representative have tremendous value in the success of arthroplasty cases, and their essential contributions can be used more effectively with the described method.

Conclusion

The authors found that a modified rep model for TKA was safe and had the potential to reduce costs. Reengineering trays, redesigning the work flow, and reallocating responsibilities were essential components of the goal of achieving a successful outcome with the modified rep model. Preparation for the transition, proper patient selection, standardization of trays and implants, and distribution of responsibilities among operating room circulating nurses, technicians, and the surgeon are essential for success. The downstream effects of the modified rep model, such as modification of trays, can lead to substantial time and cost savings in the operating room and central sterile processing.

References

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Operating Room and Central Sterilization Times

ParameterMean±SD (Range) Time, minutes:secondsP

Modified Rep ModelConventional Cohort
Operating room
  Opening, unwrapping, checking, and discarding wrap2:59±0:20 (2:17–3:33)5:52±0:18 (5:15±6:27).0001
  Setting up and organizing instruments5:52±2:05 (3:04–7:58)9:25±0:25 (8:47–10:12).0001
  Placing the instruments back onto the tray5:01±0:24 (4:03–5:56)14:50±2:13 (5:37–16:15).0001
  Total time13:52±2:15 (9:31–16:45)29:40±3:02 (21:06–32:30).0001
Central sterile
  Decontamination5:57±0:50 (5:13–7:22)13:48±1:03 (12:09–15:56).0001
  Sorting instruments22:54±2:51 (18:12–28:11)36:21±3:09 (33:02–45:46).0001
  Washing and drying30:30±2:46 (27:00–32:00)1:02±1:59 (1:00–1:05).0001
  Wrapping trays014:30±1:36 (12:30–18:42).0001
  Total time59:21±3:19 (55:11–1:07)2:06±4:11 (2:01–2:15).0001
  Incidence of holes requiring rewrapping0%6%.0289
Authors

The authors are from the Department of Orthopedic Surgery (MM), NYU Langone Orthopedic Hospital, New York; Bronx Lebanon Hospital Center (VHS, NJ, AM, MS, IHK), New York; and Northwell Health Plainview Hospital (PBW), Plainview, New York.

The authors have no relevant financial relationships to disclose.

Correspondence should be addressed to: Morteza Meftah, MD, Department of Orthopedic Surgery, NYU Langone Orthopedic Hospital, 301 E 17th St. 15th Fl, New York, NY 10003 ( Morteza.Meftah@nyulangone.org).

Received: May 04, 2019
Accepted: October 18, 2019
Posted Online: September 03, 2020

10.3928/01477447-20200827-07

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