In 2019 it was identified that the Alvarado Knee Positioner could house residual debris from surgery. Bodily fluids would accumulate in crevasses within the device where it was difficult if not impossible to remove...
Patient positioning equipment specifically designed for knee surgery has been available for decades...
Cleaning and sterilization guidelines from organizations such as AORN clearly identify the need to have components clean before they can be sterilized..
The U.S. Food and Drug Administration (FDA) is providing recommendations for health care providers considering using the Total Hip System, including resurfacing implants, manufactured by Synovo Production, Inc. (Synovo) and for patients who may have received certain implants used in the Synovo Total Hip System after 2019. Three components of the system, the Femoral Resurfacing Cup, the Acetabular Fixation Cup, and the Acetabular Bearing, have been significantly modified from the devices that were cleared by the FDA. The safety and effectiveness of the Synovo Total Hip System, including the Femoral Resurfacing Cup, the Acetabular Fixation Cup, and the Acetabular Bearing, have not been established. The Synovo Total Hip System is also referred to as the Total Hip Replacement System, and also as Synovo Preserve and Endotec BP.
Full statement from the FDA is available here.
The Alvarado Knee Positioner which has been recently recalled by Zimmer Biomet was one of the most widely used knee positioners in North America. The system excelled in simplicity both in setup and application. Unfortunately, there existed some significant flaws in the Alvarado design and manufacturing that led to the recall of all systems ever produced.
As replacement knee positioners are reviewed, facilities have an opportunity to make significant improvements in the functionality, durability, and overall quality of their positioning equipment for total knee arthroplasty.
In looking at some of the available alternatives, it makes sense to start by reviewing some of the Alvarado shortcomings that have been shared by past users. In addition to the inability to properly clean the system components, which ultimately led to the FDA reported recall, there are concerns about functionality and durability.
The Alvarado positioner has limited flexion adjustment. Measurements of the system show that there is only about 220mm (9 inches) of total flexion range. This is nearly always insufficient to give reasonable extension and hyper flexion without repositioning the base, and it was shared that often times base was moved, or not used during portions of the procedure. This is complicated by the fact that the clamping system violated the sterile field and often damaged the surgical drapes where it was clamped.
A second concern to consider is the stability of the overall system. There were two common versions in use. One used a stop block under the drape that the rail base would simply butt up against. A second version used a single down arm that was riveted to the rail base plate. Both versions led to instability that staff would often add support by adding tape and positioning bags under the drape.
There were also multiple reports of poor durability of the foot holder itself. The boot portion was constructed of a thin gauge aluminum with a lattice of perforations. This lattice section would break after being flexed and would leave sharp edges against the patient’s leg. The foot holder would then need to be taken out of service and fixed or replaced.
This review is of 5 of the best alternative products and takes a look at some of the pros and cons. Many of the findings were shared by existing users of these products, others were made by handling and setting up the systems directly.
All of these knee positioning systems are a significant step up from the Alvarado, and all of them gave an increase in flexion range. Most of them used a rail, or modified rail system for adjustment. The Ladderloc system utilizes a notched twin rail very similar to the Alvarado, but gives twice the flexion range.
When considering durability, nearly all of them are a major improvement, with the exception of the TKR Positioner. This positioner has a significant wear point at the boot mounting ball which can cause complete failure. It also has the weakest foot holder material which can be bent, resulting in sharp edges. It should be noted that the De Mayo positioner has a similar ball mechanism, The design has added multiple additional components to reduce catastrophic failure, but the result is a much more difficult product to clean and maintain.
Stability during use was not a significant factor according to our consulting facilities. The De Mayo, the Stulberg, and the TKR all use a center mount design, the Ladderloc and Solorail use a mounting base that has two down arms that have wider spacing. The mounting system for the TKR and the De Mayo both use a clamp that mounts over the drape, thereby extending outside of, and violating the sterile field. The other three systems mount via a base underneath the drape.
The Stulberg positioner seemed unnecessarily complex, and the De Mayo was only slightly better, requiring multiple steps to even remove the foot holder from the adjustment block. The others were nearly as simple as the Alvarado was to use.
Readdressing the reason for the Alvarado system recall, residual organic debris after cleaning. Two of these systems, the De Mayo and the Stulberg, were found to have hidden hinge and connection points that cannot be disassembled for cleaning. These locations could easily hide residual surgical debris, resulting in issues similar to those in the Alvarado.
Patient positioning equipment specifically designed for knee surgery has been available for decades. In fact, the Alvarado Knee Positioner was patented by Zimmer over 40 years ago. The positioners come in a vast range of technology and capability. Most are adjustable, although the approach may differ between hooking into notches, sliding on a rail, or even dropping into holes. The commonality is that they all, or nearly all, utilize a “boot” component to receive the patient’s foot. By use of a foot holder, the positioners add stability not only in flexion angle, but laterally as well. Dependent on the particular system, this can reduce the number of hands on the patient, and number personnel in the sterile field. The Alvarado positioner truly paved the way for advances in stability of the patient’s leg, and today systems are available that allow adjustment through the full flexion range as will as pivot adjustment and distraction. Some systems even have accessories available for adjustable lateral thigh supports. The positioners All of this leads to a more stable surgical platform, a better respect for the sterile field, and improved patient protection.
In 2019 it was identified that the Alvarado Knee Positioner could house residual debris from surgery. Bodily fluids would accumulate in crevasses within the device where it was difficult if not impossible to remove. Zimmer stepped up and issued a recall for all devices ever manufactured. See the Alvarado recall notice and FDA documents here. Unfortunately, there are other nearly identical systems in use that have not been recalled. All functional Alvarado systems should be examined for open cracks and crevasses that could house organic debris, and removed from service.
Cleaning and sterilization guidelines from organizations such as AORN clearly identify the need to have components lean before they can be sterilized. Accumulation of organic debris from prior surgical procedures represents a major breakdown in sterile processing and infection control. Many of the recent recalls through the FDA, such as the rash of endoscope cleaning recalls, involve surgical equipment that was not or could not be cleaned properly, and has led to postoperative infections. The Alvarado Knee Positioners housed a substantial amount of debris which led to the 2019 recall. Unfortunately, the Alvarado went over 40 years before the debris issue was identified. Sterile processing personnel should be trained to recognize the potential for issues on any equipment that they handle.
This video was recorded in an effort to demonstrate to facilities the concern with unsealed connection points on medical devices. It shows very clearly the issues with partial welds, and areas that can only be rinsed. It is increasingly obvious that hidden surfaces which cannot be seen and wiped will accumulate organic debris, and create a starting point for infection and postoperative complications.
It is recommended for proper patient protection, that a pad specifically designed for your foot holder be used with all positioning devices. These pads are delivered in a sterile pouch, and often include a coadhesive wrap to secure the patient to the foot holder. Periodically, a facility will attempt to save money by avoiding the use of disposable pads, only to find that the cost of the reusable towels, the cleaning process, and the additional time required to apply them often exceeds the price of the appropriate pad, let alone the potential cost of a pressure injury. It should be noted that not all pads are created equal, and some will compress to a point that they do very little to protect the patient.
Resources related to disinfection and sterilization for health care settings.
Guideline for Disinfection and Sterilization in Healthcare Facilities (2008)
ECRI is a global, independent authority on healthcare technology and safety.
AST developed the Standards of Practice to support healthcare facilities in the reinforcement of best practices, related to positioning the surgical patient on the OR table.
Guideline for Disinfection and Sterilization in Healthcare Facilities (2008)
Match Grade Medical takes a look inside a recalled Alvarado foot holder to reveal contamination.
Becker's Healthcare is the go-to source for healthcare decision-makers and one of the fastest growing media platforms in the industry.
This webinar replay provides clarification of the survey process related to disinfection and sterilization.
The FDA posts summaries of information about the most serious medical device recalls.
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