August 26, 2016
The questions below aren’t asked often, but we get them often enough that we think it’s a good idea to share them with you. Maybe you’ve heard some of these yourself, or wondered about them but didn’t get around to asking.
Q1. Demo of the SuperCable last week prompted a surgeon to ask me: “Because it is a double loop cerclage, what guarantee is there that the cable tension is equal both sides?”
A1. Two points:
1) See step 5 of the linked surgical technique (linked here), “Grasp and pull free cable tails equally taut to remove slack in the cables”.
2) See 3rd bullet point below Step 5, “the ends should be pulled taut so as to equalize their length”. If this is done correctly, the tension in each strand should be the same. Also note that the cable is actually comprised of one strand, looped around the clasp, so any difference in tension tends to even out as you tighten.
Q2. Are there any issues implanting SuperCable with typical joint prosthesis’ in terms of using two types of metal?
A2. This should not be a problem as long as the SuperCable clasp (Ti 6Al/4V) is not in direct contact with the implant. Additionally, it should be noted that the cable strand must not pass over any sharp implant edges or roughed ingrowth features on the prosthesis which may damage the polymer cable. The SuperCable clasp is made from titanium alloy (Ti 6AI/4V). The primary concern when mixing metals is galvanic corrosion. Mixing of stainless steel and titanium is generally not advisable although if there is no direct contact between the metals this may be acceptable. Mixing of CoCr and titanium is generally accepted (note that CoCr heads have been mounted on titanium alloy stems for 50+ years). [Read More on this subject]
Q3. Does the Titanium Alloy contain any nickel?
A3. No. SuperCable is a great implant choice for patients with nickel allergies. A statement regarding this is linked here.
Q4. Can the SuperCable system be used in children?
A4. “Skeletally immature patients” is a standard contraindication for cerclage systems. In fact, Dall-Miles cables have the same contraindication. In general, note that if a surgeon needs to do a hardware removal, SuperCables are much easier to remove than metal cables.
Q5. In a video presentation by Kinamed, it is mentioned that the plate is placed on the lateral greater trochanter whereas the Zimmer plate reaches over the greater trochanter. What is the design rationale for it not reaching over the GT and what would the benefits be for the Kinamed plate over the Zimmer plate?
A5. This recent Blog Post thoroughly addresses question . The results of the Berend study (linked here) validate the design concept in an extremely challenging series of cases. Page 8 of the Q1 2015 Newsletter (linked here) puts their results in context.
Q6. What is the width of the grips? Length of the cable?
A6. Grips are approximately 17.5 mm (around 11/16”) wide. The length of the double strand of cable is approximately 394 mm (or 15.5”).
Q7. The cables are a differentiated product, and it would be helpful to be able to say from a design or clinical perspective that it is important to use the cables with Kinamed plates and screws. Could you please advise if you have any clinical and/or marketing information that would help our sales team justify why a surgeon should use Kinamed plates and screws with Kinamed cable.
A7. There are a many reasons to use our Grip & Plate system over the competition’s.
- SuperCable Grips & Plates are designed to work with the ONLY non-metallic cerclage system on the market. The cable through-holes allow for a secure and low profile construct and it minimizes the potential for the cerclage cable to migrate proximally or distally.
- SuperCable trochanteric grips are anatomically friendly (see earlier question).
- As a Kinamed sales representative you earn a commission selling Kinamed Grips and Plates.
- When a surgeon “cable” customer uses Kinamed SuperCable Grips & Plates, the competitive grip/plate company has no need to see your customer for a “SuperCable surgery”. Always good to keep the competition out!
- You can point out to the hospital that it adds cost-per-case to use a system that requires eyelets or other small components to belay each cable into place on a plate.
Other features unique to the SuperCable Grip & Plate System:
- Ability to utilize locking or compression screws in any screw-hole. Either screw type can be placed in either end of oval screw-hole for more placement options.
- Ability to place a short locking screw directly into the trochanteric fragment or adjacent to implant components. This is a design feature surgeons tell us that they really like about our system.
- Contoured proximal anatomic fit.
- Sharp proximal hooks to penetrate musculature and secure trochanter.
- Small distal anti-rotation hooks.
- Curved Cable-Plate in long sizes to match femoral bow.
- Bi-directional screw holes allow dynamic compression to be applied in either direction.
- Screw-holes offset from centerline for increased flexibility in obtaining optimal bone purchase.
- Compression screws can be angled up to 57º and 16º to make best use of available bone stock.
More information can be found on our website, brochure, and surgical technique.
Q8. The brochures claim that the Kinamed cable has greater fatigue strength than wire cables. Do we have data to support this?
A8. The linked “cable strength letter” and “Cerclage Abstract” documents summarize the fatigue strength data we have. This provides direct comparison data to the metal cables, with the key point being – after one million cycles – our cable exhibits no fraying or breakage, while the metal cables have broken. This is also addressed in our brochure and website under the “Fatigue Strength Testing” section. You can view a video of the test here. It’s always a good idea to point out to surgeons that SuperCable’s clinical results are the most important factor, and we have several peer-reviewed studies by highly reputable surgeons that speak to the clinical effectiveness of SuperCable (Della Valle, Edwards, Berend, Rosenwasser).
Q9. Can the cables be loosened during surgery or only tightened?
A9. No, the cables cannot be loosened during surgery. We recommend you focus the surgeon’s attention on the ability to add tension after previously locking the cable. Once surgeons understand how easy and convenient it is to add tension to a previously locked SuperCable, the issue of not being able to “un-lock” the cable is diminished. There is a tool to unlock the demo cables, but it is not to be used in surgery. Use of this tool is described on the linked “Demo item instructions”, and in this video (linked here).