ART 57 1.0 04/2015-E Oval Blade Dilators Anatomical tunnel dilation in cruciate ligament surgery
One of the primary objectives in cruciate ligament surgery regardless of the employed fixation technique is the accurate anatomic placement and shape of the bone tunnels. Standard bone drills create a bone tunnel with a round cross-section. However, the original insertion zone of the anterior cruciate ligament is oval. Oval blade dilators were developed to more closely match the cross-section of the generated bone tunnel with that of the original insertion zone. These instruments are complemented by a corresponding oval tendon thickness tester. The oval blade dilators are available in various diameters (7-10 mm). The dilators are inserted in a T-shaped handle which features a special coupling mechanism. Available sizes (h x w) 5 x 7 mm 5 x 8 mm 6 x 8 mm 6 x 9 mm 7 x 9 mm 7 x 10 mm 2
Oval Tunnel Technique This technical modification was based on the consideration that an oval tunnel more closely resembles the oval femoral ACL original zone than a round tunnel. For sizes 5 x 7 mm and 5 x 8 mm, the 4.5 mm drill hole is expanded using the dilator. In the case of larger tendon diameters (6 x 8 mm, 6 x 9 mm, 7 x 9 mm, 7 x 10 mm), predrilling via the medial port is performed with a 6 mm drill. Dilation of the drill channels offers numerous advantages over drilling: More accurate restoration of anatomy The oval blade dilators were developed to comply with the individual anatomy of femoral ACL insertion. Fig. 1: Native ACL insertion 1 intercondylar line cartilage to bone transition oval tunnel insertion zone Fig. 2: Inserting the oval blade dilator in the femoral drill tunnel 1 Fig. 3: Oval tunnel 1 Less risk of iatrogenic cartilage damage at the medial femoral condyle during portal preparation The use of sharp drills may cause iatrogenic cartilage damage at the medial femoral condyle. Gentle and precise tunnel preparation The use of dilators avoids thermal damage to the bone area of the tunnel wall. 1 Photographs courtesy of Prof. Dr. med. Wolf Petersen, Martin-Luther-Krankenhaus, Berlin, Germany 3
Possibility to make fine adjustments to tunnel position If the tunnel position has to be adjusted by a few millimeters, the tunnel portal can be carefully expanded in the direction of correction (burr, curette or small chisel). The dilator follows the path of least resistance in the direction of correction. Compression of the cancellous bone Dilation achieves greater cancellous bone stability; furthermore, studies show that this leads to more stable anchoring. Quick exchange of dilators A special coupling mechanism ensures fast and easy dilator exchange. This coupling is integrated in the handle so that stable and secure handling of the dilator is always ensured. Sideward dilation of implants Metal implants (e.g., interference screws), which are either located in the drill tunnel or can only be removed with considerable difficulty, can be dilated to the side. This avoids a timeconsuming and possibly traumatic removal of implants. Evaluation of bone quality While dilators are being advanced, the operating surgeon receives tactile feedback on the condition of the bone. Soft cancellous bone is particularly easy to detect. 4
Scaling enables a contolled insertion in the drill tunnel This prevents inadvertent penetration of the second (lateral) cortex. An intact lateral cortex is necessary for many fixation techniques. A drilling system may lead to penetration of the lateral cortex. Laser markings facilitate dilation in increments Laser markings on the dilators help denote size. The smallest dilator (5 x 7 mm) has one marking whereas the next size dilator (5 x 8 mm) features two markings. The largest dilator (7 x 10 mm) has 6 markings. The markings allow the surgeon to identify the next size dilator at a glance and therefore makes gradual dilation easier. 28970 AC Blade Dilator, oval, cannulated, 5 x 7 mm 28970 AD Blade Dilator, oval, cannulated, 5 x 8 mm 28970 CF Blade Dilator, oval, cannulated, 7 x 10 mm Specially designed oval tendon thickness tester available The dimensions of the oval bone tunnel are defined during tendon thickness measurement using an oval tendon thickness tester. The height/width of the graft is displayed on the tendon thickness tester. This surgical technique was developed by PD Thore Zantop and Prof. Wolf Petersen. Scientific studies supporting this concept: Petersen W, Forkel P, Achtnich A, Metzlaff S, Zantop T. Technique of anatomical footprint reconstruction of the ACL with oval tunnels and medial portal aimers. Arch Orthop Trauma Surg. 2013 Jun;133(6):827-33 Herbort M, Tecklenburg K, Zantop T, Raschke MJ, Hoser C, Schulze M, Petersen W, Fink C. Single-bundle anterior cruciate ligament reconstruction: a biomechanical cadaveric study of a rectangular quadriceps and bone patellar tendon bone graft configuration versus a round hamstring graft. Arthroscopy. 2013 Dec;29(12):1981-90. 5
Oval Blade Dilators The following oval blade dilators are available: 28970 AC Blade Dilator, oval, for compression of the cancellous bone, cannulated, 5 x 7 mm, scaled to 70 mm, 28970 AD Blade Dilator, oval, for compression of the cancellous bone, cannulated, 5 x 8 mm, scaled to 70 mm, 28970 BD Blade Dilator, oval, for compression of the cancellous bone, cannulated, 6 x 8 mm, scaled to 70 mm, 28970 BE Blade Dilator, oval, for compression of the cancellous bone, cannulated, 6 x 9 mm, scaled to 70 mm, 28970 CE Blade Dilator, oval, for compression of the cancellous bone, cannulated, 7 x 9 mm, scaled to 70 mm, 28970 CF Blade Dilator, oval, for compression of the cancellous bone, cannulated, 7 x 10 mm, scaled to 70 mm, 6
Accessories 28900 H Handle, T-shaped, with quick coupling system, for use with Blade Dilators 28970 AC/AD/BD/BE/CE/CF 28729 SO Tendon Thickness Tester, for determining an oval tendon cross-section, for use with Blade Dilators 28970 AC/AD/BD/BE/CE/CF It is recommended to check the suitability of the product for the intended procedure prior to use. Consent to receive electronic information q Yes, I agree to receive future information by email at the following address: Email Department / Practice ZIP, Town Name Street address Signature I agree to my data being stored at KARL STORZ for this purpose. I can withdraw my consent at any time and without giving reasons by emailing KARL STORZ at info@karlstorz.com. KARL STORZ will not make these data available to third parties. 7
KARL STORZ Endoscopy-America, Inc. 2151 East Grand Avenue El Segundo, CA 90245-5017, USA Phone: +1 424 218-8100 Phone toll free: 800 421-0837 (US only) Fax: +1 424 218-8525 Fax toll free: 800 321-1304 (US only) E-Mail: info@ksea.com KARL STORZ GmbH & Co. KG Mittelstraße 8, 78532 Tuttlingen, Germany Postbox 230, 78503 Tuttlingen, Germany Phone: +49 (0)7461 708-0 Fax: +49 (0)7461 708-105 E-Mail: info@karlstorz.com www.karlstorz.com 96152055 ART 57 1.0 04/2015/EW-E