HANSSON TWIN HOOK® - Osteosyntese

on et al. Int. Orth. 2002Olsson et al. Int. Orth. 2002High resistance against displacementFull contactPoint contactFig. 5. HanssonTwin HookFig. 4.Fig. 6. CompressionHip ScrewTwo hooks are positioned anterior and posterior with a total hook span of 31 mm.The hooks will be in contact with both cancellous and subchondral bone in the femoralhead, providing a very good support against displacement.The Hansson Twin Hook will allow full bone and implant surface contact along the entireimplant for better support against varus angulation (Figs. 5 and 6).Torsional testTorque (N/m)9876543Torque deformation graph showing torsional loadingof a compression hip screw and a HanssonTwin Hook in two femoral heads with bonemineral density of 260 and 310 kg/m 3respectively, during 40° clockwiseand 40° counter-clockwise rotation.Twin HookCompression Hip Screw210Axial load (kN)Clockwise rotation 0-40° Counter clockwise rotation 0-40°The Hansson Twin Hook gives 2-3 times better rotational resistance in cadaver femoralheads than a compression hip screw. Rotational stability of the Hansson Twin Hook in the1.8plate barrel is ensured through bilateral flattening of the shaft to match the inside of the hip1.6plate barrel.1.4Note: The test was done with the first version of the Hansson Twin Hook.The frontal area of the current version of the Hansson Twin Hook is 25% larger.1.210.80.6Twin Hook

MINIMAL SURGICALTRAUMAUnlike other devices, such as the standard compression hip screw system,the Hansson Twin Hook and operative procedure are both designed tominimize surgical trauma.No rotational forces during insertionThe Swemac Hip Plate is insertedthrough a 50 mm skin incision.The plate/barrel is pushed intothe pre-drilled hole in the lateralcortex.A. B.C. D.The smooth profile of the implant allows the Hansson Twin Hook toslide into place without twisting or hammering, thus minimizing the riskof displacement and greatly improving the chance of preserved femoralhead vitality.The Hansson Twin Hook and theintroducer assembly are insertedthrough the plate/barrel and usedas a joystick. When the HanssonTwin Hook have reached its finalposition, the introducer handle isturned clockwise as far as itwill go.Minimal operative exposureThe complete procedure can be carried out through a 30-70 mmskin incision. A minimal operative exposure offers the followingpotential benefits:n Reduced bleedingn Reduced need for bloodtransfusionn Shorter operating timen Reduced risk of infectionn Less postoperative painn Early mobilisationn Early return to pre injury statusn Cosmetic, patient satisfactionAll cortical bone screws securingthe plate to the shaft can beintroduced through the same skinincision.

Minimal damage to cancellous bone62 mm 2 126.7 mm 2The damage to cancellous bone when using the Hansson Twin Hook is approximately50% less when compared to a compression hip screw.Percutaneous removal procedureThe Hansson Twin Hook can be removed through a 10 mm skin incision without theneed to remove the plate. The operation can be performed under local anaesthesia.Percutaneous removal can be advantageous in the case of a femoral head penetration,or if the patient suffers from soft tissue irritation after fracture healing, caused bythe distal end of the Hansson Twin Hook protruding into the soft tissue.Fig. 7 Fig. 8The Hansson Twin Hook has penetrated the joint (Fig. 7). It was removed through a 10 mmskin incision under local anaesthesia and a new shorter implant was inserted. The fractureis stable, due to previous impaction, and healed successfully (Fig. 8).

Swemac Orthopaedics ABIndustrigatan 11 • SE-582 77 Linköping • SwedenHansson Twin Hook • 0306Phone +46 (0) 13 37 40 30 • Fax +46 (0) 13 14 00 26E-mail info@swemac.com • www.swemac.com