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Paper #75 Arthroscopic fixation of the fractures of the intercondylar eminence via new portal
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ABSTRACTS
was fixed using the endobutton for the femoral side and spiked washer and screw for the tibial side. Postoperatively all patients had the same accelerated rehabilitation program. All patients were evaluated clinically and radiologically at 18 months postoperatively. The clinical examination includes, 1-Presence of PF pain. 2-Patellar crepitus. 3-Patellar irritability. 4-Range of motion. 5-thigh atrophy. The radiological examination was taken pre-operatively and at late follow-up, the following were recorded, 1- Patellar height (Insall/Salvatti ratio). 2- Sulcus angle. 3-Lateral PF angle. 4-Merchant congruence angle (CA). The pre-operative radiographic measurements were compared to the postoperative value and this was correlated to the clinical findings. Results: Anterior knee pain was present in 45% and 13.5% in both the BPTB group and STG group with a significant difference. Patellar irritability and patellar crepitus were higher in the BPTB group. Flexion contracture was present in 20% and 5.4% in both BPTB and STG group respectively. There was a positive correlation between the presence of PF pain as compared to patellar irritability, flexion contracture, and patellar crepitus in the BPTB group. Also there was a positive correlation between PF pain and thigh atrophy in both groups. Radiological investigation showed, a significant patellar tendon shortening (65%) in the BPTB group as compared to the preoperative values. There was a significant decrease in the Merchant congruence angle (CA) in the BPTB group as compared to the preoperative recorded value. Significant correlation was found between PF pain and patellar tendon shortening, but not to the postoperative recorded CA in the BPTB group. The STG group did not show significant changes in the PT length, or CA. The Lateral PF angle and the sulcus angle showed no significant changes postoperatively. Conclusions: In the BPTB group, there was a higher incidence of PF pain which correlated significantly with the PT shortening, patellar crepitus, patellar irritability, flexion contracture and thigh atrophy. In spite of significant changes in the Merchants congruence angle postoperatively in the BPTB group, it was not correlated to PF pain or PT shortening. In the STG group of ACL reconstruction, lower incidence of PF pain was found, with no significant changes in the PT length or Merchant angle. Paper #74 Hamstring-ACL-replacement In Children And Adolescents. Andree Ellermann, Presenter, ARCUS Sportklinik, Pforzheim, Germany, Christian Sobau, Viernheim, Germany Looking at the controversial Discussion about indica-
tion, transplant choice and fixation techniques in active ACL-injured patients with open physes we decided to operate even in childhood using a hamstring graft. 24 patients (14 female/10 male) operated at an age between 10 to 18 years (mean 14,3) were examined at mean f/u of 32 months (range 13-77) postoperatively. ACL-replacement was performed with a four strand hamstring graft using an Endobutton and a Suture Washer for fixation. The manually drilled tunnels were positioned transepiphyseal in the anatomic position. The mean diameter of the tunnels were 7,75 mm (range 6-10) on the femoral and 8,3 mm (range 6-11) on the tibial side. Measured with the IKDC-Score 79% were classified as normal or nearly normal. Mean Tegner Score was 7,1 (range 5-9). Three patients developed an instability within the first 12 months, two of them due to an adequate trauma. Clinical and radiological examinations did not show growth disturbances in any patient. The results did not correlate to gender. Presuming a bad progression in conservatively treated ACL- injured young patients and performing a careful operative treatment (small tunnel diameters, ligamentous graft, extracortical fixation, etc.) the above mentioned technique shows satisfying results and enables the young patient to return to every day activity and sports on a satisfying level. Paper #75 Arthroscopic Fixation Of The Fractures Of The Intercondylar Eminence Via New Portal. M. Nedim Doral, Presenter, Hacettepe University School of Medicine, Departmen, Ankara, Turkey, O. Ahmet Atay, Ankara, Turkey, Onur Tetik, Ankara, Turkey, Gu¨ rsel Leblebiciog˘ lu, Ankara, Turkey A new technique is described for arthroscopic reduction and internal fixation of fractures of the intercondylar eminence of the tibia. In this technique cannulated screws are placed through “Transquadricipital tendinous” portal. Avulsion fracture of the intercondylar eminence at the insertion of the anterior cruciate ligament (ACL) is the bony equivalent of a ligamentous rupture. This mode of ACL failure is mostly seen in children and adolescents. However, these fractures are also seen with increasing frequency in adults. Satisfactory reduction is essential to prevent nonunion or malunion of a fracture, which in turn can cause persistent problems such as knee pain, loss of extension and laxity of the ACL. The management of fractures is uncomplicated and straightforward when they are minimally displaced. However, the treatment of displaced and complete separation fractures has been controversial and there is no common
ABSTRACTS agreement about reduction and fixations of these fractures. Twelve patients (7 male, 5 female) who were treated with this technique for displaced Type II and Type III fractures of the intercondylar eminence of the tibia were reviewed at mean forty-nine months. At follow-up all of the patients had a high rate of excellent or good results without any case of non-union of the fracture or related complications, such as functional instability. Placement of cannulated screws through transquadricipital tendinous portal achieved fragment reduction easily and provided rigid fixation while avoiding arthrotomy. This procedure performed on a daily basis, under general anesthesia and allowed early mobilization and return to activity at sixth week. This report describes a new technique of arthroscopic reduction and antegrade cannulated screw fixation of displaced intercondylar eminence of tibia fractures through transquadricipital tendinous portal.
Paper #76 Foam-reinforced Tibia From An Elderly Human Is A Better Alternative Than Animal Tibia For Evaluating ACL Fixation Devices. Stephen M. Howell, Presenter, Dept Mechanical Engineering, Univ. California at Davis, Davis, CA, USA, Dustin Grover, Davis, CA, USA, Shana Bailey, Davis, CA, USA, Maury Hull, Davis, CA, USA Background: Cortical and cancellous soft-tissue fixation methods are tested in animal bone because knees from young humans are in short supply. Animal bone is denser than human bone, which may overestimate fixation properties, which include stiffness, rate of slippage, and yield. The purpose of our study is to describe a simple, inexpensive technique for reinforcing tibia from elderly humans with liquid polyurethane foam and then determine whether foam-reinforced tibia is a better substitute for young tibia than porcine tibia for evaluating soft-tissue fixation methods. Methods: Stiffness, rate of slippage and yield were determined for fixation of a four-strand tendon graft with a cortical device (WasherLoc) and a cancellous device (metal interference screw) in foam-reinforced tibia from elderly humans (average 83 years), porcine tibia (skeletally mature), and young human tibia (average 35 years). Statistics were performed using a MANOVA and unpaired T-test. Results: The overall fixation performance and individual fixation properties of a cortical and cancellous fixation method tested in foam-reinforced tibia from elderly humans were similar or more conservative than fixation properties in young human tibia. Porcine tibia
39
overestimated the fixation properties of young human tibia. Conclusions: Testing a cortical and cancellous softtissue fixation method in foam-reinforced tibia is a reasonable alternative when young human tibia is not available. The use of animal bone overestimates the performance of cortical and cancellous soft-tissue methods and should be avoided. Paper #77 Elevated Lateral Patellar Force Is Related To Increased Lateral Patellar Spin. David R. Wilson, Presenter, Beth Israel Deaconess Medical Center and Harvard M, Boston, MA, USA, Maria Apreleva, Boston, MA, USA, Arun Ramappa, Boston, MA, USA, Fraser Harrold, Boston, MA, USA Introduction: Patellofemoral pain accounts for 33.2% of all knee disorders in women and 18.1% of all knee disorders in men. It is widely assumed that this pain is caused by abnormally high pressures on the lateral facet of the patella. Surgical procedures and rehabilitation protocols aimed at relieving patellofemoral pain are designed to realign the patella so that a more even distribution of contact pressure is achieved in the joint. It is not clear which features of patellar tracking are linked to high forces and pressures on the lateral patellar facet, and therefore it is not clear which features of patellar tracking must be corrected to relieve these high forces and pressures. Research Question: Which features of patellar tracking are linked to elevated contact force on the lateral patellar facet? Methods: Nine unembalmed human cadaver knee joints were tested. Each specimen was flexed in a test rig (Oxford rig) designed to simulate a continuous loaded squat while allowing unconstrained movement between the tibia and the femur. Specimens were flexed continuously from full extension to 70 degrees of flexion under a vertical hip load of 120 N. A motion analysis system (Qualisys, Glastonbury, CT) measured movement of marker clusters fixed rigidly to the femur, tibia and patella. Patellar tilt, flexion, spin and medial-lateral shift were determined by representing patellofemoral movement with a sequence-independent gyroscopic coordinate system. A new technique was used to measure contact force and pressure and determine how they were distributed across the patella. Contact pressure and force distribution were measured with a sensor (Iscan, Tekscan, Boston, MA) fixed to the patella. Prior to loading the specimen, landmarks describing the proximal, distal, medial and lateral orientation of the patella as well as the patellar
ABSTRACTS
was fixed using the endobutton for the femoral side and spiked washer and screw for the tibial side. Postoperatively all patients had the same accelerated rehabilitation program. All patients were evaluated clinically and radiologically at 18 months postoperatively. The clinical examination includes, 1-Presence of PF pain. 2-Patellar crepitus. 3-Patellar irritability. 4-Range of motion. 5-thigh atrophy. The radiological examination was taken pre-operatively and at late follow-up, the following were recorded, 1- Patellar height (Insall/Salvatti ratio). 2- Sulcus angle. 3-Lateral PF angle. 4-Merchant congruence angle (CA). The pre-operative radiographic measurements were compared to the postoperative value and this was correlated to the clinical findings. Results: Anterior knee pain was present in 45% and 13.5% in both the BPTB group and STG group with a significant difference. Patellar irritability and patellar crepitus were higher in the BPTB group. Flexion contracture was present in 20% and 5.4% in both BPTB and STG group respectively. There was a positive correlation between the presence of PF pain as compared to patellar irritability, flexion contracture, and patellar crepitus in the BPTB group. Also there was a positive correlation between PF pain and thigh atrophy in both groups. Radiological investigation showed, a significant patellar tendon shortening (65%) in the BPTB group as compared to the preoperative values. There was a significant decrease in the Merchant congruence angle (CA) in the BPTB group as compared to the preoperative recorded value. Significant correlation was found between PF pain and patellar tendon shortening, but not to the postoperative recorded CA in the BPTB group. The STG group did not show significant changes in the PT length, or CA. The Lateral PF angle and the sulcus angle showed no significant changes postoperatively. Conclusions: In the BPTB group, there was a higher incidence of PF pain which correlated significantly with the PT shortening, patellar crepitus, patellar irritability, flexion contracture and thigh atrophy. In spite of significant changes in the Merchants congruence angle postoperatively in the BPTB group, it was not correlated to PF pain or PT shortening. In the STG group of ACL reconstruction, lower incidence of PF pain was found, with no significant changes in the PT length or Merchant angle. Paper #74 Hamstring-ACL-replacement In Children And Adolescents. Andree Ellermann, Presenter, ARCUS Sportklinik, Pforzheim, Germany, Christian Sobau, Viernheim, Germany Looking at the controversial Discussion about indica-
tion, transplant choice and fixation techniques in active ACL-injured patients with open physes we decided to operate even in childhood using a hamstring graft. 24 patients (14 female/10 male) operated at an age between 10 to 18 years (mean 14,3) were examined at mean f/u of 32 months (range 13-77) postoperatively. ACL-replacement was performed with a four strand hamstring graft using an Endobutton and a Suture Washer for fixation. The manually drilled tunnels were positioned transepiphyseal in the anatomic position. The mean diameter of the tunnels were 7,75 mm (range 6-10) on the femoral and 8,3 mm (range 6-11) on the tibial side. Measured with the IKDC-Score 79% were classified as normal or nearly normal. Mean Tegner Score was 7,1 (range 5-9). Three patients developed an instability within the first 12 months, two of them due to an adequate trauma. Clinical and radiological examinations did not show growth disturbances in any patient. The results did not correlate to gender. Presuming a bad progression in conservatively treated ACL- injured young patients and performing a careful operative treatment (small tunnel diameters, ligamentous graft, extracortical fixation, etc.) the above mentioned technique shows satisfying results and enables the young patient to return to every day activity and sports on a satisfying level. Paper #75 Arthroscopic Fixation Of The Fractures Of The Intercondylar Eminence Via New Portal. M. Nedim Doral, Presenter, Hacettepe University School of Medicine, Departmen, Ankara, Turkey, O. Ahmet Atay, Ankara, Turkey, Onur Tetik, Ankara, Turkey, Gu¨ rsel Leblebiciog˘ lu, Ankara, Turkey A new technique is described for arthroscopic reduction and internal fixation of fractures of the intercondylar eminence of the tibia. In this technique cannulated screws are placed through “Transquadricipital tendinous” portal. Avulsion fracture of the intercondylar eminence at the insertion of the anterior cruciate ligament (ACL) is the bony equivalent of a ligamentous rupture. This mode of ACL failure is mostly seen in children and adolescents. However, these fractures are also seen with increasing frequency in adults. Satisfactory reduction is essential to prevent nonunion or malunion of a fracture, which in turn can cause persistent problems such as knee pain, loss of extension and laxity of the ACL. The management of fractures is uncomplicated and straightforward when they are minimally displaced. However, the treatment of displaced and complete separation fractures has been controversial and there is no common
ABSTRACTS agreement about reduction and fixations of these fractures. Twelve patients (7 male, 5 female) who were treated with this technique for displaced Type II and Type III fractures of the intercondylar eminence of the tibia were reviewed at mean forty-nine months. At follow-up all of the patients had a high rate of excellent or good results without any case of non-union of the fracture or related complications, such as functional instability. Placement of cannulated screws through transquadricipital tendinous portal achieved fragment reduction easily and provided rigid fixation while avoiding arthrotomy. This procedure performed on a daily basis, under general anesthesia and allowed early mobilization and return to activity at sixth week. This report describes a new technique of arthroscopic reduction and antegrade cannulated screw fixation of displaced intercondylar eminence of tibia fractures through transquadricipital tendinous portal.
Paper #76 Foam-reinforced Tibia From An Elderly Human Is A Better Alternative Than Animal Tibia For Evaluating ACL Fixation Devices. Stephen M. Howell, Presenter, Dept Mechanical Engineering, Univ. California at Davis, Davis, CA, USA, Dustin Grover, Davis, CA, USA, Shana Bailey, Davis, CA, USA, Maury Hull, Davis, CA, USA Background: Cortical and cancellous soft-tissue fixation methods are tested in animal bone because knees from young humans are in short supply. Animal bone is denser than human bone, which may overestimate fixation properties, which include stiffness, rate of slippage, and yield. The purpose of our study is to describe a simple, inexpensive technique for reinforcing tibia from elderly humans with liquid polyurethane foam and then determine whether foam-reinforced tibia is a better substitute for young tibia than porcine tibia for evaluating soft-tissue fixation methods. Methods: Stiffness, rate of slippage and yield were determined for fixation of a four-strand tendon graft with a cortical device (WasherLoc) and a cancellous device (metal interference screw) in foam-reinforced tibia from elderly humans (average 83 years), porcine tibia (skeletally mature), and young human tibia (average 35 years). Statistics were performed using a MANOVA and unpaired T-test. Results: The overall fixation performance and individual fixation properties of a cortical and cancellous fixation method tested in foam-reinforced tibia from elderly humans were similar or more conservative than fixation properties in young human tibia. Porcine tibia
39
overestimated the fixation properties of young human tibia. Conclusions: Testing a cortical and cancellous softtissue fixation method in foam-reinforced tibia is a reasonable alternative when young human tibia is not available. The use of animal bone overestimates the performance of cortical and cancellous soft-tissue methods and should be avoided. Paper #77 Elevated Lateral Patellar Force Is Related To Increased Lateral Patellar Spin. David R. Wilson, Presenter, Beth Israel Deaconess Medical Center and Harvard M, Boston, MA, USA, Maria Apreleva, Boston, MA, USA, Arun Ramappa, Boston, MA, USA, Fraser Harrold, Boston, MA, USA Introduction: Patellofemoral pain accounts for 33.2% of all knee disorders in women and 18.1% of all knee disorders in men. It is widely assumed that this pain is caused by abnormally high pressures on the lateral facet of the patella. Surgical procedures and rehabilitation protocols aimed at relieving patellofemoral pain are designed to realign the patella so that a more even distribution of contact pressure is achieved in the joint. It is not clear which features of patellar tracking are linked to high forces and pressures on the lateral patellar facet, and therefore it is not clear which features of patellar tracking must be corrected to relieve these high forces and pressures. Research Question: Which features of patellar tracking are linked to elevated contact force on the lateral patellar facet? Methods: Nine unembalmed human cadaver knee joints were tested. Each specimen was flexed in a test rig (Oxford rig) designed to simulate a continuous loaded squat while allowing unconstrained movement between the tibia and the femur. Specimens were flexed continuously from full extension to 70 degrees of flexion under a vertical hip load of 120 N. A motion analysis system (Qualisys, Glastonbury, CT) measured movement of marker clusters fixed rigidly to the femur, tibia and patella. Patellar tilt, flexion, spin and medial-lateral shift were determined by representing patellofemoral movement with a sequence-independent gyroscopic coordinate system. A new technique was used to measure contact force and pressure and determine how they were distributed across the patella. Contact pressure and force distribution were measured with a sensor (Iscan, Tekscan, Boston, MA) fixed to the patella. Prior to loading the specimen, landmarks describing the proximal, distal, medial and lateral orientation of the patella as well as the patellar