Three-dimensional kinematic analysis of knee joint after anterior cruciate ligament reconstruction with personalized femoral positioner based on apex of deep cartilage / 中国修复重建外科杂志

OBJECTIVE@#To investigate the changes of knee joint kinematics after anterior cruciate ligament (ACL) reconstruction assisted by personalized femoral positioner based on the apex of deep cartilage (ADC).@*METHODS@#Between January 2021 and January 2022, a total of 40 patients with initial ACL rupture who met the selection criteria were randomly divided into the study group (using the personalized femoral positioner based on ADC design to assist ACL reconstruction) and the control group (not using the personalized femoral positioner to assist ACL reconstruction), with 20 patients in each group. Another 20 volunteers with normal knee were collected as a healthy group. There was no significant difference in gender, age, body mass index, and affected side between groups ( P>0.05). Gait analysis was performed at 3, 6, and 12 months after operation using Opti _ Knee three-dimensional knee joint motion measurement and analysis system, and the 6 degrees of freedom (flexion and extension angle, varus and valgus angle, internal and external rotation angle, anteroposterior displacement, superior and inferior displacement, internal and external displacement) and motion cycle (maximum step length, minimum step length, and step frequency) of the knee joint were recorded. The patients' data was compared to the data of healthy group.@*RESULTS@#In the healthy group, the flexion and extension angle was (57.80±3.45)°, the varus and valgus angle was (10.54±1.05)°, the internal and external rotation angle was (13.02±1.66)°, and the anteroposterior displacement was (1.44±0.39) cm, the superior and inferior displacement was (0.86±0.20) cm, and the internal and external displacement was (1.38±0.39) cm. The maximum step length was (51.24±1.29) cm, the minimum step length was (45.69±2.28) cm, and the step frequency was (12.45±0.47) step/minute. Compared with the healthy group, the flexion and extension angles and internal and external rotation angles of the patients in the study group and the control group decreased at 3 months after operation, and the flexion and extension angles of the patients in the control group decreased at 6 months after operation, and the differences were significant ( P<0.05); there was no significant difference in the other time points and other indicators when compared with healthy group ( P>0.05). In the study group, the flexion and extension angles and internal and external rotation angles at 6 and 12 months after operation were significantly greater than those at 3 months after operation ( P<0.05), while there was no significant difference in the other indicators at other time points ( P>0.05). There was a significant difference in flexion and extension angle between the study group and the control group at 6 months after operation ( P<0.05), but there was no significant difference of the indicators between the two groups at other time points ( P>0.05).@*CONCLUSION@#Compared with conventional surgery, ACL reconstruction assisted by personalized femoral positioner based on ADC design can help patients achieve more satisfactory early postoperative kinematic results, and three-dimensional kinematic analysis can more objectively and dynamically evaluate the postoperative recovery of knee joint.

Comparison of efficacy of femoral tunnel creation with figure-of-four position and traditional knee hyperflexed position for arthroscopic anterior cruciate ligament reconstruction using tendon autograft / 中华创伤杂志

Objective:To compare the efficacy of arthroscopic anterior cruciate ligament reconstruction using tendon autograft with figure-of-four position and traditional knee hyperflexed position for femoral tunnel creation.Methods:A retrospective case series study was conducted to analyze the clinical data of 46 patients with ACL injury admitted to Second Affiliated Hospital of Harbin Medical University from August 2019 to October 2019, including 26 males and 20 females; aged 24-40 years [(31.1±7.5)years]. All patients underwent arthroscopic ACL reconstruction using tendon autograft. The femoral tunnel was created with figure-of-four position in 21 patients (figure-of-four position group) and with traditional knee hyperflexed position in 25 patients (knee hyperflexed position group). The operation time was compared between the two groups. The center position, length and angle of femoral tunnel were evaluated and measured by three dimensional CT reconstruction and Bernard quadrant method at 8 weeks postoperatively. The knee function was assessed by knee Lysholm score preoperatively, at 8 weeks and at 1 year postoperatively. Complications were observed as well.Results:All patients were followed up for 2-20 months [(15.3±2.1)months]. The operation time was (28.5±2.6)minutes in figure-of-four position group, significantly less than (39.5±2.4)minutes in knee hyperflexed position group ( P<0.05). The tunnel center position was located at (27.1±1.4)% and (25.1±2.6)% within the Bernard quadrant in figure-of-four position group, similar with (28.1±2.8)% and (26.1±3.1)% in knee hyperflexed position group (all P>0.05). Total tunnel length and thick tunnel length were (42.1±2.4)mm and (34.1±2.4)mm in figure-of-four position group, significantly longer than (38.2±2.5)mm and (31.1±2.7)mm in knee hyperflexed position group (all P<0.05). The coronal plane angle of the tunnel was (41.1±2.4)° in figure-of-four position group, significantly smaller than (47.5±2.6)° in knee hyperflexed position group ( P<0.05). The sagittal plane angle of the tunnel was (42.1±1.4)° in figure-of-four position group, significantly greater than (37.1±1.8)° in knee hyperflexed position group ( P<0.05). Figure-of-four position group showed the knee Lysholm score of (53.4±5.2)points preoperatively, (97.1±1.4)points at 8 weeks postoperatively and (98.3±2.3)points at 1 year postoperatively. Knee hyperflexed position group showed the knee Lysholm score of (54.3±7.4)points preoperatively, (97.1±1.6)points at 8 weeks postoperatively and (98.1±1.3)points at 1 year postoperatively. The knee Lysholm score did not differ significantly between the two groups (all P>0.05), but the knee function was significantly improved in both groups when compared with that before the operation (all P<0.05). There were 1 patient with femoral tunnel fracture, one with injury to the medial condylar cartilage and one with injury to the posterior root of lateral meniscus in knee hyperflexed position group, while no above-mentioned complications occurred in figure-of-four position group ( P<0.05). Conclusion:Arthroscopic ACL reconstruction using tendon autograft with femoral tunnel creation through figure-of-four position and traditional knee hyperflexed position can both contribute knee functional recovery, but the figure-of-four position has the advantages of short operation time, accurate tunnel positioning, favorable length and angle of the tunnel and less complications.

Comparison of femoral tunnel and early curative effect analysis between arthroscopic three approach and traditional anteromedial portal for reconstruction of anterior cruciate ligament / 中国骨伤

OBJECTIVE@#To study the three-approach and traditional anterior medial technique to establish the femoral tunnel of position, length, and coronal angle and the early efficacy of anterior cruciate ligament reconstruction.@*METHODS@#Through retrospective research, from December 2018 to June 2019, a total of 36 patients diagnosed with simple anterior cruciate ligament tear and undergoing surgery were collected. All patients had a clear history of knee sprains and were divided into two groups. A group of 16 patients, including 11 males and 5 females, with an average age of (30.13±6.54) years and an injury time of 7 to 60 (30.19±15.78) days, three-approach technique was used to drill the femoral tunnel to reconstruct the anterior cruciate ligament. Another group of 20patients, including 15 males and 5 females, with an average age of (30.80±8.60) years, and an injury time of 7 to 60 (27.35±15.50) days, the traditional anterior medial approach was used to drill the femoral tunnel to reconstruct anterior cruciate ligament. CT 3D reconstruction technique was used to evaluate the femoral tunnel and the knee joint function was evaluated by Lysholm score of the knee joint.@*RESULTS@#All patients achieved primary healing after the surgical incision. No femoral tunnel fracture, vascular and nerve damage, difficulty in graft passage during the operation, and venous thrombosis occurred. All 36 patients were followed up on an outpatient basis, with a follow up period of 9 to 15 (12.00±2.83) months. Three-dimensional CT reconstruction was used to evaluate the femoral tunnel of the patients. The position of the femoral tunnel was described using the quartile method as the three-approach group:the lower (27.83±1.97) % of the femoral condyle and the posterior (25.57±3.20) %;the traditional approach group:the lower (28.38±3.21) % of the femoral condyle and the posterior (26.23±3.20) %. Bone tunnel length, three-approach group:(35.20±5.52) mm in total length, (23.20±2.07) mm in thick bone tunnel;traditional approach group:(34.60±4.26) mm in total length, (22.56±2.50) mm in thick bone tunnel. Coronal plane angle, three-approach group:(47.93±5.98) °;traditional approach group:(41.78±6.62) °. Knee joint Lysholm score, three-approach group:48.67±4.18 before surgery;97.00±2.48 at last follow up;traditional approach group:49.75±5.33 before surgery, 97.30±2.68 at last follow up, there were significant differences before and after surgery, no significant statistical difference between two groups.@*CONCLUSION@#The positions of the femoral tunnel drilled by the two methods were within the range of the anatomic stop of the anterior cruciate ligament, and there was no statistical difference. Compared with the traditional anterior medial approach, the coronal plane angle of the femoral tunnel drilled by the three-approach approach is relatively large, and there were no statistical differences in the length of the tunnel, the early postoperative effect of the two surgical methods, and the operation time. But the three approach has a wider and clearer vision. In addition, the knee flexion angle required for drilling the femoral tunnel during surgery is significantly smaller than that of traditional approach technology, which reduces the difficulty of surgery.

Accuracy of bone tunnel in anterior cruciate ligament reconstruction using electromagnetic navigation system / 中国组织工程研究

BACKGROUND: Accuracy and repeatability of bone tunnel in anterior cruciate ligament reconstruction has been a difficult point in surgery. As a new navigation technology, electromagnetic navigation system can realize three-dimensional positioning in application, hoping to make up for the mistakes made by surgeons. OBJECTIVE: To evaluate the feasibility and accuracy of a new electromagnetic navigation system in anterior cruciate ligament reconstruction. METHODS: Totally 30 cases of fresh frozen knee joint were treated with anterior cruciate ligament amputation to prepare knee joint specimens with anterior cruciate ligament rupture. They were randomly divided into two groups, using magnetic channel navigation combined with arthroscopy (navigation group) and traditional arthroscopy (control group). Postoperative lateral radiography of knee joint was performed to observe the exit position of bone tunnel in two groups, to measure the position of the middle of the tibial tunnel on the tibial plateau, to measure the a angle between the Blumensaat line and the axis of the tibial tunnel, and to measure the position of the femoral tunnel on the Blumensaat line. RESULTS AND CONCLUSION: (1) In the navigation group, the lateral X-ray radiographs of knee joint extension showed that the front edge of all tibial tunnels was slightly behind of Blumensaat line, avoiding intercondylar collision. In control group, two cases were located slightly ahead of Blumensaat line. (2) The distance (a) between the Blumensaat line at the level of tibial plateau and the front edge of the tibial tunnel, the ratio of a to width of tibial plateau anteroposterior diameter (c) and alpha angles of tibial tunnel were smaller in the navigation group than in the control group (P < 0.05). This increased the accuracy of tibial tunnel positioning. (3) There was no significant difference in the location of the tibial tunnel between the two groups (P=0.323). However, the range of the central position of the tunnel (38.1 %-53.8%) was slightly lower in the navigation group than that in the control group (30.4%-56.4%). The range of a distance (0.1-3.2 mm) in the navigation group was smaller than that in the control group (-2.1-5.7 mm), and the location of bone marrow tract was more stringent, which increased the repeatability of location tibial tunnel. (4) The position of femoral tunnel was in the position of the posterior upper quadrant (4/4) in all navigation groups and in 13 cases of the control group. The position of femoral tunnel in the navigation group was more backward compared with the control group (P=0.001). The femoral tunnel in the navigation group could ensure the stability of the knee. (5) In the cadaveric knee joint experiment, magnetic navigation technology can be used to assist the location of bone tunnel in anterior cruciate ligament reconstruction, increase the accuracy and repeatability of bone tunnel, but there are still artificial and magnetic channel navigation system errors, which still need to be improved in clinical application.

Short term clinical results of single bundle ACL reconstruction, with a quadruple autologous hamstring graft, modified transtibial versus anteriomedial portal approach for femoral tunnel

Anteriior cruciate ligament injuries are known to be the most common spots injuries, and ACL reconstruction is widely used because of the low success rate of convservative treatment. This study was aimed to compare the short-terma functional results of modifying transtibial and transportal technique for femoral tunnel drilling. This Retrospective comparative case control study included 76 patients with an isolated ACL tear, operated with ST tendon autograft ACL reconstruction by the same surgical tea. 36 patients operated with a modified transtibial approach and 40 patients with an antreomedial approach for femoral drilling. The results of the current study revealed that the mean age in the series was 26 years; the majority of patients were male, only 6 patient's asses again after two years of surgery, by instability tests and lysholm scores reveal no significant differences between two group regarding anterioposterior and rotatory instability, also comparable lysholm score results. The Study concluded that modified transtibial femoral drilling of the femoral tunnel in ACL reconstruction surgery is still useful and give comparable results as tranportal drilling (AU)

Ressarch of prior-localization femoral tunnel in medial patellofemoral ligament reconstruction / 中国修复重建外科杂志

Objective: To introduce the method of prior-localization femoral tunnel by using a special positioning tool under the C-arm radiographic machine before surgery, and to study the effect on the knee function recovery after medial patellofemoral ligament (MPFL) reconstruction. Methods: Between January 2014 and January 2016, 32 patients with recurrent unilateral knee patellar dislocation were treated by arthroscopic patellofemoral lateral retinaculum release and MPFL reconstruction. The femoral tunnel position during MPFL reconstruction was prior-localizated under C-arm radiographic machine before operation. There were 8 males and 24 females, aged from 15 to 37 years, with an average of 23.8 years. The time from injury to admission ranged from 1 to 24 months, with an average of 9.7 months. Isometric point distance was measured on CT three-dimensional reconstruction image after operation to evaluate whether the position of femoral tunnel was isometric, and knee joint function was evaluated by Lysholm score. Spearman correlation analysis was performed between isometric point distance and Lysholm score. Results: All the 32 patients were followed up 12-18 months (mean, 14.2 months). No symptoms of patellar subluxation or dislocation was found during follow-up. Patellar extrapolation test and patellar extrapolation fear test were negative. The isometric point distance was 1.5-5.9 mm (mean, 3.44 mm) at 3 days after operation. All femoral tunnels were located in equidistant tunnels. At last follow-up, the Lysholm score of the patients was 92.8±2.1, which was significantly improved when compared with preoperative score (54.4±2.8) ( t=61.911, P=0.000). Isometric point distance was negatively correlated with Lysholm score ( r=-0.454, P=0.009). Conclusion: C-arm radiographic machine can locate the femoral tunnel position of MPFL easily and accurately before operation. The short-term and medium-term effectiveness are satisfactory, and the ionizing radiation injury caused by multiple fluoroscopy during operation is avoided.

Clinical results of arthroscopic anterior cruciate ligament reconstruction with short femoral tunnel / 中国骨伤

OBJECTIVE@#To evaluate the clinical outcome of arthroscopic reconstruction of anterior cruciate ligament (ACL) with short femoral tunnel.@*METHODS@#From May 2013 to June 2017, 128 patients with anterior cruciate ligament reconstruction were performed with Transportal technique. Among them, 32 cases had short femoral tunnel were included, including 13 males and 19 females, aged 25.8 (17 to 43) years old, with a mean history of (4.5±1.1) months. The tibial tunnels were drilled in the middle of the footprint of the ACL, and femoral tunnels were drilled by transportal technique. Grafts were fixed with Endobutton at the femoral side and with interference screw at the tibial side. The changes of symptoms and signs were observed and the anterior tibial displacement was measured. The function of knee joint was evaluated by Lysholm score and Tegner score.@*RESULTS@#All patients were followed up for over 2 years. At the latest follow-up, 30 patients were negative and 2 patients were positive in knee shift test; 28 patients were negative in Lachman sign, 4 patients were positive in degree I; 30 patients were negative in anterior drawer test, 1 patient was positive in degree I and 1 patient was positive in degree II. The anterior displacement of the tibia increased by (2.6±1.8) mm compared with the healthy side, which was significantly different from that before operation (=19.77, <0.05). Lysholm score of 82.2±6.1 was significantly higher than that before operation (=17.33, =0.001). According to Lysholm score evaluation, 15 cases got an excellent result, 10 were good, 7 were fair, and no bad results, with a significant difference compared with that before operation (=-7.151, <0.05). Tegner motor function score of (7.4±0.6) was significantly different from that before operation (=9.11, =0.000 5). After operation, the knee joint movement ability of the patients improved significantly. Twelve patients could participate in antagonistic sports and 15 patients could participate in non-antagonistic sports. Fifteen patients were very satisfied with the curative effect, 13 patients were satisfied with the curative effect.@*CONCLUSIONS@#The incidence of short femoral tunnel in anterior cruciate ligament reconstruction with transportal technique is 25%. At present, the clinical effect of patients with short tunnel is acceptable. However, due to the lack of comparative study, the effect of short tunnel on the curative effect is still unclear.

The femoral tunnel view test during ACL reconstruction can ensure tunnel integrity / O teste de visualização artroscópica do túnel femoral durante a reconstrução do LCA garante a integridade do túnel

ABSTRACT Objective: Violation of the posterior femoral cortex commonly referred to as posterior wall blowout, can be a devastating intraoperative complication in anterior cruciate ligament reconstruction (ACLR) and can lead to loss of graft fixation or early graft failure. This study describes and analyzes whether the femoral tunnel view test can ensure the integrity of the femoral tunnel during ACLR. Methods: Intraoperative femoral tunnel integrity using the 360º arthroscopic view test was performed in 584 ACLR patients between 2014 and 2016. Posterior wall blowouts were described by their location along the femoral tunnel (i.e., near the aperture or more proximal) and by the depth of the tunnel blowout (<3 mm, 3-5 mm, >5 mm), corresponding to the length of the posterior cortical wall of the violated femoral tunnel. The time spent for the test was measured during ACLR. Complications related to the femoral tunnel view test were also evaluated. Results: The femoral tunnel view test was performed in all 584 patients. In 12 patients (1%), the femoral tunnel presented a posterior cortical blowout that did not extend beyond 3 mm. Only four patients (0.6%) presented posterior wall blowout that extended beyond 5 mm. The time for the test was 40 s (±20 s). No complications related to the test were reported. Conclusion: The femoral tunnel view test is effective for ensuring the integrity of the femoral tunnel during ACL reconstruction, without increasing the surgical time and without an increase in the complications rate. Clinical relevance: The femoral tunnel view test is a quick and straightforward test able to provide an adequate view of the patient's anatomy to ensure tunnel integrity during ACLR.

RESUMO Objetivos: A violação da cortical femoral posterior pode ser complicação intraoperatória devastadora na reconstrução do ligamento cruzado anterior (RLCA), pode levar à perda de fixação ou à falha precoce do enxerto. Este estudo descreve e analisa a capacidade do teste de visualização artroscópica do túnel femoral em evidenciar a integridade de suas paredes durante a RLCA. Métodos: Foram prospectivamente avaliados 584 pacientes elegíveis à RLCA entre 2014 e 2016 quanto à integridade do túnel femoral com o uso do teste de visualização artroscópica. A localização ao longo do túnel femoral e a profundidade da violação no túnel (< 3 mm, 3-5 mm, > 5 mm) foram avaliadas. O tempo para o teste foi medido e a ocorrência de complicações relacionadas ao mesmo também foi analisada. Resultados: Todos os 584 pacientes elegíveis foram submetidos ao teste de visualização do túnel femoral durante a cirurgia artroscópica para RLCA. Em 12 (1%) pacientes, o túnel femoral apresentou perda de integridade da cortical posterior, que não ultrapassou 3 mm. Apenas quatro (0,6%) pacientes apresentaram violação da cortical posterior, que se estendeu para além de 5 mm. O tempo médio dispendido no teste foi de 40 segundos (± 20). Nenhuma complicação realização foi relatada. Conclusão: O teste de visualização do túnel femoral é eficaz para avaliar a integridade desse túnel durante a RLCA, sem aumentar o tempo cirúrgico e sem provocar aumento na taxa de complicações relativas ao procedimento. Relevância Clínica: O teste de visualização artroscópica do túnel femoral é uma técnica simples e rápida, capaz de obter visão adequada da anatomia do paciente, garante a integridade do túnel durante a RLCA.

Ensayo pictórico: descripción del posicionamiento del túnel femoral en distintas técnicas de reconstrucción del ligamento cruzado anterior (lca) / Pictory essay: description of the positioning of the femoral tunnel in different techniques of reconstruction of the anterior cruciate ligament

En la práctica radiológica habitual el radiólogo se encuentra frecuentemente con distintas técnicas de reconstrucción del LCA que debe conocer de manera general para una adecuada descripción e interpretación de los hallazgos. En el presente ensayo pictórico exponemos diferentes tipos de técnica de reconstrucción del LCA, con énfasis en el concepto de reconstrucción anatómica, presentando distintas posiciones del túnel femoral, buscando entregar herramientas al radiólogo para reconocer la normalidad postoperatoria e interpretar posibles complicaciones.

In daily radiological practice, we frequently fid different ACL reconstruction techniques, which we must know in order to achieve adequate interpretation of the fidings. In this pictorial essay, we show different types of LCA reconstruction techniques, highlighting the anatomical reconstruction concept and presenting different positions of the femoral tunnel, seeking to deliver tools to the radiologist in order to recognize the normal postoperative fidings and possible complications.

Magnetic Resonance Imaging and Clinical Results of Outside-in Anterior Cruciate Ligament Reconstruction: A Comparison of Fixed- and Adjustable-Length Loop Cortical Fixation

BACKGROUND: Cortical suspensory femoral fixation is commonly performed for graft fixation to the femur in anterior cruciate ligament (ACL) reconstruction using hamstring tendons. The purpose of this study was to compare graft healing in the femoral tunnel, implant-related failure, and clinical results between fixed- and adjustable-length loop devices in outside-in ACL reconstruction. METHODS: A total of 109 patients who underwent ACL reconstruction using the outside-in technique from December 2010 to July 2014 were included. For femoral graft fixation, a fixed-length loop device was used in 48 patients (fixed-loop group) and an adjustable-length loop device was used in 61 patients (adjustable-loop group). For evaluation of graft healing in the femoral tunnel, magnetic resonance imaging was performed at postoperative 6 months and the signal-to-noise ratios (SNRs) of the tendon graft and tendon-bone interface in the femoral bone tunnel were evaluated. The presence of synovial fluid was evaluated to determine loop lengthening at the femoral tunnel exit. Clinical results assessed using International Knee Documentation Committee score, Tegner-Lysholm Knee Scoring scale, and knee instability tests were compared between groups. RESULTS: The SNRs of the tendon graft and tendon-bone interface were not statistically different between groups. The presence of synovial fluid at the femoral exit showed no statistical difference between groups. Clinical results were not significantly different between groups. CONCLUSIONS: The adjustable-length loop device provided comparable graft healing, implant-related failure, and clinical results with the fixed-length loop device, allowing adaptation of the graft to the different tunnel lengths. Therefore, it could be effectively used with an adjustment according to the femoral tunnel length.

Effect of Anteromedial Portal Entrance Drilling Angle during Anterior Cruciate Ligament Reconstruction: A Three-Dimensional Computer Simulation

PURPOSE: The object of this study was to evaluate entrance angle effects on femoral tunnel length and cartilage damage during anteromedial portal drilling using three-dimensional computer simulation. MATERIALS AND METHODS: Data was obtained from an anatomic study performed using 16 cadaveric knees. The anterior cruciate ligament femoral insertion was dissected and the knees were scanned by computer tomography. Tunnels with different of three-dimensional entrance angles were identified using a computer simulation. The effects of different entrance angles on the femoral tunnel length and medial femoral cartilage damage were evaluated. Specifically, tunnel length and distance from the medial femoral condyle to a virtual cylinder of the femoral tunnel were measured. RESULTS: In tunnels drilled at a coronal angle of 45degrees, an axial angle of 45degrees, and a sagittal angle of 45degrees, the mean femoral tunnel length was 39.5+/-3.7 mm and the distance between the virtual cylinder of the femoral tunnel and the medial femoral condyle was 9.4+/-2.6 mm. The tunnel length at a coronal angle of 30degrees, an axial angle of 60degrees, and a sagittal angle of 45degrees, was 34.0+/-2.9 mm and the distance between the virtual cylinder of the tunnel and the medial femoral condyle was 0.7+/-1.3 mm, which was significantly shorter than the standard angle (p<0.001). CONCLUSION: Extremely low and high entrance angles in both of axial plane and coronal plane produced inappropriate tunnel angles, lengths and higher incidence of cartilage damage. We recommend that angles in proximity to standard angles be chosen during femoral tunnel drilling through the anteromedial portal.

Correlation between Femoral Guidewire Position and Tunnel Communication in Double Bundle Anterior Cruciate Ligament Reconstruction

PURPOSE: The object of this study was to determine the shortest possible distances of antero-medial (AM) and postero-lateral (PL) guide wire tunnel positions required to prevent femoral bone tunnel communication in double-bundle anterior cruciate ligament (ACL) reconstruction using human cadaver knees. MATERIALS AND METHODS: The centers of femoral AM and PL bundles of 16 cadaveric knees were drilled with guide wires and the distances of guide wires, were measured upon entrance into the bone. Femoral tunnel drilling was performed using transportal technique. The diameters of AM and PL graft were 8 mm and 6 mm, respectively. CT scans were taken on each knee, and 3-dimensional models were constructed to identify the femoral tunnel position and to create AM and PL tunnel virtual cylinders. Thickness of the bone bridge between the two tunnels was measured. RESULTS: In four out of six specimens, in which the guide wires were placed at less than or equal to 9 mm, communication was noted. In specimens with guide wires placed at distances greater than or equal to 10 mm, communication was not noted. The two groups showed a statistically significant difference (p=0.008). In cases where the distance between the AM and PL femoral tunnel guide wires was 12 mm, the bone bridge thickness was greater than 2 mm along the tunnel. CONCLUSION: The technique for double bundle-anterior cruciate ligament (DB-ACL) reconstruction that we show here can avoid bone tunnel communication when AM and PL femoral guide wires are placed at least 10 mm apart, and 12 mm should be kept to preserve 2 mm bone bridge thickness.

Correlation between Femoral Tunnel Location in Three-Dimensional Computed Tomography and Femoral Tunnel Angle in Plain Radiographs after Single-Bundle Anterior Cruciate Reconstruction / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to determine correlation between femoral tunnel angle in the coronal plane on a simple radiograph and femoral tunnel location in the sagittal plane on three-dimensional computed tomography (3D-CT). MATERIALS AND METHODS: The subjects included 42 patients who underwent 3D-CT after the operation out of 70 cases of anterior cruciate ligament reconstruction using quadriceps tendon-patelllar bone autograft from April, 2009 to June, 2011. Measurement of the femoral tunnel angle was based on the anatomical axis of the femur in antero-posterior (AP) and Rosenberg views; femoral tunnel location was described as a proportional percentage on the medial surface of the lateral femoral condyle in the 3D-CT image; then the correlation between femoral tunnel angle and femoral tunnel location was analyzed retrospectively. RESULTS: Femoral tunnel angle was 41.5degrees+/-6.8degrees (range: 29.7degrees-53.9degrees) on AP radiographs, and 34.9degrees+/-6.9degrees (range: 23.8degrees-46.5degrees) on Rosenberg views. The femoral tunnel was located 36.9%+/-11.3% from posterior, and 38.1%+/-6.5% from proximal on the 3D-CT image. On plain AP radiographs, femoral tunnel angle and femoral tunnel location showed negative correlation (p<0.001, rho=-0.498), and, in comparison with Rosenberg view, they showed negative correlation (p=0.006, rho=-0.416). Twenty three patients (53.5%) had femoral tunnel in the anatomical location. Their femoral tunnel angle on AP radiographs was 43.3degrees+/-6.1degrees, while the femoral tunnel angle of patients who had femoral tunnel in non-anatomical locations was 38.4degrees+/-6.4degrees (p=0.004). In the Rosenberg picture, similar difference was observed between the two groups (p=0.012). CONCLUSION: On AP radiographs and Rosenberg views, femoral tunnel angle showed significant correlation with the femoral tunnel location on the 3D-CT image, and the group who had femoral tunnel location in the anatomical range showed a relatively higher femoral tunnel angle.

Evaluation of Femoral Tunnel Positioning Using 3-Dimensional Computed Tomography and Radiographs after Single Bundle Anterior Cruciate Ligament Reconstruction with Modified Transtibial Technique

BACKGROUND: The purpose of this study is to report a modified transtibial technique to approach the center of anatomical femoral footprint in anterior cruciate ligament (ACL) reconstruction and to investigate the accurate femoral tunnel position with 3-dimensional computed tomography (3D-CT) and radiography after reconstruction. METHODS: From December 2010 to October 2011, we evaluated 98 patients who underwent primary ACL reconstruction using a modified transtibial technique to approach the center of anatomical femoral footprint in single bundle ACL reconstruction with hamstring autograft. Their femoral tunnel positions were investigated with 3D-CT and radiography postoperatively. Femoral tunnel angle was measured on the postoperative anteroposterior (AP) radiograph and the center of the femoral tunnel aperture on the lateral femoral condyle was assessed with 3D-CT according to the quadrant method by two orthopedic surgeons. RESULTS: According to the quadrant method with 3D-CT, the femoral tunnel was measured at a mean of 32.94% +/- 5.16% from the proximal condylar surface (parallel to the Blumensaat line) and 41.89% +/- 5.58% from the notch roof (perpendicular to the Blumensaat line) with good interobserver (intraclass correlation coefficients [ICC], 0.766 and 0.793, respectively) and intraobserver reliability (ICC, 0.875 and 0.893, respectively). According to the radiographic measurement on the AP view, the femoral tunnel angles averaged 50.43degrees +/- 7.04degrees (ICC, 0.783 and 0.911, respectively). CONCLUSIONS: Our modified transtibial technique is anticipated to provide more anatomical placement of the femoral tunnel during ACL reconstruction than the former traditional transtibial techniques.

Effects of femoral tunnel placement on the isometry of grafts in PLC reconstruction / 医用生物力学

Objective To explore the influence of femoral tunnel placement on the isometry of grafts in the reconstruction of posterolateral corner of the knee (PLC). Method Knee specimens from 9 frozen human cadavers were used in the study. Five points of femoral attachment sites, including the central, proximal, distal, anterior and posterior points, were selected as femoral test points for both lateral collateral ligament（LCL）and popliteus tendon（PT）. The fibular/tibial attachment sites of LCL, PT and popliteofibular ligament（PFL） were connected to the corresponding 5 test points using the brass wire, respectively. Changes in distance between each pair of fibular/tibial and femoral points were measured during the passive knee flexion extension test (0°~90°). Results The maximal changes of distances between the LCL’s anterior, distal points and LCL’s fibular attachment site were not greater than 3 mm, and there was no significant difference between these two points; the maximal change of distance between the PT’s anterior point and PFL’s fibular attachment site were not greater than 3 mm. All of the maximal changes of distances between the PT’s 5 test points and tibial point of musculotendionous junction were greater than 3 mm. Conclusions Under the condition of fibular tunnels locating at center points of LCL and PFL attachment site, the femoral tunnel should be located at the anterior edge of LCL’s attachment site (anterior point) for LCL reconstruction, and at the anterior edge of PT’s attachment site (anterior point) for PFL reconstruction.

Rotary Instability after Anterior Cruciate Ligament Reconstruction with Single BTB Tendon / 대한정형외과학회잡지

PURPOSE: To analyze both the functional restoration and recovery of rotational and anterior-posterior stability after a single bundle ACL reconstruction using a BTB tendon. MATERIALS AND METHODS: A total of 52 patients were evaluated with an average follow up period of 32 months. A Lachman test, KT-2000 arthrometer, and Pivot shift test were performed to analyze the AP and rotational stability of the patients. The IKDC and Lysholm score was then used to evaluate the clinical results of the patients. The correlation between femoral tunnel angle and recovery of rotational stability was evaluated to determine the association between the two variables. This study also evaluated how the recovery of rotational stability affects the functional recovery of the patients. RESULTS: At the final follow up, the results indicated significant improvement according to the negative Lachman tests in 40 cases (76%), with an average of 2.92 mm anterior translation in the KT-2000 arthrometer and negative Pivot shift tests in 41 cases (79%)(p<0.05). The Lysholm and IKDC scores also showed significant improvement (p<0.05). Throughout the study, Group A was designated as those with <5 mm anterior translation and a negative Pivot shift test whereas Group B had positive test results. In Group A, the results showed 35 normal (85%), and 6 near normal (15%) cases in the IKDC score system, whereas Group B showed 2 normal (25%) and 5 near normal (62.5%) cases. Group A had an average of 89.3 in the Lysholm score system whereas Group B had a score of 60.5. On the knee tunnel view, Group A showed an average femoral tunnel angle of 49.2degrees, whereas Group B showed 63.5degrees. CONCLUSION: Decreasing the inclination of the BTB tendon using a transtibial femoral tunnel angle at either 10'30 or 1'30 will result in an excellent clinical outcome by achieving both anterior and rotational stability when operating a single bundle ACL reconstruction.

Influence of positioning of the femoral tunnel for MPFL reconstruction on the isometric characteristics of grafts / 医用生物力学

Objective To explore the influence of positioning of the femoral tunnel for medial patellofemoral ligamentre (MPFL)construction on the isometric characteristics of grafts.Method Knee specimens from ten fresh frozen cadavers were used. The attachment of medial patellofemoral ligament was observed. The distance between points from the adductor tubercle, the medial femoral epicondyle, and proximal, distal and central point of the MPFL’s femoral attachment site respectively to the middle point of its patellar attachment site were measured. Changes in length were recorded while the knee was measured by angles of knee flexion (0°, 30°, 60°, 90°, and 120°). Results The length changes in every point were compared. All of the maximal length changes of its adductor tubercle: proximal points were not greater than 3 mm. There was no significant difference between the length changes of adductor tubercle and proximal points（P>0.05）. Conclusions The position of the femoral turnel for MPFL reconstruction should be located as follows: MPFL should be at the middle point of upper edge of femoral attachment site (proximal point), and the point can appropriately be shifted to adductor tubercle.

Comparison of Radiographic Results In Anterior Cruciate Ligament Reconstruction Using Patella Tendon-Bone Autograft: Making Femoral Tunnel VIA Tibial Tunnel Versus Anteromedial Portal / 대한정형외과학회잡지

PURPOSE: This study was performed to compare the radiographic results of femoral tunnels made through the tibial tunnel and through the anteromedial portal. MATERIALS AND METHODS: From March 1996 to September 1997, fifty-five reconstructions of anterior cruciate ligament were performed. Group I (femoral tunnel through tibial tunnel) was composed of 30 cases and group II (femoral tunnel through anteromedial portal) was consisted 25 cases. On postoperative anteroposterior and lateral radiographs of knees, five angles were measured : APD/LD (angle between longitudinal axis of femoral bone block of patella tendon bone graft and that of interference screw in anteroposterior view/ lateral view), AFT (the angle between longitudinal axis of femoral tunnel and that of tibial tunnel in anteroposterior view), APFT/LFT (the angle between longitudinal axis of femoral tunnel and that of femoral shaft in anteroposterior view/ lateral view) and the graft tunnel mismatch was evaluated. RESULTS: Average APD was 1.30+/-3.13 degree in group I and 0.52+/-1.85 degree in group II (P>0.05), average LD was 4.97+/-7.62 degree and 1.48+/-3.30 degree (P0.05), and average LFT was 36.57+/-5.20 degree and 39.64+/-6.48 degree (P>0.05), respectively. CONCLUSIONS: We concluded that making a femoral tunnel through the anteromedial portal decreased the divergence between the femoral interference screw and femoral bone block of patella tendon-bone autograft.

Arthroscopic Posterior Cruciate Ligament Reconstruction with Two Graft Tendons by Combined Femoral Dual Tunnel and Modified Tibial Inlay Method

From July 1997, Authors have reconstructed the posterior cruciate ligament(PCL) deficient knees with two graft tendons; an autogenous bone-patellar tendon-bone (BPTB) and a semitendinosus tendon. At Femoral side, the two graft tendons were fixed through the two tunnels which were made at the site of foot print of PCL. The original site of anterolateral bundle of the PCL was reconstructe(I with the autogenous BPTB and the original site of posteromedial bundle with the semitendinosus tendon. At tibial side, the two graft tendons were fixed by modified inlay technique; the BPTB was fixed with a cancellous screw and the semitendinosus tendon with staples. Seven cases were followed up more than six months and authors evaluated the results with the KT-1000TM arthrometer and the posterior stress radiographs by Telos stress dcvice and compared the resu]t of injured knee with the uninjured side of each patient. The results of manual maximal displacement test with arthrometer were less than 4 mm in six patients and 8 rnm in one patient at last follow up. The average distance of posterior displacement on stress radiographs was 10.3 mm preoperatively and 2.7 mm at final follow up period. Six of the seven patients had a good stability on posterior stress radiographs compared with the uninjured side. One patient had posterior knee insta- bility on stress radiographs due to loosening of the grafted tendon and retightening of the grafted tendon was performed through the posterior approach to the proximal tibia. The original idea of femoral dual tunnel method in PCL reconstructiori is to reconstruct the PCL more anatomically and the modified tibial inlay technique can solve the problern of graft tendon abrasion at the posterior opening of the tibial tunnel in transtibial tunnel method and retightening of the loose grafted tendon is simple than the other methods of PCL reconstruction. Authors expect that this combined femoral dual tun- nel and modified tibial inlay method may improve the quality of the outcome of the arthroscopic PCL reconstruction.

Femoral Tunnel Enlargements Following Arthroscopic ACL Reconstruction / 대한정형외과학회잡지

Enlargement of bone tunnels has been noted on plain X-rays following arthroscopic ACL reconstruction. The cause of this widening is unclear, but it has been hypothesized that it may be due to either mechanical or biological cases. Ishibashi et al. reported anatomical proximal fixation resulted in the most stable reconstructed knee, with increasing instability as the level of fixation moved away from the tibial plateau. The purpose of this study is to determine if any difference exists in the amount of enlargement of the femoral tunnel following arhotoscopic ACL reconstruction with position of interference screw fixation and instability, and to know the factors which affected to the enlargement of the femoral tunnels. Total 39 patients were retrospectively reviewed for tunnel measurements radiologically at one year post-operation. (27 patients received bone-patellar tendon-bone autograft, 12 patients received bone-patellar tendon-bone autograft and Kennedy LAD-ligament augmentation device). The surgery was performed using an arthroscopic single and double incision technique. AP and lateral X-rays were obtained and the tunnels were measured by two independent observers using a digital caplper. The measurements were made at the widest part of the tunnel. Correction for magnification was performed by comparing the measured width of the interference screw used for fixation of the graft with its actual width. Statistical analysis was performed using a one-way analysis of variance(ANOVA) and t-test. 1. Radiographic tunnel enlargement of femoral side was average 2.42 mm (bone-patellar tendon-bone autograft : 2.36 mm, Kennedy-LAD and autograft : 2.56 mm)(p>0.05). 2. According to the position of the interference screw, the femoral tunnel enlargement were 2.25 mm in anatomical fixation, 2.40 mm in mid-tunnel fixation, 2.62 mm in mid-tunnel fixation, 2.62 mm in outer-tunnel fixation(p < 0.05). 3. The femoral enlargement according to the overall results(Clancy, 1982) were 2.39 mm in above good result group and 2.50 mm in below fair result group(p < 0.05). Tunnel enlargement group of femoral side was related to a distance between femoral articular surface and the position of interference screw. We conclude that femoral tunnel enlargement following arthoscopic bone tendon-bone ACL reconstruction is related to the mechanical effect rather than the properties of grafts and the clinical results.