Ex vivo biomechanical evaluation of extracapsular stabilization with quasi-isometric points in canine cranial cruciate ligament-deficient stifles.

BACKGROUND: Cranial cruciate ligament (CCL) disease is one of the most common causes of lameness in dogs. The extracapsular stabilization (ECS) utilizing bone anchors and monofilament nylon leader was an alternative treatment for CCL-deficient (CCLD) dogs. However, the biomechanical response of the canine stifle to such a surgical repair strategy in conjunction with the use of recently reported quasi-isometric anchoring points remains unclear. The objectives of the study were to evaluate the mobility and stability of CCL-intact, CCLD, and CCLD stifles repaired with ECS at two different pairs of quasi-isometric points (quasi-IPs). METHODS: Twelve stifle specimens from 7 dogs underwent mobility and stability tests under 4 different conditions, namely, CCL-intact, CCLD, and ECS-repaired at 2 different pairs of quasi-IPs (referred to as ECS-IP1 and ECS-IP2). The mobility tests evaluated 6 degrees-of-freedom stifle kinematics during flexion and extension. The stability tests involved cranial drawer and tibial internal rotation (IR) tests at various stifle opening angles and quantifying the cranial tibial translation (CTT) and tibial IR angles under constantly applied loadings. RESULTS: The ECS repaired at quasi-IPs was shown to restore cranial instability of the stifles with averaged CTT magnitudes < 1.4 mm. During the tibial IR test, the ECS treatments resulted in significantly less tibial IR compared to those in intact CCL stifles. The mobility tests showed similar results. CONCLUSION: The 2 chosen pairs of quasi-IPs were shown to effectively correct the excessive CTT caused by CCLD stifles, whereas the excessive tibial external rotation in comparison to those of intact stifles should be considered for its subsequent influence on joint alignment and the contact pressure applied to the stifle joint.

[Ressarch of prior-localization femoral tunnel in medial patellofemoral ligament reconstruction].

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.

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.

Treatment of recurrent patellar dislocation via knee arthroscopy combined with C-arm fluoroscopy and reconstruction of the medial patellofemoral ligament.

Recurrent patellar dislocations were treated via knee arthroscopy combined with C-arm fluoroscopy, and reconstruction of the medial patellofemoral ligaments. Between October 2013 and March 2017, 52 cases of recurrent patellar dislocation [27 males and 25 females; age, 16-47 years (mean, 21.90 years)] were treated. Arthroscopic exploration was performed and patellofemoral joint cartilage injuries were repaired. It was subsequently determined whether it was necessary to release the lateral patellofemoral support belt. Pre-operative measurements were used to decide whether tibial tubercle osteotomy was required. Medial patellofemoral ligaments were reconstructed using autologous semitendinosus tendons. Smith and Nephew model 3.5 line anchors were used to double-anchor the medial patellofemoral margin. On the femoral side, the medial patellofemoral ligament was fixed using 7-cm, absorbable, interfacial compression screws. All cases were followed for 1-40 months (average, 21 months). The Q angle, tibial tuberosity trochlear groove distance, Insall-Salvati index, patellofemoral angle, lateral patellofemoral angle and lateral shift were evaluated on X-Ray images using the picture archiving and communication system. Subjective International Knee Documentation Committee (IKDC) knee joint functional scores and Lysholm scores were recorded. Post-operative fear was absent, and no patellar re-dislocation or re-fracture was noted during follow-up. At the end of follow-up, the patellofemoral angle (0.22±4.23°), lateral patellofemoral angle (3.44±1.30°), and lateral shift (0.36+0.14°) differed significantly from the pre-operative values (all, P<0.05). Furthermore, IKDC and Lysholm scores (87.84+3.74 and 87.48+3.35, respectively) differed significantly from the pre-operative values (both, P<0.05). These findings suggest that, in the short term, recurrent patellar dislocation treatment via knee arthroscopy combined with C-arm fluoroscopy and reconstruction of the medial patellofemoral ligament was effective.

Movimento de gaveta em joelhos de cães submetidos à estabilização extracapsular após secção do ligamento cruzado cranial in vitro / Drawer movement in canine knees undergoing extracapsular stabilization after cranial cruciate ligament rupture in vitro

A técnica TightRope, que procura aperfeiçoar a estabilização extra-capsular com sutura lateral, por meio da realização de mínimas incisões e criação de túneis ósseos em pontos isométricos, que permitem a inserção de mecanismo que anula o movimento de gaveta, além de reduzir a ocorrência de complicações graves. Dessa forma, objetivou-se avaliar a modificação da técnica TightRope em joelhos de cadáveres caninos com a finalidade de disponibilizar um procedimento simples e de custo reduzido para tratamento da Ruptura do ligamento cruzado cranial (RLCCr). Experimentalmente, foram utilizados 20 membros pélvicos de dez cadáveres caninos, provenientes do setor de patologia da Universidade Norte do Paraná, os quais pesavam entre 6,3 e 24kg. Para estabilização do LCCr, rompido intencionalmente, foi adotada a técnica de TightRope modificada utilizando fio de poliamida, cavilha e emprego de um parafuso ortopédico para proporcionar a fixação óssea. Comparando os valores de deslocamento obtidos durante a realização do movimento de gaveta previamente à ruptura do LCCr e após a realização do procedimento cirúrgico, observou-se que a modificação da técnica TightRope promoveu estabilidade significativa para a maioria (12 de 20) dos joelhos testados (P=0,0033). Contudo, essa estabilidade foi inferior, quando comparada à estabilidade do ligamento intacto.

The TightRope technique, that has been developed, aims to improve the extra-capsular stabilization with lateral suture through smaller incisions and creating isometric bone tunnels at points that allow the inclusion of a mechanism that overrides the movement of drawer and reduce the occurrence of serious complications. Therefore, the objective was to evaluate the TightRope modified technique in canine cadaver knees in order to provide a simple and cost effective treatment for cranial cruciate ligament rupture (CCrLR). Experimentally; we used 20 pelvic limbs of ten canine corpses from the pathology service at the University of Northern Parana, which weighed between 6.3 and 24kg. To stabilize the cranial cruciate ligament (CCrL), which has been broken intentionally, the TightRope modified technique was adopted by using modified polyamide yarn, pin and a grub screw to provide orthopedic bone fixation. Comparing the displacement values obtained during the movement of the drawer before the break of CCrL and after the surgical procedure was observed that the TightRope modified technique provided significant stability for the majority (12 of 20) of the knees tested (P=0.0033). However, the stability of the technique was lower than the stability of the intact ligament.

Estudo comparativo in vitro do movimento de gaveta em joelhos de caninos submetidos a duas técnicas extracapsulares de correção da instabilidade após ruptura do ligamento cruzado cranial / In vitro comparative study of canine knees drawer movement submitted to two extra-capsular techniques to fix the instability after abruption of the cranial cruciate ligament

A ruptura do ligamento cruzado cranial (RLCCr) é uma desordem ortopédica comum em cães que promove a instabilidade da articulação do joelho, resultando em claudicação e alterações degenerativas progressivas desta. A melhor técnica para reparação da RLCCr ainda não está bem elucidada. A maioria das técnicas alcança uma taxa de sucesso entre 80 a 90 por cento e todas apresentam vantagens e desvantagens. O objetivo deste trabalho foi avaliar os resultados da estabilização extracapsular utilizando dois pontos distintos de ancoragem na articulação femoro-tibio-patelar como forma de tratamento da RLCCr em cães. Para tanto, foram utilizados 20 membros pélvicos de caninos. Após a RLCCr, todos os membros receberam avaliação da eficiência da técnica por meio do estudo da estabilidade crânio-caudal do joelho em flexão de 90° e extensão de 135°. As estabilizações extracapsulares realizadas nos cadáveres conferiram estabilidade crânio-caudal sem demonstrar superioridade de uma ou outra técnica, e nenhuma delas pode atribuir estabilidade isométrica quando testadas com os membros em 90° e 130°.

The rupture of the cranial cruciate ligament (RLCCr) is a common orthopedic disorder in dogs resulting in instability of the knee that promotes: lameness and progressive degenerative changes. The best technique to repair RLCCr, is not well elucidated. Most techniques achieve a success rate between 80 to 90 percent and all have advantages and disadvantages. The objective of this study was to evaluate the results of extra-capsular stabilization using two different points of anchorage in the femora tibio-patellar joint, as a way of repairing of RCCrL in dogs, which were used for 20 members of pelvic canines. After RCCrL all members were assessed to verify the efficiency of the technique through the study of cranial caudal stability of the knee in 90° of flexion and extension of 130°. The extra-capsular stabilization performed in cadavers brought stability without demonstrating superiority of either technique, and both could not give isometric stability when tested with the members positioning in the angle of 90° and 130°.

A radiological survey of femoral isometric point of anterior cruciate ligament / 中华创伤骨科杂志

Objective To investigate individual variations of the femoral isometric poiIit of anterrior cruciate ligament(ACL). Methods The femoral isometric points(i)were determined by measuring the knee joint lateral projections in 100 adults.The distances from the femoral isometric point i to the posterior border of intercondylar notch were measured and compared among 4 age groups(20 to 30 y,30 to 40 y,40 to 50 y and>50 y)by 2 × 2 factor analysis and Student-Newman-Keuls (SNK-q)Analysis to determine the effects of age and gender on the measurements. Results The average distance was(10.6±1.55)mm,ranging from 15.05 am to 7.50 mm.The 2×2 factor analysis showed the differences were signifcant between age groups(F=2.843,P=0.042)and between sexes(F=4.245,P=0.042).but the age and sex factors were not interacted (F=0.456,P=0.7 14). The SNK-q Analysis revealed the differences were significant between the 20 to 30 y group and the 40 to 50 y group as well as the>50 y group(P<0.05),but not significant between the 30 to 40 y group and the 20 to 30 y group(P>0.05).No signifieant difference was observed between any two of the 30 to 40 y group,40 to 50 y group and>50 y group(P>0.05). Conclusion Since the ACL femoral isometric points vary from person to person,it is valuable to check them twice radiologically before and during the operation.

Isometry of grafts in PCL reconstruction under femoral tunnel shifting condition / 医用生物力学

Objective To explore the isometry of grafts in PCL(posterior cruciate ligament)double-bundle re-construction under femoral tunnel shifting condition.Method Knee specimens from ten fresh frozen cadavers were used.PCL were divided into anterolateral bundles(ALB)and posteromedial bundles(PMB)to the inser-tion footorint.The anterior,postedor,proximal,distal and central points of the two bundles'femoral attachment site were respectivelyanchored to the middle of the PCL's tibial attachment site by the trial wires.Changes in length of the intra-articular part of the wires were recorded while the knee was flexed from 0°to 120°.Result The length changes in every point were compared.All of the maximal length changes of ALB's proximal,pos-todor points and PMB's proximal points were not greater than 2mm.No significant difference between the length changes of ALB's proximal point and posterior(P=0.864>0.05)was found.Conclusions The femo-ral tunnel for the PCL double-bundle reconstruction should be located as follows:ALB should be at the middle point of upper edge of femoral attachment site(proximal point),while PIVIB at the middle point of femoral attachment site(proximal point).

Isometry of grafts in PCL reconstruction under femoral tunnel shifting condition / 医用生物力学

Objective To explore the isometry of grafts in PCL(posterior cruciate ligament)double-bundle re-construction under femoral tunnel shifting condition.Method Knee specimens from ten fresh frozen cadavers were used.PCL were divided into anterolateral bundles(ALB)and posteromedial bundles(PMB)to the inser-tion footorint.The anterior,postedor,proximal,distal and central points of the two bundles'femoral attachment site were respectivelyanchored to the middle of the PCL's tibial attachment site by the trial wires.Changes in length of the intra-articular part of the wires were recorded while the knee was flexed from 0°to 120°.Result The length changes in every point were compared.All of the maximal length changes of ALB's proximal,pos-todor points and PMB's proximal points were not greater than 2mm.No significant difference between the length changes of ALB's proximal point and posterior(P=0.864>0.05)was found.Conclusions The femo-ral tunnel for the PCL double-bundle reconstruction should be located as follows:ALB should be at the middle point of upper edge of femoral attachment site(proximal point),while PIVIB at the middle point of femoral attachment site(proximal point).

Isometry of grafts in PCL reconstruction under femoral tunnel shifting condition / 医用生物力学

Objective To explore the isometry of grafts in PCL(posterior cruciate ligament)double-bundle re-construction under femoral tunnel shifting condition.Method Knee specimens from ten fresh frozen cadavers were used.PCL were divided into anterolateral bundles(ALB)and posteromedial bundles(PMB)to the inser-tion footorint.The anterior,postedor,proximal,distal and central points of the two bundles'femoral attachment site were respectivelyanchored to the middle of the PCL's tibial attachment site by the trial wires.Changes in length of the intra-articular part of the wires were recorded while the knee was flexed from 0°to 120°.Result The length changes in every point were compared.All of the maximal length changes of ALB's proximal,pos-todor points and PMB's proximal points were not greater than 2mm.No significant difference between the length changes of ALB's proximal point and posterior(P=0.864>0.05)was found.Conclusions The femo-ral tunnel for the PCL double-bundle reconstruction should be located as follows:ALB should be at the middle point of upper edge of femoral attachment site(proximal point),while PIVIB at the middle point of femoral attachment site(proximal point).

Application of anatomical isometric technique in arthroscopic reconstruction of anterior cruciate ligament and quadruple hamstring tendon autograft / 中国矫形外科杂志

[Objective]To study the feasibility and short-term effects of the arthroscopic reconstruction of ACL with LARS artificial ligaments and quadruple hamstring tendon autograft usirg anatomical isometric technique.[Method]Arthroscopic ACL reconstruction was carried out in 20 patients with ACL injuries by using the LARS artificial ligaments and quadruple hamstring tendon autograft.Bone tunnels of the femur and the tibia were prepared with ACL anatomical isometric technique.20 patients were divided into LARS artificial ligaments group(11 patients) and quadruple hamstring tendon group(9 patients).The artificial tendon group was inserted into the tunnels and fixed with two interface screws after being tightened.Quadruple hamstring tendon group was fixed with endobutton plate.[Result]The operation time were 30～80 min(mean,56 min) in LARS artificial ligaments group and 80~120 min(mean,100 min) in quadruple hamstring tendon group.No postoperative complications such as synovitis and ligament rupture and movement restriction occurred iF two groups.A follow-up check up was made in the 20 patients for 6～12 months(mean,9 months).The Lysholm scores improved from a preoperative score of 22～65(36.72～15.54) to 80～98(90.45～4.68) at follow-up(t=10.535,P

Surgical Simulation for Placement of Isometric Point of Anterior Cruciate Ligament: A System using Three-dimensional Computer Models and Rapid Prototyping Models / 대한정형외과학회잡지

PURPOSE: This research aims at developing a simulation system for training of the correct placement of isometric points in arthroscopic reconstruction of anterior cruciate ligaments, using personal computer-based software and rapid prototyping knee models. MATERIALS AND METHODS: CT scan images of the knee joints of thirteen patients were used. Simulation software was developed on V-works(Clinic3D Inc.), a three-dimensional medical imaging system. Rapid prototyping models were made of hardened starch with a 0.178 mm slice thickness. RESULTS: In the first phase, trainee surgeons can study the positions of the bony attachments of healthy anterior cruciate ligaments, and compare their multiplanar reformatting images and a three-dimensional computer model of the bones. In the second phase, trainee sur-geons can place isometric points on the three-dimensional computer models and compare the results with the points set by a supervis-ing surgeon. Finally, rapid prototyping models, which are almost identical to the actual bones, are produced to allow the trainees to observe the isometric points marked on the models. CONCLUSION: Our system can provide a patient-specific simulation environment for beginners at arthroscopic anterior cruciate ligament reconstruction. It can be used as an educational and training tool for locating the isometric point of the anterior cruciate ligament during an operation.