scholarly journals An Anatomically Placed Tibial Tunnel does not Completely Surround a Simulated PCL Reconstruction Graft in the Proximal Tibia

2022 ◽  
Author(s):  
Christopher Kim ◽  
Dustin Baker ◽  
Brian Albers ◽  
Scott G. Kaar
Keyword(s):  
Surface Area ◽  
Cruciate Ligament ◽  
Tibial Tunnel ◽  
Three Dimensional ◽  
Pcl Reconstruction ◽  
Posterior Cortex ◽  
Modeling Software ◽  
The Mean ◽  
Tibial Cortex ◽  
Area And Volume

Abstract Introduction It is hypothesized that anatomic tunnel placement will create tunnels with violation of the posterior cortex and subsequently an oblique aperture that is not circumferentially surrounded by bone. In this article, we aimed to characterize posterior cruciate ligament (PCL) tibial tunnel using a three-dimensional (3D) computed tomography (CT) model. Methods Ten normal knee CTs with the patella, femur, and fibula removed were used. Simulated 11 mm PCL tibial tunnels were created at 55, 50, 45, and 40 degrees. The morphology of the posterior proximal tibial exit was examined with 3D modeling software. The length of tunnel not circumferentially covered (cortex violation) was measured to where the tibial tunnel became circumferential. The surface area and volume of the cylinder both in contact with the tibial bone and that not in contact with the tibia were determined. The percentages of the stick-out length surface area and volume not in contact with bone were calculated. Results The mean stick-out length of uncovered graft at 55, 50, 45, and 40 degrees were 26.3, 20.5, 17.3, and 12.7 mm, respectively. The mean volume of exposed graft at 55, 50, 45, and 40 degrees were 840.8, 596.2, 425.6, and 302.9 mm3, respectively. The mean percent of volume of exposed graft at 55, 50, 45, and 40 degrees were 32, 29, 25, and 24%, respectively. The mean surface of exposed graft at 55, 50, 45, and 40 degrees were 372.2, 280.4, 208.8, and 153.3 mm2, respectively. The mean percent of surface area of exposed graft at 55, 50, 45, and 40 degrees were 40, 39, 34, and 34%, respectively. Conclusion Anatomic tibial tunnel creation using standard transtibial PCL reconstruction techniques consistently risks posterior tibial cortex violation and creation of an oblique aperture posteriorly. This risk is decreased with decreasing the angle of the tibial tunnel, though the posterior cortex is still compromised with angles as low as 40 degrees. With posterior cortex violation, a surgeon should be aware that a graft within the tunnel or socket posteriorly may not be fully in contact with bone. This is especially relevant with inlay and socket techniques.

3D reconstruction and calculation of surface area and volume of bell pepper

2007 ◽  
Vol 3 (1) ◽  
pp. 89-113
Author(s):  
Zoltán Gillay ◽  
László Fenyvesi
Keyword(s):  
3D Reconstruction ◽  
Surface Area ◽  
Three Dimensional ◽  
Reference Method ◽  
Bell Pepper ◽  
Three Dimensional Model ◽  
Acceptable Error ◽  
Volume Calculation ◽  
Bell Peppers ◽  
Area And Volume

There was a method developed that generates the three-dimensional model of not axisymmetric produce, based on an arbitrary number of photos. The model can serve as a basis for calculating the surface area and the volume of produce. The efficiency of the reconstruction was tested on bell peppers and artificial shapes. In case of bell peppers 3-dimensional reconstruction was created from 4 images rotated in 45° angle intervals. The surface area and the volume were estimated on the basis of the reconstructed area. Furthermore, a new and simple reference method was devised to give precise results for the surface area of bell pepper. The results show that this 3D reconstruction-based surface area and volume calculation method is suitable to determine the surface area and volume of definite bell peppers with an acceptable error.

Avoiding tibia physeal injury during double-bundle posterior cruciate ligament reconstruction

2018 ◽  
Vol 3 (1) ◽  
pp. 21-25
Author(s):  
Stockton Troyer ◽  
Nicolas G Anchustegui ◽  
Connor G Richmond ◽  
Peter C Cannamela ◽  
Aleksei Dingel ◽  
...  
Keyword(s):  
Posterior Cruciate Ligament ◽  
Cruciate Ligament ◽  
Tibial Tunnel ◽  
Double Bundle ◽  
Reconstruction Technique ◽  
Pcl Reconstruction ◽  
Turn Angle ◽  
Physeal Injury ◽  
The Impact ◽  
Killer Turn

BackgroundAnatomic studies of the paediatric posterior cruciate ligament (PCL) demonstrate that the tibial attachment spans the epiphysis, physis and metaphysis. To better reproduce the anatomy of the PCL and avoid direct physeal injury, a double-bundle PCL reconstruction technique that includes both an all-epiphysial and an all-metaphyseal tibial tunnel has been proposed. The purpose of this study was to evaluate tibial tunnel placement in a paediatric double-bundle PCL reconstruction technique that avoids direct physeal injury using a 3-D computer model.MethodsTen skeletally immature cadaveric knee specimens (ages 5–11) were used to create 3-D model reconstructions from CT scans. All-metaphyseal and all-epiphysial tibial tunnels were simulated with the goal of maintaining adequate spacing (≥2 mm) between the tibial physis and tunnels to avoid injury. The all-metaphyseal tunnel, simulated at sizes of 5, 6 and 7 mm, entered anteriorly, below the tibial tubercle (apophysis) and exited posteriorly in the metaphyseal PCL footprint, distal to the proximal tibial physis. Four-millimetre all-epiphysial proximal tibial tunnels were simulated to enter the epiphysis anteromedially and exit posteriorly at the central epiphysial region of the PCL footprint, proximal to the physis. The distance was measured from the all-metaphyseal tunnels to the physis posteriorly and from the all-epiphysial tunnels to the physis, both anteriorly and posteriorly.ResultsIn all specimens, the 4 mm all-epiphysial tunnel and the 5, 6 and 7 mm all-metaphyseal tunnels maintained adequate spacing, ≥2 mm from the physis. In the specimens aged 5–7 years, the 5, 6 and 7 mm all-metaphyseal tunnels measured a mean distance of 3.5, 2.8 and 2.5 mm from the physis, respectively. In the specimens aged 8–11 years, the 5, 6 and 7 mm all-metaphyseal tunnels measured a mean distance of 3.4, 2.9 and 2.6 mm from the physis. In the specimens aged 5–7 years, the all-epiphysial tunnel measured a mean of 2.1 mm to the physis anteriorly and a mean of 2.8 mm posteriorly. In the specimens aged 8–11 years, the all-epiphysial tunnel measured a mean of 2.2 mm to the physis anteriorly and 2.4 mm posteriorly.ConclusionThese computer-aided 3-D models of paediatric knees illustrate that 5, 6 and 7 mm all-metaphyseal tunnels as well as 4 mm all-epiphysial tunnels can be placed without direct injury to the proximal tibial physis. The margin of error for direct physeal injury is small, especially for the all-epiphysial tunnel. Further, the all-epiphysial tunnel, while reproducing the anatomy of the PCL epiphysial attachment, may also produce a more extreme ‘killer turn’ of the graft. Modifications to the all-epiphysial tunnel may be considered to reduce the impact of the high ‘killer turn’ angle on the tibia.Level of evidenceIV.

scholarly journals PCL Reconstruction Using Adjustable Buttons with Outside-In Tunnel for Tibial Fixation: A case report

2019 ◽  
Vol 7 (11_suppl6) ◽  
pp. 2325967119S0048
Author(s):  
Prettysia Suvarly ◽  
Nyoman Aditya Sindunata ◽  
Lasa Dhakka Siahaan ◽  
Tommy Mandagi ◽  
John Butarbutar
Keyword(s):  
Case Report ◽  
Cruciate Ligament ◽  
Tibial Tunnel ◽  
Pcl Reconstruction ◽  
Case Presentation ◽  
Tibial Fixation ◽  
Knee Effusion ◽  
Tunneling Method ◽  
Adjustable Button ◽  
Inside Out

Introduction: Posterior cruciate ligament (PCL) reconstruction needs a large and long graft. An allograft is a preferable option for thicker graft but its availability is limited in Indonesia. Alternatively, autograft needs to be folded several times for sufficient thickness but it will be shorter and only applicable for the inside-out method. We present a case of PCL reconstruction using a double adjustable button fixation with the outside-in tibia tunneling method. Case Presentation: A fifty-five-year-old male came to our office with an unstable right knee after he fell 1 month ago. Physical examination showed positive posterior drawer and mild right knee effusion, other findings were normal. MRI revealed a total PCL rupture. Two weeks later, the PCL reconstruction was done using autograft from gracillis and semitendinous. A large adjustable button was placed on the tibia tunnel, using the outside-in technique. Knee was stable postoperatively. Discussion: PCL reconstruction using double adjustable buttons was chosen to accommodate larger but shorter autografts. The outside-in tibial tunnel has less risk of graft laxity less expensive and more simple technically compared to inside-out adjustable button tunnel. Conclusion: Tibial fixation using an adjustable large button should be considered in PCL reconstruction with short autograft.

scholarly journals Three-Dimensional Reconstruction Computed Tomography Evaluation of the Tunnel Location and Angle during Anatomic Single-Bundle Anterior Cruciate Ligament Reconstruction

2017 ◽  
Vol 5 (2_suppl2) ◽  
pp. 2325967117S0009
Author(s):  
Sang Hak Lee ◽  
Kyung Hk Yoon ◽  
Chan Il Bae
Keyword(s):  
Acl Reconstruction ◽  
Femoral Tunnel ◽  
Cruciate Ligament ◽  
Tibial Tunnel ◽  
Posterior Wall ◽  
Width Ratio ◽  
Single Bundle ◽  
Tunnel Length ◽  
Tunnel Position ◽  
The Mean

Purpose: Tibial tunnel-independent drilling has attracted increased interest in recent years for anatomic anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to compare the geometry and position of the femoral tunnel between the anteromedial portal (AMP) and outside-in (OI) techniques after anatomic single-bundle ACL reconstruction. Methods: We prospectively evaluated 82 patients undergoing single-bundle ACL reconstruction with hamstring tendon autografts using either the AMP (n=40) or OI (n=42) technique. The locations of the tibial and femoral tunnel apertures were assessed by immediate postoperative 3-dimensional computed tomography (3D CT) imaging with OsiriX imaging software. The femoral graft bending angle, femoral tunnel aperture shape (height/width ratio), femoral tunnel length, and posterior wall breakage were also measured. Results: The two techniques did not differ significantly in the femoral tunnel position perpendicular to the Blumensaat line. However, the mean femoral tunnel position parallel to the Blumensaat line was more caudally positioned in the AMP group than in the OI group (P=0.025) The two groups did not differ significantly in tibial tunnel position. The mean femoral tunnel length did not differ between the AMP (36.1±0.33 mm) and OI groups (35.6±0.37 mm; P=0.548) The mean femoral graft angle in the OI group (99.6°±7.1°) was significantly more acute than that of the AMP group (108.9°±10.2°) (p < 0.0001). The mean height/width ratio of the AMP group (1.21±0.20) was significantly more ellipsoidal than that of the OI group (1.07±0.09) (p < 0.0001). Posterior wall breakage was detected in 3 cases (7.5%), all in the AMP group. Conclusions: After single-bundle anatomic ACL reconstruction, 3D CT showed a significantly shallower femoral tunnel in the AMP group than in the OI group. The AMP group had a more ellipsoidal femoral tunnel with a risk of posterior wall breakage than the OI group. The OI group showed a more acute bending angle of the femoral tunnel than the AMP group. [Figure: see text][Figure: see text]

Tibial Slope Strongly Influences Knee Stability After Posterior Cruciate Ligament Reconstruction: A Prospective 5- to 15-Year Follow-up

2016 ◽  
Vol 45 (2) ◽  
pp. 355-361 ◽  
Author(s):  
Clemens Gwinner ◽  
Andreas Weiler ◽  
Manoussos Roider ◽  
Frederik M. Schaefer ◽  
Tobias M. Jung
Keyword(s):  
Posterior Cruciate Ligament ◽  
Sagittal Plane ◽  
Cruciate Ligament ◽  
Tibial Slope ◽  
Posterolateral Corner ◽  
Knee Stability ◽  
Pcl Reconstruction ◽  
The Mean ◽  
Tibial Translation

Background: The reported failure rate after posterior cruciate ligament (PCL) reconstruction remains high. Previous studies have shown that the tibial slope (TS) influences sagittal plane laxity. Consequently, alterations of TS might have an effect on postoperative knee stability after PCL reconstruction. Hypothesis: We hypothesized that flattening of TS is associated with increased posterior laxity after PCL reconstruction. Study Design: Cohort study; Level of evidence 3. Methods: This study consisted of 48 patients who underwent PCL reconstruction in a single-surgeon series. Eight patients underwent an isolated PCL reconstruction, 27 patients underwent an additional posterolateral corner reconstruction, and 13 patients underwent a combined reconstruction of the PCL, anterior cruciate ligament, and posterolateral corner. Three blinded observers measured TS and the side-to-side difference (SSD) of posterior tibial translation (PTT) before and after PCL reconstruction using standardized stress radiographs. The minimum follow-up was 5 years. Results: At a mean follow-up of 103 months (range, 65-187), the mean SSD of PTT was significantly reduced (10.9 ± 2.9 vs 4.9 ± 4.3 mm; P < .0001). The mean TS was 8.0° ± 3.7° (range, 1°-14.3°) for the operated knee and 7.9° ± 3.2° (range, 2°-15.3°) for the contralateral knee. There was a statistically significant correlation between TS and PTT ( r = −0.77 and R2 = 0.59; P < .0001). In addition, there was a significant correlation between TS and the postoperative reduction of PTT ( r = 0.74 and R2 = 0.55; P < .0001). Subgrouping according to the number of operated ligaments showed no significant differences regarding TS or the mean reduction of PTT. Conclusion: Flattening of TS is associated with a significantly higher remaining PTT as well as a lower reduction of PTT. Notably, these results are irrespective of sex and number of ligaments addressed. Thus, isolated soft tissue procedures in PCL deficiency may only incompletely address posterior knee instability in patients with flattening of the posterior slope.

Comparison of Acorn and Fluted Reamers on Tibial Tunnel Outer Aperture Dimensions in Anterior Cruciate Ligament Reconstruction

2020 ◽  
Author(s):  
Adam D. Gerrard ◽  
Chris M. Jump ◽  
Paul Sutton ◽  
Charalambos P. Charalambous
Keyword(s):  
Anterior Cruciate Ligament ◽  
Acl Reconstruction ◽  
Ligament Reconstruction ◽  
Cruciate Ligament ◽  
Tibial Tunnel ◽  
Aperture Width ◽  
The Mean ◽  
Anterior Cruciate ◽  
Degree Deviation ◽  
Substantial Change

AbstractThe aim of this study was to determine if the type of reamer used in tibial tunnel creation during anterior cruciate ligament (ACL) reconstruction influences the dimensions of the tunnel's outer aperture. Tibial tunnels were created in tibial saw bones by reaming over a guidewire using an 8 mm acorn or fluted reamer in an antegrade manner. Reaming was aimed either in line with the guidewire, or with 10-degree inferior/superior deviation in relation to the wire. The shape and size of the outer aperture of the tibial tunnel were compared between the two reamers. When using the acorn reamer, a 10-degree deviation in relation to the guidewire resulted in minimal change in outer aperture length (mean 13.6 vs. 15.6 mm, p = 0.11) and width (11.6 vs. 11.1 mm, p = 0.51). However, when using the fluted reamer, although the aperture width showed no substantial change with reamer/guidewire deviation (11.4 vs. 11.2 mm, p = 0.71), the mean length almost doubled (14.7 vs. 28.1 mm, p = 0.002). The use of a fluted reamer when reaming the tibial tunnel creates a distal aperture which is inconsistently sized, larger, and of oblong shape compared with an acorn-shaped reamer. This should be taken in consideration when using a fluted reamer for creating the tibial tunnel in ACL reconstruction.

Modeling of engineering properties for predicting the mass of acid lime fruit (Citrus aurantifolia Swingle)

2020 ◽  
Vol 44 (01) ◽  
pp. 20-28
Author(s):  
V. S. Sonone ◽  
D. A. Pawar ◽  
V. P. Kad ◽  
P. A. Unde
Keyword(s):  
Surface Area ◽  
Geometric Mean ◽  
Engineering Properties ◽  
Mean Values ◽  
Mean Diameter ◽  
Multiple Variable ◽  
Acid Lime ◽  
The Mean ◽  
Packaging Industry ◽  
Area And Volume

Engineering properties and their relationships with mass for Phule Sharbati acid lime cultivar were investigated. Relationship between physical properties of fruits and its mass will create tremendous change in the packaging industry. The mean values of engineering properties such as minor diameter, intermediate diameter, major diameter, geometric mean diameter, sphericity, aspect ratio, mass, surface area, volume and true density were found to be 42.55 mm, 41.20 mm, 40.41 mm, 0.94, 0.94, 38.17g, 49997 mm2, 33322.8 mm3 and 1 g/cc, respectively. Regression models were used to predict the effect of mass of acid lime and classified into two: 1–Single and multiple variable regressions of acid lime mass and dimensional characteristics and 2- Single variable regression for geometric mean diameter, sphericity, surface area and volume. Results indicated that mass modeling of acid lime based on minor diameter was found most appropriate in the first classification. In the second classification, the power-law model was noticed best on the basis of the geometric mean diameter, surface area and the volume.

Correlation Between Endobutton Loop Length and Tunnel Widening After Hamstring Anterior Cruciate Ligament Reconstruction

2012 ◽  
Vol 41 (1) ◽  
pp. 101-106 ◽  
Author(s):  
Nam-Hong Choi ◽  
Jong-Seok Oh ◽  
Seok-Hyun Jung ◽  
Brian N. Victoroff
Keyword(s):  
Femoral Tunnel ◽  
Cruciate Ligament ◽  
Tibial Tunnel ◽  
Pivot Shift Test ◽  
Tunnel Widening ◽  
Significant Difference ◽  
Kt 1000 ◽  
The Mean ◽  
Anterior Cruciate ◽  
Tegner Activity Scale

Background: Previous reports have shown that graft fixation with the Endobutton is associated with tunnel widening because it provides distant fixation rather than aperture fixation. Hypothesis: A longer loop of the Endobutton results in greater tunnel widening than a shorter loop. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 171 consecutive patients underwent hamstring anterior cruciate ligament (ACL) reconstruction fixed with the Endobutton. They were followed for a minimum of 2 years postoperatively. A 15-mm loop was used in 20 patients, a 20-mm loop in 53, a 25-mm loop in 58, and a >30-mm loop in 40. On anterior-posterior (AP) and lateral radiographs, the measured diameters of the femoral tunnel at 2 years after surgery were compared with the diameter of the reamer used at surgery. The measured diameter of the tibial tunnel at 2 years after surgery was compared with measurements taken on the immediate postoperative day. The center of the tibial tunnel and direction of the ACL graft were also measured. Postoperative knee stability was evaluated using the Lachman test, pivot-shift test, and KT-1000 arthrometer. Functional evaluations were performed using the Lysholm score and Tegner activity scale. All measurements were compared among the 4 groups according to the length of the Endobutton loop. Results: The mean ± standard deviation (SD) diameter of the femoral tunnel increased by 50.7% ± 23.3% and 37.0% ± 18.8% on AP and lateral radiographs at 2 years after surgery, respectively. The mean ± SD diameter of the tibial tunnel increased by 40.8% ± 19.3% and 46.4% ± 22.6% on AP and lateral radiographs, respectively. No significant difference in tunnel widening was present according to the length of the Endobutton loop. There were no significant differences in the average center of the tibial tunnel or the average angle of the direction of the ACL graft among the 4 groups. There was no significant difference in Lachman test results, postoperative KT-1000 arthrometer side-to-side differences, Lysholm score, and Tegner activity scale score among the 4 groups. The group with a >30-mm loop showed a significant difference in the pivot-shift test than the other 3 groups ( P = .023). Conclusion: A longer Endobutton loop did not result in greater tunnel widening than a shorter loop. Long fixation distance may not be associated with tunnel widening after hamstring ACL reconstructions.

Minecraft Comes to Math Class

2018 ◽  
Vol 23 (6) ◽  
pp. 334-341 ◽  
Author(s):  
Kimberly Moore
Keyword(s):  
Surface Area ◽  
Three Dimensional ◽  
Eighth Grade ◽  
Eighth Grade Students ◽  
The Creation ◽  
Math Class ◽  
Area And Volume

Eighth-grade students use a character from Minecraft® to explore surface area and volume, resulting in the creation of a three-dimensional “Cylindrical Steve.”

Investigation of factors related to the occurrence of osteochondral lesions of the talus by 3D bone morphology of the ankle

2018 ◽  
Vol 100-B (11) ◽  
pp. 1487-1490 ◽  
Author(s):  
A. Teramoto ◽  
H. Shoji ◽  
H. Kura ◽  
Y. Sakakibara ◽  
T. Kamiya ◽  
...  
Keyword(s):  
Surface Area ◽  
Osteochondral Lesion ◽  
Opening Angle ◽  
Control Group ◽  
Osteochondral Lesions ◽  
Medial Malleolus ◽  
3D Ct ◽  
Bone Morphology ◽  
The Mean ◽  
Area And Volume

Aims The aims of this study were to evaluate the morphology of the ankle in patients with an osteochondral lesion of the talus using 3D CT, and to investigate factors that predispose to this condition. Patients and Methods The study involved 19 patients (19 ankles) who underwent surgery for a medial osteochondral lesion (OLT group) and a control group of 19 healthy patients (19 ankles) without ankle pathology. The mean age was significantly lower in the OLT group than in the control group (27.0 vs 38.9 years; p = 0.02). There were 13 men and six women in each group. 3D CT models of the ankle were made based on Digital Imaging and Communications in Medicine (DICOM) data. The medial malleolar articular and tibial plafond surface, and the medial and lateral surface area of the trochlea of the talus were defined. The tibial axis-medial malleolus (TMM) angle, the medial malleolar surface area and volume (MMA and MMV) and the anterior opening angle of the talus were measured. Results The mean TMM angle was significantly larger in the OLT group (34.2°, sd 4.4°) than in the control group (29.2°, sd 4.8°; p = 0.002). The mean MMA and MMV were significantly smaller in the OLT group than in the control group (219.8 mm2, sd 42.4) vs (280.5 mm2, sd 38.2), and (2119.9 mm3, sd 562.5) vs (2646.4 mm3, sd 631.4; p < 0.01 and p = 0.01, respectively). The mean anterior opening angle of the talus was significantly larger in the OLT group than in the control group (15.4°, sd 3.9°) vs (10.2°, sd 3.6°; p < 0.001). Conclusion 3D CT measurements showed that, in patients with a medial osteochondral lesion of the talus, the medial malleolus opens distally, the MMA and MMV are small, and the anterior opening angle of the talus is large. This suggests that abnormal morphology of the ankle predisposes to the development of osteochondral lesions of the talus. Cite this article: Bone Joint J 2018;100-B:1487–90.

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