scholarly journals Length change pattern of the medial structures of the knee and related reconstructions

2020 ◽  
Vol 8 (9_suppl7) ◽  
pp. 2325967120S0053
Author(s):  
Arne Olbrich ◽  
Elmar Herbst ◽  
Christoph Domnick ◽  
Johannes Glasbrenner ◽  
Michael J. Raschke ◽  
...  

Introduction: Aim of the study was to investigate the length changes of the medial structures and related reconstructions. It was assumed that the three fibre sections (anterior/middle/posterior) of the superficial medial collateral ligament (sMCL) have different length change patterns, which cannot be imitated by current reconstructions. Hypotheses: The three fibre sections (anterior/middle/posterior) of the superficial medial collateral ligament (sMCL) cannot be imitated by current reconstructions. Methods: Measurements were made on eight cadaveric knees. The knee joints were clamped in a custom-made open chain extension structure. For this purpose, the portions of the quadriceps and the iliotibial tract were aligned according to their fibre direction and statically loaded using hanging weights. The respective tibial and femoral insertion points of the sMCL anterior/middle/posterior fibres were marked by small pins. Similarly, pins were inserted at the tibial and femoral attachment sites of the posterior oblique ligament (POL). In order to imitate the Lind reconstruction, a pin was additionally inserted on the tibial semitendinosus insertion site. Pin combinations accounting for the anterior/middle/posterior sMCL, the POL, and the Lind reconstruction were connected using a high resistant suture. Then the length change patterns were measured using a rotary encoder from 0-120° knee flexion. Statistical analysis was performed using 2-way repeated-measures ANOVA and a post-hoc Bonferroni correction (p <0.05). Results: The anterior and posterior fibres of the sMCL showed a reciprocal behaviour (p< 0.001). The anterior fibres showed a length reduction (2%) up to a flexion of 20°, followed by an elongation of 5% at 120° flexion, which means that the anterior fibres are tight in knee flexion. Conversely, the posterior fibres of the MCL showed an initial length reduction of 4% at 20° flexion. This was followed by an isometric range (20° - 80°) and a further length reduction of 8% in deep flexion (120°). Thus, the posterior fibres of the MCL were tight in extension. The three parts of the POL showed a constant reduction of 25% between 0° and 120°. The Lind reconstruction with the tibial pin at the semitendinosus insertion site showed similar length changes compared to the sMCL (n.s.). Furthermore, the Lind reconstruction was dependent on the femoral placement of the pins (p <.001). The tibial placement had no significant influence. Conclusion: The anterior portion of the sMCL was tight in flexion, whereas the posterior portion was tight in extension. This reciprocal behavior could not be imitated by a single point to point reconstruction. When surgically applying these reconstructions, special attention should be paid to the femoral insertion.

Author(s):  
Christoph Kittl ◽  
James Robinson ◽  
Michael J. Raschke ◽  
Arne Olbrich ◽  
Andre Frank ◽  
...  

Abstract Purpose The purpose of this study was to examine the length change patterns of the native medial structures of the knee and determine the effect on graft length change patterns for different tibial and femoral attachment points for previously described medial reconstructions. Methods Eight cadaveric knee specimens were prepared by removing the skin and subcutaneous fat. The sartorius fascia was divided to allow clear identification of the medial ligamentous structures. Knees were then mounted in a custom-made rig and the quadriceps muscle and the iliotibial tract were loaded, using cables and hanging weights. Threads were mounted between tibial and femoral pins positioned in the anterior, middle, and posterior parts of the attachment sites of the native superficial medial collateral ligament (sMCL) and posterior oblique ligament (POL). Pins were also placed at the attachment sites relating to two commonly used medial reconstructions (Bosworth/Lind and LaPrade). Length changes between the tibiofemoral pin combinations were measured using a rotary encoder as the knee was flexed through an arc of 0–120°. Results With knee flexion, the anterior fibres of the sMCL tightened (increased in length 7.4% ± 2.9%) whilst the posterior fibres slackened (decreased in length 8.3% ± 3.1%). All fibre regions of the POL displayed a uniform lengthening of approximately 25% between 0 and 120° knee flexion. The most isometric tibiofemoral combination was between pins placed representing the middle fibres of the sMCL (Length change = 5.4% ± 2.1% with knee flexion). The simulated sMCL reconstruction that produced the least length change was the Lind/Bosworth reconstruction with the tibial attachment at the insertion of the semitendinosus and the femoral attachment in the posterior part of the native sMCL attachment side (5.4 ± 2.2%). This appeared more isometric than using the attachment positions described for the LaPrade reconstruction (10.0 ± 4.8%). Conclusion The complex behaviour of the native MCL could not be imitated by a single point-to-point combination and surgeons should be aware that small changes in the femoral MCL graft attachment position will significantly effect graft length change patterns. Reconstructing the sMCL with a semitendinosus autograft, left attached distally to its tibial insertion, would appear to have a minimal effect on length change compared to detaching it and using the native tibial attachment site. A POL graft must always be tensioned near extension to avoid capturing the knee or graft failure.


2020 ◽  
Vol 28 (12) ◽  
pp. 3720-3732 ◽  
Author(s):  
Lukas Willinger ◽  
Shun Shinohara ◽  
Kiron K. Athwal ◽  
Simon Ball ◽  
Andy Williams ◽  
...  

Abstract Purpose To define the length-change patterns of the superficial medial collateral ligament (sMCL), deep MCL (dMCL), and posterior oblique ligament (POL) across knee flexion and with applied anterior and rotational loads, and to relate these findings to their functions in knee stability and to surgical repair or reconstruction. Methods Ten cadaveric knees were mounted in a kinematics rig with loaded quadriceps, ITB, and hamstrings. Length changes of the anterior and posterior fibres of the sMCL, dMCL, and POL were recorded from 0° to 100° flexion by use of a linear displacement transducer and normalised to lengths at 0° flexion. Measurements were repeated with no external load, 90 N anterior draw force, and 5 Nm internal and 5 Nm external rotation torque applied. Results The anterior sMCL lengthened with flexion (p < 0.01) and further lengthened by external rotation (p < 0.001). The posterior sMCL slackened with flexion (p < 0.001), but was lengthened by internal rotation (p < 0.05). External rotation lengthened the anterior dMCL fibres by 10% throughout flexion (p < 0.001). sMCL release allowed the dMCL to become taut with valgus rotation (p < 0.001). The anterior and posterior POL fibres slackened with flexion (p < 0.001), but were elongated by internal rotation (p < 0.001). Conclusion The structures of the medial ligament complex react differently to knee flexion and applied loads. Structures attaching posterior to the medial epicondyle are taut in extension, whereas the anterior sMCL, attaching anterior to the epicondyle, is tensioned during flexion. The anterior dMCL is elongated by external rotation. These data offer the basis for MCL repair and reconstruction techniques regarding graft positioning and tensioning.


2009 ◽  
Vol 37 (9) ◽  
pp. 1762-1770 ◽  
Author(s):  
Chad J. Griffith ◽  
Robert F. LaPrade ◽  
Steinar Johansen ◽  
Bryan Armitage ◽  
Coen Wijdicks ◽  
...  

Background There is a lack of knowledge on the primary and secondary static stabilizing functions of the posterior oblique ligament (POL), the proximal and distal divisions of the superficial medial collateral ligament (sMCL), and the meniscofemoral and meniscotibial portions of the deep medial collateral ligament (MCL). Hypothesis Identification of the primary and secondary stabilizing functions of the individual components of the main medial knee structures will provide increased knowledge of the medial knee ligamentous stability. Study Design Descriptive laboratory study. Methods Twenty-four cadaveric knees were equally divided into 3 groups with unique sequential sectioning sequences of the POL, sMCL (proximal and distal divisions), and deep MCL (meniscofemoral and meniscotibial portions). A 6 degree of freedom electromagnetic tracking system monitored motion after application of valgus loads (10 N·m) and internal and external rotation torques (5 N·m) at 0°, 20°, 30°, 60°, and 90° of knee flexion. Results The primary valgus stabilizer was the proximal division of the sMCL. The primary external rotation stabilizer was the distal division of the sMCL at 30° of knee flexion. The primary internal rotation stabilizers were the POL and the distal division of the sMCL at all tested knee flexion angles, the meniscofemoral portion of the deep MCL at 20°, 60°, and 90° of knee flexion, and the meniscotibial portion of the deep MCL at 0° and 30° of knee flexion. Conclusion An intricate relationship exists among the main medial knee structures and their individual components for static function to applied loads. Clinical Significance: Interpretation of clinical knee motion testing following medial knee injuries will improve with the information in this study. Significant increases in external rotation at 30° of knee flexion were found with all medial knee structures sectioned, which indicates that a positive dial test may be found not only for posterolateral knee injuries but also for medial knee injuries.


2020 ◽  
Vol 8 (5_suppl4) ◽  
pp. 2325967120S0031
Author(s):  
Christoph Kittl ◽  
Arne Olbrich ◽  
Michael J. Raschke ◽  
Christoph Domnick ◽  
Johannes Glasbrenner ◽  
...  

Aims and Objectives: Chronic medial instability presents a severe problem both for the patient and the surgeon, and may result into anterior cruciate ligament graft failure in a combined anteromedial instability. Thus, reconstructions have been developed to conquer this problem. However, these are not capable of mimicking the flat anatomy of the medial structures of the knee. The goal of the present study was to examine the length change patterns of the native medial structures of the knee and their related reconstructions. It was hypothesised that the different portions of the medial collateral ligament present different length change patterns, which cannot be imitated by current reconstructions. Materials and Methods: Eight cadaveric knees were dissected of skin and subcutaneous fat. The satorius fascia was removed to get a clear vision of the medial structures. The knee was then mounted in a rig and the quadriceps muscle and the iliotibial tract were loaded, using cables and hanging weights, according to its fiber orientations and cross-sections. Threads attached to three tibial pins at the anterior/middle/posterior portion of the medial collateral ligament (MCL) were then guided to three femoral eyelets at the anterior/middle/posterior portion of the femoral MCL insertion and analogous with the tibial/femoral posterior oblique ligament (POL) insertion. A tibial pin was also put at the semitendinosus insertion to imitate the Lind reconstruction. Between 0-120 degree knee flexion, the distances between each possible tibiofemoral combination were measured using a linea variable differential transformer (LVDT). Statistical analysis was performed using two way repeated measurements ANOVA. Results: The anterior MCL showed an initial slackening (2%) until 20° flexion, followed by a tightening (5%) towards deep flexion (120°), meaning that it is tight in flexion. The posterior MCL also showed an initial slackening (4%) until 20° of flexion. However, then followed by an isometric area (20-80°) and a further slackening (8%) towards deep flexion (120°), meaning that it is tight in extension. The three portions of the POL showed a linear slackening between 0-120° (25%). The middle MCL showed a sine wave behaviour, slackening from 0- 60° (3%) and tightening between 60-100° (1%). This behaviour was similar in the Lind and Robinson reconstruction, which were the most isometric tibiofemoral combinations (total strain range: 5,3 ± 2,1). The native POL length changes showed the most non-isometric behaviour resulting into a total strain range of 28,8 ± 6,2, which was significantly different from the native MCL and MCL reconstructions (p< .001) Conclusion: The anterior, middle, and posterior parts of the MCL showed different length change patterns. The anterior part tightened in flexion, whereas the posterior part tightened in extension. This behavior could not be reproduced by the current reconstructions, such as the Lind and Robinson procedure, which only could imitate the middle portion of the native MCL.


2020 ◽  
Vol 2 (2) ◽  
pp. e153-e159
Author(s):  
Michael A. Gaudiani ◽  
Derrick M. Knapik ◽  
Matthew W. Kaufman ◽  
Michael J. Salata ◽  
James E. Voos ◽  
...  

2020 ◽  
Vol 48 (6) ◽  
pp. 1398-1405
Author(s):  
Adam B. Yanke ◽  
Hailey P. Huddleston ◽  
Kevin Campbell ◽  
Michael L. Redondo ◽  
Alejandro Espinoza ◽  
...  

Background: Patella alta has been identified as an important risk factor for lateral patellar instability and medial patellofemoral complex (MPFC) reconstruction failure. Purpose: To evaluate the length changes of the MPFC at multiple possible reconstruction locations along the extensor mechanism in varying degrees of patella alta throughout knee motion. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen cadaveric knees were used in this study. The MPFC was identified and dissected with the patellar tendon and quadriceps tendon. A custom-made jig was utilized to evaluate lengths from 0° to 90° of flexion with physiological quadriceps loading. Length was measured with a 3-dimensional robotic arm at 4 possible reconstruction locations along the extensor mechanism: the midpoint patella (MP), the MPFC osseous center (FC), the superior medial pole of the patella (SM) at the level of the quadriceps insertion, and 1 cm proximal to the SM point along the quadriceps tendon (QT). These measurements were repeated at 0°, 20°, 40°, 60° and 90° of flexion. Degrees of increasing severity of patella alta at Caton-Deschamps index (CDI) ratios of 1.0, 1.2, 1.4, and 1.6 were then investigated. Results: Patella alta and MPFC attachment site location significantly affected changes in MPFC length from 0° to 90° of flexion ( P< .0005). Length changes at attachment MP showed no difference when CDI 1.0 was compared with all patella alta values (CDI 1.2, 1.4, 1.6; P > .05). Similarly, FC showed no difference in length change from 0° to 90° until CDI 1.6, in contrast to proximal attachments (SM, QT), which demonstrated significant changes at CDI 1.4 and 1.6. When length changes were analyzed at each degree of flexion (0°, 20°, 40°, 60°, 90°), Spearman correlation analysis showed a moderate negative linear correlation for QT at CDI 1.0 ( r= −0.484; P = .002) and 1.6 ( r = −0.692; P < .0005), demonstrating constant loosening at the QT point at normal and elevated patellar height. In contrast, no differences in length were observed for MP at CDI 1.0 throughout flexion, and at CDI 1.6, there was a difference only at 0° ( P < .05). Points FC and MP at CDI 1.6 had similar length change properties to points SM and QT at CDI 1.0 ( P > .05), suggesting that distal attachments in the setting of patella alta may provide similar length changes to proximal attachmentswith normal height. Conclusion: Anisometry of the MPFC varies not only with attachment location on the extensor mechanism but also with patellar height. Increased patellar height leads to more significant changes in anisometry in the proximal MPFC attachment point as compared with the distal component. In the setting of patella alta, including a CD ratio of 1.6, the osseous attachments of the MPFC remain nearly isometric wheras the proximal half length changes increase significantly. Clinical Significance: The results of this study support the idea that the MPFC should be considered as 2 separate entities (proximal medial quadriceps tendon femoral ligament and distal medial patellofemoral ligament) owing to their unique length change properties.


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