Background:
Combined injury of the anterior cruciate ligament (ACL) and the medial collateral ligament (MCL) is a common injury pattern and accounts for 20% of all ligamentous knee injuries. Despite ...advancements in surgical technique, there is no up-to-date consensus regarding the superiority of nonoperative versus operative management in higher-grade MCL tears of combined ACL-MCL injuries.
Purpose:
To interpret recent literature on treatment options and to provide an updated evidence-based approach for management of combined ACL-MCL knee injuries.
Study Design:
Systematic review and meta-analysis; Level of evidence, 4.
Methods:
We performed a systematic review on outcomes following treatment of concomitant ACL and MCL injuries. A computerized search was conducted in PubMed, Embase.com, and Scopus.com. Authors independently assessed eligible studies and screened titles and abstracts. Articles reporting on patients with concomitant ACL and MCL injuries with or without concomitant procedures were included. Data regarding study design, sample size, patient age and sex, length of follow-up, timing of surgery, indications, surgical methods, concomitant procedures, outcomes, and complications were recorded. Patient-reported outcomes (PROs) and functional outcomes, including Knee injury and Osteoarthritis Outcome Score, International Knee Documentation Committee scores, Lysholm and Tegner scores, and range of motion, were estimated via meta-analysis and compared statistically by surgical approach.
Results:
In total, 18 studies were included in the systematic review with level 1 to level 4 evidence, with a total of 1,534 cases, were included in the systematic review. Of these, 16 studies with sufficient statistical reporting including 997 cases with sufficient follow-up were included in meta-analysis. Three different approaches to combined ACL-MCL injuries were identified: ACL reconstruction with (1) nonoperative MCL, (2) MCL repair, and (3) MCL reconstruction. There was no statistical difference between nonoperative versus surgically managed MCL injuries for PROs, range of motion at final follow up, or quadriceps strength.
Conclusion:
Reconstruction of combined injury in a delayed fashion facilitates return of range of motion and may allow time for low-grade MCL tears to heal. If residual valgus or anteromedial rotatory laxity remains after a period of rehabilitation, then concomitant surgical management of ACL and MCL injuries is warranted. Avulsion MCL injuries and Stener-type lesions may benefit from early repair techniques.
To evaluate the radiographic and clinical follow-up results of iatrogenic medial collateral ligament (MCL) injuries caused by valgus stress during arthroscopic surgery of the knee.
This study ...retrospectively evaluated 15 knees in 15 patients (8 female and 7 male patients), with a mean age of 58 years (range, 45-66 years), with iatrogenic MCL injuries caused by valgus stress during arthroscopic surgery of the knee. All patients were treated conservatively without an immobilizer or brace. The mean follow-up period was 24 months (range, 18-51 months). Evaluations included magnetic resonance imaging immediately postoperatively, as well as physical examinations and valgus stress radiographs (at 0° and 30° of knee flexion) 6 weeks after surgery and at final follow-up.
Postoperative magnetic resonance imaging in all patients showed increased signal intensity, swelling, and partial loss of continuity at the meniscofemoral portion of the MCL. Physical examination showed mild tenderness in only 1 patient after 6 weeks and none at final follow-up. Valgus stress tests and valgus stress radiographs showed no significant differences between the injured and uninjured knees at 6 weeks postoperatively and at final follow-up (P > .05).
Iatrogenic MCL injuries during arthroscopic knee surgery could be treated successfully without a splint or brace.
Level IV, prognostic case series.
Purpose
The purpose of this study was to evaluate and compare knee kinematics and kinetics following either single bundle, modified triangular or double-bundle reconstruction of the superficial ...medial collateral ligament (sMCL) with single bundle anatomic ACL reconstruction.
Methods
Using a cadaveric model (
n
= 10), the knee kinematics and kinetics following three MCL reconstructions (single-bundle (SB), double-bundle (DB), modified triangular) with single bundle anatomic ACL reconstruction were compared with the intact and deficient knee state. The knees were tested under (1) an 89-N anterior tibial load, (2) 5 N-m internal and external rotational tibial torques, and (3) a 7 N-m valgus torque.
Results
Anatomic ACL reconstruction with SB MCL reconstruction was able to restore anterior tibial translation and external rotation to intact knee values but failed to the internal and valgus rotatory stability. Anatomical DB MCL reconstruction (with SB ACL reconstruction) and the modified triangular MCL reconstruction (with SB ACL reconstruction) restored all knee kinematics to the intact value.
Conclusion
This study shows that clinical presentation with combined ACL and severe sMCL injury, single-bundle MCL with single-bundle ACL reconstruction does not restore knee kinematics. Anatomical double-bundle MCL reconstruction may produce slightly better biomechanical stability than the modified triangular MCL reconstruction, but the modified triangular reconstruction might be more clinically practical with the advantages of being less invasive and technically simpler while at the same time can restore a nearly normal knee joint.
Medial collateral ligament (MCL) pie-crusting technique in total knee arthroplasty (TKA) is one of the methods of medial release. The effects and risks of blade pie-crusting have been reported in ...previous studies. However, only a few have reported the safety and efficacy of needle pie-crusting. In this cadaveric study, we quantitatively evaluated the amount of gap change by MCL needle pie-crusting. We investigated five knees of four fresh human cadavers and performed posterior-stabilized TKA. Only deep MCL release as the medial release was conducted. We punctured the MCL from the deep layer to the superficial layer using a 18 G needle in a 90-degree flexion position for 0, 10, 20, 50, 75, and 100 times. Medial and lateral gaps were measured accurately with a balancer at determined times in 0 and 90-degree flexion positions. Changes in medial and lateral gaps were not significant differences in flexion and extension position. However, in 90-degree flexion, medial gap changes were tended to be larger than lateral gap changes. A 0.6 mm additional medial release and a 0.2 mm additional lateral release were found per 10 times pie crust in flexion position (100 times,
: 0.08). However, large differences existed among the cases. Needle pie-crusting is safer than blade pie-crusting because of the small efficacy of one-time pie crust. MCL needle pie-crusting showed varied effects for each case. This result indicates the risk of relaxation of an unexpected gap. Caution should be taken when choosing between needle pie-crusting and blade pie-crusting.
The purpose of this study was to evaluate and compare knee kinematics and stability following either triangular or anatomical reconstruction of the superficial medial collateral ligament (sMCL) and ...posterior oblique ligament (POL).
In a cadaveric model (12 knees), the stability and kinematics following two experimental sMCL and POL reconstructions were compared in sMCL- and POL-deficient knees versus normal knees. The first reconstruction was a triangular reconstruction of the sMCL and POL, while the second involved an anatomical reconstruction of the sMCL and POL. All knees were tested through four different states. The changes in valgus angles, external rotation, and internal rotation were measured in the normal and sMCL- and POL-deficient knees, as well as in the knees that had undergone the two different forms (triangular and anatomical) of reconstruction.
After initial sectioning of the sMCL and POL, we observed significantly increased valgus rotation, external rotation, and internal rotation at all knee flexion angles (0°, 20°, 30°, 60°, 90°). Additionally, passive stability testing demonstrated a significant increase in tibial internal rotation following triangular reconstruction compared with anatomical reconstruction at knee flexion angles of 20° and 30°. A significant increase in internal rotation was present following triangular reconstruction compared with anatomical reconstruction at 20° (mean difference = 2.77) (P = 0.008) and 30° (mean difference = 0.99) (P < 0.001) of knee flexion.
This study suggests that anatomical sMCL and POL reconstruction produces slightly better biomechanical stability than triangular reconstruction. However, triangular reconstruction may restore a near-normal knee joint is both less invasive and more practical.
Background:
There is little evidence of the biomechanical performance of medial collateral ligament (MCL) reconstructions for restoring stability to the MCL-deficient knee regarding valgus, external ...rotation (ER), and anteromedial rotatory instability (AMRI).
Hypothesis:
A short isometric reconstruction will better restore stability than a longer superficial MCL (sMCL) reconstruction, and an additional deep MCL (dMCL) graft will better control ER and AMRI than single-strand reconstructions.
Study Design:
Controlled laboratory study.
Methods:
Nine cadaveric human knees were tested in a kinematics rig that allowed tibial loading while the knee was flexed-extended 0° to 100°. Optical markers were placed on the femur and tibia and displacements were measured using a stereo camera system. The knee was tested intact, and then after MCL (sMCL + dMCL) transection, and loaded in anterior tibial translation (ATT), ER, varus-valgus, and combined ATT + ER (AMRI loading). Five different isometric MCL reconstructions were tested: isolated long sMCL, a short construct, each with and without dMCL addition, and isolated dMCL reconstruction, using an 8 mm–wide synthetic graft.
Results:
MCL deficiency caused an increase in ER of 4° at 0° of flexion (P = .271) up to 14° at 100° of flexion (P = .002), and valgus laxity increased by 5° to 8° between 0° and 100° of flexion (P < .024 at 0°-90°). ATT did not increase significantly in isolated MCL deficiency (P > .999). All 5 reconstructions restored native stability across the arc of flexion apart from the isolated long sMCL, which demonstrated residual ER instability (P≤ .047 vs other reconstructions).
Conclusion:
All tested techniques apart from the isolated long sMCL graft are satisfactory in the context of restoring the valgus, ER, and AMRI stability to the MCL-deficient knee in a cadaveric model.
Clinical Relevance:
Contemporary MCL reconstruction techniques fail to control ER and therefore AMRI as they use a long sMCL graft and do not address the dMCL. This study compares 5 MCL reconstruction techniques. Both long and short isometric constructs other than the long sMCL achieved native stability in valgus and ER/AMRI. Double-strand reconstructions (sMCL + dMCL) tended to provide more stability. This study shows which reconstructions demonstrate the best biomechanical performance, informs surgical reconstruction techniques for AMRI, and questions the efficacy of current popular techniques.
Background:
Semitendinosus and gracilis muscles are frequently harvested for autologous tendon grafts for cruciate ligament reconstruction. This study investigated the joint-stabilizing effects of ...these hamstring muscles in cases of insufficiency of the medial collateral ligament (MCL).
Hypotheses:
First, both the semitendinosus and gracilis muscles can actively stabilize the joint against valgus moments in the MCL-deficient knee. Second, the stabilizing influence of these muscles decreases with an increasing knee flexion angle.
Study Design:
Controlled laboratory study.
Methods:
The kinematics was examined in 10 fresh-frozen human cadaveric knees using a robotic/universal force moment sensor system and an optical tracking system. The knee kinematics under 5- and 10-N·m valgus moments were determined in the different flexion angles of the (1) MCL-intact and (2) MCL-deficient knee using the following simulated muscle loads: (1) 0-N (idle) load, (2) 200-N semitendinosus (ST) load, and (3) 280-N (200/80-N) combined semitendinosus/gracilis (STGT) load.
Results:
Cutting the MCL increased the valgus angle under all tested conditions and angles compared with the MCL-intact knee by 4.3° to 8.1° for the 5-N·m valgus moment and 6.5° to 11.9° for the 10-N·m valgus moment (P < .01). The applied 200-N simulated ST load reduced the valgus angle significantly at 0°, 10°, 20°, and 30° of flexion under 5- and 10-N·m valgus moments (P < .05). At 0°, 10°, and 20° of flexion, these values were close to those for the MCL-intact joint under the respective moments (both P > .05). The combined 280-N simulated STGT load significantly reduced the valgus angle in 0°, 10°, and 20° of flexion under 5- and 10-N·m valgus moments (P < .05) to values near those for the intact joint (5 N·m: 0°, 10°; 10 N·m: 0°, 10°, 20°; P > .05). In 60° and 90° of flexion, ST and STGT loads did not decrease the resulting valgus angle of the MCL-deficient knee without hamstring loads (P > .05 vs deficient; P = .0001 vs intact).
Conclusion:
In this human cadaveric study, semitendinosus and gracilis muscles successfully stabilize valgus moments applied to the MCL-insufficient knee when the knee is near extension.
Clinical Relevance:
In the valgus-unstable knee, these data suggest that the hamstring muscles should be preserved in (multi-) ligament surgery when possible.
Background
The amount of medial compartment opening for medial knee injuries determined by valgus stress radiography has not been well documented. The purpose of this study was to develop clinical ...guidelines for diagnosing medial knee injuries using valgus stress radiography.
Hypothesis
Measurements of medial compartment gapping can accurately differentiate between normal and injured medial structure knees on valgus stress radiographs.
Study Design
Controlled laboratory study.
Methods
Valgus stress radiographs were obtained on 18 adult lower extremities using 10-N·m and clinician-applied valgus loads at 0° and 20° of flexion to intact knees and after sequential sectioning of the superficial medial collateral ligament proximally and distally, the meniscofemoral and meniscotibial portions of the deep medial collateral ligament, the posterior oblique ligament, and the cruciate ligaments. Three independent observers of different experience levels measured all of the radiographs during 2 separate occasions to determine intraobserver repeatability and interobserver reproducibility.
Results
Compared with the intact knee, significant medial joint gapping increases of 1.7 mm and 3.2 mm were produced at 0° and 20° of flexion, respectively, by a clinician-applied load on an isolated grade III superficial medial collateral ligament simulated injury. A complete medial knee injury yielded gapping increases of 6.5 mm and 9.8 mm at 0° and 20°, respectively, for a clinician-applied load. Intraobserver repeatability and interobserver reproducibility intraclass correlation coefficients were .99 and .98, respectively.
Conclusion
Valgus stress radiographs accurately and reliably measure medial compartment gapping but cannot definitively differentiate between meniscofemoral- and meniscotibial-based injuries. A grade III medial collateral ligament injury should be suspected with greater than 3.2 mm of medial compartment gapping compared to the contralateral knee at 20° of flexion, and this injury will also result in gapping in full extension.
Clinical Significance
Valgus stress radiographs provide objective and reproducible measurements of medial compartment gapping, which should prove useful for definitive diagnosis, management, and postoperative follow-up of patients with medial knee injuries.
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.
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