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Management of Medial-Sided Ligamentous Laxity and Posteromedial Corner
Abstract
Medial and posteromedial corner knee injuries are being increasingly recognized as a growing problem in the field of sports medicine. These injuries can cause medial knee pain and side-to-side instability with activity, particularly with participation in sports. Understanding the local anatomy and the native healing properties of the medial aspect of the knee is crucial for the successful treatment of these injuries. Proper diagnosis is best achieved through a combination of physical exam, objective valgus stress radiographs at both 0° and 30° of knee flexion, and magnetic resonance imaging. Management of medial-sided ligament knee injuries includes both conservative and operative treatment, with anatomic reconstruction demonstrating both biomechanical validation and favorable clinical outcomes. Failure to successfully restore medial knee laxity can lead to chronic instability, knee pain, and cruciate ligament failure. Despite the complexity of posteromedial corner injuries, relying on surgically relevant anatomical landmarks is key for successful surgical reconstruction.
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Background:
Medial collateral ligament (MCL) injuries are one of the most commonly treated knee pathologies in sports medicine. The MCL serves as the primary restraint to valgus force. The large majority of these injuries do not require surgical intervention.
Case subject description:
A 30-year-old professional wrestling athlete presented to the clinic with acute complaints of right medial knee pain resulting from a traumatic valgus force. Physical exam revealed Grade 3 MCL injury. Magnetic resonance imaging confirmed clinical diagnosis of a Grade 3 proximal MCL tear. This athlete had sustained a prior grade 3 ACL injury with Grade 3 distal MCL injury which required surgery to reconstruct the ACL and repair the MCL 13 months prior, in November of 2015.
Outcomes:
The subject was successfully treated with a series of three sequential Leukocyte Rich Platelet Rich Plasma (LR-PRP) Injections spaced evenly one week apart in addition to an early physical therapy regimen. The total treatment time was cut down from an expected 35-49 days to 31 days.
Discussion:
When paired with the appropriate rehabilitation treatment progression, the use of LR-PRP injections in the treatment of an isolated MCL tear was beneficial for this subject.
Conclusion:
The results of this case report indicate that the use of LR-PRP and early rehabilitation shows promise in treating an acute grade 3 MCL injury. Future research utilizing randomized controlled trials are needed.
Level of evidence:
Case Report, 4.
Background:
Limited information in basic science and clinical trials exists to determine if ligament healing may be accelerated with the use of biological adjuvants, such as platelet-rich plasma (PRP). However, there has been widespread acceptance of PRP for use in clinical practice, despite an inadequate understanding of its biological mechanism of action.
Purpose:
To determine whether a single dose of PRP could accelerate ligament healing and correspondingly improve histological characteristics and biomechanical properties when injected immediately postoperatively into the injured medial collateral ligament (MCL) of New Zealand White rabbits.
Study design:
Controlled laboratory study.
Methods:
Eighty skeletally mature New Zealand White rabbits (160 knees) were used. The MCL was torn midbody to simulate a grade 3 tear. After an acute injury of the MCL, the administration of autologous PRP at 3 different platelet concentrations (0 million/uL, platelet-poor plasma [PPP]; 0.6 million/uL, 2 times the baseline [2× PRP]; and 1.2 million/uL, 4 times the baseline [4× PRP]) was performed and compared with a saline injection control in the contralateral knee. Histological analysis and a biomechanical endpoint characterization were utilized to assess ligamentous healing and compare it to a sham surgery group.
Results:
The PPP ( P = .001) and 4× PRP ( P = .002) groups had a significantly lower collagen subscore than the sham surgery group. No other differences were observed among the treatment groups, including the vascularity subscore and overall ligament tissue maturity index score. Compared with saline-injected contralateral knees, the maximum load for PPP and 2× PRP was not significantly different ( P = .788 and .325, respectively). The maximum load and stiffness for knees treated with 4× PRP were significantly less than for the saline-treated contralateral knees ( P = .006 and .001, respectively).
Conclusion:
One single dose of PPP or 2× PRP at the time of injury did not improve ligament healing. In addition, 4× PRP negatively affected ligament strength and histological characteristics at 6 weeks after the injury.
Clinical relevance:
The current practice of treating knee ligament injuries with PRP may not improve healing at low doses of PRP. The decreased mechanical properties and histological appearance of the torn MCL suggest that high doses of PRP decrease the quality of repair tissue. Further in vivo studies are necessary to determine the dosing and timing of PRP administration after a ligament injury before the widespread use of PRP to treat ligament injuries is recommended.
Purpose:
To evaluate the use of platelet-rich plasma in the early stages of healing of traumatic injury of the medial collateral ligament in the knee of rabbits.
Methods:
Thirty rabbits were subjected to surgical lesion of the medial collateral ligament. Of these, 16 were treated with platelet-rich plasma and 14 with saline (control). After 3 and 6 weeks of treatment, 50% of the animals from each group were sacrificed, and biomechanical tests were performed on the injured ligament to compare the tensile strength between the two groups.
Results:
Platelet-rich plasma significantly increased the tensile strength of the ligament in the groups treated after3 and 6 weeks. In the group treated with platelet-rich plasma vs. saline, the tensile strength values were 3192.5 ± 189.7 g/f vs. 2851.1 ± 193.1 g/f at3 weeks (p = 0.005) and 5915.6 ± 832.0 g/f vs. 4187.6 ± 512.9 g/f at 6 weeks (p = 0.0001).
Conclusion:
The use of platelet-rich plasma at the injury site accelerated ligament healing in an animal model, demonstrated by an increase in the tensile strength of the medial collateral ligament.
The Orthopaedic Section of the American Physical Therapy Association (APTA) has an ongoing effort to create evidence-based practice guidelines for orthopaedic physical therapy management of patients with musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). The purpose of these revised clinical practice guidelines is to review recent peer-reviewed literature and make recommendations related to knee ligament sprain.
J Orthop Sports Phys Ther. 2017;47(11):A1–A47. doi:10.2519/jospt.2017.0303
The posteromedial corner of the knee encompasses five medial structures posterior to the medial collateral ligament. With modern MRI systems, these structures are readily identified and can be appreciated in the context of multiligamentous knee injuries. It is recognized that anteromedial rotatory instability results from an injury that involves both the medial collateral ligament and the posterior oblique ligament. Like posterolateral corner injuries, untreated or concurrent posteromedial corner injuries resulting in rotatory instability place additional strain on anterior and posterior cruciate ligament reconstructions, which can ultimately contribute to graft failure and poor clinical outcomes. Various options exist for posteromedial corner reconstruction, with early results indicating that anatomic reconstruction can restore valgus stability and improve patient function. A thorough understanding of the anatomy, physical examination findings, and imaging characteristics will aid the physician in the management of these injuries.
Purpose
The purpose of this study was to analyse the clinical outcomes of multiligament injured knees with respect to the medial collateral ligament and posteromedial corner (PMC) repair or reconstruction versus the posterolateral corner (PLC) reconstruction in patients operated according to a codified surgical protocol.
Methods
Patients were divided into two groups depending on whether PMC or PLC was injured. Cruciate ligaments as well as PMC or PLC were reconstructed/repaired in a one-stage procedure. At minimum of 1-year follow-up, objective and subjective International Knee Documentation Committee (IKDC) forms, Lysholm score and sports activity level were recorded.
Results
Thirty-nine patients with a median follow-up time of 57 months (range 12–129) were reviewed. No significant difference was found for functional scores between acute PMC and PLC subgroups. In Group PLC, subjective outcomes tend to be better in the acute than in chronic reconstruction subgroup.
Conclusions
A one-stage protocol with early surgery rather than delayed reconstruction produced better clinical outcomes whatever the injured collateral ligament, medial or lateral. In the future, early and chronic reconstructions as well as each injury pattern should be considered as separate entities in studies on multiple ligament injured knees to reach a better level of evidence.
Level of evidence
IV.
The medial collateral ligament (MCL) and the posterior oblique ligament (POL) are the main static valgus restraints of the knee.
Most isolated medial injuries can be treated with bracing and early knee motion.
Combined MCL and ACL (anterior cruciate ligament) injuries can be managed with bracing of the knee followed by a delayed reconstruction of the ACL.
Residual medial laxity may be addressed at the time of ACL surgery.
Bony avulsions, incarceration of the distal MCL under the meniscus or over the pes anserinus tendons, open injuries, MCL tears combined with PCL or bi-cruciate injuries should be treated surgically.
Chronic symptomatic medial instability can be managed with the recently described reconstruction techniques using free tendon grafts located at anatomical insertion sites.
Cite this article: Tandogan NR, Kayaalp A. Surgical treatment of medial knee ligament injuries: Current indications and techniques. EFORT Open Rev 2016;2:27-33. DOI: 10.1302/2058-5241.1.000007.
The medial collateral ligament (MCL) is the most frequently injured ligament of the knee. Platelet-rich plasma (PRP) is a relatively new treatment option developed to enhance the healing response after injury to different tissue types. This study aimed at investigating whether the addition of PRP to MCL tears in rats would alter healing both biomechanically and histologically.
Bilateral full-thickness tears of the MCL were surgically induced in the knees of 32 rats. Right ligament was saturated with PRP (n = 32, study group), and the left ligament was saturated with saline (n = 32, control group). The animals were killed 3 weeks later and the surgical sites were evaluated by gross inspection, biomechanically and histologically.
There was no gross difference in the mass of granulation tissue, load to failure, stiffness and displacement between the study and control groups. Histological examination by means of maturity score revealed no significant differences between the study and control groups.
The addition of PRP to a healing MCL did not improve any of the outcome measures in this model.
Background
When surgical intervention is required for a grade 3 superficial medial collateral ligament (sMCL) tear, there is no consensus on the optimal surgical treatment. Anatomic augmented repairs and anatomic reconstructions for treatment of grade 3 sMCL tears have not been biomechanically validated or compared.
Hypothesis
Anatomic sMCL augmented repairs and anatomic sMCL reconstruction techniques will reproduce equivalent knee kinematics when compared with the intact state, while creating significant improvements in translational and rotational laxity compared with the sMCL sectioned state.
Study Design
Controlled laboratory study.
Methods
Eighteen match-paired, fresh-frozen cadaveric knees (average age, 52.6 years; range, 40-59 years) were each used to test laxity of an intact sMCL, a deficient sMCL, and either an anatomic augmented repair or an anatomic reconstruction. Knees were biomechanically tested in a 6 degrees of freedom robotic system, which included valgus rotation, internal and external rotation, simulated pivot shift, and coupled anterior drawer with external rotation.
Results
Anatomic augmented repairs and anatomic reconstructions had significantly less medial joint gapping than the sectioned state at all tested flexion angles and showed significant reductions in valgus rotation compared with the sectioned state at all flexion angles. No significant differences between the anatomic augmented repair and anatomic reconstruction were found for any test performed. Despite the similar behavior between the 2 reconstruction groups, neither technique was able to reproduce the intact state.
Conclusion
Anatomic sMCL augmented repairs and anatomic sMCL reconstructions were not significantly different when tested at time zero. Both the anatomic augmented repair and the anatomic reconstruction were able to improve knee stability and provide less than 2 mm of medial joint gapping at 0° and 20° of flexion.
Clinical Significance
These results suggest that both an anatomic sMCL augmented repair and an anatomic sMCL reconstruction improve knee kinematics compared with a deficient sMCL and provide equivalent joint stability.
Platelet-rich plasma (PRP) is derived from centrifuging whole blood to obtain a high platelet concentration containing numerous growth factors. Despite its widespread use, there is still a lack of high-level evidence regarding randomized clinical trials assessing the efficacy of PRP in treating ligament injuries. Although there is research showing an improvement in the early stages of healing in the animal model of acute medial collateral ligament (MCL) injury of the knee, there is no strong evidence to support the efficacy of PRP injections for treating MCL lesions in humans.
In this report, we present a case of an elite football player, treated with multiple PRP local injections followed by rehabilitation, for a high grade MCL lesion of the knee. He was able to resume training at day 18, painfree, with full range of motion and the ability to complete a functional test based on all sport specific movements. He played matches at 25 days with no residual symptoms or functional deficit. There were no further complaints or recurrences at the 16 months follow up.
On the basis of this report, we can assume that the treatment of high grade acute MCL lesions of the knee with PRP is a promising therapeutic option to be further explored with good quality Randomized Controlled Trials (RCTs).
Injuries of the posteromedial corner of the knee are relatively common. These can be isolated or combined with other ligament lesions. In some cases the treatment of postero-medial corner injuries is controversial. After a brief description of the anatomy and biomechanics of the medial side of the knee, this paper reviews the indications for isolated and multiligamentous medial/posteromedial corner injuries both in the acute and in the chronic setting. In addition, the most common surgical techniques for repair and reconstruction are described in addition to outcomes based upon a review of the literature.
Surgeons are often faced with very limited data available to make informed decisions regarding the appropriate treatment of patients with posteromedial corner (PMC) injuries of the knee. This study compared the outcomes of surgical repair versus reconstruction in knee dislocation patients who have sustained injury to the PMC of the knee. Senior author treated 113 consecutive knee dislocations with 115 PMC injuries over 7 years. A total of 71 knee dislocation patients with 73 PMC tears qualified for the study and were followed for a mean of 43 months. Patients who had a PMC repair were assigned to treatment Group A. Group B included patients who had autograft reconstruction of the PMC. Patients who had an allograft PMC were assigned to Group C. A total of 25 patients had a repair, with 5 failures (20%), whereas 48 patients had reconstruction of the PMC with 2 failures (4%). There was a significant difference between the failure rate of PMC repairs and PMC reconstructions. Reconstruction of the PMC using a technique that reestablishes the critical triangle of the medial collateral ligament, the posterior oblique ligament, and the semitendinosus yielded better stability than repair in patients with a knee dislocation that included PMC instability.
Dislocations resulting in multiligament knee injuries are challenging to treat and diagnose. With proper diagnosis and anatomic reconstruction techniques, patients can have successful outcomes. This article describes the senior author's (J.P.S.'s) preferred reconstruction techniques, timing for surgery, and rehabilitation techniques for injuries involving the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), and posteromedial corner (PMC). We prefer to address these injuries in a staged fashion. The PCL, PMC, and any additional meniscal pathology are addressed in the index procedure. The ACL is reconstructed approximately 6 weeks later to ensure that acceptable range of motion has been regained. Staging procedures also allow time to maximize rehabilitation protocols for both the PCL and the ACL.
The patella is the largest sesamoid bone in the body. The patellofemoral joint provides an integral articulating component of the extensor mechanism of the knee joint. A detailed description of patella anatomy, embryology and development, neurovascular anatomy, biomechanical function, and imaging modalities is provided in this article. Common patellar pathologies such as patellar instability, trochlear dysplasia, patella alta and baja, and patellofemoral joint arthritis as well as patellofemoral arthroplasty as a treatment option are also discussed. An understanding of the normal anatomy and biomechanics of the patella is a necessary prerequisite for understanding the pathogenesis of disorders involving the knee.
The structural properties of the individual components of the superficial medial collateral ligament (MCL), deep MCL, and posterior oblique ligament (POL) have not been studied in isolation. To define the necessary strength requirements for an anatomical medial knee reconstruction, knowledge of these structural properties is necessary.
The components of the superficial MCL, POL, and deep MCL have significantly different structural properties.
Controlled laboratory study.
This study used 20 fresh-frozen nonpaired cadaveric knee specimens with a mean age of 54 years (range, 27 to 68 years). These knees provided 8 samples for each tested medial knee structure, which was individually isolated and loaded to failure at 20 mm per minute. Specifically tested were the superficial MCL with intact femoral and detached proximal tibial attachments, the superficial MCL with intact femoral and detached distal tibial attachments, the central arm of the POL, and the isolated deep MCL. Load was recorded as a function of displacement. Stiffness of the ligament at failure was calculated from these measurements.
The mean load at failure for the superficial MCL with the intact femoral and distal tibial attachments was 557 N. Mean load at failure was 88 N for the intact femoral and proximal tibial divisions of the superficial MCL, 256 N for the POL, and 101 N for the deep MCL. Stiffness of the ligaments just before failure was 63, 17, 38, and 27 N/mm, in the same order as above.
The proximal and distal tibial divisions of the superficial MCL, POL, and deep MCL produced loads of clinical importance.
Knowledge of the structural properties of these attachment sites will assist in reconstruction graft choices, fixation method choices, and overall operative treatment of medial knee injury.
Systematic literature review.
To perform a systematic review of randomized controlled trials assessing the effects of neuromuscular electrical stimulation (NMES) on quadriceps strength, functional performance, and self-reported function after anterior cruciate ligament reconstruction.
Conflicting evidence exists regarding the effectiveness of NMES following anterior cruciate ligament reconstruction.
Searches were performed for randomized controlled trials using electronic databases from 1966 through October 2008. Methodological quality was assessed using the Physiotherapy Evidence Database Scale. Between-group effect sizes and 95% confidence intervals (CIs) were calculated.
Eight randomized controlled trials were included. The average Physiotherapy Evidence Database Scale score was 4 out of possible maximum 10. The effect sizes for quadriceps strength measures (isometric or isokinetic torque) from 7 studies ranged from -0.74 to 3.81 at approximately 6 weeks postoperatively; 6 of 11 comparisons were statistically significant, with strength benefits favoring NMES treatment. The effect sizes for functional performance measures from 1 study ranged from 0.07 to 0.64 at 6 weeks postoperatively; none of 3 comparisons were statistically significant, and the effect sizes for self-reported function measures from 1 study were 0.66 and 0.72 at 12 to 16 weeks postoperatively; both comparisons were statistically significant, with benefits favoring NMES treatment.
NMES combined with exercise may be more effective in improving quadriceps strength than exercise alone, whereas its effect on functional performance and patient-oriented outcomes is inconclusive. Inconsistencies were noted in the NMES parameters and application of NMES.
Therapy, level 1a-.
Arthrogenic muscle inhibition is an important underlying factor in persistent quadriceps muscle weakness after knee injury or surgery.
To determine the magnitude and prevalence of volitional quadriceps activation deficits after knee injury.
Web of Science database.
Eligible studies involved human participants and measured quadriceps activation using either twitch interpolation or burst superimposition on patients with knee injuries or surgeries such as anterior cruciate ligament deficiency (ACLd), anterior cruciate ligament reconstruction (ACLr), and anterior knee pain (AKP).
Means, measures of variability, and prevalence of quadriceps activation (QA) failure (<95%) were recorded for experiments involving ACLd (10), ACLr (5), and AKP (3).
A total of 21 data sets from 18 studies were initially identified. Data from 3 studies (1 paper reporting data for both ACLd and ACLr, 1 on AKP, and the postarthroscopy paper) were excluded from the primary analyses because only graphical data were reported. Of the remaining 17 data sets (from 15 studies), weighted mean QA in 352 ACLd patients was 87.3% on the involved side, 89.1% on the uninvolved side, and 91% in control participants. The QA failure prevalence ranged from 0% to 100%. Weighted mean QA in 99 total ACLr patients was 89.2% on the involved side, 84% on the uninvolved side, and 98.5% for the control group, with prevalence ranging from 0% to 71%. Thirty-eight patients with AKP averaged 78.6% on the involved side and 77.7% on the contralateral side. Bilateral QA failure was commonly reported in patients.
Quadriceps activation failure is common in patients with ACLd, ACLr, and AKP and is often observed bilaterally.
An anatomical medial knee reconstruction has not been described in the literature.
Knee stability and ligamentous load distribution would be restored to the native state with an anatomical medial knee reconstruction.
Controlled laboratory study.
Ten nonpaired cadaveric knees were tested in the intact, superficial medial collateral ligament and posterior oblique ligament-sectioned, and anatomically reconstructed states. Each knee was tested at 0 degrees , 20 degrees , 30 degrees , 60 degrees , and 90 degrees of knee flexion with a 10-N.m valgus load, 5-N.m external and internal rotation torques, and 88-N anterior and posterior drawer loads. A 6 degrees of freedom electromagnetic motion tracking system measured angulation and displacement changes of the tibia with respect to the femur. Buckle transducers measured the loads on the intact and reconstructed proximal and distal divisions of the superficial medial collateral ligament and the posterior oblique ligament.
A significant increase was found in valgus angulation and external rotation after sectioning the medial knee structures at all tested knee flexion angles. This was restored after an anatomical medial knee reconstruction. The authors also found a significant increase in internal rotation at 0 degrees , 20 degrees , 30 degrees , and 60 degrees of knee flexion after sectioning the medial knee structures, which was restored after the reconstruction. A significant increase in anterior translation was observed after sectioning the medial knee structures at 20 degrees , 30 degrees , 60 degrees , and 90 degrees of knee flexion. This increase in anterior translation was restored following the reconstruction at 20 degrees and 30 degrees of knee flexion, but was not restored at 60 degrees and 90 degrees . A small, but significant, increase in posterior translation was found after sectioning the medial knee structures at 0 degrees and 30 degrees of knee flexion, but this was not restored after the reconstruction. Overall, there were no clinically important differences in observed load on the ligaments when comparing the intact with the reconstructed states for valgus, external and internal rotation, and anterior and posterior drawer loads. Conclusion An anatomical medial knee reconstruction restores near-normal stability to a knee with a complete superficial medial collateral ligament and posterior oblique ligament injury, while avoiding overconstraint of the reconstructed ligament grafts.
This anatomical medial knee reconstruction technique provides native stability and ligament load distribution in patients with chronic or severe acute medial knee injuries.
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).
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.
Descriptive laboratory study.
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 degrees , 20 degrees , 30 degrees , 60 degrees , and 90 degrees of knee flexion.
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 degrees 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 degrees , 60 degrees , and 90 degrees of knee flexion, and the meniscotibial portion of the deep MCL at 0 degrees and 30 degrees of knee flexion.
An intricate relationship exists among the main medial knee structures and their individual components for static function to applied loads.
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 degrees 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.
The medial collateral ligament is one of the most commonly injured ligaments of the knee. Most injuries result from a valgus force on the knee. The increased participation in football, ice hockey, and skiing has all contributed to the increased frequency of MCL injuries. Prophylactic knee bracing in contact sports may prevent injury; however, performance may suffer. The majority of patients who sustain an MCL injury will achieve their pre-injury activity level with non-operative treatment alone; however, those with combined ligamentous injuries may require acute operative care. Accurate characterization of each aspect of the injury will help to determine the optimum treatment plan.
In cases of multiple ligament injury or severe medial collateral ligament (MCL) lesion, nonoperative treatment of the MCL lesion may lead to chronic valgus instability or rotatory instability.
In a retrospective case series after isolated and combined MCL reconstructions using a novel MCL reconstruction technique that addresses both the MCL and the posteromedial corner, an acceptable clinical outcome is expected 2 years after MCL reconstruction.
Case series; Level of evidence, 4.
From July 2002 to December 2005, 61 patients with grade 3 or 4 medial instability were treated with MCL reconstruction. Median age was 33 years (range, 14-62). Thirteen underwent isolated MCL reconstructions, 34 had combined MCL and anterior cruciate ligament (ACL) reconstruction, and 14 had multiple ligament reconstructions. All patients had reconstruction of the medial collateral and the posteromedial complex using ipsilateral semitendinosus autografts. Fifty patients were available for follow-up more than 24 months postoperatively and were examined by an independent observer using objective International Knee Documentation Committee (IKDC) measures and subjective Knee Injury and Osteoarthritis Outcome Score (KOOS).
At follow-up, medial stability according to the IKDC score showed 98% normal or nearly normal (grade A or B), and for overall IKDC score, patients improved from 5% with grade A or B preoperatively to 74% with grade A or B at follow-up. There were 91% who were satisfied or very satisfied with the result; 88% would go through surgery again. The KOOS improved primarily for sports and quality of life subscales with approximately 10-point improvements.
Acceptable clinical results with the MCL reconstruction technique were achieved in patients suffering from chronic valgus instability.
Background: Meniscal ramp lesions have been defined as a tear of the peripheral attachment of the posterior horn of the medial meniscus (PHMM) at the meniscocapsular junction or an injury to the meniscotibial attachment. Precise anatomic descriptions of these structures are limited in the current literature.
Purpose: To quantitatively and qualitatively describe the PHMM and posteromedial capsule anatomy pertaining to the location of a meniscal ramp lesion with reference to surgically relevant landmarks.
Study Design: Descriptive laboratory study.
Methods: Fourteen male nonpaired fresh-frozen cadavers were used. The locations of the posteromedial meniscocapsular and meniscotibial attachments were identified. Measurements to surgically relevant landmarks were performed with a coordinate measuring system. To further analyze the posteromedial meniscocapsular and meniscotibial attachments, hematoxylin and eosin and alcian blue staining were conducted on a separate sample of 10 nonpaired specimens.
Results: The posterior meniscocapsular attachment had a mean 6 SD length of 20.2 6 6.0 mm and attached posteroinferiorly to the PHMM at a mean depth of 36.4% of the total posterior meniscal height. The posterior meniscotibial ligament attached on the PHMM 16.5 mm posterior and 7.7 mm medial to the center of the posterior medial meniscal root attachment. The meniscotibial ligament tibial attachment was 5.9 6 1.3 mm inferior to the articular cartilage margin of the posterior medial tibial plateau. The posterior meniscocapsular attachment converged with the meniscotibial ligament at the most posterior point of the meniscocap- sular junction in all specimens. Histological staining of the meniscocapsular and meniscotibial ligament PHMM attachments showed similar structure, cell density, and fiber directionality, with no qualitative difference in the makeup of their collagen matri- ces across all specimens.
Conclusion: The anatomy of the area where a medial meniscal ramp tear occurs revealed that the 2 posterior meniscal attach- ments merged at a common attachment on the PHMM. Histological analysis validated a shared attachment point of the menis- cocapsular and meniscotibial attachments of the PHMM.
Clinical Relevance: The findings of this study provide the anatomic foundation for an improved understanding of the menisco- capsular and meniscotibial attachments of the PHMM, which may help provide a more precise definition of a meniscal ramp lesion.
Keywords: knee; ramp lesion; medial meniscus; quantitative anatomy
In dealing with acute knee ligament injuries, the main thing is to find the torn ligaments and to put them together again. Knee reconstruction, on the contrary, is a salvage operation. The questions to be answered are: Who should have a ligament reconstruction? Why should it be done? When should it be done? Where should it be done? Who should do it?
Within the past 20 years, knee ligament injuries have been increasingly reported in the literature to be treated with anatomic reconstructions over soft tissue advancements or sling-type procedures to recreate the native anatomy and restore knee function. Historically, early clinician scientists published on the qualitative anatomy of the knee, which provided a foundation for the initial knee biomechanical studies in the nineteenth and twentieth centuries. Similarly, the work of early sports medicine orthopaedic clinician scientists in the late twentieth century formed the basis for the quantitative anatomic and functional robotic biomechanical studies found currently in the sports medicine orthopaedic literature. The development of an anatomic reconstruction first requires an appreciation of the quantitative anatomy and function of each major stabilizing component of the knee.
This paper provides an overview of the initial qualitative anatomic studies from which the initial knee ligament surgeries were based and expands to recent detailed quantitative studies of the major knee ligaments and the renewed recent focus on anatomic surgical reconstructions.
Anatomic repairs and reconstructions of the anterior cruciate ligament, posterior cruciate ligament, medial collateral ligament and posterolateral corner attempt to restore knee function by rebuilding or restoring the native anatomy. The basis of anatomic reconstruction techniques is a detailed understanding of quantitative knee anatomy. Additionally, an appreciation of the function of each component is necessary to ensure surgical success.
V.
In order to reconstruct the medial knee to restore the original biomechanical function of its ligamentous structures, a thorough understanding of its anatomic placement and relationship with surrounding structures is required. To restore the knee to normal kinematics, the diagnosis and surgical approach have to be aligned, to successfully reconstruct the area of injury. Three important ligaments maintain primary medial knee stability: the superficial medial collateral ligament, posterior oblique ligament, and deep medial collateral ligament. It is important not to exclude the assistance that other ligaments of the medial knee provide, including support of patellar stability by the medial patellofemoral ligament and multiligamentous hamstring tendon attachments. Valgus gapping and medial knee stability is accounted for collectively by every primary medial knee stabilizing structure. The following will review the principal medial knee anatomic and biomechanical properties.
A retrospective study was designed to judge the efficacy of proximal advancement of the medial collateral ligament (MCL) for chronic medial instability of the knee joint. Over a twelve month period, seven patients presented to us with chronic medial knee instability. Four of these had a complete tear of the MCL as an isolated injury and three had an associated cruciate injury, anterior cruciate ligament (ACL) in two patients and posterior cruciate ligament (PCL) in one patient. Patients with a cruciate injury underwent arthroscopic reconstruction using patellar tendon graft and had six months of intensive physiotherapy. The follow up consisted of a questionnaire and physical examination. They were graded on the IKDC and Lysholm knee scoring scales. The average duration of follow up was 31 months. We report good to excellent results on all our patients on the Lysholm scale and in spite of three patients having their knees recorded as abnormal on the IKDC scale, all of them were satisfied, had no pain or residual instability and were back to sporting activities without any external support. While reviewing the literature, we did not come across proximal advancement of the MCL in isolation as performed by us as treatment for chronic medial knee instability though it has been performed previously with a different operative technique or in association with more extensive surgical intervention. Thus, in those few patients who require surgical intervention for this problem, we advocate this technique as a simple and reliable method for treating chronic medial knee instability.
The diagnosis and treatment of combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries have evolved over the past 30 years. A detailed physical examination along with careful review of the magnetic resonance imaging and stress radiographs will guide decision making. Early ACL reconstruction and acute MCL repair are recommended when there is increased medial joint space opening with valgus stress in extension, a significant meniscotibial deep MCL injury (high-riding medial meniscus), or a displaced tibial-sided superficial MCL avulsion (stener lesion of the knee). Delayed ACL reconstruction to allow for MCL healing is advised when increased valgus laxity is present only at 30 degrees of flexion and not at 0 degree. However, at the time of ACL surgery, medial stability has to be re-assessed after the reconstruction is completed. In patients with neutral alignment in the chronic setting, graft reconstruction of both the ACL and MCL is recommended.
Background
Iatrogenic disruption of the patellar vascular supply has been identified as a possible contributing factor to the commonly reported patellofemoral complications following total knee arthroplasty (TKA). We performed an anatomic cadaveric study evaluating the extra-osseous vascular anatomy of the patella, and correlated our findings to routine TKA surgical dissection to determine how to better preserve patellar vascularity.
Methods
and Materials
In twenty-one cadaveric knees arterial cannulas were placed proximally and distally to the patella. A polyurethane compound was then injected producing a visible arterial network. Specimens underwent gross dissection.
Results
In all 21 specimens, the supreme genicular (SGA), medial/lateral superior genicular (MSGA/LSGA), medial/lateral inferior genicular and anterior tibial recurrent arteries communicate forming a peripatellar anastomotic ring supplying the intraosseous patellar system. Both, the SGA (24%) and MSGA (76%) demonstrated dual medial ring contribution. Relating the arterial location to common TKA exposures suggested severe compromise of patellar vascularity.
Conclusion
The medial sided vessels seem to contribute more significantly to the peripatellar anastomotic ring when compared to the lateral sided vessels. Careful soft tissue management has the potential to preserve key vascular structures that could maintain the intraosseous vascular supply to the patella. Understanding the anatomic locations of major arterial systems around the knee joint can potentially help during hemostasis, and can minimize blood lost during TKA.
Clinical Relevance
Recognition of major arterial systems around the knee joint has the potential to minimize iatrogenic disruption of the vascular supply and the complications that can follow (patella devascularization and blood lost).
Background:
Iatrogenic injury to the infrapatellar branch of the saphenous nerve is a common complication of surgical approaches to the anteromedial side of the knee. A detailed description of the relative anatomic course of the nerve is important to define clinical guidelines and minimize iatrogenic damage during anterior knee surgery.
Methods:
In twenty embalmed knees, the infrapatellar branch of the saphenous nerve was dissected. With use of a computer-assisted surgical anatomy mapping tool, safe and risk zones, as well as the location-dependent direction of the nerve, were calculated.
Results:
The location of the infrapatellar branch of the saphenous nerve is highly variable, and no definite safe zone could be identified. The infrapatellar branch runs in neither a purely horizontal nor a vertical course. The course of the branch is location-dependent. Medially, it runs a nearly vertical course; medial to the patellar tendon, it has a -45° distal-lateral course; and on the patella and patellar tendon, it runs a close to horizontal-lateral course. Three low risk zones for iatrogenic nerve injury were identified: one is on the medial side of the knee, at the level of the tibial tuberosity, where a -45° oblique incision is least prone to damage the nerves, and two zones are located medial to the patellar apex (cranial and caudal), where close to horizontal incisions are least prone to damage the nerves.
Conclusions:
The infrapatellar branch of the saphenous nerve is at risk for iatrogenic damage in anteromedial knee surgery, especially when longitudinal incisions are made. There are three low risk zones for a safer anterior approach to the knee. The direction of the infrapatellar branch of the saphenous nerve is location-dependent. To minimize iatrogenic damage to the nerve, the direction of incisions should be parallel to the direction of the nerve when technically possible.
Clinical relevance:
These findings suggest that iatrogenic damage of the infrapatellar branch of the saphenous nerve can be minimized in anteromedial knee surgery when both the location and the location-dependent direction of the nerve are considered when making the skin incision.
In a prospective randomized study, 20 patients with isolated grade-III injuries to the medial collateral ligament (MCL) of the knee were treated by two different conservative methods: immediate mobilization (group A) or plaster immobilization (group B). All patients were examined while under anesthesia. Valgus-stress radiographs were performed to document a 2+ opening (6–10mm) on the medial side. Associcated damage to other structures (cruciate ligaments, menisci, cartilage) was ruled out arthroscopically. Average follow-up was 1.5 years. All patients rated good or excellent, although a minimal laxity of 3 mm on valgus-stress radiographs was present in 60% of the cases. No significant differences between the two treatment modalities were identified, except that group-A patients returned to work sooner. These results confirm that isolated grade-III MCL tears can be treated successfully by immediate mobilization.
We present a novel and simple method for single hamstring allograft MCL and PMC reconstruction, which can improve both joint valgus and external rotational stability and maximize utilization of allograft. All patients received arthroscopic evaluation through inferomedial and inferolateral knee incisions to ascertain whether there were intra-articular injuries. An 8-cm-length longitudinal incision was made from 1 cm above adductor tubercle to 5-cm proximal medial tibia joint line. The anterior tibia insertion was defined as 15 mm lateral from the medial tibia edge and 45 mm below the medial tibia joint line. The posterior tibia insertion was defined as 15 mm lateral from the medial tibia edge and 20 mm below the medial tibia joint line. A 5- or 6-mm reamer was used to drill the tibia tunnel along with guide pin, and a 6 or 7 mm drill was used to drill the femur tunnel to a depth of 25 or 30 mm until the proximal adductor tubercle. The allograft was harvested from tibia and placed into the tunnel and fixed with absorbable interference screw. All patients performed active rehabilitation exercises after the operation periodically.
Background:
Symptomatic medial collateral ligament (MCL) instability is rare, and it is frequently associated with multiligament injuries. Most clinical investigations have failed to clearly define the specific objective outcome measures assessing the stability of the MCL quantitatively before and after the reconstruction procedure.
Purpose:
To quantitatively evaluate the early clinical outcomes of patients with valgus instability of knee joints who had undergone superficial MCL reconstruction using Achilles tendon allografts.
Study design:
Case series; Level of evidence, 4.
Methods:
From August 2005 to December 2010, 19 consecutive patients with MCL injuries were included in this study. The inclusion criteria were (1) a subacute or chronic MCL injury, with a time from initial injury to surgery of longer than 3 weeks, and (2) valgus laxity graded C or D according to the International Knee Documentation Committee (IKDC). All patients underwent superficial MCL reconstruction using Achilles tendon allografts. To evaluate the laxity of the MCL preoperatively and postoperatively, valgus stress radiographs using a Telos device were used. Other assessments included the IKDC subjective functional evaluation and Lysholm score estimation.
Results:
Sixteen of the 19 patients (12 men and 4 women) were available for final follow-up. The median age of the patients was 37 years (range, 19-53 years); mean body mass index (BMI) was 26.4 (range, 21.7-29.4). The mean time from injury to surgery was 15.9 months (range, 24 days to 84 months), and median follow-up period was 34 months (range, 24-67 months). The mean medial knee laxity (side-to-side difference) was 8.9 ± 3.2 mm (range, 6-15.9 mm) preoperatively and 1.1 ± 0.9 mm (range, -1.1 to 3.2 mm) postoperatively (P < .001). The preoperative mean IKDC subjective knee functional score was 49.8 ± 6.9 (range, 31-57.5), while the postoperative functional score was 84.3 ± 6.0 (range, 71.3-93.1) (P < .001). The mean Lysholm score was 69.3 ± 5.9 (range, 55-78) preoperatively and 88.6 ± 5.0 (range, 75-95) postoperatively (P < .001). There was no significant correlation between patients' BMI and the final clinical outcome scores (P = .311).
Conclusion:
In a small set of patients with multiligament-injured knees, valgus laxity can be effectively restored through surgical management with superficial MCL reconstruction, when the other associated ligament injuries are reconstructed as well. The subjective functional results were significantly improved postoperatively at short-term follow-up.
Purpose:
The case of a patient with knee valgus and instability due to combined ACL-MCL laxity who underwent lateral opening wedge distal femoral osteotomy (DFO) is presented. The symptoms of instability resolved following the surgery. It was unclear whether the increase in valgus stability was related only to a decrease in valgus moments during stance or also to a medial tensioning effect. We therefore performed a laboratory cadaveric study. The purpose of this study was to examine whether after MCL and ACL sectioning, lateral opening wedge DFO would result in decrease in medial opening under static conditions of valgus stress.
Methods:
Medial knee opening under valgus load of 9.8 Nm was tested in 8 cadaveric specimens in scenarios of MCL and ACL sectioning and compared before and after performing lateral opening wedge DFO.
Results:
When the superficial MCL was sectioned, medial knee opening in 30° flexion decreased after lateral opening wedge DFO compared to medial opening before the osteotomy (i.e. from 6.5 ± 0.5° to 5.6 ± 0.5°, p = 0.01). When the superficial MCL, deep MCL, and ACL were all sectioned, medial knee opening in extension decreased after lateral opening wedge DFO compared to medial opening before the osteotomy but this was not significant (i.e. from 6.8 ± 0.5° to 6.1 ± 0.5°, p = n.s.).
Conclusion:
In superficial MCL-transected knees, medial laxity at 30° of knee flexion decreased after lateral opening wedge DFO. However, the clinical relevance of the laxity decrease observed remains uncertain since the reduction was small in magnitude.
The purpose of this study was to present a novel medial collateral ligament (MCL) reconstruction technique and investigate the clinical outcomes of this surgical procedure.
From July 2006 to June 2009, 56 patients with medial instability of the knee were treated with MCL reconstruction and followed up for 33 months on average. These patients were divided into 2 groups based on whether anterior cruciate ligament (ACL) injury was present: 27 patients had isolated MCL injury, whereas 29 patients had combined MCL-ACL injury. All patients underwent reconstruction of the MCL with triangular double-bundle allograft, and we evaluated International Knee Documentation Committee (IKDC) scores, anteromedial rotatory instability (AMRI), and excessive knee medial opening (EKMO) both preoperatively and at follow-up.
EKMO was significantly reduced to 2.9 mm at follow-up compared with 10.1 mm preoperatively. The incidence of AMRI was reduced to 9.4% (5 patients) compared with 67.9% (36 patients) preoperatively. Of the patients, 58.9% (33 patients) had a grade A IKDC subjective score and 35.7% (20 patients) had a grade B IKDC subjective score. Most patients had normal or nearly normal range of motion of the knee joint, whereas 4 patients (7.1%) lost more than 6° of range of motion in extension and 2 (3.6%) lost more than 25° in flexion. In 47 patients (83.9%) the symptoms were graded as normal or nearly normal according to IKDC symptom scores. No significant differences in IKDC subjective score, IKDC symptom score, flexion deficit score, AMRI, and EKMO were found between the isolated MCL injury group and the MCL-ACL injury group; however, a significant difference was found in knee extension deficit between groups.
We have presented a new technique for reconstruction of the MCL with a triangular shape. This technique improved both valgus and rotational stability at short-term outcome. The clinical outcomes using IKDC evaluation indicate that no major difference exists in isolated MCL injury and combined MCL-ACL injury treated with this new technique.
Level IV, therapeutic case series.
Posterior cruciate ligament (PCL) injuries are often associated with injuries of the posteromedial structures of the knee. The motivation for this study was the attempt to test different reconstruction techniques for the structures of the posteromedial corner in a biomechanical experiment.
Kinematic studies were carried out on 10 cadaveric knees exposed to a 134-N posterior tibial load, 10-Nm valgus torque, and 5-Nm internal torque at 0°, 30°, 60°, and 90° of flexion. The resulting posterior tibial translation (PTT) was determined using a robotic/universal force-moment sensor testing system for (1) intact knees, (2) PCL-deficient knees, (3) knees with deficiency of the PCL and the posteromedial structures, (4) knees with only the PCL reconstructed, (5) knees with the PCL and posterior oblique ligament (POL) reconstructed, and (6) knees with the PCL, medial collateral ligament (MCL), and POL reconstructed. Kinematic data were analyzed by a 2-factor repeated analysis of variance.
When both the PCL and the posteromedial structures were cut, PTT increased significantly at all flexion grades under a posterior tibial load (P < .05). Reconstruction of only the PCL could not restore PTT at 0°, 30°, 60°, and 90° of flexion under loading conditions in a knee with combined injury of the PCL and the posteromedial structures (P > .05). Additional reconstruction of the POL improved PTT at all flexion angles in comparison with only the PCL-reconstructed knee. Reconstruction of the MCL had no significant effect on PTT.
This study shows that reconstruction of the POL contributes significantly to the normalization of coupled PTT in knees with combined injury of the PCL and the posteromedial structures under valgus or internal rotational moment. The supplementary reconstruction of the MCL did not provide significant improvement in knee kinematics.
The POL should be addressed in the patient with combined injuries of the PCL and the posteromedial structures.
Purpose
Platelet-rich plasma (PRP) has been increasingly used in sports-related injuries for therapeutic applications. However, there are numerous manufacturing procedures and treatment protocols of PRP use, which make difficult to assess its real efficacy for tissue healing. This study addressed to evaluate the therapeutic effects of locally delivered plasma rich in growth factors (PRGF-Endoret) on the early healing of medial collateral ligament (MCL) in rabbit knees.
Methods
Thirty-one Japanese white rabbits were subjected to a mop-end tear in the MCL of the left knee. PRGF-Endoret was prepared using Anitua’s technique. Two groups were set up. In 17 knees, prepared 1.0 ml of PRGF-Endoret after clotting was applied on the tear site, while in 14 knees the tear site was untreated serving as a control. Quantitative aspects of PRGF-Endoret, the concentration of platelets, leukocytes and erythrocytes and therapeutic growth factors such as PDGF-BB and TGF-β1 were measured. Rabbits were sacrificed at 3 and 6 weeks after the operation and histological and biomechanical evaluation were performed.
Results
No leukocytes were measured and certain amount of growth factors such as PDGF-BB and TGF-β1 were confirmed in the PRGF-Endoret. PRGF-Endoret stimulated proliferation of fibroblasts and neovascularization, and induced statistically better structural properties in repaired MCL.
Conclusions
Our findings provide evidence that local administration of PRGF-Endoret promotes early steps in ligament healing and the repair of structural properties in a rabbit model. PRGF-Endoret would be a useful product in clinical treatment of ligament injuries.
This article describes a treatment approach to knee dislocation based on the healing potentials of individual ligament structures. The posterior cruciate liagament can heal, and posterior laxity of 2+ or less may not need surgical treatment. The medial collateral ligament can heal and does not need surgical treatment. Acute surgery is required only for the lateral side structures. The authors briefly describe a treatment approach that takes advantage of the body's attempt to heal, by reattaching the lateral structures en masse to the lateral capsule attachment site, instead of dissecting each lateral structure.
Injuries to the medial side of the knee are the most common knee ligament injuries. The majority of injuries occur in young athletes during sporting events, with the usual mechanism involving a valgus contact, tibial external rotation, or a combined valgus and external rotation force delivered to the knee. Although most complete grade III medial knee injuries heal, some do not, which can lead to continued instability. For these patients, a thorough understanding of the presenting history and a physical examination are important because these injuries can often be confused with posterolateral corner injuries. The main anatomic structures of the medial side of the knee are the superficial medial collateral ligament, deep medial collateral ligament, and posterior oblique ligament. In addition, accurately locating 3 bony prominences over the medial aspect of the knee-the adductor tubercle, gastrocnemius tubercle, and medial epicondyle-is important to conduct a proper physical examination and for surgical repairs and reconstructions. Clinical diagnosis of medial knee injuries is primarily performed via the application of a valgus stress in full extension and at 30° of knee flexion. In addition, an examination of the amount of anteromedial tibial rotation is performed at 90° of flexion, while the dial test, performed at 30° and 90° of flexion, is important because it evaluates for rotational abnormalities. Valgus stress radiographs are useful to objectively determine the amount of medial compartment gapping and to discern whether there is medial or lateral compartment gapping when a medial or posterolateral corner knee injury cannot be differentiated, especially with a chronic injury. The majority of acute grade III medial knee injuries will heal after a nonoperative rehabilitation program. In most instances when there is a knee dislocation or multiligament injury, a primary repair with sutures may be indicated. In severe midsubstance injuries or chronic medial knee injuries, an anatomic medial knee reconstruction with grafts may be indicated. Rehabilitation principles for acute medial knee injuries involve controlling edema, regaining range of motion, and avoiding any significant stress on the healing ligaments. A well-guided rehabilitation program can result in excellent functional outcomes in the majority of patients.
To develop an evidence-based algorithm for the treatment of combined complete tears of the anterior cruciate ligament (ACL) and medial collateral ligament (MCL).
We performed a systematic review using computerized keyword searches of Medline, Embase, CINAHL (Cumulative Index to Nursing and Allied Health Literature), ACP Journal Club, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews. Two reviewers independently performed searches and article reduction. Studies that reported stratified outcomes data after the treatment of combined complete tears of the ACL and MCL were included. Data on clinical measures of laxity, range of motion, and strength, as well as subjective outcome measures, were summarized.
Five different treatment approaches were reported. Outcomes were better if the ACL was reconstructed and reconstruction was delayed to allow a return of knee range of motion. In many cases, this delay may allow the MCL to heal. MCL repair or reconstruction may be required if valgus instability remains after an appropriate rehabilitation period.
ACL reconstruction should be performed in a subacute time frame once full motion has returned. Valgus instability should be assessed at that time and MCL repair or reconstruction performed in those patients with persistent valgus instability.
Level IV, systematic review of Level I to IV studies.
The orthopaedic literature contains relatively little quantitative information regarding the anatomy of the posterior aspect of the knee. The purpose of the present study was to provide a detailed description of, and to propose a standard nomenclature for, the anatomy of the posterior aspect of the knee.
Detailed dissection of twenty nonpaired, fresh-frozen knees was performed. Posterior knee structures were measured according to length, width, and/or distance to reproducible osseous landmarks.
The semimembranosus tendon had eight attachments distal to the main common tendon. The main components were a lateral expansion to the oblique popliteal ligament; a direct arm, which attached to the tibia; and an anterior arm. The oblique popliteal ligament, the largest posterior knee structure, formed a broad fascial sheath over the posterior aspect of the knee and measured 48.0 mm in length and 9.5 mm wide at its medial origin and 16.4 mm wide at its lateral attachment. It had two lateral attachments, one to the meniscofemoral portion of the posterolateral joint capsule and one to the tibia, along the lateral border of the posterior cruciate ligament facet. The semimembranosus also had a distal tibial expansion, which formed a posterior fascial layer over the popliteus muscle. A thickening of the posterior joint capsule, the proximal popliteus capsular expansion, which in this study averaged 40.5 mm in length, connected the posteromedial knee capsule at its attachment at the intercondylar notch to the medial border of the popliteus musculotendinous junction. The plantaris muscle, popliteofibular ligament, fabellofibular ligament, and semimembranosus bursa were present in all specimens.
The anatomy of the posterior aspect of the knee is quite complex. This study provides information that can lead to further biomechanical, radiographic imaging, and clinical studies of the importance of these posterior knee structures.
Although various surgical procedures have attempted to restore valgus stability in medial knee injuries, so far none has achieved satisfactory results. The purpose of this study was to assess clinical outcome for patients with grade 3 valgus instability who were treated according to our surgical management strategy.
Eighteen patients with both acute and chronic grade 3 medial knee injuries, all of which had combined cruciate ligament injuries, were treated with a proximal advancement of both the superficial medial collateral ligament (MCL) and posterior oblique ligament together with underlying deep MCL and joint capsule, in conjunction with cruciate ligament reconstructions in chronic phase. Augmentation with doubled semitendinosus tendon was added in 7 patients whose medial knee stability had been considered to be insufficient with only the proximal advancement procedure. They were evaluated preoperatively and at final follow-up.
Manual valgus laxities at 0° and 30°, as well as side-to-side difference in medial joint opening in stress radiograph, were significantly improved at final follow-up. The Lysholm knee scale was also significantly improved. Median values of the subjective evaluations of the patients' satisfaction, stability and sports performance level measured with visual analogue scale at final follow-up were 82 (60-100), 94 (71-100) and 88 (60-100), respectively.
Clinical outcomes of our surgical management strategy were reasonable in terms of restoring medial knee stability. This treatment protocol can help determine the surgical management of grade 3 medial knee injuries combined with cruciate ligament injuries.
Retrospective case series, Level IV.
Current fixation techniques in medial knee reconstructions predominantly utilize interference screws alone for soft tissue graft fixation. The use of concurrent fixation techniques as part of a hybrid fixation technique has also been suggested to strengthen soft tissue fixation, although these hybrid fixation techniques have not been biomechanically validated. The purpose was to biomechanically evaluate two distal tibial superficial MCL graft fixation techniques that consisted of an interference screw alone and in combination with a cortical button. Furthermore, the aim was to compare interference screws of different constructs. Twenty-four porcine tibias (average bone mineral density of 1.3 ± 0.2 g/cm(2); range, 1.0-1.6 g/cm(2), measured by DEXA scan) were divided into 4 groups of six specimens each. Group Ia consisted of a 7 × 23-mm poly-L-lactide (PLLA) interference screw. Group Ib utilized a PLLA interference screw in combination with a cortical button. Group IIa consisted of a 7 × 23-mm composite 70% poly(L-lactide-co-D, L-lactide) and 30% biphasic calcium phosphate (BCP) interference screw. Group IIb also utilized a composite interference screw in combination with a cortical button. The specimens were biomechanically tested with cyclic (500 cycles, 50-250 N, 1 Hz) and load-to-failure (20 mm/min) parameters. During cyclic loading, a significant increase in stiffness was seen for the PLLA hybrid 29.6 (±6.9) N/mm fixation compared to the PLLA screw-only 21.2 (±3.8) N/mm group (P < 0.05). Failure loads were 407.8 (±77.9) N for the composite screw, 445 (±72.2) N for the PLLA screw-only, 473.9 (±69.6) N for the composite hybrid fixation, and 511.0 (±78.5) N for the PLLA hybrid fixation. The PLLA screw alone was found to provide adequate fixation for a superficial MCL reconstruction, and the use of a cortical suture button combined with the PLLA screw resulted in a stiffer fixation during cyclic loading. The current reconstruction superficial MCL graft fixation technique utilizing a PLLA interference screw alone serves as an adequate recreation of the native tibial superficial MCL strength. In addition, a hybrid fixation with a cortical button which lends additional cyclic stiffness to its fixation would be advisable for use in suboptimal fixation cases.
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.
Measurements of medial compartment gapping can accurately differentiate between normal and injured medial structure knees on valgus stress radiographs.
Controlled laboratory study.
Valgus stress radiographs were obtained on 18 adult lower extremities using 10-N.m and clinician-applied valgus loads at 0 degrees and 20 degrees 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.
Compared with the intact knee, significant medial joint gapping increases of 1.7 mm and 3.2 mm were produced at 0 degrees and 20 degrees 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 degrees and 20 degrees , respectively, for a clinician-applied load. Intraobserver repeatability and interobserver reproducibility intraclass correlation coefficients were .99 and .98, respectively.
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 degrees 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.
The purpose of this study was to develop a method of femoral fixation for complex revision anterior cruciate ligament (ACL) reconstructions that would avoid a staged bone grafting approach. We evaluated the use of a calcium phosphate cement as a structural bone void filler that would allow for a single-stage revision ACL reconstruction with initial biomechanical properties equivalent to standard autologous bone-patellar tendon-bone primary ACL reconstruction.
We tested 11 matched pairs of fresh-frozen cadaveric knees (N = 22). Controls were treated with autologous bone-patellar tendon-bone primary ACL reconstruction fixed with bioabsorbable interference screws with a 1-mm back wall. The contralateral knee of each pair had a large bone void created that would hamper subsequent femoral fixation to simulate revision ACL reconstruction conditions. This defect was filled with calcium phosphate cement arthroscopically. After solidification, the femoral tunnel was drilled through the bone void filler and native bone with a 1-mm back wall, allowing anatomic positioning. The autologous graft was then placed and fixed with a bioabsorbable interference screw. Specimens were then tested in an MTS machine (MTS Systems, Eden Prairie, MN) for load to failure according to a standard protocol and compared with matched controls.
Failure loads for the control group averaged 312 N (standard deviation [SD], 127 N) and were not significantly different compared with the calcium phosphate cement revision group, which averaged 301 N (SD, 95 N) (P = .80). Failure occurred at the femoral bone block in both groups but without screw pullout.
Statistical analysis failed to show a significant difference between the control group and the group undergoing structural bone void filler revision in this biomechanical evaluation of initial fixation strength.
This technique may allow surgeons to perform a single-stage revision ACL reconstruction in the presence of a contained bone void and avoid the need for a staged procedure if clinical studies verify long-term incorporation of the bone void filler.
Radiographic landmarks for medial knee attachment sites during anatomic repairs or reconstructions are unknown. If identified, they could assist in the preoperative evaluation of structure location and allow for postoperative assessment of reconstruction tunnel placement.
Radiopaque markers were implanted into the femoral and tibial attachments of the superficial medial collateral ligament and the femoral attachments of the posterior oblique and medial patellofemoral ligaments of eleven fresh-frozen, nonpaired cadaveric knee specimens. Both anteroposterior and lateral radiographs were made. Structures were assessed within quadrants formed by the intersection of reference lines projected on the lateral radiographs. Quantitative measurements were performed by three independent examiners. Intraobserver reproducibility and interobserver reliability were determined with use of intraclass correlation coefficients.
The overall intraclass correlation coefficients for intraobserver reproducibility and interobserver reliability were 0.996 and 0.994, respectively. On the anteroposterior radiographs, the attachment sites of the superficial medial collateral ligament, posterior oblique ligament, and medial patellofemoral ligament were 30.5 +/- 2.4 mm, 34.8 +/- 2.7 mm, and 42.3 +/- 2.1 mm from the femoral joint line, respectively. On the lateral femoral radiographs, the attachment of the superficial medial collateral ligament was 6.0 +/- 0.8 mm from the medial epicondyle and was located in the anterodistal quadrant. The attachment of the posterior oblique ligament was 7.7 +/- 1.9 mm from the gastrocnemius tubercle and was located in the posterodistal quadrant. The attachment of the medial patellofemoral ligament was 8.9 +/- 2.0 mm from the adductor tubercle and was located in the anteroproximal quadrant. On the lateral tibial radiographs, the proximal and distal tibial attachments of the superficial medial collateral ligament were 15.9 +/- 5.2 and 66.1 +/- 3.6 mm distal to the tibial inclination, respectively.
The attachment locations of the main medial knee structures can be qualitatively and quantitatively correlated to osseous landmarks and projected radiographic lines, with close agreement among examiners.
Numerous studies have documented the effect of complete medial collateral ligament injury on anterior cruciate ligament loads; few have addressed how partial medial collateral ligament disruption affects knee kinematics.
To determine knee kinematics and subsequent change in anterior cruciate ligament load in a partial and complete medial collateral ligament injury model.
Controlled laboratory study.
Ten human cadaveric knees were sequentially tested by a robot with the medial collateral ligament intact, in a partial injury model, and in a complete injury model with a universal force-moment sensor measuring system. Tibial translation, rotation, and anterior cruciate ligament load were measured under 3 conditions: anterior load (125 N), valgus load (10 N x m), and internal-external rotation torque (4 N x m; all at 0 degrees and 30 degrees of flexion).
Anterior and posterior translation did not statistically increase with a partial or complete medial collateral ligament injury at 0 degrees and 30 degrees of flexion. In response to a 125 N anterior load, at 0 degrees , the anterior cruciate ligament load increased 8.7% (from 99.5 to 108.2 N; P = .006) in the partial injury and 18.3% (117.7 N; P < .001) in the complete injury; at 30 degrees , anterior cruciate ligament load was increased 12.3% (from 101.7 to 114.2 N; P = .001) in the partial injury and 20.6% (122.7 N; P < .001) in the complete injury. In response to valgus torque (10 N x m) at 30 degrees , anterior cruciate ligament load was increased 55.3% (30.4 to 47.2 N; P = .044) in the partial injury model and 185% (86.8 N; P = .001) in the complete injury model. In response to internal rotation torque (4 N.m) at 30 degrees , anterior cruciate ligament load was increased 29.3% (27.6 to 35.7 N; P = .001) in the partial injury model and 65.2% (45.6 N; P < .001) in the complete injury model. The amount of internal rotation at 30 degrees of flexion was significantly increased in the complete injury model (22.8 degrees ) versus the intact state (19.5 degrees ; P < .001).
Partial and complete medial collateral ligament tears significantly increased the load on the anterior cruciate ligament. In a partial tear, the resultant load on the anterior cruciate ligament was increased at 30 degrees of flexion and with valgus load and internal rotation torque.
Patients may need to be protected from valgus and internal rotation forces after anterior cruciate ligament reconstruction in the setting of a concomitant partial medial collateral ligament tear. This information may help clinicians understand the importance of partial injuries of the medial collateral ligament with a combined anterior cruciate ligament injury complex.