RESEARCH ON THE ANATOMY AND RESULTS OF RECONTRUCTION TREATMENT TO THE POSTERIOR CRUCIATE LIGAMENT AND THE COMPLEX POSTEROLATERAL CORNER OF THE KNEE JOINT

Military Medical UniversityTRAN DUC TAI RESEARCH ON THE ANATOMY AND RESULTS OF RECONTRUCTION TREATMENT TO THE POSTERIOR CRUCIATE LIGAMENT AND THE COMPLEX POSTEROLATERAL CORNER OF THE KNE

Military Medical University

TRAN DUC TAI

RESEARCH ON THE ANATOMY AND RESULTS OF RECONTRUCTION TREATMENT TO THE POSTERIOR CRUCIATE LIGAMENT AND THE COMPLEX POSTEROLATERAL CORNER OF THE

KNEE JOINT.

Speciality: SurgeryCode: 9720104

SUMMARY OF DOCTOR OF PHYSOLOPHY THESIS

HA NOI – 2025

Full name of supervisor:

1 Assoc Prof PhD Le Quang Tri

2 Assoc Prof PhD Dang Hoang Anh

Debater 1: Assoc Prof PhD Nguyen Manh Khanh

Debater 2: Assoc Prof PhD Nguyen Van Luong

Debater 3: Prof PhD Nguyen Duy Bac

The thesis will be defended before the school-level thesis examining council at: day month year

The thesis can be found at:

1 National Library

2 Military Medical Academy Library

PROBLEM STATEMENT

The posterolateral corner (PLC) has the primary role of stabilizingthe knee joint to prevent the lower leg from becoming internally andexternally rotated, and the secondary role is to keep the tibial plateaufrom sliding posteriorly The three main structures of the PLC are thelateral collateral ligament (LCL), the popliteal tendon (PT), and the

popliteofibular ligament (PFL)

PLC injuries often occur with injuries to other structures of theknee joint, especially injuries to the PCL and anterior cruciateligament (ACL) Up to 70% of PCL injuries are thought to occursimultaneously with PLC When both PCL and PLC are damaged atthe same time, the patient always feels that the knee joint is unstablewhen rotating externally, or changes direction of external rotationwhen moving, causing difficulty in daily activities According toauthor DeLee J C (1983), the rate of simple PLC injury is 1.6% andPLC injury with PCL rupture is 4.4% Laprade R (2006) estimated therate of PLC injuries to be 5 - 9% of all knee joint injuries

Diagnosis of PLC injury is based on the history of injury, clinicaltests (external recurvatum test, varus test, dial test ) and imaging(Varus gap on stress radiography and MRI ) Treatment ofPLC and PCL includes conservative and surgical treatments.Surgical techniques to restore PLC, some authors advocatereconstruction of LCL, PT and PFL (the Laprade R technique).Some authors advocate only reconstructing LCL and PT withoutreconstructing PFL (the Larson technique) Currently, manysurgeons combine single-bundle PCL reconstruction and PLC

reconstruction according to the Larson technique to treat patientswith chronic PLC injury.

In order for surgery to reconstruct the PCL and PLC with goodresults, it is necessary to clearly understand the anatomy of eachligament such as attachment location, attachment area, path, and size

of the ligaments and the relationship between ligaments Manyauthors around the world have delved into research on the anatomicalcharacteristics of the PLC, especially the location of attachmentareas such as the studies of Terry G C., Laprade R., Sugita T InVietnam, Do Van Minh described the anatomical characteristics ofsimple PCL, thereby applying it in laparoscopic surgery toreconstruct PCL Le Hoang Truc Phuong described the anatomicalcharacteristics of PLC for the application of PLC knee jointreconstruction surgery However, there have been no studies thatsimultaneously describe the anatomical characteristics of PCL andPLC, thereby applying it in simultaneous reconstructive surgery ofthis complex Therefore, we carry out this topic with two goals:

1 Describe some anatomical characteristics of the PCL, the

LCL, PT, and PFL on cadavers of Vietnamese adults.

2 Evaluate the results of treating injuries of the posterior cruciate ligament and posterolateral corner of the knee joint.

URGENCY OF THE TOPIC:

Previously, complex injuries of PLC and PCL were oftenoverlooked and did not fully restore knee stability when simplyreconstructing the PCL The simultaneous reconstruction technique ofPLC and PCL is a new technique that has been implemented at several

major specialized centers in Vietnam in the past few years Therefore,the topic is topical, and urgent, and provides a new, morecomprehensive perspective on the treatment of knee injuries.

SUMMARY OF NEW MAIN SCINETIFIC CONTRIBUTION

OF THE THESIS

The research results have provided anatomicalcharacteristics and accuracy diagnosis of the PCL andcomponents of the posterolateral corner, helpingsurgeons comprehensively examine injuries of the kneejoint and developing a pre-operative plan

Positive surgical results provide a new surgicaltreatment technique for patients with lesions like thePCL and PCL of the knee The thesis contributes toteaching research and is a useful reference in the field

of orthopedics and surgery

THESIS STRUCTURE:

The thesis consists of 133 pages The thesis include theintroduction (02 pages), conclusion (02 pages), and consists of 4chapters: Overview 32 pages; Research Objects and Methods 31pages; Results 34 pages; Discussion 32 pages; including 56 tables, 7charts, and 53 images

Chapter 1 LITERATURE REVIEW 1.1 Anatomy and biomechanics of the PLC and PCL

PLC of the knee joint is the structure located on the posteriorlydisplaced outside of the knee joint The PLC anatomy can be dividedinto layers from the outside to the inside (superficial, middle, deep).The three main components of PLC are the LCL, PT, and PFL

1.1.2 Middle layer

Corresponding to the deep layer of the iliotibial band, lining themedial aspect of the superficial layer of the iliotibial band, attaches tothe lateral aspect of the femoral intermuscular fascia Lateral and distal

to the femoral condyle, the two superficial and deep layers will mergeand attach to the Gerdy's tubercle

1.1.3 Deep layer

Contains the main components of the PLC, which is subdividedinto a superficial compartment and a deep compartment The LCL andthe peroneal sesamoid ligament are located on the lateral side of thesuperficial layer, and the arcuate ligament extends across the posterioraspect of the lateral femoral condyle The deepest layer contains the

PT The PFL runs from the PT to the styloid process of the fibula

1.1.3.1 Lateral collateral ligament (LCL)

Plays a major role in limiting the internal curvature of the kneejoint The LCL attaches to the lateral femoral condyle and fibular head,with a length of about 6,3-7,1cm Research shows that when the knee

is flexed at 30°, the LCL bears the greatest force in limiting the internalcurvature, and this force decreases when the knee is flexed at 90° TheLCL also bears the highest tension when the knee is flexed at 0°, andthe least at 90°

1.1.3.2 Popliteus tendon (PT)

PT is located posterior to the medial tibial plateau and has amuscle belly that attaches to the hamstring tendon groove behind thelateral femoral condyle At the hamstring tendon (HT) pit, the musclegradually shifts to the tendon bar and the tendon lies on HT groove.The PT part will enter the joint and go deeper than LCL, then attach

to the femur at a distance of 9,7mm from the highest point of thecondyle, 5,5mm behind

1.1.3.3 Popliteofibular ligament (PFL)

The PFL originates from the HT superior to the muscle boundary of the popliteus muscle and connects HT to thestyloid process at the superior end of the fibula PFL plays animportant role in limiting external rotation of the tibia, especially atdifferent flexion angles

tendon-1.1.4 Posterior cruciate ligament (PCL)

PCL has an average length of 32-38mm, cross-sectional area

in the middle is about 31.2 mm2, about 1,5 times wider than ACL Thefemoral attachment area extends more than 20mm in the anterior-posterior direction, from the roof of the femoral condyle to the inner

surface of the intercondylar area The main grip is located from 9o'clock to 12 o'clock clockwise (left knee) or from 3 o'clock to 12o'clock counterclockwise (right knee) The tibial attachment area islocated on the surface of the tibial plateau, between the two posteriorhorns of the menicus, extending further below the posterior border ofthe tibial plateau surface.

1.2 Mechanism of damage and consequences

- Direct mechanism: When the knee is straightened, the force acts

on the upper tibia posteriorly, causing damage to the PCL and PLC

- Indirect mechanism: When the knee is hyperextended and valgus

or when the knee is flexed and externally rotated

1.3 PCL and PLC classification

1.3.1 PLC classification.

* Classified according to time: Acute, subacute, chronic.

* Based on the lesion structure of the PLC:

Board Chapter 1 LITERATURE REVIEW.1 Classification is

based on the lesion structure of PLCClassification External rotation Damage structure

Type A Tibia external rotation increases

1.4 Diagnosis of PCL and PLC lesions

1.4.1 Medical history

1.4.2.1 Clinical examination of the knee joint

* The external recurvatum test evaluate hyperextension and varus

of the knee joint

* Varus test was performed with the patient with his leg on the edge

of the examination table with the knee flexed 300 and compared withthe normal side A positive sign suggests LCL damage

* Dial test assess the degree of external rotation of the tibia on thefemur at 300 and 900 flexion positions The test shows signs of PLCdamage when the difference is 10-150 at 300 flexion position

* Posteriolateral drawer test performed with the knee flexed at 90degrees, the foot externally rotated 15 degrees, and the tibiaposterolaterally rotated

* Reverse pivot shift is a test to evaluate PLC instability

1.4.2 Diagnostic imaging

1.4.3.1 X-ray

1.4.3.2 Stress X-ray

- Varus gap on stress radiography.

- Posterior drawer in a kneeling position on stress radiography.

1.4.3.3 MRI

The sensitivity and specificity of MRI in diagnosing acutelesions of the PCL and PLC complex are very high, up to 98-100%

1.5. Treatment of PCL and PLC lesions

1.5.1 Conservative treatment

Indicated for grade I and II of PCL and PLC injuries, casesthat do not require surgery Treatment involves immobilizing the kneewith a cast or brace for about 4-6 weeks

1.5.2 Surgical treatment of PCL and PLC lesions

1.5.2.1 Surgical repair of PCL and PLC

It is a technique of direct suturing of the components of thePLC, often applied within the first 3 weeks after injury, but theeffectiveness decreases over time The result of repair failure uponrepair can be up to 38%

1.5.2.2 PCL and PLC recontruction surgery:

 PCL recontruction: Based on anatomy: One or two bundle.

 PLC reconrtruction:

- PLC recontruction is based on non-anatomy:: These are surgeries

through the fibula head to restore the LCL, PT, not the PFL Thesetechniques only interfere with the fibula head and femoral tunnel, notthe tibia The most commonly applied technique is the Larsontechnique Recently, the authors have applied and recreated themodified Larson method by drilling two femoral tunnels Two femoraltunnels, one for the LCL graft and one for the PT graft

- PLC recontruction is based on anatomy: Recovers all LCL, PT

and PFL This technique uses four tunnels (one tibial tunnel, onefibular tunnel and two femoral tunnels) to reconstruct threecomponents, based on the technique developed by LaPrade (2006)

1.6 Recontructive studies of PCL and PLC

1.6.1 In the world

In 1976, Hughstons first reported a clinical problem ofdamage to the posterolateral region of the knee joint In 2001, Larsonreported treatment of PLC with reconstruction of the LCL and PTusing autologous semitendinosus tendon using an S-shaped incision

In 2002, Laprade reported the technique of PLC reconstruction Full ofimportant components such as LCL, PT, PFL This technique uses twotendon strips as grafts, drilling one fibula tunnel, one tibial tunnel andtwo femoral tunnels In 2010, Wajsfisz reported that 21 patients (13men, 8 women) with lesions of PCL and PCL underwentreconstructive surgery of PCL and PCL according to the modifiedLarson for the results of the IKDC scale after surgery (4A, 11B, 6C)increased significantly compared to before surgery (1B, 12C, 8D) In

2013, Sung-Jae Kim reported 46 patients divided into 2 groups (22patients in group A: single PCL reconstruction and 24 patients ingroup B: PCL and PLC reconstruction), with a follow-up period of 24months, group B showed more positive results in posterior tibialdisplacement (group A, 0,16 ± 0,44 mm vs group B, -1,44 ± 0,74 mm),Lysholm and IKDC of group B were both higher than group A In

2023, Yoon H.K reported 49 patients (51 knees) with a follow-upperiod of 24 months divided into two groups (group A, single PCLrecontruction; group B, PCL and PCL recontruction) Clinical resultsshowed that the IKDC scale was higher in group B and the posteriortibial plateau displacement in group B was 3,8±2,1 mm, less thangroup A, which was 4,8±2,3 mm

1.6.2 In Viet Nam

To our knowledge, there have been many studies treatingisolated DCCS lesions with reconstructive endoscopic surgery Therehave been no studies on simultaneous treatment of DCCS and GSNlesions Most importantly, the application of anatomical research andthe effectiveness of surgery have not been widely evaluated Our studywill contribute to evaluating the effectiveness of this method

Chapter 2 RESEARCH SUBJECTS AND METHODS

2.1 The anatomy study of the PCl and PLC

2.2.1 Research subject

The knee from the cadaver donor was cryopreserved according tothe fresh cadaver preservation method at the Department of Anatomy -Pham Ngoc Thach University of Medicine

2.2.1.1 Selection criteria from cadaveric donors

- The cadavers must be 18 years old or older

- The cadavers is processed and stored fresh at -300C, thenthawed to room temperature before dissection

2.2.1.2 Exclusion criteria from cadaveric donors

Donated cadavers were not preserved and handled properlybefore dissection The knee joints have damage and pathologyaffecting the structure of PCL and PLC discovered during dissection

2.2 Clinical research

2.2.2 Research subject

Including 31 patients diagnosed with chronic PLC and PCLgrade III, assigned to have recontruction surgery with autologousgrafts: PCL with hamstring graft and PLC with longus peroneal graft

according to the modified Larson at Military Hospital 175 from June

2022 to January 2024

2.2.1.3 Selection criteria

Age 18 - 55 years old with PLC and PCL at grade III injury:+ XQ with varus stress >4mm, external rotation >100,anteroposterior displacement >10mm (compared to normal knee).+ MRI: Image of damage to PCL and PLC rupture Pain andinstability of the knee joint affect daily activities

2.2.3 Research methods.

Cross-sectional descriptive prospective study withlongitudinal follow-up, no control group The study evaluated surgicalresults based on clinical tests such as Lachman, anterior drawer, dialtest, varus test, X-ray,stress X-ray, and MRI Assess knee functionaccording to the scale of Lysholm and IKDC 2000

2.3 Processing research results

Data are processed according to medical statistical methodsbased on SPSS 20.0 software

CHAPTER 3:

RESEARCH RESULTS

3.1 Anatomical characteristics of the PCL and PLC in adult Vietnamese cadavers

3.1.1 General characteristics of the dissected knee joint

The ratio of male to female knee joints in the study was 22/8 Theaverage age of the donor is 66,93 ± 12,50 years old

3.1.2 Anatomical features of LCL

The average length is 59,36 ± 6,57 mm, the averagesmall diameter is 1,68 ± 0,52 mm, the average largediameter is 2,92 ± 0,87 mm The area of the attachmentpoint on the femur of LCL has an average value of 41,33 ±17,19 mm2, mainly located posteriorly inferior to thelateral epicondyle, 1,78 ± 4,41 mm below the lateralepicondyle, in the anterior-posterior direction about4,86 ± 2,57 mm posterior to the lateral epicondyle Thearea of the attachment point on the fibula is 33,55 ± 10,87

mm2 and 100% attaches below the tip of the fibula head

3.1.3 Anatomical features of PT

The average length is 33,50 ± 6,65 mm, the small diameter is 2,71 ±0,65 mm, the large diameter is 5,86 ± 1,23 mm, with a cross-sectionalarea in the middle of 17,85 ± 5,21 mm2 The average area of attachment point on the femur is 58,79 ± 16,23 mm2, and is alwaysposterior to the LCL attachment point and about 17,54 ± 7,54 mm