The dissertation will be defended in front of designated examining committee at University Time: hour 14 date 26 month 09 year 2020
The dissertation is available at the following libraries: - Viet Nam National Library - Library of Hanoi Medical University
1 INTRODUCTION Posterior cruciate ligament is an important ligament that helps to ensure a strong knee joint. Early diagnosis and treatment of posterior cruciate ligament lesions to prevent torn semilunar cartilage, which is necessary for osteoarthritis. The posterior cruciate ligament alternative surgical materials are tendon autograft, tendon allograft, composite graft. Tendon allograft used to regenerate ligaments is still the most common due to many advantages. However, the biggest drawback is the tendon size restriction, but tendon allograft overcomes this limitation. Studies of knee anatomy show that the cross-sectional size of posterior cruciate ligament is 1.5 to 2 times larger than cruciate ligament, which requires a graft large enough to reconstruct posterior cruciate ligament that is similar to equivalent to the original ligament size, so the current trend is that many surgeons choose Achilles tendon allograft to use as a graft. The current studies in Vietnam are mainly used by authors to tendon autograft for posterior cruciate ligament reconstruction. For the use of tendon allograft is less. But until now there have been no research reports using Achilles tendon allograft in particular to reconstruct posterior cruciate ligament. From that practice, we
conducted the project titled: “Studying the application of arthroscopic reconstruction of the posterior cruciate ligament of knee joint via laparoscopic surgery with use of tendon allograft ” with the two goals: 1. Describing clinical features, magnetic resonance imaging and x-ray imaging of knee joints with posterior cruciate ligament lesions of patients under arthroscopic posterior cruciate ligament reconstruction with Achilles tendon allograft. 2. Evaluating the results of arthroscopic posterior cruciate ligament reconstruction with tendon allograft.
2 The urgency of the Project The use of tendon graft kinetics to regenerate ligaments has been described in the literature since the 1980s and is mainly used to regenerate anterior cruciate ligament. Since then this material has been used more and more due to its advantages. Many authors study and draw conclusions that using the same type of ribbed material is similar to the use of autograft tendon. In the world, there have been many research works on tendon allograft in general and Achilles tendon used as graft to regenerate posterior cruciate ligament for very good results. In general, studies on the use of Achilles tendon allograft in deep cryopreservation have a small number of patients and follow-up time is not much. In Vietnam posterior cruciate ligament reconstruction surgery has been carried out in several large hospitals in Vietnam in recent years using autograft tendon. The use of allograft tendon to date has very few reported works and all have been used to reconstruct anterior cruciate ligament without any studies using Achilles tendon allograft to reconstruct posterior cruciate ligament. In view of the aforementioned situations, we carry out this project to contribute to affirm the advantages of using Achilles tendon allograft to reconstruct posterior cruciate ligament to help surgeons have more choices of materials and methods of surgery, which are suitable for each patient. New contributions of the thesis - The thesis has outlined the experience of using clinical and subclinical examination in diagnosis of posterior cruciate ligament lesions, applied in clear diagnosis and surgical indications for each specific patient group. - Assessing the Achilles tendon size of Vietnamese people in accordance with posterior cruciate ligament shaping with knee diameter of 9.14 ± 0.45mm and a length of 15.3 ± 1.49mm. State the treatment method for Achilles tendon allograft, orienting the selection of graft diameter suitable for each specific patient group. - Completing the steps in posterior cruciate ligament reconstructive laparoscopic surgery with a piercing technique. Experience in selecting
3 bone tunnel drilling site, graft technique and graft fixation in bone tunnel. - Arthroscopic posterior cruciate ligament reconstruction with tendon allograft has good results when evaluated clinically and subclinically, can be compared with other tendon autograft. Using allograft offers advantages such as shortened surgery time, small surgical scars, less pain and ease of rehabilitation after surgery. During the time of monitoring and evaluation, there were no signs of infection, infection or discharge of tissue transplant. The thesis structure The thesis has 134 pages, including the following parts: Introduction (3 pages), Literature overview (33 pages), Research subjects and methods (28 pages), Research results (30 pages), Discussion (37 pages), Conclusion (2 pages), Recommendations (1 page). The thesis has 28 tables, 55 figures, 11 charts, 158 references (138 references by foreign authors and 20 references by domestic authors). Chapter 1 LITERATURE OVERVIEW 1.1. Posterior cruciate ligament surgery Posterior cruciate ligament goes from the front half humerus the femur runs down to the back and out, clinging to the back of the tibia. posterior cruciate ligament consists of 2 bundles: first bundle after outside
Humerus Posterior and interior muscle Anterior and posterior muscles
Figure 1.3. Photo of 2 bundles of posterior cruciate ligament in profile * Source: according to Wolfgang Johannes (2010) Posterior cruciate ligament 13mm thick, thick front and outside bundles, 34.5 ± 1.95 mm long and back bundles in pieces, 32.8 ± 1.95 mm long, stretched when folded 90º and almost sagging when the knee
4 was extended. The average length of posterior cruciate ligament is 38 mm. The posterior cruciate ligament is the narrowest in the middle, with an average width of 11 mm and a tapering taper from the grip point of 32 mm to the grip point of 13.4 mm. The posterior cruciate ligament grip at the thigh stretches from 12 o'clock to 4 o'clock clockwise for the right knee and at 8 o'clock counterclockwise for the left knee. The point of the muscular tendon on the thigh of the anterior bundle extends from 12h00 to 2h30 in a clockwise direction for the right knee joint and to the position of 9.30 anticlockwise for the left knee joint. In tibia: Tibial attachment site area of the first and the last bundle is respectively 84.5 ± 12.52 mm2, 47.8 ± 6.20 mm2. The distance from the edge of the articular cartilage plane to the tibial attachment site posterior cruciate ligament and the posterior margin below the tibial attachment site of posterior cruciate ligament is 9.7 ± 1.73 mm and 13.6 ± 0.96 mm. 1.2. Causes, mechanism of posterior cruciate ligament fractures The causes of posterior cruciate ligament injury are listed by many authors as the main causes are sports accidents, traffic accidents, labor accidents, and domestic accidents. There are three main mechanisms of posterior cruciate ligament damage: trauma to the front of tibia, over-folding, stretching. 1.3. Lesion classification of posterior cruciate ligament - Classification by time: Based on the time of trauma, posterior cruciate ligament lesions are divided into acute, subacute and chronic forms. - Classification according to position of injury: Based on the position of injury of posterior cruciate ligament is divided into 3 types: Middle central cut, top cut, lower cut. - Classified by level of injury: Based on the degree of damage to many authors have identified the posterior cruciate ligament damage in two types: Orphan totally, not completely off.
5 1.4. Examination and diagnostic tests Clinical test: Based on the following drawer signs, Godfrey’s test, Quadriceps active test. Sub-clinical test: This includes conventional X-ray in the acute phase usually detecting lesions in the attachment site of posterior cruciate ligament. Reverse Segond fracture. X-ray of drawer after quantification using Telos frame to assess the degree of displacement of tibial plateau. Nuclear magnetic resonance imaging: This is a very significant method in diagnosis. Manifestations of posterior cruciate ligament lesions on Nuclear magnetic resonance imaging include: Unknown ligament shape, only one ligament, fracture images, edema images and bone attachment points.
Figure 1.21. Image of posterior cruciate signal loss ligament (white arrow position) * Source: according to Ali Naraghi (2014) 1.5. Treatment of posterior cruciate ligament lesions Surgical treatment for patients with posterior cruciate ligament lesions in the acute phase is indicated for patients with coordinated lesions such as bone damage, cartilage damage causing joint jam ... priority surgery Treat possible causes of complications. As for the posterior cruciate ligament lesions alone or in combination, there is no risk of acute phase complications usually requiring conservative treatment. Indications for surgery: For posterior cruciate ligament adhesion lesions, the authors recommend early treatment and surgical fixation. Patients with posterior cruciate ligament fractures of grade III or II have rehabilitated but still show signs of loose knee. No serious complications of osteoarthritis (grade III, IV), no restriction of knee stretching, no infection arthritis.
6 Classification of posterior cruciate ligament regeneration techniques Classification of posterior cruciate ligament regeneration techniques
Advantages and disadvantages of Achilles tendon graft in ligament regeneration The use of Achilles tendon allograft as a graft to regenerate ligaments has the following advantages: Because it does not take time to remove the tendons, the surgery time is reduced. Active graft size. No local injury to the tendon, and better aesthetic factor because it does not have to take tendons, so the incision is smaller and can regenerate many ligaments at the same time. Not taking tendons, so it does not affect the muscles, does not cause pain and numbness in the tendon area. There is a piece of heel bone, so the ability to connect bones and bones in the tunnel is good, and the ability to fix the graft in the tunnel better allows the application of early and positive rehabilitation programs after surgery. The disadvantages of using Achilles tendon allograft are increased surgical expenses, risk of disease transmission and the risk of graft elimination.
7 Chapter 2 RESEARCH SUBJECTS AND METHODS 2.1. Research subjects The subjects of the study were posterior cruciate fracture ligament fractured patients who came for examination and received reconstructive surgery with Achilles tendon allograft at Vietnam Sports Hospital. 2.2. Criteria for choosing studied patients Selection criteria - Patients over 16 years old and under 55 years of age regardless of gender or occupation. - Undergoing a posterior cruciate ligament reconstruction surgery using Achilles tendon allograft (provided by Department of Tissue Preservation, Department of Embryology, Hanoi Medical University). Exclusion criteria for studied patients - Patient has posterior cruciate ligament fracture with anterior cruciate ligament rupture, same lateral ligament. - Patients who are not qualified for surgery: suffer from muscular atrophy, limiting the amplitude of knee movement after injury. - Patients with posterior cruciate ligament reconstruction surgery do not use Achilles tendon allograft. 2.3. Time and place for conducting the research The study was conducted at the Vietnam Sports Hospital between May 2011 and May 2019. 2.4. Research Methods The study was designed using a prospective research method and a retrospective study of clinical intervention without control. Convenient sample size: Select all eligible patients according to patient selection criteria during the study.
8 Patient visits with pain, loosed/limited mobility of the knee joint
- Clinical examination - X-ray, magnetic resonance imaging of knee joint
Diagnosis to identify posterior cruciate ligament fractures
- Following T0; T1 - Following re-examination T3, T6, T12,Tn
Collection of clinical and subclinical characteristics (all patients included in the prospective and retrospective patient group)
Perform plastic surgery posterior cruciate ligament by endoscopy using tendon allograft; Evaluate the results of treatment for prospective patients
Invited to participate in the research
Sign a voluntary commitment
Indications for laparoscopic surgery by Achilles tendon allograft
Diagram 2.1. Research process 2.5. Posterior cruciate reconstruction surgery of knee ligament with Achilles tendon allograft Preparing the tools and means: Endoscopic arthroscopy apparatus: light source, camera ... Tendon tension instruments, electric drills, drill bits of sizes, Staple guide nails, bio-size screws. Preparing materials for making graft Material used to make graft is Achilles tendon allograft piece with piece of heel bone provided by Department of Tissue Storage, Department of Embryology, Hanoi Medical University.
9 Preparing the patient Anesthesia: The patient received spinal anesthesia with Marcain in combination with Fentanyl. Reconstruction of posterior cruciate ligament by 1-bundle Achilles tendon allograft technique: Endoscopy on joints assess lesions: Using 3 entrances are the front entrance in the M (medial, horizontal joint of knee joint, close to the edge of the kneecap), the front entrance outside (L: lateral, transverse joint, near the outer edge of the kneecap) and the entrance on later in. Identify location, morphology of posterior cruciate ligament, coordinated lesions and other joint components. Broken posterior cruciate ligament
Figure 2.2. Endoscopy assesses damage * Source: photos of studied patients (code BA1901NCT78) Preparing the ligament graft: The Achilles tendon allograft after being removed from storage is thawed. Graft small heel bone to leave a piece of bone with diameter equal to the diameter of graft that the surgeon expected to choose to recreate posterior cruciate ligament for patients about 1.5 - 2 cm in length. Cut the Achilles tendon filter to shape the graft, the diameter is equal to the diameter of the heel bone, the length of the graft depends on the length of the Achilles tendon piece.
Figure 2.3. Achilles tendon graft (A) and ligament graft (B) * Source: photos of studied patients (code BA1901NCT78)
10 Making tibial tunnel: Reveal the tibial attachment site of posterior cruciate ligament until you see the upper edge of the hamstrings; stop (the lower edge of posterior cruciate ligament is exposed to the upper edge of the tendon), try to retain the ligament part left over at the grip.
Figure 2.6. Reveal the tibial attachment site of posterior cruciate ligament until you see shore on popliteus tendon. *Source: photos of studied patients (code BA1936NCT5/2018) Placing the positioning frame on the tipping point to select the center of the tunnel is the posterior cruciate grip point. Drill the directional nail with a diameter of 2 mm from front to back to create an angle of 450 tibial plateau surface, when the nail has just come out of the bone body at the posterior cruciate ligament sticking position, stop, remove the positioning frame.
Figure 2.7. Drilling to position the tibial tunnel *Source: photos of studied patients (code BA2615NCT07/2018) Drilling the tibial tunnel piercing from the front of the tibia to the back according to the guide nail, the diameter of the drill is equal to the diameter of the graft.
Figure 2.8. Drilling to position the tibial tunnel *Source: photos of studied patients (code BA2615NCT07/2018) Insert a thread waiting from outside to match through the front entrance to the rear compartment, use Cloward to thread into the tibial tunnel from the peripheral end to pull the waiting thread end out. Making femoral tunnel: The position of the femoral tunnel center is determined in correspondence with the position of the center of the posterior cruciate ligament, at 11 o'clock for the left knee and 1 hour for the right knee, 7-8mm from the edge of the articular cartilage. Insert the positioning frame into the joint drive through the front inlet into the position to be determined as the center of the femoral tunnel, drill with 2 mm diameter diameter according to the position and direction of the positioning device, drilling from outside to inside.
Figure 2.9. Drilling the femoral tunnel *Source: photos of studied patients (code BA2615NCT07/2018) Using hollow bore bore with a diameter equal to the size of the femoral tunnel drilling piece, put through the front entrance outside, drill from the inside out under the direction of the guide drill, drill from the inside to the bone outside. Thread the graft and fix the graft in the tunnel: Put the knee in a 900 fold position, Push the graft into the joint through the front entrance
12 outside until the graft is completely in the joint, then stretch the ends of the ribs to suture the outside of the two tunnels. Screw into the tunnel to fix the graft using Staple to fix the suture part just outside the tunnel.
Figure 2.13. Reconstruted posterior cruciate ligament graft *Source: photos of studied patients (code BA2615NCT07/2018 ) 2.6. Data processing methods The following data were collected by using biomedical statistical algorithm with the support of IBM SPSS 20.0 software and R software version 3.4.1. runs on Microsoft Windows 10 operating system platform.
Chapter 3. RESEARCH RESULTS 3.1. General characteristics of studied patients Table 3.1. General characteristics of studied patients Quantity Characteristics Rate % p (n=36) 16 – 30 22 61,1 Age group 31 – 45 13 36,1 <0,05 >45 1 2,8 The average age 29,69 ± 6,2 ̅ ± SD (years old) (Max = 54, Min =17) Male 31 86,1 Gender <0,05 Female 5 13,9
13 3.2. Clinical characteristics 3.2.1. Traumatic characteristics of posterior cruciate ligament Table 3.2. Traumatic characteristics of posterior cruciate ligament Quantity Rate Lesions of posterior cruciate ligament p (n=36) % 20 55,6 Left >0,05 Hurt side Right 16 44,4 15 41,7 Sports accident Traffic accidents 7 19,4 >0,05 Causes Labor accident 9 25,0 Living accident 5 13,9 19 52,8 Force exerted from the front Mechanism Too fast 4 11,1 >0,05 of injury Stretching 5 13,9 Unknown mechanism 8 22,2 Comments: There were 55.6% of posterior cruciate ligament lesions on the left leg, the proportion of posterior cruciate ligament lesions on the right leg was 44.4%. The cause of posterior cruciate ligament injury from sports accidents was seen in 15 patients (accounting for 41.7%). Traffic accidents and occupational accidents were 7 patients and 9 patients respectively accounting for 19.4% and 25%. 3.2.2. Symptoms of mechanical energy Loose joints + arthralgia + thigh muscle atrophy + limited amplitude of motion Loose joints + arthralgia + thigh muscle atrophy
8,3 25 36,1
Loose joints + leg muscle atrophy
Loose joints + joint pains
Chart 3.1. Major functional symptoms (n = 36)
14 Comments: The proportion of patients who had 4 functional symptoms: pain, loose joints, muscle atrophy and limited mobility were 8.3% of studied patients. The proportion of patients with loose joints and thigh muscle atrophy accounted for the highest proportion with 36.1%; the lowest in the group appeared only loose joints merely with 13.9%. 3.2.3. Clinical symptoms assessed knee joint instability among studied patients Table 3.3. Physical symptoms Test Posterior drawer (+) Quadriceps muscle (+) Godfrey (+)
Quantity (n=36) 36 36 36
Rate % 100 100 100
Comments: At the time of admission, the posterior cruciate ligamentrelated knee instability tests were found in 100% of studied patients. 3.3. X-ray imaging and magnetic resonance characteristics of knee joint 3.3.1. X-ray imaging characteristics In the studied patients group, there were 2 of 36 patients accounting for 5.6% of posterior cruciate ligament lesions, no patients with segon lesions. 01 patient with bone cartilage defects under femoral cartilage manifested on conventional X-ray film accounted for 8.4%. 3.3.2. Tibial plateau deviation prior to surgery on X-ray film using Telos traction frame Table 3.4. The lateral tibial plateau deviation compared to the thigh bridge convex on XQ film using Telos truss (n = 36) Deviation (mm) 0-5 6-10 > 10 Total
Number of patients 0 5 31 36
Rate % 0 13,9 86,1 100
15 3.3.3. Result of magnetic resonance imaging of knee joint Table 3.5. Image characteristics of magnetic resonance film (n=36) Magnetic resonance image of posterior cruciate Quantity Rate % ligament of knee joint The shape of the ligament is unknown. 11 30,6 Signs of 11 30,6 injury in Photos of loose cuts posterior Pictures of edema. 6 16,7 cruciate Posterior cruciate ligament slack. 6 16,7 ligament Bubbles stick to tibia. 2 5,6 Posterior cruciate ligament completely 28 77,8 broken Degree of Posterior cruciate ligament partly injury 6 16,7 fractured Bubbles stick to tibia. 2 5,6 Bone marrow edema Indirect 11 30,6 sign Tibial plateau lags behind the thigh bone 13 36,1 Normal posterior cruciate ligament 25 69,4 fracture Posterior ligament posterior fracture + 4 11,1 medial meniscus tear Normal posterior cruciate ligament Combined 2 5,6 fracture + lateral meniscus tear injury Normal posterior cruciate ligament fracture + medial and lateral meniscus 1 2,8 tear Posterior cruciate ligament sprain 2 5,6 Degeneration of joint cartilage damage 2 5,6 3.4. Technical characteristics of posterior cruciate ligament reconstruction surgery by Achilles tendon allograft 3.4.1. Characteristics of tendon allograft
16 Table 3.6. Characteristics of tendon allograft (n=36) ̅ ± SD Index Min 9,14 ± 0,45 8,5 The size of the tendon Diameter (mm) draft obtained Length (cm) 15,3± 1,49 11,5 Diameter (mm) 8,94 ± 0,27 8,5 Size of tendon ligament draft Length (cm) 13,55 ± 0,82 11 Time of taking graft → be grafted
< 3 hours (n, %)
≥ 3 hours (n, %)
Max 11 24,1 9,5 15,2
3.4.2. Survey results of femoral tunnel and tibial tunnel
Table 3.7. Characteristics of femoral tunnel and tibial tunnel (n=36) Diameter (mm)
Index Femoral tunnel Tibial tunnel
̅ ± SD 8,94 ± 0,27 8,94 ± 0,27
Min 8,5 8,5
Max 9,5 9,5
3.5. Accident during surgery: In the study, there were no complications in surgery such as: screw fracture, tunnel rupture, vascular - nerve damage ... 3.6. Surgical results 3.6.1. Assessing the patient's condition at the time of discharge Table 3.8. Results of evaluating the patient's condition at the time T1 (n=36) Number Rate Assessment of patients % 2,36 ± 0,72 Pain site VAS ̅ ± SD (site) (Min = 1; Max= 3) The incision is dry, from the beginning 36 100 Incision condition Swelling, redness, drainage 0 0 Average Hematocrit (l/liter) 0,36 (0,35 – 0,46) Total Average hemoglobin (g/liter) 129 (126 - 1430 blood test Quantity of average white blood cells index 9,1 (7,4 - 9,4) (x109/liter)
17 Average red blood cells (x1012/liter) Ultrasound No spillage (n, %) Little level (<30 ml ) (n, %) of knee joint Moderate level (30-60ml) (n, %) effusion Severe level (>60ml) (n, %)
4,2 (4,0 – 5,7) 9 (25) 16 (44,4) 11 (30,6) 0 (0)
Comments: The percentage of patients who had the first surgical incision during the postoperative period at the Hospital reached 100%. VAS pain points at the time of discharge ranges from 1-3 points. 100% of patients at the time of discharge had no fever, blood count tests were within normal limits. 3.6.2. Evaluate the results of treatment at the time T3 and T6 and T12 Table 3.9. The change of examination tests at the time of T3 and T6 Test
Decrease * (n; %)
Time T3 Posterior drawer (+) 11 35,5 20 (64,5) Quadriceps muscle (+) 0 0 31 (100) Godfrey (+) 0 0 31 (100) Time T6 Posterior drawer (+) 8 25,8 23 (74,2) Quadriceps muscle (+) 0 0 31 (100) Godfrey (+) 0 0 31 (100) (*)Compared to the time before surgery Comments: Clinical examinations have significant changes over time. Changes in knee joint function Lyshom score scale: Evaluation of knee joint function after 6 months of surgery shows that most functions are very good and good accounting for 80.7%. Knee joint function after surgery was on average 16.1%, which was bad grade, accounting for 3.2%. The average Lysholm score is 89.7 ± 6.4. Objective IKDC scale: Assessing the strength of knee joint according to IKDC after 6 months of surgery showed that 77.5% of type A ranked B
18 accounted for 19% of type B, type C accounted for 3.2%. Compared to the time of admission, knee joint function has clearly improved. There were differences between groups and the difference was statistically significant with p <0.05. The displacement of tibial plateau compared to the femoral bulge on Xray with Telos frame The number of 31 patients who were examined after 6 months was taken X-ray image using a Telos frame, resulting in a posterior tibial plateau difference of posterior cruciate ligament compared to an average healthy knee of 3.7 ± 1.6 mm. 3.6.3. Test results at 12 months after surgery (T12) Results of clinical trials: Table 3.10. Clinical test at the time T12 (n = 20) Rear drawer sign Degree of injury
Number of patients (n = 20)
16 4 0 0 20
80 20 0 0 100
Negative Degree I Degree II Degree III Total
Evaluate the level of posterior tibial plateau slippage difference posterior cruciate ligament before and after 12 months surgery by KT 1000 device Table 3.11: Comparison of posterior tibial plateau slide compared to femoral protrusion at T0 and T12 on X-ray film with Telos frame Time T0 (n=36) Time of evaluation T12 (n=20)
Average (mm) ± SD 13,2 ± 2,3 3,1 ± 0,7
Max – min (mm) 7,5 - 19 0-5
Value p < 0,001
19 Comments: At 12 months postoperative evaluation, the posterior tibial plateau sliding posterior posterior cruciate ligament on X-ray with Telos frame average of 3.1 ± 0.7 mm, before surgery was 13.2 ± 2.3 mm. With p <0.001 the difference is statistically significant. Evaluating the knee joint function on Lysholm scale: At the time of assessment T12 points, the average Lysholm score is: 91.6 ± 6.1 points. The rate is very good and good, reaching 85%, 3 cases with an average of 15% and no poor results. Classification of stability according to IKDC: Results according to the IKDC score scale, type A accounting for 85%; type B 15%, no case ranked type C and type D. CHAPTER 4: DISCUSSION 4.1. Discussing the clinical features and X-rays and nuclear magnetic resonance imaging of knee joints 4.1.1. Clinical characteristics before surgery All patients have symptoms of pain and swelling that limit knee joint movement immediately after injury, the degree of swelling and pain of the knee depends on each patient, depending on the traumatic situation. Post-traumatic knee pain is a common symptom of a closed knee injury, not a sign of ligament damage. After the patient had gone through a swollen stage, the knees were able to move normally during their daily activities, they all noticed weak and loose knee joints, the fear of dislocating their knees when doing forceful movements to the knee joint. love. Post-drawer drawer positive signs in all patients of which grade III positive was 77.8% positive grade II was 22.2% (chart 3.3). This result is similar to the research of Pham Quoc Hung, Phung Van Tuan, Tang Ha Nam Anh ... According to Clancy Jr. et al (1999), the sign of the posterior drawer is the most important to decide whether posterior cruciate reconstruction surgery or not. It is important to note that the correlation between the anterior shore tibial plateau and the inner femoral convex examination must be determined. The preoperative knee function in our study was assessed on a Lysholm and IKDC 2000 scale. In this study, there was no case that the Lysholm score was good and very good. bad Lysholm score accounted for 83.9%, the group with average knee joint function accounted for 16.1%. The average Lysholm score of patients in the NC group was
20 62.0 ± 4.9, which is equivalent to the research result of Do Van Minh of 69.3 ± 7.62, higher than the author Luong Trung Hieu. before surgery was 51.09 ± 16.87, Tran Trung Dung was 63.8 ± 4.2. In our study, 100% of patients with objective IKDC classification before surgery (at the time of T0), category C accounted for 32.2% and type D occupied 67.8%. Compared with the results of Luong Trung Hieu's study, classification of knee stiffness according to IKDC before surgery had 91.3% of grade D, 8.7% of grade C. The author Do Van Minh reported 88.1% patients with level D and 11.9% of patients with level C. 4.1.2. Features of X-ray and nuclear magnetic resonance imaging Characteristics of lesions on conventional optical film: In the study patient group, all 36 patients were given conventional x-ray images of oblique position to assess damage before surgery. As a result, no patient had segon lesions. 8.4% of patients displayed signs of osteoarthritis grade I according to Kellgren and Lawrence's degree on conventional X-ray. In acute posterior cruciate ligament lesions, knee X-ray imaging usually does not detect knee osteosarcoma except for posterior cruciate ligament adhesion. On X-ray images of tilted knee, we can detect the image of the posterior attachment site of posterior cruciate ligament as well as assess the displacement of the attachment. A majority of the authors noted that the posterior cruciate ligament attachment site is more common than the posterior cruciate ligament adhesion.. Characteristics of lesions on quantitative X-ray film: In this study all patients had X-rays taken using the Telos frame. There are 5/36 patients with tibial plateau deviation from 6-10mm accounting for 13.9%. There were 31/36 patients with tibial plateau deviation> 10mm, accounting for 86.1%. The average tibial plateau deviation is 13.2 ± 2.3mm highest 19 mm, the smallest is 7.5mm. The degree of displacement of tibial plateau compared to the femoral convex in our study is similar to that of Seon et al., 7 ± 2.01mm, Norbasksh et al is 12 ± 3.9mm ... but lower than Cristián A. Fontboté … Characteristics of posterior cruciate lesions ligament on nuclear magnetic resonance imaging film: In this study, posterior cruciate ligament lesion on nuclear magnetic resonance film is also very common, the unknown ligament shape accounts for 30.6%, the
21 ligament tear is 36.1% and the sign is signal of localized signal increased by 16.7%. In 69.4% of patients with posterior cruciate ligament rupture alone, the remaining patients had joint cartilage tear injury or articular cartilage injury. In which 11.1% of patients had posterior cruciate ligament rupture associated with medial meniscus tear, 5.6% of patients had posterior cruciate ligament associated with external meniscus tear, 2.2% of patients had posterior cruciate ligament associated with torn cartilage both inside and outside meniscus. In the diagnosis of SC tear, the rate of SC tear is higher than the external SC, this rate is also consistent with Bui Van Lenh (2006). 4.4. Discussing posterior cruciate ligament regeneration technique by Achilles tendon allograft 4.4.1. Choosing Achilles tendon graft The question of whether a tendon of the same type or a tendon autograft in knee ligament reconstruction surgery remains controversial. The advantages of autologous graft are: there is no risk of infection, the source is safe and reliable, however, when taking a tendon autograft, the surgery time is longer, more surgery, the risk of infection, pain At the place of tendon extraction and especially limited in size of graft tendon The advantage of similar grafting is that there is no need for additional incision, proactively desired graft size, shortening the surgery time and especially in the case of multiple ligament damage. However, its disadvantage is the extra cost, the risk of disease transmission, the graft tendon to necrosis or bacterial infection. Currently, in the world, many authors advocate the use of graft lines such as Achilles, patella, patella, lateral tibial, posterior tibial plateau ... because they have the advantage of not causing further damage to patients. stable size, shortened surgical time, giving very good treatment results ... in which Achilles tendon allograft is commonly used to reconstruct posterior cruciate ligament by the technique "trans tibial plateau tunnel" because both ensure certainty, just ensure the rib length. 4.4.2. Ligament graft size For posterior cruciate ligament plastic surgery, the need for a graft that is large enough and strong enough to play an important role and determines the success of surgery. Some authors use tendon allograft such as Tran Trung Dung (2014) using Hamstring tendon graft
22 with average diameter of 6.4 ± 0.7mm (from 6.0 to 7.0mm) and average length of 11, 5 ± 3.5cm (9.5 - 13 cm); of Pham Quoc Hung (2014) with a diameter of 6.0 - 8.0 mm, a maximum of 7 and 7.5 mm and a length of 9.5 - 11 cm, of Phung Van Tuan (2014) with a diameter of 6, 0 - 8.0mm and the average length is 11.88 ± 0.90cm (from 9 - 13cm). The average piece of Achilles tendon allograft of Vietnamese in Tran Trung Dung's study has a diameter of 10.32 ± 0.64mm, which is 9.14 ± 0.45cm. This size allows creating a graft with a diameter larger than the diameter of the graft itself. With this size, the maximum diameter of the graft can be reached is over 10mm, however, in clinical practice, we find that the knee joints of Vietnamese people are small, the narrow bridge is so narrow to avoid graft too big. "impingement" syndrome with the surrounding structure we selected graft diameter used is 8.5mm, 9mm and 9.5mm. 4.4.3. Evaluating the knee joint function after surgery At the time of 6 months after surgery: We monitored and assessed the results on 31 patients. The average Lysholm score is 89.7 ± 6.4 points, the lowest is 64 points in which the very good ranking accounts for 29% of the good grade, accounting for 51.7% of the average, accounting for 16.1% and the poor is 3.2%. There were 74.2% of patients had negative signs after the drawer, 25.8% of patients had positive signs after the drawer. Godfrey test and posterior subsidence test were negative in 100% of patients. According to IKDC, there are 77.5% of patients rated A, 19% rated B and 3.2% of patients rated C, none of patients ranked D. Measure the posterior displacement of tibial plateau average is 3.7 ± 1.6 mm, at most 6 mm, at least 0 mm. At the time of 12 months after surgery: The average Lysholm score is 91.6 ± 6.1 points; the lowest is 66 points and the highest is 100 points. Very good and good percentage accounted for 85%, on average 15% (Table 3.19). There were 20% found signs of a drawer after the positive degree I. In which all patients before surgery showed signs of drawer after positive level II have this negative sign after surgery, with regular knee joint function at a very good level according to Lysholm and A class according to IKDC. The classification of rehabilitation according to IKDC at the time of 1 year after surgery, 85% of patients rated A, 15% of patients rated B did not have any patients rated C, D. The measured displacement after of the average tibial plateau is 3,1 ± 0,7 mm.
23 Comparing the results of studies on Achilles tendon allograft materials used as graft to recreate posterior cruciate ligament for results in the world. In 2009 Sung-Jae Kim studied 25 posterior cruciate ligament rupture patients who were regenerated with Achilles tendon allograft. The average Lyshom score was 86.8 ± 7.53. In 2015 Sinan Zehir conducted posterior cruciate ligament reconstruction with Achilles tendon allograft with an average follow-up time of 14.27 ± 6.7 months. posterior tibial plateau glide level compared to femoral bridge is 2.45 ± 1.8mm. CONCLUSION 1. Clinical characteristics, magnetic resonance and x-ray images at knee joint where posterior cruciate lesions have been indicated for surgery The most common functional symptom is a loose joint accounting for 100%. There are also symptoms of muscle atrophy, joint pain. The posterior drawer positive sign is 77.8% and the second degree is 22.2%, the Godfrey sign is positive in all patients. The average Lysholm knee joint function of patients in the EL group was 50.13 ± 9.89. Objective IKDC classification before surgery showed 55.6% was ranked type A and 44.4% ranked type B. X-ray imaging characteristics As a result, no patient had Segon lesions. 5.5% of patients displayed signs of osteoarthritis on conventional X-ray. All patients had loose knee with lateral lateral displacement on X-ray film using Telos frame, tibial plateau deviation of 13.2 ± 2.3 mm. Posterior cruciate ligament vulnerability trait on nuclear magnetic resonance imaging The most common posterior cruciate ligament lesion on magnetic resonance imaging is 30.6% ligament shape and 30.6% fracture image. 77.8% of patients had posterior cruciate ligament complete rupture on magnetic resonance film images. 2. The result of posterior cruciate ligament reconstruction surgery by Achilles tendon allograft: The largest diameter of graft is 9.5 mm, the smallest is 8.5 mm. The average graft diameter is 8.94 ± 0.27 mm.