Knee ligaments are important stabilizing structures that ensure normal knee motion. Improperly treated knee ligament injuries can lead to knee instability and affect joint function, and secondary damage to intra-articular structures can exacerbate joint damage. Therefore, the repair and reconstruction of knee ligament rupture is particularly important to restore the stability and function of the knee joint.
In recent years, the structural function of the knee joint has been studied in depth from various aspects such as tissue anatomy, ultrastructure, biomechanics and dynamics, especially the study of ligament injuries has made great progress. Clinically, with the development and application of modern minimally invasive arthroscopic surgical techniques, the traditional open surgery for repair and reconstruction of ligamentous ruptures in the knee joint has been gradually replaced by arthroscopic surgery, and the surgical methods have been continuously improved, with significantly higher clinical efficacy.
Simple ligament injury of the knee is divided into 3 degrees according to the degree of injury: degree I: limited to the tear of a few ligament fibers, local pain, and no change in joint stability. Degree II: most of the ligament fibers are torn, the local reaction is heavy, the functional limitation is obvious, but the impact on the stability of the joint is not significant. Degree III: complete rupture of ligaments.
Grade III injuries can be further divided into mild instability (5 mm, +), moderate instability (5-10 mm, ++) and severe instability (>10 mm, +++) according to the degree of joint surface displacement measured by stress test after ligament rupture. Conservative treatment is required for Ⅰ and Ⅱ degree injuries, and conservative treatment is also available for mild instability of simple lateral collateral ligament rupture, with plaster immobilization for 4-6 weeks and strengthening of quadriceps exercise, which can also receive good results. If the lateral collateral ligament and surrounding tissues are heavily damaged, obviously unstable, or combined with cruciate ligament or meniscus injury, then surgery should be promptly repaired.
1, medial collateral ligament injury of knee joint
The medial collateral ligament of the knee is a thickened part of the fibrous layer of the joint capsule, which is a flat and wide triangle with a forward base, divided into two layers. The deep layer is shorter and is part of the joint capsule, the capsular ligament, and is connected medially to the meniscus; the superficial layer is longer and starts near the medial tuberosity of the medial femoral condyle and ends obliquely inward at the medial surface of the upper tibia, with the lower end point at the deep side of the goose metacarpal tendon, medial to the tibial tuberosity, and 2 to 4 cm below the tibial articular surface. The anterior fibers of the superficial layer of the medial collateral ligament are longitudinal and downward, called the anterior bundle; the posterior fibers are shorter, called the oblique bundle, which is divided into the superior and inferior oblique bundles, which intersect the knee joint edge obliquely and inferiorly, respectively. The medial collateral ligament of the knee joint has the function of maintaining joint stability and regulating joint movement, and its tension varies with the position of the joint.
In full flexion, the anterior bundle of the ligament is tense and the posterior bundle is relaxed; in half flexion, the anterior and posterior bundles are relaxed, and in full extension, all ligaments are tense. Therefore, the medial collateral ligament is most susceptible to injury in the semi-flexed position of the knee. In addition, when the ligaments are tense, the nerve reflexes cause the muscles around the knee to contract, thereby strengthening the stability of the joint. If the ligament is torn at the end or heals in a relaxed state, the knee joint will lose this neuromuscular reflex and increase joint instability.
1.1 Acute medial collateral ligament injury
A complete rupture should be surgically repaired with sutures to restore stability to the severed end. It is important to emphasize that a rupture of the inferior end of the medial collateral ligament, where the severed end is pulled out of the crevice between the goose foot and the tibia, is unlikely to be repositioned by conservative treatment. In addition, the medial surface of the tibia is cortical bone, which has a smooth surface and is difficult to heal with the severed end; therefore, early surgical treatment is even more important. If the medial collateral ligament of the knee alone is ruptured, the ligament should be repaired directly; if it is combined with intra-articular injury, the intra-articular (arthroscopic if available) should be explored and treated first, and then the medial collateral ligament should be repaired.
1.1.1 Repair of the upper stop and body rupture Use No. 4 silk or polyester braided thread to repair the broken end directly by butt-end or overlapping sutures; if the rupture is combined with an intra-articular injury, the medial collateral ligament should be repaired first.
If the upper stop rupture is an avulsion rupture, the severed end needs to be sutured superiorly (“U” suture or “8” suture) on the periosteum; for avulsions with bone blocks, screws or tooth washers can be used to fix the bone blocks when they are large, and the bone blocks when they are small can be fixed with a Kirschner Needle with suture fixation, can be drilled on the bone surface and sutured with polyester braid.
1.1.2 Repair of lower stop fracture Since the lower stop is attached to the smooth and hard inner side of the upper tibia, the fracture is mostly
The broken end is difficult to be fixed directly, so it needs to be reconstructed (fixed after embedding the broken end into the bone hole). The method is: in the deep side of the goose foot (horizontal incision of the goose foot into the more convenient operation) at the lower stop of the medial collateral ligament along its direction of travel with a bone drill on the bone surface to open the bone hole to the medullary cavity, and then in the distal end of the bone hole to drill two bone holes with the bone hole, using polyester braided suture to knit the broken end and then introduce the broken end into the bone channel, two sutures through the bone hole to draw tightly knotted fixed. Breaks with avulsed bone blocks can be repaired by in situ fixation with screws with tooth washers.
1.2 Old medial collateral ligament injury of the knee
1.2.1 Ligament superior stops and body ruptures with extended lax healing can be operated on with superior stops. During surgery, the size of the bone block is determined according to the width of the ligament and the extent of the attachment, and then the bone block with the ligament attachment is chiseled (usually about 2 cm × 2 cm in size), and then the ligament is loosened along the anterior and posterior edges of the ligament along with the joint capsule, starting from above the ligament, until the joint gap level can be tightened by displacing the ligament forward and tightening the bone block with the ligament upward, and tightening the medial collateral ligament (usually upward). The medial collateral ligament is tightened (usually 1 to 1.5 cm), and then the bone is embedded and fixed with cancellous bone screws after slotting the cortical bone at the site.
1.2.2 In cases of inferior stop injury where ligament tightening is not possible, the medial collateral ligament can be reinforced using the semitendinosus tendon.
(1) Static ligament reconstruction: use the semitendinosus tendon for reconstruction. The distal end of the semitendinosus tendon is dissected, the distal attachment is preserved, and the proximal end of the tendon is cut; a longitudinal bone groove is opened above the superior stop of the medial collateral ligament at the medial femoral condyle adductor node and the knee is flexed at 30°, and the knee is internally rotated in the position of the medial femoral condyle adductor node, a bone groove is opened above the superior stop of the medial collateral ligament and the proximal free end is fixed with a toothed screw or fixed with a riding suture.
(2) Powerful reinforcement of the medial collateral ligament: dissect the free semitendinosus tendon without cutting both ends to maintain its continuity. A transverse bony groove is opened above the superior stop of the medial collateral ligament at the medial femoral condyle adductor node, and the semitendinosus tendon is tractionally embedded and suspended in the groove. The advantage of this method is to maintain the integrity and continuity of the tendon with the muscle, which in turn allows the tendon to be tensed when the muscle contracts, thus enhancing the stability of the medial knee joint.
1.2.3 Postoperative treatment Postoperative cotton leg compression bandage, fixed with adjustable knee brace 20°～30°, 3-4 weeks to start knee gradually flexion and extension functional exercises and weight training, 6 weeks flexion angle over 90°, full weight bearing, 8 weeks flexion angle over 120° and gradually to normal; protective with knee brace for 3 months, strengthen muscle strength training, six months later can resume general sports.
2, lateral collateral ligament injury of the knee joint
The lateral collateral ligament is a circular cord about 5 cm long, located between the lateral epicondyle of the femur and the small head of the fibula, separated from the joint capsule by the N tendon and loose tissue, and not connected to the meniscus. The external artery and nerve of the inferior knee cross its deep surface. During knee extension, this ligament is tense and, together with the iliotibial bundle, restricts knee inversion and tibial rotation. It relaxes during knee flexion, allowing a small amount of internal and external rotation of the lower leg. If the knee joint is overly pronated, it can cause an avulsion or tear of the lateral collateral ligament. The lateral collateral ligament is the primary stabilizing structure against inversion stress during knee extension, and a complete rupture of this collateral ligament ligament will cause lateral instability of the knee. Therefore, a complete rupture of the lateral collateral ligament should be treated surgically.
2.1 Management of simple lateral collateral ligament rupture
(1) The middle part of the ligament can be sutured end to end by Bunnell’s method, and a tendon strip, 6-8 cm long, can be cut from the anterior edge of the end of the biceps femoris tendon and sutured at the proximal end. A silk suture can also be used to close both ends of the 8-way suture.
(2) The laceration of the fibula can be fixed to the bone with a thick silk thread according to the Bunnell method.
(3) Rupture at the upper stop should be rebuilt by in situ repair of the severed end using the bone drilling method.
2.2 Repair of compound ligament injury
(1) For tears of the lateral collateral ligament and the attachment of the femoral epicondyle of the N muscle, the proximal end of the lateral collateral ligament can be fixed to the original attachment with screws with tooth washers, while the N muscle is fixed there with silk sutures.
(2) The posterior lateral arcuate ligament and bean-fibular ligament complex is torn from the fibular tuberosity and sutured with silk sutures; the upper end of the tear is sutured to the periosteum on the deep side of the lateral head of the gastrocnemius; if the tear is in the middle, interrupted sutures are made and the lateral edge is advanced and sutured to the posterior edge of the lateral median joint capsule and the posterior edge of the lateral collateral ligament. Biceps femoris tendon, gastrocnemius tendon and iliotibial bundle can also be applied to strengthen the repair.
2.3 Postoperative management
After surgery, the cotton leg is compressively bandaged, the knee is flexed at 30°, the lower limb is fixed in a plaster brace before and after the long leg, and the knee is gradually flexed and extended in 3-4 weeks and can be replaced with an adjustable knee brace and gradually trained with weight, and the knee is flexed at an angle of over 90° with full weight at 6 weeks, and at an angle of over 120° and gradually to normal at 8 weeks; the knee brace is protected for 3 months, and the muscle training is strengthened, and the general movement can be resumed after 6 months. Sports.
3. Anterior cruciate ligament injury of the knee
3.1 Anterior cruciate ligament (ACL) of the knee
The ACL starts slightly medially in front of the tibial intercondylar spine and ends obliquely posteriorly at the posterior part of the lateral intercondylar aspect of the femoral epicondyle. The ACL is divided into the anterior internal, posterior external and intermediate bundles, with the anterior internal bundle tense during knee flexion and the posterior external bundle tense during knee extension, while the intermediate bundle remains in tension during knee flexion and extension.
The ACL is an important static and dynamic stabilizing structure that works with other ligaments to maintain the normal motion of the tibial joint. the main function of the ACL is to prevent the tibia from moving forward during knee flexion and to prevent the knee from hyperextending during knee extension; it also controls knee rotation and controls It also controls knee rotation, controls knee inversion at different knee flexion angles, participates in the final locking motion when extending the knee, and has a proprioceptive function. The normal ACL is generally loaded at 445 N and 500-1000 N during exercise, with an average fracture strength of 1730 N. Its tensile and tensile strength decreases with age. Different speed loading will cause different parts of the injury, fast loading mostly causes parenchymal fracture, slow loading is easy to induce stop avulsion injury.
3.2 Overview of ACL injury treatment
At present, regarding the treatment of acute ACL injury, especially the research on the biomechanical properties of the knee joint, with the progress of clinical basic research in recent years, the understanding of knee joint stability mechanism is more in-depth, and many scholars actively advocate early or even emergency repair or reconstruction of ACL rupture. The advantages of early surgery are clear injury site, good tissue repair conditions, the ability to repair early, and the ability to deal with combined injuries to restore stability to the knee joint early and prevent the occurrence of sequelae.
There are many methods of ACL reconstruction and clinical results vary. In the past, ACL repair and reconstruction were open surgeries, but with the development of minimally invasive arthroscopic surgery, the technique of arthroscopic ACL reconstruction has become very mature and widely used, and the traditional incisional reconstruction surgery has basically been replaced by arthroscopic reconstruction surgery. materials, and artificial materials. However, the most commonly used autologous material is the N-tendon. Currently, ACL single-bundle reconstruction has achieved good clinical results, but it always leaves the regret of poor improvement of knee rotation. Therefore, research is being conducted on ACL double-bundle reconstruction based on ACL single-bundle reconstruction. Although there are different observations of better clinical results than single-bundle reconstruction and no improvement, it also shows that as research continues, it is moving toward anatomical and biomechanical reconstruction.
3.3 Arthroscopic Reconstructive Surgery
A single-incision, fully intra-scopic technique for ACL reconstruction with built-in button fixation of the semitendinosus tendon and thin femoral tendon is used as an example.
3.3.1 Excision of the semitendinosus tendon and thin femoral tendon of the reconstructed graft A longitudinal incision is made at the medial aspect of the anterior tibial tuberosity near the attachment of the goose palm tendon, about 4-5 cm long, and the tendon is dissected layer by layer to the goose palm tendon, and the semitendinosus tendon and thin femoral tendon to be excised are dissected along its upper edge, and the full length of the tendon is excised subconsciously with a tendon extractor after adequate freeing. Attention should be paid to saphenous nerve and vascular injury when taking the material.
3.3.2 Preparation of the transplanted tendon The semitendinosus and thin femoral tendons are folded in two and overlapped into four strands, fixed on the graft preparation table for cut and sewing preparation, and then the folded end is connected to the two central holes of the built-in button (microperforated steel plate) with a 4-6 mm wide nylon braid (there are already prepared microperforated steel plates with tabs of different lengths such as 2.0, 2.5, 3.0, 3.5 The other free end is sutured with a No. 0 polyester braid and then prepared for use. A No. 0 absorbable suture is threaded through one side hole as a guide to lead the built-in button (microporous plate) outside the femoral cortex via the bone channel, and another 2-0 suture is threaded through the other side hole for final rotation of the built-in button (microporous plate) for fixation. The sutured tendon is pretensioned on the table with a force of 80 N for 5 minutes.
The femoral end of the semitendinosus tendon is inserted into the osteofemoral tract to a depth of at least 15 mm (20 to 25 mm is preferred). The desired depth of graft insertion plus the length of the connecting wire is the length of the entire femoral osseous tract, and the graft is prepared according to this requirement.
The diameter of the tibial and femoral bone tracts into which the graft is inserted is selected according to the thickness of the graft (generally 7-8 mm). After the tibial lateral canal is made, the femoral lateral canal is drilled at the base of the intercondylar fossa with an intrascopic drill, which is 6 mm deeper than the length of the intended insertion of the graft into the implant canal to provide a torsional radius for the built-in button. A 4.5 mm drill is then used to enter the top of the blind end of the lateral femoral tract via the tibial tract before continuing to drill forward until the tract penetrates the bone cortex and passes through the soft tissue, and the length of the femoral tract is accurately measured with a long, graduated probe.
3.3.4 Guided loading of the graft into the bone tract A marker is placed at 6 mm proximal to the desired site for insertion of the graft into the femoral bone tract, and then the graft is retracted using a 27 mm x 15 guide pin, which is passed through the tibial bone tract into the joint cavity and then into the femoral bone tract, and then the retraction wire is led through the soft tissue and skin, and then the graft is retracted into the bone tract, and when the marker point reaches the endoprosthesis of the femoral bone tract The 2-0 traction wire is pulled outward to rotate the built-in button, and then the graft is retracted 6 mm, so that the built-in button can be embedded parallel to the bone cortex on the external canal and play a fixed role. Finally, the distal end of the graft is tensioned at 30° of knee flexion and fixed according to the length of the graft.
3.3.5 Postoperative management and rehabilitation After the postoperative anesthesia period, the patient was encouraged to start muscle contraction exercises, and the drainage tube was removed within 48 to 72 hours. 3 to 5 days later, passive activities at 0° to 30° to 60° were started for functional rehabilitation of the knee. In the first week, no weight-bearing, in the second week, partial weight-bearing, in the third week, full weight-bearing and abduction, in the third week, the knee was flexed to 90°, in the fourth week, over 90°, in the fifth to sixth week, to 120°, in the eighth week, the knee should be flexed and extended to normal, and protected with a movable knee brace for three months, and in six months, the patient can participate in general sports activities. Athletes need one year to resume sports training and competition.
4. Posterior cruciate ligament injury of the knee
The posterior cruciate ligament (PCL) is located in the lateral posterior part of the articular surface of the medial femoral condyle and ends at the depression of the posterior lower slope of the tibial articular surface, about 0.5 cm below the tibial plateau. The PCL is an important structure to ensure the posterior stability of the knee joint. Currently, the incidence of PCL injury has increased significantly with the widespread development of sports and the increase of traffic injuries; further research on the biomechanical properties of the PCL has revealed that the PCL plays an important role in the stability of the knee joint, and a fracture of the PCL will lead to posterior instability and rotational instability, which will seriously affect the joint function, especially when combined with posterior lateral structural injury, which will result in severe posterior lateral instability.
4.1 In situ repair of PCL stop avulsion fracture
Repair of simple PCL tibial and femoral end avulsion fractures should be performed with in situ repair of the stop. For those with larger bone end avulsion fragments, the avulsion fragment should be rectified and the avulsion fracture block should be fixed with one to two compression screws (metal or absorbable screws). Usually avulsion fractures are more frequent at the lower stop of the tibial end, while avulsion fractures at the femoral end of the attachment are rare clinically. Currently, repair of PCL tibial and femoral end avulsion fractures can be accomplished well arthroscopically.
4.2 Arthroscopic PCL reconstruction
Arthroscopic reconstruction of the cruciate ligament after single tunneling of the femur can be performed with autologous bone-patellar tendon (middle 1/3)-bone quadriceps thin tendon and semitendinosus tendon, quadriceps tendon, etc. In addition, allograft tendons and artificial ligaments can be used for reconstruction. Reconstruction of the posterior cruciate ligament with double tunnels and double bundles of the femur has also been carried out with good clinical results, while reconstruction of the posterior cruciate ligament with double tunnels and double bundles of the tibia and femur is also under clinical study.
Arthroscopic reconstructive surgery: single-incision anterior approach with all-mirror technique (with the application of extrusion screws to fix the bone-patellar tendon (middle 1/3)-bone complex autograft to reconstruct the PCL as an example).
4.2.1 Tendon extraction A longitudinal incision, approximately 7-8 cm in length, was made layer by layer to the patellar tendon, and the middle 1/3 of the patellar tendon was excised from the bone-tendon-bone complex. The bone block on the tibial side was 2.5-3.0 cm long, 1.0 cm thick, and the width was the same as the width of the patellar tendon; the bone block on the patellar side was 1.5 cm long, 0.5-0.7 cm thick, and the width was the same as the patellar tendon. The bone blocks on both sides were trimmed and traction wires were drilled on the distal tendon end of the lateral patellar bone block, and sternal wires were drilled on the tibial bone block for fixation.
4.2.2 Arthroscopic manipulation
(1) The anteromedial and lateral approaches to the knee were operated arthroscopically to treat the combined injury; the PCL stump was treated with a planer and ArthroCare low-temperature plasma knife, and the medial intercondylar wall was cleaned to fully expose the PCL superior stop locator; the synovial compartment and connective tissue in the posterior compartment of the joint cavity were cleaned, and the synovial membrane and joint capsule below the posterior edge of the tibial plateau were separated to expose the inferior stop locator for accurate placement of the PCL lower stop locator.
(2) Then, using the PCL locator, the center point of the inferior PCL tract is positioned 1 to 1.5 cm below and slightly outside the posterior edge of the tibial plateau, and then the guide pin is drilled from the medial side of the tibial tuberosity from the inner inferior to the posterior superior obliquely through the locator, and then the inferior tibial tract on the tibial side is drilled through the guide pin with a hollow drill (diameter according to the width of the bone block of the graft).
(3) Using an upper stop locator, the femoral side of the medial femoral condyle is positioned slightly anteriorly superior to the center of the original PCL upper stop (at 10:30 of the medial condyle) at a distance of 8 mm from the cartilage margin, a guide pin is drilled through the locator, and then the femoral side of the superior osseous tract is created by drilling the intercondylar surface from the outside to the inside of the femur with a hollow drill through the guide pin.
(4) The bone tracts on both sides were appropriately widened and the bone-tendon-bone complex (patellar bone block in front) was introduced into the joint cavity from the lateral tibial bone tract and then into the lateral femoral bone tract using traction screws for the upper bone block and then the reconstructed ligament was tensioned in the 70° flexed knee position, while the lower bone block could be fixed with traction screws as appropriate depending on its location (the position of the lower bone block in the lateral tibial bone tract is suitable for fixation with traction screws) The lower bone block can be fixed with a squeeze screw (if the position of the lower bone block in the lateral tibial canal is not suitable for fixation with a squeeze screw) or with a posterior fixation method of a portal nail and wire.
(5) For combined ACL rupture, the bone-tendon-bone complex of the contralateral knee or the semitendinosus tendon and thin femoral tendon of the ipsilateral knee (reflexed into 4 strands) are taken and the ACL is reconstructed using a total intra-scopic technique.
(6) The joint cavity and wound were repeatedly flushed, and a negative pressure drainage tube was placed in the joint cavity and led out through the entrance of the perfusion tube above the inner; another negative pressure drainage tube was placed under the skin at the tendon extraction site and led out through the skin poke for fixation; intermittent sutures were placed to close the patellar tendon defect and the surgical incision. After surgery, the cotton leg was wrapped with pressure, and the knee joint was fixed with an adjustable knee brace in the straight position.
4.2.3 Postoperative management After the anesthesia period, the patient was encouraged to perform quadriceps contraction exercises in the knee brace, and to start quadriceps isometric contraction, straight leg raising and passive mobility exercises as early as possible. 48 hours later, the drainage was removed, and the patient was allowed to go down with the abductor on the second to third day; 1 week later, the knee started functional exercises in the range of 0° to 60° with partial weight bearing, and gradually to 2 weeks with full weight bearing and abandonment of the abductor; 4 weeks with knee flexion The knee should be over 90° at 4 weeks, flexion and extension should be in the range of 0° to 120° at 6 weeks, and flexion and extension activities should be at or near normal at 8 weeks; the knee brace should be used for 3 months for protection, and after removing the brace, daily activities should be gradually resumed, walking and squatting should be practiced; stairs should be allowed at 5 months, trotting should be started at 6 months, and general sports activities should be resumed at 9 months; athletes need 1 year to resume sports training and competition.
4.3 Repair surgery for PCL rupture combined with posterior lateral structural injury
PCL rupture combined with posterior posterolateral structures (lateral collateral ligament, slapping tendon, and slapping fibular ligament, the first two being the main posterior lateral stabilizing structures) is a more serious joint injury and will lead to severe posterior lateral instability of the knee if left untreated. Therefore, PCL reconstruction should be performed along with the repair and reconstruction of the posterior posterolateral structures.