Knee stuff
Meniscectomy
A meniscectomy is the surgical resection or removal of the meniscus.
The microfracture procedure
A surgeon visually assesses the defect and any unstable cartilage is removed from the exposed bone. The surrounding rim of remaining articular cartilage is also checked for loose or marginally attached cartilage. This loose cartilage is also removed so that there is a stable edge of cartilage surrounding the defect. The process of thoroughly cleaning and preparing the defect is essential for optimum results. Multiple holes, or microfractures, are then made in the exposed bone about 3 to 4mm apart. Bone marrow cells and blood from the holes combine to form a "super clot" that completely covers the damaged area. This marrow-rich clot is the basis for the new tissue formation. The microfracture technique produces a rough bone surface that the clot adheres to more easily. This clot eventually matures into firm repair tissue ( fibrocartilage) that becomes smooth and durable. This maturing process is gradual, and it usually takes four to six months after the procedure for the patient to experience improvement in the pain and function of the knee.
2 types of meniscus tears
Acute tears are from the excessive force applied to a normal knee and meniscus. Typically, the mechanism of injury involves a twisting, pivoting, or explosive maneuver followed by pain and gradual onset of swelling. degenerative tear, which results from repetitive normal forces acting upon a worn-down meniscus. Degenerative tears generally have a complex tear pattern. symptoms-pain, clicking or catching, and a loss of confidence in the knee, though some tears may be asymptomatic1
All-Inside Technique
All-inside meniscal repair devices and techniques have rapidly evolved, resulting in increased ease of use and reduced surgical times and risk to the neurovascular structures8. Indicated for middle to posterior third meniscal repairs, this technique does not require additional incisions. Advantages: Designed to be a safer procedure without a posterior incision near neurovascular structures Uses standard portals, though accessory portals may be required for access No trained assistant needed Address a majority of tear types Faster & easier Repair strength is comparable to inside-out techniques Can address both side of tear with vertical mattress stitch Disadvantages: Higher cost than inside -out or outside-in techniques Potential for implant failure
What are the three FAST-FIX FLEX Meniscal Repair System depth penetration limiter needle exposure positions?
12mm, 16mm, 20mm
A meniscus root tear can be defined as either an avulsion of the meniscal root from its attachment point or a radial root tear within _____ of the root attachment.
1cm
peak contact pressure increased by approximately ____% after a medial meniscectomy.
235%
How far apart should microfracture 'holes' be placed in a microfracture procedure?
3-4mm
Evidence shows that 57% of patients with a partial meniscectomy had development or progression of OA, compared with ______% of meniscal repair patients.
32%
The bend tool enables distal needle modification of the curved FAST-FIX FLEX device up to _________.
35°
Jaureguito et al. reported that 85% of the patients could resume their pre-injury level activities at 2 years after partial meniscectomy. However, at 8 years after surgery, only ____% of these patients could maintain their pre-injury activity level.
48%
In a clinical paper by Stein et al. comparing long term outcomes after arthroscopic meniscal repair vs. arthroscopic partial meniscectomy for traumatic meniscal tears, pre-injury activity level function was obtained in 96.2% after repair vs. ___ % after meniscectomy.
50%
Load Transmission:
50% of the load on the knee joint is transmitted through the meniscus in extension 85% of the load of the knee is transmitted at 90º flexion11
Evidence shows that _____% of patients with a partial meniscectomy had development or progression of OA, compared with ______% of meniscal repair patients.
57%, 32%
Evidence demonstrates that the relative risk of long-term degenerative change is ______higher in patients treated with partial meniscectomy compared with those treated with meniscal repair.
78%
The bend tool enables FAST-FIX FLEX Meniscal Repair System proximal shaft modification up to _________.
80°
Long Term Outcome After Arthroscopic Meniscal Repair vs. Arthroscopic Partial Meniscectomy for Traumatic Meniscal Tears 7 (Stein et al. The American Journal of Sports Medicine, 2010)
81 patients with meniscus shaped-preserving surgery after a traumatic medial meniscal tear Repair: n=42, Meniscectomy: n=39 Clinical assessment (Tegner and Lysolm scores), radiologic assessment (Fairbank score) compared with patients uninjured knee Follow up: Midterm (3.4 years; n=35), long term (8.8 years; n=46) No osteoarthritis (OA) progress in 80.8% patients after repair compared with 40.0% after meniscectomy A significant benefit for 'young' group (< 30 yrs) Pre-injury activity level function obtained in 96.2% after repair vs. 50% after meniscectomy Athletes (recreational sport 5 or more times per week) showed a significantly reduced loss of sports activity after repair
Evidence shows that meniscal tear types which have not traditionally been identified as targets for meniscal repair report a clinically successful outcome for between___________ of patients.
89% to 99%
The FAST-FIX FLEX Meniscal Repair System is designed to enable the surgeon to increase meniscus repair in which zones of the meniscus? ( Choose 2)
Anterior Middle
Ligaments of the knee
Anterior cruciate ligament (ACL) Posterior cruciate ligament (PCL) Transverse ligament Meniscofemoral ligaments Meniscotibial ligaments Patellar ligament Medial collateral ligament (MCL) Oblique popliteal ligament Arcuate popliteal ligament
The anterior cruciate ligament (ACL) has two bands or bundles. What are they called?
Anteromedial band Posterolateral band
Partial-thickness tear:
Any tear which extends through only a portion of the vertical depth of the meniscus.
Full-thickness tear:
Any tear which extends through the entire vertical depth of the meniscus
Some surgeons will perform partial meniscectomy over a repair because short-term results of partial meniscectomy are good. What are two factors that may sway this decision?
Arthroscopic partial meniscectomy facilitates rapid rehabilitation Arthroscopic partial meniscectomy facilitates early functional recovery
Injuries commonly seen in combination with MCL injuries
Bone bruises ACL tears Lateral collateral ligament (LCL) tears Medial meniscus tears Lateral meniscus tears Posterior collateral ligament (PCL) tears
static stabilizers
Bony configuration of joints, fibrocartilages, and ligaments that contribute to core stability
Vertical tears that displace are called:
Bucket handle tears
medial meniscus
C-shaped (cresent), 20-30% vascular, less mobile than the lateral meniscus
Hybrid Repairs
Combination of two or more techniques Not all meniscal tears can be addressed with one repair technique. It may be necessary to implement more than one solution for complex situations such as large tears. A surgeon may need intraoperative flexibility to address pathology appropriately.
Shock Absorption:
Complete loss of a meniscus increases the contact pressures between the femur and the tibia by over 200%, causing increased wear within the knee
Ligament
Connects bone to bone
Tendon
Connects muscle to bone
Your surgeon decide that more curvature is required to access a meniscal repair site. According to the surgical technique, what bending tip can you share for an anterior tear?
Consider bending the needle and the shaft
What is the function of the anterior cruciate ligament?
Controls anterior tibial translation and tibial rotation
The FAST-FIX FLEX Meniscal Repair System is available in which of the following needle configurations?
Curved Reverse Curved
Horizontal tears
Horizontal tears that run parallel to the tibial plateau and divide the meniscus into superior and inferior layers which are called lamina or leaflets. More complicated than other tears
There are three different types of cartilage:
Hyaline Cartilage Elastic cartilage Fibrocartilage
Transtibial Technique
In the transtibial tunnel technique the ACL femoral tunnel is drilled through a tibial tunnel positioned in the posterior half of the native ACL tibial attachment site. Surgeons tend to use this technique as it is relatively easy, quick and reproducible. Femoral tunnel preparation is achieved with the use of a femoral 'over-the-top' guide (endofemoral aimer). This technique consistently produces long, intact and minimally angulated tunnels. Issues: instability
There are three major meniscal repair techniques:
Inside-Out Technique Outside-In Technique All-Inside Technique
Three treatment options are currently employed by surgeons for the reconstruction of medial structures.
Isolated medial collateral ligament (sMCL) reconstruction Non-anatomic double bundle posteromedial corner reconstruction (Reconstruction of the sMCL and POL using a single femoral tunnel) Anatomic posteromedial corner reconstruction. (POL, posterior oblique ligament; sMCL, superficial medial collateral ligament.)
Does patient age impact on success rates following meniscal surgery?
It is generally accepted that younger patients are better candidates for meniscal repair as they are thought to have a greater capacity for healing.29 A review was conducted to evaluate the current evidence on procedural success in older patients versus younger patients undergoing meniscal repair surgery. The finding from a systematic literature review challenges the accepted wisdom that meniscal repair is more successful in younger patients,29 and shows that age should not be the sole determining factor in the decision as to whether to repair or resect the meniscus.
Post meniscectomy effects may include which three of the following?
Loss of joint lubrication Loss of shock absorbance with altered bone loading Cartilage regeneration Peak pressure and stress concentration on cartilage decreased stability
Which tear type starts at the apex and cut across the circumferential fibers of the meniscus?
Radial
What has improved understanding of meniscal pathophysiology and enhanced arthroscopic repair methods done for meniscal repair indications?
Re-evaluated the clinical success of repairing horizontal, radial, root and ramp lesions.
The FAST-FIX FLEX Meniscal Repair System offers surgeons the ability to bend the needle and shaft. This means surgeons can access all meniscus body zones empowering surgeons to ____________ .
Reach more and repair more tears
two ways to treat meniscus tears arthroscopically:
Resection involves removing the damaged or torn portion of the meniscus and leaving behind a smooth and stable rim. This treatment has very little downtime with patients bearing full weight immediately following surgery and returning to sport participation in as little as 4 weeks. However, the downside is that some meniscus tissue is lost and there is a higher incidence of arthritis in the future. In fact, it has been shown that after partial meniscectomy peak local contact stresses can increase by approximately 65%4. 2 Meniscus repair involves placing anchors and/or sutures to bridge the tear in an effort to get the body to heal the tissue. This treatment requires post-operative rehabilitation and may lead to a slower return to sports participation. If the meniscal tear heals successfully, the overall risk of arthritic changes may be reduced. not all candidates can be repaired- Tears such as degenerative tears and some radial tears may not be possible to repair. For these, a partial meniscectomy may be the only option
All four hamstring tendons
Sartorius, semimembranosis, semitendinosis and gracilis
chondrocytes
The only cell type found in cartilage. are embedded within a dense extracellular matrix (ECM) comprised of tissue fluid and macromolecules such as collagen, proteoglycans, glycoproteins, and non-collagenous proteins.
advantages of a partial meniscectomy
The peripheral rim of the meniscus that is responsible for the biomechanical function of the knee can be preserved. The short-term results of partial meniscectomy are good. Arthroscopic partial removal facilitates rapid rehabilitation and early functional recovery with low morbidity. For patients who want short term relief, this is often the chosen treatment. It is a quick and relatively easy procedure, with a short recovery period. 90% of the patients obtained good or excellent results and 85% of the patients could resume their pre-injury level activities at 2 years after partial meniscectomy. However, only 62% of the patients exhibited good or excellent results and only 48% could maintain their pre-injury activity level at 8 years after surgery.
Does Arthroscopic Partial Meniscectomy Result in Knee Osteoarthritis? A Systematic Review With a Minimum of 8 Years Follow up.6 (Lubowitz, Petty . Arthroscopy, 2011)
The purpose of this study is to evaluate the long term results of arthroscopic partial meniscectomy with regards to knee osteoarthritis. Systematic review Included Levels I to IV evidence studies reporting either radiographic or clinical osteoarthritis outcome measures with a minimum of 8 years' follow-up after partial arthroscopic meniscectomy Five studies comparing normal contralateral knee as radiographic control. None included a clinical control group Follow up 8 to 16 yrs All studies showed significant radiographic signs of OA compared to contralateral control knee after 8 to 16 years Clinical symptoms of osteoarthritis were not observed. Furthermore, clinical outcomes did not correlate with radiographic findings. Conclusion: Radiographic signs of osteoarthritis are significant at 8 to 16 years' follow-up after knee arthroscopic partial meniscectomy, but clinical symptoms of knee arthritis are not significant.
Does the long-term risk of degenerative change differ following meniscal repair and partial meniscectomy?
The well-established link between total meniscectomy and degenerative joint changes1 led to the widespread adoption of partial over complete resection. In spite of more favorable results, even partial removal of the meniscus increases the risk of long-term degenerative changes. This has made the use of meniscal repair, where appropriate, the treatment of choice for symptomatic tears. The results of this review demonstrate that the relative risk of long-term degenerative change is 78% higher in patients treated with partial meniscectomy compared with those treated with meniscal repair.
The inside-out technique can offer advantages
This technique has the versatility to address most tear patterns in the middle to posterior third of the meniscus. A surgeon delivers sutures with small needle diameters, and with proven long-term results5, it has been is considered the 'gold-standard' technique for meniscus repair. The inside-out meniscus repair technique requires an accessory posteromedial or posterolateral incision. This exposure allows protection of the neurovascular structures during suture retrieval and knot tying. Advantages: Easy to access the meniscal surface Ability to insert horizontal & vertical mattress stitches on both surfaces of the meniscus Low risk of damage to chondral surfaces Inexpensive Disadvantages: Posteromedial or posterolateral incision Higher risk of neurovascular damage Requires a trained assistant
True or False: Vascularisation in the meniscus is of high relevance in sports medicine. This may determine the possibility and success of meniscal repair.
True
Valgus Stress Test
application of a medial force to the lateral aspect of a joint in an attempt to create a gap in the medial joint line, thereby testing the stability of the medial aspect of the joint.
Complete longitudinal tears where the inner fragment can displaced into the notch and often become trapped are referred to as_______________ tears.
bucket-handle
Mosaicplasty
cartilage ('chondral') lesions and bone and cartilage ('osteochondral') lesions are repaired by harvesting and transplanting cylindrical plugs of bone and cartilage. In the knee, these plugs are taken from less weight-bearing areas, termed 'donor sites', and inserted into drilled tunnels in the prepared cartilage defect. The transplanted hyaline cartilage is capable of surviving and produces a fibrocartilage layer11. This layer may be more durable surface than the fibrous repair tissue that would have formed if the defective cartilage had been left to heal on its own. Repair of the donor site occurs via natural healing processes. The tunnels become filled with cancellous bone and the surface is covered with fibrocartilage built by marrow-derived cells. Implanting the grafts in a mosaic-like fashion allows the effective management of small and medium-sized localised, or 'focal', defects (10-25mm2). An Osteochondral Allograft Transplantation (OAT) procedure may be better indicated for larger lesions. This is because a larger lesion requires more transplants from the donor site which increases the risk of donor site morbidity, pain, tissue deterioration, and/or a decline in knee function.8,9
elastic cartilage
cartilage with abundant elastic fibers; more flexible than hyaline cartilage. ex: your ear
Types of meniscectomy surgeries
complete meniscectomy where the meniscus and the meniscal rim are removed partial meniscectomy where only a section of the meniscus is removed. This may vary from a minor trimming of a frayed edge to anything short of removing the meniscal rim Historically, partial or total meniscectomy was a common procedure performed for meniscus tear symptoms. However, it has been reported that meniscectomy can have deleterious effects on the knee
Not all meniscal tears are symptomatic but those that go untreated can progress to
flap and complex tears
four grade stages of cartilage lesions
grade 0- normal stuff cartilage with smooth appearance grade 1- cartilage with softening and swelling grade 2- partial thickness defect with fissures on the surface that do not reach subchondral bone or exceed 1.5 cm in diameter <50% cartilage depth grade 3- fissuring to subchondral bone in area with diameter more than 1.5 cm grade 4- full thickness defect. exposed subchondral bone
Outerbridge Cartilage Lesion Classification
is a macroscopic classification of articular cartilage. It uses both appearance and size of the lesion to assign a four-grade staging
FAST-FIX FLEX Meniscal Repair System
less disruption to the meniscus, FAST-FIX◊ FLEX provides enhanced* accessibility 8-11through guided needle + shaft modification on a clinically proven and reliable platform Available in the following configurations: + Curved needle + Reverse Curved FAST-FIX FLEX provides access to the mid-body and, with the ability to bend the needle and shaft, surgeons can also access the anterior third of the meniscus, both have been shown to account for 43.1% of tears in stable adult knees 8,9,11 Curved device: FAST-FIX◊ FLEX Curved device has a manufactured curvature of 24° Distal needle modification up to 35° Proximal shaft modification up to 80° Reverse curved device: + FAST-FIX FLEX Reverse Curved device has a manufactured curvature of -12° + Distal needle modification up to -22° + Proximal shaft modification up to -80°
Surgery in the posterior knee region can be challenging because of the presence of _____________ structures
neurovascular
meniscus root tear
root avulsion (detachment from the tibial plateau) or a tear that is within a centimeter of the root attachment. Posterior root tears are more common than anterior tears
The three hamstring tendons that insert at the pes anserinus are:
sartorius, gracilis and semitendinosis
Fibrocartilage
strongest and most rigid, more type 1 collagen which is tougher than type II. makes up tendons, ligaments, and menisci. also appears in other high stress areas
Longitudinal/Vertical tears
tears that are perpendicular to the surfaces of the meniscus. Vertical tears divide the meniscus along its circumferential fibers into central and peripheral components. The meniscus has a displaceable inner fragment and a stable outer rim. The longer the tear, the more unstable it is. Oblique tear
meniscus it can be divided into three roughly equal-sized segments:
the anterior segment or anterior horn, the middle segment ( or 'body' of the meniscus), and the posterior segment or posterior horn.
three muscles in the posterior compartment of the thigh
the biceps femoris and two synergistic muscles (the semitendinosus and semimembranosus). These muscles are sometimes termed the hamstring group.
tibiofemoral joint
the point where the tibia meets with the femur
4 bones of the knee
tibia, fibula, femur, patella
neurovascular structures in the posterior knee region
tibial nerve, popliteal artery and vein, and common peroneal nerve.
Radial tears
type of meniscal tear; tears from the edge of the cartilage inwards; tears from the inside to outside. always start at the apex of the meniscus and move peripherally like the radius of a circle. Radial tears divide the meniscus in to anterior and posterior portions more common in lateral meniscus Tears further than 1cm from the root are generally classified as radial tears
Current Cartilage Treatment Options
Debridement can be considered as an initial treatment for defects <2 cm2 in less demanding patients. Debridement of small defects can provide symptomatic relief in terms of pain, catching and locking, the response to treatment of these defects as well as their natural history remains unpredictable. Microfracture : generally considered a good option for smaller (<2 to 3 cm2) defects7. Microdrilling Light Abrasion (looks like holes) (swiss cheesey) Grafting involves the harvesting of healthy cartilage and moving it to the defect site. This can be done using an autograft, from the patient or an allograft, from a donor. Osteochondral Autograft - Mosaicplasty Osteochondral Allograft Transplantation (OAT)- For larger lesions where donor site morbidity may lead to pain, tissue deterioration and a decline in knee function 8,9 Biphasic implants, morselized/micronized cartilage Autologous Chondrocyte Implantation (ACI) is a two-step procedure that involves first harvesting articular cartilage to culture them in a lab. In the second step of the procedure, these harvested cells are implanted in the defect site and held in the site by a patch. Membrane Autologous Chondrocyte Implantation (MACI) is FDA approved for use in patients 18-55 years old and in the knee joint. It is still a two-step procedure and requires the surgeon to template, size, and shape, the patch to fit the defect. Defect size is currently used as one of the primary indicators for treatment selection. Although no single size threshold can be identified, defects greater than 2 to 3 cm2 can be considered more suited for transplantation procedures, while microfracture would be more suitable for smaller defects.
What is currently used as one of the primary indicators for cartilage treatment selection?
Defect size
Cartilage
Dense connective tissue forming a firm, compact matrix Capable of withstanding considerable pressure and/or tension The cartilage covering the articulating surfaces of bones, it is known as HYALINE CARTILAGE
Proprioception
Even a partial absence of menisci causes a deterioration of proprioceptive functions of the knee
Meniscal Repair: The Evidence It is generally accepted that younger patients are better candidates for meniscal repair as they are thought to have a greater capacity for healing. What does this evidence review show?
Evidence shows that age should not be the sole determining factor in the decision as to whether to repair or resect the meniscus.
Fish mouth tears
Extend completely to the medial edge of the central zone, type of horizontal tear, looks like fish mouth
Differentiators from FAST-FIX 360 Meniscal Repair System
FAST-FIX◊ FLEX differs from the FAST-FIX 360 Meniscal Repair system in the following ways: Implant alignment Implant deployment Needle Exposure Device introduction into the joint space Bend tools -color coded to needle curvature ( curved/reverse curved) NOVOCUT◊ Suture Manager
Meniscus functions
Functions of the meniscus: Shock Absorption Load Transmission Proprioception Joint Stability Joint Lubrication
Medial Collateral Injuries
Grade I | mild injury, with minimally torn fibers and no loss of MCL integrity Grade II | moderate injury, with an incomplete tear and increased laxity of the MCL Grade III | severe injury, with a complete tear and gross laxity of the MCL Grade II is lax in 30° of knee flexion and solid in full extension Grade III is lax in 30° and in full extension
Outside-In Technique
Meniscal tears involving the anterior horn are increasingly recognized as an important pathology. Due to the location of anterior horn tears and the technical difficulty in accessing this location arthroscopically, an outside-in repair technique is the indicated technique for treatment of these lesions. This technique employs the passage of single sutures from the outside of the knee, through small incisions into the joint capsule,through the superior and inferior surfaces of the meniscus. These are then retrieved and tied in a knot, and finally ligated over the capsule Advantages: Requires only a small stab skin incision to tie sutures over the capsule. Simple and low-cost instrumentation. Meniscal Repair option to repair difficult to reach anterior horn tears of meniscus. All suture/no implant, and stitches can be placed close together. Disadvantages: Precise needle exit point can be more difficult to control1. Challenging to accomplish a true vertical mattress sutures. Learning curve if not commonly performed. The MENISCAL MENDER II Repair System is an 'outside-in' suture technique that is designed for repairing the meniscus under direct arthroscopic monitoring. The MENSICAL MENDER II Repair System utilizes curved and straight needles and a patented suture-capture loop. Depending on the patient's anatomy, the surgeon may use a combination of curved or straight needles in order to best access the tear. These components allow the surgeon to use the outside-in approach, which may help minimize the risk of damage to neurovascular structures during a meniscal repair. bullet Indicated for the repair of anterior horn and middle third tears bullet Convenient, low cost disposable kit bullet Multiple technique options using braided or monofilament suture (not included in kit)
hyaline cartilage
Most common type of cartilage; it is found on the ends of long bones, ribs, and nose, mostly type II collagen fibers
Dynamic stabilizers
Muscles that actively contribute to core stability
Most common mechanism of ACL injury?
Non-contact, valgus strain on knee-
lateral meniscus
O shaped, 10-25% vascular
Meniscal injuries occur predominately from two main causes:
One cause is that seen in traumatic knee injuries where normal healthy meniscal tissue is subjected to damage when the knee joint is bent and abnormally twisted (often seen in athletes). The other cause is from degenerative processes that occur as the meniscus becomes more brittle and structurally weak with advancing age
What is the function of the grey lever on the NOVOCUT device?
Opens up the rotating mandrel to load suture limb
In 1948, Fairbank described radiographic changes of the knee joint in patients after meniscectomy. These included which three of the following?
Osteophyte formation Squaring of the femoral condyle Joint space narrowing
Outside-In Technique
Outside-in Retrograde drilling creates an anatomic femoral tunnel and socket during ACL reconstruction. Anatomic placement of a guide wire is achieved using the ACUFEX◊ PINPOINT Pivoting Guide. Antegrade and Retrograde drilling of the femoral tunnel and socket is then enabled by the ACUFEX TRUNAV Retrograde Drill. Advantages: There may be reduced risk of damage to the articular cartilage of the medial femoral condyle. Deep flexion is not required. Ability to drill tunnels independently
The trochlea is also called the
Patellofemoral groove
Which is larger- acl or pcl
Pcl
Post-meniscectomy effects
Peak pressure and stress concentration on cartilage Loss of shock absorbance with altered bone loading Loss of joint lubrication Cartilage delamination Increased instability
Locations of injuries to the meniscus are described in terms of both segment and zone. What are the three zones that are described?
Peripheral Central Mid-substance
Vertical tears are _________ to the surfaces of the meniscus.
Perpendicular
Which of the following are three goals of meniscal repair?
Preserve and optimise function Prevent future degeneration Stabilize torn or damaged tissue
Goals of meniscal repair
Preserve healthy meniscus tissue Alleviate pain Stabilize torn or damaged tissue Preserve and optimise function Prevent future degeneration
Goals of meniscal repair include:
Preserve healthy meniscus tissue bullet Alleviate pain bullet Stabilize torn or damaged tissue bullet Preserve and optimise knee function bullet Prevent future degeneration of cartilage
Which tendon may be used as a graft in ACL reconstruction?
Semitendinosis
The tibia
Shin bone, The entire proximal surface of the tibia is commonly referred to as the tibial plateau Two concave tibial condyles correspond to the convex femoral condyles and cover most of the surface of the tibia The lateral tibial condyle is flatter, shorter from anterior to posterior, and more rounded The medial tibial condyle is more concave, longer from anterior to posterior, and more oval The central aspects of both tibial condyles are marked by slight elevations due to a rise in the underlying bone commonly known as the tibial spines The exposed bone surfaces between the tibial condyles are called the anterior intercondylar area and the posterior intercondylar area
Functions of the meniscus:
Shock Absorption: Complete loss of a meniscus increases the contact pressures between the femur and the tibia by over 200%, causing increased wear within the knee. Load Transmission: 50% of the load on the knee joint is transmitted through the meniscus in extension 85% of the load of the knee is transmitted at 90º flexion11 Proprioception: Even a partial absence of menisci causes a deterioration of proprioceptive functions of the knee12 Joint Stability: The meniscus increases joint congruity. Following an ACL tear, the posterior horn of the medial meniscus helps to limit further anterior-posterior (AP) translation of the tibia. It is a secondary restraint. Joint Lubrication: The meniscus assists in lubrication and joint nutrition
All-Inside Technique
Some features of this technique include closed-socket tunnels, dual (femoral and tibial) cortical suspensory graft fixation, decreased bone removal, and smaller skin incisions.16 The all-inside ACL technique typically utilises a tripled or quadrupled semitendinosus tendon autograft.19 In contrast, other standard ACL techniques typically utilize a bone-tendon-bone (BTB) or semitendinosus-gracilis (S-G) tendon autograft. A 'closed femoral/tibial socket' can be thought of as a champagne glass where the stem is the tunnel (big enough for a button to pass through) and the socket is the bowl (which is sized to fit the graft diameter). Since closed femoral and tibial sockets are drilled rather than full tunnels, a decreased graft length is necessary for the all-inside ACL technique.A major difference related to the all-inside technique is the drilling of closed sockets (instead of the full tibial tunnels typically seen in standard ACL technique).Studies using X-ray and CT imaging to evaluate the sockets drilled with an all-inside ACL technique have reported less socket expansion and preserved bone stock compared to full tunnels seen in standard ACL techniques.23,24. Further, the clinical study revealed decreased pain scores with the closed-sockets of the all-inside ACL technique compared to the full tunnels of a standard ACL technique. The use of retrograde reamers allows surgeons to avoid the need for knee hyperflexion and may ease the learning curve.26 Retroreamers like the ACUFEX◊ TRUNAV Retrograde Drill also provide the ability to drill independent tunnels, which can be advantageous during a revision ACL reconstruction or in a skeletally immature patient when looking to avoid the previous tunnels or growth plates respectively.In all-inside technique, a single hamstring tendon harvest may provide sufficient length to serve as the autograft when tripled or quadrupled
Hybrid repairs
Some tears require more than one technique and can be addressed with a combination of techniques
Meniscal Tears: The effect of Meniscectomy and of Repair on Intraarticular contact areas and stress in the human knee4 (Baratz, Fu et al American Journal of Sports Medicine,1986)
Study examines the biomechanical consequences of operative treatment of bucket handle and peripheral meniscal tears Contact area and intraarticular pressures measured Peak local contact stresses ( PLCS) measured at the point of contact between the femoral condyle and the tibial plateau After partial meniscectomy: Peak local contact stresses ( PLCS) increased average 67% After total meniscectomy: PLCS increased by average 236% Contact area decreased by 10% and 75% after partial and complete meniscectomy Concluded that contact stresses increased in proportion to the amount of meniscus removed and the degree to which the hoop tension of the meniscus is disrupted
What is the name of the cartilage zone in which the chondrocytes are small, immature and flattened, and collagen type II fibrils are arranged parallel to the surface?
Superficial Zone
Which of the following describes the FAST-FIX FLEX Meniscal Repair System alignment of implants?
T1 and T2 lie in a same plane inside the 17 gauge needle.
factors that should be considered when considering meniscal repair as a surgical option
Tear location, type and pattern Is the tear in the red-red, red-white or white-white zone? Is the tear radial, longitudinal, or bucket handle, for example? Can the meniscal tissue hold a stitch? Size and appearance of tear Acute vs. chronic tear Stability of the knee and concomitant injuries Are the knee ligaments intact or do they need to be repaired? ACL reconstruction has a beneficial impact on meniscal tear success Patient considerations Age and activity level Overall joint health Post-operative rehabilitation protocol Is the patient willing and able to comply with a post-operative rehabilitation regime?
The following factors should be considered when considering meniscal repair as a surgical option:
Tear location,type and pattern Is the tear in the red-red, red-white or white-white zone? Is the tear acute or chronic? Is the tear radial, longitudinal, or bucket handle, for example? Can the meniscal tissue hold a stitch? bullet Size and appearance of tear bullet Stability of the knee and concomitant injuries Are the knee ligaments intact or do they need to be repaired? ACL reconstruction has a beneficial impact on meniscal tear success bullet Patient considerations Age and activity level Overall joint health bullet Post-operative rehabilitation protocol Is the patient willing and able to comply with a post-operative rehabilitation regime?
The meniscus can also be divided into three roughly concentric zones.
The innermost is the central zone. Next to it is the mid-substance. The outermost concentricity is the peripheral zone. The junction between the meniscus and the capsule is the meniscocapsular junction.
Medial Portal Technique
The anteromedial portal technique is an ACL reconstruction technique in which the ACL femoral tunnel is drilled through an anteromedial or accessory anteromedial portal allows consistent anatomical ACL tunnel placement. The anterolateral (AL) portal—used as a viewing portal to perform diagnostic arthroscopy and meniscal surgery. The anteromedial (AM) portal—used as both a working and viewing portal. The Accessory Anteromedial (AAM) portal—used as a working portal to insert instrumentation into the notch and for drilling the ACL femoral tunnel. In the medial portal technique, the knee must be flexed to 120° or more when a rigid guide pin and drill bit are used to drill the ACL femoral tunnel. Hyperflexion is necessary to avoid having the femoral guide pin exit the lateral soft tissues too posteriorly. The peroneal nerve is at risk when the femoral guide pin exits the lateral soft tissues in a too posterior position. This tends to create shorter tunnels compared to those created by a transtibial technique.
Circumferential Compression Stitch Technique
The circumferential compression stitch is the only meniscus repair technique that treats the femoral and tibial sides of a tear simultaneously, enabling the repair of meniscal tears that may previously not repairable.This includes radial, horizontal cleavage and complex tears. This technique allows surgeons to arthroscopically place circumferential sutures around meniscus tears to provide uniform, anatomic compression of the tear edges through an all-inside technique
Why do we focus on the hamstrings?
The insertion on the anteromedial aspect of the tibial tubercle of the sartorius, gracilis and semitendinosis is known as the pes anserinus. To the untrained eye, these tendons lie in such close proximity to each other that they appear to be one tendon. Learning to identify and even separate them is crucial to an arthroscopic surgeon because the gracilis and semitendinosus tendons are frequently harvested as soft-tissue grafts for ACL and other ligament reconstructions.
Knee Joints
The knee comprises three joints: Tibiofemoral Joint (Articulation between the tibia and femur) Patellofemoral Joint (Articulation between patella and femur) Tibiofibular Joint (Articulation between tibia and fibula)
Meniscus
The menisci are fibrocartilages that rest between the articular surfaces of the femoral and tibial condyles, conforming closely to the surfaces of the tibial condyles to which they are attached. The lateral meniscus is more an 'O' shape, while the medial meniscus is a 'C' shape ( semilunar) The menisci occupy 60% of the contact area between the femoral and tibial cartilage surfaces and bear 40-50% of the load across the knee joint in extension and 85% of the compressive load in flexion1. Functionally, the menisci serve as shock absorbers for the knee, helping to protect the articulating cartilage-covered condyles, while at the same time aiding in stabilizing the joint. The principal intra-articular attachments of the menisci, those at their "ends," are often referred to as the horns of the menisci.In addition to these central attachments, each meniscus is attached at the periphery along its circumference to the tibia by coronary ligaments or capsular ligaments. These ligaments stabilize the meniscus2. The menisci consist of approximately 75% type I collagen9.
Joint Lubrication
The meniscus assists in lubrication and joint nutrition
Joint Stability
The meniscus increases joint congruity. Following an ACL tear, the posterior horn of the medial meniscus helps to limit further anterior-posterior (AP) translation of the tibia. It is a secondary restraint.
Tibiofemoral Contact Mechanics after Serial Meniscectomies in the Human Cadaveric Knee (Lee, Cole et al American Journal of Sports Medicine,2006)8
Twelve fresh-frozen human cadaveric knees, each underwent 15 separate testing conditions Intact, 50% radial width, 75% radial width, segmental, and total meniscectomy) at 3 flexion angles Tekscan sensors were used to measure total force and medial force, contact area, mean contact stress, and peak contact stress Conclusions: The meniscus is a crucial load-bearing structure, optimizing contact area and minimizing contact stress Segmental meniscectomy is equivalent to total meniscectomy in load-bearing terms Peak contact stresses increase proportionally to the amount of meniscus removed Clinical Relevance: Because the degree of meniscectomy leading to clinically significant outcomes is unknown, an surgical strategy is to preserve the greatest amount of meniscus possible
Bucket-handle tears
Vertical tear, Complete longitudinal tears where the inner fragment can displace into the notch and often become trapped. When the mobile version does not reduce spontaneously, the knee will often not be able to straighten and the knee will be described as locked
Does arthroscopic meniscal repair lead to successful outcomes in a range of tear types?
Vertical, longitudinal tears in the vascularised zone of the meniscus are the most commonly repaired meniscal lesions.34 However, improved understanding of meniscal pathophysiology and enhanced arthroscopic repair methods35 have broadened the indications for surgical repair in a range of tear types. A review evaluated the current evidence on the clinical success of repairing the following tear types: horizontal, radial, root and ramp lesions. high rates of success can be achieved in tear types that may not routinely be considered for repair. Horizontal Tears Radial Tears Ramp Lesions Root Tears
The articular cartilage surface can be damaged by:
Wear and tear - a joint that experiences a long period of stress can become damaged. This happens with ageing hyaline cartilage. Trauma- Athletes have a higher risk of suffering from articular damage, especially those involved in high impact sports. Lack of movement - Long periods of inactivity or immobility increase the risk of damage to the cartilage.
What is the clinical relevance of the different orientation of implants of the FAST-FIX FLEX Meniscal Repair System implants?
With this alignment, the puncture area through meniscus tissue is 25% smaller than that of FAST-FIX 360 System
The medial collateral ligament (MCL)
a flat band of connective tissue that runs from the medial epicondyle of the femur to the medial condyle of the tibia.2 It is a strong broad band3 found on the inner aspect of the knee joint and is the largest structure situated on the medial side.4 It is generally described in 3 layers15 :Layer I: Thin sheet that overlies the two heads of the gastrocnemius and the structures of the popliteal fossa.Layer II: Superficial layer of the MCL (sMCL). This is also called the 'tibial collateral ligament'. Layer III: Deepest layer of the MCL called medial capsular ligament, which is continuous with the medial joint capsule. It is one of four major ligaments that supports the knee.The MCL is also known as the 'tibial collateral ligament static stabilizers: Superficial MCL (sMCL) The sMCL is the largest medial knee structure. It courses from the femoral attachment 3.2mm proximal 4.8mm posterior to the medial epicondyle. Distally on the tibia, the sMCL is identified deep to the pes tendons and sartorius fascia. It has a proximal tibial attachment 12mm distal to the tibial joint line and a second stronger attachment 61.2mm distal to the joint line.4 Deep MCL (dMCL) The dMCL is a capsular thickening with a proximal meniscofemoral and distal meniscofemoral division with firm meniscal attachments in the middle portion.3 Posterior oblique ligament (POL) The posterior oblique ligament is the continuum of oblique fibers on the posterior aspect of the medial collateral ligament3 It consists of a superficial, central, and capsular arm. The central arm is the thickest and largest. Its femoral attachment lies approximately 1.4mm distal and 2.9mm anterior to the gastrocnemius tubercle on the medial femur. Its tibial attachment lies proximal to the anterior arm of the semitendinosus tendon attachment on the tibia. The structures that are considered dynamic stabilisers of the medial knee are the:3 semimembranosus complex quadriceps pes anserinus
Autologous Chondrocyte Implantation (ACI)
a procedure used to treat isolated full-thickness articular cartilage defects of the knee. Autologous chondrocyte implantation is a two-stage operative procedure. During the first procedure, a surgeon will harvest a small piece of articular cartilage from the patient's knee. This cartilage biopsy is then sent to a laboratory where the biopsy is treated in order to isolate cartilage producing chondrocytes. Once these chondrocytes are obtained, they are then expanded in number and sent back to the surgeon approximately 6 to 8 weeks later for implantation. The second-stage operation is an open procedure whereby a small patch is sewn over the articular cartilage defect. The chondrocytes that have been harvested and expanded are then injected underneath this patch where they adhere to the patient's knee to form what is known as hyaline-like cartilage. Matrix-induced Autologous Chondrocyte Implantation (MACI) is a next-generation procedure where chondrocytes are implanted in a biodegradable scaffold matrix and implanted into a cartilage defect.