**2.7 Advantages of 3-D SPGR**

190 Modern Arthroscopy

"arthrogram" effect, and allow indirect visualization of chondral lesions as well (Beltran,

In a comparison study between MR and anatomic section Hodler et al (1992) concluded that standard MRI does not consistently allow detection of focal articular cartilage defects. Commonly used MRI sequences are not reliable enough to be effective in the diagnostic

The role of MRI for the diagnosis of chondral lesions of the knee joint is still unclear, and the sensitivity of the method ranges from 15 to 96 percent (Friemert et al, 2003). In a prospective study by Friemert et al (2003) of how MRI can replace arthroscopy in the routine diagnosis of cartilage damage, they found that the MRI cartilage specific sequences have a sensitivity of 33 percent and specificity of 99 percent and positive and negative prediction values of 75 and 98 percent respectively. With gadolinium enhanced MRI the sensitivity was 53 percent and the specificity was 98 percent. The positive prediction value was 48 percent and the negative prediction value was 98 percent. They concluded that the MRI examination techniques recommended in the literature are not able to replace arthroscopy for the diagnosis of cartilage damage of the knee joint, and in view of the high specificity (97 to 98 %) MRI is suitable for identifying cartilage lesions. In view of the low sensitivity of MRI to cartilage injury, a cautious attitude towards an operative cartilage treatment is justified. Because that MRI can not replace arthroscopy for the diagnosis of cartilage damage and so arthroscopy still has to be seen as the method of

Currently the most widely used techniques for articular cartilage imagining by MR are fat suppressed proton-density weighted fast spin-echo sequences, and fat suppressed spoiled gradient recalled echo (SPGR) sequences (Kornaat et al, 2005). SPGR sequences are often chosen for cartilage volume and thickness estimation because the 3D acquisition, along with higher intensity cartilage signal, provides robust visualization of cartilage and detection of cartilage pathology. However, new MR imaging pulse sequences, specifically steady-state free precession (SSFP), have recently attracted attention for their optimal visualization of cartilage. The new sequences give greater cartilage intensity, increased cartilage and contrast-to-noise ratio and reduced imaging time than conventional pulse

Fat suppressed 3-D spoiled gradient recalled acquisition in the steady state (SPGR) MRI technique was compared with 2-D SPGR images and conventional T1 and T2 weighted spinecho and multiplanar by Disler et al (1994). They studied ten healthy volunteers and concluded that fat-suppressed 3-D SPGR imagining is an improvement over fat-suppressed spin-echo imagining because the fluid signal is diminished relative to cartilage. As the sequence essentially suppresses all stationary tissue, it is not useful in evaluating the fibrocartilage, ligaments or soft tissues of the knee. However the technique shows cartilage as an object of high signal intensity relative to adjacent tissues, giving the technique great

1980; Spritzer 1988; cited by Speer 1991).

evaluation of degenerative changes of articular cartilage.

choice for the evaluation of cartilage damage (Friemert et al, 2003).

**2.6 Comparison between 3-D SPGR and conventional MR imaging** 

**2.5 Best MRI sequences to visualize articular cartilage** 

sequences (Kornaat et al, 2005).

potential for evaluating this structure.

**2.4 Can MRI replace arthroscopy in diagnosis?** 

Fat-suppressed 3-D SPGR imagining has several advantages over conventional sequences. It generates positive contrast between cartilage and adjustment structures, making joint infusion unnecessary to show the cartilage margin (Kornaat et al, 2005).

Fat-suppression maximizes the contrast between cartilage and adjacent marrow, an improvement over T2–weighted spin-echo imagining, and minimizes chemical- shift artifact. Three-dimensional acquisition can generate very thin slices without loss of information.

In summary, fat-suppressed 3-D SPGR imagining of the knee provides a striking positive contrast between hyaline cartilage and adjacent structures, and may improve the accuracy of MR diagnosis of hyaline cartilage abnormalities (Disler et al, 1994).

The sensitivity of fat-suppressed 3-D SPGR imaging was compared with that of standard MR imaging for detecting hyaline cartilage defects of the knee, using arthroscopy as the standard of reference. Disler et al (1994) assessed 114 consecutive patients for hyaline cartilage defects of the knee with both standard MR imaging sequences and a sagittal fatsuppressed 3-D SPGR sequences. Forty eight patients with meniscal or ligament injury or persistent symptoms underwent subsequent arthroscopy. The standard MR and SPGR images of these 48 patients were then retrospectively analyzed for articular defects in a blinded fashion by two independent observers. Sensitivity, specificity, and intra-observer and inter-observer agreement were determined for the different imaging techniques. A quarter of the patients who went on to arthroscopy were found to have isolated hyaline cartilage lesions. The SPGR imaging sequences had a significantly higher sensitivity than the standard MR imaging sequences for detecting hyaline cartilage defects (75 to 85 % and 29 to 38 % respectively, p < 0.001, for each component). Significant differences in sensitivity were found for each surface except the trochlear and lateral tibial surfaces. No difference in specificity were found (97 % and 97 % respectively, p > 0. 99). Combined evaluation of standard MR and SPGR images gave no added diagnostic advantage (sensitivity 86 %; specificity 97 %; p > 0.42). Except for the lateral tibial surface, reproducibility among readings and between readers was excellent. The conclusion from the study was that fatsuppressed 3-D SPGR imaging is more sensitive than standard MR imaging for the detection of hyaline cartilage defects of the knee (Disler et al, 1996). In day-to-day practice a routine clinical MRI scan has low sensitivity in diagnosing chondral damage when compared with arthroscopic findings (Bobic, 2005).

Levy et al (1996) reported that preoperative MRI scans correctly identified 21 percent of the chondral lesions seen at arthroscopic examination. However, since 1996 the new awareness of the significance of chondral problems, due to extensive laboratory and clinical research, and various attempts to repair hyaline articular surface, has resulted in an increased interest in magnetic resonance imaging as a diagnostic and evaluation tool (Bobic, 2005).

 Development of refined MRI techniques and recent advantages in MRI technology appear to be very promising. Magnetic resonance imaging has the potential to replace the more conventional invasive techniques, like arthroscopy and biopsy, in the evaluation of articular cartilage damage and repair (Bobic, 2005).

#### **2.8 Significant of focal subchondral oedema**

Rubin et al (2000) retrospectively reviewed the MR studies of 18 knees with arthroscopically proven acute articular cartilage defects, noting the associated subchondral oedema.

Traumatic Chondral Lesions of the Knee Diagnosis and Treatment 193

of the animal or patient, the function of the joint, the structure of the joint, and the structure, composition and mechanical properties of the new tissue (Buckwalter, 1999). This approach to evaluating methods of restoring a cartilaginous articular surface assumes that the goal of any of these methods is to provide sustained improved joint function, and decrease joint symptoms in people with traumatic or degenerative joint damage. Tissues that differ from

There are several choices for the treatment of articular cartilage defects. For the last few years new techniques that aim to reestablish hyaline cartilage have been introduced. They include the use of cultured cells, bone mesenchymal stem cells, as well as tissue engineering (Morcacci et al, 2002). On the other hand, there are papers suggesting that minimum invasive, simple method, or even willful negligence of a surgical treatment, might also be effective in achieving good function of the joint (Morcacci et al, 2002). Messner and Maletius (1996) showed that without treatment 22 of the 28 patients had good to excellent function 14 years after surgery. Another study, Shelbourne et al (2003), showed that at ten years follow-up there was no significant difference between the outcomes of patients with ACL-associated untreated cartilage injury and patients with no cartilage injury. It is suggested that in certain conditions conservative treatment of cartilage defects should be also considered (Aroen et al, 1998). During the last decade, novel surgical techniques have been introduced and the mid-to

long-term functional results of those procedures are awaited (Morelli et al, 2002).

patients' subjective scores remain favorable (Messner and Maletius, 1996).

level, alignment, arthritis, joint stability, and severity of symptoms (Minas, 2000).

patellofemoral symptoms subsequent to surgery or injury (Morelli et al, 2002).

**3.3.2 Nonsteroidal anti-inflammatory drugs (NSAIDs)** 

The main objective of any treatment regimen is pain modulation, with secondary objective consisting of the restoration of joint function. Non-operative treatment attempts to achieve these goals, yet long-term follow-up reveal decreased objective knee function scores whilst

Operative management should be considered for patients who present with symptomatic partial thickness or deep chondral lesions, and for patients with intact osteochondral fragments, as commonly encountered in the skeletally immature and young adult. In the decision-making process of any treatment option, several factors must be taken into consideration, including defect size and location, acuteness of injury, age, desired activity

The goal of physiotherapy is to reduce swelling and maintain or improve knee function by focusing on quadriceps and hamstring strengthening. It may prove beneficial in the prevention and treatment of associated morbid conditions such as joint stiffness and

NSAIDs act by inhibition of prostaglandin synthesis and thereby function as modulators of pain and inflammation. Earlier works suggest that some NSAIDs may actually promote cartilage degeneration and progression to arthritis by its inhibitory action on proteoglycan

**3.1 Objectives of treatment** 

**3.3 Nonoperative treatment** 

**3.3.1 Physiotherapy** 

synthesis (Brandt, 1991).

**3.2 Indications of operative treatment** 

normal articular cartilage may achieve this goal (Buckwalter, 1999).

Subchondral oedema was defined as the focal region of high signal intensity in the bone immediately underlying an articular surface defect on a T2 weighted or short inversion time inversion recovery (STIR) images. In their study the subchondral oedema was found to be associated with chondral surface defects in 83 % (Observer 1) and 72 % (observer 2) of subjects. Focal subchondral oedema is commonly visible on MR images of treatable, traumatic chondral lesions in the knee. This MR finding may prove to be an important clue to assist in the detection of these traumatic chondral defects (Rubin et al, 2000). They postulate three possible mechanisms for the generation of this marrow oedema: the injury to the subchondral bone can (1) precede the articular cartilage injury, (2) occur at the same time as the cartilage injury, or (3) follow the cartilage injury. Support for the first possibility comes from animal studies of experimentally created chondral injuries that show injury to the overlaying cartilage by several weeks (Radin et al, 1973 and 1984; cited by Rubin et al, 2000). Marrow oedema shown on MR images is thought to reflect the initial injury to the overlaying cartilage by several weeks (Thompson et al, 1993; cited by Rubin et al, 2000). The support for the second possibility is that the initial force responsible for the cartilage fracture produces a transient depression of the articular surface that is transmitted to the subchondral plate. In this instance, the subchondral marrow oedema would represent a direct contusion, or true bone "bruise". The support for the third hypothesis is that the initial insult produces a cartilage defect large enough to expose the underlying bone to direct compression against the opposing articular surface once joint loading recommences (Minas et al, 1997; cited by Rubin et al, 2000).

Characteristic subchondral oedema revealed on fat-suppressed STIR images may alert the radiologist to the presence of a defect in the overlaying chondral surface that otherwise may have been overlooked (Rubin et al, 2000).

#### **3. Treatment of articular surface lesions**

Articular cartilage injuries are notorious for their inability to produce a healing response. The management of symptomatic lesions must take into consideration several patient factors before initiating a long-term treatment plan. Most, if not all, patients should have a trial of nonoperative measures in an attempt to alleviate symptoms (Morelli et al, 2002). Patients' not responding to treatment should be considered for surgical management (Morelli et al, 2002). Although a rapid development of diagnostic and therapeutic methods of articular cartilage lesions has been made, a problem of choosing the best treatment still persists. Isolated, particularly symptomatic, deep chondral lesions seem to be problematic (Widuchowski et al, 2007).

Experimental studies have shown that variations in the treatment of articular cartilage lesions can restore some form of cartilaginous articular surface, but formation or transplantation of cartilaginous tissue in an animal model does not prove that a given method has the potential to relieve joint symptoms, or improve joint function in humans (Buckwalter, 1999). The effort to restore cartilaginous articular surfaces has now reached the point where investigators should evaluate the results of experimental methods to restore cartilaginous articular surfaces, and identify the most promising approaches to the solution of clinical problems (Buckwalter, 1999). Important issues concerning the experimental models include the types of articular surface defects studied, the age of the animal, and differences in articular cartilage among species. Important considerations in assessing the outcome of procedures designed to restore an articular surface include the overall function of the animal or patient, the function of the joint, the structure of the joint, and the structure, composition and mechanical properties of the new tissue (Buckwalter, 1999). This approach to evaluating methods of restoring a cartilaginous articular surface assumes that the goal of any of these methods is to provide sustained improved joint function, and decrease joint symptoms in people with traumatic or degenerative joint damage. Tissues that differ from normal articular cartilage may achieve this goal (Buckwalter, 1999).

There are several choices for the treatment of articular cartilage defects. For the last few years new techniques that aim to reestablish hyaline cartilage have been introduced. They include the use of cultured cells, bone mesenchymal stem cells, as well as tissue engineering (Morcacci et al, 2002). On the other hand, there are papers suggesting that minimum invasive, simple method, or even willful negligence of a surgical treatment, might also be effective in achieving good function of the joint (Morcacci et al, 2002). Messner and Maletius (1996) showed that without treatment 22 of the 28 patients had good to excellent function 14 years after surgery. Another study, Shelbourne et al (2003), showed that at ten years follow-up there was no significant difference between the outcomes of patients with ACL-associated untreated cartilage injury and patients with no cartilage injury. It is suggested that in certain conditions conservative treatment of cartilage defects should be also considered (Aroen et al, 1998).

During the last decade, novel surgical techniques have been introduced and the mid-to long-term functional results of those procedures are awaited (Morelli et al, 2002).

## **3.1 Objectives of treatment**

192 Modern Arthroscopy

Subchondral oedema was defined as the focal region of high signal intensity in the bone immediately underlying an articular surface defect on a T2 weighted or short inversion time inversion recovery (STIR) images. In their study the subchondral oedema was found to be associated with chondral surface defects in 83 % (Observer 1) and 72 % (observer 2) of subjects. Focal subchondral oedema is commonly visible on MR images of treatable, traumatic chondral lesions in the knee. This MR finding may prove to be an important clue to assist in the detection of these traumatic chondral defects (Rubin et al, 2000). They postulate three possible mechanisms for the generation of this marrow oedema: the injury to the subchondral bone can (1) precede the articular cartilage injury, (2) occur at the same time as the cartilage injury, or (3) follow the cartilage injury. Support for the first possibility comes from animal studies of experimentally created chondral injuries that show injury to the overlaying cartilage by several weeks (Radin et al, 1973 and 1984; cited by Rubin et al, 2000). Marrow oedema shown on MR images is thought to reflect the initial injury to the overlaying cartilage by several weeks (Thompson et al, 1993; cited by Rubin et al, 2000). The support for the second possibility is that the initial force responsible for the cartilage fracture produces a transient depression of the articular surface that is transmitted to the subchondral plate. In this instance, the subchondral marrow oedema would represent a direct contusion, or true bone "bruise". The support for the third hypothesis is that the initial insult produces a cartilage defect large enough to expose the underlying bone to direct compression against the opposing articular surface once joint loading recommences

Characteristic subchondral oedema revealed on fat-suppressed STIR images may alert the radiologist to the presence of a defect in the overlaying chondral surface that otherwise may

Articular cartilage injuries are notorious for their inability to produce a healing response. The management of symptomatic lesions must take into consideration several patient factors before initiating a long-term treatment plan. Most, if not all, patients should have a trial of nonoperative measures in an attempt to alleviate symptoms (Morelli et al, 2002). Patients' not responding to treatment should be considered for surgical management (Morelli et al, 2002). Although a rapid development of diagnostic and therapeutic methods of articular cartilage lesions has been made, a problem of choosing the best treatment still persists. Isolated, particularly symptomatic, deep chondral lesions seem to be problematic

Experimental studies have shown that variations in the treatment of articular cartilage lesions can restore some form of cartilaginous articular surface, but formation or transplantation of cartilaginous tissue in an animal model does not prove that a given method has the potential to relieve joint symptoms, or improve joint function in humans (Buckwalter, 1999). The effort to restore cartilaginous articular surfaces has now reached the point where investigators should evaluate the results of experimental methods to restore cartilaginous articular surfaces, and identify the most promising approaches to the solution of clinical problems (Buckwalter, 1999). Important issues concerning the experimental models include the types of articular surface defects studied, the age of the animal, and differences in articular cartilage among species. Important considerations in assessing the outcome of procedures designed to restore an articular surface include the overall function

(Minas et al, 1997; cited by Rubin et al, 2000).

**3. Treatment of articular surface lesions** 

have been overlooked (Rubin et al, 2000).

(Widuchowski et al, 2007).

The main objective of any treatment regimen is pain modulation, with secondary objective consisting of the restoration of joint function. Non-operative treatment attempts to achieve these goals, yet long-term follow-up reveal decreased objective knee function scores whilst patients' subjective scores remain favorable (Messner and Maletius, 1996).

#### **3.2 Indications of operative treatment**

Operative management should be considered for patients who present with symptomatic partial thickness or deep chondral lesions, and for patients with intact osteochondral fragments, as commonly encountered in the skeletally immature and young adult. In the decision-making process of any treatment option, several factors must be taken into consideration, including defect size and location, acuteness of injury, age, desired activity level, alignment, arthritis, joint stability, and severity of symptoms (Minas, 2000).

#### **3.3 Nonoperative treatment**

#### **3.3.1 Physiotherapy**

The goal of physiotherapy is to reduce swelling and maintain or improve knee function by focusing on quadriceps and hamstring strengthening. It may prove beneficial in the prevention and treatment of associated morbid conditions such as joint stiffness and patellofemoral symptoms subsequent to surgery or injury (Morelli et al, 2002).

#### **3.3.2 Nonsteroidal anti-inflammatory drugs (NSAIDs)**

NSAIDs act by inhibition of prostaglandin synthesis and thereby function as modulators of pain and inflammation. Earlier works suggest that some NSAIDs may actually promote cartilage degeneration and progression to arthritis by its inhibitory action on proteoglycan synthesis (Brandt, 1991).

Traumatic Chondral Lesions of the Knee Diagnosis and Treatment 195

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#### **3.3.3 Intraarticular viscosupplementation and oral supplements**

Some preliminary studies suggest that hyaluronic acid, glucosamine, and chondroitine sulfate may have beneficial effects on articular cartilage. Hyaluronan appears to have two effects in the short-term: pain modulation and improved clinical function in early arthritis, and a reduction in the size of the chondral lesions (Evanich et al, 2001; Rolf et al, 2005). Similar results have been reported in trials using glucosamine, chondroitin sulfate, and manganese ascorbate. Glucosamine appears to exert its action by stimulating glycosaminoglycan synthesis, whereas chondroitin sulfate and manganese ascorbate inhibit protease activity thereby delaying progression of cartilage degeneration (Lippiello et al, 2000). However, before definitive conclusion can be drawn with respect to these substances, large-scale randomized controlled trials are warranted.

#### **4. Reference**


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**4. Reference** 


**1. Introduction** 

this field

footprints.

**2. ACL anatomy** 

surgical reconstruction of the ACL.

**9** 

**Contemporary Anterior** 

P. Christel1 and W. Boueri2 *1Habib Medical Center, Riyadh* 

> *1Saudi Arabia 2Lebanon*

**Cruciate Ligament Reconstruction** 

*2Bellevue University Medical Center, Mansourieh - El metn* 

The modern era of anterior cruciate ligament (ACL) reconstruction started in the early 1990's with the development of arthroscopic knee reconstruction procedures. Early on, graft fixation issues and, graft choice have been extensively debated. Then, the transtibial technique appeared (Rosenberg & Deffner, 1997; Chen et al., 2003). This was an easy and quick way to reconstruct the ACL which became soon adopted by most surgeons. However, the outcome was not always as good as expected (Freedman et al.,2003, Lewis et al., 2008) and with the re-discovery of the ACL anatomy and biomechanics, deep changes have been introduced in the way to reconstruct the ACL. This chapter reviews the main features related to ACL reconstruction and focus on the current state of the art in

The reader will find all the necessary details in the numerous articles which have been recently published in this field (Colombet et al.,2006; Edwards et al., 2006; Giron et al. 2006; Harner et al.,1999; Mochizuki et al., 2007; Petersen & Zantop, 2007; Purnell et al.,2008; Takahashi et al., 2006; Zantop et al., 2006,). We will summarize the main relevant points for

The ACL consists of at least two functional bundles, anteromedial (AMB) and posterolateral (PLB). The AMB is about twice long and big as compared to the PLB. The AM bundle is more sagitally oriented, limiting the anterior tibial translation while the more oblique PLB

Both bundles are parallel in full knee extension and, due to the location of their attachments, they cross each other when the knee bends. During knee flexion, the PLB shortens by more than 30%, while the AMB elongates by 15%. The PLB is tight when the knee is close to extension whereas the AMB is tensed when the knee bends. The range of length variation for the AMB varies between 1-3mm while the PLB exhibits a much widerrange, 4-7mm. In order to reproduce the ACL anatomy several studies have assessed and quantify the

(Fig 1), limits the internal rotation of the tibia (Zantop et al.,2007).

