Discussion

PAGE 102

Anterior Cruciate Reconstruction

Name: MBI

IC: 710204 08 5285

RN: 451904

Mr. MBI, a 32 year-old teacher twisted his left knee while playing sepaktakraw following his bicycle kick and landed on his left leg. The left lower leg twisted outward with a pop sound. He was not able to continue with the games after that. The swelling developed within two hours to the maximum. He went to the near by clinic and was treated with bandage and analgesic.

The pain and swelling disappeared after three weeks and he was able to work after that. He had no locking symptoms but had difficulties in going down and up stairs but worse on going downstairs. He tried to play sepaktakraw again but few times his knee gave way.

Examination of the left knee revealed the quadriceps was wasted. No knee effusion. He had tenderness at the medial joint line. The left knee has about 5o of fixed flexion and pain on extremen flexion beyond 135o. Lachman and anterior drawer test were positive grade 2. Modified pivot test was positive. Mc Murray test was negative

Diagnosis of anterior cruciate ligament was made. The option of anterior cruciate reconstruction and conservative treatment with lifestyle modification were discussed in lengthy with the patient and the expectation of reconstruction was explained. He opted for reconstructive surgery using bone patellar tendon bone autograft. The operation was done on the January 2003 without complication.

Closed chain exercise started immediate after surgery. He was follow up after 2 weeks post surgery. He was able to perform straight leg raising and sliding hip and knee movement. He was able to walk without crutches at 4 weeks. At 10 weeks his passive range of movement was 0-100o and active was 90o. He was happy with the surgical outcome.

Discussion

Sports-related injuries involving the knee are common, with the anterior cruciate ligament (ACL) being the most frequently injured ligament. Football, soccer, skiing, and basketball are the sports most implicated in this injury. The anterior cruciate ligament (ACL) ruptures occur > 200,000 in American population each year. (Albright et al, 1999) Severities of injury vary from mild sprain to complete disruption. Worst injury occur when the combination of medial collateral ligament, medial meniscus and anterior cruciate ligament occur in combination known as unhappy triad of ODonoghue (ODonoghue, 1950). Female athlete has a higher risk to ACL injury (Mary, 2002).

Anatomically anterior cruciate ligament is an intraarticular and extrasynovial ligament. The femoral attachment of the ACL is at the posterior part of the inner surface of the lateral femoral condyle. The ACL fibers fan out as they approach their tibial insertion, anterior and lateral to anterior tibial spine after passed beneath the transverse meniscus ligament. A few fibers of the ACL may blend with the anterior attachment of the anterior horn of the lateral meniscus as well as with the posterior attachment of the posterior horn of the lateral meniscus.

Girgis et al (1975) divided the ACL into two parts, the anteromedial band (AMB) and the posterolateral band (PLB) base on its tibial insertion. The fascicles of the AMB originate at the most posterior and proximal aspect of the femoral attachment and insert at the anteromedial aspect of the tibial attachment. Conversely, the fascicles of the PLB originate at the distal aspect of the femoral attachment and insert at the posterolateral aspect of the tibial attachment. The AMB is smaller than PLB. The length and orientation of the bundles change as the knee passes through motion. With passive flexion, the AMB tightens and the PLB is relatively lax. When the knee is extended, the PLB tightens and the AMB remains fairly tight but is not as predominant as the PLB.

ACL has limited ability to form scar tissue and to heal. Mid substance tear also incapable to heal. The ACL has a thin, vascularized envelope formed by the synovial lining. When this synovial sheath is torn during injury, blood dissipates within the joint and does not form a local fibrinous mesh at the site of injury and therefore compromise healing. Presence of free radical following the injury also compromised healing process.

The main ACL function is to resist anterior displacement of tibia in relation to femur in all flexion position especially at 15 to 30o of flexion. ACL help to resist hyperextension. It is also contributed to rotational stability of fully extended knee for both internal and external rotation. When the ACL is ruptured, the knee depends on other structure to prevent anterior translation and internal rotation. As the knee extend the secondary restrainer become lax and the tibia translated forward. It reduced back when the knee flexed around 20 to 30o.This subluxation and reduction movement known as pivot shift. This is caused by the action of iliotibial tract. Beynnon et al (1997) concluded the ACL functions as a major secondary restraint to internal rotation and as a minor secondary restraint to external rotation and varus-valgus angulation, particularly under weight-bearing conditions.

The classic history of a person sustaining an isolated ACL injury consists of a non-contact deceleration mechanism, usually occurring with a sudden stopping, cutting, or jumping maneuver with a pop sound and hyperextension knee. Usually patient cannot continue with the game due to unstable joint and haemarthrosis occur within hours. The likelihood is more than 70% that the patient has torn the ACL (De Haven, 1980). Contact injuries are more likely to result in multiligament injuries, as is seen with O'Donoghue's classic triad in which a direct blow valgus load on the knee results in injury to the ACL, medial collateral ligament (MCL), and medial meniscus such as lateral tackle of rugby player. The differential diagnosis for an acute traumatic hemarthrosis includes patellar subluxation or dislocation, osteochondral injury, peripheral meniscus tear, or intraarticular fracture. As happened to Mr. MBI, even without examination the diagnosis of anterior cruciate ligament rupture was apparent from history.

Patients with acute anterior cruciate ligament (ACL) injuries present frequently; the diagnosis should be suspected in all cases of acute haemarthrosis. More than 70 percent of patients with an acute traumatic haemarthrosis have an ACL tear, either partial or complete (Noyes et al, 1980). The first few hours before there is gross swelling and muscle spasm, is the best time to diagnose. Diagnosis of ACL tear can be made by clinical examination, arthrometer, MRI and arthroscopy.

The Lachman test has been reported to be the most useful clinical examination for acute and chronic ACL tears (Zarin et al, 1986). Anterior translation of the tibia in relation to the femur at 25-30o flexion with the absence of firm endpoint constitutes a positive Lachman test. Anterior drawer test is another indicative of ACL insufficiency but less sensitive as compared to Lachman because meniscus also contribute to the stability and resists translation. Pivot test is pathognomonic finding for ACL tear. The test is perfomed with hip slightly abducted and flexed with neutral rotation. The valgus is applied to the knee and the knee move from flexed position to extension with internally rotated tibia. The tibia will translate anteriorly at 25-30o flexion. Bach et al (1990) modified the pivot test by doing it under anaesthesia, with the tibia externally rotated and found the result was more reliable.Patients may demonstrate associated ligamentous laxity-related injury to the medial, lateral collateral, posterior cruciate, or posterolateral structures. Joint line tenderness and discomfort with rotation maneuvers or mechanical catching or locking symptoms are highly suggestive of an associated meniscal tear. The radiographs of the weight-bearing anteroposterior, lateral, and 45 posterioanterior views as well as a Merchant view of the patellofemoral joint are important to evaluate the medial and lateral joint spaces for degeneration or osteochondral injuries, subluxation and/or tilt of the patellafemoral joint as well as degeneration or osteochondral injury. Standard radiograph of the knee may demonstrate a pathognomonic sign of ACL injury, an avulsion of the lateral meniscal capsular ligament from a lateral tibial plateau known as Segond fracture.

The most accurate imaging for the ACL has been magnetic resonance imaging. (MRI) MRI was 93 % accuracy in detecting ACL pathology. Negative predictive value was 98% and positive predictive value was 76% (Fischer et al, 1991). MRI is expensive and poorly tolerated by many patients. Advantage of preoperative MRI is the detection of associated meniscal pathology, noninvasive and no radiation risk.

A normal ACL is a taut, straight anterior margin with low signal intensity on all pulse sequence. Because of fanlike configuration a gray slightly inhomogenous signal may not be seen in its entirely on a single sagital slice. Direct signs of tear is an amorphous edematous mass with focal increase signal T2-weighted images. Interruption of fibres with tears seen at midsubstance or at tibial or femoral attachment (Moore, 2003).

There are many arthrometers available and the KT-1000 is the most reliable. KT-1000 arthrometer reported specificity of 90 percent to 95 percent (Bach et al, 1990) (Daniel et al, 1985). The KT-1000 and Lachman examinations were more accurate in predicting complete acute ACL ruptures. DeHaven et al (1980) compared the results of arthroscopy with clinical anterior-drawer, pivot-shift, anteromedial rotatory instability and Lachman tests. False-negative results were found in 72 percent to 84 percent of conscious patients with the first three clinical tests but in only 16 percent with the Lachman test. Under anaesthesia, the pivot-shift test improved to 16 percent false-negative results and the Lachman test reached 100 percent accuracy.

Not all patients with ACL tear will have symptoms and progress to arthrosis. Patient who is at risk of giving way is most likely will benefit from reconstructive surgery. The incidence and progression of osteoarthritis following an anterior cruciate disruption is not only on the ligament tear but also on the associated injury e.g. meniscal tears, and osteochondral lesions.

MacDaniel and Dameron et al (1983) reported an average 10-year follow-up of untreated ACLs exhibited radiographic osteoarthritis in 16% and arthroscopic changes in 24%. They revealed a definite relationship between osteoarthritis and a varus deformity, medial menisectomy, and medial joint space narrowing. Sherman et al (1988) reported that patients with chronic ACL deficient knees and a menisectomy showed more progressive degenerative changes by radiographic criteria. But at 10 years all knees were doing poorly regardless of meniscal status. A higher incidence of osteoarthritis after lateral menisectomy or in knees with abnormal alignment also been reported by Allen et al (1984).

Reconstruction of the anterior cruciate ligament is carried out for stability and protection of the menisci and articular cartilage to alter the natural history of osteoarthritic progression. ACL reconstructive surgery will eliminate the pivot shift phenomenon (e.g. anterior subluxation of the tibia). In the anterior cruciate deficient knee, the posterior horn of the medial meniscus is the primary stabilizer to anterior translation and explains the high incidence of secondary medial meniscal tears in chronic ACL insufficiency (Shoemaker et al, 1986). Rupture of the posterior horn resulting in increased instability. Stabilization decreased the progression of arthritis. Preservation of meniscus as much as possible is the best warranty for slowing down degenerative arthritis after cruciate ligament injury (Shoemaker et al, 1986).

De Jour et al (1994) found that in patients who underwent an ACL reconstruction 2 years after injury, medial meniscal tears occurred in 30% and lateral meniscal tears in 7%. This increased to 60% for the medial meniscus and 15% for the lateral meniscus 10 years from injury. Shelton et al (1997) followed 44 conservatively treated ACL deficient patients prospectively who elected to return to sports with a brace. They had a normal meniscus on MR imaging. In the 29 patients requiring reconstruction, 23 menisci were torn in 17 patients. Finsterbush et al (1990) reviewed 98 patients who had an isolated ACL rupture at arthroscopy and found at a mean of 4.2 years, 71% of them has meniscal injury in repeat arthroscopy.

There is great controversy as to whether a reconstruction prevents osteoarthritis. Shino et al (1989) contributed the most thorough evaluation of osteoarthritic development by arthroscopically documenting the progression of articular cartilage lesions in 49 of 201 patients who received an allograft ACL reconstruction at a mean of 30 months after surgery. He found that patients who had pre-existing articular cartilage deterioration, loss of the corresponding meniscus, and had returned to strenuous activities, showed continued deterioration of the articular cartilage. These suggest ACL reconstruction for patient who wants to continue high level sport activity and reluctant life style modification.

Result of conservative management of ACL tears deteriorate with time. An ACL reconstruction result in a lesser degree or slower development of degenerative joint disease is not being proven. Even a prompt reconstruction and an excellent rehabilitation do not alter the natural history of a major intra-articular derangement of the knee. A recent well-controlled prospective study from Sweden has shown no significant difference in the number of professional soccer players who had retired from the sport and who had a similar degree of degenerative joint disease 7 years after tearing the ACL, regardless of whether they had undergone reconstruction or conservative management (Ross et al, 1995). Buss et al (1995) reported a good patient satisfaction level among who is > 30 years old, sedentary lifestyle and low athletic demand with conservative treatment. Casteleyn et al (1996) reported that patients who are willing to avoid high demand activities can have acceptable functional results after non-operative treatment of an ACL injury. The outcome does not appear to deteriorate with time and includes only very limited osteoarthritic changes.Advances in surgical treatment and reconstruction of the ACL have resulted in more aggressive treatment for this injury. General indications for ACL reconstruction surgery (Strover, 1993). In acute ACL injury are athletically active patient with high activity levels who wish to continue to participation cutting, pivoting and jumping sport, active patient with acute ACL tear and a grade lll of another primary restrain (e.g. medial collateral ligament, fibula collateral ligament or posterior collateral ligament) and athletic active patient with acute ACL tear and repairable meniscus tear. In chronic tear are functionally disabling giving away who are unwilling to modify their athletic participation, active patient with functional instability and repairable meniscus and patient who experience giving away with activity of daily living.

The ideal graft for anterior cruciate ligament (ACL) reconstruction should reproduce the complex anatomy of the ACL, provide the same biomechanical properties as the native ACL, permit strong and secure fixation, promote rapid biologic incorporation, and minimize donor site morbidity. The most popular and successful surgical replacements for the ACL have been biologic tissue grafts because of their potential for graft remodeling and integration into the joint. It can be as autograft or allograft. The advantages of autograft include low risk of adverse inflammatory reaction and no risk of disease transmission. Allograft use avoids donor site morbidity, decreases surgical time, and diminishes postoperative pain.

Various autograft choices have been used. The most common current graft choices are the bone-patellar tendon-bone graft (BPTB) and the quadruple semitendinosus/gracilis tendon graft. The bone-patellar tendon-bone graft is taken from the central third of the patellar tendon between 8 to 11mm with its adjacent patellar and tibial bone blocks. BPTB has high ultimate tensile load (approximately 2376 N), its stiffness (approximately 812 N/mm) (Woo et al, 1991), and the possibility for rigid fixation with its attached bony ends.

BPTB has been most commonly criticized for its potential graft harvest site morbidity. Patellofemoral pain is the most common, ranging from occasional symptoms to interference with activities of daily living and sports. However, similar rates of patellofemoral pain have been reported in ACL-deficient knees that have been treated nonoperatively or in knees reconstructed with hamstrings (Johnson et al, 1993). Therefore, the etiology of anterior knee pain following BPTB ACL reconstruction and cannot be entirely due to the graft harvest.

Shelbourne et al (1997) believes that immediate restoration of knee hyperextension following ACL reconstruction places the graft in the intercondylar notch preventing scar tissue formation and reduced the anterior knee problems seen following BPTB ACL reconstruction. Quadriceps weakness also may occur following BPTB, which is contributed by the injury and by the harvesting procedure. However, Stringhan et al (1996) reported no different between allograft and autograft to suggest weakness is related to harvesting procedure. Yasuda et al (1995) also demonstrated no different in quadriceps power between BPTB and Harmstring autograft. Weakness of quadriceps compare to hamstring only significant at 1 year but similar at 2 years (Corry et al, 1999).

A patch of numbness lateral to the incision from cutting the infrapatellar branch of the saphenous nerve and a tender residual scar are commonly seen following BPTB harvest. Both conditions usually improve, if not resolve completely over time and rarely cause functional impairment. Other complications include patella tendon rupture, patella fracture and patella tendonitis. Patellar tendon rupture is a rare complication of BPTB ACL reconstruction. Complications usually occur within 10 months but may occur after 3 or 6 years (Marmuto et al, 1996).

The use of the hamstring tendon graft is increasing with its relatively low donor site morbidity and preservation of the extensor mechanism. Hamstring tendon graft use has evolved from a single-strand semitendinosus tendon graft to a quadruple-strand semitendinosus/gracilis tendon graft, where both the semitendinosus and gracilis tendons are folded in half and combined. The dimension of a round, 10-mm quadruple semitendinosus/gracilis tendon graft is more comparable with that of the intact ACL, and its ultimate tensile load has been reported to be as high as 4108 N. The quadruple semitendinosus /gracilis tendon graft also provides a multiple-bundle replacement graft that may better approximate the function of the two-bundle ACL (Hamner et al, 1999).

The disadvantages are concern over tendon healing within the osseous tunnels, the lack of rigid bony fixation and weakening the hamstring. However, Yasuda et al (1995) reported, harvesting the semitendinosis and gracilis does not affect quadriceps muscle strength at all and reduce hamstring strength significantly only at 1 month after surgery in ipsilateral knee. Rodeo et al (1993) evaluated tendon-to-bone healing under physiologic loads in a dog model. At the 2, 4, and 8-week intervals all specimens failed by tendon pull out. At the 12 and 26-week time periods all grafts failed at the clamp or mid-substance. He recommends protecting the healing process following hamstring ACL reconstruction for at least 8 weeks. There is no different between BPTB and hamstring autograft in terms of ligament stability, range of motion, and general symptoms (Corry et al, 1999). But lower donor site morbidity, kneeling pain and less thigh atrophy at 1 year.

The quadriceps tendon graft for ACL reconstruction has also gained recent attention. Biomechanical studies have shown the ultimate tensile load of this graft to be as high as 2352 N. This replacement graft has been found to have adequate tensile properties, as well as size, for ACL reconstruction. The quadriceps tendon graft has become an alternative replacement graft, especially for revision ACL surgeries and for knees with multiple ligament injuries.

Graft typeUltimate strength (N)Stiffness (N/mm)

Intact ACL2160242

Bone-patellar tendon-bone (10 mm)237635

Quadruple hamstring graft410853

Quadriceps tendon (10 mm)2352463

Anterior tibialis3412344

Posterior tibialis3391302

Biomechanical properties of ACL Graft (Miller et al. graft selection in anterior cruciate ligament reconstruction. Orthop Clin N Am 2002; 33; 676).

The morbidity associated with autograft harvest and the supply of allograft has increased the interest in allograft. Allograft is now commonly used for multiple ligament reconstructions, revision ligament reconstructions, and for patients who are not high-performance athletes. Four areas are of particular concern when using allograft: immunogenicity of the allografts, preservation and secondary sterilization of the grafts, remodeling and its effects on mechanical properties and most importantly, the potential of transmission of disease. The decrease in tensile properties with sterilization and preservation as well as risk of inflammatory reaction and its slower biologic incorporation has been a concern.

The most commonly used allografts include BPTB, Achilles' tendon, hamstrings, anterior tibialis, and posterior tibialis. Allograft needs adequate preparation because of potential and risk of disease transmission. There have been three reported incidences of disease transmission from bonepatellar tendonbone allograft used to reconstruct the ACL (Conrad et al, 1995).

Allograft is usually preserved by deep freezing or freeze-drying. Deep freezing without drying has little or no effect on the mechanical properties of ligaments, with no significant differences in the stiffness, ultimate load, or modulus noted between treated and control ligaments (Jackson et al, 1991). However, freeze-thaw treatments can damage cells and matrices, resulting in inferior biomechanical properties.

Sterilization of allograft tissues must be optimal to avoid contamination but expensive and time-consuming. Secondary sterilization can be achieved by ethylene oxide or gamma irradiation, but each has detrimental effects on the allograft. Ethylene oxide derivatives remain on the tissue and can cause persistent synovitis, graft failure and cystic changes around the graft tunnels. Thus it is not recommended for allograft sterilization (Jackson et al, 1993) Gamma irradiation can reduce the risk of disease transmission; but, it also has adverse effects on the tensile properties of ligaments. Irradiation alters tissue morphology, during which collagen fascicles become separated and the ligaments become visibly crimped. Currently, allograft are usually harvested in a sterile environment and kept sterile by deep freezing, or low-dose irradiation is used to achieve sterilization. Animal studies shown that deep frozen gamma radiated ACL allograft have the potential to attain the biomechanical properties of the normal ACL. Salehpour et al (1995) compared human BTB treated with either no irradiation or 4-Mrad. No significant difference was seen at low functional loads determined by static and cyclic creep tests, but the 4-Mrad group had significantly decreased stiffness, maximal force, and viscoelasticity.

(Chapman s Orthopaedic Surgery ,3rd edition, LWW,2001)

Jackson et al (1993) reported in their animal study comparing goat patellar tendon allograft and autograft. Autografts had smaller increases in anteroposterior laxity, higher ultimate tensile load and more advanced biologic incorporation when compared with allograft-reconstructed knees. That indicates that allografts have slower incorporation than autografts at 6 months after surgery. Allograft tissue revascularizes as with autograft tissue and becomes viable after implantation. The rate of graft incorporation and remodeling are slower for allograft than autograft reconstructions. In addition the allograft tissue deteriorate after implantation. However, minimal differences between allograft and autograft reconstruction at 3 to 5 years of follow-up.

Noyes et al ( 1990 ) reported at a mean follow-up of 7 years that 78% of fascia lata and 82% of BPTB allografts had restored knee stability after acute ACL reconstruction with 14% overall failure rate,17% failure in chronic ACL ruptures, 8% with autograft BTB. He recommended BPTB use for primary ACL reconstruction and allograft for revision surgery or for special circumstances if autograft is not available.

Well designed rehabilitation program plays an important role in the functional outcome following anterior cruciate reconstruction surgery. There are two different rehabilitation programs for isolated anterior cruciate reconstructed patient; accelerated rehabilitation program and regular rehabilitation program. The accelerated program is used in young and active patient. It differ in the rate of progression in the various stage of rehabilitation and time needed before start running and return back to sport.

Following anterior cruciate reconstruction, joint stiffness, arthrofibrosis, quadriceps weakness, extensor mechanism dysfunction and donor site pain may occur. It could be a result of immobilization. Shelbourne et al (1990) reported an improved clinical outcome following accelerated rehabilitation program. Better strength and range of motion, fewer complications such as arthrofibrosis, laxity and failure, less patellafemoral pain and earlier return to sport.

Preoperatively, the aim of physiotherapy are to reduce pain, inflammation and swelling, to restore full range of movement, achieve normal gait, prevent muscle atrophy and mental preparation. Following surgery, emphasized on full knee extension and gradual restoration of flexion range of motion. Weight-bearing as tolerated to full weight-bearing at two weeks. Closed kinetic chain, proprioceptive and strengthening exercise are initiated within two weeks postoperatively. A combination of open chain and closed kinetic chain are incorporated and progress as tolerated. Functional activities such as running begins between 8 to 10 weeks, jumping between 10 to 14 weeks, cutting 12 to 16 weeks and gradual return to running and cutting sports at 4 to 6 months and jumping sports at 6 to 9 months (Wilk et al, 2003). The initial graft strength, graft fixation and graft maturation and incorporation have to be considered at every stage of rehabilitation program.

Conclusion

In our setting bone patella tendon bone graft is the first choice for anterior cruciate reconstruction with minimal intraoperative and postoperative complication.

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