The anterior cruciate ligament(ACL) is, perhaps, the most intriguing component of the knee joint. Initially referred to crucial ligament because of the cruciate or crossed arrangement or the anterior and posterior ligaments within the knee. the irony or the ACL being crucial to the well-being or the joint has only recently appreciated. The anterior cruciate ligament of human knee joint is a complex structure and its orientation, construct and biology arc directly related to the knee function as a constraint of knee joint motion. In addition to its functional role as a static stabilizer or the knee. the ACL has a unique neurovascular system. The vascular anatomy of the ACL plays a crucial role in the repair and reconstruction of the ligament, and the neuroreceptors found in its substance suggest a possible proprioceptive role for the ligament. The structural complexity of the ACL allows the ligament to function through the normal range of motion as a static stabilizer or the knee. hut it also makes the exact duplication of this structure very difficult. A comprehensive knowledge or the anatomy of the ACL can provide the orthopedic surgeon with a blueprint for the idealized repair and reconstruction of this most complex structure.

Biomechanics of the soft tissue arc different from that of bone. Soft tissue has characteristics of nonhomogeneous, no-linear, anisotropic, viscoelastic, and finite deformation. Biomechanics of ACL, one of the soft tissue, are briefly described : structural and mechanical properties, viscoelastic response, immobilization, kinematics and static function.

In the present paper the current clinical knowledge about proprioception is given for the shoulder, knee, ankle, elbow and the radiocarpal joint. Proprioceptive capabilities are decreased after knee joint injury such as anterior cruciate ligament. Joint position sense is significantly improved by cruciate reconstruction. Thus, we review of the articles for the proprioception of the anterior cruciate ligament of the knee joint. The present information on proprioception will influence our clinical practice in the future. We should choose surgical procedures that not only reconstruct the anatomy, but also the neurophysiologic feed-back mechanism.

Recently, the incidence of anterior cruciate ligament injury is rapidly increasing because many young Korean are actively participating in sports activities including basketball, skiing and soccer. Sometimes acute ACL injuries arc misdiagnosed as sprain because of pain and muscle spasm. An accurate physical examination and careful history taking are very important to diagnose the ACL injuries. Therefore author described the skill of history taking and the technique of physical examination to diagnose ACL injuries. The most sensitive test is the Lachman's test, which is performed with the knee in 200 of flexion, the femur stabilized with full flexed examiner's knee placed behind patient's distal thigh and one hand of examiner, and the proximal tibia grasped with the other. The pivot shift test is a passive motion test that attempts to subluxate the tibia anteriorly, then have it reduce rapidly. The pivot shift test is very sensitive test to diagnose the chronic ACL injuries.

MRI(magnetic resonance imaging) is very useful to visualize the anterior cruciate ligament (ACL) injury of the knee. Differential features of ACL injury at MRI according to acute and chronic stage should be evaluated to enable accurate assessment of the integrity or ACL. Distinguishing features of normal anatomy. acute and chronic injuries or ACL at MRI will be reviewed.

Anterior Cruciate Ligament (ACL) plays an important biomechanical role for the stability of knee joint. ACL injury often leads to injuries of articular cartilage, menisci, or other supporting structures, and subsequent development of degenerative arthritis. Controversies still exist in the best treatment modalities of ACL injuries. hut the author considers it most important to make the appropriate patient selection for operative reconstruction or nonoperative treatment. and describes the treatment principles of ACL injury, including diagnosis, patient selection and the treatment modalities for successful treatment of ACL injury.

The natural history of the anterior cruciate ligament(ACL)-deficient knee remains controversial. although numerous investigation have tried to ascertain the course that the knee would follow once the ACL has lost functional integrity. An extensive review of the literature performed according to symptoms. physical examinations, associated surrounding tissue injuries. returns to activity level and radiological changes in the knee joint. An active individual with a non-functioning ACL was susceptible to injury to the menisci and deteriorate the articular cartilage, followed radiographic changes. An activity levels in general also changed after injury. The most common symptom was pain. But instability varied in these individuals. Conclusively we believe that all these factors will eventually, if not initially, result in a symptomatic knee. which will result in significant limitations to the individual's desired level. So we recommend an aggressive approach in person who desired to return to a relatively active life style in young person as well as in middle aged individuals who have significant symptomatic ACL deficient knee.

A torn anterior cruciate ligament(ACL) is the most common serious ligamentous injury to the knee joint. The incidence of ACL tears seems to be increasing, at least partly as a result of the increasing participation of individuals of all ages in high-risk sports. The most commonly used graft source for ACL reconstruction is the autogenous bone-patellar tendon-bone graft unit. Despite a good success record. postoperative complications, such as infection, patellar contracture/patellar baja, patellar fracture, rupture of the patellar tendon, graft failure without reinjury, can occur following ACL surgery. The purpose of this paper is to provide guidelines regarding the key points of the reconstructive procedure in a sequence and how to prevent or minimize the complications that can follow ACL reconstructive surgery. We want this knowledge can help orthopaedic surgeons to understand the reasons for previous and current successes and failures of reconstruction of the ACL, and it can help them to plan the care of patients who have an injury of the ligament.

Various surgical techniques has been advocated for reconstruction of anterior cruciate ligament using the bone-patella tendon-bone graft. Recently endoscopic technique provides good clinical results, with minimal skin incision, accurate positioning of the graft to the femoral tunnel, and decreasing wear rate of the graft. But the graft-tunnel mismatch remains problematic in endoscopic technique. The purpose of this paper is to described causes of the graft-tunnel mismatch and to provide important steps to prevent or minimize the graft-runnel mismatch following anterior cruciate ligament while using the endoscopic technique. Our guideline for prevention of the graft-tunnel mismatch are as follows: (1) The tunnel should he positioned closely to isometric point as much as possible. (2) Anterior placement of the tunnel should be avoided. (3) The change of graft length should be within 2mm between flexion and extension position.

The all inside anterior cruciate ligament reconstruction technique places an anterior ligament substitutes within two bony sockets rather than hone tunnel. This approach is accomplished through arthroscopic three portal which avoids the surgical exposure and morbidity associated with creating traditional bone tunnel. This technique has several distinct advantages when compared with the traditional ACL reconstruction through the bone tunnels. It offers the surgeon a less morbid method for ACL reconstruction that positions an ACL substitute at the anatomic attachment sites of the original ACL with two bone sockets, obviating the need for traditional bone tunnels. Graft fixation at or near the anatomic attachment points of the original ACL minimizes creep with early range of motion and reduces the abrasive 'wind-shield wipe' motion of the graft which occur with bone plugs positioned inside bone tunnels. The sagittal posterior angle to the tibial socket increases fixation strength to pullout with anterior translation force for the tibia on the femur. This technique is not graft specific and can accomodate any graft in which graft length can be customized to the intraarticular native ACL length.

Numerous techniques of anterior cruciate ligament (ACL) reconstruction have been described in literature. All have inherent advantages and disadvantages. The central one-third patellar tendon and hamstring tendons are the most commonly used autogenous tissues for replacement of a torn anterior cruciate ligament. Although the central one-third patellar tendon is considered to be 'the gold standard' for replacement of torn ACL. equivalent results have been reported using hamstring tendon grafts. Autogenous hamstring grafts provide adequate strength while avoiding donor site morbidity associated with bone-tendon-bone harvest. $EndoButton^{\circledR}$ femoral fixation allows precise femoral tunnel placement without a second incison. The purpose of this article is to describe surgical techniques using a quadrupled semitendinosus tendon and $EndoButton^{\circledR}$ fixation, and review the results of replacement of ACL.

This article describes a modified arthroscopic technique of anterior cruciate ligament (ACL) reconstruction using quadrupled hamstring tendon graft. The autogenous semitendinosus and gracilis grafts are harvested without detachment of the tibial insertion. To obtain longer graft, the accessory tibial insertions of the hamstring tendons are dissected. The EndoButton(Acupex Microsurgical, Andover, MA) is used for femoral fixation and two spiked staples are used for tibial fixation in a belt buckle fashion. Then the residual anterior laxity is restored by additional absorbable interference screw fixations. In this technique. more viable graft is obtained and firmer distal fixation is achieved by preservation of the tibial insertion of hamstring tendons.

Good stability and complete range of motion should be the ultimate goal of a rehabilitation program after ACL reconstruction. In previous years. the rehabilitation of the ACL reconstructed knee focused on protecting the new ligament by blocking terminal knee extension, hut, despite good stability, this approach led to numerous postoperative complications. Nowadays, most of surgeons agree the accelerated rehabilitation program based on the concept of ligamentization and clinical experience. Accelerated rehabilitation program consists of maintain of full extension of the knee, early weight bearing and prompt recovery of ROM, and closed kinetic chain exercise. Meeting this goal requires effective communication between-members of the health care team-the physician, physical therapist, atheletic trainer, and the patient. We have to know the importance of rehabilitation, knowlege about the physical therapy, and to introduce for special physical therapist and equipment.

There has been a controversy about the effectiveness of the synovectomy of the knee in the rheumatoid arthritis. So we studied to determine if the arthroscopic synovectomy of the knee was of benefit in the rheumatoid arthritis. We ana lysed 25 knees of 15 patients who underwent the arthroscopic synovectomy of the knee joint for their rheumatoid arthritis from Jun. 1995 to Oct. 1996. The average follow-up period was 20.1 months($12\~28$ months). The results were as follows; 1. Satisfactory results were obtained in 20 knees $(80\%)$ for the pain and the effusion each, 23 $(92\%)$ for the range of motion and 19 $(76\%)$ for the functional capacity. 2. In the overall results for the pain. effusion. range of motion and the functional capacity. we obtained excellent results in 14 knees $(56\%)$ and satisfactory results in 9 knees $(32\%)$. 3. In the patient's self assessment, 11 patients $(44\%)$ were delighted and 10 patients $(40\%)$ were satisfactory. 4. In the overall results according to the articular cartilage damage, satisfactory results were obtained in 15 $(93\%)$ out of 16 knees in Grade I and II, and 6 $(75\%)$ out of 8 knees in Grade III and IV. In conclusion, arthroscopic synovectomy could be one of very useful treatments for the rheumatoid knee. But further study is needed to get the long-term results of the synovectomy because there's many reports saying gradual decrease of good results with increasing time. And continuous and proper medical treatment including DMARDs, is needed to effectively control the rheumatoid arthritis even after the synovectomy.

Acute patellar dislocation is a painful, terrifying experience that always occurs suddenly. The recurrence is unfortunately common and each experience is just as painful to the patient. With each acute dislocation, additional intraarticular derangement occurs. Therefore the goals of treatments are not only to relieve acute pain by prompt reduction of the dislocation but also to remove any chondral or osteochondral fragments that may be present within the knee joint and to restore normal patellofemoral anatomy, thereby preventing recurrent dislocation and avoiding future patellar subluxation. To present the details of arthroscopic medial retinacular repair in acute patellar dislocation. we report 2 patients with treatment of acute patellar dislocation with osteochondral loose body.

Discoid meniscus has been well known to a frequent anomaly of meniscus and much reported in diagnosis and treatment. But, associated X-ray findings have not been known well. We reported its significance of X-ray findings in discoid meniscus. From May 1995 to May 1997, 31 cases of discoid meniscus were compared with 51 cases of nondiseoid meniscus both confirmed by arthroscopy, with simple X-my findings. Both groups were evaluated by X-ray findings in view of lateral joint space widening, peripheral spur of lateral joint space, sclerotic change of lateral tibial plateau, concave lateral tibial plateau, flattening of lateral femoral condyle, hypoplasia of lateral femoral condyle and high riding fibula. The results of analysis were as follows: 1. Widening of lateral joint space, sclerotic change of lateral tibial plateau and cupping of lateral tibial plateau were statistically significant in discoid meniscus. 2. X-ray findings in discoid meniscus were not associated with patient's injury history and symptom duration. 3. Other X-ray findings were not related in discoid meniscus significantly. X-ray findings with patient's history and physical examination arc helpful in the diagnosis of discoid meniscus.

Congenital deficiency of the anterior cruciate ligament (ACL) is a rare disorder that has been reported in association with other knee dysplasia like as congenital knee dislocation. congenital short femur, congenital absence of menisci, congenital ring meniscus, and thrombocytopenia-absent radius syndrome. There has been no published explanation about the etiology of bilaeral ACL deficiencies without other abnomality. The patient of congenital ACL deficiency must be carefully inspected about combined anomaly. Those efforts may be helful in treatment or ACL deficient patients and evaluation of pathophysiology or ACL deficiency. However there has not been a ruptured congenital deficiency of the ACL without other dysplasia or the knee and other congenital skeletal abnomalities. We reported a case of symptomatic bilateral congenital deficiencies of the ACL which have not been associated with other skeletal abnormalities.

저자들이 전방십자인대 파열과 함께 전방 불안정성을 보인 2례를 보존적으로 치료하여 좋은 임상적 결과를 얻은 바를 고려할 때, 급성기에 전방십자인대가 파열된 경우에도 전방십자인대를 싸고 있는 활액막이 파열되어 없어지지 않고 비교적 연속성이 잘 유지된 경우에는 보존적으로 치료함으로써 좋은 결과를 기대할 수 있을 것으로 사료되며 아울러 십자인대가 손상받았을 때 스스로 복원 능력이 있는 지에 대하여 새로운 연구가 필요하리라 사료된다.

We have studied the results of reconstruction by freeze-dried patellar allografts or patellar autografts in ACL-deficient patients prospectively. From January 1995 to December 1995, we performed ACL reconstruction using an arthroscopic-assisted technique with patellar autografts in 21 patients and patellar allografts in 13 patients. Minimum followup time was 1 year(average 26 months). All patients were evaluated by using KT-2000 arthrometer and MRI as well as by physical examination. Final results were rated as satisfactory or unsatisfactory by using a modified Feagin knee scoring scale. Good or excellent were considered to have satisfactory results and fair or poor were considered to have unsatisfactory results. As measured by the KT-2000, 19 cases$(90.5\%)$ had a 5-mm or Jess side-to-side differential, a satisfactory results in autograft group, 2 cases of unsatisfactory results had joint instability. In allograft group, 10 cases$(76.9\%)$ had a 5-mm or less side-to-side differential, a satisfactory results, 3 cases of unsatisfactory results had joint instability including postoperative infection(1 case). In conclusion, the results of ACL reconstruction with autografts were better than those with allografts. The problem of allograft reconstruction were rehydration, aseptic control and improper mechanical tensioning. So, we thought that success of allograft reconstruction was depended on careful implant preparation including pretensioning technique.

Arthroscopic anterior cruciate ligament reconstructions using bone-patella tendon-bone have been considered the best method by which others are compared. The notchyplasty is one of the important steps of this procedure and it is emphasized recently to prevent retear of the reconstructed ACL caused by impingement. However, until now, there is controversy about adequate amount of notchyplasty. Also, it is hard to examine the adequacy of notchyplasty even in the arthroscopic field, The purpose of this paper is to describe the surgical technique of notchyplasty, using the flexible reamer and preliminary result of its operation. In this study the results of ACL reconstruction with notchyplasty which is made by us were analized from January. 1994 to December, 1995. The results were as follows: 1. The notchyplasty with flexible reamer is the method that can be obtained adequate amount of removal, perfectly smooth notchyplasty. 2. The range of motion of the affected knee joint was normal ROM after post operation 6 month. 3. In the last follow up, 2 cases were positive in anterior drawer test 4 cases were positive in Lachmann's test and 1 knee was positive in Pivot shift test 4. Average Lysholm knee scoring scale was 70 points at preoperative and 92 points at the last follow up.

전방십자인대의 일차수복술이나 재건술후에 장기간의 비체중부하가 필요한지를 결정하기 위해서 일차수복술을 시행한 96례와 재건술을 시행한 82례등 총 178례를 대상으로 술후 체중부하시기에따라 두군으로 나누어 비교분석 하였다. 모든 례에서 술후 보조기를 착용하였고 120례에서는 술후 첫6주간 점차적으로 관절운동범위를 증가를 시키고 다음 6주간은 완전운동범위 회복상태에서 유지후 술후 12주에 체중부하를 허용하였으며 나머지 58례에서 술후 완전신전상태에서 즉시 체중부하를 시켜서 정기적으로 Lachman검사, KT 2000을 이용하여 불안정성여부를 관찰하였다. 평균 추시기간은 4.2년(2년$\~$6년)이었고 불안정성에 대한 평가는 AMA 분류에 따랐다. 최종추시상 모든환자에서 1+이상의 불안정성은 발견되지 않았으며 술후 12주에 체중부하를 한군에서 1a+가 104례$(86.7\%)$, 1b+군이 16례$(13.3\%)$로 관찰되고 즉시 체중부하를 한 군에서 1a+가 51례$(87.9\%)$, 1b+가 7례$(12.1\%)$에서 보였으나 통계적으로 의미있는 차이는 없었다(P>0.05). 본연구의 결과로 전방십자인대 일차수복술이나 재건술후 신전보조기를 착용시키고 즉시 보행을 시키는 것이 술후 슬관절의 불안정성에 영향을 주지 않으며 안전한 재활방법으로 생각된다.

The purpose of this study is to compare the results between conventional and accelerated rehabilitation program following ACL reconstruction using bone-patellar tendon-bone. Conventional rehabilitation focused on protecting the new ligament by blocking terminal extension and avoiding active quadriceps function in the terminal degrees of extension. But there is current trend toward early postoperative mobilization and intensive. so called 'accelerated', rehabilitation stressing hyperextension of the knee. The results of intraarticular ACL reconstruction with conventional and accelerated rehabilitation were prospectively compared for one year postoperatively in a series of 27 patients. Range of motion and thigh circumference were checked preoperatively, and weekly up to 8 weeks, 3 months. 6 months, and 1 year postoperatively. Stress radiologic test, KT-1000 arthrometer. Cybex II dynamometer were checked in preoperatively, and 3 months, 6 months, and 1 year postoperatively. There were no differences of objective stability and restoration of muscle power. But the accelerated group had a low incidence of extension loss. excellent range of motion, and less difference of thigh circumference. We concluded that accelerated rehabilitation program is recommendable due to superiority in terms of range of motion, especially less extension loss without increasing laxity of knee joint.