Short term clinical results of single bundle ACL reconstruction, with a quadruple autologous hamstring graft, modified transtibial versus anteriomedial portal approach for femoral tunnel

Anteriior cruciate ligament injuries are known to be the most common spots injuries, and ACL reconstruction is widely used because of the low success rate of convservative treatment. This study was aimed to compare the short-terma functional results of modifying transtibial and transportal technique for femoral tunnel drilling. This Retrospective comparative case control study included 76 patients with an isolated ACL tear, operated with ST tendon autograft ACL reconstruction by the same surgical tea. 36 patients operated with a modified transtibial approach and 40 patients with an antreomedial approach for femoral drilling. The results of the current study revealed that the mean age in the series was 26 years; the majority of patients were male, only 6 patient's asses again after two years of surgery, by instability tests and lysholm scores reveal no significant differences between two group regarding anterioposterior and rotatory instability, also comparable lysholm score results. The Study concluded that modified transtibial femoral drilling of the femoral tunnel in ACL reconstruction surgery is still useful and give comparable results as tranportal drilling (AU)

Quantitative Analysis of Magnetization Transfer by Phase Sensitive Method in Knee Disorder

Magnetization Transfer (MT) imaging generates contrast dependent on the phenomenon of magnetization exchange between free water proton and restricted proton in macromolecules. In biological materials in knee, MT or cross-relaxation is commonly modeled using two spin pools identified by their different T2 relaxation times. Two models for cross-relaxation emphasize the role of proton chemical exchange between protons of water and exchangeable protons on macromolecules, as well as through dipole-dipole interaction between the water and macromolecule protons. The most essential tool in medical image manipulation is the ability to adjust the contrast and intensity. Thus, it is desirable to adjust the contrast and intensity of an image interactively in the real time. The proton density (PD) and T2-weighted SE MR images allow the depiction of knee structures and can demonstrate defects and gross morphologic changes. The PD- and T2-weighted images also show the cartilage internal pathology due to the more intermediate signal of the knee joint in these sequences. Suppression of fat extends the dynamic range of tissue contrast, removes chemical shift artifacts, and decreases motion-related ghost artifacts. Like fat saturation, phase sensitive methods are also based on the difference in precession frequencies of water and fat. In this study, phase sensitive methods look at the phase difference that is accumulated in time as a result of Larmor frequency differences rather than using this difference directly. Although how MT work was given with clinical evidence that leads to quantitative model for MT in tissues, the mathematical formalism used to describe the MT effect applies to explaining to evaluate knee disorder, such as anterior cruciate ligament (ACL) tear and meniscal tear. Calculation of the effect of the effect of the MT saturation is given in the magnetization transfer ratio (MTR) which is a quantitative measure of the relative decrease in signal intensity due to the MT pulse.

Indirect Signs of Magnetic Resonance Imaging of the Knee with Anterior Cruciate Ligament Tears: Comparison between Acute and Chronic ACL Tears / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to assess the differential features of indirect signs at magnetic resonance (MR) imaging in acute and chronic tears of the anterior cruciate ligament. MATERIALS and METHODS: Preoperative MR imagings of 71 patients (71 knees) who were confirmed as complete tear of anterior cruciate ligament (ACL) by arthroscopy were evaluated. On MR imagings of acute (n=47) and chronic (n=24) tear of ACL, and of the control group (n=31) , we reviewed bone bruise, posterior displacement of the lateral meniscus, posterior cruciate ligament (PCL) angle, and PCL line. RESULTS: Bone bruise was observed in 35 cases (74.5%) at acute tear and in 9 (37.5%) at chronic tear, and mean PCL angle was 122 and 106 degrees, respectively. These two signs were significantly different (p<0.05) . The presence of posterior displacement of lateral meniscus was in 26 cases (55.3%) at acute tear and in 12 (50.0%) at chronic tear. Positive PCL line was in 23 (48.9%) and in 16 (66.7%) cases, respectively. CONCLUSION: Bone bruise, posterior displacement of lateral meniscus, PCL angle, and PCL line were helpful indirect signs suggesting an ACL tear in MR imagings. Posterior displacement of lateral meniscus and PCL line were not affected by the time of ACL tear. Bone bruise in acute tear and PCL angle in chronic tear were very frequent.

Sighificance of MR Axial Image in the Dignosis of ACL tear

To determine the usefulness of MR axial images for diagnosis ACL tears, we reviewed MRIs of 67 patients with ACL tear confirmed by arthroscopic examination, retrospectively. There were 53 acute and 14 chronic tears. The axial MR images had a 97% sensitivity(acute: 96%, chronic: 100%). Findings of acute ACL tears on sequential axial imaging could be categorized as 1) diffuse swelling with abnormal substance signal in 14 cases(27.5%), 2) focal bulging or irregularity of medial border in 11 cases(21.6%) or 3) combination of the two in 26 cases(50.9%). Findings of chronic ACL tears also could be categorized as abnormally irregular thin fibers in 6 cases(42.9%) or nonvisualization(empty lateral wall) in 8 cases(57.1%). We concluded that MR axial images could provide additional useful information in the diagnosis of ACL tear.

Notchyplasty with Flexible Reamer in ACL Reconstruction

Arthroscopic unterior cruciate ligament reconstructions using bone-patelia 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 emphasiz,ed recent]y to prevent retear of the reconstrucled ACL causecl by impingement. However, until now, there is controversy ahout adequate amount of notchyplasty. Also, it is hard to examine the adequacy of notchyp]asty even in the aithroscopic field. The purpose of this paper is to describe the surgical technique of notchyplasty, using the flexible reamer and preliminary result of this procedure. In this study the results of ACL:reconstruction with notchyplasty which is made hy us were analized from January,1994 to December,1995. The results were as follows; 1. The notchyplasty with flexible reamer is the method tbat can be performed adequate amount of removal, and he obtained perfectly smooth notchplasty. 2. The range of motion of the affected knee joint was normal ROM after ppst operation 6 month. 3. In the last follow up, 2 cases were positive in anterior drawer test, 4 cases were positive in Lachmanns tesl., and Case was positive in Pivot shift test. 4. Average Lyshnlm knee scoring scale was 70 points al preoperative and 92 points at the last follow up.

Partial Tear of ACL at the Femoral Attachment of Posterolateral Bundle as a Cause of Knee Locking

OBJECTIVE: Locking of the knee is usually attributed to a tear of meoiscus, or to a loose body that rnechanically obstructs the motion of joint. A less frequently recognized cause of a locked knee is a partial tear of the ACL. The purpose of this study is to report that the partial tear of,the ACL at the femoral attachment site of posterolateral bundle provided a mechanical obstruction in the knW, and it is convicted the injury mechanism of isolated ACL. MATEIRALS AND METHODS: The author presents 16 cases in which the torn ACL was observed knee locking under arthroscopy fram February 1993 to June 1996. Patients ages ranged from 22 to 54 years. The mechanism of injuries were 6 sports activity (Ski 4, Soccer 1, Badminton 1), 4 slip down, 3 pedestrian car accidents and 3 unknown causes with especially low velocity injuries. Although the chief complain in each case was knee pain, all had locking knee that, on physical examination, locked from 5 to 20 of full extension, and 4 locked full flexion. The positive Lachman test was obtained 3 of the 16 paiients. Associated intraarticular injuries were 2 tears of the medial meniscus, 1 lateral meniscus. RESULTS: The average time to arthroscopy was 3 nonths with a range of 1 month to 10 rnonths. An arthroscopic diagnosis and treatment were performed and meniscal tears were ruled out as the cause of locking in all patients. The injury mechanism of isolated ACL was the hyperextensioo of the knee with leg I/R and especially low velocity injuries. The ACL was found to have a partial tear at the site of femoral attachment of an estimated P-L bundle. The torn segment of the ACL to become interposed between the lateral femoral condyle and the latera1 tibial condyle and to act as mechanical block was demcinstrated. CONCLUSION: In all cases, the torn portion of the ACL was excised under arthroscopy and knee locking was resolved.