The Efficacy of Nerve Conduction Study on Tarsal Tunnel Syndrome / 대한족부족관절학회지

PURPOSE: Nerve conduction study (NCS) test is a standard diagnostic study of the tarsal tunnel syndrome. The purpose of this study was to determine the relation between the results of the NCS and postoperative clinical results. MATERIALS AND METHODS: From June 2004 to July 2015, 104 patients were diagnosed with tarsal tunnel syndrome and treated surgically. Of 104 patients diagnosed through NCS preoperatively and postoperatively, 41 patients were included in this study. There were 23 male and 18 female patients with mean age of 49.2 years old and the average follow-up period was 15.5 months. NCS, pain visual analogue scale (VAS) score, and subjective satisfaction were examined preoperatively and postoperatively. RESULTS: On the preoperative NCS, 32 patients (78.0%) were positive and 9 patients (22.0%) were negative, and 32 positive NCS patients consisted of 9 positive (28.1%), 16 improved (50.0%), and 7 negative (21.9%) postoperatively. VAS score was 7.4 preoperatively and 4.4 postoperatively. According to satisfaction, there were 8 excellent (19.5%), 21 good (51.2%), 6 fair (14.6%), and 6 poor (14.6%) patients. For 32 patients who were positive on the preoperative NCS, the postoperative VAS score was 4.87 and there were 7 excellent (21.9%), 16 good (50.0%), 4 fair (12.5%), and 5 poor (15.6%) patients. Sixteen patients were negative on the postoperative NCS, with a VAS score of 3.75, 1 excellent (6.3%), 11 good (68.8%), 2 fair (12.5%), and 2 poor (12.5%). There was no statistical correlation between the preoperative NCS and postoperative VAS score (p=0.10), between preoperative NCS and postoperative satisfaction (p=0.799), between preoperative NCS and postoperative VAS score (p=0.487), and between postoperative NCS and postoperative satisfaction (p=0.251). CONCLUSION: For patients diagnosed with tarsal tunnel syndrome and treated surgically, NCS showed little correlation with postoperative result.

Comparison of Complete Distal Release of the Medial Collateral Ligament and Medial Epicondylar Osteotomy during Ligament Balancing in Varus Knee Total Knee Arthroplasty

BACKGROUND: During ligament balancing for severe medial contracture in varus knee total knee arthroplasty (TKA), complete distal release of the medial collateral ligament (MCL) or a medial epicondylar osteotomy can be necessary if a large amount of correction is needed. METHODS: This study retrospectively reviewed 9 cases of complete distal release of the MCL and 11 cases of medial epicondylar osteotomy which were used to correct severe medial contracture. The mean follow-up periods were 46.5 months (range, 36 to 78 months) and 39.8 months (range, 32 to 65 months), respectively. RESULTS: There were no significant differences in the clinical results between the two groups. However, the valgus stress radiograph revealed significant differences in medial instability. In complete distal release of the MCL, some stability was obtained by repair and bracing but the medial instability could not be removed completely. CONCLUSIONS: Medial epicondylar osteotomy for a varus deformity in TKA could provide constant medial stability and be a useful ligament balancing technique.

Treatment of Superficial Peroneal Nerve Entrapment Syndrome under Local Anesthesia using Ultrasonogram / 대한족부족관절학회지

PURPOSE: To review the outcomes of surgical treatment for superficial peroneal nerve entrapment. MATERIALS AND METHODS: Ultrasonogram was used for diagnosis and surgical treatment. Seven superficial peroneal nerve entrapment were surgically treated with follow up of average 16 months (range, 6~29 months). Three patients were male and four patients were female with mean age 36.7 years (range, 19~51 years). Four cases developed after repetitive ankle sprain and three cases had no etiology. RESULTS: Operation was performed mini-open and subcutaneous fasciotomy under local anesthesia. The results were excellent in two cases, good in four cases, fair in one case. CONCLUSION: Ultrasonogram was useful for diagnosis and surgical treatment of superficial peroneal nerve entrapment syndrome.

Recurred Intraneural Ganglion on Superficial Peroneal Nerve (A Case Report) / 대한족부족관절학회지

Intraneural ganglilon of superficial peroneal nerve was rare condition around foot and ankle. we experienced a case of recurred intraneural ganglion of superficial peroneal nerve on foot. We treated the case with idendify of intraarticular branch of ganglion. We report the case with a review of literature.

Relationship between Tibial Bone Defect and Extent of Medial Release in Total Knee Arthroplasty

PURPOSE: To understand the relationship between tibial bone defect and extent of medial release in total knee arthroplasty. MATERIALS AND METHODS: We evaluated 32 knees in 22 patients with variable degrees of tibial bone defect on medial plateau has undergone total knee arthroplasty. In this study, 31 cases had been diagnosed as degenerative osteoarthritis and 1 case was osteonecrosis. We excluded cases with infection, traumatic arthritis, or neuropathic joints. With regard to gender, 29 cases were female and 3 cases were male. The following relationships were analyzed: preoperative degrees of tibial bone defect and varus deformity; the femorotibial angle of both weight-bearing whole extremity radiogram, distractive stress radiogram, and the extent of medial release. RESULTS: Average tibial bone defect was 9.8+/-4.1 mm. Average femorotibial angle on weight-bearing whole extremity radiograph was varus 10.0degrees+/-6.2degrees. Average femorotibial angle on distractive stress radiograph was varus 0.7degrees+/-4.6degrees. Statistically the extent of medial release showed no significant relationship with the degree of tibial bone defect and femoro-tibial angle of whole extremity radiogram. However, it revealed a statistically significant relationship with the femorotibial angle on distractive radiogram (r=0.465, p=0.007). CONCLUSIONS: Preoperative distractive stress radiograph might be a useful method to predict the extent of intraoperative medial release during total knee arthroplasty.

A Comparison of the Clinical and Radiographic Results of Press Fit Condylar Rotating-Platform High-Flexion and Low Contact Stress Mobile Bearing Prosthesis in Total Knee Arthroplasty: Short term Results

PURPOSE: This study compared the results of rotating-platform high-flexion (RP-F) total knee arthroplasty with low contact stress (LCS) for clinical and radiographical assessment after a short-term period. MATERIALS AND METHODS: 68 total knee arthroplasties using a RP-F and LCS system were analyzed retrospectively. Thirty-five of the 68 were osteoarthritic knees and were followed-up for more than 2 years. The clinical evaluation included range of motion (ROM), Knee Society Knee Score and Function Score (KSKS and KSFS), tailor position and kneeling. The radiographic evaluation included femorotibial angle, position of implants, radiolucent line and position of patella. RESULTS: The postoperative ROM, KSKS, and KSFS improved statistically in both implants. Comparing RP-F with LCS there were statistically no differences in ROM (p=0.863), KSKS (p=0.835), KSFS (p=0.535) and tailor position (p=0.489). There were no significant radiographic differences. CONCLUSIONS: Total knee arthroplasty with RP-F and LCS showed similar clinical and radiographic results; it also showed excellent and predictable results at the short-term follow up. However, in RP-F there was 1 case of early osteolysis, 1 case of patella clunk syndrome and 1 case of painful patella crepitus; therefore, further case studies and follow-up are needed.

Relation between Second-look Arthroscopic Findings and Clinical Results after Double Bundle Anterior Cruciate Ligament Reconstruction

PURPOSE: This study examined the relationship between the findings of a second-look arthroscopy and clinical results in double bundle anterior cruciate ligament (ACL) reconstruction using hamstring tendons fixed with a Ligament Plate(R). MATERIALS AND METHODS: Twenty eight cases of a double bundle ACL reconstruction using hamstring tendons were retrospectively reviewed. The follow-up period was more than 1 year and all cases were reviewed by second-look arthroscopy. The average follow-up period was 20.6 months (range: 12-34 months). In second-look arthroscopy, the anteromedial (AM) bundle and posterolateral (PL) bundle of the grafts were evaluated based on the tension, rupture and synovial coverage. Clinical evaluation was assessed using the Lysholm score, international knee documentation committee score, Hop test, Lachman test, pivot shift test, KT-2000 arthrometer and anterior drawer stress radiograph using Telos(R) in 30degrees knee flexion. The correlation between the arthroscopic findings of the grafts and the instability tests was evaluated. RESULTS: The AM graft was evaluated as being taut in 89.3% and lax in 10.7%, and the PL graft was assessed as being taut in 71.4% and lax in 28.6% according to the tension. The AM and PL grafts were evaluated as 'no rupture' in 78.6% and 'partial rupture' in 21.4%. There was no 'complete rupture' in any graft. The AM grafts were found to be good in 53.6%, fair in 35.7% and poor in 10.7%; the PL grafts were assessed as good in 50.0%, fair in 28.6% and poor in 21.4% according to the synovial coverage. The AM graft tension showed statistically significant results regarding both the Lachman test (rho=0.743, p<0.001) and degree of rupture (rho=0.438, p=0.020). The PL graft tension showed statistically significant results regarding both the pivot shift test (rho=0.548, p=0.003) and the degree of rupture (rho=0.663, p<0.001). CONCLUSION: Double bundle ACL reconstructions using hamstring tendons show good biological and clinical results. The graft tension and the degree of rupture show a statistically significant relationship to the stability of the reconstructed joint. On the other hand, the synovial coverage did not show a significant result.

Delayed Knee Locking after Complicated Anterior Cruciate Ligament Reconstruction Despite Good Stability Using A Bio-Transfix

We describe a case of delayed cyst formation that presented as intermittent knee locking after complicated anterior cruciate ligament (ACL) reconstruction using a Bio-TransFix implant in a 21-year-old male patient. During femoral fixation, we could not pull out the guide wire that was temporarily used for the femoral fixation. However, stability was good, and the guide wire was not removed. This was shown to be a wrong type of fixation in a later study. During follow-up, the patient was satisfied and stability was relatively good until 18 months post-operatively. From the 2nd post-operative year, he experienced intermittent knee swelling and locking and pain around the lateral femoral condyle. Follow-up magnetic resonance imaging showed a large cyst around the broken wire tip, but the reconstructed ACL was fine.

Surgical Treatment of Habitual Patella Dislocation with Genu Valgum

Habitual dislocation of patella is a rare disorder. Sometimes it is associated with angular deformity such as genu valgum. We experienced habitual patella dislocation associated with genu valgum that was treated with corrective osteotomy of distal femur and soft tissue realignment procedure including lateral release and medial reefing.

Clinical Result of Modified Percutaneous Repair Technique of Ruptured Achilles Tendon / 대한족부족관절학회지

PURPOSE: To investigate the results of percutaneous repair technique of Achilles tendon ruptures, and to describe the surgical technique. MATERIALS AND METHODS: We retrospectively analyzed the outcomes of 73 patients with ruptured Achilles tendon from October 1995 to September 2009. 28 patients were excluded due to short follow up period. 34 patients were male and 11 patients were female. The mean patient age was 37.19 (10~62) years. The location of rupture site was 6.58 cm proximal to the tendon insertion into the calcaneus on average. Mean follow up period was 55 months and All patients were surgically repaired using percutaneous technique with sural nerve isolation. RESULTS: Arner-lindholm score were excellent in 32 (71%), good in 12 (27%), poor in 1 (2%) case. 44 cases (98%) had the score more than good. Mean American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot function score was 92.93 (67~100). We had 1 case of superficial infection, 1 case of soft tissue irritation by suture knot. CONCLUSION: Percutaneous repair with sural nerve isolation in treating ruptured Achilles tendon showed low complication rate and reliable clinical outcome.

Subtalar Distraction Arthrodesis Using Frozen Allobone Graft by Interpositional Structural / 대한족부족관절학회지

PURPOSE: Subtalar distraction arthrodesis is useful treatment option for restore hindfoot alignment. but, using structural autograft have high risk of donor site morbidity. Recently, by replacing the structural allograft has been reported satisfactory clinical results. Therefore, the authors reviewed the results of subtalar distraction arthrodesis using a structural allograft, retrospectively. MATERIALS AND METHODS: From January 2008 to May 2010, 12 patients (12 feets; 9 male, 3 female) underwent subtalar distraction arthrodesis using frozen structural allograft. 9 cases were calcaneal malunion, 2 were nonunion or malunion after subtalar arthrodesis, 1 was other cause. Mean age was 38.9 (12~66) years old and follow up period was 16.5 (12~36) months. Surgical was performed with posterolateral approach and tricortical allobone block of frozen femoral neck was used. Analysis was done with retorspective manner to evaluate preoperative, postoperative, and final follow up radiologic measurement and AOFAS ankle-hindfoot scale. RESULTS: There was statistically significant increase (p<0.05) of ankle-hindfoot scale from preoperative 27.5 points to postoperative 72.5 points, talocalcaneal height by 6.62 mm, calcaneal pitch angle by 5.73 degrees, lateral talocalcaneal angle by 6.38 degrees and significant decrease (p<0.05) of tali-1st metatarsal angle by 5.23 degrees. 11 feet (91.7%) acquired bony union and it takes average 5.1 months. Final post-operative result revealed talocalcaneal height changed by 2.57 mm, calcaneal pitch anble, lateral talocalcaneal angle, talar-1st metatarsal angle were changed by 2.63 degrees, 1.62 degrees, 1.18 degrees, respectively (p<0.05). 3 cases of partial osteonecrosis of posterior facet of calcaneus were observed in operation field, 4 cases of complication were developed (1 case of nonunion, 1 collapse of allobone graft, 1 screw loosening, 1 superficial skin necrosis). CONCLUSION: Subtalar distraction arthrodesis using frozen structural allobone graft is useful alternative treatment method of arthrodesis with structural autobone graft.

Intraneural Ganglion Cyst in Foot and Ankle / 대한족부족관절학회지

PURPOSE: Pathogenesis of intraneural ganglion is controversial, however, the synovial theory that the intraarticular region is the origination of disease has come into the spotlight nowadays. But there are a few researches about intraneural ganglion in foot and ankle. We studied 7cases of intraneural ganglion. We are going to prove the synovial theory by indentifying articular branch of intraneural ganglion. MATERIALS AND METHODS: From August 2003 to May 2011, we evaluated 7 ouf of 8 patients diagnosed as a intraneural ganglion in foot and ankle. The gender ratio were 4 male and 3 female, and the mean age at the time of surgery was 52.9 years. Clinically, we checked pre and post operative symptom, muscle tone and whether loss of muscle tone and sensation exists. We analyzed surgical records and preoperative MRI and compared those with intra-operative finding. RESULTS: In MRI analysis of 7cases, the connection around the joints were confirmed, and 1 case was confirmed in the retrospective analysis of MRI. Intraneural ganglions occurred in medial plantar nerve 3 cases, lateral plantar nerve 1 case, superficial peroneal nerve 1 case and sural nerve 1 case. We could not found recurrence during the follow up periods. Most patients relieved pain after operation, but recovery of sensation was unsatisfactory. We could find some cases pathological finding of the nerve intraoperatively, and clinical result of that cases was poor. CONCLUSION: Intraneural ganglion can occur in various parts in foot and ankle. We concluded that the intranneural ganglion originated from joint by identifying the artichlar branch of ganglion. Due to its small size, it is difficult to find articular branch in operation field. But we do our best to find and remove articular branch. Currently, considering the small amount of research in foot and ankle, more research about articular brach is needed.

The Relationship between the Evaluation of the Graft-bone Interface and the Clinical Results after Double Bundle Anterior Cruciate Ligament Reconstruction

PURPOSE: This study examined the relationship between an evaluation of the graft-bone interface using magnetic resonance (MR) arthrography and the clinical results after double bundle anterior cruciate ligament (ACL) reconstruction. MATERIALS AND METHODS: From December 2005 to October 2007, 15 cases that underwent double bundle ACL reconstruction and that were evaluated by MR arthrography were reviewed. The mean follow-up period was 20 months. The graft-bone interface was assessed by the leakage of contrast medium seen on MR arthrography. Four groups were classified according to the degree of contrast media leakage: no contrast media leakage, the focal type, the crescent type and the circumferential type. A functional evaluation was made using the Lysholm score, the international knee documentation committee (IKDC) score, the difference in the midthigh circumference and the Hop test. The stability was evaluated using a Lachmann test, a pivot shift test, a KT-2000 arthrometer and an anterior drawer stress radiograph using Telos(R) with the knee in 30degrees flexion. RESULTS: Ten cases showed no leakage of contrast media, five cases showed focal leakage and there was no case of crescent and circumferential leakage. The clinical results of the no leakage and focal leakage groups were compared. The functional evaluation such as the Lysholm score, the IKDC score, the difference in the midthigh circumference and the Hop test showed no significant difference between the two groups. The stability evaluation, such as the Lachmann test, the pivot shift test, the KT-2000 arthrometer and anterior drawer stress radiograph, also showed no significant difference. CONCLUSION: On MR arthrography after double bundle ACL reconstruction, adequate osteointegration and satisfactory clinical results could be obtained in the no leakage and focal leakage groups.

Nerve Palsy and Delayed Arterial Occlusion after Total Knee Arthroplasty: A Case Report

Nerve palsy after total knee arthroplasty is a rare complication and this is usually associated with local nerve compression or severe deformity of the knee. In many cases, the cause of nerve palsy was unknown and this is rarely associated with vascular complication. We report here on a case of the patient who had nerve palsy and delayed arterial occlusion after total knee arthroplasty.

Short-term Follow-up Results of Medial Epicondylar Osteotomy for the Varus Knee in TKA

PURPOSE: We wanted to evaluate the results of medial epicondylar osteotomy for the varus knee when performing total knee arthroplasty. MATERIALS AND METHODS: We reviewed 32 cases of medial epicondylar osteotomy for treating varus deformity, and these cases underwent operation from December 2004 to December 2007. The average age of the patients was 71.0-years-old and the average follow-up period was 23.5 months. The clinical outcomes were measured, including the Knee Society score (KSS), the function score (FS) and the range of the motion (ROM). The radiological outcomes were measured by anteroposterior simple radiographs for assessing the union state of the osteotomy site, and the valgus stress radiographs and the whole extremity radiographs were used for assessing the femorotibial angle, the mechanical axis angle and the alignment. RESULTS: The KSS improved from 46.5+/-7.6 to 89.1+/-5.9 points (p<0.001) and the FS increased from 39.5+/-9.2 to 84.2+/-8.5 points (p<0.001). The range of motion increased from 101.5+/-28.2degrees to 116.0+/-10.8degrees (p=0.006). Bony union occurred in 22 knees and fibrous union occurred in 10 knees. The femorotibial angle was corrected from varus 8.2+/-5.0degrees to valgus 5.6+/-1.5degrees (p<0.001) and the mechanical axis angle was revised from varus 13.9+/-4.5degrees to varus 0.7+/-1.6degrees (p<0.001). There were 27 neutral, 4 varus and 1 valgus alignment. On the valgus stress radiographs, the difference compared with the opposite side was 1.0+/-0.6degrees and there was no significant difference between the bony union group and the fibrous union group (p=0.175). CONCLUSION: Medial epicondylar osteotomy for the varus knee when performing total knee arthroplasty could be a useful ligament balancing technique for achieving medial stability of the knee.

Heterotopic Ossification of a Partially Ruptured Achilles Tendon (A Case Report) / 대한족부족관절학회지

Heterotopic ossification of Achilles tendon is known to be related with history of prior Achilles tendon surgery, trauma, Achilles tendon rupture. We report a case of heterotopic ossification of partially ruptured Achilles tendon and treated by surgical removal of ossification and V-Y advancement with tendon repair.

Utility of Preoperative Distractive Stress Radiograph for Beginners to Extent of Medial Release in Total Knee Arthroplasty

BACKGROUND: This study evaluated the preoperative distractive stress radiographs in order to quantify and predict the extent of medial release according to the degree of varus deformity in primary total knee arthroplasty. METHODS: We evaluated 120 varus, osteoarthritic knee joints (75 patients). The association of the angle on the distractive stress radiograph with extent of medial release was analyzed. The extent of medial release was classified into the following 4 groups according to the stage: release of the deep medial collateral ligament (group 1), release of the posterior oblique ligament and/or semimembranous tendon (group 2), release of the posterior capsule (group 3) and release of the superficial medial collateral ligament (group 4). RESULTS: The mean femorotibial angle on the preoperative distractive stress radiograph was valgus 2.4degrees (group 1), valgus 0.8degrees (group 2), varus 2.1degrees (group 3) and varus 2.7degrees (group 4). The extent of medial release increased with increasing degree of varus deformity seen on the preoperative distractive stress radiograph. CONCLUSIONS: The preoperative distractive stress radiograph was useful for predicting the extent of medial release when performing primary total knee arthroplaty.

Recalcitrant Lateral Epicondylitis: Open and Arthroscopic Release / 대한정형외과학회잡지

PURPOSE: To compare clinical outcomes when using open or arthroscopic release for recalcitrantlateral epicondylitis. MATERIALS AND METHODS: A total of 34 cases were followed up for an average of 16 months. Open release was performed in 21, and arthroscopic release in 13. In the open release group, arthroscopic examination was performed first in 7. Intraarticular and extraarticular lesions of the extensor tendon were compared. Pain was evaluated using the Visual Analog Scale, and function was evaluated using the assessment of Nirschl and Pettrone. RESULTS: In arthroscopic findings, 6 out of 20 cases were nearly normal, 6 showed fraying, 4 a linear tear, and 4 avulsion. Some (3 of 5) cases with nearly normal arthroscopic findings had mucinoid degeneration detected during the open procedure. Overall, 86% of open release and 85% of arthroscopic release showed satisfactory results. CONCLUSION: The extraarticular and intraarticular surfaces of the extensor origin had diverse appearances, and both procedures showed satisfactory results. Therefore, arthroscopic release is a useful treatment option for recalcitrant lateral epicondylitis.

A Short Term Follow-up of Anterior Cruciate Ligament Reconstruction using Hamstring Tendon Grafts fixed with Ligament Plate(R)

PURPOSE: To evaluate the clinical outcomes at a minimum of 1 year following the ACL reconstruction with use of Liga- ment Plate(R) which was invented for secure fixation of hamstring tendon graft into femoral tunnel. MATERIALS AND METHODS: Seventy-six patients who could followed up for minimum 12 months were treated with the ACL reconstruction fixed with Ligament Plate(R) using a four-stranded autologous hamstring tendon graft. For femoral fixation, we used Ligament Plate(R), and for tibial fixation, we used suture-post strengthened with cortical screw. Average follow up period was 18.6 months. Prior to surgery and at the follow-up examination, we evaluated the clinical results with Lachmann test, pivot shift test, Lysholm score and the difference of mid-thigh circumference, and KT 2000 arth- rometer was perfomed. For radiographic evaluation, we analyzed knee radiographs including anterior drawer radiographs and evaluated the degree of tunnel enlargement. RESULTS: Lysholm score improved from 61.6 points to 93.8 points. Lachman test revealed negative findings for sixty- three cases, and ten cases with grade 1 laxity and another three cases with grade 2 at last follow-up. Pivot shift test showed negative findings except six cases with grade 1 laxity at last follow-up. The results of KT 2000 arthrometer improved from 5.4mm difference compared with normal limb to 2.1mm respectively. The difference of mid-thigh circumference compared with normal limb showed 1.7cm. Radiographic analysis of anterior drawer view revealed 6.5 mm difference compared with normal limb preoperatively and 1.1 mm difference at last follow-up. Femoral and tibial tunnel enlarged to 2.7mm and 1.8 mm compared with immediate postoperative radiographs. CONCLUSION: ACL reconstruction using hamstring tendon grafts fixed with Ligament Plate(R) could provide sufficient strength of early fixation, and then could show good clinical results. However, long term follow-up was necessary.

The Clinical Relationship between MCL Complete Detachment and Mechanical Alignment in TKA

PURPOSE: To evaluate the clinical relationship between medial collateral ligament(MCL) complete detachment and mechanical alignment in total knee arthroplasty. MATERIALS AND METHODS: From February 2001 to December 2006, we performed 290 TKAs. 9 TKAs(0.03%) happened MCL complete detachment. 1 TKA was excluded for paraplegia. All cases were women. The mean age was 71.1 years old. The mean follow-up period was 41.1 months. There were 7 degenerative osteoarthritis and 1 rheumatoid arthritis. The clinical evaluation included Knee Society Score(KSS), function score and range of motion(ROM) at preoperative, postoperative 3 months, 6 months, 12 months and final follow-up. We measured the femoro-tibial angle and the mecha- nical axis by anterior-posterior and whole lower extremity radiograph. The medial instability obtained serial valgus stress radiograph. RESULTS: There were 4 neutral and 4 varus alignment. KSS, function score, ROM was significantly improved in both group, and there were no significant differences in both group. On serial valgus stress radiograph, the difference compared with normal side decreased from 5.2 degree(postoperative 3 months) to 3.4 degree(final follow-up) in neutral alignment group, from 2.9 degree to 0.9 degree in varus alignment group. In final follow-up, it revealed that the medial instability of varus alignment group was less than that of neutral alignment group. CONCLUSION: In MCL complete detachment, some stability obtained by repair of medial collateral ligament and bracing. Whole instability was not gone. Therefore, we should make the varus alignment of prosthesis in mechanical axis line position of 34 to 67% on the medial tibial plateau.