Biomedical subjects

Yi-Sheng Chan

Publications and source records attributed to Yi-Sheng Chan.

18 recordsLinked to original sources

PubMed2006

Femoral interference screw placement through the tibial tunnel: a novel method without graft damage.

A frequently encountered problem in endoscopic 1-incision anterior cruciate ligament (ACL) reconstruction is the difficulty involved in accurately inserting the femoral interference screw without significant and undesirable divergence between the screw and the graft when a femoral interference screw is fixed through the anteromedial portal. To minimize divergence, the authors demonstrated a modified, easy, and reproducible procedure that can be performed without causing graft injury or requiring special instrumentation. A ligament reconstruction route is created with the use of an ACL guide system. Lead graft sutures are pulled through the anteromedial portal by way of the femoral tunnel and out the anterolateral thigh first. The tendon graft is then inserted through the anteromedial portal and up into the femoral tunnel. A guidewire is introduced through the tibial tunnel into the femoral tunnel. An appropriately sized BioScrew (Linvatec, Largo, FL) is inserted, with the use of a guidewire inside the screw, through the tibial tunnel into the femoral tunnel. The graft is then retrieved through the anteromedial portal and is inserted through the tibial tunnel. Finally, the tendon graft in the tibial tunnel is similarly fixed with a BioScrew of the same size. Moreover, this novel approach is feasible for all tendon grafts (bone-patellar tendon-bone grafts, quadriceps tendon-patellar bone grafts, and hamstring tendon grafts).

Anterior Cruciate Ligament↗

PubMed2006

Arthroscopic evaluation of soft tissue injuries in tibial plateau fractures: retrospective analysis of 98 cases.

PURPOSE: This investigation arthroscopically assesses the frequency of soft tissue injury in tibial plateau fracture according to the severity of fracture patterns. We hypothesized that use of arthroscopy to evaluate soft tissue injury in tibial plateau fractures would reveal a greater number of associated injuries than have previously been reported. METHODS: From March 1996 to December 2003, 98 patients with closed tibial plateau fractures were treated with arthroscopically assisted reduction and osteosynthesis, with precise diagnosis and management of associated soft tissue injuries. Arthroscopic findings for associated soft tissue injuries were recorded, and the relationship between fracture type and soft tissue injury was then analyzed. RESULTS: The frequency of associated soft tissue injury in this series was 71% (70 of 98). The menisci were injured in 57% of subjects (56 in 98), the anterior cruciate ligament (ACL) in 25% (24 of 98), the posterior cruciate ligament (PCL) in 5% (5 of 98), the lateral collateral ligament (LCL) in 3% (3 of 98), the medial collateral ligament (MCL) in 3% (3 of 98), and the peroneal nerve in 1% (1 of 98); none of the 98 patients exhibited injury to the arteries. No significant association was noted between fracture type and incidence of meniscus, PCL, LCL, MCL, artery, and nerve injury. However, significantly higher injury rates for the ACL were observed in type IV and VI fractures. CONCLUSIONS: Soft tissue injury was associated with all types of tibial plateau fracture. Menisci (peripheral tear) and ACL (bony avulsion) were the most commonly injured sites. A variety of soft tissue injuries are common with tibial plateau fracture; these can be diagnosed with the use of an arthroscope. LEVEL OF EVIDENCE: Level III, diagnostic study.

Adult↗

PubMed2006

Arthroscopic reconstruction of the posterior cruciate ligament with use of a quadruple hamstring tendon graft with 3- to 5-year follow-up.

PURPOSE: This study prospectively evaluated 20 patients treated consecutively to determine patient outcomes, efficacy, and complication potential of arthroscopically assisted posterior cruciate ligament (PCL) reconstruction performed with hamstring tendon grafts. METHODS: Twenty patients (15 men and 5 women), each with an isolated PCL injury, underwent PCL reconstruction with hamstring tendon autograft and were enrolled in this prospective study. Average age at time of surgery was 29 years (range, 20 to 57 years). Average time from injury to surgery was 4 months (range, 3 to 12 months). Average follow-up period was 40 months (range, 36 to 50 months). Patients underwent regular follow-up after clinical and radiographic preoperative and postoperative evaluation. Follow-up examinations comprised the Lysholm Knee Score, the Tegner Activity Score, the International Knee Documentation Committee (IKDC) score, thigh muscle assessment, and radiographic evaluation. RESULTS: Mean preoperative Lysholm score for 20 knees was 63 +/- 10 (range, 48-73); mean postoperative Lysholm score was 93 +/- 9 (range, 77-100). Eighteen of 20 patients (90%) showed good or excellent results at final assessment. Mean preinjury and preoperative Tegner scores were 7 +/- 1.5 (range, 5-9) and 3 +/- 1.9 (range, 2-5), respectively; mean postoperative Tegner score for 20 knees was 6.3 +/- 2.4 (range, 4-9). In final IKDC ratings, 85% of patients (17 of 20) were assessed as normal or near normal (grade A or B). A statistically significant improvement was seen in thigh girth difference, extensor strength ratio, and flexor strength ratio before and after reconstruction at a minimum of 3 years of follow-up. CONCLUSIONS: After follow-up for longer than 36 months, analytical results showed satisfactory function after PCL reconstruction with the use of hamstring tendon autografts. We suggest that the hamstring tendon autograft is a safe, effective, and acceptable choice for PCL reconstruction, and that it affords good ligament reconstruction. LEVEL OF EVIDENCE: IV, therapeutic case series.

Adult↗

PubMed2006

Tubular acetabular intraosseous contrast tracking in MR arthrography of the hip: prevalence, clinical significance, and mechanisms of development.

OBJECTIVE: The purpose of this study was to describe tubular intraosseous tracking of contrast medium in the acetabular fossa, to our knowledge a previously undocumented imaging finding in MR arthrography of the hip, and to discuss its prevalence, clinical significance, and possible mechanisms of development. CONCLUSION: Tubular acetabular intraosseous contrast tracking is a common MR arthrographic finding that seems to have little clinical significance. Although the exact pathophysiologic mechanism is unknown, we presume repeated pumping of joint fluid through the nutrient foramina of the acetabular fossa may be one mechanism.

Acetabulum↗

PubMed2005

Evaluating hip labral tears using magnetic resonance arthrography: a prospective study comparing hip arthroscopy and magnetic resonance arthrography diagnosis.

PURPOSE: To evaluate the sensitivity and accuracy of magnetic resonance arthrography (MRA) with true sagittal scout image mapped radial reformation in localizing hip labral tears. TYPE OF STUDY: Case series. METHODS: Thirty patients were examined with hip MRA because of suspected labral tears. Every patient underwent normal hip arthrography and MR examinations using a 1.5-T scanner with a 3D-FLASH pulse sequence. Multiplanar reformation using double oblique technique produced radial reformatted rotation images with 10 degrees increment on the acetabular rim. Labral tears were annotated as anterior-superior (AS), anterior-inferior (AI), posterior-superior (PS), and posterior-inferior (PI) quadrant based on the cranial-caudal axis in true sagittal reformatted scout localizing image. Patients with positive MRA findings were counseled to have the arthroscopic hip procedure. RESULTS: Five patients showed no MRA indication of labral tear. Of 25 patients who had MRA evidence of labral tear, 17 underwent arthroscopic hip surgery. One patient had only synovial process in the hip joint near the suspected MRA area. The remaining 16 operated patients had labral tears with a total of 21 quadrant lesions on arthroscopy (distributed as AS, 14; AI, 3; PS, 2; and PI, 2). Radial reformatted images revealed accurate mapping with arthroscopic findings in 21 of the 22 quadrant lesions. The sensitivity and accuracy of MRA for the diagnosis of hip labral tear were 100% and 94%, respectively, and the sensitivity and accuracy of radial reformatted MRA for mapping the tear location were 100% and 96%, respectively. CONCLUSIONS: MRA using radial reformatted images with a true sagittal localizer may achieve superior success rates in diagnosing hip labral lesions and in guiding the arthroscopist in portal selection, thus rendering location of hip labral tears simpler in surgery. It supplied detailed preoperative information to the surgeon, avoiding unnecessary surgery for patients if the diagnosis was unconfirmed. LEVEL OF EVIDENCE: Level III.

Acetabulum↗

PubMed2005

Arthroscopic suture repair of peripheral tears of triangular fibrocartilage complex using a volar portal.

Surgical repair of a Palmer type IB triangular fibrocartilage complex (TFCC) tear can be difficult using conventional dorsal portals and it may need special repair kits. The authors describe an arthroscopic technique using an additional volar portal that allows quick access and a secure purchase of peripheral TFCC tears as well as a distinct approach to dorsal wrist structures.

Arthroscopy↗

PubMed2005

Posterior cruciate ligament reconstruction using hamstring tendon graft with remnant augmentation.

Despite good early functional results, the posterior laxity of the knee is not completely eliminated after posterior cruciate ligament (PCL) reconstruction. The PCL can retain the normal tension only when the injured ligament is maintained anatomically. This article describes a technique of PCL reconstruction using hamstring tendon graft with PCL remnant augmentation. The harvested hamstring tendons were quadrupled, sized, and pretensioned before use. The PCL remnants and the synovium were preserved. Minimal debridement was performed to gain access to the insertion sites. The tibia and femoral tunnels were created with graft size-matched reamers. The graft was transfixed at 70 degrees of knee flexion with a 15-lb anterior drawer force on the proximal tibia. This surgical technique has several advantages. The hamstring graft acts as an independent PCL reconstruction and maintains the PCL remnant tension. The PCL remnants and synovium may be beneficial to ligament healing and postoperative rehabilitation. The procedure is technically feasible and cosmetically acceptable. The selection of autograft precludes the risks of allograft and artificial ligament. The short-term results are encouraging, but long-term results are needed to confirm the value of this technique for PCL reconstruction.

Arthroscopy↗

PubMed2005

The use of suramin, an antifibrotic agent, to improve muscle recovery after strain injury.

BACKGROUND: Muscle strain injuries are extremely common in sports medicine. Muscle healing often is hindered by scar tissue formation after injury. HYPOTHESIS: Suramin can prevent scar tissue formation and improve muscle healing after injury because of its ability to antagonize transforming growth factor-beta1, a fibrotic cytokine. STUDY DESIGN: Controlled laboratory study. MATERIALS AND METHODS: In vitro, muscle-derived fibroblasts (a potential cell source of muscle fibrosis) were incubated with suramin and/or transforming growth factor-beta1; a cell growth curve was obtained. In vivo, mouse gastrocnemius muscles were strain injured. Suramin or sham/control intramuscular injections were performed after injury at various time points. Mice were sacrificed at various time points after injury, and skeletal muscle tissue was evaluated by using histological and physiological tests. Statistical analysis was performed by using analysis of variance and Fisher tests. RESULTS: Suramin decreased the stimulating effect of transforming growth factor-beta1 on the growth of muscle-derived fibroblasts in vitro. Significantly less fibrous scar formation was observed in suramin-treated muscles than in sham-injected muscles. The fast-twitch and tetanus strength of suramin-treated muscles was also significantly greater relative to that of control muscles. CONCLUSIONS: Suramin blocked the stimulatory effect of transforming growth factor-beta1 on muscle-derived fibroblasts in vitro. Suramin also reduced fibrous scar formation in muscle and enhanced muscle strength in strain-injured skeletal muscle. CLINICAL RELEVANCE: These results may facilitate the development of strategies to enhance muscle healing after injury.

Animals↗

PubMed2004

Factors affecting the outcome of distal realignment for patellofemoral disorders of the knee.

This study correlated the risk factors with the clinical outcome of distal realignment for patellofemoral disorders in 48 patients with 53 knees with 25 to 96 months follow-up. The indications for surgery included pain and disability due to patellofemoral disorders with failure of at least 6 months of conservative treatments. The evaluations included pain scores, Lysholm functional scores and radiographs of the knee. The overall results were satisfactory in 47 knees (88.7%) and unsatisfactory in six knees (11.3%). There was no correlation of the clinical results with age, sex, body weight and body height, preoperative pain scores and Lysholm scores. However, the clinical outcome correlated with the severity of articular damage and the correction of patellar malalignment. Error in patient selection and inadequate surgical technique were attributable to poor outcomes.

Adolescent↗

PubMed2004

Arthroscopic single- versus double-bundle posterior cruciate ligament reconstructions using hamstring autograft.

This prospective study compared the clinical results of single- and double-bundle posterior cruciate ligament (PCL) reconstruction with a minimum follow-up of 2 years. There were 35 patients including 19 single- and 16 double-bundle posterior cruciate ligament reconstructions using hamstring autograft. The average age was 29.4 +/- 13.6 years versus 28.2 +/- 10.4 years; and the average follow-up was 41.0 +/- 13.1 months versus 28.1 +/- 4.2 months for single- and double-bundle reconstruction, respectively. The indication for surgery was functional disability of the knee due to pain and instability as the result of high-energy PCL injury. The evaluation parameters included functional assessment, ligament laxity, functional score and radiographs of the knee. The results showed no significant difference in functional assessment, ligament laxity, functional score and radiographic changes of the knee between the two techniques. The rate of overall satisfaction with the operation was comparable from patient and surgeon perspectives. Contrary to many recent reports, the results of this study showed that single- and double-bundle PCL reconstruction using hamstring autograft produced comparable clinical results in medium-term follow-up. The difference between single- and double-bundle PCL reconstruction, if any, can be concluded only with long-term results and larger number of patients.

Adolescent↗

PubMed2004

Comparison of autogenous and allogenous posterior cruciate ligament reconstructions of the knee.

This prospective clinical study was performed to compare the functional results and clinical outcomes of 32 autogenous and 23 allogenous posterior cruciate ligament (PCL) reconstructions with an average follow-up of 34 months. Both groups showed similar age, gender and follow-up time. The indications for surgery included knees with functional disability due to pain and instability from high-energy PCL injury with failure of conservative treatments. Arthroscopic single-bundle PCL reconstruction was performed with a similar technique in both groups with the exception of graft selection. All patients received the same postoperative rehabilitation. The evaluation parameters included functional assessment, ligament laxity, functional score, kinematics evaluation and radiographic examination. Autogenous and allogenous PCL reconstructions showed comparable functional results and clinical outcomes. No statistically significant difference was noted in ligament laxity and radiographic changes between the two groups. Complications were more prevalent with autogenous grafts. In conclusion, autogenous and allogenous tendon grafts are equally effective in PCL reconstruction.

Adolescent↗

PubMed2004

Opening-wedge osteotomy, allografting with dual buttress plate fixation for severe genu recurvatum caused by partial growth arrest of the proximal tibial physis: a case report.

Injuries to the proximal tibial physis are among the least common epiphyseal injuries. We present a case of severe genu recurvatum deformity (45 degrees) with leg length discrepancy (4 cm) following a neglected proximal tibial physeal injury incurred 6 years previously. The 16-year-old patient was successfully treated by open-wedge osteotomy, allograft reconstruction, and dual buttress plate fixation. At 3 years' follow-up, the patient was asymptomatic, fully active with a full range of motion (0 - 140 degrees) of the leg, and equal leg lengths. There were no signs of genu recurvatum clinically.

Adolescent↗

PubMed2003

Antifibrotic effects of suramin in injured skeletal muscle after laceration.

Muscle injuries are very common in traumatology and sports medicine. Although muscle tissue can regenerate postinjury, the healing process is slow and often incomplete; complete recovery after skeletal muscle injury is hindered by fibrosis. Our studies have shown that decreased fibrosis could improve muscle healing. Suramin has been found to inhibit transforming growth factor (TGF)-beta1 expression by competitively binding to the growth factor receptor. We conducted a series of tests to determine the antifibrotic effects of suramin on muscle laceration injuries. Our results demonstrate that suramin (50 microg/ml) can effectively decrease fibroblast proliferation and fibrotic-protein expression (alpha-smooth muscle actin) in vitro. In vivo, direct injection of suramin (2.5 mg) into injured murine muscle resulted in effective inhibition of muscle fibrosis and enhanced muscle regeneration, which led to efficient functional muscle recovery. These results support our hypothesis that prevention of fibrosis could enhance muscle regeneration, thereby facilitating more efficient muscle healing. This study could significantly contribute to the development of strategies to promote efficient muscle healing and functional recovery.

3T3 Cells↗

PubMed2003

Arthroscopic-assisted reduction with bilateral buttress plate fixation of complex tibial plateau fractures.

PURPOSE: Our aim was to determine the outcome of arthroscopic-assisted reduction with bilateral buttress plate fixation for the treatment of closed complex tibial plateau fractures. TYPE OF STUDY: Case series. METHODS: 18 consecutive patients (12 men, 6 women) with complex tibial plateau fractures were enrolled in this prospective study. All patients underwent arthroscopic-assisted bilateral buttress plate fixation of closed complex tibial plateau fractures. The average age at operation was 35 years (range, 23 to 45 years). The follow-up period ranged from 39 to 69 months, with an average of 48 months. Using the Schatzker classification, there were 11 type V and 7 type VI fractures. The clinical and radiological outcomes were determined according to Rasmussen's system. RESULTS: All of the 18 fractures united. Overall, 4 (22%) patients were rated as excellent, 12 (67%) good, and 2 (11%) fair. Secondary osteoarthritis appeared in 3 injured knees (16.7%). One patient had a wound dehiscence (3 cm long) of the medial incision. Condylar joint surface depression was noted in 3 patients without functional instability. Two patients had valgus alignment between 10 degrees and 15 degrees. Two patients had the paresthesia over the lateral calf. There were no complications directly associated with arthroscopy in any of the 18 patients. No deep vein thrombosis, infection, or knee stiffness was found at final follow-up. CONCLUSIONS: Arthroscopic-assisted reduction with bilateral buttress plate fixation for complex tibial plateau fractures allows accurate fracture reduction, diagnosis, and treatment of associated intra-articular lesions, and less dissection than open reduction internal fixation.

Adult↗

PubMed2003

Reducing the "killer turn" in posterior cruciate ligament reconstruction.

PURPOSE: Graft abrasion caused by sharp graft angulation at the graft-tunnel margin of the proximal tibia (the "killer turn") may cause graft failure after posterior cruciate ligament (PCL) reconstruction using the traditional anteromedial route tibial tunnel. One method to reduce the graft angulation is to use the anterolateral route tibial tunnel. However, less acute graft angulation may increase joint translation because of a decrease in graft compressive force. The purpose of this study was to compare the graft angulation and joint translation between anteromedial and anterolateral route tibial tunnels. TYPE OF STUDY: Biomechanical study. METHODS: Twelve above-the-knee amputation specimens were used in this study. Anteromedial and anterolateral tibial tunnels were made at the desired locations, and the same femoral tunnel was used. Graft angulation was measured by inserting a malleable pin into the tibial and femoral tunnels. Measurements of graft angulation were performed with the knee in extension and in 90 degrees of flexion. The joint translation was measured by the posterior translation of the tibia on the femur at 90 degrees of flexion with a 15-lb posterior force applied to the anterior proximal tibia after PCL reconstruction through the respective tunnels. RESULTS: The difference in graft angulation between anterolateral and anteromedial route tibial tunnels was statistically significant (P <.001); however, the difference in joint translation showed no statistical significance between the 2 tunnel routes. CONCLUSIONS: The anterolateral route tibial tunnel significantly reduced the sharp graft angulation ("killer turn") at the graft tunnel margin of the proximal tibia, but it did not increase the joint translation as compared with the traditional anteromedial route tibial tunnel. The anterolateral route tibial tunnel is thought to be a better choice when arthroscopic PCL reconstruction is performed with the tunnel technique.

Aged↗

PubMed2003

Arthroscopically assisted osteosynthesis for tibial plateau fractures.

BACKGROUND: Options for management of tibial plateau fracture are numerous, and the outcome depends on several factors. With the inherent advantages of arthroscopy, the results of tibial plateau fracture have been greatly improved. METHODS: Thirty-one patients were treated with arthroscopically assisted reduction for tibial plateau fracture, with an average follow-up period of 3 years. Evaluations were performed with the Hospital for Special Surgery knee score clinically, and with the Ahlbäck scale for osteoarthritis radiographically. RESULTS: Eighty percent of cases were Schatzker type II, III, or IV, and over half (52%) of the patients had concomitant intra-articular lesions. Twenty-nine patients (93.5%) had satisfactory results according to the Hospital for Special Surgery knee score, and only one patient developed degenerative arthritis during the period of follow-up. CONCLUSION: The arthroscopically assisted reduction of tibial plateau fracture is a safe and promising procedure. The results are comparable to traditional methods of open reduction.

Adult↗

PubMed2002

Arthroscopically assisted osteosynthesis of complex intra-articular fractures of the distal radius.

BACKGROUND: Complex intra-articular fractures of the distal radius pose a great challenge in orthopedic surgery. Conventional open reduction and internal fixation generally yields poor functional outcome. The technique of arthroscope-assisted surgery allows more accurate reduction of the articular surface and treatment of soft tissue lesions, both of which are necessary for regaining anatomic structure and satisfactory function. METHODS: Twenty wrists in 18 patients with intra-articular fracture of the distal radius received arthroscopic surgery and percutaneous pinning with or without external skeletal fixation and bone grafting. A new traction method was designed that allows arthroscopic surgery and fluoroscopic monitoring to be performed simultaneously. Postoperative follow-up averaged 24.7 months. RESULTS: All except one of these patients returned to work within 3 to 6 months after surgery. Later collapse with minimal articular step-off was noted on radiographs before osseous union in two patients who did not undergo bone grafting. Decreased radial height because of subsequent displacement at the metaphyseal fracture was noted in one patient who did not receive external skeletal fixation initially. CONCLUSION: The technique of arthroscope-assisted surgery, despite a steep learning curve, is an invaluable method. Results using this technique are promising and few complications are encountered in the treatment of complex radius platform fractures. The bone grafting procedure augments osseous union, shortens the duration of external skeletal fixation, and thus lessens joint stiffness.

Adult↗

PubMedDate not supplied

Complications of hip arthroscopy: analysis of seventy three cases.

BACKGROUND: Hip arthroscopy is recognized as a highly effective means of treating joint disorders. Complications in hip arthroscopy, including neurovascular traction injury, compression injury to the perineum and scope trauma, have been reported. We report our experience with 73 hip arthroscopy procedures and complications at Chang Gung Memorial Hospital. METHODS: Seventy-two patients with 73 hips with severe hip pain were enrolled in this prospective study. The average age of the patients was 42 years (range, 22-61 years). The average follow-up period was 16 months (range, 12-36 months). Surgical indications for hip arthroscopy were labral tears (54 cases, 73.9%); painful dysplastic hips (7 cases, 9.5%); osteoarthritis (5 cases, 6.8%); synovitis (3 cases, 4.1%); ligament teres tears (2 cases, 2.8%); chondromatosis (1 case, 1.4%); and avascular necrosis of the femoral head (1 case, 1.4%). With the patient in the supine position with the involved leg in traction, 2 or 3 portals (anterior, anterolateral or posterolateral) were made. Intraoperative and postoperative arthroscopic complications were recorded and prospectively analyzed. RESULTS: The average operative time was 67 minutes (range, 30-190 minutes) and the average traction time was 58 minutes (range, 30-150 minutes). During surgery, 12 of 73 (16.4%) patients had mild scope trauma to the femoral head, which did not affect their excellent outcomes. Five (7%) patients had transient sciatic nerve neuropraxia and achieved complete recovery within 2 weeks after surgery. CONCLUSION: No major complications of hip arthroscopy were noted in this series. The most frequent complication was mild scope trauma to the femoral head. With experience in the technique and good hip arthroscopic instrumentation, hip arthroscopy complications can be minimized. We suggest that hip arthroscopy is a safe technique, providing an additional valuable tool for hip surgery.

Adult↗