Sang Gwon Cho

Comparison of functional results with navigation-assisted minimally invasive and conventional techniques in bilateral total knee arthroplasty.

This study was undertaken to compare the clinical and radiological results achieved using navigation-assisted minimally invasive surgery (NA-MIS) and conventional (CON) techniques in 42 bilateral total knee arthroplasty (TKA) patients with a minimum follow-up of one year. Clinical evaluations were performed using range of motion (ROM), Hospital for Special Surgery (HSS) scores, and Western Ontario and McMaster University (WOMAC) scores (pain, functional, and total) at 3, 6 and 9 months and one year postoperatively. Patients’ subjective preferences and radiological indices, including mechanical axis and coronal inclinations of the prostheses, were compared at one year postoperatively. NA-MIS TKA yielded better HSS and WOMAC total scores than CON TKA up to six months, and a better WOMAC pain score up to 9 months. However, these differences were not significant at one year postoperatively. ROM was comparable in both groups at all times, but more patients preferred the NA-MIS side to the CON side. Radiological results showed no differences in mean values between the two surgical groups, although the NA-MIS group contained fewer outliers than the CON group. In conclusion, NA-MIS TKA was associated with better clinical results up to 6 or 9 months after surgery, giving more accurate leg alignment than CON TKA.

Two-stage reconstruction of infected hip joints.

Two-stage reconstruction using an antibiotic-loaded cement spacer is the preferred treatment of deep infection after total hip arthroplasty (THA). We evaluated the results of this technique for the treatment of primary hip infections. Nine consecutive patients with infected hip joints were treated using this technique. The average duration of follow-up was 42 months. Debridement and insertion of an antibiotic-loaded cement spacer was performed in the first stage. After eradication of infection, it was converted to THA in the second stage. Of the 9 hips, 8 were successfully converted to THA after an average of 23 weeks. One patient required spacer reinsertion, and another experienced reinfection after THA. Average Harris hip score improved from 38.37 before surgery to 57.62 between the 2 stages to 97.83 at final follow-up. Two-stage reconstruction using an antibiotic-loaded cement spacer was found to give satisfactory results for the treatment of hip infections with various etiologies.

Tibial plateau stress fracture after unicondylar knee arthroplasty using a navigation system: two case reports

Satisfactory alignments of components in total knee arthroplasty have been reported since the introduction of navigation systems. And thus, such techniques have been introduced for minimally invasive unicondylar knee arthroplasty (UKA). Several intraoperative fractures of the tibial plateau have been reported in association with minimally invasive UKA and some stress fractures of tibial plateau associated with design of instrument have been reported. Here, we report on two cases of stress fracture of the tibial medial plateau after minimally invasive UKA was performed using a navigation system.

Mevinolin enhances osteogenic genes (ALP, type I collagen and osteocalcin), CD44, CD47 and CD51 expression during osteogenic differentiation

AIMS In this study, we evaluated the effect of mevinolin on the expressions of osteogenic genes and surface molecules expression during osteogenesis. MAIN METHODS D1 cells were cultured in osteogenic differentiation medium (ODM) for 6 days, treated with mevinolin for 2 days, and then subjected to alizarin red S staining, MTT assays, alkaline phosphatase (ALP) activity determinations, energy dispersive X-ray spectrophotometry (EDX), real-time PCR, Western blot, fluorescence microscopy and FACS analysis. KEY FINDINGS Mevinolin is commonly prescribed and widely used to lower cholesterol levels, and offers an important, effective approach to the treatment of hypercholesterolemia and arteriosclerosis. However, the direct effect of mevinolin on osteogenesis in vitro has not been clarified. ODM has been previously shown to increase the osteoblast differentiation of D1 cells. In the present study, we investigated the expressions of osteogenic genes and surface molecules during osteoblast differentiation induced by mevinolin. We found that the induction of ALP, type I collagen, osteocalcin, CD44, CD47 and CD51 by mevinolin is responsible for the osteoblastic differentiation of D1 cells. SIGNIFICANCE Our data show that mevinolin enhances the expressions of proteins and surface molecules related to osteogenesis.

Outcome of Achilles Tendon Ruptures Treated by a Limited Open Technique

Background: The optimal surgical management of Achilles tendon ruptures remains a topic of active debate. Recently, many authors have preferred the limited open method because it afforded sufficient visualization to ensure anatomic apposition of disrupted tendon fibers, minimized local blood supply disturbances, guaranteed free tendon movement, and produced excellent cosmesis. We report our initial experience with this technique and review the literature. Materials and Methods: The outcomes of 30 consecutive patients that underwent limited open repair for Achilles tendon rupture using Achillon® (Newdeal SA, Lyon, France) from June 2003 to May 2006 were retrospectively reviewed. There were 20 men and 10 women, of average age 38.6 years, and the average followup period was 18.5 months. Twenty of the injuries were sports-related, eight were caused by a fall, and two by a laceration. The clinical results were assessed using patient satisfaction, the ankle-hindfoot scale of the American Orthopaedic Foot and Ankle Society (AOFAS), and the occurrence of complications. Results: At last followup, sixteen patients were very satisfied, 11 were satisfied, and the remaining three were dissatisfied. Mean patient AOFAS score was 93.0 points. Surgical complications noted were re-rupture in two cases, deep infection in one, and sural nerve injury in one. All patients except the three patients with a re-rupture or infection, returned to work 2 months postoperatively and resumed light exercise at 3 months, and previous sporting activities by 6 months. Conclusion: The described limited open repair technique for Achilles tendon ruptures provided excellent cosmetic results, satisfactory functional results, and a high level of patient satisfaction. Level of Evidence: Level III, therapeutic study.

Kinematic study following double-bundle, anterior cruciate ligament reconstruction.

The purpose of this study was to evaluate tibiofemoral kinematics after double-bundle anterior cruciate ligament (ACL) reconstructions and compare them with those of successful single-bundle reconstructions and contralateral normal knees using open MR images. We obtained MR images based on the flexion angle without weight-bearing, from 20 patients with successful unilateral single-bundle (10 patients) and double-bundle (10 patients) ACL reconstructions with tibialis anterior allografts and a minimum 1-year follow-up. The MR images of the contralateral uninjured knees were used as normal controls. Sagittal images of the mid-medial and mid-lateral sections of the tibiofemoral compartments were used to measure the translation of the femoral condyles relative to the tibia. The mean translations of the medial femoral condyles on the tibial plateaus during knee joint motion showed no significant differences among normal, single-bundle, and double-bundle ACL reconstructed knees (all p>0.05). The mean translations of the lateral femoral condyles showed a significant difference between normal and single-bundle reconstructed knees, or between single-bundle and double-bundle reconstructed knees (p<0.05). However, there was no significant difference between normal and double-bundle reconstructed knees (p=0.220). These findings suggest that double-bundle ACL reconstruction restores normal kinematic tibiofemoral motion better than single-bundle reconstruction.RésuméLe but de cette étude était d’évaluer, par les images de résonnance magnétique, la cinématique tibio-fémorale après reconstruction du ligament croisé antérieur par double tunnel et de la comparer avec celle obtenue après réussite des reconstructions à un seul tunnel et celle du genou normal controlatéral. Nous avons étudié des images basées sur l’angle de flexion en décharge chez 20 patients après reconstruction par allogreffe tibiale antérieure suivis au moins un an : 10 avec succés de la reconstruction par un seul tunnel et 10 avec reconstruction par un double tunnel. Les images du genou controlatéral non traumatisé servaient de contrôle. Des images sagittales de la partie moyenne des compartiments fémoro-tibiaux permettaient la mesure de la translation des condyles fémoraux par rapport au tibia. La translation du condyle interne pendant la flexion du genou n’était pas différente entre le genou normal et la reconstruction par simple ou double tunnel (p>0,05). La translation du condyle externe était significativement différente entre le genou normal et la reconstruction par simple tunnel et entre les reconstructions par simple et double tunnel (p<0,05). Cependant il n’y avait pas de différence entre le genou normal et la reconstruction par double tunnel (p=0,220). Ces résultats suggèrent que la reconstruction du croisé antérieur par double tunnel restore mieux la cinématique du genou que la reconstruction par simple tunnel.

Total Ankle Arthroplasty following Revascularization of Avascular Necrosis of the Talar Body: Two Case Reports and Literature Review

Total ankle arthroplasty (TAA) has emerged as another solution to ankle arthritis, as it provides reliable pain relief, preserves motion, and facilitates recovery as compared with fusion. However, the use of cementless TAA to treat ankle osteoarthritis with avascular necrosis (AVN) of the talar body is contraindicated because the potential for good ingrowth and component fixation is low.2,3,9,10 The authors describe two cases of end-stage ankle arthritis combined with AVN of the talar body, in which cementless TAA was performed to preserve ankle mobility because magnetic resonance (MR) images and radionuclide bone scanning showed revascularization of the talus.

Displaced Stress Fracture of the Femoral Neck Treated by Valgus Subtrochanteric Osteotomy 2 Case Studies

it was once thought to be. Since it was first reported in 1936, several authors have subsequently reported series of femoral neck stress fractures. Stress fracture of the femoral neck is commonly seen in military recruits and long-distance marathon runners. In most instances, these fractures are nondisplaced, respond well to conservative treatment, and are associated with minimal morbidity. Moreover, most authors have concluded that these fractures should be detected early before displacement occurs, because displaced SFFN carries a high risk of complications such as nonunion, delayed union, and avascular necrosis of the femoral head. Treatment outcome depends on reduction alignment, time between fracture occurrence and treatment, and the type of implant used. Various techniques, including muscle pedicle bone grafting and fibula grafting, have been described for the treatment of displaced SFFN and its complications. However, to the best of our knowledge, the use of subtrochanteric valgus osteotomy for the primary treatment of displaced SFFN has not been reported. Here, we describe 2 cases of displaced SFFN with delayed presentation that were successfully treated by subtrochanteric valgus osteotomy. CASE 1

A Modified Transtrochanteric Rotational Osteotomy for Osteonecrosis of the Femoral Head

The aim of this study is to report the clinical results of modified transtrochanteric osteotomy in osteonecrosis of the femoral head. The authors used a modified transtrochanteric osteotomy for rotational osteotomy in which the greater trochanter is not detached. In 82 cases (75 patients), the mean age was 33 years; 14 were classified as Ficat stage 2, 55 as stage 3, and 13 as Ficat stage 4. We performed simple modified rotational osteotomy in 16 cases, a combination of osteotomy and simple bone grafting in 7, and a combination of osteotomy and muscle pedicle bone grafting in 59 cases. Postoperative evaluation utilized radiographic findings and the Harris hip score. Five patients underwent total hip arthroplasty. Among the 77 surviving cases, excellent results were obtained in 47 hips, good in 22, fair in 5, and poor in 3. Including 3 cases that were classed as poor, overall survival rate was 90%. Using modified transtrochanteric rotational osteotomy, we were able to obtain satisfactory results. Although this technique is difficult to perform, it is recommended particularly for young patients with stage 2 or 3 and some selected patients with stage 4.