Comparison of Radiologic Measurements of Total Knee Replacement using Computer-assisted Navigation System and Conventional System in Varus Deformity of the Knee / 대한정형외과학회잡지

PURPOSE: To compare the radiologic measurements of the mechanical axis and the implant position of Total Knee Arthroplasty (TKA) using a computer-assisted navigation system with those using conventional TKA in varus deformity. MATERIALS AND METHODS: From January 2004 to January 2005, 49 TKAs using a CT-free navigation system (Vector Vision(R), BrainLab, Heirnstetten, Germany) (Group I) and 24 TKAs using the conventional technique (Group II) were performed on patients who had a preoperative varus deformity>10degrees. The patients were also subdivided into two groups, patients with a varus deformity 20degrees (group B). The PFC Sigma implants were used in both groups. The mechanical axis and implant position were measured by 2 observers according to the reontgenographic evaluation system of the American Knee Society. RESULTS: There was no significant difference in alpha, beta, delta angle and mechanical axis between group I and II. There was a significant difference in the gamma angle between group I and II (p20degrees tended to have more postoperative varus mechanical alignment than those with a preoperative varus deformity between 10degrees and 20degrees after TKA. More careful attention during the registration of the femoral mechanical axis should be paid in patients with a larger varus deformity in TKA using a computer-assisted navigation system. On the other hand, a reasonable mechanical valgus angle should be considered in femoral bone cutting for a varus deformity of the distal femur in conventional TKA. In addition, inadequate positioning of intramedullary rod should be recognized in conventional TKA.

Cruciate Retaining Medial Pivot Knee / 대한정형외과학회잡지

Purpose: To analyze the clinical and radiographic results of patients who underwent total knee arthroplasty with a posterior cruciate retaining medial pivot knee, and to identify the technical aspects in preserving the posterior cruciate ligament. Materials and Methods: From March 2002 to Dec 2003, 40 total knee arthroplasties with a cruciate retaining medial pivot knee were implanted in 28 cases. The average follow-up period was 2.8 years (range, 2 to 3.7 years). The clinical and radiographic results were evaluated using the clinical and roentgenographic evaluation and scoring system of the American Knee Society. Results: The average flexion contracture before surgery was 5.4degrees, which improved to 0.6degrees at the last follow-up. The average preoperative knee flexion was 126.1degrees and 126.6degrees at the last follow-up. The average knee score improved from 60 points preoperatively to 94.8 points postoperatively, and the average functional score improved from 55.3 points to 87.0 points at the final evaluation. The average post operative alpha, beta, gamma and delta angles were 95.1degrees, 91.1degrees, 3.6degrees and 84.0degrees, respectively. There were no postoperative complications. Conclusion: The short term clinical results in patients who had undergone total knee arthroplasty with a cruciate retaining medial pivot knee was acceptable.

Efficacy of Computer Assisted Surgery in Revision Total Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to analyze the accuracy of the mechanical axis and implant positions postoperatively and to evaluate the radiology results of computer assisted navigation surgery for bone cutting and ligament balancing in revision TKA. MATERIALS AND METHODS: 13 consecutive revision TKAs were performed by a single surgeon with use of computer assisted surgery (CAS) from July 2004 to August 2005. At the revision, the mean age was 64.7 years. The mean interval from the index arthroplasty was 9.8 years. The cause of the revision included 11 cases of polyethylene wear and 2 cases of loosening. Two observers measured the mechanical axis, position of the implants, and level of joint lines. RESULTS: By observer I, the mechanical axis improved from varus 11.9degrees to valgus 1.5degrees, and the mean alpha, bets, gamma and delta angles were 95.3, 90.8, 3.9 and 87.6degrees respectively. From observer II, the mechanical axis improved from varus 11.6degrees to valgus 1.6degrees, and mean alpha, beta, gamma and delta angles were 95.5, 90.5, 4.1 and 87.9degrees respectively. The measured angles from observers I and II showed a good correlation. CONCLUSION: Accurate bone cutting and verification in each step are possible using real time information provided by the CAS. The mechanical axis, component positions, joint line could be checked and adjusted with feedback of navigation system. Information about flexion and extension gap and ligament balancing could be verified during revision surgery.

Structural Allograft for Management of Severe Bone Defectin Revision Total Knee Arthroplasty / 대한정형외과학회잡지

PURPOSE: To analyze the clinical and radiographic results after revision total knee arthroplasty using a structural allograft for large bone defects. MATERIALS AND METHODS: 184 cases of revision total knee arthroplasty were performed from January 1992 to February 2003. Among them, 52 knees in 48 patients with the use of structural allograft for the management of large bone defects were retrospectively reviewed. Those 52 knees have been followed until recently. The average follow-up period was 5 years and 6 months. Fresh-frozen femoral head was used as the structural allograft in all knees. The clinical rating system of the American Knee Society was used for the clinical assessment. Union at the allograft-host bone junction, femoro-tibial angle and periprosthetic radiolucent lines using a radiographic evaluation of American Knee Society were analyzed radiographically. RESULTS: At the final follow-up, the mean preoperative knee and function score improved from 38.6 points to 82.6 and 30.3 to 76.4, respectively. Radiographically, union of the allograft to the host bone was observed in all knees. The average femoro-tibial angle was corrected from 1.8 degrees in valgus to 6.2 degrees. The radiographic evaluation revealed no evidence of loosening. CONCLUSION: Revision total knee arthroplasty using a femoral head allograft is an appropriate surgical method for treating large bone defects.

Intraoperative versus Postoperative Measurement in Total Knee Arthroplasty using Computer-Assisted Orthopaedic Surgery (CAOS): Accuracy of CAOS / 대한정형외과학회잡지

PURPOSE: The purpose of this research was to compare the intra-operative and post-operative measured angle in total knee arthroplasty (TKA) and to evaluate the postoperative improvement in the mechanical axis. MATERIALS AND METHODS: Forty TKAs were performed using CAOS between February and May 2004. We measured the mechanical axis in the preoperative orthograms. After inserting the implant, we measured the femoral component angle (FCA), tibial component angle (TCA) and tibial component slope (TCS) using the verification tool in CAOS, on the post-operative orthogram and X-ray of the lateral tibial view, 2 observers measured the FCA, TCA, TCS and mechanical axis. RESULTS: The mean FCA, TCA and TCS using the verification tool in CAOS, were valgus 0.03+/-0.85degrees, valgus 0.49+/-1.02degrees, nd 4.26+/-1.64degrees. The mean FCA, TCA and TCS by observer 1 were valgus 0.67+/-1.24degrees, varus 0.54+/-1.54degrees, and 4.57+/-1.74degrees and those by observer 2 were valgus 0.48+/-1.17degrees, varus 0.52+/-1.44degrees, and 4.24+/-2.83degrees. There was a positive correlation between the measured angle by respective observers and the angle measured by the CAOS (p<0.05). The mechanical axis by observers 1 and 2 improved from varus 13.96degrees to valgus 0.04degrees and from varus 14.12degrees to valgus 0.08degrees respectively. CONCLUSION: CAOS affords the possibility of precisely placing the femoral and tibial components. The angles measured by the respective observers and in the CAOS were significantly correlated.

Comparative Analysis of Radiologic Measurement According to TKR using Computer Assisted Surgery and Conventional TKR / 대한정형외과학회잡지

PURPOSE: To compare radiologic measurements of femoral and tibial component position in the total knee replacement (TKR) using computer-assisted surgery (CAS) with those of conventional TKR. MATERIALS AND METHODS: Two groups of 40 TKRs each were operated on using a CT-free navigation system or the conventional technique. Patients in both groups were matched according to age, gender, diagnosis, prosthesis and PCL retaining or substitution. We measured femoral component frontal (alpha angle) and sagittal angle (gamma angle), tibial component frontal (beta angle) and sagittal angle (delta angle). We also studied whether femoral notch was present or not. RESULTS: There were no significant differences in alpha angle, beta angle, delta angle and femoral notch between CAS and conventional TKR (p>0.05). The mean delta angle in the group of TKRs using CAS was 0.28+/-1.96 degrees, and in the group of conventional TKRs was 2.39+/-2.73degrees(p<0.0001). This difference was statistically significance. CONCLUSION: Our study has shown that there were no significant differences in alpha angle, beta angle, delta angle and incidence of femoral notching between CAS TKR and conventional TKR. Gamma angle was different statistically between CAS TKR and conventional TKR. The CAS afforded to precisely place femoral component in sagittal plan than conventional method.

Minimally Invasive Quadriceps Sparing Total Knee Arthroplasty

PURPOSES: To compare the radiologic results in the minimally invasive quadriceps sparing total knee arthroplasty(MIS-QS TKA) with those in conventional total knee arthroplasty(TKA). MATERIALS AND METHODS: Between June 2004 and December 2004, we underwent 20 MIS-QS TKAs (group I) and 20 conventional TKAs(group II). All cases were female with osteoarthritis. The average age was 68.0 years in group I and 65.0 years in group II. The mechanical axis and the implant position were measured by 2 observers according to the reontgenographic evaluation system of the American Knee Society. RESULTS: The mean length of skin incision was 9.2 cm in group I and 16.1 cm in group II. The mean operative time was 127 minutes in group I and 85 minutes in group II. The mean postoperative mechanical axis was varus 1.35 degrees in group I and varus 0.37 degrees in group II. And the mean alpha, beta, gamma and delta angle were 94.9, 90.6, 4.5 and 85.5 degrees in group I, and 94.3, 91.4, 4.7 and 84.6 degrees in group II, respectively. There was no significant difference in the radiologic results between both groups. CONCLUSIONS: There was no significant difference in the implant position and mechanical axis between MIS-QS TKA group and conventional TKA group. Average skin incision was shorter in MIS-QS TKA, but longer operation time taken compared to that of conventional TKA.

MR Imaging in the Evaluation of Mullerian Duct Anomalies

PURPOSE: To assess the role of MRI in the diagnosis of uterine anomaly. MATERIAL AND METHODS: MRI(n:15), hysterosalpingography(n:7) and ultrasonography(n:7) were performed in 15 patients with suspected MullerJan duct anomaly. Nine cases were proved by operation and six cases were diagnoed with imaging and clinical findings. According to Buttram and Gibbons modified classification, the anomalies were 4 cases of class I, 2 cases of class III, one case of class IV, and 8 cases of class V. RESULTS: MRI enabled accurate diagnoses of anomalies in all cases, but HSG and USG showed wrong diagnoses in 3 of 7 cases and in 1 of 7 cases. CONCLUSION: MRI, especially T2-weighted images parallel to long axis of uterine corpus, was very useful in diagnosis of the Mullerian duct anomaly, because it could depict exactly the external fundal contour, intercornual distance, septum, transverse vaginal septum, and associated abnormalities such as hematocolpos and hematometra.

Retroperitoneal cystic lymphangioma in an aged man: report of a case and review of the literature

Retroperitoneal cystic lymphangioma is a rare benign tumor which had previously been difficult to diagnose preoperatively by conventional radiographic technique(1). Recent reports describe the computed tomographic and ultrasonographic findings in cystic lymphangioma(1,2). We report a case of retroperitoneal cystic lymphangioma, accurately diagnosed by lymphography, with computed tomographic findings and percutaneous drainage findings. To the best of out knowledge, this is the most aged case of retroperitoneal cystic lymphangioma of preoperatively diagnosed.