Incidence of Deep Vein Thrombosis after Major HipSurgery and Diagnostic Value of D-dimer / 대한정형외과학회잡지

PURPOSE: To evaluate the incidence of deep vein thrombosis (DVT) after major hip surgery along with the efficacy of the D-dimer as a routine noninvasive-screening test for DVT. MATERIALS AND METHODS: From May 2003 to August 2004, 289 patients who underwent major hip surgery were evaluated prospectively. All the patients underwent B-mode ultrasonography (US) preoperatively, and venography or US on postoperative 7 to 10 days. The D-dimer level was also estimated preoperatively, and at 3 and 7 days after surgery. RESULTS: The preoperative D-dimer level was an average 0.60 ug/ml. DVT was encountered in 29 patients (10.1%) and in 28.9% of those over 60 years of age (p<0.05). Three days after surgery, the average D-dimer level was 3.82 ug/ml in the DVT positive patients and 2.26 ug/ml in the DVT negative patients. Seven days after surgery, the average D-dimer level in the DVT positive and negative patients was 5.19 ug/ml and 2.89 ug/ml. The most predictable D-dimer level for DVT 3 and 7 days after surgery were 2.585 ug/ml and 3.625 ug/ml, respectively. CONCLUSION: The overall incidence of DVT in our patients undergoing major hip surgery seemed lower than in Western populations. However, there was a significantly increasing tendency if the development of DVT in the older age group. We also recommend a D-dimer assay at postoperative 7 days as a valuable screening test for detection of DVT.

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.

Revision Total Knee Arthroplasty of Failed Unicompartmental Knee Arthroplasty

PURPOSE: To analyze the failure mechanism, complexity of surgery, complication and outcome of revision of failed unicompartmental knee arthroplasty(UKA). MATERIALS AND METHODS: 14 patients(16 knees) were followed up a mean 70 months. The patients were a mean age of 58.2 years at time of UKA and predominantly female(85%). Revision surgery was done 14 to 104 months with an average time of 4 years 10 months after UKA. The UKA component that were revised include 10 Microloc, 4 Allegretto, 1 Oxford and 1 Marmor modular II. Clinical and radiographic evaluation were completed preoperatively and at last follow-up. The scoring system used in this study is Hospital for Special Surgery(HSS) knee score. Radiographic assessment was performed using Bauer's method(tibio-femoral angle) and American knee society roentgenographic evaluation system. RESULTS: The predominant failure mechanism was polyethylene wear and femoral component loosening. At the last follow-up, the average HSS knee score significantly improved from 60 to 86. Average tibio-femoral angle was corrected from varus 2o to valgus 5o. The implant type used for the revision was PFC-PS. 11 knees required local autograft but no allograft were used. Femoral block augment and tibial metal wedges with stem were also used to reconstruct the defect. There were 2 cases of complications, subluxation of patella and deep infection after intraarticular injection at local clinic. CONCLUSION: Polyethylene wear and femoral component loosening was common failure mechanism in revision of UKA. Bone defects needed to reconstruct were detected in 11 cases but autograft was enough to reconstruct the defect. Result of failed UKA compares favorably with those of total knee revision.