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Roh Y.W.,Joint Reconstruction Center | Kim T.W.,Seoul National University | Lee S.,Seoul National University | Seong S.C.,Seoul National University | Lee M.C.,Seoul National University
Clinical Orthopaedics and Related Research

Background: Patient-specific CT-based instrumentation may reduce implant malpositioning and improve alignment in TKA. However, it is not known whether this innovation is an advance that benefits patients. Questions/purposes: We evaluated (1) the precision of patient-specific TKA by comparing the incidence of outliers in postoperative alignment between TKAs using patient-specific instruments and TKAs using conventional instruments, and (2) the reliability of patient-specific instruments by intraoperatively investigating whether the surgery could be completed with patient-specific instruments alone. Methods: In this randomized controlled trial, we compared patient-specific TKA instruments from one manufacturer (n = 50) with conventional TKA instruments (n = 50). Postoperative hip-knee-ankle angles, femoral component rotation, and coronal and sagittal alignments of each component were measured. The validity of the patient-specific instrument was examined using cross-checking procedures with conventional instruments during the surgeries. When the procedure could not be completed accurately with patient-specific instruments, the procedure was converted to TKA using conventional instruments, and the frequency of this occurrence was tallied. Results: Outliers in the hip-knee-ankle angle were comparable between groups (12% in the patient-specific instrument group and 10% in the conventional instrument group). Other parameters such as sagittal alignment and femoral component rotation did not differ in terms of outliers. Patient-specific guides were abandoned in eight knees (16%) during the surgery because of malrotation of the femoral components and decreased slope of the tibia. Conclusions: Accuracy was comparable between TKAs done with patient-specific instruments and those done with conventional instruments. However, the patient-specific instrument procedures had to be aborted frequently, incurring expenses that did not benefit patients. Level of Evidence: Level II, therapeutic study. See Instructions for Authors for a complete description of levels of evidence. © 2013 The Association of Bone and Joint Surgeons®. Source

Kwon S.K.,Yonsei University | Kwon S.K.,Joint Reconstruction Center | Yang I.H.,Yonsei University | Bai S.J.,Yonsei University | Han C.D.,Yonsei University
Yonsei Medical Journal

Purpose: Although the analgesic effects of corticosteroids have been well documented, little information is available on periarticular injection (PI) containing corticosteroids for early postoperative pain management after total knee arthroplasty (TKA). We performed a prospective double-blind randomized trial to evaluate the efficacy and safety of an intraoperative corticosteroid PI in patients undergoing TKA. Materials and Methods: Seventy-six consecutive female patients undergoing bilateral staged TKA were randomized to receive steroid or non-steroid PI, with 3 months separating the procedures. The steroid group received PI with a mixture containing triamcinolone acetonide (40 mg). The non-steroid group received the same injection mixture without corticosteroid. During the postoperative period, nighttime pain, functional recovery [straight leg raising (SLR) ability and maximal flexion], patient satisfaction, and complications were recorded. Short-term postoperative clinical scores and patient satisfaction were evaluated at 6 months. Results: The pain level was significantly lower in the PI steroid than the non-steroid group on the night of the operation (VAS, 1.2 vs. 2.3; p=0.021). Rebound pain was observed in both groups at POD1 (VAS, 3.2 vs. 3.8; p=0.248), but pain remained at a low level thereafter. No significant differences were seen in maximal flexion, frequency of acute rescuer, clinical scores, and patient satisfaction. The steroid group was able to perform SLR earlier than the non-steroid group (p=0.013). The incidence of complications was similar between the groups. Conclusion: PI containing a corticosteroid provided an additional pain-relieving effect on the night of the operation. In addition, corticosteroid PI did not increase the perioperative complications of TKA. © Yonsei University College of Medicine 2014. Source

Lee S.A.,Kyung Hee University | Choi S.-H.,Sungkyunkwan University | Chang M.J.,Joint Reconstruction Center
BMC Musculoskeletal Disorders

Background: Anatomic limb alignment often differs from mechanical limb alignment after total knee arthroplasty (TKA). We sought to assess the accuracy, specificity, and sensitivity for each of three commonly used ranges for anatomic limb alignment (3-9°, 5-10° and 2-10°) in predicting an acceptable range (neutral ± 3°) for mechanical limb alignment after TKA. We also assessed whether the accuracy of anatomic limb alignment was affected by anatomic variation. Methods: This retrospective study included 314 primary TKAs. The alignment of the limb was measured with both anatomic and mechanical methods of measurement. We also measured anatomic variation, including the femoral bowing angle, tibial bowing angle, and neck-shaft angle of the femur. All angles were measured on the same full-length standing anteroposterior radiographs. The accuracy, specificity, and sensitivity for each range of anatomic limb alignment were calculated and compared using mechanical limb alignment as the reference standard. The associations between the accuracy of anatomic limb alignment and anatomic variation were also determined. Results: The range of 2-10° for anatomic limb alignment showed the highest accuracy, but it was only 73 % (3-9°, 65 %; 5-10°, 67 %). The specificity of the 2-10° range was 81 %, which was higher than that of the other ranges (3-9°, 69 %; 5-10°, 67 %). However, the sensitivity of the 2-10° range to predict varus malalignment was only 16 % (3-9°, 35 %; 5-10°, 68 %). In addition, the sensitivity of the 2-10° range to predict valgus malalignment was only 43 % (3-9°, 71 %; 5-10°, 43 %). The accuracy of anatomical limb alignment was lower for knees with greater femoral (odds ratio = 1.2) and tibial (odds ratio = 1.2) bowing. Conclusions: Anatomic limb alignment did not accurately predict mechanical limb alignment after TKA, and its accuracy was affected by anatomic variation. Thus, alignment after TKA should be assessed by measuring mechanical alignment rather than anatomic alignment. © 2015 Lee et al. Source

Seo J.G.,Sungkyunkwan University | Lee S.A.,Kyung Hee University | Moon Y.-W.,Sungkyunkwan University | Lee B.H.,Sungkyunkwan University | And 2 more authors.
Archives of Orthopaedic and Trauma Surgery

Introduction: The aim of this study was to determine whether pain intensity and wound complication rates differ between patients with and without preservation of the infrapatellar fat pad (IPFP) after minimally invasive total knee arthroplasty (TKA). The authors also sought to determine whether IPFP preservation affects operation time. Materials and methods: This retrospective study included 448 knees with primary TKA. The IPFP was totally resected in 201 knees (IPFP-R group), and was preserved in 247 knees (IPFP-P group). Pain score was determined using the visual analog scale during the first 72 h after surgery. Wound complication rates and operation times were also evaluated. A wound complication was defined as persistent wound drainage for three or more days after surgery. Results: There was no difference in pain levels between the two groups. However, there were fewer wound complications in the IPFP-P group (3 %) than in the IPFP-R group (13 %). The operation time was longer in the IPFP-P group than in the IPFP-R group (70 vs. 64 min, respectively). Conclusions: Although IPFP preservation delayed operation time, it decreased wound complications after MIS TKA. These findings are important to consider when deciding whether or not to resect the IPFP. Whenever possible, IPFP preservation is probably the preferred technique to reduce wound complications. © 2015, Springer-Verlag Berlin Heidelberg. Source

Chung B.J.,Joint Reconstruction Center | Park Y.B.,Joint Reconstruction Center

There is no known causal link between total knee arthroplasty (TKA) and pigmented villonodular synovitis (PVNS). There also is no known relationship between PVNS and implant loosening after TKA in the literature. This article presents a case of PVNS in a patient undergoing revision TKA for tibial component loosening. A 74-year-old woman who had undergone cemented bilateral TKA 5 years earlier presented with painful swelling in her right knee. At the time of the primary TKA, no abnormal signs were found in the synovial membrane. Routine follow-up radiographs did not indicate implant loosening. At the patient's final follow-up examination before revision surgery, a radiolucent lesion was found below the tibial component. During revision surgery, there was focal proliferation of the synovial tissue with heavy pigmentation around the anteromedial part of the tibial component. The abnormal tissue was removed, and the tibial component was exchanged. The articular surface of the polyethylene was not damaged, and backside wear was not found. For the revision surgery, 5-mm thick medial metal block and extension stem were used. Histological analysis of the resected tissue revealed the typical appearance of PVNS. We present a typical case of PVNS found during revision TKA 5 years after primary TKA. It is hoped this report will encourage surgeons to consider PVNS in the differential diagnosis of patients who present with painful swelling of the knee and to consider PVNS as one of the causes of implant loosening after TKA. Further research about causal factors between PVNS and implant loosening are needed. Source

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