Objective: Pseudogout is an acute arthritis induced by calcium pyrophosphate dihydrate (CPPD) crystal deposition. This form of arthritis frequently develops in the elderly population. Although the etiology of attacks is unclear, risk factors include osteoarthrosis and hyperparathyroidism. In addition, a relationship with ‘heart/brain disease’ has been reported. In our hospital, in which the Departments of Neurosurgery and Cardiology respectively account for 70% of the total number of beds, we investigated patients with pseudogout.

Methods: There were 21 patients (8 males; 13 females) with a mean age of 83.5 years, referred to our department with symptoms of acute arthritis, and who were subsequently diagnosed with pseudogout. A diagnosis of pseudogout was made based on intra-articular calcification on plain radiography or the presence of CPPD crystals in articular fluid.

Results: The most frequent site of pseudogout was the knee, followed by the wrist. Most patients showed arthritis symptoms consisting of fever and severe pain. The mean interval from admission until onset was 5.1 days. In all subjects, non-steroidal anti-inflammatory drugs (NSAIDs) were administered, which led to remission within one week. However, an improvement was achieved the following day in patients using NSAIDs combined with intra-articular steroid injections.

Conclusion: In elderly patients with acute arthritis, pseudogout should be considered and investigated. Radiological chondrocalcinosis is suggestive, but the diagnosis is confirmed by the presence of CPPD crystals from a joint aspirate. Early treatment should be performed once pseudogout is diagnosed, ensuring that infection is definitively ruled out.

Objective: The objective of this study was to investigate the management of bone defects on revision total knee arthroplasty.

Methods: A total of 41 knee joints in 37 patients who underwent revision arthroplasty at our hospital (36 knee joints in 32 females, 5 knee joints in 5 males) were examined in this study. The mean age at revision arthroplasty was 65.7 years old (range, 28-82 years old) and the mean period from initial surgery to revision surgery was 9.8 years, respectively. Bone defects were evaluated using the Anderson Orthopaedic Research Institute classification. The management for each bone defect was also investigated.

Results: Bone defects of typesⅠ, Ⅱa and Ⅱb were present in 15 (42.9%), 12 (34.3%), and eight (22.8%) knee joints, respectively, on the femoral side, and in 13 (36.1%), 17 (47.2%), and six (16.7%) knee joints, respectively, on the tibial side. There were no type Ⅲ defects. On the femoral side, type Ⅰ defects were treated only with cement and autogenous bone grafting. In addition to these treatments, metal augmentation was used for five knee joints with type Ⅱa defects (41.7%) and five knee joints with type Ⅱb defects (62.5%). Autogenous iliac bone grafting was used for four knee joints with type Ⅱb defects (50%). On the tibial side, cement, autogenous bone grafting and thicker polyethylene inserts were used for type Ⅰ defects. Cement and autogenous bone grafting were used for type Ⅱ defects, with metal augmentation used for two knee joints with type Ⅱa defects (11.8%) and two knee joints with type Ⅱb defects (33.3%). Autogenous iliac bone grafting was used for four knee joints with type Ⅱb defects (66.7%).

Conclusion: An evaluation of patients with bone defects treated at our department showed that the management of type Ⅰ bone defects can be by replacement cement and autogenous bone grafting, and that long stem and metal augmentation are not necessary since the implant is the primary prosthesis. However, use of a long stem should be considered when the initial fixity of the implant is not sufficient due to the bone properties. The management of type Ⅱ defects by use of cement, autogenous bone grafting, and metal augmentation should be used concomitantly, and an implant with a long stem should be selected. In the management of type Ⅲ bone defects, allogeneic bone grafting should be considered, in addition to use of an implant with a long stem that can reach the diaphyseal region, particularly for a special component.

Introduction: Several methods have been proposed to determine proper femoral component rotation alignment in total knee arthroplasty (TKA). Usually the epicondylar axis, the posterior condylar axis and Whiteside’s line are used for landmarks. However, sometimes recognition of these landmarks is difficult intraoperatively. We decide on the rotation angle of the femoral component using the epicondylar view via a preoperative radiograph. The angle consists of the clinical epicondylar axis (CEA) and the posterior condyle line minus two degrees. We think the influence of the residual cartilage of the posterior lateral femoral condyle is about two degrees in varus osteoarthritis (OA).

Objective: The objective of this study was to evaluate the rotation alignment of the femoral component after TKA, and the usefulness of our method for the decision of femoral component rotation alignment.

Methods: There were 43 patients (7 males, 36 females) with varus OA who underwent primary TKA. The average age was 78.1 years (range, 64-87 years). The rotation angle of the femoral component was decided by the above-mentioned method. We evaluated the angle between the posterior border of the femoral component and the CEA, and the surgical epicondular axis (SEA) using postoperative computed tomography. These angles were expressed as∠CEA and∠SEA. External rotation was expressed as plus.

Results: The mean∠CEA was−1.1 (−5-1)°. The mean∠SEA was 0.48 (−3-3)°. The mean angle of∠SEA−∠CEA was 1.5 (0-3)°. The femoral component was placed in internal rotation to CEA and parallel to SEA.

Conclusion: Internal placement of the femoral component was considered to be caused abnormal patella tracking and dislocation and low value of Knee Society Knee scoring. We think that it can be difficult to recognize some landmarks intraoperatively. We decide on the rotation angle of the femoral component using the epicondylar view of preoperative radiographs. From the results of this study, the femoral component was placed in internal rotation to CEA and parallel to SEA. We conclude that our method for the decision of the femoral component rotation alignment is useful for TKA of varus OA of the knee.

Objective: Anterior cruciate ligament deficiency of the knee can lead to secondary osteoarthritis of the patellofemoral joint (PFJ). About 20% of patients who have undergone total knee arthroplasty (TKA) have not been satisfied. Fujikawa observed the cartilage lesion of the patella (inferior facet>odd facet>medial facet) for osteoarthritis of the PFJ. The JOURNEY^TM II Bi-Cruciate Stabilized (BCS) Total Knee System, that substitutes for the anterior and posterior cruciate ligaments, may cause pressure on the PFJ compared to conventional (Con) TKA. The purpose of this study was to examine the effect on the PFJ for BCS.

Methods: We prospectively analyzed patients with BCS TKA (20 knees) and Con TKA (20 knees) for a year postoperatively. Several evaluation methods were used for clinical outcomes including the Knee Society Score (KSS), anterior knee pain, plain radiographs, and quantitative analysis of two-dimensional bone formation levels (proposed by the American Society for Bone and Mineral Research ; bone mineral content/total volume: BMC/TV value) measured every three months postoperatively. Two-dimensional bone morphometry software (TRI/3D-BON64, Ratoc System Engineering Co., Ltd. Tokyo, Japan) was then used to calculate the structural parameters in the region of interest (ROI 1: upper part of the patella, ROI 2: center of the patella, and ROI 3: inferior part of the patella).

Results: No significant difference was recognized in age, body mass index, KSS, or between the two groups postoperatively. There were significantly higher BMC/TV values in ROI 1 for BCS TKA patients compared to Con TKA patients at 12 months postoperatively (P<0.05).

Conclusion: This study reveals that the BCS TKA, which substitutes for both the anterior and posterior cruciate ligaments, is similar to the kinematic pathway of the normal knee for results of bony structural parameters in the PFJ.

Objective: Accurate and precise bone incision and implantation are important for good clinical results in total knee arthroplasty (TKA). However, it is said that approximately 10-20% of malalignments occurs with conventional devices. Navigation is one of the tool to prevent malalignment. We estimated the accuracy of locating the calculated center of the ankle in two different navigation systems (precisioN and iASSIST^TM) in this study.

Methods: Thirty patients who received TKAs in our hospital were included in this study. Preoperative computed tomography data were used to characterize the shape of each tibia and to establish the true centre of each ankle. The virtual center of each ankle was set as the midpoint of the bilateral malleoli in iASSIST^TM, while it was set at 44% of spots from the medial malleoli in precisioN, respectively.

Results: Compared with the true ankle center, the ankle center of precisioN was present 1.9 mm medial, 2.7 mm posterior, and 3.2 mm distal, whereas the ankle center of iASSIST^TM was present 1.6 mm lateral, 3.5 mm posterior, and 3.2 mm distal without skin thickness, respectively. Also, the ankle center of precisioN was present 2.4 mm medial, 2.7 mm posterior, and 3.4 mm distal, whereas the ankle center of iASSIST^TM was present 1.7 mm lateral, 3.6 mm posterior, and 3.9 mm distal with skin thickness, respectively.

Conclusion: In this study, the error of recognizing the centre of the ankle was less than 1 degree in two different image-free navigation systems. If adequate reference points can be digitized, the application of different navigation systems can be utilized with accuracy intraoperatively.

Objective: Currently, there is no consensus on the value of patient-matched instrumentation (PMI) during total knee arthroplasty (TKA). However, most have been evaluations of the magnetic resonance imaging-based PMI. There is still controversy about computed tomography (CT)-based PMI. The purpose of this study was to analyze the accuracy of CT-based PMI with two-dimentional (2D) and three-dimentional (3D) evaluation.

Methods: Fifty seven consecutive patients with severe osteoarthritis underwent a primary TKA using either conventional instruments (CI) or CT-based PMI. We used 2D evaluation, which consisted of long-standing radiographs to measure the hip-knee-ankle angle (HKA), the frontal femoral component angle (FFC), and the frontal tibial component angle (FTC). The femoral and tibial component positions were analyzed more precisely with a 3D matching bone model made via pre- and postoperative CT images. For a 3D matching bone model made from these models, a 2D projection of the pre- and postoperative component positioning planes was made, and the projection angle was measured as angle error compared to the preoperative planned position. The blood loss and D-dimer level on postoperative day 7 were also recorded.

Results: Twenty knees in the CI group and 37 knees in the PMI group were available for analysis. There were few differences in postoperative average HKA angle, FFC and FTC. On the other hand, the percentage of HKA outliers was significantly higher in the CI group than the PMI group (CI: 35%; PMI: 10.8%, P=0.027) with 2D evaluation. In the component position, the PMI group showed a significantly decreased outliers rate of tibial component positioning for varus/valgus (CI: 29.4%; PMI: 5.6%, P=0.017) and posterior slope (CI: 41.2%; PMI: 11.1%, P=0.011) with 3D evaluation. The average D-dimer level on postoperative day 7 was significantly decreased in the PMI group.

Conclusion: CT-based PMI significantly reduced the number of outliers in the mechanical axis and component positioning compared to conventional instrumentation. CT-based PMI is expected to improve the mechanical axis and component alignment in total knee arthroplasty.

Objective: Patients with osteoarthritis of the thumb carpometacarpal (CM) joint should initially be treated conservatively such as with splinting, non-steroidal anti-inflammatory drugs, intra-articular injection of steroids, and modification of patient activities. The purpose of this paper was to investigate the results of those conservative treatments.

Methods: One hundred and thirty six joints of 127 patients were divided into three groups-an injection group (75 joints), a splinting group (short opponens type; 28 joints), and a combined injection/splinting group (33 joints). The patient records were examined retrospectively at the mean follow-up period of 3 years and 7 months. The results were evaluated due to the degree of pain and functional disturbance in activities of daily living.

Results: In the injection group, 52% reported “excellent” and 22% reported “good”. Thirty-nine percent of the splinting group and 24% of the combined injection/splinting group reported “excellent” whereas 14% and 18% of the respective groups reported “good”.

According to the statistical analysis, the injection group obtained better results than the combined injection/splinting group; the older group (above 61 years old) did better than the younger group (below 60 years old). In cases of Eaton stage 1, the injection group showed better results than the other groups. There was no significant difference among the three treatment groups in stage 2 and stage 3. Splinting did not show significant effectiveness because the splint was hard and uncomfortable to wear. Other factors such as occupation, the number of injections and the period of wearing the splint did not statistically affect the clinical results.

Conclusion: Corticoteroid injection is useful in the early stages of arthritis. Splinting is also effective, but comfort and the ease of use for patients is important, and may be limited by the use of such a device.

 We created a full-scale and full-colour 3-dimensional salt model with computed tomography based data for a 69-year-old woman, who underwent Schanz osteotomy of her proximal femurs in her youth. We composed a preoperative simulation for evaluation and as a result, we chose the anterolateral supine approach. We transplanted the bulk femoral bone autograft to the acetabulum. We used the smallest size of Wagner type stem, Stellaris^® (Mathys), but the neck offset was still too long. We also performed advancement of the greater trochanter consistent with the Paavilainen method.

 Full-scale and full-colour 3-dimensional salt modelling was useful in the preoperative simulation and image training for the surgeon, but it was difficult to predict the soft tissue balances and to evaluate the intraoperative bone qualities.

 Recently, concerns have been raised about adverse reactions to metal debris (ARMD) after receiving metal-on-metal (MOM) total hip arthroplasty (THA). The diagnosis of ARMD is often difficult. This case report describes the usefulness of hip arthroscopy in diagnosing ARMD after a MOM THA.

 A 63-year-old woman underwent a primary right THA for osteoarthritis with a M2a-taper MOM articulation [Biomet^®, Inc., Warsaw, IN]. Her postoperative course was uneventful. One year and eight months later, however, she developed right groin pain and became unable to mobilise. A plain radiograph of her left hip showed radiolucencies around the acetabular cup, suggesting loosening of the acetabular components. A computed tomography scan demonstrated a large mass anterior to the hip joint. Serologic tests showed no elevation of leukocytes or C-reactive protein. These findings suggested the possibility of ARMD and/or occult infection. A hip arthroscopy was then performed, which revealed necrotic soft tissue debris within the joint. The lesion was arthroscopically biopsied and samples were analysed through bacterial culture and histology. The bacterial culture was negative, and histological analysis showed multiple macrophages that were phagocytizing metal debris. These results established a definitive diagnosis of ARMD. During the following month, a revision surgery with debridement of the pseudotumor was performed. The femoral stem was well-fixed. The acetabular components and the head were replaced. The metal liner was replaced with a polyethylene liner and the head was changed to a zirconia type. Intraoperative cultures were later found to be negative and the surgical specimen revealed the same findings with those obtained by the previous arthroscopy. Recovery from the surgery was uneventful.

 Tibial shaft spiral fractures are often associated with proximal fibula fractures. Although not well known, posterior malleolar fractures are sometimes involved in tibial shaft spiral fractures.

 We report three cases of occult posterior malleolar fractures associated with tibial shaft fractures.

 In all three cases posterior malleolar fractures were recognized initially on plain radiographs. In one case a posterior malleolar fracture was retrospectively noted on computed tomography (CT) scans after intramedullary nailing of the tibial shaft fracture. In the other two cases posterior malleolar fractures were detected on CT scans and were stabilized with a cannulated screw before nailing of the tibial shaft fractures. Missed and untreated posterior malleolar fractures may influence the progress of postoperative rehabilitation and lead to ankle osteoarthritis.

 A high index of suspicion is required in the treatment of tibial spiral shaft fractures. We recommend CT evaluation in search for posterior malleolar fractures in patients with tibial spiral shaft fractures.