Objective: To assess the relationship between bone morphology of medial compartment knee osteoarthritis (OA) and osteoporosis.

Methods: We investigated 43 patients with OA of the knee (12 men and 31 females) who underwent total knee arthroplasty between January 2016 and June 2016, inclusive. The mean age was 74.3 years. Bone mineral density (BMD) was measured in the proximal femur using dual energy X-ray absorptiometry. Osteoporosis was defined as a BMD of less than 70% of peak bone mass according to the criteria of the Japanese Society for Bone and Mineral Research. Knee radiographs were obtained with the patient standing on one leg. The femorotibial angle (FTA), femoral condylar-femoral shaft angle (FC-FS), tibial plateau-tibial shaft angle (TP-TS) were used as parameters of deformity. OA was classified into two types, depression-type and slope-type by the bone morphology of the medial tibial plateau. The depression-type was defined as the bottom of the articular surface being at the same or lower level than the medial tibial condyle. The slope-type was defined as the bottom of the articular surface being higher than the level of the medial tibial condyle.

Results: In patients with OA of the knee, there was no significant association between the presence of osteoporosis and radiographic parameters measured in this study. However, the frequency of the depression-type of OA was significantly higher in the patient group with osteoporosis, compared with the group without osteoporosis.

Conclusion: The presence of osteoporosis had no significant effect on coronal alignment of the knee in patients with OA. However, the frequency of the depression of the medial tibial plateau was shown to be significantly higher in patients with osteoporosis.

Background: We have developed a novel fixation system (TriS Medial HTO Plate System^®; Olympus Terumo Biomaterials, Japan) for medial open-wedge high tibial osteotomy (OWHTO). The purpose of this study was to clarify the short-term clinical outcome of OWHTO using TriS plates.

Methods: Fifty consecutive patients (54 knees) who underwent OWHTO with a locking plate (TriS plate) were enrolled in this study between 2014 and 2016, inclusive. Inclusion criteria involved patients who had persistent pain due to medial osteoarthritis or spontaneous osteonecrosis of the knee. There were 31 women and 19 men with a mean age of 61.7 (36-78) years at the time of surgery. Intraoperatively, we performed a biplanar osteotomy of the tibia. Beta-tricalcium phosphate spacer (Osferion 60^®, Olympus Terumo Biomaterials, Japan) was implanted in the opening space. Following that, the TriS plate was implanted onto the tibia. All patients underwent clinical, radiological, and computed tomography evaluations before surgery and at six months after surgery.

Results: Postoperatively, the mean Japan Orthopaedic Association score significantly improved from 68.9 to 89.0 points (P<0.001). At the final examination, the lateral femorotibial angle changed from 180.2 degrees to 169.7 degrees. The weight-bearing line percentage shifted to pass through a point 69.1% lateral from the medial edge of tibial plateau. The Insall-Salvati ratio and the mean posterior slope did not significantly change after surgery. The following complications occurred; one case of superficial wound infection (1.9%) and seven cases (13.0%) of lateral hinge fracture: six cases of type Ⅰ, and one case of type Ⅲ according to Takeuchi’s classification. There were no severe complications, such as pseudoarthrosis or deep surgical site infection.

Conclusions: Using the TriS plate system, the medial knee pain resolved in all cases. This study demonstrates that the TriS plate is a useful system for medial OWHTO procedures.

Objective: We have developed a posterior-stabilized (PS) total knee prosthesis designed for Japanese patients (ACTIYAS^®, Kyocera Medical, Japan), and started clinical trials from 2010. Herein we report our two-year results of ACTIYAS^® compared with those of the NexGen^® LPS-Flex (Zimmer Biomet, USA), another high-flexion PS prosthesis, which is the most popular prosthesis.

Methods: All cases requiring primary total knee arthroplasty (TKA) were due to osteoarthritis (OA). Patients with rheumatoid arthritis were excluded from this study. The group receiving the ACTIYAS^® prosthesis (group A) consisted of 94 cases (141 knees), with a mean age of 76 years, and with surgery performed from November 2010 to August 2012 inclusive. The group receiving the NexGen^® LPS-Flex (group B) consisted of 82 cases (120 knees), with a mean age 75 years, who underwent surgery from January 2007 to December 2008, inclusive. We evaluated the groups’ Knee Society Scores (KSS), the range of motion (ROM) preoperatively, on the day of discharge, 3, 6, 12, and 24 months postoperatively. Knee satisfaction level and hospitalization period were also evaluated.

Result: KSS at one year postoperatively was significantly improved compared with the preoperative score in both group A and B, respectively. The ROM change in group A was −4.6/125, −6/108, −4.2/118, −3.0/122, −2.3/124, and−1.9/126, while in group B it was −5.2/127, −5.5/112, −3.1/122, −2.3/124, −1.0/128, and−1.1/128, preoperatively, on the day of discharge, postoperatively at 3, 6, 12, and 24 months, respectively. Though the ROM of group B at 12 month was better than that of group A, there was no significant difference regarding KSS at each period between the two groups. Group A had a significantly higher level of knee satisfaction (85.4 points) than group B (80.6 points), respectively (P<0.01). There was a shortened hospitalization period in group A (22.9 days) than in group B (25.3 days), respectively (P<0.01).

Conclusion: ACTIYAS^® achieved better patient satisfaction and was associated with a shorter hospital stay compared to the LPS-Flex posterior-stabilized total knee prosthesis.

Objective: In patients undergoing total knee arthroplasty (TKA), removing preoperative flexion contractures is crucial. We analyzed the relationship of preoperative and postoperative flexion contractures with the extension gap during surgery.

Methods: We examined 100 knees which had undergone TKA (FINE^® Total Knee System CR) using the “pre-cut technique” at least six months previously. We measured flexion contractures before surgery and five days and six months postoperatively. Extension gaps were measured after setting the pre-cut trial and trial components.

Results: The flexion contracture was 10.3±7.9° (0-40°) before surgery and 3.1±3.6° (0-20°) and 2.6±3.2° (0-13°) at five days and six months postoperatively, respectively. The extension gap on the pre-cut trial and trial components was 8.0±2.6 (3-15) mm and 11.6±1.1 (10-17) mm, respectively. In some cases, flexion contractures were worse (>5°) at six months than at five days. It was apparent that preoperative flexion contractures were the only significant exacerbating factor. In cases with a large preoperative flexion contracture angle, soft tissue balance was significantly adjusted to enlarge the extension gap. In the cases of soft tissue balancing, preoperative flexion contractures in cases with exacerbation were significantly worse than in non-exacerbation cases; preoperative flexion contracture angles were<20° in most non-exacerbation cases, but>20° in approximately half of the exacerbation cases.

Conclusion: In patients undergoing TKA, if preoperative flexion contracture angles are>20°, a solution strategy should be considered.

Objective: Venous thromboembolism (VTE) is a complication that should be avoided when performing arthroplasty. We examined the prophylactic and therapeutic effects of anticoagulation on postsurgical onset of distal deep vein thrombosis (DVT).

Methods: The screened subjects included 139 patients who underwent hip and knee arthroplasty. After excluding seven cases of existing proximal DVT, a total of 132 were enrolled in the study. DVT was evaluated by presurgical ultrasonography and ultrasonography at both 3 and 14 days after surgery. Pulmonary embolism (PE) as a complication of DVT, was identified by either contrast-enhanced chest computed tomography or lung perfusion scintigraphy. Anticoagulation after surgery included either fondaparinux, enoxaparin, or edoxaban. A total of 41 patients were treated with fondaparinux (group A), while 35 patients were treated with enoxaparin (group B), and 56 patients were treated with edoxaban (group C). Prophylactic anticoagulant for the 35 patients with asymptomatic distal DVT continued for 14 days (Prevention group), while the 11 cases of symptomatic PE received treatment doses of anticoagulation (Treatment group 11 cases). The incidence of VTE up to postoperative day 14 between groups A, B, and group C was evaluated. We studied thrombus formation, the incidence of thrombus dissolution, and bleeding for up to 14 days after surgery in both the prophylactic and treatment groups.

Results: VTE for up to 14 days after surgery was found in 15 patients in group A (36.5%), 11 patients in group B (31.4%), and 20 patients in group C (35.7%). We found that there was no increase in the incidence of thrombus formation at postoperative day 14 in both the prophylactic and the treatment groups. The thrombosis disappeared by postoperative day 14 in 24 patients in the prophylactic group (68.5%) and in eight patients in the treatment group (72.3%). Bleeding was not observed in the prophylactic group (0%), and three patients had bleeding in the treatment group (27.2%).

Conclusion: Anticoagulation for up to 14 days after arthroplasty suppresses DVT when used prophylactically, and such therapy also reduced subsequent bleeding.

Objective: The purpose of this study was to investigate the usefulness of postoperative early exercise therapy for deep vein thrombosis (DVT) prevention after total knee arthroplasty (TKA).

Methods: The series consisted of 396 knees in 198 patients, undergoing TKA between August 2014 and November 2015, inclusive. Patients included 41 men and 157 women, with a mean age of 72.4 years, and a mean body mass index of 25.2 kg/m². We performed lower limb venous ultrasonography before and two weeks after TKA for all patients, and investigated the incidence and the site of DVT. All patients underwent exercise therapy immediately after surgery.

Results: The incidence of DVT was 3.9%. All cases experienced distal DVTs. There were no patients with clinical symptoms of DVT and/or thromboembolism.

Conclusion: The early exercise therapy after TKA appears effective for DVT prevention.

Introduction: The superior approach (SA) in total hip arthroplasty (THA) is one of the muscle sparing posterior approaches. We describe this method and report the radiographic outcomes of the first 30 hip arthroplasties performed using a SA.

Methods: The method for THA: The patient was placed in the lateral decubitus position with the operative leg in approximately 60° of flexion, 40° of adduction, and 20° of internal rotation. The gluteus medius muscle was retracted anteriorly, and the piriformis muscle posteriorly, to exposure the hip capsule. The femoral canal was entered at the trochanteric fossa with a round chisel. The femoral broaches were performed before the femoral neck osteotomy. The femoral head was removed after the osteotomy. The acetabular cup was impacted with anteversion of the transverse acetabular ligament.

 The method for hip hemi-arthroplasty (HA): First, the outer head was placed in the acetabular fossa; second, the femoral stem was placed and the inner head was impacted. The outer and inner head were set up in the acetabular fossa.

Results: The SA group included 12 THAs and 18 HAs. In the THA group, the mean operative duration was 106±18 minutes, the mean varus angle of the stem was 0±1.5 degrees, the mean inclination of the cup was 45±8 degrees, the mean anteversion of the cup was 9±8 degrees and the mean limb length discrepancy was 6±4 mm. In the HA group, the mean duration was 60±17 minutes, the mean varus angle of the stem was 1±2 degrees and the mean limb length discrepancy was 0.5±4 mm.

 In four (33%) THAs, the piriformis muscles were resected and repaired. In all of the HAs, the piriformis and conjoint tendons were preserved.

Conclusion: The piriformis muscles were resected in some THAs, but the short rotators muscles were preserved in the HA procedures.

Introduction: Although posterior soft tissue repair reduces the incidence of dislocation after posterior-approach total hip arthroplasty (THA), little is known about the importance of tendon repair of the obturator externus muscle. This study makes a comparison for dislocation rates after the posterior-approach THA in two different procedures for short external rotators fixation.

Methods: We retrospectively reviewed 725 patients who underwent primary THAs via the posterior approach. In 541 patients we detached the piriformis muscle and the conjoined tendon from the greater trochanter backed with the capsule, and repaired to the posterior margin of the gluteus medius muscle (Group A). In this series the obturator externus muscle was cut with capsule incision far from the insertion at the greater trochanter, so we were unable to repair it effectively. In another 184 patients we released all external rotators (including the obturator externus muscle) from the insertion backed with the capsule in an L-shaped incision along the superior part of femoral neck and the trochanteric crest. The L-shaped flap was repaired back to the superior capsule and the posterior margin of the gluteus medius muscle (Group B). In each group we used two different head size (28 mm and 36 mm) according to the operation period and the cup size. We compared the dislocation rate between two groups at least one year after the operation. We also made a comparison for the dislocation rate in different head size within the two groups.

Results: The overall dislocation rate was 5.7% in Group A and 1.1% in Group B, respectively. The dislocation rate with the 28 mm head size was 6.9% and 3.1%, and with the 36 mm head size was 1.7% and 0%, for Groups A and B respectively.

Conclusions: The obturator externus muscle plays an important role in preventing posterior dislocation after THA. Anatomically it runs from the obturator foramen to the greater trochanter passing the posteroinferior part of the capsule like a sling. It gives dynamic pressure on the femoral head especially in flexion and during internal rotation in the natural hip. This function can be now be reproduced after THA as we have demonstrated, which gives low rates of dislocation.

Objective: The Larsen grade is widely used to assess large joint destruction in patients with rheumatoid arthritis (RA). In this method, various changes might be included within a single grade. 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) can visualize the disease activity in large joints affected by RA. The purpose of this study was to investigate the associations between the destruction of large joints in RA and FDG-PET/CT findings using a new radiographic evaluation method: the Assessment of Rheumatoid Arthritis by Scoring of large joint destruction and Healing in radiographic Imaging (ARASHI) scoring system.

Methods: Seventeen patients with RA (male, n=3; female, n=14) were enrolled in the present study. A total of 170 large joints (shoulder, elbow, hip, knee and ankle) were assessed. FDG-PET/CT was performed at the initiation of tumor necrosis factor inhibitor treatment. The extent of FDG uptake of the large joints was analyzed using the maximum standardized uptake value (SUVmax). Radiographs of the 10 large joints were obtained for each patient at baseline and after three years of treatment and were assessed according to the ARASHI score. A logistic regression analysis was performed to determine factors that predicted large joint destruction in these patients with RA.

Results: Radiographic progression of joint damage was detected in 26 joints by the Larsen grade and in 77 joints by the ARASHI score. The ARASHI status score was significantly correlated with the Larsen grade (R=0.92, P<0.001). A logistic regression analysis revealed that the ARASHI status score and the SUVmax at baseline were factors that showed the greatest association with large joint destruction at three years.

Conclusion: The ARASHI score may allow for a more detailed assessment of large joints than the Larsen method. Large joint destruction is likely to have progressed at three years in large joints with a high ARASHI status score and a high SUVmax at the initiation of biologic treatment.

Objective: We created a low-concentration brachial plexus block (LCBB) technique in which only the sensory modality is blocked, and intraoperative active motion is enabled. This study aimed to evaluate the effectiveness of this technique.

Methods: Six patients with a mean age of 71.3 years underwent surgery by the LCBB technique. Three patients had osteoarthritis (OA) and three had rheumatoid arthritis (RA). One total wrist arthrodesis, one partial wrist arthrodesis, and four wrist arthroplasties (Sauve-Kapandji procedure) were performed with tendon reconstruction. Ultrasound-guided supraclavicular brachial plexus block with 30 mL of 0.06% ropivacaine was performed approximately 2 hours presurgery. Local anesthesia (LA) was administered if the analgesic effect was not sufficient intraoperatively. We investigated the waiting time after the LCBB technique to surgery (WT), total surgical time (ST), total tourniquet time of each surgery (total TT), each tourniquet time during a single surgery (TT), number of patients for whom LA was administered, and the total volume of LA that was administered.

Results: We assessed the intraoperative active motion and performed surgery in all patients. The mean WT was 131 min, mean ST was 177.6 min, mean total TT was 92.8 min, and mean TT was 69.6 min. LA administration was required in three patients, and the mean volume of LA was 15.6 mL

Conclusion: Operating on a subcutaneous tendon rupture caused by OA or RA often requires additional bone and joint surgery, such as arthroplasty, for tendon reconstruction. However, intraoperative active motion during tendon suturing is difficult to perform with Bier block or wide-awake surgery. In all cases in which performing Bier block or wide-awake surgery was considered difficult, intraoperative active motion could be assessed by the LCBB technique. Therefore, this study supports the effectiveness of the LCBB technique.

Objective: The clinical measurement of range of motion (ROM) is a fundamental evaluation procedure of physical function. In this study, we investigated the reliability of a new ROM measurement with a non-contact three-dimensional (3-D) surface scanner.

Methods: Measurement objects were the active ROM of right elbow joints and ankle joints of eight healthy adults. We measured the ROM with two procedures. One was manual ROM measurement by six physical therapists (PT) with a goniometer. Another was a new ROM measurement, producing 3-D images of the joints with a 3-D surface scanner, which were measured by six doctors. We compared the two measurement procedures and analyzed inter-rater reliability with the intraclass correlation coefficient (ICC) and measurement time with the Mann-Whitney U test (MWUT).

Results: ICC (3,1) were 0.66 and 0.80 at elbow flexion, 0.35 and 0.80 at elbow extension, 0.39 and 0.85 at ankle extension, and 0.49 and 0.88 at ankle flexion with manual measurement and with 3-D scanner image measurement, respectively. The inter-rater reliability of the 3-D scanner image measurements was higher than the manual measurements at both joints. It took significantly longer time for the measurement with the 3-D scanner (176.0±63.3 seconds) than with manual measurement (34.5±3.1 seconds) at the elbow joint (P<0.01, MWUT). Similarly, it took a significantly longer time for the measurement with the 3-D scanner (213.6±55.4 seconds) than with manual measurement (58.2±4.8 seconds) at the ankle joint (P<0.01, MWUT).

Conclusion: ROM measurement with a 3-D scanner was a more reliable procedure than manual ROM measurement. However, it was not nearly as fast as manual measurement. Examiners must become familiar with the technique in order to shorten measurement time. The non-contact 3-D surface scanner is a very useful tool, and in the future, it can be applied not only to ROM measurement, but also to three-dimensional and sequential evaluations of joint deformation in patients with rheumatoid arthritis.