Periprosthetic joint infection (PJI) is now one of the most challenging complications in orthopaedic surgery. There are many surgical site infection (SSI) prevention guidelines that have recently been introduced. Among them, the International Consensus on PJI is one of the most outstanding guidelines. It has provided the global standard since 2013 for 204 of the most clinically relevant questions in PJI care. It is still the most informative literature for PJI prevention, diagnosis and treatment.

 But, there are some disagreements among several recent SSI prevention guidelines. These differences are mainly due to the timing when the guidelines were made, the sources of the evidence, and the approach used to finalize each statement.

 In Japan, there are several well organized domestic guidelines for SSI prevention. Among them, the Japan Orthopaedic Association guideline is one of the most organized materials covering many clinically relevant topics. The guideline was made in a similar fashion to the International Consensus, but it contains slightly different questions and references.

 In this review, the most important messages recommended in these two guidelines have been summarized regarding the evidence of the operative environment for prevention of SSI in orthopaedic surgery.

 Bacteremia occurs through the translocation of oral bacteria from subgingival biofilms into the systemic circulation following daily oral hygiene activities and dental procedures. Bacteremia is caused more frequently in the treatment of periodontal disease than in other dental procedures. Periodontal treatment involves mechanical debridement, which consists of plaque control, scaling and root planing, and periodontal surgery. The debridement of bacterial biofilms in close proximity to the ulcerated epithelium of the gingival sulcus or periodontal pocket may lead to bacteremia. Therefore, it is essential to maintain oral hygiene and periodontal health in order to decrease the risk of bacteremia.

 It has long been debated by the American Academy of Orthopaedic Surgeons (AAOS) and the American Dental Association (ADA) whether or not the risk of prosthetic joint infection (PJI) is related to bacteremia after professional dental treatments. Currently, there is strong evidence of such an association. In addition, the indirect evidence obtained from multiple moderate-strength studies suggests that the use of prophylactic antibiotics reduces the incidence of post-dental procedure bacteremia. However, there have been no studies regarding the relationship between bacteremia and PJI.

 In summary, it is necessary to consider the risk of dental procedure-induced bacteremia and patient characteristics when prescribing prophylactic antibiotics for patients with prosthetic joints who are undergoing dental procedures. It may be particularly beneficial for these patients to maintain good oral hygiene.

Objective: To examine the mid-term results of transtrochanteric anterior rotational osteotomy (ARO) for subchondral insufficiency fracture of the femoral head (SIF) in young adults.

Methods: We reviewed 10 hips in nine young patients who underwent ARO for SIF between 2000 and 2016 (mean age 25 years, 7 males; 2 females). The mean follow-up duration was 4.4 (2.0-10.8) years. Clinicoradiological assessments were performed using the Japan Orthopaedic Association (JOA) score and sequential radiographs.

Results: All of the 10 hips had survived at the final follow-up. The mean preoperative JOA score was 61.3 (range, 41 to 76), which significantly improved to 96.5 (range, 88 to 100) at the final follow-up. A mean postoperative intact ratio (intact area of the femoral head/weight-bearing area of the acetabulum) of 93% was achieved with a mean femoral neck-shaft varus angle of 11° (range, 3.0 to 18°). No hips showed postoperative progression of collapse at the anteriorly rotated fractured lesion.

Conclusion: The results of current cases suggest that ARO should be considered as a surgical option for SIF in young adults.

Background: In total hip arthroplasty (THA), postoperative pain control affects patient recovery and satisfaction. Periarticular injection with a multimodal protocol has been reported to be effective for pain control. There have been few studies describing only single periarticular injection using various kinds of medications for THA. In this study, we assessed the efficacy of single periarticular injection compared with epidural infusion on postoperative pain and analgesic requirements after THA.

Methods: Forty-three patients were randomized into two groups to receive either intraoperative single periarticular injection with ropivacaine, morphine, epinephrine, methylprednisolone, ketoprofen, and saline (Cocktail group), or continuous epidural infusion for three days postoperatively (Epidural group). For rescue analgesia, intravenous patient-controlled analgesia with morphine was used for 24 hours postoperatively. The intensity of hip pain (0-100 mm on visual analog scale (VAS), for 1 to 21 days postoperatively), morphine requirements (for 24 hours), and satisfaction (0-100 mm on VAS, for 1 to 21 days postoperatively), were recorded.

Results: VAS for pain at rest was lower in the Cocktail group than in Epidural group on postoperative day (POD) 1, which was statistically significant (7.5 vs 17.8, P<0.05). On POD 2, POD 3, POD 5 and POD 7, the VAS in the Cocktail group was lower, but the differences were not statistically significant (P=0.215, 0.357, 0.140 and 0.133, respectively). After that, and up to POD 21, there was no further statistical difference of VAS for pain between the two groups. Morphine usage during the first 24 hours was lower in the Cocktail group compared to the Epidural group (0.24 vs 0.39 mg, P<0.05). The VAS for satisfaction was generally higher in the Cocktail group, but there was no statistical difference between the two groups.

Conclusions: Periarticular injection with multimodal medications provided superior pain relief and reduced morphine consumption compared with continuous epidural infusion after THA.

Introduction: No studies have evaluated the clinical utility of remnant preservation after anatomic double-bundle anterior cruciate ligament (ACL) reconstruction. The study hypotheses were as follows: (1) Subjective and functional clinical results may be comparable between anatomic double-bundle reconstructions that preserve the remnant tissue and those that resect the remnant tissue, (2) postoperative knee stability and the second-look arthroscopic evaluation may be significantly more favorable with the remnant preserving reconstruction, and (3) the degree of the initial graft coverage may significantly affect postoperative knee stability.

Methods: A total of 179 patients underwent anatomic double-bundle ACL reconstruction. Based on the Crain classification of ACL remnant tissue, 81 patients underwent the remnant-preserving procedure (group P) and the remaining 98 patients underwent the remnant-resecting procedure (group R). The patients were followed for two years or more.

Results: The subjective and functional clinical results were comparable between the two reconstruction procedures. Side-to-side anterior laxity was significantly less (P=0.0277) in group P (0.9 mm) than in group R (1.5 mm). During arthroscopic observations, results for group P were significantly better than for group R concerning postoperative laceration and fibrous tissue coverage of the grafts (P=0.0479).

Conclusion: Remnant preservation in anatomic double-bundle ACL reconstruction did not significantly improve subjective and functional results in the short-term evaluation, but it significantly improved postoperative knee stability. The degree of initial graft coverage significantly affected postoperative knee stability.

Objective: Allogeneic blood transfusion has inherent risks of infection and allergic reactions. We investigated the efficacy of intraoperative autologous blood transfusion during total hip arthroplasty (THA).

Methods: We analyzed 140 patients who underwent primary THA for osteoarthritis or idiopathic osteonecrosis. We compared 106 patients who received intraoperative autologous blood transfusion (group A) and 34 patients who did not (group B). No statistically significant differences were found between the two groups in respect of sex, age, and diagnosis. We investigated the changes of hemoglobin and hematocrit, intraoperative and postoperative blood loss, allogeneic blood transfusion, and complications.

Results: The mean preoperative hematocrit was significantly different between the groups: 38.9±4.3% for group A and 40.8±3.7% for group B (P<0.05). The mean preoperative hemoglobin was not significantly different between the groups: 13.1±1.6 g/dL for group A and 13.7±1.5 g/dL for group B (P=0.12), respectively.

 The differences between preoperative and lowest values of hematocrit and hemoglobin were 11.6±3.4% and 4.1±1.2 g/dL for group A, respectively, and 14.1±4.3% and 4.8±1.4 g/dL for group B, respectively. The differences between the two groups were significant (P<0.05). Intraoperative and postoperative blood loss were similar between the two groups. The number of patients who required allogeneic blood transfusion was eight (7.5%) for group A and three (8.8%) for group B. No patient developed early deep infection or sepsis postoperatively. One patient in both group A and B developed deep vein thrombosis.

Conclusion: The ratio of patients requiring allogeneic blood transfusion was not significantly different between the two groups. This can be explained because group A had a higher proportion of patients with anemia preoperatively. Intraoperative autologous blood transfusion in THA slowed the decrease of hematocrit and hemoglobin, and may reduce the need for allogeneic blood transfusion.

Objective: To assess the association between muscle volume of lower limbs and forearm bone mineral density (BMD) in a population with knee osteoarthritis (OA).

Methods: A total of 682 women (average age: 55.7±15.0 years old) who participated in the Iwaki Health Promotion Project 2015 were recruited. Radiographs of both knee joints were evaluated by Kellgren-Lawrence (KL) grade and those with KL grade 2 or more in severity were defined as OA of the knee. A total of 107 women (average age: 70.2±7.5 years old) who had bilateral OA of the knee were recruited as the study subjects. The muscle volume of each lower limb was measured by a digital composition analyzer, and it was calculated by the summed value of both legs (kg). BMD of the forearm (g/cm²) was measured by dual-energy X-ray absorptiometry at the radius of the non-dominant hand. BMD was evaluated by the region of interest at 1/3 of the distal radius. Knee symptoms were evaluated by the Knee injury and Osteoarthritis Outcome Score (KOOS) Pain scale. Multiple regression analysis was conducted with muscle volume of the lower limbs as dependent variable, and age, height, weight, KL grade, prevalence of menopause, KOOS pain, and BMD as independent variables.

Results: The mean value of muscle volume and BMD in subjects was 11.6±1.4 kg and 0.51±0.08 g/cm², respectively. In a multiple regression model, BMD was significantly associated with muscle volume of the lower limbs (B=2.531; β=0.142; P=0.019).

Conclusion: BMD correlated with muscle volume of the lower limbs in an elderly population with radiographic bilateral OA of the knee.

Background: To perform a medial open-wedge high tibial osteotomy (OWHTO), surgeons frequently expose the medial-proximal tibia by partial or complete distal release of the overlying insertion of the superficial layer of the medial collateral ligament (sMCL). Biomechanically, the sMCL is the primary restraint to valgus forces. Therefore, any release of the sMCL can lead to valgus instability of the knee joint. The purpose of this study was to clarify the valgus instability after the release of the distal attachment of the sMCL in OWHTO.

Methods: Between 2009 and 2015, 84 consecutive patients (93 knees) who underwent OWHTO using a locking plate were enrolled in this study. There were 19 men and 65 women with a mean age of 60 years (range; 20 to 78 years) at the time of surgery. We performed the complete release of the distal attachment of the sMCL. Then, a biplanar osteotomy of the tibia was performed. A beta-TCP spacer was implanted in the opening space. Then, a locking plate was implanted onto the tibia. All patients underwent clinical and radiological examinations preoperatively and at one year postoperatively. To assess objective medial instability, joint line convergence angle (JLCA) and the medial joint space (MJS) were evaluated.

Results: Postoperatively, the mean Japan Orthopaedic Association score significantly improved from 69 to 90 points (total score: 100 points, P<0.0001). The JLCA and MJS significantly increased immediately after the release of the distal attachment of the sMCL intraoperatively (6.7° and 11.4 mm, P<0.0001). However, there were no significant differences in the JLCA and MJS between preoperative (0.4° and 6.7 mm) and one-year postoperative evaluations (0.4° and 6.3 mm).

Conclusion: The complete release of the sMCL did not cause postoperative valgus instability at one year after OWHTO procedure.

Objective: Accurate rotational alignment in total knee arthroplasty (TKA) is essential for successful outcomes. The Akagi’s line, which connects the middle of the posterior cruciate ligament and the medial border of the patellar tendon attachment, is widely recognized as a reliable reference axis indicating the anteroposterior orientation of the tibia. The aim of this prospective study was to investigate the accuracy of intraoperative identification of the Akagi’s line in TKA.

Methods: Twenty-two patients with knee osteoarthritis were enrolled in this prospective study. Preoperative computed tomography (CT) scans were performed to identify the Akagi’s line. The line was incorporated in the CT-based navigation system and defined as CT-Akagi’s line. Two observers (observer A/B) determined the Akagi’s line manually (M-Akagi’s line) without referring to navigation before or after the proximal tibial cut. The angle between CT-Akagi’s line and M-Akagi’s line and the outlier of the angle were investigated.

Results: The angles between CT-Akagi’s line and M-Akagi’s line for observer A was 2.5°, and for observer B was −0.1° preoperatively, and those for observer A was 1.1° and for observer B was −3.1° postoperatively. The rate of outliers for observer A was 23%, and for observer B was 18% preoperatively, and that for observer A was 18%, and for observer B was 23%, postoperatively.

Conclusion: Although the manual identification of Akagi’s line is generally consistent, it is still necessary to recognize possible outliers.

Objective: Improving wear and oxidation resistance has been recognized as the key task to achieve longer-term implant survival in vivo. Beta-sterilization is a unique sterilization method of B. Braun Aesculap and it has the potential to prevent oxidation because the process is completed in short time as compared to gamma-sterilization. In this study, we investigated the oxidative degradation of retrieved conventional tibial inserts using Fourier Transform Infra-red Spectroscopy (FT-IR) and Raman spectroscopy (RS).

Materials and Methods: We analyzed 12 retrieved and three unused tibial inserts made of beta-sterilized conventional ultra-high-molecular-weight polyethylene. The average in vivo time was 33.6 months (0.7-94.6). We obtained microtomed sections from three locations: medial, lateral and non-load zones. We calculated in each section the maximum values and the profiles of oxidation index, lipid and crystallinity along the thickness by FT-IR and RS.

Results: Increases of maximum oxidation index, lipid and crystallinity were observed in all the retrieved samples as compared with the unused samples; each parameter correlated with in vivo time in both load zones. Furthermore, the maximum oxidation index showed strong correlation with maximum crystallinity and maximum lipid. We observed the white band at the depth of 2-3 mm from the bearing surface in most of the slices obtained from the mid-term retrievals.

Conclusion: Our results show that oxidative degradation occurred in beta-sterilized polyethylene after in vivo exposure and the crystallinity increased along with the extent of oxidation. Lipid absorption was promoted in the contact area by the mechanical action of the femoral counterpart combined with mechanical stress, which exacerbated oxidative degradation. The free radicals generated during the process might trigger oxidative degradation close to the bearing surface in beta-sterilization, where a reduction of mechanical properties could cause delamination and wear damage.

Introduction: Finger involvement is highly prevalent in rheumatoid arthritis, and when deformity affects these fingers through joint destruction, it can markedly impact the activities of daily living. Progress in pharmacotherapy has dramatically improved disease activity control, but residual synovitis may still continue to affect the fingers of many patients. We previously reported that deformities and dysfunction progresses in such cases. However, no apparent correlations have been established between disease progression and disease activity. We therefore investigated how disease activity affected progression of finger deformity and dysfunction over time.

Methods: Between 2009 and 2015, we analyzed 37 patients with 63 hands affected by rheumatoid arthritis available for follow-up. Swan-neck deformity of the fingers were classified according to Nalebuff’s type classification. Boutonnière deformity of the fingers were classified according to Nalebuff’s stage classification. Hand function and upper extremity function was assessed based on a modified Kapandji index (MKI) and Disabilities of the Arm, Shoulder and Hand (DASH) score. Changes in disease activity from 2009 through 2015 were used to divide the patients into the following four groups: “improved”, “low disease activity maintained”, “high disease activity maintained”, and a “worsening” group.

Results: There were 22, 9, 16, and 16 hands in the improved, low disease activity maintained, high disease activity maintained, and worsening groups, respectively. Finger deformities progressed in all four groups with a statistically significant worsening observed in all groups, except for the low disease activity maintained group. MKI was only maintained in the low disease activity maintained group. DASH improvement during the study period was only seen in the low disease activity maintained and improved groups, while marked worsening was noted in the high disease activity maintained group and worsening group.

Discussion: Goals in treating rheumatoid arthritis include clinical, structural, and functional remission, but until now, it has been unknown whether pharmacotherapy would be effective in achieving the latter two forms of remission. This study clarifies that although finger deformity does progress regardless of disease activity control, finger function can be maintained by keeping disease activity low over the long term. With the use of appropriate pharmacotherapy, it is possible to achieve these treatment goals.

Conclusion: Physicians who treat rheumatoid disease must continue their efforts in daily clinical practice to preserve finger function by suppressing disease activity to as low as possible.

 Thumb carpometacarpal (CM) osteoarthritis is the one of the most common diseases in hand surgery. Various surgical procedures have been developed such as simple trapeziectomy, arthrodesis, ligament reconstruction tendon arthroplasty and implant arthroplasty. Recently, arthroscopic intervention was reported, and a new type of arthroplasty using suture button was proposed.

 From 2003 to 2012, we performed tendon suspension arthroplasty, which was developed by Watson. However, we experienced hyperextension deformity of the metacarpophalangeal (MP) joint postoperatively in several cases. MP joint hyperextension led not only to weakness of pinching power, but also to unacceptable appearances, especially in female patients. Therefore, since 2012, we have performed a new procedure which modified Watson’s procedure to prevent MP joint hyperextension. In this article, we summarize the historical perspective of surgical procedures for CM osteoarthritis, and we describe our new procedure and its results.

Introduction: Kashin-Beck disease (KBD) is a chronic disease which is mainly distributed in a limited endemic area from South-Eastern Siberia to North China. The most frequently involved joints are ankles, knees, wrists, and elbows. Symptoms are pain and limited motion of the affected joints. The main treatments for KBD are rehabilitation, osteotomy or total knee arthroplasty (TKA). We report our experience of a case in which simultaneous bilateral TKA for KBD of the knee was undertaken.

Case: A 75-year-old woman presented with a history of chronic bilateral knee pain. On a physical examination, the range of motion (ROM) of the knee was −5°/−5° in extension and 130°/130° in flexion. The Japan Orthopaedic Association (JOA) score was 40/40 points, Knee Score (KS) was 45/60 points, Function Score (FS) was five points and Functional Score for Adult Tibetans with Kashin-Beck Disease (FAST-KBD) was 24 points, respectively. On radiographic examination, Femorotibial angle (FTA) was 194°/189° with narrowing of the medial joint space, osteosclerosis and osteophyte formation were found. We diagnosed osteoarthritis with KBD, and the patient underwent simultaneous bilateral TKA (Smith & Nephew JOURNEY^TM Ⅱ BCS Bi-Cruciate Stabilized Knee System). At eight months postoperatively, ROM of the knee was 0°/0° in extension and 140°/140° in flexion. JOA score was 85/85 points, KS was 95/92 points, FS was 80 points and FAST-KBD was 39 points, respectively. The patient had relief of pain and she could walk without assistance.

Conclusion: Simultaneous bilateral TKA can be regarded as useful for the treatment of severe KBD of the knee, and it is associated with good clinical and radiographic outcomes, at least in short-term follow-up.