There are three representative international treatment guidelines for osteoarthritis (OA), each of which has different characteristics. These include the Osteoarthritis Research Society International (OARSI), the National Institute for Health and Clinical Excellence (NICE) from the National Health Service in the United Kingdom, and the American Academy for Orthopaedic Surgeons (AAOS). Among them, the OARSI guidelines are the most frequently revised with new evidence. Besides these international guidelines created by Western countries, there are Japanese OA treatment guidelines which were created by the Japanese Orthopaedic Association based on the OARSI guidelines (part Ⅱ). In some aspects, both guidelines are very similar. However, there are substantial differences, especially with respect to hyaluronic acid injection and supplements including glucosamine and chondroitin sulfate. In this paper, the newest 2014 OARSI treatment guidelines (part Ⅳ) are introduced in which the Author was a committee member as the Asian representative. There is also discussion about the present status of OA treatment in Western and Asian countries, especially when comparing between corticosteroid and hyaluronan intraarticular injections, and that between non-selective non-steroidal anti-inflammatory drugs (NSAIDs) and cyclooxygenase-2 inhibitors, and the recent status of acetaminophen and topical NSAIDs.

View full abstract

Objective: The purpose of this study was to evaluate the accuracy of placement of implants for total hip arthroplasty (THA), which were measured by computed tomography (CT) with an ultrasound-based navigation (USBN) system.
Methods: CT evaluations were performed in 44 patients who underwent THA with USBN. The mean age at surgery was 67 years. All surgeries were performed in the supine position with the direct anterior approach. The OrthoPilot^® imageless navigation system was used intraoperatively. Evaluation of the cup inclination angle (CIA), cup anteversion angle (CAA), and stem antetorsion angle (SAA) was carried out. Instead of SAA, the navigation system indicates the rasp antetorsion angle during surgery. The accuracy of the imageless navigation system was evaluated by comparison of the navigation values obtained intraoperatively with the CT measured values.
Results: The mean CIA was 39.6±4.1° (mean±sd) and the CAA was 18.5±6.1° in anterior pelvic plane with CT evaluation. USBN showed 39.0±3.2° in CIA and 18.8±5.9° in CAA intraoperatively. The mean absolute difference in CIA and CAA between navigation and CT was 2.4±2.1° and 2.2±2.7°, respectively. USBN showed a similar accuracy of placement of the cup compared to the reported accuracy with CT-based navigation. The rasp antetorsion angle was 28.6±10.0° and the mean SAA was 28.8±9.3°. A strong correlation was found between the rasp antetorsion angle and SAA (r²=0.737).
Conclusion: CT-free navigation has a definite advantage because of its easy method of pelvic and femoral registration, and no need for special preparation for surgery compared with CT or image-based navigation. USBN is a useful tool for performing accurate surgery for THA.

View full abstract

Objective: Computer-assisted surgery systems improve alignment accuracy in total knee arthroplasty (TKA) but they are expensive and time-consuming and thus, unpopular. Recently, a portable navigation system has shown excellent performance. We examined the accuracy of distal femoral cutting using an accelerometer-based portable navigation device (KneeAlign^® 2; OrthAlign Inc., Aliso Viejo, CA, USA) during TKA.
Methods: We included patients consisting of 78 knees with osteoarthritis, who had undergone TKA using the portable navigation KneeAlign^® 2 system. Computed tomography for each lower extremity was performed preoperatively. We simulated the TKA components’ position by using the preoperative planning software Athena^® (Soft Cube, Osaka, Japan), and we measured the flexion angle of the femoral component relative to the femoral mechanical axis in the sagittal plane. We performed osteotomy of the distal femur perpendicular to the femoral mechanical axis in the coronal plane and osteotomy of the distal femur using the measured flexion angle of the femoral component relative to the femoral mechanical axis in the sagittal plane.
Results: In all, 93.6% knees had a femoral component alignment within 3°perpendicular to the femoral mechanical axis.
Conclusions: The femur and tibia should be cut perpendicular to the mechanical axis on the coronal plane in TKA. Varus-valgus alignment of more or equal to 3°increased the incidence of component loosening. The portable navigation device ensured an accurate performance of femoral osteotomy in the coronal plane as that performed using other navigation systems. With regard to sagittal plane alignment, the flexion angle between the distal femoral anatomical axis and the mechanical axis showed large interindividual variations and this was measured beforehand using Athena^®, and which was confirmed intraoperatively. However, this alignment was primarily achieved visually using the anterior femoral cortex intraoperatively via the conventional method without using a navigation system. Thus, a portable navigation device is useful when performing surgery according to a predetermined plan.

View full abstract

Objective: In total knee arthroplasty, most of the femoral components should be placed perpendicular to the mechanical axis of the femur in the coronal plane. However, in the sagittal plane, a suitable flexion angle from the mechanical axis is unknown. Although determining the center of the femoral head and mechanical axis is possible by navigation systems used intraoperatively, the position of the cutting block depends on the surgeon’s preference. Planning the flexion angle of the femoral component from the mechanical axis is necessary preoperatively. We measured the angle between the mechanical axis and anatomical axis of the distal femur in the sagittal plane using three-dimensional imaging.
Methods: Sixty-seven femurs of patients with knee osteoarthritis were examined by computed tomography preoperatively, and the data were transferred into three-dimensional images by preoperative planning software. The coronal plane of each femur was defined by the femoral head center and the surgical epicondylar axis. The sagittal plane was orthogonal to the coronal plane. The angle between the mechanical axis and distal femoral axis in the sagittal plane (flexion angle) was then measured. The shape of each femur with large and small flexion angles was observed.
Results: The mean flexion angle was 3.1°±1.6° (range, 0° to 7.4°). At the extremes of the measured angles, the femur with 0°flexion angle had a linear shaft, and the femur with 7.4°flexion angle had severe bowing.
Conclusion: The angle between the mechanical axis and anatomical axis of the femur in the sagittal plane was 3.1°±1.6°. It is suggested that the flexion angle is related to bowing of the femur.

View full abstract

Objective: We analyzed the posterior condylar offset (PCO) and the postoperative flexion angle in two prostheses often used for total knee arthroplasty (TKA) using the “pre-cut trial” technique.
Methods: The “pre-cut trial” technique is based on a measured resection technique for distal femoral cutting and step-by step fitting for posterior femoral cutting to obtain a proper flexion gap and/or femoral rotational alignment. A total of 149 knees (FINE^® Total Knee System CR: 69 knees, LCS^® Complete^TM Knee System: 80 knees), on which TKA was performed from January 2012 through March 2013, were evaluated for the range of motion (ROM) and improvement rate of the ROM before and at 3, 6, and 12 months after surgery. In addition, we examined the relationship between the PCO ratio (division of PCO by the maximum anterior to posterior diameter of the distal femur) and the ROM.
Results: The mean flexion angles in the FINE^® and LCS^® knee systems were 114.7°and 117.8°before, and 124.8°and 123.6°one year after surgery, respectively. The improvement rates were 112.5% and 111.6%, respectively, one year after surgery. The preoperative PCO ratios in the FINE^® and LCS^® knee systems were 0.49±0.04 and 0.47±0.04, and the postoperative rate was 0.49±0.03 in both systems, without a significant change in both prostheses before and after surgery. The improvement rate of the flexion angle did not correlate with the PCO ratio before or after surgery (R<0.3). Furthermore, there was no clear correlation between the posterior tibial slope and the postoperative flexion angle (R<0.3). Conversely, there was a correlation between preoperative and postoperative flexion angles, as reported in previous studies.
Conclusion: There appeared to be no clear relationship between the ROM and PCO in the two prostheses when TKA was performed using the “pre-cut trial” technique that could suppress a PCO reduction and ensure consistency.

View full abstract

Objective: When the extension gap is smaller than the flexion gap during total knee arthroplasty (TKA), an additional osteotomy of the distal femur is needed, which results in joint line elevation. We hypothesized that the chief cause of a decrease in the extension gap is excessive tension of both the medial collateral ligament and posteromedial capsule during knee extension. Therefore, we introduced a new technique called the “posteromedial-longitudinal capsulotomy” (PMLC) in May 2013 that allowed the separation of the medial collateral ligament from the posteromedial capsule, making it possible to expand the extension gap selectively. Our objective in this study was to assess the relationship between PMLC and the joint line in total knee arthroplasty.
Methods: We compared two groups: Group A (70 patients, 85 knees) who underwent TKA before May 2013 prior to the introduction of PMLC, and Group B (77 patients, 91 knees) who underwent TKA after its introduction after May 2013. The posterior cruciate ligament was preserved in all patients. We evaluated the joint line based on differences in thickness between the surgically removed femoral bone and femoral components. We adjusted the thickness of the bone saw accordingly.
Results: Expansion of the extension gap was needed in 66 of the 85 Group A knees (78%) and in 75 of the 91 Group B knees (82%), respectively. The technique for expansion in Group A was additional distal femoral osteotomy in 20 cases and other soft tissue release in 46 cases. In Group B there was additional distal femoral osteotomy in 14 cases and PMLC in 61 cases. The amount of distal osteotomy was 2.9 mm in Group A and 1.1 mm in Group B, which was significantly smaller. The amount of differences in the joint line was 0.9±3.2 mm (medial) and 1.6±2.6 mm (lateral) in Group A and −0.4±2.2 mm (medial) and 0.6±1.9 mm (lateral) in Group B, respectively.
Conclusion: PMLC significantly reduces the amount of osteotomy required in TKA, and makes it possible to control elevation of the joint line.

View full abstract

Objective: Revision surgery is one of the most serious complications after total knee arthroplasty (TKA). Revision TKA (rTKA) is very complicated and its clinical results are generally inadequate. Reports of the outcome of such revisions is rare in Japan. We herein report our results of rTKA.
Methods: Twenty patients (17 female and 3 male) who received rTKA were included in this analysis. The mean age at rTKA was 70 years (36-84 years), and the mean follow-up period was 50.1 months (range, 5-134 months). The underlying diseases were osteoarthritis in 13 patients, rheumatoid arthritis in five patients, and osteosarcoma in two patients, respectively. The period from primary TKA to rTKA and the cause of implant failure were investigated. Japanese Orthopaedic Association (JOA) osteoarthritis knee score, range of motion (ROM), Knee Society Score (KSS) clinical and function, Japanese Knee injury Osteoarthritis Outcome Score (J-KOOS), and patients’ satisfaction were evaluated. The relations between patients’ satisfaction and clinical results were examined using Spearman’s rank-order correlation.
Results: The average period between primary TKA and rTKA was 90.9 months (range, 3-320 months). The reasons for implant failure included loosening in six patients, infection in four patients, pain in three patients, wear in three patients, implant breakage in two patients, periprosthetic fracture in one patient, and instability in one patient. The JOA score was 45.3 points (range, 20-80 points) preoperatively and 64 points (range, 45-85 points) postoperatively. ROM was improved from −5.7-100° to −3.7-103°. Postoperative KSS clinical was 84.5 points (range, 30-100 points) and function was 58.6 points (range, 20-90 points). The average J-KOOS total was 58.4 (range, 20.2-80.4). 73.3% of patients were satisfied with the result of their rTKAs. The clinical score significantly related with patients’ satisfaction were quantity of flexion improvement, postoperative KSS clinical score, postoperative J-KOOS total, and postoperative J-KOOS subscale; activity of daily life.
Conclusion: The cause and clinical results of our cohort of patients who underwent rTKA were very similar to past reports. However, there are few reports of patients’ satisfaction after rTKA, and to our knowledge there have been no other well-organized studies like this. Patients in our study had a high degree of satisfaction after rTKA.

View full abstract

 Anticoagulant medications have been widely used as prophylactic agents against deep vein thrombosis (DVT) in total knee arthroplasty. Yet, there are more factors we may need to consider when using such interventions including: drug selection, starting time, duration of administration and judgment of therapeutic effectiveness. In this study, we used enoxaparin sodium for prophylaxis of DVT, and examined the incidence rates of DVT from the time of commencing the drug administration.

View full abstract

Objective: To assess the prevalence of osteoporosis (OP) in patients with osteoarthritis (OA) undergoing total knee arthroplasty (TKA) or total hip arthroplasty (THA).
Methods: In patients with OA undergoing TKA or THA, plain radiographs of thoracic and lumbar spine were examined for the presence of vertebral fracture (VFx) between T4-L5, using the semiquantative method advocated by Genant et al. Lumbar spine and femoral bone mineral density (BMD) were measured using dual-energy X-ray absorptiometry. OP 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.
Results: The prevalence of VFx in patients with OA undergoing THA in the 4^th or less, 5^th, 6^th, 7^th, or 8^th decade of life and beyond were 0%, 10.0%, 14.3%, 15.4% and 25.0% for men, and 0%, 5.8%, 21.6%, 23.9% and 35.0% for women, respectively. The prevalence of VFx in patients with OA undergoing TKA for the same age groups were 0%, 0%, 0%, 0% and 16.7% for men, and 0%, 0%, 5.9%, 10.4% and 11.8% for women, respectively. The prevalence of OP of the lumbar spine in patients with OA undergoing THA in the same age groups were 0%, 0%, 0%, 11.0% and 0% for men, and 0%, 3.3%, 6.0%, 7.3% and 11.8% for women, respectively. The prevalence of OP of the lumbar spine in patients with OA undergoing TKA in the same age groups were 0%, 0%, 25.0%, 0% and 0% for men, and 0%, 0%, 0%, 6.1% and 9.1% for women, respectively. The prevalence of OP at femoral neck in patients with OA undergoing THA in the same age groups were 0%, 0%, 0%, 11.0% and 0% for men, and 0%, 1.9%, 10.5%, 25.6% and 46.2% for women, respectively. The prevalence of OP at femoral neck in patients with OA undergoing TKA in the same age groups were 0%, 0%, 0%, 0% and 25.0% for men, and 0%, 0%, 0%, 18.8% and 22.2% for women, respectively.
Conclusion: The following pattern was observed in patients with OA undergoing TKA or THA: Firstly, the prevalence of VFx tended to be higher in women than in men. Secondly, the prevalence of VFx tended to be higher with increasing age in both genders. Lastly, the prevalence of OP tended to be greater in BMD at the femoral neck than at the lumbar spine.

View full abstract

Objective: To confirm the efficacy of combination therapy with conventional synthetic disease modifying anti-rheumatic drugs (csDMARDs) in patients with rheumatoid arthritis (RA) in our institute.
Methods: From medical records, csDMARD use in 797 patients with RA was analysed retrospectively
Results: Forty-three (5.1%) out of 797 patients were treated with combination therapy at the time of the study. Twenty, eight and 15 patients were either in remission, had low disease activity or had moderate disease activity, respectively. Sixty-three combination therapy cases were discontinued for 54 (6.8%) patients because three were in remission, 49 had insufficient response, eight experienced adverse effects, and three cases were pregnant. Out of the 49 cases with an insufficient response, 18 cases (37%) started treatment with biologics. The most frequent combination of csDMARDs was methotrexate (MTX) plus tacrolimus (TAC) and 18 (56.3%) out of 32 cases continued the MTX-TAC combination therapy.
Discussion: According to a literature review, most csDMARD combinations include hydroxychloroquine that is unavailable in Japan, and the maximum doses of MTX and salazosulfapyridine are higher than those permitted in Japan under domestic regulations. In the study of the MTX-TAC combination the therapy could be continued with a lower-dose of additive TAC.
Conclusion: Considering csDMARDs and their dosages currently available in Japan, only few evidence based combination therapies with csDMARDs have been adopted. Sufficient doses of csDMARDs should be used to obtain the maximum benefit from the combination therapies. In this retrospective analysis, MTX and low-dose TAC appears to be a potent combination for the treatment of RA.

View full abstract

 We treated a case of synovial osteochondromatosis in the right knee posterior septum using arthroscopy with a posterior trans-septal approach. The patient was a 64-year old female who complained of discomfort and pain upon flexion and extension, with restricted range of motion (ROM). X-ray and computed tomography imaging revealed several osteochondromas at the posterior compartment of the knee. The patient was diagnosed with osteochondromatosis of the right knee, and an arthroscopic examination was performed. Briefly, we made a posteromedial portal for arthroscopic observation by passing the arthroscope between the posterior cruciate ligament and intercondylar notch. After dissection of the posterior septum from the posteromedial portal, we created a posterolateral portal. By observation and operation from the posteromedial and posterolateral portals, osteochondromas at the posterior septum and posterior compartment of the knee were removed effectively. At a 12-month follow-up, the patient was pain-free with a full ROM. It is difficult to remove osteochondromas at the posterior compartment of the knee through the conventional anteromedial and anterolateral portals. However, a posterior trans-septal approach may be an easier way to undertake such challenging surgery.

View full abstract