Comparison of different cementing techniques for cement penetration under tibial component in total knee arthroplasty: a retrospective observational study.

PURPOSE: This study aimed to investigate the differences in cement penetration between cementing techniques in total knee arthroplasty (TKA). MATERIALS AND METHODS: We retrospectively evaluated knee undergone TKA at our hospital for both preoperative and postoperative computed tomographic (CT) evaluations. Cementing was performed with hand mixing and hand packing (HM group) and with vacuum mixing and cement gun use (VM group). We measured the area under the tibial baseplate (sclerotic and nonsclerotic sides) and compared the mean and maximum depths of cement penetration at each area. RESULTS: Of the 44 knees evaluated, 20 and 24 knees were in the HM and VM groups, respectively. At the center of the sclerotic side, the mean penetration depths (2.0 ± 0.7 and 2.5 ± 0.7 mm, p = 0.02) and the maximum penetration depths (4.0 ± 0.9 and 5.0 ± 1.6 mm, p = 0.02) were significantly deeper in the VM group than in the HM group. The correlation between preoperative Hounsfield unit values and mean penetration were r = -0.617 (p < 0.01) and -0.373 (p = 0.01) in the HM and VM groups, respectively. CONCLUSION: The cementing technique of vacuum mixing and using a cement gun allowed for deeper cement penetration compared with the hand mixing and hand packing technique, even in bone sclerotic sites.

A case of septic arthritis of the elbow joint in rheumatoid arthritis diagnosed by arthroscopic synovectomy.

We report a case of methicillin-resistant Staphylococcus aureus (MRSA) septic arthritis of the elbow detected by arthroscopic synovectomy in an 81-year-old woman with rheumatoid arthritis (RA) who was initially diagnosed with a rheumatoid arthritis flare-up. The patient was administered abatacept, an antirheumatic biological agent, as the synovial fluid culture was negative. Destruction of the joint progressed despite medication, and the patient underwent arthroscopic synovectomy. MRSA was detected in the culture of the synovium that was collected intraoperatively, and septic arthritis was diagnosed. The infection subsided with anti-MRSA antibiotics, but the patient continued to experience moderate pain and limited motion. In RA patients, it might be difficult to differentiate minor findings from infection. Arthroscopic synovectomy is one of the selectable procedures that should be actively considered when infection is suspected.

Total knee arthroplasty in the past three decades: Trends in patient characteristics and implant survivorship.

OBJECTIVE: To explore the trends in patient characteristics and implant survivorship (IS) for primary total knee arthroplasty (TKA) over the past three decades. METHODS: This retrospective study enrolled a total of 635 knees who underwent TKA from 1985 to 2014. They were divided into three groups: group A, 125 knees in 1985-1994; group B, 203 knees in 1995-2004; and group C, 307 knees A in 2005-2014. The patient characteristics and IS were compared. RESULTS: The mean age of patients undergoing TKA was getting older: 65.3 ± 9.7, 69.1 ± 10.0, and 74.6 ± 8.4 years, in groups A, B, and C, respectively (p = .001). The proportion of patients <60 years old with RA decreased (p < .001), whereas that of patients ≥ 80 years old with OA increased dramatically, it was 7.0%, 14.5%, and 32.0% in groups A, B, and C, respectively (p < .001). The IS free from infection was over 98% in all groups. Alternatively, the IS free from aseptic loosening become better, it was 83.7%, 95.2%, and 98.2% in groups A, B, and C, respectively (p = .014). CONCLUSIONS: From these trends, we can estimate that the number of patients undergoing TKA will further increase in the future in an aging society.

Evaluation of infections in orthopedic patients using next-generation sequencing.

INTRODUCTION: Culture tests are used to diagnose infections, but there are various problems such as low sensitivity in detecting infections in orthopedic cases. To address this problem, next generation sequencing (NGS) analysis, which can comprehensively search for bacterial genes, is being applied clinically. In this study, we examined whether NGS analysis was useful in evaluating infections in orthopedic cases. METHODS: The participants were 23 patients suspected of having an infection between 2016 and 2017. Samples were collected from tissues suspected of being infected and were subjected to culture tests and NGS analysis, and the positive rates from the culture tests and from the NGS analysis were compared. We also attempted to determine cutoff value for the NGS analysis. RESULTS: A total of 20 cases were ultimately diagnosed as infections and 3 cases were diagnosed as non-infections. The sensitivity of the culture tests was 70%, and the sensitivity of the NGS analysis was 55%. When the NGS analysis was performed with the diversity index set to the cut-off value, the sensitivity was 75% for the Simpson index. In this study, the sensitivity was 90% when the analysis was performed using the NGS index, which is a combination of the diversity index and the OTUs (operational taxonomic units) value. CONCLUSION: NGS analysis using the NGS index showed excellent sensitivity and specificity compared to culture tests. NGS analysis is therefore a useful modality for assessing infections in orthopedic cases.

Rheumatoid Arthritis Onset from Shoulder Monoarthritis.

PURPOSE: To investigate the incidence and clinical characteristics of rheumatoid arthritis (RA) presenting with shoulder monoarthritis. PATIENTS AND METHODS: Our study included 113 patients (77 females; mean age, 63.0 ± 13.1 years) whom we newly diagnosed with RA in 2012-2016. We investigated cases with onset from shoulder monoarthritis. Specifically, we examined physical findings, blood test results, radiographic findings, magnetic resonance imaging (MRI) findings, and duration from initial visit to diagnosis. RA was diagnosed based on the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria. RESULTS: Overall, mean 2010 ACR/EULAR criteria score was 6.8 ± 1.8, and median duration to diagnosis was 3 days (interquartile range: 0-14). Two patients (1.8%) were identified as having RA with onset from shoulder monoarthritis. Both were late middle-aged women with MRI findings of rotator cuff tear and remarkable synovial proliferation. However, neither patient fulfilled the 2010 ACR/EULAR criteria. It took 85 and 98 days to make a definitive diagnosis, respectively. CONCLUSION: Early diagnosis is difficult when RA synovitis develops from shoulder monoarthritis, especially, in elderly patients who have a rotator cuff tear. In addition to MRI, culture-based and pathological examinations may be helpful for early diagnosis of RA.

A Simple Method to Reduce the Incidence of Cyclops Lesion after Anterior Cruciate Ligament Reconstruction.

The purpose of this study is to determine the influence of debridement in and around the bone tunnels on the prevalence of cyclops lesion (CL), after anterior cruciate ligament reconstruction (ACLR) with hamstring grafts. Our hypothesis was that bone tunnel debridement during ACLR would reduce the prevalence of CL. Methods for debridement in and around the bone tunnels after tunnel drilling were standardized and applied to 38 knees undergoing double-bundle ACLR between 2011 and 2014, Group A (debridement group). Group B (nondebridement group) included 56 knees in which bone tunnel debridement was not performed. Postoperative MRI was performed to evaluate the presence of CL and the following three criteria: (1) the intercondylar site of CL (grade 1-3), depending on its anterior extent along the femoral condyle; (2) posterior bowing of the ACL graft; and (3) the positional relationship between the frontmost fiber of ACL graft and Blumensaat's line. If CL caused loss of extension or pain or discomfort during knee extension, it was defined as symptomatic CL (SCL). CL was detected in 8 cases (21.1%) in Group A and 26 cases (46.4%) in Group B. The prevalence of CL was significantly lower in Group A than in Group B (p = 0.010), and the risk ratio of CL was 0.31 (95% confidence interval: 0.12-0.79). Furthermore, 10 patients in Group B had SCL, compared with none in Group A (p = 0.004). In Group A, the intercondylar site of CL was grade 1 in all cases, while in Group B, the CL grades were 1 (n = 17), 2 (n = 7), 3 (n = 2) (p = 0.008). There were no cases of posterior bowing of the ACL in Group A, but six cases in Group B (p = 0.023). Debridement in and around the bone tunnel is a simple and effective method of preventing CL and SCL after ACLR. The level of evidence for the study is 3.

Age-related changes in muscle elasticity around the shoulder joint in young male baseball players: A prospective longitudinal study.

BACKGROUND: Longitudinal changes of elasticity in the muscle tissues around the shoulder joint during the growth period have not been assessed using shear wave elastography. METHODS: This study enrolled male students aged 13-18 years who played baseball or rubber baseball as an extra-curricular activity during junior high or high school or on a baseball team outside of school. The exclusion criterion was a history of surgery for athletic injury. One hundred and twenty-one boys were included in the study. The elasticity of the superior part of the trapezius, the supraspinatus, and the infraspinatus were measured by ultrasound. The shear elastic modulus (SEM), which is the ratio of the strain ratio (SR) in the acoustic coupler to the SR of each muscle, was calculated as a representative value. Six months after the baseline assessment, subjects were evaluated regarding any newly developed pain in the joint of the throwing shoulder, and categorized into either the non-pain group or the pain group. RESULTS: Although all muscle SEMs tended to increase in both the throwing and non-throwing shoulders, no significant difference was observed in the prevalence of shoulder joint pain between ages (p = 0.541). The results of a binominal logistic regression analysis, adjusted for age, body mass index, playing position in baseball, frequency of baseball practice, shoulder range of motion, and muscle strength showed that a decrease in SEM values of the supraspinatus was a risk factor for the development of new pain (odds ratio: 0.056; 95% confidence interval 0.011-0.299; p = 0.001). CONCLUSIONS: The elasticity of muscle tissues around the throwing shoulder increased with age, and low tissue elasticity of the supraspinatus of the throwing shoulder was a factor that triggered pain during throwing motions.

Change in the pennation angle of the supraspinatus muscle after rotator cuff tear repair.

BACKGROUND: The pennation angle is an important architectural and functional feature of pennate muscles. The purpose of this study was to investigate the change in the pennation angle of the supraspinatus muscle after rotator cuff tear repair. MATERIALS AND METHODS: The study included 68 patients who underwent arthroscopic rotator cuff repair and magnetic resonance imaging. The size of the tear was measured under arthroscopic visualization. The pennation angle of the supraspinatus both preoperatively and postoperatively and the integrity of the repaired cuff were determined by magnetic resonance imaging. RESULTS: The preoperative pennation angle was significantly greater with enlargement of the tear size (P < .0001, analysis of variance). The retear rate was 29% in patients with medium tears and 59% in patients with large or massive tears. No retear was noted in patients with partial and small tears. The retear rate was 90.9% when the preoperative pennation angle was 20° or greater and was 12.3% when this angle was 19° or less, and the risk ratio for retear was 7.4 when this angle was 20° or greater. For repair-type tears, comparison between the preoperative and postoperative pennation angles showed a significant decrease in the mean value from 11.8° ± 3.7° to 9.9° ± 3.0° in the medium tear group (P = .007, paired t test) but no significant difference in the large or massive tear group (from 15.1° ± 7.0° to 13.3° ± 5.8°) (P = .33). For retear-type tears, no significance was found between groups. CONCLUSION: The preoperative pennation angle is directly correlated with the tear configuration and could be one of the prognostic factors for postoperative cuff integrity. To restore the pennation angle, primary repair is more appropriate in smaller rotator cuff tears than in medium-sized tears.

Effect of a cathepsin K inhibitor on arthritis and bone mineral density in ovariectomized rats with collagen-induced arthritis.

OBJECTIVES: Cathepsin K is expressed by osteoclasts and synovial fibroblasts and degrades key components of bone and cartilage. Inhibition of cathepsin K protease activity may be beneficial for the prevention of bone erosion and cartilage degradation in rheumatoid arthritis (RA). The collagen-induced arthritis (CIA) rat model is well established for studying the pathology and treatment of RA. We investigated the effect of ONO-KK1-300-01, a cathepsin K inhibitor (CKI), on arthritis and bone mineral density (BMD) in rats with CIA. METHODS: Seven-month-old female Sprague Dawley rats were divided into 5 groups: rats without CIA (CNT); CIA rats that underwent ovariectomy (OVX) and were treated with CKI; CIA rats that underwent OVX and were treated with vehicle (Veh); CIA rats that underwent sham surgery and were treated with CKI; and CIA rats that underwent sham surgery and were treated with Veh. CKI was orally administered at a dose of 15 mg/kg, thus initiating collagen sensitization, until death at 4 weeks. We evaluated hind paw thickness and the arthritis score every week until death. Radiographs of the resected left foot were obtained with a soft X-ray apparatus. Destruction of bone and cartilage was classified and scored as previously described by Engelhardt et al. BMD was measured by bone densitometry at the halfway point between the distal metaphysis and the diaphysis of the resected right femur. We also performed histomorphometry of the proximal left tibia, histological evaluation of arthritis, and a bone strength test. RESULTS: CKI administration significantly reduced hind paw thickness and the arthritis score, and prevented a decrease in BMD. The radiographic score was significantly lower in the CKI group than in the Veh group. In the histomorphometric analysis, bone-resorption parameters were significantly lower in the CKI groups than in the Veh groups. CKI significantly inhibited synovial proliferation in the CIA rats. In the bone strength test, the ultimate stress was significantly higher in the CKI groups than in the Veh groups. CONCLUSION: Our findings indicate that cathepsin K inhibitors may inhibit systemic and local bone loss, ameliorate arthritis, and attenuate the decrease of bone strength in an animal model of arthritis.

Conservative treatment for lumbar compartment syndrome shows efficacy over 2-year follow-up: a case report and literature review.

BACKGROUND: Since in all studies of conservative treatment of lumbar compartment syndrome the follow-up duration was less than 6 months, it is difficult to draw firm conclusions. PURPOSE: To report a patient with lumbar paraspinal compartment syndrome who was treated conservatively over a follow-up period of 2 years. STUDY DESIGN: This is a case report of a 23-year-old male college student with lumbar paraspinal compartment syndrome who was treated conservatively. METHODS: We report a case of a 23-year-old male college student with lumbar paraspinal compartment syndrome who was treated conservatively. We repeatedly checked his physical examination, laboratory tests, lumbar compartment pressures, and magnetic resonance imaging, and surgical teams were readily prepared to operate should the patient's condition worsen. To prevent complications of rhabdomyolysis, hydration and alkalization were performed. We followed him up to 2 years after discharge. RESULT: Although the temporal changes on MRI up to the 1-year point, the patient continued to have no symptoms. CONCLUSIONS: Conservative therapy can be recommended if rhabdomyolysis is under control.

Effect of raloxifene on arthritis and bone mineral density in rats with collagen-induced arthritis.

We studied the effect of raloxifene (RAL) on arthritis and bone mineral density (BMD) in rats with collagen-induced arthritis (CIA). Seven-month-old female Sprague-Dawley rats were divided into five groups: rats without CIA (CNT), CIA rats that underwent ovariectomy (OVX) and were treated with RAL (CIA + OVX + RAL), CIA rats that underwent OVX and were treated with vehicle (CIA + OVX + Veh), CIA rats that had sham surgery and were treated with RAL (CIA + sham + RAL), and CIA rats that had sham surgery and were treated with vehicle (CIA + sham + Veh). RAL was orally administered at 10 mg/kg every day for 3 weeks, beginning 1 week after initial sensitization until death at 4 weeks. Every week until death, we evaluated hind paw thickness and arthritis score. BMD was measured by peripheral quantitative computed tomography at the distal metaphysis and the diaphysis of the femur; we also performed histomorphometry of the proximal tibia and histological evaluation of arthritis. RAL administration suppressed hind paw thickness and arthritis score and prevented decreases in BMD and cortical thickness. In the histomorphometric analysis, bone-resorption parameters were significantly lower in the RAL groups than in the Veh groups. RAL significantly inhibited synovial proliferation in CIA rats. RAL effects on arthritis and bone were apparent regardless of whether an animal had undergone OVX. RAL could suppress arthritis and bone loss in estrogen-replete or -depleted rats. These findings, using an animal model, indicate the potential usefulness of RAL as an effective treatment for premenopausal RA patients as well as postmenopausal ones.

Spinal subdural haematoma concurrent with cranial subdural haematoma: Report of two cases and review of literature.

Subdural haematomas co-existing in the cranium and spine are considered extremely rare. We report 2 cases demonstrating the condition described here with a review of literature. One of these 2 patients was the first case in which the spinal lesion was found before the cranial lesion. A 66-year-old man without trauma presented with paraparesis accompanied by severe leg pain. The patient was diagnosed as having spinal subdural haematoma extending from L1 to S1 vertebral levels with magnetic resonance images (MRI). Two days after admission, the patient developed disorientation and abnormal behavior; therefore, computed tomography (CT) of brain was performed, and chronic cranial subdural haematoma was observed. A 60-year-old man who developed headache showing gradually progressive was diagnosed as having cranial subdural haematoma on CT. Three days after admission, he became insomnolent due to severe low back pain radiating to ankle. On MRI, subdural haematoma was found extending from L3/4 to S2 vertebral levels. Only brain surgery was performed for all cases by the neurosurgeons. Paraparesis and severe leg pain, which were derived from spinal lesions, showed recovery approximately 2 weeks after onset and spinal subdural haematoma was completely resolved on MRI obtained 2 or 5 months after onset, respectively. There is a possibility that the incidence of spinal subdural haematoma concurrent with cranial subdural haematoma could be underestimated because the doctor had not obtained CT or MRI of the brain. Doctors should aware of such a condition and check patients with spinal subdural haematoma for neurological signs derived from brain lesions. Spontaneous resolution of spinal subdural haematoma was observed; therefore, surgery for this condition should be indicated only for patients with moderate or severe paraparesis or paraparesis deteriorated.

Plantar pressure distribution during gait in athletes with functional instability of the ankle joint: preliminary report.

This study addressed the hypothesis that gait characteristics differ between normal subjects and athletes suffering from functional instability (FI) of the ankle joint. FI of the ankle joint is one of the most common residual disabilities after an acute ankle sprain. However, the influences of the FI of the ankle joint on the gait characteristics are not well understood. Athletes suffering from FI of the ankle joint and healthy control subjects were examined. Pressure, area, and force during gait were measured using a pressure measuring system. These in vivo plantar pressure measurements were performed during free walking. The foot angle and the pronation-supination index were calculated. Those in the FI group were found to exhibit a significantly lower dynamic foot angle and a greater pronation-supination index at the midsupport phase of gait than those in the control group. The results showed increased adduction-supination of the foot at the stance phase of gait in those with FI of the ankle joint.