Evaluation of the reproducibility of preoperative three-dimensional computed tomography planning for posterolateral approach total hip arthroplasty

The anteversion of the stem is occasionally intentionally changed by the surgeon for patients with smaller femoral neck anteversion during total hip arthroplasty (THA). However, the reproducibility of preoperative planning with increasing anteversion has been rarely assessed. The present study investigated it using two types of stems. This retrospective study included patients who underwent primary posterolateral THA using taper-wedge (TS group; 73 hips) and anatomical (AS group; 70 hips) stems. Characteristics of sex and age were matched in the two groups by propensity score matching. In both groups, the relationship between the preoperative three-dimensional planning and postoperative stem position, and the relationship between postoperative stem position and femoral neck anteversion (FNA) were evaluated. In the TS group, there were no significant differences in average stem anteversion (SA) between preoperative planning and postoperative placement (36.1° ± 7.0° and 36.6° ± 11.1°, respectively: p = 0.651). The absolute error of SA was 8.1° ± 6.4°. In the AS group, the postoperative SA was significantly smaller than the preoperative planning SA (22.7° ± 11.6° and 30.0° ± 9.3°, respectively: p < 0.001). The absolute error of SA was 9.0° ± 5.8°. The postoperative SA was significantly larger than the FNA in the TS group (36.6° ± 11.1° and 26.3° ± 10.9°, respectively: p < 0.001). However, no significant differences between the two were observed in the AS group (23.7° ± 10.1° and 22.7° ± 11.6°, respectively: p = 0.253). The preoperative planning of intentional increasing anteversion did not show high reproducibility with taper-wedge and anatomical stems. The anatomical stem was placed according to the femoral medullary canal regardless of preoperative planning with increased SA.

Fracture risk assessment of vascularized medial femoral condylar bone graft: A finite element analysis

BACKGROUND

Vascularized medial femoral condyle (MFC) bone graft is useful for pseudarthrosis and osteonecrosis, but has the risk of fracture as a complication. This study aimed to create multiple three-dimensional (3D) finite element (FE) femur models to biomechanically evaluate the fracture risk in the donor site of a vascularized MFC bone graft.

METHODS

Computer tomography scans of the femurs of nine patients (four males and five females) with no left femur disease were enrolled in the study. A 3D FE model of the left femur was generated based on the CT images taken from the patients. The descending genicular artery (DGA), the main nutrient vessel in vascularized MFC bone grafts, divides into the proximal transversal branch (TB) and the distal longitudinal branch (LB) before entering the periosteum. Thirty-six different bone defect models with different sizes and locations of the harvested bone were created.

RESULTS

The highest stress was observed in the proximal medial and metaphyseal portions under axial and external rotation, respectively. In the bone defect model, the stress was most elevated in the extracted region's anterior or posterior superior part. Stress increased depending on proximal location and harvested bone size.

CONCLUSION

Increasing the size of the bone graft proximally raises the stress at the site of bone extraction. For bone grafting to non-load-bearing areas, bone grafting distally using LB can reduce fracture risk. If TB necessitates a larger proximal bone extraction, it is advisable to avoid postoperative rotational loads.

Time elapsed from definitive diagnosis to surgery for osteonecrosis of the femoral head: a nationwide observational study in Japan

OBJECTIVES

This study documents the time elapsed from the diagnosis of osteonecrosis of the femoral head (ONFH) to surgery, exploring the factors that influence ONFH severity.

DESIGN

Retrospective observational study of a nationwide database.

SETTING

The Kaplan-Meier method with log-rank tests was applied to examine the period from definitive diagnosis of ONFH to surgery using any surgery as the end point. For bilateral cases, the date of the first surgery was the endpoint.

PARTICIPANTS

This study included 2074 ONFH cases registered in 34 university hospitals and highly specialised hospitals of the multicentre sentinel monitoring system of the Japanese Investigation Committee between 1997 and 2018.

MAIN OUTCOME MEASURE

The primary outcome was the time from diagnosis to surgery. The secondary outcome was the proportion of subjects remaining without surgery at 3, 6 and 9 months, and at 1, 2 and 5 years after diagnosis.

RESULTS

The median time to surgery was 9 months (IQR 4-22 months) after diagnosis of ONFH. The time to surgery was significantly shorter in the alcohol alone group and the combined corticosteroid and alcohol group than in the corticosteroid alone group (p=0.018 and p<0.001, respectively), in early stage ONFH with no or mild joint destruction (stages II and III, p<0.001), and with joint preserving surgery (p<0.001). The proportion without surgery was 75.8% at 3 months, 59.6% at 6 months, 48.2% at 9 months, 40.5% at 1 year, 22.2% at 2 years and 8.3% at 5 years.

CONCLUSION

ONFH has been considered to be an intractable disease that often requires surgical treatment, but the fact that surgery was performed in more than half of the patients within 9 months from diagnosis suggests severe disease with a significant clinical impact.

TRIAL REGISTRATION NUMBER

Chiba University ID1049.

Assessing the utility of osteoporosis self-assessment tool for Asians in patients undergoing hip surgery

Objectives

Diagnosis and treatment of osteoporosis are instrumental in obtaining good outcomes of hip surgery. Measuring bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA) is the gold standard for diagnosing osteoporosis. However, due to limited access to DXA, there is a need for a screening tool to identify patients at a higher risk of osteoporosis. We analyzed the potential utility of the Osteoporosis Self-assessment Tool for Asians (OSTA) as a screening tool for osteoporosis.

Methods

A total of 1378 female patients who underwent hip surgery at 8 institutions were analyzed. For each patient, the BMD of the proximal femoral region was measured by DXA (DXA-BMD), and the correlation with OSTA score (as a continuous variable) was assessed. Receiver operating characteristic (ROC) curve analysis was performed to assess the ability of OSTA score to predict osteoporosis. Lastly, the OSTA score was truncated to yield an integer (OSTA index) to clarify the percentage of patients with osteoporosis for each index.

Results

DXA-BMD showed a strong correlation with OSTA (r = 0.683; P < 0.001). On ROC curve analysis, the optimal OSTA score cut-off value of -5.4 was associated with 73.8% sensitivity and 80.9% specificity for diagnosis of osteoporosis (area under the curve: 0.842). A decrease in the OSTA index by 1 unit was associated with a 7.3% increase in the probability of osteoporosis.

Conclusions

OSTA is a potentially useful tool for screening osteoporosis in patients undergoing hip surgery. Our findings may help identify high-risk patients who require further investigation using DXA.

Change in hip laxity after anterior capsular suture in total hip arthroplasty using direct anterior approach

It is clinically unclear whether anterior capsular suture improves hip laxity in total hip arthroplasty using direct anterior approach (DAA-THA). This study aimed to clarify the impact of anterior capsular suture for hip laxity in DAA-THA. In this study, 121 hips of 112 patients who underwent DAA-THA were prospectively enrolled. Mean age was 64.7 ± 10.1 years, and the subjects consisted of 35 hips in 32 men and 86 hips in 80 women. To evaluate hip laxity after implantation, axial head transfer distance (HTD) when the hip was pulled axially at 15 kg was compared before and after anterior capsular suture at the hip intermediate and 10° extension positions. HTD in the intermediate and 10° extension positions averaged 5.9 ± 4.6 mm and 6.3 ± 4.6 mm before the suture, and 2.6 ± 2.7 mm and 2.9 ± 3.1 mm after the suture, respectively. HTD after the suture significantly decreased in both hip positions (p < 0.0001). The amount of change by the suture was greater in cases with greater pre-suturing HTD. In DAA-THA, the anterior capsular suture significantly improved hip laxity against axial traction force, it may contribute to improvement of postoperative hip stability, especially in cases with greater laxity before the suture.

Autologous Chondrocyte Implantation With Collagen Membrane Using a Knotless Suture Bridge Technique

Autologous chondrocyte implantation (ACI) has been covered by insurance in Japan since April 2013, expanding the range of treatments for extensive knee cartilage damage. Initially, the periosteum was used for the fixation of cultured cartilage, but since February 2019, the introduction of collagen membranes has shortened surgery time and simplified the procedure. We report a case where we used the knotless suture bridge technique for a more straightforward and secure fixation with a collagen membrane. The patient was a 61-year-old male who experienced right knee pain a year earlier when stepping downstairs. Conservative treatment at a local hospital was ineffective, and he was referred to our department. At the initial examination, the right knee had an extension of -5° and a flexion of 130°. A simple X-ray of the right knee showed osteosclerosis with a translucent bone image at the medial femoral condyle. Weight-bearing full-length X-ray of the lower limb showed a femorotibial angle (FTA) of 186°, a hip-knee-ankle (HKA) angle of 12.5° varus, a percentage of mechanical axis (%MA) of 15%, and a medial proximal tibial angle (MPTA) of 78°, indicating a significant varus deformity. CT and MRI revealed a cartilage defect of 36 mm in length and 16 mm in width and a bone defect with a maximum depth of 15 mm at the medial femoral condyle. The patient underwent surgery for a traumatic cartilage defect of the medial femoral condyle. For the bone defect, autologous bone grafting was performed, and for the cartilage defect, ACI was done. The ACI involved fixation with a collagen membrane using 1.3 mm suture tape and BC PushLock anchor (Arthrex, Naples, Florida, United States) in a knotless suture bridge technique. Additionally, hybrid closed-wedge high tibial osteotomy (HCWHTO) was performed for alignment correction. At eight months post surgery, MRI proton density sagittal images confirmed the joint surface by the cartilage layer, and the Modified Outerbridge Cartilage Repair Assessment (MOCART) score was 80. At 12 months post surgery, the Japanese version of the Knee Injury and Osteoarthritis Outcome Score (J-KOOS) improved from 46.43 to 82.14 for symptoms, 58.33 to 83.33 for pain, 95.59 to 100 for activities of daily living (ADL), 45 to 75 for sports, and 68.75 to 87.50 for quality of life (QOL). X-rays showed an FTA of 173°, an HKA of 0°, and a %MA of 58%, indicating a favorable course. The knotless suture bridge technique for collagen membrane fixation during ACI is considered a convenient and time-saving method.

Lipid index to quantify the absorbed lipids in retrieved UHMWPE components of joint arthroplasty

BACKGROUND

The ultra-high molecular weight polyethylene (UHMWPE) component of artificial joints is one of the most important factors affecting the clinical outcomes of joint arthroplasty. Although the possibility of in vivo UHMWPE degradation caused by absorbed lipids has been reported, a quantitative evaluation of this phenomenon has not yet been performed.

OBJECTIVE

This study aimed to establish the lipid index (LI) as a quantitative indicator of the amount of absorbed lipids and the first step to quantify their effects on UHMWPE.

METHODS

The LI was defined using the infrared spectrum obtained with a Fourier-transform infrared spectrophotometer and verified using the retrieved UHMWPE components.

RESULTS

The LI was consistent with the amount of extract recovered in reflux extraction with hexane. In addition, the LI could replace lipid extraction for calculating the oxidation index (OI) because the value obtained by subtracting the LI from the OI showed good agreement with the OI obtained after lipid extraction.

CONCLUSION

The LI represents the amount of lipids absorbed by UHMWPE and is useful for quantitatively evaluating the effects of lipids on UHMWPE. In addition, the LI enables OI measurements that are unaffected by absorbed lipids without requiring troublesome lipid-extraction procedures.

Development and validation of an open-source tool for opportunistic screening of osteoporosis from hip CT images

Aims

This study aimed to develop and validate a fully automated system that quantifies proximal femoral bone mineral density (BMD) from CT images.

Methods

The study analyzed 978 pairs of hip CT and dual-energy X-ray absorptiometry (DXA) measurements of the proximal femur (DXA-BMD) collected from three institutions. From the CT images, the femur and a calibration phantom were automatically segmented using previously trained deep-learning models. The Hounsfield units of each voxel were converted into density (mg/cm3). Then, a deep-learning model trained by manual landmark selection of 315 cases was developed to select the landmarks at the proximal femur to rotate the CT volume to the neutral position. Finally, the CT volume of the femur was projected onto the coronal plane, and the areal BMD of the proximal femur (CT-aBMD) was quantified. CT-aBMD correlated to DXA-BMD, and a receiver operating characteristic (ROC) analysis quantified the accuracy in diagnosing osteoporosis.

Results

CT-aBMD was successfully measured in 976/978 hips (99.8%). A significant correlation was found between CT-aBMD and DXA-BMD (r = 0.941; p < 0.001). In the ROC analysis, the area under the curve to diagnose osteoporosis was 0.976. The diagnostic sensitivity and specificity were 88.9% and 96%, respectively, with the cutoff set at 0.625 g/cm2.

Conclusion

Accurate DXA-BMD measurements and diagnosis of osteoporosis were performed from CT images using the system developed herein. As the models are open-source, clinicians can use the proposed system to screen osteoporosis and determine the surgical strategy for hip surgery.

Negative correlation between central sensitization and forgotten joint score-12 after total hip arthroplasty

BACKGROUND

Central sensitization is a condition in which even mild stimuli cause pain due to increased neuronal reactivity in the dorsal horn of the spinal cord. It is one of factors of chronic pain in patients with osteoarthritis. However, it is unknown whether central sensitization relates to clinical outcomes after total hip arthroplasty (THA). This study aimed to clarify whether preoperative central sensitization relates to the forgotten joint score-12 (FJS) after THA. Moreover, the secondary outcome was to identify which items in the FJS were most related by central sensitization.

METHODS

This retrospective analysis included 263 hips (263 patients; 51 males and 212 females) that underwent primary THA in our institute and were available for evaluation one year postoperatively. The average patient age was 64.8 ± 11.9 years. The Central Sensitization Inventory (CSI) part A, which is a patient-reported outcome, was used to measure preoperative central sensitization. The correlation between preoperative CSI and postoperative FJS and the association between postoperative FJS and preoperative CSI severity were determined. Moreover, difference in each FJS item was evaluated by CSI severity.

RESULTS

Twenty-six patients (9.9%) had central sensitization preoperatively. Preoperative CSI scores and postoperative FJS were negatively correlated (r =  - 0.331, p < 0.0001). The postoperative FJS was significantly lower in patients with moderate or higher preoperative CSI severity than that in patients with subclinical or mild preoperative CSI severity (p < 0.05). FJS items with movement of daily life were significantly worse in the moderate or higher CSI severity compared with subclinical group (p < 0.05 or p < 0.01).

CONCLUSION

Central sensitization prior to THA negatively related to postoperative FJS. In particular, the relationship of central sensitization was found to be significant in FJS items with movement, which would lead to lower patient satisfaction after THA. To get better postoperative outcomes in patients with preoperative central sensitization, improving central sensitization would be important.

Efficacy of repeated administration of intravenous acetaminophen for pain management after total knee arthroplasty

Intravenous acetaminophen is an integral component of multimodal postoperative pain management. This prospective study aims to assess the efficacy of the repeated administration of intravenous acetaminophen and the impact on postoperative patient satisfaction with postoperative pain management after total knee arthroplasty (TKA). We enrolled 98 patients scheduled for unilateral TKA. Patients were randomly assigned to receive either 1000 mg of intravenous acetaminophen at 6-hour intervals (AAP group) or not to receive intravenous acetaminophen (control group). All patients underwent single-shot femoral nerve block after general anesthesia, as well as intraoperative periarticular infiltration of analgesia prior to implantation. The primary outcome was the postoperative numerical rating scale (NRS) pain score at rest. The NRS score was measured just before the administration of study drugs, immediately after arrival in the ward (time 0), and at 6, 12, 18, 24, and 48 h (time 1 to time 5, respectively) postoperatively. We also evaluated the mean doses of rescue opioid use for 24 h postoperatively. At time 5, the AAP group had significantly improved mean NRS score than controls (3.0 vs. 4.0; P < 0.01). Rescue opioid use was significantly lower in the AAP group for 24 hours compared to controls (0.3 μg vs. 0.9 μg; P < 0.01). Repeated intravenous acetaminophen administration after TKA may provide better analgesia and reduce opioid use.

Medial Soft Tissue-Preserving Technique Impact on Sagittal Stability in Bi-cruciate Stabilized Total Knee Arthroplasty

Background

Sagittal stability in total knee arthroplasty is achieved through complex processes enabled by prosthetic design and intraoperative soft tissue balancing. This study investigated the effects of preserving medial soft tissue on sagittal stability in bicruciate stabilized total knee arthroplasty (BCS TKA).

Method

This retrospective study included 110 patients who underwent primary BCS TKA. The patients were divided into two groups: 44 TKAs were performed releasing medial soft tissue (CON group), and 66 TKAs were performed preserving medial soft tissue (MP group). We assessed joint laxity using tensor device and anteroposterior translation immediately after surgery using the arthrometer at 30° knee flexion. Propensity score matching (PSM) was performed according to preoperative demographic and intraoperative medial joint laxity, and further comparisons between the two groups were performed.

Result

After PSM analysis, medial joint laxity in the mid-flexion range tended to be smaller in the MP group than in the CONT group, with a significant difference at 60 degrees (CON group: - 0.2 ± 0.9 mm, MP group: 0.8 ± 1.3 mm, P < 0.05). Anteroposterior translation was significantly different between the two cohorts (CON group: 11.6 ± 2.5 mm, MP group: 8.0 ± 3.1 mm, P < 0.001).

Conclusion

This study demonstrated the effects of preserving medial soft tissue on postoperative sagittal stability in BCS TKA. We concluded that this surgical procedure enhances postoperative sagittal stability in the mid-flexion range in BCS TKA.

Comparing inter- and intraobserver reliability between two-dimensional and three-dimensional measurements in the tibial component position of unicompartmental knee arthroplasty

In unicompartmental knee arthroplasty (UKA), the tibial component has a small coronal plane width, the tibia and tibial component rotations are mismatched, and the large tibial component posterior tilt may make accurate measurements of component positions difficult in radiography. The study aimed to assess the intra- and interobserver reliabilities of radiographic (2D) and 3D computed tomography (3D-CT) measurements and to determine the minimum detectable change (95% confidence level, MDC95) in the tibial component position measurements in UKA. The study included 23 females and 7 males. Two surgeons measured the tibial component position. Intraclass and interclass correlation coefficients (ICC) were calculated to obtain reliability, and Bland-Altman analysis was performed to assess systematic errors. The MDC95 was calculated according to MDC95 = standard error of measurement × 1.96 × √2. In the 2D and 3D- CT measurements, intraobserver reliability for coronal and sagittal positions of the tibial component were sufficiently reliable, where ICCs were >0.8. In the coronal plane, the ICCs for interobserver reliability were lower in 2D (ICC, 0.5-0.7) than in 3D-CT (ICC > 0.9). Bland-Altman plots showed systematic bias in sagittal alignment in the 2D assessment. In the 3D assessment of intra- and interobserver reliability, the MDC95 of the coronal, sagittal, and axial planes was <2°. In the 2D intra- and interobserver reliability, the MDC95 of the coronal and sagittal planes was >2°. The 2D measurement had a risk of misidentifying the tibial component position in UKA.

Forgotten joint score is worse when the affected leg perceived longer than shorter after total hip arthroplasty

BACKGROUND

One of the causes of patient dissatisfaction after total hip arthroplasty (THA) is leg length discrepancy (LLD). Even when radiographic LLD (R-LLD) is within 5 mm, some people perceive the affected side to be longer, while others perceive it is shorter. The purpose of this study was to investigate the relationship between perceived LLD (P-LLD), R-LLD, and Forgotten Joint Score (FJS-12) after THA.

METHODS

A retrospective study of 164 patients with unilateral hip disease was conducted. Based on P-LLD after THA, they were classified into three categories: perceived short (PS 21 patients), no LLD (PN 121 patients), and perceived long (PL 22 patients). On the other hand, based on R-LLD after THA, they were divided into <  - 5 mm (RS 36 patients), - 5 mm ≤ x < 5 mm (RN 99 patients), and 5 mm ≥ (RL 29 patients), respectively. The proportion of P-LLD in the RN group was also evaluated. In each group, the relationship between P-LLD, R-LLD and FJS-12 was investigated.

RESULTS

After THA, the PL group had significantly worse FJS-12 (PS: 68.3 ± 26.2, PN: 75.0 ± 20.9, PL: 47.3 ± 25.2, P < .0001). In the R-LLD evaluation, there was no difference in FJS-12 among the three groups (RS: 73.7 ± 21.1, RN: 70.0 ± 24.5, RL: 67.7 ± 25.4, P < .53). The RN group perceived leg length to be longer (RN-PL) in 12.1% of cases, and the RN-PL groups had significantly worse FJS-12 (RN-PS: 65.4 ± 24.8, RN-PN: 73.8 ± 23.1, RN-PL: 41.8 ± 27.6, P < .0001).

CONCLUSION

One year after THA, patients with longer P-LLD had worse FJS-12, even if the R-LLD was less than 5 mm.

Comparison of simultaneous versus staged bilateral total hip arthroplasty via the direct anterior approach: A propensity score matched analysis

PURPOSE

It remains unclear whether simultaneous bilateral total hip arthroplasty (SimBTHA) or staged bilateral total hip arthroplasty (StaBTHA) is clinically superior. No study has compared these two procedures matching surgical approach and patient background. This study aimed to clarify the differences between SimBTHA using direct anterior approach (SimBTHA-DAA) and StaBTHA using the direct anterior approach (StaBTHA-DAA).

METHODS

Patients who underwent THA between 2012 and 2020 were enrolled, resulting in a total of 1658 hips of 1388 patients. After propensity score matching for patient background, 204 hips of 102 patients (51 patients in each group) were examined. Clinical and radiographic outcomes, complications, intraoperative blood loss and blood transfusions (BT) were evaluated. In complications, we evaluated periprosthetic fractures, pulmonary embolism, deep venous thrombosis, surgical site infection and dislocation.

RESULTS

At the final follow-up, clinical and radiographic outcomes and complications were not significantly different between the groups. Intraoperative blood loss was equivalent for SimBTHA and the sum in the first- and second-stage StaBTHA. The total-BT rate was significantly higher for SimBTHA-DAA than for StaBTHA-DAA (p < .0001). The allogeneic BT rate was significantly higher in SimBTHA-DAA in the supine position (32.3%) than in StaBTHA-DAA (8.3%) (p = .007). However, no patient who received autologous BT required allogeneic BT.

CONCLUSIONS

Clinical and radiographic outcomes were equivalent between SimBTHA-DAA and StaBTHA-DAA. The allogeneic BT rate was significantly higher in SimBTHA-DAA than in StaBTHA-DAA. Autologous BT reduced the use of allogeneic BT in SimBTHA-DAA. Auto-BT may be useful for avoiding allo-BT in SimBTHA.

Accuracy of cup placement using computed tomography-based navigation system in total hip arthroplasty through the direct anterior approach

BACKGROUND

This study aimed to elucidate the accuracy of cup placement with the computed tomography (CT)-based navigation system (CTN) in the direct anterior approach (DAA)-total hip arthroplasty (THA) in the supine position compared with the mechanical cup alignment guide (MG) or the fluoroscopy (FS).

METHODS

A total of 171 hips of 156 patients undergone primary THA were classified into the following three groups (the MG group: 63 hips, the FS group: 58 hips, the CTN group: 50 hips). Comparing the preoperative planning with postoperative CT measurement by three-dimensional templating software, the accuracy of cup placement was investigated in the three groups.

RESULTS

There were significant differences in the mean absolute error of radiographic inclination (RI) between the MG group (4.4° ± 3.2°) and the CTN group (2.8° ± 2.5°) (p = 0.01). The mean absolute error of radiographic anteversion (RA) also showed significant differences between the CTN group (2.8° ± 1.9°) and the MG group (5.8° ± 4.7°) (p = 0.0001) or the FS group (4.8° ± 4.1°) (p = 0.02). Regarding the cup center position, the mean absolute error of vertical position from preoperative planning was the smallest in the CTN group (1.8 ± 1.4 mm) compared with those in other groups (MG: 3.3 ± 3.2 mm, p = 0.007, FS: 3.2 ± 3.0 mm, p = 0.017).

CONCLUSION

The CTN guarantees accurate cup placement in the DAA-THA in the supine position compared with the MG and FS groups.

Novel nano-hydroxyapatite coating of additively manufactured three-dimensional porous implants improves bone ingrowth and initial fixation

Electron beam melting (EBM) has been used to fabricate three-dimensional (3D) porous Ti-6Al-4V surfaces for acetabular cups in total hip arthroplasty. However, there are radiographic concerns regarding poor implant fixation and bone ingrowth around electron beam melted (EBMed) 3D porous cups. We hypothesize that nano-hydroxyapatite (nHA) coating can promote bone ingrowth and thus decrease the occurrence of radiolucent lines around EBMed 3D porous cups. This study aimed to investigate the effect of a novel nHA coating on the biological performance of EBMed 3D porous implants in a beagle transcortical model. Low-porosity (control) and high-porosity 3D porous Ti-6Al-4V implants were manufactured using EBM. Half of the high-porosity implants were coated with nHA without clogging the 3D pores. Implants were inserted into the femoral diaphysis of the beagles. The beagles were euthanized at 4, 8, and 12 weeks postoperatively, and push-out testing was performed. Bone ingrowth was evaluated by histological analysis. Although the increase in porosity alone had no effect on biological behavior, the addition of nHA to high-porosity 3D implants significantly improved early bone fixation and bone ingrowth into the deep region of porous structures compared to low-porosity implants. This is the first report of a novel nHA coating that improved bone ingrowth into the deeper regions of 3D porous implants, which can prevent the occurrence of radiolucent lines around EBMed 3D porous cups.

Intraoperative determination of the risky angles and safe distances for preventing deep femoral artery injury during proximal femoral nailing for hip fractures in Asian people

OBJECTIVE

During proximal femoral nailing, deep femoral artery injury, a rare condition, is often missed and found late, leading to intractable complications such as false aneurysm, hematoma, and anemia. We aimed to determine the novel indicators of the high-risk vertical range and axial angle for deep femoral artery injury that can be easily confirmed intraoperatively using fluoroscopy for hip fracture.

METHODS

In a single hospital, the lower extremity computed tomography angiographies of 88 patients (50 men and 38 women) were analyzed. A reference plane was defined as the femoral neck and shaft on the same straight line in the lateral view. Reference points were the lower end of the lesser trochanter and distal femur at 140 mm from the tip of the greater trochanter. To determine the high-risk angle for deep femoral artery injury based on the reference plane, the angle from the reference plane to the deep femoral artery (bone-arterial angle) and the shortest distance between the surfaces of the femur and the deep femoral artery (bone-artery distance) were measured at the lesser trochanter and the greater trochanter. We analyzed the bone-arterial angle and bone-artery distance values, their differences among the sexes, and their correlation with body height and body weight.

RESULTS

Overall, in the lesser trochanter, the mean bone-arterial angle and bone-artery distance were 19.2° ± 8.0° and 22.9 ± 4.7 mm, respectively. In the greater trochanter, the mean bone-arterial angle and bone-artery distance were -33.9° ± 17.0° and 11.3 ± 4.1 mm, respectively. The mean bone-artery distance of the lesser trochanter was significantly longer in men than in women (24.1 ± 4.5 mm and 21.4 ± 4.5 mm, respectively, P < 0.01), and for the lesser trochanter, positive correlations were found between body height and both bone- arterial angle and bone-artery distance (r=0.373, P < 0.001; and r=0.456, P < 0.0001, respectively), with body weight and bone-artery distance positively correlated (r=0.367, P < 0.001). At the greater trochanter, there were negative correlations between body height and bone-arterial angle (r=-0.5671, P < 0.0001), body weight, and bone-arterial angle (r=-0.338, P < 0.01).

CONCLUSION

The knowledge of our reference plane and high-risk angles and distances allows surgeons to minimize the risk of deep femoral artery injury. These are easily confirmed intraoperatively using fluoroscopy, allowing surgeons to avoid maneuvering in the deep femoral artery range.

LEVEL OF EVIDENCE

Level IV, Diagnostic Study.

Ultrasonography-detected synovitis of hand is associated with the presence of synovitis in the forefoot of patients with rheumatoid arthritis

BACKGROUND

In rheumatoid arthritis, forefoot disease activity can lead to joint damage, pain, and disability during weight-bearing activities; therefore, the evaluation and control of forefoot disease activity is important. We aimed to investigate an association between the prevalence of abnormalities in the forefoot based on ultrasonography (US) and the clinical and US findings related to arthritis and identify factors related to the presence of synovitis in the forefoot of RA patients.

METHODS

In total, 810 metatarsophalangeal joints of 81 rheumatoid arthritis patients were examined using US. Patients were assigned to either a forefoot synovitis group (n = 22), with foot synovitis detected using US, or a non-forefoot synovitis group (n = 59). We assessed associations between clinical parameters and US finding of the hand and US finding of the metatarsophalangeal joints.

RESULTS

The following were significantly higher in forefoot synovitis group than in non-forefoot synovitis group: swollen joint count [P < 0.001]; Disease Activity Score 28 based on C-reactive protein [P < 0.05]; clinical disease activity index [P < 0.001]; and total Power Doppler score of the hand [P < 0.001]. Receiver-operating characteristic analysis for total Power Doppler scores of the hand to suggest the presence of synovitis in the metatarsophalangeal joints showed that a total Power Doppler score of the hand of ≥5 was associated with synovitis in the metatarsophalangeal joints, with a sensitivity of 68% and a specificity of 85% (odds ratio = 11.9).

CONCLUSION

Total Power Doppler scores of the hand had a good valuable score for suggesting the presence of synovitis in metatarsophalangeal joints of rheumatoid arthritis patients.

Low frequency of local findings in periprosthetic hip infection caused by low-virulent bacteria compared to periprosthetic knee infection

Periprosthetic joint infection (PJI) is suspected when local findings such as pain, swelling, hyperthermia, and sinus tract are present. However, the frequency of these findings and the difference between hip and knee are unclear. This study compared the positive rates of local findings in periprosthetic hip infection (PHI) with periprosthetic knee infection (PKI), and aimed to identify potential risk factors associated with the frequency. One hundred one PJI (46 hips and 55 knees) fulfilled the 2018 Musculoskeletal infection society criteria were analysed retrospectively to assess the positive rates of each local finding. Patients were categorized into two groups based on the presence or absence of each local finding, and the influence of two potential risk factors [body mass index (BMI) and C-reactive protein (CRP)] was investigated. Causative bacterial species were divided into high and low-virulent groups, and then culture negative cases were included in low-virulent group. PHI had significantly lower rates of pain, swelling and hyperthermia compared to PKI. Overall, up to one-third of PHI had pain as only symptom. High BMI and low-virulent bacteria were associated with lower frequency of swelling and hyperthermia in PHI. CRP had no impact on positive rates of local findings. PHI was oligosymptomatic in a significant percentage of cases. This is particularly important in obese patients and infection by low-virulent bacteria.

Low psoas major muscle area as a risk factor for contralateral hip fracture following intertrochanteric fracture

OBJECTIVE

This study aimed to investigate the relationship between the psoas major muscle area as a risk factor and subsequent contralateral hip fractures in patients with initial intertrochanteric fractures.

METHODS

Of 136 treated for intertrochanteric fractures, 104 female patients had computed tomography done to assess their fractures at initial stage and had been followed up for more than 2 years. These patients were then divided into 2 groups: i.e. those who had a contralateral hip fracture (CF) (n=16) and those who did not (NF) (n=88) groups. We mainly assessed the relationship between the corrected psoas major muscle area (CPMA) at initial fracture and the occurrence of contralateral hip fracture.

RESULTS

The CF group had significantly lower CPMA than the NF group (p=0.001). There was positive correlation between the CPMA and the period from the initial to the contralateral hip fracture in the CF group. The CPMA cutoff value of 480.98 mm2/m2, was showed sensitivity of 63.6% and specificity of 87.5% in receiver operating characteristic curve analysis for all patients.

CONCLUSIONS

The lower CPMA was associated with the contralateral hip fracture within 2 years from initial intertrochanteric fracture. The low CPMA would be a risk factor for contralateral hip fracture.

Comparison of bacterial culture results of preoperative synovial fluid and intraoperative specimens in patients with joint infection

OBJECTIVES

The details of relationship between bacterial culture results of preoperative and intraoperative specimens in same patients with native joint septic arthritis (NJSA) and periprosthetic joint infection (PJI) are unknown. This study aims to reveal the difference of culture results of preoperative synovial fluid and intraoperative specimens and evaluate the risk factors for detecting different species intraoperatively from preoperative synovial fluid.

METHODS

This study included 55 joints diagnosed with 16 NJSA and 39 PJI. Bacterial culture positive rates and identified bacterial species were compared between preoperative synovial fluid and intraoperative tissue/synovial fluid. We also examined the presence or absence of sinus tracts and antimicrobial agents as risk factors in patients with different bacterial species in intraoperative specimens from preoperative synovial fluid.

RESULTS

The culture positive rates were not significantly different between preoperative synovial fluid and intraoperative specimens. Different bacterium were detected in 10.9% joints by intraoperative tissue and 14.6% joints by intraoperative synovial fluid. The positive rate of sinus tract was significantly higher in patients with different bacterial species (62.5%) than without different bacterial species (12.8%, p < 0.01). Conversely, antimicrobial agent was not significantly difference.

CONCLUSION

This study demonstrated that different bacterium from preoperative culture results were detected in 10-15% joints by intraoperative specimens in NJSA and PJI. The sinus tract was a risk factor for identifying different bacterial species in the intraoperative specimens. Therefore, in cases of sinus tract, it is necessary to examine multiple specimens of both intraoperative tissue and synovial fluid for increasing the detection rate.

Synovial fluid presepsin as a novel biomarker for the rapid differential diagnosis of native joint septic arthritis from crystal arthritis

OBJECTIVE

To investigate whether presepsin can be used as a novel biomarker to differentiate between native joint septic arthritis (NJSA) and crystal arthritis (CA).

METHODS

This study included 75 patients diagnosed with either NJSA (n = 21) or CA (n = 54). Presepsin in synovial fluid and blood, C-reactive protein, and procalcitonin were measured and compared between the NJSA and CA groups. Receiver operating characteristic (ROC) curve analyses were performed to differentiate between the two groups.

RESULTS

Synovial fluid and blood presepsin were significantly higher in the NJSA group than in the CA group (p < 0.0001 and p < 0.01, respectively). The area under the ROC curve for synovial fluid presepsin in the NJSA group compared with the CA group was 0.93 (sensitivity 85.7%, specificity 85.2%, positive predictive value 69.2%, negative predictive value 93.9%, positive likelihood ratio 5.79, negative likelihood ratio 0.17). Among the tests, synovial fluid presepsin was the most accurate.

CONCLUSIONS

Measurement of synovial fluid presepsin is reliable for the early diagnosis of NJSA, and synovial fluid presepsin could be used as a novel biomarker for differentiating between NJSA and CA.

Investigation of the effect of intraoperative mediolateral stability on postoperative sagittal stability after bi-cruciate stabilized total knee arthroplasty

Purpose

This study investigated the effect of mediolateral stability on sagittal stability in bi-cruciate stabilized total knee arthroplasty.

Method

This study included 59 patients. We intraoperatively assessed the component gap with a joint distraction force of 60 N for each compartment. Immediately after surgery, sagittal stability was assessed using an arthrometer.

Result

The intraoperative medial joint laxity at 30° of flexion was significantly correlated with postoperative anteroposterior translation (r = 0.276, p < 0.05).

Conclusion

This study demonstrated the effect of intraoperative mediolateral stability effect on postoperative sagittal stability. Improving medial stability may enhance postoperative sagittal stability.

Risk Factors Associated With Short-term Clinical Results After Total Hip Arthroplasty for Patients With Rheumatoid Arthritis

Clinical outcomes of total hip arthroplasty for rheumatoid arthritis are reportedly worse than those of total hip arthroplasty for osteoarthritis of the hip. The authors examined pre- and postoperative factors associated with the modified Harris hip score (mHHS). Fifty-one joints of 48 rheumatoid arthritis patients who underwent total hip arthroplasty were studied retrospectively. The authors examined the correlation between preoperative rheumatoid arthritis disease activity (Disease Activity Score in 28 joints-C-reactive protein and C-reactive protein) and mHHS at 1 year after total hip arthroplasty. Furthermore, pre- and postoperative mHHS values were compared between patients with other affected joints and patients with no affected joints in the lower limbs. The mean mHHS improved to 73.5 points postoperatively from 36.4 points preoperatively. Preoperative Disease Activity Score in 28 joints-C-reactive protein and C-reactive protein values were negatively correlated with pre- and postoperative mHHS values. Preoperative mHHS was not significantly different between the affected and not affected groups; however, postoperative mHHS was significantly lower in the affected group than in the not affected group. Total hip arthroplasty showed good clinical results for rheumatoid arthritis at short-term follow-up. However, pre- and postoperative mHHS values were influenced by preoperative rheumatoid arthritis disease activity. Moreover, the presence of additional affected joints in the lower limbs preoperatively resulted in a lower postoperative mHHS. Unlike patients with osteoarthritis, patients with rheumatoid arthritis often have multiple affected joints, which may contribute to a lower mHHS. Comprehensive treatment, including surgery for the other affected joints in the lower limbs, may improve a patient's postoperative mHHS. [Orthopedics. 2018; 41(6):e772-e776.].

Weight bearing joints destruction in rheumatoid arthritis

In many cases of rheumatoid arthritis (RA) joints of the upper extremities are affected. However, involvement of weight bearing joints of the lower extremities is strongly associated with a decreased activities of daily living ability such as gait disorder. Once the progression of weight bearing joint destruction occurs, lower extremity function will decrease even if RA disease activity is improved by pharmacotherapy. In this article, we investigated joint destruction-suppressing effects of pharmacotherapy on the hip and knee joints, as well as risk factors for joint destruction. We also discuss surgical treatment strategies and clinical outcomes for progressive joint destruction.

Postpartum pyogenic sacroiliitis with methicillin-resistant Staphylococcus aureus in a healthy adult: A case report and review of the literature

OBJECTIVE

Back and buttock pain during pregnancy and the postpartum period generally improves spontaneously and rarely causes problems. However, such pain is infrequently induced by pyogenic sacroiliitis.

CASE REPORT

We herein present a 37-year-old female patient with no previous medical history who developed pyogenic sacroiliitis with severe right buttock pain 7 days after cesarean delivery. Arthrocentesis was performed, and a culture revealed the presence of methicillin-resistant Staphylococcus aureus (MRSA). After 6 weeks of treatment with intravenous antibiotics, her infection became quiescent. Eight cases of pyogenic sacroiliitis during the postpartum period and seven cases during pregnancy have been reported, but most of the causative pathogens were methicillin-sensitive Staphylococcus or Streptococcus species.

CONCLUSION

This report describes the first case of postpartum pyogenic sacroiliitis caused by MRSA. The frequency of infection with MRSA has recently increased, and community-acquired MRSA, which affects even healthy young people, has also become a problem. Antibiotics for empirical therapy after a diagnosis of pyogenic sacroiliitis, including anti-MRSA antibiotics, should be carefully selected.

Treatment for Staphylococcus aureus infection following open wedge high tibial osteotomy using antibiotic-impregnated calcium phosphate cement

This report describes a case of Staphylococcus aureus infection following open wedge high tibial osteotomy, which was successfully treated with by implant removal and replacement with antibiotic-impregnated calcium phosphate cement along with external fixation. The infection occurred 7 months after primary surgery and was treated by implant removal, debridement, external fixation, and application of vancomycin impregnated calcium phosphate cement to fill the defect. Subsequently, the infection resolved completely, and the osteotomy healed with no correction loss. Compared with conventional bone cement, calcium phosphate cement might be an optimal material for certain cases of infection after open wedge high tibial osteotomy because of its higher antibiotic retention, biocompatibility, osteoconductivity, and compatibility with heatlabile antibiotics.

LEVEL OF EVIDENCE

V.

[Efficacy and adverse reactions of the TNFalpha inhibitor infliximab in rheumatoid arthritis]

Abundant evidence of infliximab (tumor necrosis factor inhibitor) has been collected in rheumatoid arthritis. Infliximab is effective not only for resolving the clinical symptoms, but also for preventing joint destruction. It has also been reported that discontinuation of this drug is possible after attaining low disease activity. This is one of the characteristics of infliximab. However, patients should be adequately cautioned against the development of adverse reactions, such as infections. It is essential to carefully select patients eligible for treatment with infliximab based on the guidelines established by the Japan College of Rheumatology, and adverse reactions to the drug should be prevented or detected early and treated promptly.

Rotational acetabular osteotomy for habitual hip dislocation with posterior acetabular wall deficiency in patients with Down syndrome

Hip dislocation associated with Down syndrome is relatively rare. Hip dislocation can progress to severe subluxation or habitual dislocation if the initial therapy is improperly performed. However, definitive treatment guidelines for conservative and surgical therapy for hip dislocation in patients with Down syndrome have not been established. This article describes a case of a 12-year-old girl with Down syndrome with nontraumatic habitual hip dislocation. Her hip joint was associated with acetabular dysplasia and hypoplasia of the posterior acetabular wall. Although conservative therapy was initially performed, no effects were observed. Rotational acetabular osteotomy and capsular plication were performed to reconstruct the posterior acetabular wall. No postoperative redislocation occurred, and the treatment effects were favorably sustained for 2 years. In Down syndrome, few cases of developmental dysplasia and hypoplasia of the posterior acetabular wall have been reported. In previous reports, these morphological abnormalities were rarely taken into consideration when determining the treatment strategy, and to our knowledge, no other reports demonstrate therapy involving rotational acetabular osteotomy for hip dislocation complicated with Down syndrome. Whether the acetabulum had posterior wall deficiency was thought to be important for conservative and surgical therapies in hip dislocation in patients with Down syndrome. Rotational acetabular osteotomy could be an effective surgical procedure for reconstruction of the acetabulum by posterolateral rotation of the osteotomized acetabulum.

Regulation of nitric oxide generation by up-regulated arginase I in rat spinal cord injury

Recently, arginase is suggested to regulate nitric oxide production by competing with nitric oxide synthase for the same substrate, L-arginine, in experimental asthma. We investigated the role of arginase and its relationship to nitric oxide production after spinal cord injury. Rats were subjected to laminectomy and complete transection of their spinal cords (injury group) or laminectomy only (sham group). In the injury group, arginase I was increased in the macrophages at the transection edge, and the peak was observed 48 h after spinal cord injury. However, nitric oxide production decreased significantly in the injury group despite increased nitric oxide synthase2 mRNA expression compared with the sham group. We also demonstrated the reduction in L-arginine concentrations, which was inversely associated with changes in arginase activity. Therefore, arginase appeared to regulate nitric oxide production by consuming L-arginine. The regulation of arginase activity and L-arginine levels may improve nitroxidative stress and reduce tissue damage in spinal cord injury.

Calcific myonecrosis of the lower leg: diagnosis and options of treatment

INTRODUCTION

Calcific myonecrosis is a rare condition characterized by a calcified lesion. Because this lesion sometimes presents as a huge mass with unique radiographic characteristics, it can be confused with soft tissue sarcoma. The appropriate treatment is still controversial. We report here three cases diagnosed as calcific myonecrosis of the lower leg and discuss its clinical presentation, diagnosis and options for treatment.

PATIENTS AND METHODS

Three patients presented as expanding masses in the anterior or lateral compartment muscle and occurred more than 10 years after an initial injury. Plain radiographs showed a large soft tissue mass with extensive amorphous calcifications. Computed tomograms revealed a low-density tumor with scattered calcifications. Magnetic resonance imaging showed a bright, high-signal area on T2-weighted imaging consistent with fluid. Two patients underwent excisions for histopathological evaluation and one was treated conservatively because of the absence of disability.

RESULTS

Two operative patients had no complication and the returned to work without evidence of deterioration of the disease. In a patient treated conservatively, the mass was not enlarged and was still painless at 2-year follow-up.

CONCLUSION

The key points for diagnosis were (1) amorphous liner calcification, (2) anterior or lateral compartment, (3) previous injury (several decades) of the tibia or femur, and (4) compartment syndrome. Although calcific myonecrosis is not commonly encountered, it must be considered in the differential diagnosis of an expanding intramuscular mass. In asymptomatic masses where the diagnosis is recognized, observation may be possible and unnecessary aggressive surgical intervention should be avoided.

Preparation and Characterization of a Polyclonal Antibody against Brominated Protein

(Di)bromotyrosine is formed by the specific reaction of eosinophil peroxidase and can be used as an eosinophil activation marker. In the present study, an antibody for (di)bromotyrosine in proteins was prepared to investigate the pathogenesis of eosinophil-related diseases such as allergic responses. A rabbit polyclonal antibody was raised against brominated keyhole limpet hemocyanin. The specificity of the antiserum was investigated with an enzyme-linked immunosorbent assay (ELISA). The antiserum recognized brominated bovine serum albumin (BSA) and dibromotyrosine-conjugated BSA. The antiserum also reacted with chlorinated BSA and di-iodotyrosine-conjugated BSA. Moreover, the specificity of the antiserum was investigated using competitive ELISA. Dibromotyrosine and di-iodotyrosine inhibited the recognition of brominated BSA by the antiserum. However, the recognition of brominated BSA by the antiserum was not inhibited by bromotyrosine, chlorotyrosine, iodotyrosine, nitrotyrosine, aminotyrosine, phosphotyrosine, or tyrosine. These results suggested that the epitope of the antiserum is dihalogenated tyrosine. Immunohistochemically, the antiserum stained brominated rat eosinophils but not chlorinated or nitrated eosinophils. In conclusion, an antiserum for dihalogenated protein was prepared. It is expected that the antiserum will be useful for the analysis of the pathogenesis of allergic diseases such as asthma and atopic dermatitis.

High-grade L5 spondylolisthesis associated with dural ectasia in neurofibromatosis

A 15-year-old girl was admitted to our hospital with severe low back pain. She had scoliosis dextra and tight hamstrings. A plain radiograph showed high-grade L5 spondylolisthesis with vertebral scalloping from the fourth lumbar to the first sacral vertebra. L5 wide laminectomy and posterior lumbar interbody fusion by iliac bone graft was performed using the Galveston method of sacral fixation and a pedicle screw system. The rod and hook system was used from T9 to the bilateral iliac wing. We added posterolateral fusion from T10 to S1 by autograft and allograft. The patient became pain free and was able to return to student life. Three years after surgery, the radiographs demonstrated good bony fusion; however, careful long-term follow-up is needed.

[The choice of antibiotics for prophylaxis of postoperative infections in the field of orthopaedics. Clinical experience with cefoxitin]

The clinical effects of cefoxitin (CFX) were evaluated in the prophylaxis of postoperative infections in the field of orthopaedics. The clinical response was good in 46 out of 50 patients; an efficacy rate of 92%. Four patients (8%) who did not respond to CFX were suffering from infections due to Mycobacterium tuberculosis (1), suspected Pseudomonas aeruginosa (1), and infection of unknown organism (2). A review was also made of recent trends among clinically isolated bacterial strains and their susceptibility to antibiotics in the field of orthopaedics. CFX is recommended as an antibiotic of first choice for the prophylaxis of postoperative infections in the field of orthopaedics.