Modern femoral component design in total knee arthroplasty shows a lower patellar contact force during knee flexion compared with its predecessor

BACKGROUND

The relationship between the femoral component design in total knee arthroplasty (TKA) and the patellofemoral contact force, as well as the soft tissue balance, has not been well reported thus far.

METHODS

Twenty-eight mobile-bearing posterior-stabilized (PS) TKAs using the traditional model (PFC Sigma) and 27 mobile-bearing PS TKAs using the latest model (Attune) were included. Surgeries were performed using the measured resection technique assisted with the computed tomography (CT)-based free-hand navigation system. After all the trial components were placed, patellar contact forces on the medial and lateral sides were measured using two uniaxial ultrathin force transducers with the knee at 0°, 10°, 30°, 60°, 90°, 120°, and 135° of flexion. The joint component gap and the varus ligament balance of the femorotibial joint were also measured. The non-paired Student's t-test was conducted to compare the values of the two groups.

RESULTS

The medial patellar contact force was significantly lower for Attune group than for PFC Sigma group at 120° of knee flexion (P = 0.0058). The lateral patellar contact force was also significantly lower for Attune group than PFC Sigma group at 120° and 135° of knee flexion (P = 0.0068 and P = 0.036). The joint component gap, as well as the varus ligament balance, showed no statistically significant difference between the two groups.

CONCLUSIONS

Reduced thickness and width of the anterior flange of the femoral component in the Attune may play a role in low patellar contact force.

The quantitative evaluation of anterior drawer test using an electromagnetic measurement system

The anterior drawer test (ADT) is the gold standard examination for the diagnosis of anterior talofibular ligamentinsufficiency,although there is noquantitative evaluation of ADT that is generally usable and reliable.An electromagnetic sensor (EMS)has been used to quantitatively evaluate joint kinematics, and has a high potential to be applied to the ankle joint. The aim of this study was to validatethe EMS measurement of the ADTin comparison to the fluoroscopic evaluationand to evaluate the reproducibility of the EMS measurement.Six feet were included,and an examinerperformed the ADT5 times for each foot while the anterior translation of the ankle jointwas quantitative evaluatedusing EMS and fluoroscope simultaneously. The anterior translation of the ankle joint during the ADT in EMS and in fluoroscope was 8.1 ± 5.7 mm and 3.6 ± 2.4 mm.Astrong correlation was observed between the measurements using EMS and fluoroscope (p < 0.01, the correlation coefficient = 0.91). Another 20 feet were included, and three examiners performed the ADT five times for each foot with the EMS measurement. The intra and inter-examiner reliability was 0.99 and 0.89.The EMS could quantify the anterior translation during the ADT which corresponds to fluoroscopic evaluation.

Clinical experience of the use of reamer irrigator aspirator in Japanese patients: A report of the first 42 cases

BACKGROUND

A reamer irrigator aspirator (RIA) can be used to harvest substantial amounts of autologous bone and debride the intramedullary canal. Clinical experience using reamer irrigator aspirators in Japan is very limited. The applicability of the reamer irrigator aspirator head with a minimum diameter of 12 mm for Japanese people is often questioned as the Japanese are smaller than Americans and Europeans. There are no reports of complications in Japanese patients. This study aimed to retrospectively review clinical cases and describe reamer irrigator aspirator use in Japanese patients.

METHODS

All patients for whom a reamer irrigator aspirator was used during surgery at our hospital between January 2014 and September 2018 were included. The patients' clinical and radiographic data were retrospectively reviewed.

RESULTS

Data of 40 patients (42 cases) were collected. The reamer irrigator aspirator was used for bone graft harvesting in 32 cases, intramedullary debridement and irrigation in 9 cases, and reaming for exchange nailing in 1 case. The diameter of the reamer irrigator aspirator reamer head was 12 mm in 22 cases (53.7%), 12.5 mm in 4 cases (9.8%), 13 mm in 9 cases (22.0%), 13.5 mm in 1 case (2.4%), 14.0 mm in 1 case (2.4%), 14.5 mm in 1 case (2.4%), and 15 mm in 4 cases (9.8%). Mean intraoperative bleeding volume was 1158.6 mL (range, 100-3800 mL). We experienced no difficulty inserting the reamer irrigator aspirator into the intramedullary canals and no cases of insertion-related intraoperative fracture. Five cortical perforations (11.9%) were observed on postoperative computed tomography scans, although no patient was symptomatic. One case (2.4%) of postoperative femur fracture occurred.

CONCLUSIONS

Reamer irrigator aspirators can be used in Japanese patients. Smaller reamer head sizes were mainly used in our experience. We should manage complications as in previous reports from Western countries.

Histological analysis of induced membranes in patients whose bone defects were treated with the Masquelet technique to identify factors affecting the vascularity of induced membranes

Background

Rich vascularity of the induced membrane (IM) is important for Masquelet reconstruction surgery. The factors affecting IM vascularity are not completely understood. This study aimed to investigate these factors using histological samples of human IMs.

Methods

We retrospectively evaluated 36 patients whose bone defects were treated using the Masquelet technique. Two clinical pathologists analyzed histological sections of IM pieces (1 cm²). The number of blood vessels per 1 mm² was counted and compared among men and women, femur or tibia, with and without free flap surgery, antibiotic impregnation to the cement, osteogenesis inside the membrane, smoking, and diabetes mellitus. The number of blood vessels within the same patient was compared among different time points. Correlation analysis was performed among blood vessel numbers and patient age, duration of cement spacer placement, and histological grading scales (inflammation, foreign body reaction, and fibrosis).

Results

IM formation with rich vascularity and some inflammation, foreign body reaction, and fibrosis were histologically confirmed in all patients. We found 37.4 ± 19.1 blood vessels per 1 mm². The number of blood vessels was significantly lower in patients with than in those without free flap surgery; it was higher in patients with osteogenesis inside the IM. No significant correlations were found in any of the analyses.

Conclusion

Sex, patient age, smoking, diabetes mellitus, femur or tibia, duration of cement spacer placement, and antibiotic impregnation to the cement did not affect IM vascularization. IM vascularization was reduced in patients with than in those without free flap surgery.

Anterior placement of the talar component in total ankle arthroplasty: A risk factor for talar component subsidence

BACKGROUND

Component subsidence is considered as a cause of revision surgery. The talar component subsidence may be a risk factor for revision surgery; however, there are no reports regarding talar component placement and subsidence amount following total ankle arthroplasty (TAA). We therefore investigated the relationship between talar component placement and subsidence amount.

METHODS

Fifty-two ankles from 49 patients (age: 71 years [range 62-83], 13 male/ 36 female), who underwent TAA with mean follow-up of 36 months (range 12-83), were included. The subjects were divided into two groups based on talar component placement: anterior placement (n = 20, group A) and posterior placement (n = 32, group P) using weight-bearing lateral plain radiographs. The amount of the talar component subsidence and clinical outcomes, which included the Japanese Society for Surgery of the Foot (JSSF) scale, range of the motion (ROM) and the revision rate, were compared between the groups.

RESULTS

Talar component subsidence was significantly higher in group A (2.1 ± 2.0 mm) than in group P (0.6 ± 1.4 mm, P = .017). There was no significant difference in the JSSF scale and ROM between group A and group P. The revision rate was 10.0% in group A and 6.3% in group P, albeit not statistically significant.

CONCLUSION

Greater talar component subsidence was observed when the talar component was placed more anteriorly, suggesting that anterior placement of the talar component may need to be avoided during the surgery in order to minimize the postoperative talar component subsidence.

Differences in preoperative planning for high-tibial osteotomy between the standing and supine positions

Introduction

Previous studies have reported that alignment changes depend on the patient’s position in orthopedic surgery. However, it has not yet been well examined how the patient’s position affects the preoperative planning in high-tibial osteotomy (HTO). Therefore, the aim of this study was to investigate the effects of the patient’s position on preoperative planning in HTO.

Materials and methods

A total of 60 knees in 55 patients who underwent HTO were retrospectively examined. Virtual preoperative planning for medial open-wedge HTO (OWHTO), lateral closed-wedge HTO (CWHTO), and hybrid CWHTO were performed by setting the percentage of the weight-bearing line (%WBL) at 62% as an optimal alignment. The correction angle differences between the supine and standing radiographs were measured. The virtual %WBL (v%WBL) was determined by applying the correction angle obtained from the standing radiograph to the supine radiograph. The %WBL discrepancy (%WBLd) was calculated as v%WBL − 62 (%) to predict the possible correction errors during surgeries. A single regression analysis was performed to examine the correlation between the correction angle difference and %WBLd.

Results

The mean correction angle was significantly higher when the preoperative planning was based on standing radiographs than when based on supine radiographs (P < 0.001), and the mean difference was 2.2 ± 1.5°. The difference between the two conditions in the medial opening gaps for OWHTO, lateral wedge sizes (mm) for CWHTO, and hybrid CWHTO were 2.6 ± 2.0, 2.3 ± 1.6, and 1.9 ± 1.4, respectively. The mean v%WBL was 71.2% ± 7.3%, and the mean %WBLd was 10.1% ± 7.4%. A single regression analysis revealed a linear correlation between the correction angle difference and %WBLd (%WBLd = 4.72 × correction angle difference + 0.08). No statistically significant difference in the parameters was found between the supine and standing radiographs postoperatively.

Conclusions

We found significant differences in the estimated correction angles between the supine and standing radiographs in the planning for HTO. Therefore, surgeons should carefully consider the difference between supine and standing radiographs and estimate the possible correction error during surgery when planning a HTO.

Surgical outcomes of metastatic bone tumors in the extremities (Surgical outcomes of bone metastases)

•

Prognostic factors: primary tumor, visceral metastases, and surgical procedure.

•

PS, BI, EQ-5D, and NRS improved at 3 months after surgery.

•

The improvements of PS, BI, EQ-5D, and NRS were maintained for 6 M after surgery.

•

The management of bone metastases must be decided by a multidisciplinary team.

•

The proper management of bone metastasis will reduce postoperative complications.

Background

Skeletal related events due to metastatic bone tumors markedly affect the activities of daily living (ADL) and quality of life (QOL) in cancer patients. We focused on multidisciplinary therapy for metastatic bone tumors. This study aimed to evaluate the outcomes of surgical treatment for metastatic bone tumors in the extremities.

Methods

We retrospectively reviewed 114 patients who underwent surgical treatment for metastatic bone tumors of the extremities between 2008 and 2019 and 69 patients were reassessed for more than 6 months after surgery. The most common primary tumor was renal, followed by lung, thyroid, and breast cancers. We assessed 69 patients’ performance status (PS), Barthel Index (BI) for ADL, EuroQol 5 Dimensions (EQ-5D) for QOL, and numerical rating scale (NRS) for pain and analyzed these postoperative values relative to preoperative values using Friedman’s test. The postoperative overall survival and the prognostic factors were evaluated using the Kaplan-Meier method, the log-rank test and Cox proportional hazards analysis.

Results

The 1-year overall survival rate was 59%, and the median survival time after surgery was 20 months. Primary tumor, visceral metastasis, and surgical procedure were risk factors correlated with overall survival. PS, BI, EQ-5D, and NRS improved at 3 months after surgery and these improvements were maintained for 6 months after surgery regardless of the surgical procedure.

Conclusions

The significant factors affecting survival after surgical treatment for bone metastases included the primary tumor, presence of visceral metastases, and internal fixation without tumor resection or curettage. Surgical treatment for metastatic bone tumors effectively reduced pain and improved PS, ADL, and QOL postoperatively after 3 months.

Clinical Outcome of the Patients With Brain Metastasis from Soft Tissue Sarcomas

BACKGROUND/AIM

This study aimed to evaluate the association of clinical characteristics with treatment outcomes to ascertain the appropriate treatment options for soft tissue sarcomas (STS) patients with brain metastasis (BM).

PATIENTS AND METHODS

Medical records of STS patients with BM who were treated in our institutions were retrospectively reviewed, and analyzed to identify the factors associated with post-BM survival.

RESULTS

Among the 509 STS patients, BM occurred in five patients (0.98%). The median survival after BM was 1.5 months. Histological subtypes of the primary lesions in the five BM patients were: two synovial sarcomas, one myxoid liposarcoma, one alveolar soft part sarcoma, and one rhabdomyosarcoma. Among the five BM patients, the post-BM survival of two patients, who underwent surgery and postoperative radiotherapy, was longer than that of the other patients (p<0.01).

CONCLUSION

Combined surgery and postoperative radiotherapy effectively managed symptoms and prolonged survival in STS patients with BM.

Cryopreserved human adipose-derived stromal vascular fraction maintains fracture healing potential via angiogenesis and osteogenesis in an immunodeficient rat model

Background

Novel therapeutic strategies for the healing of nonunion, which has serious effects on the quality of life of patients, are needed. We evaluated the therapeutic effect of local transplantation of human stromal vascular fraction (SVF) cells on fracture healing in a rat non-healing fracture model and compared the effects between freshly isolated (F) and cryopreserved (C)-SVFs.

Methods

Non-healing fracture model was induced in the femur of female immunodeficient rats (F344/N Jcl rnu/rnu) with cauterizing periosteum. Immediately after the creation of non-healing fracture, rats received local transplantation of F and C-SVFs suspended in phosphate-buffered saline (PBS) or the same volume of PBS without cells using the same scaffold as a control group. During 8 weeks post-surgery, radiologic, histological, immunohistochemical, and biomechanical analyses were performed to evaluate fracture healing. The comparison of radiological results was performed with a chi-square test, and the multiple comparisons of immunohistochemical, histological, and biomechanical results among groups were made using a one-way analysis of variance. A probability value of 0.05 was considered to denote statistical significance.

Results

At week 8, in 60% of animals receiving F-SVF cells and in 50% of animals receiving C-SVF cells, the fracture radiologically healed with bone union whereas nonunion was observed in the control group. The healing potential was also confirmed by histological and biomechanical assessments. One of the mechanisms underlying healing involving intrinsic angiogenesis/osteogenesis was enhanced in F- and C-SVF groups compared with that in the control group. Human cell-derived vasculogenesis/osteogenesis, which was also confirmed in an in vitro differentiation assay, was also enhanced in the F- and C-SVF groups compared with that in the control groups and could be another mechanism for healing.

Conclusions

SVF cells can enhance bone healing and cryopreserved cells have almost equal potential as fresh cells. SVF cells can be used for improving nonunion bone fracture healing as an alternative to other mesenchymal stem cells and the effect of SVF cells can be maintained under cryopreservation.

The sagittal cutting plane affects evaluation of the femoral bone tunnel position on three-dimensional computed tomography after anterior cruciate ligament reconstruction

PURPOSE

To investigate how the femoral sagittal cutting plane affects evaluation of the bone tunnel position after anterior cruciate ligament (ACL) reconstruction using the quadrant method in three-dimensional computed tomography (CT) imaging.

METHODS

Thirty patients who underwent primary anatomic double-bundle ACL reconstruction and CT 2 weeks after surgery were enrolled. Three sagittal cutting planes with respect to the condylar axis were created using the CT images: at the top of the intercondylar notch (C-plane), 5% medial (M-plane), and 5% lateral (L-plane). The center of the bone tunnel position regarding depth and height of the anteromedial (AMB) and posterolateral bundle (PLB) were quantitatively evaluated using the quadrant method on the three different planes.

RESULTS

The mean depths of AMB and PLB were 27.4 ± 4.4% and 39.7 ± 5.1%, 27.0 ± 4.2% and 37.6 ± 4.9%, and 27.4 ± 4.5% and 38.5 ± 6.0%, at the M, C and L planes, respectively. The mean heights of AMB and PLB were 30.8 ± 6.3% and 56.2 ± 5.6%, 30.4 ± 6.2% and 56.6 ± 5.6%, and 25.4 ± 7.0% and 52.9 ± 6.9% at the M, C, and L planes, respectively. Both AMB and PLB bone tunnels were evaluated as higher positions in the L-plane than the C-plane (p < 0.01, p = 0.02, respectively) and M-plane (p < 0.01, p = 0.04, respectively), but there were no significant differences between the C-plane and M-plane (n.s.). There was no significant difference in the anteroposterior direction for all planes.

CONCLUSION

In evaluations of the bone tunnel position with the quadrant method using three-dimensional CT, the bone tunnel position depends on the femoral sagittal cutting plane. A consistent evaluation method should be used when evaluating the bone tunnel position after ACL reconstruction to enable correct evaluation clinically.

LEVEL OF EVIDENCE

Case-control study, Level III.

Comparison of Clinical and Imaging Outcomes of Different Doses of Adipose-Derived Stromal Vascular Fraction Cell Treatment for Knee Osteoarthritis

Favorable clinical outcomes of intra-articular injection of adipose-derived stromal vascular fraction (SVF) cells for knee osteoarthritis (OA) have been reported, but the effects of different doses of SVF cells have not been examined. This study aimed to compare the short-term clinical and imaging outcomes of different doses of SVF cells for knee OA treatment. This study included 60 patients with knee OA who underwent intra-articular injection of SVF cells. The follow-up period was at least 12 months. Thirty patients received an intra-articular injection of 2.5×10⁷ SVF cells (low-dose group), and the remaining 30 patients received an intra-articular injection of 5.0×10⁷ SVF cells (high-dose group). Clinical evaluations were performed for the Knee injury and Osteoarthritis Outcome Score (KOOS). Imaging evaluations, including the magnetic resonance imaging Osteoarthritis Knee Score (MOAKS) features (bone marrow lesions, cartilage defects, osteophytes, Hoffa’s synovitis, and effusion synovitis), were also performed. All clinical and imaging evaluations were performed preoperatively and 12 months postoperatively and compared between the groups. In demographic data, no significant differences were found between the two groups. The total score of KOOS at 12 months postoperatively was significantly more favorable than the preoperative score in the high-dose groups. Pain and symptoms subscale scores of KOOS at 12 months postoperatively were significantly better in the high-dose group than in the low-dose group. The bone marrow lesions, Hoffa’s synovitis, and effusion synovitis improved approximately 30–40% at 12 months postoperatively compared to baseline in both groups. However, there were no significant differences in imaging evaluations between the two groups. In conclusion, the pain and symptoms subscale scores of KOOS from baseline to 12 months postoperatively improved better in the high-dose group than in the low-dose group. Our findings suggest that intra-articular injection of SVF cells for knee OA is an innovative approach.

Transcutaneous CO2 application accelerates fracture repair in streptozotocin-induced type I diabetic rats

INTRODUCTION

Diabetes mellitus (DM) negatively affects fracture repair by inhibiting endochondral ossification, chondrogenesis, callus formation, and angiogenesis. We previously reported that transcutaneous CO₂ application accelerates fracture repair by promoting endochondral ossification and angiogenesis. The present study aimed to determine whether CO₂ treatment would promote fracture repair in cases with type I DM.

RESEARCH DESIGN AND METHODS

A closed femoral shaft fracture was induced in female rats with streptozotocin-induced type I DM. CO₂ treatment was performed five times a week for the CO₂ group. Sham treatment, where CO₂ was replaced with air, was performed for the control group. Radiographic, histologic, genetic, and biomechanical measurements were taken at several time points.

RESULTS

Radiographic assessment demonstrated that fracture repair was induced in the CO₂ group. Histologically, accelerated endochondral ossification and capillary formation were observed in the CO₂ group. Immunohistochemical assessment indicated that early postfracture proliferation of chondrocytes in callus was enhanced in the CO₂ group. Genetic assessment results suggested that cartilage and bone formation, angiogenesis, and vasodilation were upregulated in the CO₂ group. Biomechanical assessment revealed enhanced mechanical strength in the CO₂ group.

CONCLUSIONS

Our findings suggest that CO₂ treatment accelerates fracture repair in type I DM rats. CO₂ treatment could be an effective strategy for delayed fracture repair due to DM.

Suitability of pepper mild mottle virus as a human enteric virus surrogate for assessing the efficacy of thermal or free-chlorine disinfection processes by using infectivity assays and enhanced viability PCR

Evaluating the efficacy of disinfection processes to inactivate human enteric viruses is important for the prevention and control of waterborne diseases caused by exposure to those viruses via drinking water. Here, we evaluated the inactivation of two representative human enteric viruses (adenovirus type 40 [AdV] and coxsackievirus B5 [CV]) by thermal or free-chlorine disinfection. In addition, we compared the infectivity reduction ratio of a plant virus (pepper mild mottle virus [PMMoV], a recently proposed novel surrogate for human enteric viruses for the assessment of virus removal by coagulation‒rapid sand filtration and membrane filtration) with that of the two human enteric viruses to assess the suitability of PMMoV as a human enteric virus surrogate for use in thermal and free-chlorine disinfection processes. Finally, we examined whether conventional or enhanced viability polymerase chain reaction (PCR) analysis using propidium monoazide (PMA) or improved PMA (PMAxx) with or without an enhancer could be used as alternatives to infectivity assays (i.e., plaque-forming unit method for AdV and CV; local lesion count assay for PMMoV) for evaluating virus inactivation by disinfection processes. We found that PMMoV was more resistant to heat treatment than AdV and CV, suggesting that PMMoV is a potential surrogate for these two enteric viruses with regard to thermal disinfection processes. However, PMMoV was much more resistant to chlorine treatment compared with AdV and CV (which is chlorine-resistant) (CT value for 4-log₁₀ inactivation: PMMoV, 84.5 mg-Cl₂·min/L; CV, 1.15-1.19 mg-Cl₂·min/L), suggesting that PMMoV is not useful as a surrogate for these enteric viruses with regard to free-chlorine disinfection processes. For thermal disinfection, the magnitude of the signal reduction observed with PMAxx-Enhancer-PCR was comparable with the magnitude of reduction in infectivity, indicating that PMAxx-Enhancer-PCR is a potential alternative to infectivity assay. However, for free-chlorine disinfection, the magnitude of the signal reduction observed with PMAxx-Enhancer-PCR was smaller than the magnitude of the reduction in infectivity, indicating that PMAxx-Enhancer-PCR underestimated the efficacy of virus inactivation (i.e., overestimated the infectious virus concentration) by chlorine treatment. Nevertheless, among the PCR approaches examined in the present study (PCR alone, PMA-PCR or PMAxx-PCR either with or without enhancer), PMAxx-Enhancer-PCR provided the most accurate assessment of the efficacy of virus inactivation by thermal or free chlorine disinfection processes.

Acquisition of cancer stem cell properties in osteosarcoma cells by defined factors

Background

Cancer stem cells (CSCs) are considered to be responsible for tumor initiation, formation, and poor prognosis of cancer patients. However, the rarity of CSCs in clinical samples makes it difficult to elucidate characteristics of CSCs, especially in osteosarcoma (OS). The aim of this study is to verify whether it is possible to generate CSC-like cells by transducing defined factors into an OS cell line.

Methods

We retrovirally transduced the Octamer-binding transcription factor 3/4 (OCT3/4), Kruppel-like factor 4 (KLF4), and SRY-box transcription factor 2 (SOX2) genes into the MG-63 human OS cell line (MG-OKS). Parental and GFP-transduced MG-63 cells were used as negative control. We assessed the properties of the generated cells in vitro and in vivo. Multiple comparisons among groups were made using a one-way analysis of variance (ANOVA) followed by post hoc testing with Tukey’s procedure.

Results

MG-OKS cells in vitro exhibited the significantly increased mRNA expression levels of CSC markers (CD24, CD26, and CD133), decreased cell growth, increased chemoresistance and cell migration, and enhanced sphere formation. Notably, MG-OKS cells cultured under osteogenic differentiation conditions showed strongly positive staining for both Alizarin Red S and alkaline phosphatase, indicating osteogenesis of the cells. Gene ontology analysis of microarray data revealed significant upregulation of epidermal-related genes. Tumors derived from MG-OKS cells in vivo were significantly larger than those from other cells in μCT analysis, and immunohistochemical staining showed that Ki-67, osteocalcin, and HIF-1α-positive cells were more frequently detected in the MG-OKS-derived tumors.

Conclusions

In this study, we successfully generated OS CSC-like cells with significantly enhanced CSC properties following transduction of defined factors.

Conventional computed tomography software can be used for accurate pre-operative templating in bipolar hip arthroplasty: A preliminary report

BACKGROUND

The aim of this study was to investigate the use of pre-operative templating for bipolar hip arthroplasty (BHA) for displaced femoral neck fracture using multiplanar reconstruction (MPR) of computed tomography (CT) images.

METHODS

Nineteen patients who underwent BHA were enrolled in this study. For pre- and post-operative evaluation, a CT scan was performed from the pelvis to the knee joints. MPR of the CT image was done using software to measure the femoral head cup diameter, offset, stem size, length of the modular neck, distance from the neck osteotomy, and femoral anteversion. We compared these parameters pre- and post-operatively.

RESULTS

Both the femoral head cup diameter and length of the modular neck were found to be significantly different between pre- and post-operative measurements, although the differences were minor. Other parameters, including the femoral offset, were not significantly different between the pre- and post-operative measurements. The size of the femoral stem, cup diameter, and length of the modular neck were consistent with the planned size and accurate (within ±1 size) in more than 84% cases.

CONCLUSION

Our pre-operative templating approach for BHA using MPR of CT has potential clinical utility as a complementary tool for pre-operative planning using three-dimensional templating software. Moreover, this technique could be feasible in most hospitals without additional expenditure.

Effects of the duration of transcutaneous CO2 application on the facilitatory effect in rat fracture repair

BACKGROUND

Carbon dioxide therapy has been reported to be effective in treating certain cardiac diseases and skin problems. Although a previous study suggested that transcutaneous carbon dioxide application accelerated fracture repair in association with promotion of angiogenesis, blood flow, and endochondral ossification, the influence of the duration of carbon dioxide application on fracture repair is unknown. The aim of this study was to investigate the effect of the duration of transcutaneous carbon dioxide application on rat fracture repair.

METHODS

A closed femoral shaft fracture was created in each rat. Animals were randomly divided into four groups: the control group; 1w-CO₂ group, postoperative carbon dioxide treatment for 1 week; 2w-CO₂ group, postoperative carbon dioxide treatment for 2 weeks; 3w-CO₂ group, postoperative carbon dioxide treatment for 3 weeks. Transcutaneous carbon dioxide application was performed five times a week in the carbon dioxide groups. Sham treatment, where the carbon dioxide was replaced with air, was performed for the control group. Radiographic, histological, and biomechanical assessments were performed at 3 weeks after fracture.

RESULTS

The fracture union rate was significantly higher in the 3w-CO₂ group than in the control group (p < 0.05). Histological assessment revealed promotion of endochondral ossification in the 3w-CO₂ group than in the control group. In the biomechanical assessment, all evaluation items related to bone strength were significantly higher in the 3w-CO₂ group than in the control group (p < 0.05).

CONCLUSIONS

The present study, conducted using an animal model, demonstrated that continuous carbon dioxide application throughout the process of fracture repair was effective in enhancing fracture healing.

Exploratory clinical trial on the safety and bactericidal effect of 222-nm ultraviolet C irradiation in healthy humans

Introduction

Surgical site infection is one of the most severe complications of surgical treatments. However, the optimal procedure to prevent such infections remains uninvestigated. Ultraviolet radiation C (UVC) with a short wavelength has a high bactericidal effect; however, it is cytotoxic. Nonetheless, given that UVC with a wavelength of 222 nm reaches only the stratum corneum, it does not affect the skin cells. This study aimed to investigate the safety of 222-nm UVC irradiation and to examine its skin sterilization effect in healthy volunteers.

Methods

This trial was conducted on 20 healthy volunteers. The back of the subject was irradiated with 222-nm UVC at 50–500 mJ/cm², and the induced erythema (redness of skin) was evaluated. Subsequently, the back was irradiated with a maximum amount of UVC not causing erythema, and the skin swabs before and after the irradiation were cultured. The number of colonies formed after 24 hours was measured. In addition, cyclobutene pyrimidine dimer (CPD) as an indicator of DNA damage was measured using skin tissues of the nonirradiated and irradiated regions.

Results

All subjects experienced no erythema at all doses. The back of the subject was irradiated at 500 mJ/cm², and the number of bacterial colonies in the skin swab culture was significantly decreased by 222-nm UVC irradiation. The CPD amount produced in the irradiated region was slightly but significantly higher than that of the non-irradiated region.

Conclusion

A 222-nm UVC at 500 mJ/cm² was a safe irradiation dose and possessed bactericidal effects. In the future, 222-nm UVC irradiation is expected to contribute to the prevention of perioperative infection.

Intraoperative Soft Tissue Balance/Kinematics and Clinical Evaluation of Modified Kinematically versus Mechanically Aligned Total Knee Arthroplasty

Recently, kinematically aligned total knee arthroplasty has been found to achieve better clinical outcomes than mechanically aligned TKA. Despite the good clinical outcomes that are reported at short- to mid-term follow-up, intraoperative variables that are associated with a better outcome have not been measured. Therefore, this study was conducted to compare intraoperative kinematics/soft tissue balance and the clinical outcomes of patients who underwent modified kinematically (restricted tibial cut) or mechanically aligned total knee arthroplasty. Sixty cruciate-retaining total knee arthroplasties (30 modified kinematically [3-degree varus and 7-degree posterior slope in tibial cut] and 30 mechanically aligned) were performed in patients with varus-type osteoarthritis using a navigation system. Intraoperative kinematics assessed by the navigation system and soft tissue balance assessed by an offset-type tensor were compared between the groups. One year postoperatively, the range of motion and 2011 Knee Society scores were compared between the groups. Kinematic assessment exhibited that tibial internal rotation during flexion was significantly maintained in the kinematic compared with the mechanical group (p < 0.05). Varus/valgus ligament balance at 90 and 120 degrees of flexion significantly maintained lateral laxity in the kinematic compared with the mechanical group (p < 0.05). Improvement of flexion angles, functional activity scores, and patient satisfaction were significantly better in the kinematic than in the mechanical group (p < 0.05). Modified kinematically aligned cruciate-retaining total knee arthroplasty maintained more tibial internal rotation and lateral laxity during flexion than mechanically aligned total knee arthroplasty; thus, the former may result in better clinical outcomes.

Percutaneous CO2 Treatment Accelerates Bone Generation During Distraction Osteogenesis in Rabbits

BACKGROUND

Distraction osteogenesis has been broadly used to treat various structural bone deformities and defects. However, prolonged healing time remains a major problem. Various approaches including the use of low-intensity pulsed ultrasound, parathyroid hormone, and bone morphogenetic proteins (BMPs) have been studied to shorten the treatment period with limited success. Our previous studies of rats have reported that the transcutaneous application of CO2 accelerates fracture repair and bone-defect healing in rats by promoting angiogenesis, blood flow, and endochondral ossification. This therapy may also accelerate bone generation during distraction osteogenesis, but, to our knowledge, no study investigating CO2 therapy on distraction osteogenesis has been reported.

QUESTIONS/PURPOSES

We aimed to investigate the effect of transcutaneous CO2 during distraction osteogenesis in rabbits, which are the most suitable animal as a distraction osteogenesis model for a lengthener in terms of limb size. We asked: Does transcutaneous CO2 during distraction osteogenesis alter (1) radiographic bone density in the distraction gap during healing; (2) callus parameters, including callus bone mineral content, volumetric bone mineral density, and bone volume fraction; (3) the newly formed bone area, cartilage area, and angiogenesis, as well as the expression of interleukin-6 (IL-6), BMP-2, BMP-7, hypoxia-inducible factor (HIF) -1α, and vascular endothelial growth factor (VEGF); and (4) three-point bend biomechanical strength, stiffness, and energy?

METHODS

Forty 24-week-old female New Zealand white rabbits were used according to a research protocol approved by our institutional ethical committee. A distraction osteogenesis rabbit tibia model was created as previously described. Briefly, an external lengthener was applied to the right tibia, and a transverse osteotomy was performed at the mid-shaft. The osteotomy stumps were connected by adjusting the fixator to make no gap. After a 7-day latency phase, distraction was continued at 1 mm per day for 10 days. Beginning the day after the osteotomy, a 20-minute transcutaneous application of CO2 on the operated leg using a CO2 absorption-enhancing hydrogel was performed five times per week in the CO2 group (n = 20). Sham treatment with air was administered in the control group (n = 20). Animals were euthanized immediately after the distraction period (n = 10), 2 weeks (n = 10), and 4 weeks (n = 20) after completion of distraction. We performed bone density quantification on the plain radiographs to evaluate consolidation in the distraction gap with image analyzing software. Callus parameters were measured with micro-CT to assess callus microstructure. The newly formed bone area and cartilage area were measured histologically with safranin O/fast green staining to assess the progress of ossification. We also performed immunohistochemical staining of endothelial cells with fluorescein-labeled isolectin B4 and examined capillary density to evaluate angiogenesis. Gene expressions in newly generated callus were analyzed by real-time polymerase chain reaction. Biomechanical strength, stiffness, and energy were determined from a three-point bend test to assess the mechanical strength of the callus.

RESULTS

Radiographs showed higher pixel values in the distracted area in the CO2 group than the control group at Week 4 of the consolidation phase (0.98 ± 0.11 [95% confidence interval 0.89 to 1.06] versus 1.19 ± 0.23 [95% CI 1.05 to 1.34]; p = 0.013). Micro-CT demonstrated that bone volume fraction in the CO2 group was higher than that in the control group at Week 4 (5.56 ± 3.21 % [95% CI 4.32 to 6.12 %] versus 11.90 ± 3.33 % [95% CI 9.63 to 14.25 %]; p = 0.035). There were no differences in any other parameters (that is, callus bone mineral content at Weeks 2 and 4; volumetric bone mineral density at Weeks 2 and 4; bone volume fraction at Week 2). At Week 2, rabbits in the CO2 group had a larger cartilage area compared with those in the control group (2.09 ± 1.34 mm [95% CI 1.26 to 2.92 mm] versus 5.10 ± 3.91 mm [95% CI 2.68 to 7.52 mm]; p = 0.011). More newly formed bone was observed in the CO2 group than the control group at Week 4 (68.31 ± 16.32 mm [95% CI 58.19 to 78.44 mm] versus 96.26 ± 19.37 mm [95% CI 84.25 to 108.26 mm]; p < 0.001). There were no differences in any other parameters (cartilage area at Weeks 0 and 4; newly formed bone area at Weeks 0 and 2). Immunohistochemical isolectin B4 staining showed greater capillary densities in rabbits in the CO2 group than the control group in the distraction area at Week 0 and surrounding tissue at Weeks 0 and 2 (distraction area at Week 0, 286.54 ± 61.55 /mm [95% CI 232.58 to 340.49] versus 410.24 ± 55.29 /mm [95% CI 361.78 to 458.71]; p < 0.001; surrounding tissue at Week 0 395.09 ± 68.16/mm [95% CI 335.34 to 454.83] versus 589.75 ± 174.42/mm [95% CI 436.86 to 742.64]; p = 0.003; at Week 2 271.22 ± 169.42 /mm [95% CI 122.71 to 419.73] versus 508.46 ± 49.06/mm [95% CI 465.45 to 551.47]; p < 0.001 respectively). There was no difference in the distraction area at Week 2. The expressions of BMP -2 at Week 2, HIF1-α at Week 2 and VEGF at Week 0 and 2 were greater in the CO2 group than in the control group (BMP -2 at Week 2 3.84 ± 0.83 fold [95% CI 3.11 to 4.58] versus 7.32 ± 1.63 fold [95% CI 5.88 to 8.75]; p < 0.001; HIF1-α at Week 2, 10.49 ± 2.93 fold [95% CI 7.91 to 13.06] versus 20.74 ± 11.01 fold [95% CI 11.09 to 30.40]; p < 0.001; VEGF at Week 0 4.80 ± 1.56 fold [95% CI 3.43 to 6.18] versus 11.36 ± 4.82 fold [95% CI 7.13 to 15.59]; p < 0.001; at Week 2 31.52 ± 8.26 fold [95% CI 24.27 to 38.76] versus 51.05 ± 15.52 fold [95% CI 37.44 to 64.66]; p = 0.034, respectively). There were no differences in any other parameters (BMP-2 at Week 0 and 4; BMP -7 at Weeks 0, 2 and 4; HIF-1α at Weeks 0 and 4; IL-6 at Weeks 0, 2 and 4; VEGF at Week 4). In the biomechanical assessment, ultimate stress and failure energy were greater in the CO2 group than in the control group at Week 4 (ultimate stress 259.96 ± 74.33 N [95% CI 167.66 to 352.25] versus 422.45 ± 99.32 N [95% CI 299.13 to 545.77]; p < 0.001, failure energy 311.32 ± 99.01 Nmm [95% CI 188.37 to 434.25] versus 954.97 ± 484.39 Nmm [95% CI 353.51 to 1556.42]; p = 0.003, respectively). There was no difference in stiffness (216.77 ± 143.39 N/mm [95% CI 38.73 to 394.81] versus 223.68 ± 122.17 N/mm [95% CI 71.99 to 375.37]; p = 0.92).

CONCLUSION

Transcutaneous application of CO2 accelerated bone generation in a distraction osteogenesis model of rabbit tibias. As demonstrated in previous studies, CO2 treatment might affect bone regeneration in distraction osteogenesis by promoting angiogenesis, blood flow, and endochondral ossification.

CLINICAL RELEVANCE

The use of the transcutaneous application of CO2 may open new possibilities for shortening healing time in patients with distraction osteogenesis. However, a deeper insight into the mechanism of CO2 in the local tissue is required before it can be used in future clinical practice.

Insufficiency and deficiency of vitamin D in elderly patients with fragility fractures of the hip in the Japanese population

BACKGROUND

Data of vitamin D sufficiency in Asian patients with osteoporotic fragility hip fractures are limited. This study aimed to obtain data from the Japanese population.

METHODS

Patients aged 60 years or older with hip fractures were prospectively enrolled. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured. Levels were compared between patients receiving and not receiving treatment for osteoporosis, those with and without previous contralateral hip fractures, and those with femoral neck versus trochanteric fractures. Sex-based differences were also assessed. The serum levels in patients younger than 60 years with extremity fractures were assessed, and differences between elderly and younger patients were evaluated. The individual correlation between 25(OH)D levels and the ultraviolet (UV) index and age was analyzed in elderly patients with hip fractures.

RESULTS

The data of 360 patients (aged 84.7 ± 8.2 years), comprising 80 men and 280 women, were analyzed. The mean 25(OH)D level was 16.5 ± 7.2 ng/mL. The prevalence of vitamin D insufficiency (25(OH)D <30 ng/mL) and deficiency (25(OH)D <20 ng/mL) was 93.9% and 71.7%, respectively. A significant difference was noted in the prevalence of vitamin D deficiency between patients with and without previous contralateral hip fractures. Age and 25(OH)D levels were found to be correlated, with no correlation between the UV index and the 25(OH)D levels. The 25(OH)D level in the younger population (n = 123) was 20.7 ± 8.6 ng/mL, which was significantly higher than that of the elderly.

CONCLUSION

Perennial vitamin D insufficiency is prevalent in elderly Japanese patients with hip fractures.

Radial Meniscal Tears Are Best Repaired by a Modified "Cross" Tie-Grip Suture Based on a Biomechanical Comparison of 4 Repair Techniques in a Porcine Model

Background:

The tie-grip suture can fix radial tears more rigidly than simple conventional sutures. However, one shortcoming is the residual gap at the central margin of the tear. The tie-grip suture was modified to address this issue and named the “cross tie-grip suture.”

Purpose/Hypothesis:

The purpose of this study was to compare the suture stability and strength among 4 suturing techniques: the original tie-grip, cross tie-grip, and 2 conventional sutures (double horizontal and cross). It was hypothesized that the cross tie-grip suture would show the least displacement and resist the greatest maximum load.

Study Design:

Controlled laboratory study.

Methods:

A total of 40 fresh-frozen porcine knees were dissected to acquire 80 menisci; 20 menisci were tested in each suture group. A radial tear was created at the middle third of the meniscal body. Repair was performed with the following: original tie-grip, cross tie-grip, double horizontal, and cross sutures. The mechanical strength of sutured menisci was evaluated using a tensile testing machine. All menisci underwent submaximal loading and load to failure. The gap distance and ultimate failure load were compared using analysis of variance. The failure mode was recorded after load-to-failure testing.

Results:

Displacement after 500 cycles was significantly smaller in the cross tie-grip group (0.4 ± 0.3 mm) compared with the tie-grip (0.9 ± 0.6 mm), double horizontal (1.2 ± 0.7 mm), and cross suture groups (1.4 ± 0.6 mm) (P < .05). The ultimate failure load was significantly greater in the cross tie-grip (154.9 ± 29.0 N) and tie-grip (145.2 ± 39.1 N) groups compared with the double horizontal (81.2 ± 19.9 N) and cross suture groups (87.3 ± 17.7 N) (P < .05). Tissue failure was the most common mode of failure in all groups.

Conclusion:

Upon repair of radial meniscal tears, the cross tie-grip suture showed less displacement compared with that of the tie-grip, double horizontal, and cross sutures and demonstrated equivalent load to failure to that of the tie-grip suture at time zero.

Clinical Relevance:

The cross tie-grip suture provided high resistance to displacement after repair of radial tears and may be advantageous in healing for radial meniscal tears.

Plantar pressure sensors indicate women to have a significantly higher peak pressure on the hallux, toes, forefoot, and medial of the foot compared to men

Background

Sex-related differences of plantar pressure distribution during activities should be thoroughly inspected as it can help establish treatment and prevention strategies for foot and ankle problems. In-shoe measurement systems are preferable without space and activity restrictions; however, previously reported systems are still heavy and bulky and induce unnatural movement. Therefore, a slim and light plantar pressure sensor was newly developed to detect the effect of sex difference on plantar pressure during standing and walking.

Methods

One-hundred healthy adult volunteers (50 women and 50 men) were recruited. Ten plantar pressure sensors were implanted in a 1-mm thick insole, with a total weight of 29 g. Plantar pressure was recorded with 200 Hz during 3 s of standing and while walking 10 steps. The maximum loads during standing and walking were analyzed in each sensor, and the results were compared between different areas of the foot in the antero-posterior direction and the medio-lateral direction and between different time points. The movement of the center of pressure (COP) during walking was also evaluated. Analyses were adjusted for body mass index and gait speed.

Results

The movement of COP was constant for both sexes. In all cases, the maximum load was observed on the medial of the foot. Women had a significantly higher peak pressure on the hallux, toes, forefoot, and medial aspect of the foot compared to men while standing and walking (p < .05).

Conclusions

A newly introduced in-shoe plantar pressure sensor demonstrated a typical loading transition pattern of the foot. Furthermore, higher plantar pressure in the forefoot was detected in healthy women as compared to men during standing and walking activities.

Comparison of intraoperative soft tissue balance measurement between two tensor systems in total knee arthroplasty

BACKGROUND

Differences in measurement outcomes using different tensors in total knee arthroplasty (TKA) remain unknown. This study aimed to compare intraoperative soft tissue balance between two measurement systems in TKA.

METHODS

This study included 24 cruciate-retaining (CR) and 27 posterior-stabilized (PS) TKAs for varus-type osteoarthritis. All TKAs were performed with the measured resection technique. Intraoperative soft tissue balance was assessed with femoral component placement and patellofemoral joint reduction throughout the range of motion. Measurements were performed using the Offset Repo-Tensor (Zimmer) and Ligament Sensor Tensor (Depuy). Joint component gaps and varus/valgus ligament balance were compared statistically in CR and PS TKAs.

RESULTS

Joint component gaps with the Offset Repo-Tensor were significantly larger at 0°, 10°, 30°, and 60° of knee flexion in CR TKA and at all knee flexion angles, except 0° and 135°, in PS TKA than those with the Ligament Sensor Tensor (P < .05). Varus balance with the Offset Repo-Tensor was significantly larger at 0°, 10°, and 30° of knee flexion in CR TKA and at 10°, 30°, 60°, 90°, and 120° of knee flexion in PS TKA than that with the Ligament Sensor Tensor (P < .05).

CONCLUSION

Surgeons should consider the discrepancy in assessing intraoperative soft tissue balance depending on the tensor used. The Ligament Sensor Tensor tended to underestimate soft tissue balance in CR and PS TKAs compared with the Offset Repo-Tensor, especially in PS TKA. Thus, surgeons should know the difference in values between the offset-type tensor with consistent distraction force and a spring-loaded tensor.

The Influences of Chronicity and Meniscal Injuries on Pivot Shift in Anterior Cruciate Ligament-Deficient Knees: Quantitative Evaluation Using an Electromagnetic Measurement System

PURPOSE

To investigate the influences of time from injury to surgery and meniscal injuries on knee rotational laxity in anterior cruciate ligament (ACL)-deficient knees using the electromagnetic system retrospectively.

METHODS

Ninety-four unilateral ACL-injured patients (44 male and 50 female, mean age: 27.3 ± 11.8 years) were included. The pivot-shift test was performed before ACL reconstruction, as was a quantitative evaluation using the electromagnetic system to determine tibial acceleration. Patients were divided into 4 groups according to the chronicity: group 1, within 3 months (22 patients); group 2, between 3 and 6 months (29 patients); group 3, between 6 and 12 months (23 patients); and group 4, more than 12 months (20 patients). The presence of meniscal injuries was examined arthroscopically.

RESULTS

The tibial acceleration was significantly greater in group 4. There was a positive correlation between tibial acceleration and the time from injury to surgery (r = 0.47, P = .02). In groups 1, 2 and 3, the tibial acceleration in patients with a lateral meniscal injury was significantly greater than in patients with a medial meniscal injury and without meniscal injury. When patients with lateral meniscal injury were excluded (leaving those with medial meniscus injury or without meniscal injury), group 4 had significantly greater accelerations than other groups.

CONCLUSIONS

In ACL-deficient knees, rotational laxity increased with time and the increased rotational laxity was evident more than 1 year after injury whereas it increased with concomitant lateral meniscal injuries within 1 year after injury.

LEVEL OF EVIDENCE

Ⅳ, diagnostic study of nonconsecutive patients.