Association Between MRI Signal Intensity of the Repaired Lateral Meniscus and Residual Anterolateral Knee Laxity After ACL Reconstruction

Background

Anterolateral knee laxity (ALLx) has been linked to tears of the lateral meniscus (LM) and anterior cruciate ligament (ACL) injury.

Purpose

To investigate the longitudinal relationship between the signal intensity (SI) of the repaired LM on magnetic resonance imaging (MRI) and residual ALLx after ACL reconstruction (ACLR).

Study Design

Cohort study; Level of evidence, 3.

Methods

Included were 87 patients who underwent double-bundle ACLR and lateral meniscal repair (mean age, 23.5 years; body mass index, 23.7 kg/m2; 56 women) at a single institution between 2010 and 2019. Proton density-weighted (PDW) and T2-weighted (T2W) MRI was performed at 3, 6, and 12 months postoperatively, and the SI ratio (SIR) was calculated as (SI of the repaired LM)/(SI of the posterior cruciate ligament). At the 12-month follow-up, ALLx was evaluated using the pivot-shift test; an International Knee Documentation Committee grade ≥1 indicated residual ALLx.

Results

Overall, 12 patients (13.8%) exhibited ALLx at 12 months postoperatively. At 3 months postoperatively, the SIR on PDW images (SIR-PDW) was significantly higher in patients with ALLx versus those without ALLx (1.98 ± 0.77 vs 1.49 ± 0.52, respectively; P = .007); there was no difference in the SIR on T2W images between the groups. SIR-PDW at 3 months postoperatively was correlated negatively with patient age (r = -0.308, P = .004). When patients were stratified into a younger (≤22 years; n = 53; ALLx = 7 [13.2%]) and an older (>22 years; n = 34; ALLx = 5 [14.7%]) group, the area under the receiver operating characteristic curves (AUCs) for SIR-PDW in the younger group were statistically significant for predicting the prevalence of ALLx at all follow-up times (AUCs, 0.733-0.788) with optimal cutoff values of 2.00 at 3 months, 1.50 at 6 months, and 1.50 at 12 months. Logistic regression analysis revealed that if younger patients consistently had higher SIR-PDW values than the cutoff values, they were more likely to have residual ALLx (odds ratios, 10.24-23.57).

Conclusion

For younger patients who underwent both ACLR and lateral meniscal repair, higher MRI SI of the repaired LM was associated with a higher prevalence of residual ALLx.

Greater medial proximal tibial slope is associated with bone marrow lesions in middle-aged women with early knee osteoarthritis

BACKGROUND

Bone marrow lesion (BML) is an important magnetic resonance finding (MRI) finding that predicts knee osteoarthritis. The purpose of this study was to investigate the influence of proximal tibial morphology on BML, including the spreading root sign (SRS), in women without radiographic knee osteoarthritis (OA). It was hypothesized that varus alignment and a greater posterior tibial slopes (PTS) are associated with BML.

MATERIALS AND METHODS

A total of 359 female volunteers without knee OA who were participants in the Iwaki Health Promotion Project in 2017 or 2019 were enrolled. Participants were divided into the non-OA and early knee OA (EKOA) groups based on the Luyten's classification criteria. The presence of pathological cartilage lesions, BMLs, attritions, meniscal lesions and effusions was scored on T2-weighted fat-suppressed magnetic resonance imaging (MRI) according to the Whole-Organ MRI Scoring system. The medial proximal tibial angle (MPTA) and medial and lateral PTS (MPTS and LPTS, respectively) were measured. Regression and receiver operating characteristic (ROC) analyses were performed to reveal the relationship between BMLs and proximal tibial morphological parameters.

RESULTS

Of the 359 participants, 54 (15%) were classified as having EKOA. The prevalence of cartilage lesions, BMLs, attritions, meniscal lesions and effusions was higher in the EKOA group than in the non-OA group. The two groups had no significant difference in the proximal tibial parameters. Regression analysis revealed that age and a smaller MPTA were associated with BML in both groups. Attrition (p = 0.029) and the MPTS (p = 0.025) were positively associated with BML in the EKOA group.

CONCLUSION

The prevalence of BMLs was higher in women with EKOA and correlated with the varus and greater posterior slopes in those without radiographic knee OA.

LEVEL OF EVIDENCE

Level III, retrospective case-control study.

How much force is acting on the shoulder joint to create a Hill-Sachs Lesion or reverse Hill-Sachs Lesion?

BACKGROUND

It has not been clarified yet how much force is acting on the shoulder joint to create Hill-Sachs/reverse Hill-Sachs lesions which are commonly observed in patients with anterior or posterior shoulder instability. The purpose of this study was to determine the magnitude of force to create these bony lesions using cadaveric shoulders.

METHODS

Fourteen fresh-frozen cadaveric shoulders were used. Compression tests were performed using the universal testing machine. The specimens were randomly divided into two groups. In group A, the posterior humeral head (the bare area and articular cartilage) was first compressed against the anterior glenoid rim to simulate a Hill-Sachs lesion, followed by the anterior humeral head being compressed against the posterior glenoid rim. In group B, the same procedure was repeated in the reverse order. X-ray microcomputed tomography (microCT) was also performed.

RESULTS

The maximum compression force to create a Hill-Sachs lesion was 771 ± 214 N (mean ± SD) on the articular cartilage of the posterior humeral head, which was significantly greater than the force of 447 ± 215 N to create it on the bare area (P = 0.0086). Regarding the reverse Hill-Sachs lesions, the maximum compression force was 840 ± 198 N when it was created on the articular cartilage of the anterior humeral head, which was significantly greater than the force of 471 ± 100 N when it was created at the footprint of the subscapularis tendon (P = 0.0238). MicroCT showed multiple breakage of the trabecular bone.

CONCLUSION

A force to create a Hill-Sachs lesion or a reverse Hill-Sachs lesion was significantly greater when it was created on the humeral articular cartilage than at the non-cartilage area. Also, the force to create a reverse Hill-Sachs lesion was significantly greater than the one to create a Hill-Sachs lesion.

Concomitant Lateral Meniscus Tear is Associated with Residual Rotatory Knee Instability 1 Year after Anterior Cruciate Ligament Reconstruction: Case-cohort Study

Lateral meniscus tear (LMT) accompanied by anterior cruciate ligament (ACL) injuries has been reported to provoke rotatory instability of the affected knee joint. Unfortunately, these previous papers did not determine whether LMT-derived rotatory knee instability is residual because only preoperative or time zero data exists. This study aimed to longitudinally investigate how the prevalence of comorbid LMT is associated with residual rotatory knee instability (RKI) 1 year after ACL reconstruction (ACLR). A total of 327 patients who underwent double-bundle ACLR (average age: 23.4 years, body mass index: 23.5 kg/m2, 215 females). The patients were divided into three groups based on arthroscopy: 1) intact lateral meniscus (LM); 2) unrepaired LMT; 3) repaired LMT. At the 1-year follow-up, the pivot-shift test was performed. The prevalence of RKI, determined according to IKDC grades (grade ≥1 denoted RKI), was compared with chi-square or Fisher's exact tests. Thirty-eight patients (11.6%) had RKI; 203 subjects (62.1%) showed LMT, and 124 patients were diagnosed with an intact LM. Out of the 203 patients, 79 (38.9%) underwent LM repair. RKI was more prevalent in the LMT group than in the intact group (13.8% versus 8.1%, p = 0.117; Odds ratio: 1.499 [95%CI: 0.864 - 2.600]). In addition, the prevalence of RKI was significantly higher in the LM-repair group than in the intact-LM group (17.7% versus 8.1%, p = 0.038; Odds Ratio: 2.455 [95%CI: 1.032 - 5.842]). Medial meniscus tear (MMT) was detected in 113 patients (34.6%); RKI prevalence was not statistically different between the intact-MM group and the MMT group (12.2% versus 10.6%, p = 0.681). The current cohort study clarified that LMT comorbid with ACL injury was longitudinally associated with increased RKI prevalence 1 year after ACLR. Therefore, patients who underwent both ACLR and LM repair demonstrated a significantly higher prevalence of residual RKI.

Lower bone mineral density can be a risk for an enlarging bone marrow lesion: A longitudinal cohort study of Japanese women without radiographic knee osteoarthritis

OBJECTIVES

The aim is to elucidate the relationship between bone mineral density (BMD) at baseline and the change of bone marrow lesion (BML) during a 2-year follow-up (2YFU) period.

METHODS

Seventy-eight female participants (mean age: 54.9 ± 9.6 years) without radiographic knee osteoarthritis were eligible. Based on right-knee magnetic resonance imaging, maximum BML area (BMLa) was calculated by tracing the BML border. The change in BMLa was defined using the following formula: [2YFU] - [Baseline] = ΔBMLa. Positive ΔBMLa was defined as enlarged; negative ΔBMLa was defined as regressed. Dual-energy X-ray absorptiometry was performed to measure the BMD of distal radius. Young adult mean [YAM (%)] of the BMD was used for statistical analysis. Linear regression analysis was conducted with ΔBMLa as the dependent variable and YAM as the independent variable. Receiver operating characteristic curve and logistic regression analyses were conducted for YAM to predict the prevalence of BML enlargement or regression.

RESULTS

Twenty-six (33.3%) patients had enlarged BMLa, 12 (15.4%) participants showed regressing BMLa, and 40 (51.3%) patients remained stable. YAM was negatively associated with ΔBMLa (β: - 0.375, P = 0.046). The best predictor of BML enlargement risk was 85% (odds ratio: 8.383, P = 0.025).

CONCLUSIONS

Lower BMD could predict BML enlargement during a 2YFU period.

TiNbSn stems with gradient changes of Young's modulus and stiffness reduce stress shielding compared to the standard fit-and-fill stems

BACKGROUND

The difference between Young's moduli of the femur and the stem causes stress shielding (SS). TiNbSn (TNS) stem has a low Young's modulus and strength with gradient functional properties during the change in elastic modulus with heat treatment. The aim of this study was to investigate the inhibitory effect of TNS stems on SS and their clinical outcomes compared to conventional stems.

METHODS

This study was a clinical trial. Primary THA was performed using a TNS stem from April 2016 to September 2017 for patients in the TNS group. Unilateral THA was performed using a Ti6Al4V alloy stem from January 2007 to February 2011 for patients in the control group. The TNS and Ti6Al4V stems were matched in shape. Radiographs were obtained at the 1- and 3-year follow-ups. Two surgeons independently checked the SS grade and appearance of cortical hypertrophy (CH). The Japanese Orthopaedic Association (JOA) scores before and 1 year after surgery were assessed as clinical scores.

RESULTS

None of the patients in the TNS group had grade 3 or 4 SS. In contrast, in the control group, 24% and 40% of patients had grade 3 and 4 SS at the 1- and 3-year follow-ups, respectively. The SS grade was lower in the TNS group than in the control group at the 1- and 3-year follow-ups (p < 0.001). The frequencies of CH in both groups were no significant difference at the 1- and 3-year follow-ups. The JOA scores of the TNS group significantly improved at 1 year after surgery and were comparable to control group.

CONCLUSION

The TNS stem reduced SS at 1 and 3 years after THA compared to the proximal-engaging cementless stem, although the shapes of the stems matched. The TNS stem could reduce SS, stem loosening, and periprosthetic fractures.

TRIAL REGISTRATION

Current Controlled Trials. ISRCTN21241251. https://www.isrctn.com/search?q=21241251 . The date of registration was October 26, 2021. Retrospectively registered.

Long-term results of Chiari pelvic osteotomy on the preservation of hip function with mean follow-up of more than 30 years and its prognostic factors

BACKGROUND

Clinical outcomes of Chiari pelvic osteotomy for acetabular dysplasia, including conversion to total hip arthroplasty (THA), have not been adequately explored. The purpose of this study was to examine the long-term results and clinical outcomes of Chiari pelvic osteotomy as the primary outcome and to analyze its prognostic factors as the second outcome.

METHODS

This study was a multicenter, retrospective cohort study. Ninety-seven patients underwent Chiari pelvic osteotomy at three hospitals between March 1975 and October 1997. The long-term clinical outcomes of Chiari pelvic osteotomy, including conversion to THA and hip pain, were analyzed using the Kaplan-Meier method. In addition, the prognostic factors for conversion to THA after Chiari pelvic osteotomy were evaluated with clinical variables and radiographic parameters.

RESULTS

The study included 51 hips in 45 patients (4 men and 41 women) with long-term follow-up. The survival rates assessed by Kaplan-Meier analysis with conversion to THA as an endpoint, were 90.2% (95% confidence interval (CI) 82.0-98.4%) at 20 years and 73.5% (95% CI 61.1-86.0%) at 30 years. In contrast, the Kaplan-Meier survival rates with the Japanese Orthopaedic Association hip score for pain ≤20 as an endpoint, were 86.3% (95% CI 76.8-95.7%) at 20 years and 65.6% (95% CI 52.3-79.0%) at 30 years. Only older age at osteotomy was the significantly poor prognostic factor for conversion to THA, with a hazard ratio of 1.11/year, 95% CI 1.06 to 1.18, (p < 0.01).

CONCLUSION

Chiari pelvic osteotomy may still be a good alternative to bony reconstructive surgery for acetabular dysplasia especially in young patients. Only older age at the osteotomy was related to the poor prognosis of preserving hip function.

Two-stage revision knee arthroplasty for metallosis in a patient with rheumatoid arthritis: A case report

We report a successful case of two-stage revision total knee arthroplasty performed for treating painless metallosis after total knee arthroplasty with a metal-backed patella. A 63-year-old woman diagnosed with rheumatoid arthritis underwent left total knee arthroplasty with a metal-backed patella at 32 years of age. The patient did not have knee pain; however, knee joint swelling, a strange noise, and pigmentation were reported 4 years ago. Radiographs showed cloud and metal-line signs anteriorly and posteriorly at the femoral condyle. Therefore, a two-stage surgery was performed for infection prevention and ease of performing posterior synovectomy. The patient underwent initial synovectomy via a posterior approach, followed by anterior synovectomy and revision total knee arthroplasty. Synovectomy was performed well without perioperative infection or failure of wound healing. In cases with metallosis after total knee arthroplasty, the two-stage revision total knee arthroplasty should be considered, depending on the degree of synovial proliferation and the risk of complications.

Genome-Wide Association Study and Transcriptome of Japanese Patients with Developmental Dysplasia of the Hip Demonstrates an Association with the Ferroptosis Signaling Pathway

This study examined the association between developmental dysplasia of the hip (DDH) and disease-associated loci in a Japanese cohort. A genome-wide association study (GWAS) of 238 Japanese patients with DDH and 2044 healthy individuals was performed. As a replicate, GWAS was also conducted on the UK Biobank data with 3315 cases and matched 74,038 controls. Gene set enrichment analyses (GSEAs) of both the genetics and transcriptome of DDH were performed. Transcriptome analysis of cartilage specimens from DDH-associated osteoarthritis and femoral neck fractures was performed as a control. Most of the lead variants were very low-frequency ones in the UK, and variants in the Japanese GWAS could not be replicated with the UK GWAS. We assigned DDH-related candidate variants to 42 and 81 genes from the Japanese and UK GWASs, respectively, using functional mapping and annotation. GSEA of gene ontology, disease ontology, and canonical pathways identified the most enriched pathway to be the ferroptosis signaling pathway, both in the Japanese gene set as well as the Japanese and UK merged set. Transcriptome GSEA also identified significant downregulation of genes in the ferroptosis signaling pathway. Thus, the ferroptosis signaling pathway may be associated with the pathogenic mechanism of DDH.

Spectroscopic Quantitative Measurement of the Cartilage Surface using Arthroscopy Correlates with a Conventional Macroscopic Grading System

Purpose

To quantify the cartilage surface profile visualized during arthroscopic surgery and examine its clinical utility by comparing the results of quantitative measurements with a conventional grading system.

Methods

Fifty consecutive patients diagnosed with knee osteoarthritis and who underwent arthroscopic surgery were included in this study. A 4 K camera system was used, and the cartilage surface profile was visualized using the augmented reality imaging program. The highlighted image was displayed in 2 colors: black (the worn cartilage area) and green (the part where the cartilage thickness was maintained). The percentage of the green area was calculated using ImageJ and used as an index of cartilage degeneration. The quantitative value was statistically compared with the International Cartilage Repair Society (ICRS) grade as a conventional macroscopic evaluation.

Results

In the quantitative measurement, the median percentage of the green area was 60.7 at ICRS grades 0 and 1 (interquartile range [IQR], 67.3-51.0), 47.2 at grade 2 (IQR, 54.1-39.2), 36.5 at grade 3 (IQR, 43.2-30.4), and 34.0 at grade 4 (IQR, 38.5-29.3). There was a significant difference between the macroscopic grades, except for Grades 3 and 4. There was a significant negative correlation between macroscopic evaluation and quantitative measurement (r = -0.672, P < .001).

Conclusions

The quantitative measurement of the cartilage surface profile using the spectroscopic absorption technique was significantly correlated with the conventional macroscopic grading system and demonstrated fair to good inter-rater and intra-rater reliabilities.

Level of Evidence

Level II, diagnostic (prospective cohort study).

A modified minimally invasive surgery for thoracic pyogenic spondylitis: Percutaneous pedicle screw fixation in combination with a vertebral debridement in a separate posterolateral approach-A case report

In this report, we present a successfully treated case of intractable thoracic pyogenic spondylitis using one-step curettage/bone grafting of spinal anterior segment and less-contaminated percutaneous spinal posterior fixation via separated posterior approaches, which was not compatible with conventional spinal instruments.

Effusion detected by ultrasonography and overweight may predict the risk of knee osteoarthritis in females with early knee osteoarthritis: a retrospective analysis of Iwaki cohort data

BACKGROUND

Knee osteoarthritis (OA) has enormous medical and socioeconomic burdens, which early diagnosis and intervention can reduce. We investigated the influence of knee effusion on the progression of knee OA in patients with early knee OA.

METHODS

A total of 404 participants without radiographic knee OA were assessed from a 3-year longitudinal analysis. Participants were classified into non-OA and early knee OA groups. The effusion area (mm²) was quantified using ultrasonography. Receiver operating characteristic and logistic regression analyses were performed.

RESULTS

At the 3-year follow-up, 114 of 349 knees (32%) had progressed from non-OA and 32 of 55 knees (58%) had progressed from early knee OA to radiographic knee OA. Logistic regression analysis showed that female sex (odds ratio [OR] 3.36, 95% confidence interval [CIs] 2.98-5.42), early knee OA (OR 2.02, 95% CI 1.08-3.75), body mass index (OR 1.11, 95% CI 1.02-1.19), and effusion area (OR 1.01, 95% CI 1.01-1.02) were significantly correlated with knee OA progression. Women who were overweight (body mass index ≥ 25 kg/m²) with more severe effusion had a higher risk of OA progression (area under the curve = 0.691, OR = 6.00) compared to those not overweight (area under the curve = 0.568, OR = 1.91).

CONCLUSION

Knee effusion may be an indicator of the progression of early-stage knee OA.

Preoperative quantitative pivot shift does not correlate with in vivo kinematics following ACL reconstruction with or without lateral extraarticular tenodesis

PURPOSE

Quantitative pivot shift (QPS) testing using PIVOT technology can detect high- and low-grade rotatory knee instability following anterior cruciate ligament injury or reconstruction (ACLR). The aim of this project was to determine if preoperative QPS correlates with postoperative knee kinematics in the operative and contralateral, healthy extremity following ACLR with or without lateral extraarticular tenodesis (LET) using a highly precise in vivo analysis system. A positive correlation between preoperative QPS and postoperative tibial translation and rotation following ACLR with or without LET in the operative and healthy, contralateral extremity was hypothesized.

METHODS

Twenty patients with ACL injury and high-grade rotatory knee instability were randomized to undergo anatomic ACLR with or without LET as part of a prospective randomized trial. At 6 and 12 months postoperatively, in vivo kinematic data were collected using dynamic biplanar radiography superimposed with high-resolution computed tomography scans of patients' knees during downhill running. Total anterior-posterior (AP) tibial translation and internal-external tibial rotation were measured during the gait cycle. Spearman's rho was calculated for preoperative QPS and postoperative kinematics.

RESULTS

In the contralateral, healthy extremity, a significant positive correlation was seen between preoperative QPS and total AP tibial translation at 12 months postoperatively (r_s = 0.6, p < 0.05). There were no additional significant correlations observed between preoperative QPS and postoperative knee kinematics at 6 and 12 months postoperatively in the operative and contralateral, healthy extremity for combined isolated ACLR and ACLR with LET patients as well as isolated ACLR patients or ACLR with LET patients analyzed separately.

DISCUSSION

The main finding of this study was that there was a significant positive correlation between preoperative QPS and total AP tibial translation at 12 months postoperatively in the contralateral, healthy extremity. There were no significant correlations between preoperative QPS and postoperative in vivo kinematics at 6 and 12 months following ACLR with or without LET. This suggests that QPS as measured with PIVOT technology does correlate with healthy in vivo knee kinematics, but QPS does not correlate with in vivo kinematics following ACLR with or without LET.

Association Between Early Postoperative Graft Signal Intensity and Residual Knee Laxity After Anterior Cruciate Ligament Reconstruction

Background:

Magnetic resonance imaging (MRI) graft signal intensity is associated with graft damage after anterior cruciate ligament reconstruction (ACLR). However, little is known about the relationship between graft signal intensity and residual laxity of the reconstructed knee based on patient age.

Purpose/Hypothesis:

To evaluate the relationship between graft signal intensity and residual laxity in younger and older patients who underwent ACLR. We hypothesized that higher graft signal intensity would be associated with reduced postoperative knee stability.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 192 patients who underwent double-bundle ACLR were recruited. Proton density–weighted and T2-weighted MRI was performed at 3, 6, and 12 months after surgery, and the signal intensity ratio (SIR) of the anteromedial and posterolateral bundles was measured as the graft signal intensity reference values. At 12 months after surgery, if the KT-1000 arthrometer measurement exhibited a side-to-side difference of ≥2 mm, the patient was determined as having anterior knee laxity. Rotatory knee laxity was defined as a positive pivot shift with International Knee Documentation Committee grade ≥1. The Mann-Whitney U test was used to compare the SIR in patients with and without residual laxity. The Spearman correlation coefficient was used to evaluate the relationship between demographic parameters and the SIR. Based on receiver operating characteristic curves, the optimal SIR cutoff values to predict residual laxity were calculated, and logistic regression analysis was conducted.

Results:

Of 192 patients, 26 (13.5%) had anterior knee laxity, and 20 (10.4%) had rotatory knee laxity. The SIR was negatively correlated with age. In younger patients (<30 years; n = 135), those with residual laxity had a significantly higher SIR than those without laxity; this relationship was not significant in older patients (≥30 years; n = 57). Based on receiver operating characteristic curves and logistic regression analysis, the cutoff values that were determined for the SIR were significantly associated with a higher odds ratio of residual laxity.

Conclusion:

Graft signal intensity decreased with patient age. Patients with higher graft signal intensity in the early postoperative phase after ACLR exhibited a higher prevalence of residual laxity, particularly in younger patients.

Greater medial meniscus extrusion seen on ultrasonography indicates the risk of MRI-detected complete medial meniscus posterior root tear in a Japanese population with knee pain

To elucidate the association between medial meniscus extrusion measured on ultrasonography (MME_US) and the prevalence of medial meniscus posterior root tear detected on magnetic resonance imaging (MMPRT_MRI). We recruited 127 patients (135 knees; 90 females; mean age: 64.4 ± 8.7 years old; mean BMI: 25.5 ± 3.4 kg/m²) in this cross-sectional study. All participants had medial knee pain without a knee trauma or surgery history. Knee osteoarthritis (KOA) severity was evaluated using Kellgren-Lawrence grade (KLG) scores. Patients with KLG scores 0–1 and ≥ 2 were classified in non-radiographic (non-ROA) and radiographic KOA (ROA) groups, respectively. MME_US was measured with patients in the supine position. Based on fat-suppressed T2-weighted images, MMPRT_MRI was defined as the presence of “Ghost meniscus sign” and “Cleft/truncation sign”, indicating an abnormal high signal intensity of a completely disrupted posterior root. MME_US was compared between MMPRT+ and MMPRT– patients using a non-paired t-test. Receiver operating characteristic (ROC) curves were used to determine the optimal cut-off MME_US to predict MMPRT+. The prevalence of MMPRT+ was 31.3% (25/80 knees) and 29.1% (16/55 knees) in the non-ROA and ROA groups. The MME_US of MMPRT+ patients were significantly greater than that of MMPRT– patients in both the non-ROA (5.9 ± 1.4 mm vs. 4.4 ± 1.0 mm, P < 0.001) and ROA (7.8 ± 1.3 mm vs. 6.3 ± 1.3 mm, P < 0.001) groups. ROC curves demonstrated that 5-mm and 7-mm MME_US were the optimal cut-off values in non-ROA (adjusted odds ratio: 6.280; area under the curve [AUC]: 0.809; P < 0.001) and ROA (adjusted odds ratio: 15.003; AUC: 0.797; P = 0.001) groups. In both early non-radiographic and established radiographic KOA stages, a greater MME_US was associated with a higher MMPRT_MRI prevalence.

Bone marrow lesion severity was associated with proximal tibial inclination in early knee osteoarthritis

PURPOSE

This study aimed to investigate the effect of tibial plateau (TP) inclination and serum bone metabolic markers on bone marrow lesion (BML) in the general Japanese population with early knee osteoarthritis (EKOA).

METHODS

A total of 441 female volunteers who participated in the Iwaki Health Promotion Project in 2017 were enrolled. Participants without radiographic abnormalities were divided into normal and EKOA groups according to the Luyten's classification criteria for EKOA. The medial proximal tibial angle (MPTA), growth plate-TP angle, and growth plate-medial tibial plateau (MTP) angle were measured on standing anteroposterior radiographs of the knees. BML severity on T2-weighted fat-suppressed magnetic resonance imaging (MRI) was scored using the Whole-Organ MRI Score method. Serum levels of N-telopeptide of type I collagen, tartrate-resistant acid phosphatase-5b (TRACP-5b), bone-specific alkaline phosphatase, procollagen type I N-terminal propeptide, pentosidine, and homocysteine were assessed. Linear regression analysis was conducted to investigate the relationship between proximal tibial inclination, BML, and serum bone metabolic markers.

RESULTS

The growth plate was observed in 309 (70%) participants, and 48 (16%) participants had EKOA. The mean MPTA, growth plate-TP angle, and growth plate-MTP angle were 86.1 ± 5.9°, 3.6 ± 1.1°, and 9.9 ± 2.6°, respectively. The MPTA was negatively correlated with the growth plate-TP and growth plate-MTP angles (p = 0.006, p < 0.001). Participants with EKOA who had BML exhibited greater growth plate-MTP angle than those who did not (p = 0.018). Regression analysis revealed that BML severity was positively associated with MPTA (p = 0.036) and a bone formation marker (p = 0.045).

CONCLUSION

BML severity was positively associated with proximal tibial inclination and serum TRACP-5b level in participants with EKOA and normal knees, respectively. Assessment of proximal tibial inclination may provide insight into potential BML risk. Residual medial tibial inclination may potentially result in knee pain and symptoms in EKOA.

LEVEL OF EVIDENCE

III.

Impacts of external rotators and the ischiofemoral ligament on preventing excessive internal hip rotation: a cadaveric study

BACKGROUND

This study examined the biomechanics of preventing excessive internal hip joint rotation related to the hip flexion angle.

METHOD

An intramedullary nail with a circular plate equipped with a protractor was installed in the femur of nine normal hips. The circular plate was pulled by 3.15 Nm of force in the internal rotation direction. The external rotators were individually resected, finally cutting the ischiofemoral ligament. The cutting order of the external rotators differed on each side to individually determine the internal rotation resistance. The external rotators were resected from the piriformis to the obturator externus in the right hips and the reverse order in the left hips. Traction was performed after excising each muscle and ischiofemoral ligament. Measurements were taken at 0°, 30°, and 60° of hip flexion, and the differences from baseline were calculated.

RESULTS

For the right hip measurements, the piriformis and ischiofemoral ligament resection significantly differed at 0° of flexion (p = 0.02), each external rotator and the ischiofemoral ligament resections significantly differed at 30° of flexion (p < 0.01), and the ischiofemoral ligament and piriformis and inferior gemellus resections significantly differed at 60° of flexion (p = 0.04 and p = 0.02, respectively). In the left hips, the ischiofemoral ligament and obturator externus, inferior gemellus, and obturator internus resections significantly differed at 0° of flexion (p < 0.01, p < 0.01, and p = 0.01, respectively), as did each external rotator and the ischiofemoral ligament resections at 30° of flexion (p < 0.01).

CONCLUSION

The ischiofemoral ligament primarily restricted the internal rotation of the hip joint. The piriformis and obturator internus may restrict internal rotation at 0° and 60° of flexion.

Anterior cruciate ligament reconstruction with lateral extraarticular tenodesis better restores native knee kinematics in combined ACL and meniscal injury

PURPOSE

To determine if anterior cruciate ligament (ACL) reconstruction (ACLR) with lateral extraarticular tenodesis (LET) is beneficial for restoring knee kinematics with concomitant meniscal pathology causing rotatory knee instability.

METHODS

Twenty patients with an ACL tear were randomized to either isolated ACLR or ACLR with LET. Patients were divided into four groups based on the surgery performed and the presence of meniscal tear (MT): ACLR without MT, ACLR with MT, ACLR with LET without MT, and ACLR with LET with MT. Kinematic data normalized to the contralateral, healthy knee were collected using dynamic biplanar radiography superimposed with high-resolution computed tomography scans of patients' knees during downhill running. Anterior tibial translation (ATT) and tibial rotation (TR) as well as patient-reported outcome measures (PROMs) were analyzed at 6- and 12-months postoperatively.

RESULTS

At 6 months, ACLR with LET resulted in significantly decreased ATT at heel strike compared to ACLR (ACLR without MT: 0.3 ± 0.8 mm and ACLR with MT: 1.4 ± 3.1 mm vs. ACLR with LET without MT: - 2.5 ± 3.4 mm and ACLR with LET with MT: - 1.5 ± 1.2 mm ATT, p = 0.02). At 6 months, at toe off ACLR with LET better restored ATT to that of the contralateral, healthy knee in patients with meniscal pathology, while in patients without meniscal pathology, ACLR with LET resulted in significantly decreased ATT (1.0 ± 2.6 mm ATT vs. - 2.6 ± 1.7 mm ATT, p = 0.04). There were no significant differences in kinematics or PROMs between groups at 12 months.

CONCLUSION

For combined ACL and meniscus injury, ACLR with LET restores native knee kinematics at toe off but excessively decreases ATT at heel strike in the early post-operative period (6 months) without altering knee kinematics in the long term. Future large-scale clinical studies are needed to better understand the function of LET and ultimately improve patient outcomes.

LEVEL OF EVIDENCE

III.

Higher fasting blood glucose worsens knee symptoms in patients with radiographic knee osteoarthritis and comorbid central sensitization: an Iwaki cohort study

BACKGROUND

Although cross-sectional and cohort data suggest that higher serum blood glucose levels in patients with knee osteoarthritis (KOA) are associated with more severe knee symptoms, little is known about the longitudinal relationship between serum blood glucose and knee symptoms, particularly considering central sensitization (CS) comorbidity, which also worsens knee symptoms.

METHODS

We evaluated the longitudinal relationship between serum blood glucose and knee symptoms by dividing the cohort of patients with KOA into those with and without CS. We hypothesized that higher serum blood glucose levels would worsen knee symptoms. A total of 297 participants (mean age: 59.6 years; females: 211; average BMI: 23.7 kg/m²) were enrolled in this study. At baseline, plain radiographs of the bilateral knee joints were evaluated according to the Kellgren-Lawrence grade (KLG). All participants exhibited at least a KLG ≥ 2 in each knee. At baseline, fasting blood glucose (FBG) and Central Sensitization Inventory-9 (CSI-9) were evaluated; ≥ 10 points on the CSI-9 was defined as CS+. Knee injury and Osteoarthritis Outcome Score (KOOS) was evaluated at baseline and at 1-year follow-up; the change in KOOS (ΔKOOS) was calculated by subtracting the KOOS at baseline from that at the 1-year follow-up. Multiple linear regression analysis was conducted with ΔKOOS as the dependent variable and FBG at baseline as the independent variable, adjusted for age, sex, BMI, and CSI-9 at baseline.

RESULTS

Of the 297 subjects, 48 (16.2 %) were defined as CS+. In the CS - group, there was no association between FBG levels at baseline and ΔKOOS. In contrast, FBG at baseline was negatively associated with ΔKOOS pain (B = - 0.448; p = 0.003), ADL (B = - 0.438; p = 0.003), and sports (B = - 0.706; p = 0.007).

CONCLUSIONS

In patients with radiographic KOA and CS, higher blood glucose levels were associated with deteriorated knee symptoms during the 1-year follow-up. Healthcare providers should pay attention to controlling blood glucose, particularly in patients with KOA and concurrent CS, to mitigate their knee symptoms.

STUDY DESIGN

Retrospective cohort study (evidence level: III).

Central Sensitization and Postoperative Improvement of Quality of Life in Total Knee and Total Hip Arthroplasty: A Prospective Observational Study

Background:

While total knee arthroplasty (TKA) and total hip arthroplasty (THA) lead to excellent clinical outcomes, some patients experience residual surgical site pain and reduced satisfaction. This prospective observational study investigated the prevalence of preoperative and postoperative residual central sensitization (CS) after TKA and THA. The influence of residual CS on the improvement in quality of life (QOL) was also investigated.

Methods:

The participants were 40 patients who underwent TKA and 47 patients who underwent THA. CS was measured using the central sensitization inventory (CSI) questionnaire. Knee symptoms were evaluated using the Knee Injury and Osteoarthritis Outcome Scales (KOOS), and hip symptoms were evaluated using the Japanese Orthopedic Association Hip-disease Evaluation Questionnaires (JHEQ). General QOL was evaluated using EuroQOL (EQ-5D-5l). Regression analysis was performed to estimate factors related to low QOL after surgery.

Results:

Preoperatively, 47.5% of TKA patients and 66.0% of THA patients were CS positive (P=0.083), which reduced to 10.0% (P=0.042) and 25.5% (P=0.202), respectively, 3 months after surgery. Although the improvements in KOOS subscales and EQ-5D-5l scores in TKA patients with residual CS were significantly lower than in those without residual CS, residual CS status had no effect on JHEQ subscales and EQ-5D-5l scores in THA patients. Regression analysis indicated that EQ-5D-5l was negatively correlated with CSI in the TKA group (P=0.017). In contrast, CSI was not correlated with EQ-5D-5l in the THA group (P=0.206).

Conclusion:

Postoperative QOL improvement was achieved 3 months after THA regardless of residual CS status. In contrast, preoperative CS was negatively associated with the improvement in QOL after TKA.

Laterally shifted tibial tunnel can be the risk of residual knee laxity for double-bundle anterior cruciate ligament reconstruction

PURPOSE

To elucidate the relationship between graft tunnel position and knee laxity in the cases of double-bundle ACL reconstruction.

METHODS

Total of 132 cases were included. Femoral and tibial tunnels were evaluated by quadrant method on 3D-CT. As additional reference of tibia, the distances from medial tibial spine to the tunnel center (D_MS) and from Parsons' knob to the tunnel center (D_PK) were evaluated; %D_MS/ML and %D_PK/AP were calculated (ML and AP: mediolateral and anteroposterior width of tibial plateau). Preoperative and postoperative (1 year from surgery) stabilities were evaluated by Lachman and pivot-shift procedures. If there was ≥ 2 mm side-to-side difference, the subject was defined as having anterior knee laxity (AKL); if the pivot-shift phenomenon was observed with IKDC grade ≥ 1, there was rotatory knee laxity (RKL). Multiple logistic regression analysis was conducted with the prevalence of AKL or RKL as the dependent variable and with tunnel positions as the independent variables.

RESULTS

Overall, 21 subjects (15.9%) showed AKL, and 15 subjects (11.4%) showed RKL. Those with postoperative laxity showed higher %D_MS/ML and higher femoral position than those without laxity. Regarding posterolateral bundle, logistic regression model estimated that %D_MS/ML was associated with the prevalence of AKL (B = 0.608; p < 0.001) and RKL (B = 0.789; p < 0.001); %high-low femoral tunnel position (B =  - 0.127; p = 0.023) was associated with that of RKL.

CONCLUSION

There was the risk of residual knee laxity in ACL-reconstructed knee when tibial tunnel shifted more laterally or higher femoral tunnel was created with regard to posterolateral bundle.

LEVEL OF EVIDENCE

III.

The effect of lateral extra-articular tenodesis on in vivo cartilage contact in combined anterior cruciate ligament reconstruction

PURPOSE

Lateral extra-articular tenodesis (LET) may confer improved rotational stability after anterior cruciate ligament reconstruction (ACLR). Little is known about how LET affects in vivo cartilage contact after ACLR. The aim of this study was to investigate the effect of LET in combination with ACLR (ACLR + LET) on in vivo cartilage contact kinematics compared to isolated ACLR (ACLR) during downhill running. It was hypothesised that cartilage contact area in the lateral compartment would be larger in ACLR + LET compared with ACLR, and that the anterior-posterior (A-P) position of the contact center on the lateral tibia would be more anterior after ACLR + LET than after ACLR.

METHODS

Twenty patients were randomly assigned into ACLR + LET or ACLR during surgery (ClinicalTrials.gov:NCT02913404). At 6 months and 12 months after surgery, participants were imaged during downhill running using biplane radiography. Tibiofemoral motion was tracked using a validated registration process. Patient-specific cartilage models, obtained from 3 T MRI, were registered to track bone models and used to calculate the dynamic cartilage contact area and center of cartilage contact in both the medial and lateral tibiofemoral compartments, respectively. The side-to-side differences (SSD) were compared between groups using a Mann-Whitney U test.

RESULTS

At 6 months after surgery, the SSD in A-P cartilage contact center in ACLR + LET (3.9 ± 2.6 mm, 4.4 ± 3.1 mm) was larger than in ACLR (1.2 ± 1.6 mm, 1.5 ± 2.0 mm) at 10% and 20% of the gait cycle, respectively (p < 0.01, p < 0.05). There was no difference in the SSD in cartilage contact center at 12 months after surgery. There was no difference in SSD of cartilage contact area in the medial and lateral compartments at both 6 and 12 months after surgery. There were no adverse events during the trial.

CONCLUSION

LET in combination with ACLR may affect the cartilage contact center during downhill running in the early post-operation phase, but this effect is lost in the longer term. This suggests that healing and neuromuscular adaptation occur over time and may also indicate a dampening of the effect of LET over time. (337 /350 words) LEVEL OF EVIDENCE: Level II.

Mid-term results of a new femoral prosthesis using Ti-Nb-Sn alloy with low Young's modulus

Background

This study was performed to investigate the mid-term results of Ti-Nb-Sn (TNS) alloy stem with a low Young’s modulus.

Methods

This study was a multicenter prospective cohort study. A total of 40 primary total hip arthroplasties performed between April 2016 and September 2017 was enrolled in this study. With the unique functional gradient properties by heating treatment, the strength of the proximal portion was enhanced, while the distal portion maintained a low Young’s modulus. The surgeries were performed through the posterolateral approach using the TNS alloy stems. Radiographs were taken from immediately after surgeries until 3 years, and stress shielding and subsidence of the stems were evaluated. The incidences of the stem breakage were also assessed. Clinical assessments were performed using Japanese Orthopaedic Association (JOA) and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ) scores.

Results

Among the 40 enrolled patients, 36 patients were female and 4 were male. At 3 years after surgery, there were no radiologic signs of loosening, subsidence, or breakage of the stem. Stress shielding was observed in 26 hips (65%). Of 26 hips, 16 hips (40%) were grade 1 and 10 hips (25%) were grade 2. There was no advanced stress shielding. The JOA and JHEQ scores significantly improved compared with the preoperative scores.

Conclusion

The current study using a new TNS alloy femoral stem showed good clinical outcomes at 3-year follow-up. Radiologically, there was no loosening or subsidence of the stem. The mild stress shielding was observed in 65% of patients.

Trial registration

Current Controlled Trials ISRCTN21241251.

The date of registration was October 26, 2021.

Retrospectively registered.

The difficulty of continuing sports activities after open-wedge high tibial osteotomy in patient with medial knee osteoarthritis: a retrospective case series at 2-year-minimum follow-up

Purpose

This study aimed to investigate the rate at which patients returned to sports after open wedge high tibial osteotomy and identify the continuity of sports activity post-operatively.

Methods

Thirty-five patients (40 knees) who underwent open-wedge high tibial osteotomy (OW-HTO) in medial knee osteoarthritis were included in this study. The mean age of the patients who underwent surgery was 55.1 ± 10.7 years, and the mean follow-up period was 41.0 ± 24.7 months. Clinical results and radiographic parameters calculated in standing whole-leg radiographs preoperatively, post-operatively, and at the final follow-up were evaluated.

Results

Thirty-one patients (88.6%) were able to return to preoperative sports activity; however, only 14 patients (40.0%) completely returned to preoperative sports activity levels. Of the 31 patients who returned to sports activity, 10 patients (32.3%) maintained post-operative sporting activity levels at the final follow-up. In radiographic parameters, the weight-bearing line ratio was considered loss of correction in the post-operative period leading to the final follow-up. Patients who completely returned to sports and maintained sporting activity levels at the final follow-up had significantly higher the Knee Injury and Osteoarthritis Outcome Score pain subscale values and lower visual analogue scale of knee pain at pre-surgery and final follow-up than other patients, including those who partially returned to sports.

Conclusions

The proportion of patients who returned to sports after OW-HTO and were able to participate in competitions at the same activity level as before surgery was low and insufficient.

Level of evidence

Retrospective case series, IV

Association Between Central Sensitization and Increasing Prevalence of Nocturnal Knee Pain in the General Population with Osteoarthritis from the Iwaki Cohort Study

Purpose

Knee pain is associated with osteoarthritis (OA) and increases during this condition; however, its correlation with central sensitization (CS) in arthritis patients requires greater understanding. The present cross-sectional cohort study to explore the prevalence of knee OA, nocturnal knee pain and disability in general population and to examine the association of CS with sleep quality in Japanese general population.

Patients and Methods

From among 1056 community-dowelling volunteers, 942 were enrolled as participants in this study. Bilateral weight-bearing anterior-posterior knee radiographs were classified by the Kellgren-Lawrence grade. Nocturnal knee pain and disability were assessed with self-reported questionnaires. Using the CS inventory with nine items (CSI-9), CS was defined as 10 points or higher. Sleep quality was scored using the Pittsburgh Sleep Quality Index (PSQI). Linear regression analysis, adjusted by age, sex, body mass index, Kellgren-Lawrence grade, nocturnal knee pain, and lifestyle habits, was performed to investigate the association of CS with PSQI.

Results

The prevalence of OA, nocturnal knee pain, and disability was 37.9%, 7.6%, and 6.2%, respectively. The mean CSI-9 score was 4.9 ± 4.4, with a CS prevalence of 14.0%. The mean PSQI score was 3.9 ± 2.4, which was correlated with the CSI-9 value. CS was not correlated with OA severity; however, nocturnal knee pain prevalence increased from 13.3% to 25.5% in knee OA patients with CS. The CSI-9 value correlated with PSQI total score and subscales.

Conclusion

Knee OA severity correlated with nocturnal pain and disability; however, its association with CS was unproven. The combined effect of knee OA and CS elevated nocturnal pain and disability, resulting in diminished sleep quality.

Lateral Extra-articular Tenodesis Contributes Little to Change In Vivo Kinematics After Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial

BACKGROUND

Lateral extra-articular tenodesis (LET) in combination with anterior cruciate ligament (ACL) reconstruction (ACLR) has been proposed to improve residual rotatory knee instability in patients having ACL deficiency.

PURPOSE/HYPOTHESIS

The purpose was to compare the effects of isolated ACLR (iACLR) versus LET in combination with ACLR (ACLR+LET) on in vivo kinematics during downhill running. It was hypothesized that ACLR+LET would reduce the internal rotation of the reconstructed knee in comparison with iACLR.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 18 patients with ACL deficiency were included. All participants were randomly assigned to receive ACLR+ LET or iACLR during surgery. Six months and 12 months after surgery, knee joint motion during downhill running was measured using dynamic biplane radiography and a validated registration process that matched patient-specific 3-dimensional bone models to synchronized biplane radiographs. Anterior tibial translation (ATT; positive value means "anterior translation") and tibial rotation (TR) relative to the femur were calculated for both knees. The side-to-side differences (SSDs) in kinematics were also calculated (operated knee-contralateral healthy knee). The SSD value was compared between ACLR+LET and iACLR groups using a Mann-Whitney U test.

RESULTS

At 6 months after surgery, the SSD of ATT in patients who had undergone ACLR+LET (-1.9 ± 2.0 mm) was significantly greater than that in patients who had undergone iACLR (0.9 ± 2.3 mm) at 0% of the gait cycle (foot strike) (P = .031). There was no difference in ATT 12 months after surgery. Regarding TR, there were no differences between ACLR+LET and iACLR at either 6 months (P value range, .161-.605) or 12 months (P value range, .083-.279) after surgery.

CONCLUSION

LET in combination with ACLR significantly reduced ATT at the instant of foot strike during downhill running at 6 months after surgery. However, this effect was not significant at 12 months after surgery. The addition of LET to ACLR had no effect on TR at both 6 and 12 months after surgery.

CLINICAL RELEVANCE

LET in combination with ACLR may stabilize sagittal knee motion during downhill running in the early postoperation phase, but according to this study, it has no effect on 12-month in vivo kinematics.

REGISTRATION

NCT02913404 (ClinicalTrials.gov identifier).

Usefulness of serum hyaluronic acid levels as a predictor of incidence of hand osteoarthritis analyzed by longitudinal analysis from the Iwaki cohort

The factors predicting hand osteoarthritis (HOA) in patients remain unknown. We aimed to investigate the usefulness of serum hyaluronic acid (sHA) levels in predicting HOA progression from a 6-year longitudinal epidemiological study. A total of 417 participants in the Iwaki cohort were followed-up over 6 years. Hand and knee radiographs taken at baseline and follow-up were scored according to Kellgren–Lawrence grades and Kallman score. Participants were classified into the HOA group and the non-HOA group. sHA levels at baseline were determined by ELISA. Correlations between sHA levels, the number of involved joints, and Kallman score were estimated. Factors related to the incidence or progression of HOA over 6 years were analyzed. The prevalence of HOA was 19.9% at baseline, and 3.6 ± 2.1 joints were involved. sHA levels in the HOA group at baseline were significantly higher than in the non-HOA group (p < 0.001) and correlated with the number of involved joints (r = 0.399, p < 0.001) and Kallman score (r = 0.540, p < 0.001). The incidence rate was 14.5%, and the progression rate was 46.1% over 6 years. Higher sHA levels at baseline were the risk factor of HOA incidence. Thus, sHA levels predicted the incidence of HOA over 6 years.

The effect of low back pain and neck-shoulder stiffness on health-related quality of life: a cross-sectional population-based study

BACKGROUND

This cross-sectional study sought to determine the neck-shoulder stiffness/low back pain (NSS/LBP) comorbidity rate in a Japanese community population and to compare the quality of life (QOL) in individuals with comorbid NSS/LBP, asymptomatic individuals, and those with symptoms of NSS or LBP alone.

METHODS

The sample included 1122 subjects (426 men; 696 women) with NSS and LBP symptoms in the previous 3 months, and were grouped according to NSS, LBP, comorbid NSS and LBP symptoms (Comorbid), or no symptoms (NP). They completed the MOS 36-Item Short-Form Health Survey (SF-36). Health QOL was evaluated by the eight domain scores and the Physical Component Summary (PCS) and Mental Component Summary (MCS) scores after adjusting for age. The primary outcome was to examine the association between NSS/LBP, NSS, or LBP and bodily pain of the eight domains of SF-36. Secondary outcome was to compare health-related QOL among the four groups.

RESULTS

Morbidity was 45.6% for NSS and 51.9% for LBP. Comorbidity affected 23% of men and 33% of women. Comorbid NSS/LBP, NSS, and LBP alone were independently associated with bodily pain after adjusting for potential confounders. Men who exhibited comorbidity had significantly lower MCS scores than asymptomatic men. Women who exhibited comorbidity and LBP had significantly lower MCS scores than those with no symptoms or NSS alone. Women who exhibited comorbidity had significantly lower MCS scores than those with no symptoms or LBP alone.

CONCLUSIONS

Comorbidity of the two diseases is prevalent in 23% of the men and 33% of women in the Japanese sample. Although NSS, LBP, and comorbidity were independently associated with QOL in terms of pain, QOL was worse in individuals who exhibited comorbidity than in those without symptoms or with NSS alone.

Mid-term result of acetabular reconstruction using a Kerboull-type acetabular reinforcement device with hydroxyapatite impaction

The aim of this study is to investigate the mid-term results of 29 hips in 26 patients who underwent acetabular reconstruction using a Kerboull-type acetabular reinforcement device and impaction with hydroxyapatite (HA) granules. The acetabular bone defects were AAOS type II for six hips and type III for 23 hips. The mean Merle d’Aubigné clinical scores were significantly improved after operation. Six hips developed implant migration and breakage, and five of six hips were revised after an average of 5.5 (range 2.0–8.8) years. All hips with thickness of the grafted HA less than 10 mm were stable. As the HA became thicker, the failure rate were significantly increased. The Kaplan–Meier survival rates at 10 years were 73.2%, with 100% and 67.0% for AAOS type II and III defect respectively as the end point was failure condition. Reconstruction using a Kerboull-type acetabular reinforcement device and impaction with HA granules was an alternative method in the absence of adequate allografts.

Functional analysis of a novel lytic polysaccharide monooxygenase from Streptomyces griseus on cellulose and chitin

Lytic polysaccharide monooxygenases (LPMOs) are enzymes that degrade polysaccharides with an oxidative mechanism and contributed to the efficiency in biomass degradation by glycoside hydrolases (GHs). In this study, the substrate and reaction specificity of SgLPMO10A that was an auxiliary activity family 10 (AA10) enzyme with a carbohydrate binding module family 2 (CBM2) domain from Streptomyces griseus, was analyzed. This enzyme produced oxidized cello-oligosaccharides from cellulose and boosted cellulose degradation by cellulases. Detailed study of the AA10 and CBM2 domains revealed that the binding ability of SgLPMO10A depended on CBM2 and that only the AA10 domain functions more effectively in the presence of a certain amount of substrates.

Detection of synovitis in early knee osteoarthritis by MRI and serum biomarkers in Japanese general population

To investigate synovitis' influence on early knee osteoarthritis (EKOA) by serum biomarkers and magnetic resonance imaging (MRI) findings in Japanese women. We enrolled 255 women aged 30-70 without radiographic abnormalities (Kellgren-Lawrence grade ≥ 2). Knee injury, OA outcome scores (KOOS), clinical examinations, and standing radiograph were used for classification criteria of EKOA. Participants were classified into normal knee group and EKOA group. All participants underwent MRIs of their right knee. The amount of effusion-synovitis volume was quantified. We compared serum matrix metalloproteinases-3 levels (MMP-3), high-sensitivity C-reactive protein, interleukin-6, and adiponectin between the groups. The relationship between synovitis and EOKA was investigated using multiple linear regression. Fifty-four participants (21%) were classified as EKOA. Serum MMP-3 concentration and effusion-synovitis volume were higher in patients with EKOA (p = 0.025 and p = 0.001, respectively). Effusion-synovitis volume negatively correlated with all KOOS subscales and positively correlated with serum MMP-3 concentration. Serum MMP-3 concentration was associated with effusion-synovitis volume β = 0.60, p < 0.001). There was mildly active but definitive synovitis in EKOA. This was an observational study so that no conclusions can be drawn regarding cause-effect for synovitis and symptoms. Future studies should conduct follow-up of participants with synovitis to assess the progression of knee OA.

Predicting radiological vertebral fractures with a combined physical function and body composition scoring system

The objective of this study was to investigate the incidence of vertebral fractures (VFx) and the value of physical function (PF) and body composition (BC) for predicting VFx in a Japanese population. This study included 307 subjects (113 men, 194 women) at least 40 years of age who were assessed at community health check-ups in 2008 and 2016. PF was assessed by grip strength and by single-leg stance, timed up-and-go, and 30-s chair stand tests, each scored from 0 to 3 for a possible total of 12 points (higher scores reflect lower function). BC was scored on bioelectrical impedance measurements of trunk and appendage muscle volume, with 6 possible points. We diagnosed radiological VFx semiquantitatively on lateral views of the lumbar spine, and measured bone mineral status by quantitative ultrasound (QUS) of the calcaneus. We conducted logistic regression analysis with VFx as the dependent variable and age, sex, BMI, QUS, PF score, and BC score as independent variables. In 8 years, 36 participants (12%) sustained new VFx. After correcting for age, sex, BMI, and QUS, the odds of VFx increased with a PF score ≥ 8 (OR 5.6; 95% CI 1.21-25.90; P = 0.028) and increased further with a PF + BC score ≥ 9 (OR 8.1; 95% CI 1.80-36.00; P < 0.01). Both PF and BC are important for predicting fragility fractures. The scoring system used here may reflect small differences better than categorical (single cutoff) definitions of poor function.

The Complex Relationship Between In Vivo ACL Elongation and Knee Kinematics During Walking and Running

In vivo anterior cruciate ligament (ACL) bundle (anteromedial bundle [AMB] and posterolateral bundle [PLB]) relative elongation during walking and running remain unknown. In this study, we aimed to investigate in vivo ACL relative elongation over the full gait cycle during walking and running. Ten healthy volunteers walked and ran at a self-selected pace on an instrumented treadmill while biplane radiographs of the knee were acquired at 100 Hz (walking) and 150 Hz (running). Tibiofemoral kinematics were determined using a validated model-based tracking process. The boundaries of ACL insertions were identified using high-resolution magnetic resonance imaging (MRI). The AMB and PLB centroid-to-centroid distances were calculated from the tracked bone motions, and these bundle lengths were normalized to their respective lengths on MRI to calculate relative elongation. Maximum AMB relative elongation during running (6.7 ± 2.1%) was significantly greater than walking (5.0 ± 1.7%, p = 0.043), whereas the maximum PLB relative elongation during running (1.1 ± 2.1%) was significantly smaller than walking (3.4 ± 2.3%, p = 0.014). During running, the maximum AMB relative elongation was significantly greater than the maximum PLB relative elongation (p < 0.001). ACL relative elongations were correlated with tibiofemoral six degree-of-freedom kinematics. The AMB and PLB demonstrate similar elongation patterns but different amounts of relative elongation during walking and running. The complex relationship observed between ACL relative elongation and knee kinematics indicates that ACL relative elongation is impacted by tibiofemoral kinematic parameters in addition to flexion/extension. These findings suggest that ACL strain is region-specific during walking and running. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1920-1928, 2019.

Meniscal tear morphology independently affects pain relief following arthroscopic partial meniscectomy in middle-aged patients

PURPOSE

To analyze the influence of meniscal tear pattern on clinical outcomes following arthroscopic partial meniscectomy in middle-aged patients with medial meniscal tears.

METHODS

A total of 123 patients (130 knees) aged ≥ 50 years who underwent arthroscopic partial meniscectomy for medial meniscal tears were evaluated. Inclusion criteria were none to moderate medial knee osteoarthritis [Kellgren-Lawrence (KL) grade ≤ 3] and a minimum of 2-year follow-up (median 4.6 years; range 2.1-8.0 years). Meniscal tears observed during arthroscopic examination were classified into six types: radial tear of the middle segment, posterior root tear, horizontal tear of the posterior segment, flap tear, minor tear, and complex tear. Postoperative outcomes were classified into effective (group 1) and non-effective (group 2) according to the pain relief administered 1 month postoperatively and at the final follow-up. Demographic variables, KL grade, type of meniscal tear, and postoperative follow-up period were evaluated.

RESULTS

Forty knees (38%) were classified into group 1. Of the six types of tears, radial tear of the middle segment [odds ratio (OR) 4.1, 95% confidence interval (CI) 1.1-20.9] and flap tear (OR 12.9, 95% CI 1.8-140.7) were significant predictors of good outcome on multivariate logistic regression analysis.

CONCLUSIONS

In middle-aged patients with medial meniscal tears, radial tear of the middle segment was independently associated with less pain following arthroscopic meniscectomy. Arthroscopic partial meniscectomy may be indicated in patients with radial tear if conservative treatment fails.

LEVEL OF EVIDENCE

Case-control study, Level III.

Symptomatic bone marrow lesions induced by reduced bone mineral density in middle-aged women: a cross-sectional Japanese population study

BACKGROUND

The etiology of bone marrow lesions (BMLs) without knee osteoarthritis (KOA) and their association with bone fragility are unclear. We aimed to investigate the association between BMLs, bone mineral density (BMD), and bone markers in women without radiographic evidence of KOA.

METHODS

This single-center cross-sectional study in a Japanese population included 266 women without radiographic evidence of KOA, which was defined as a Kellgren-Lawrence grade < 2. All participants underwent coronal and sagittal T2-weighted fat-suppressed magnetic resonance imaging of their right knee. BML severity was scored according to the Whole-Organ MRI Scoring method. BMD was measured by dual-energy X-ray absorptiometry of the forearm. Levels of bone markers (bone-alkaline phosphatase [BAP], type I procollagen N-terminal propeptide [PINP], cross-linked N-telopeptide of type I collagen [NTx], and tartrate-resistant acid phosphatase-5b [TRACP-5b]), pentosidine, and homocysteine were assessed in the serum. Knee symptoms were evaluated on the basis of the Knee injury and Osteoarthritis and Outcome Score (KOOS). Participants were divided into symptomatic knee and asymptomatic knee groups on the basis of their KOOS according to the classification criteria for early KOA. Multiple linear regression analysis was performed to evaluate the relationship between BMLs, BMD, and bone markers.

RESULTS

The prevalence of BML was 35.3%. Age and some bone marker levels (BAP, PINP, NTx, and TRACP-5b) were higher, and all KOOS subscale scores and BMD were lower in participants with BMLs than in those without BMLs. On multiple linear regression analysis, BMD was negatively associated with BMLs (p = 0.014) in participants with symptomatic knees. There was no such association in participants with asymptomatic knees (p = 0.918). Among the bone markers, BAP (p = 0.006) and PINP (p = 0.043) were positively associated with BMLs in participants with symptomatic knees, while BAP (p = 0.038) and TRACP-5b (p = 0.011) were positively associated with BMLs in participants with asymptomatic knees.

CONCLUSIONS

In symptomatic Japanese women without radiographic evidence of KOA, BMD is negatively associated and some bone markers are positively associated with BMLs after adjustment for age and BMI. Thus, maintaining systemic bone metabolism could contribute to BML prevention in patients with pre-radiographic KOA.

Associations between cervical disc degeneration and muscle strength in a cross-sectional population-based study

The physical and biochemical factors related to cervical disc degeneration (CDD), which is involved in several spinal disorders, remain uncertain. We investigated associations between CDD and muscle strength in a general Japanese population. We used mid-sagittal-plane MRIs to assess CDD in 344 subjects recruited from participants in our community health-check project, and measured body mass index (BMI), skeletal muscle index (SMI), and muscle strength in the neck, trunk, hands, and legs. CDD was scored based on the prevalence and severity of intravertebral disc degeneration. Spearman correlation coefficients were used to evaluate whether the SMI or muscle-strength values were correlated with the disc degenerative score. Stepwise multiple linear regression analyses were then conducted with the CDD score as the dependent variable, and age, sex, BMI, and muscle strength as independent variables, for each gender. These analyses used the muscle-strength parameters that were found to be correlated with the CDD scores in the single correlation analyses. The CDD scores were similar in men and women. Men had significantly more muscle strength in the neck, trunk, hands, and legs. There was a significant negative corelation between the CDD score and the trunk strength in both sexes, handgrip in men, and leg strength in women in the single-variable correlation analysis. Including age and the limb- or trunk-muscle strength comprehensively, multiple linear regression analyses showed that age was the strongest factor that was independently associated with CDD in both sexes, and that the effects were attenuated by limb and trunk muscle strength.

Greater Laxity in the Anterior Cruciate Ligament-Injured Knee Carries a Higher Risk of Postreconstruction Pivot Shift: Intraoperative Measurements With a Navigation System

BACKGROUND

The presence of pivot shift after anterior cruciate ligament (ACL) reconstruction is correlated with worse clinical outcomes. An orthopaedic navigation system is a useful tool for quantifying laxity in the ACL-deficient knee.

PURPOSE

To investigate the relationship between preoperative knee laxity measured by a navigation system and postoperative pivot shift (PPS) after ACL reconstruction.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

One hundred patients who underwent primary ACL reconstruction (62 hamstring tendon grafts, 38 patellar tendon grafts) were grouped according to the presence or absence of pivot shift at the 2-year follow-up, and the groups were compared retrospectively. Before surgery, knee laxity was assessed with a navigation system to quantify posterior tibial reduction (PTR) during pivot-shift tests and anterior tibial translation (ATT) during Lachman tests. PTR and ATT cutoff values were determined by receiver operator characteristic (ROC) analysis.

RESULTS

Preoperative PTR and ATT were significantly larger for patients with PPS (PPS-positive group) than those without (PPS-negative group). In the ROC analysis, the PTR had an area under the curve of 0.871 (95% CI, 0.763-0.979; P < .0001) for predicting a PPS; this was larger than that obtained for the ATT, which had an area under the curve of 0.825 (95% CI, 0.705-0.946; P = .001). Because the ROC curve of the ATT had 2 peaks, the ATT alone was not a suitable predictor for PPS. Based on the ROC curve, the optimal PTR cutoff value was 7 mm, with 88.9% sensitivity and 71.4% specificity for PPS (adjusted odds ratio = 19.7; 95% CI, 2.1-187.9; P = .009). Setting the cutoff value as a combination of the PTR (≧7 mm) and ATT (≧12 mm) improved the specificity (88.9% sensitivity and 84.6% specificity; adjusted odds ratio = 149.8; 95% CI, 5.9-3822.7; P = .002) over that with the PTR alone.

CONCLUSION

ACL injuries in knees with a large PTR had a higher risk of PPS. When reconstructing the ACL in a knee with a high degree of laxity, surgeons may need to adopt strategies to prevent PPS.

Biomechanical analysis of supra-acetabular insufficiency fracture using finite element analysis

BACKGROUND

Supra-acetabular insufficiency fractures (SAIFs) occur in the upper acetabulum and are rare compared with insufficiency sacral, femoral head, or ischial fractures. However, SAIFs are known to occur in low grade trauma, and the underlying mechanism is still remained unclear.

METHODS

We performed biomechanical analysis using finite element analysis to clarify the mechanisms underlying the development of SAIFs. Patient-specific models and bone mineral density (BMD) were derived from pelvic computed tomography data from two patients with SAIF (unaffected side) and two healthy young adults. The bone was assumed to be an isotropic, linearly elastic body. We assigned Young's modulus of each element to the pelvis based on the BMD, and reported the relationships for BMD-modulus. Clinically relevant loading conditions-walking and climbing stairs-were applied to the models. We compared the region of failure risk in each acetabulum using a maximum principal strain criterion.

RESULTS

The average supra-acetabular BMD was less than that of the hemi-pelvis and femoral head, but was higher than that of the femoral neck and greater trochanter. Greater minimum principal strain was concentrated in the supra-acetabular portion in both the SAIF and healthy models. In the SAIF models, the higher region of the failure risk matched the fracture site on the acetabulum.

CONCLUSIONS

Relative fragility causes compressive strain to concentrate in the upper acetabulum when walking and climbing stairs. When presented with a patient complaining of hip pain without apparent trauma or abnormal X-ray findings, physicians should consider the possibility of SAIF and perform magnetic resonance imaging for the diagnosis of SAIF.

Serum pepsinogen levels indicate the requirement of upper gastrointestinal endoscopy among Group A subjects of ABC classification: a multicenter study

BACKGROUND

ABC classification has been used to assess the risk for gastric cancer. The current problem of ABC classification is that Group A contains individuals with current and past H. pylori infection. The aims of this study were to assesse the proportion of current and past infection in Group A and to establish a criteria for the identification of subjects with past infection from Group A subjects with negative results of urea breath test (UBT) and/or stool antigen test.

METHODS

201 subjects classified into Group A received UBT and/or stool antigen test, and also subsequent upper gastrointestinal endoscopy. The subjects were classified by the status of H. pylori infection defined by endoscopic findings. Levels of pepsinogen (PG) I, PG II and PG I/II ratio were compared between the groups, and receiver operating characteristic curves were constructed to extract the corresponding cutoff values.

RESULTS

22 subjects were tested positive by UBT and/or stool antigen test. Endoscopic images of 157 out of 179 subjects were studied. 15 of the subjects were regarded to have past H. pylori infection. The optimal cut-off value of PG I and PG I/II ratio for the determination of past H. pylori infection were ≤ 31.2 ng/mL and ≤ 4.6, respectively.

CONCLUSIONS

Approximately 20% of Group A subjects have current or past H. pylori infection. Addition of UBT and/or stool antigen test can identify current but not past infection. Serum PG levels would be useful to identify subjects with past H. pylori infection.

A study of the factors associated with cervical spinal disc degeneration, with a focus on bone metabolism and amino acids, in the Japanese population: a cross sectional study

Background

The physical and biochemical factors responsible for cervical disc degeneration, and resulting in various spinal disorders, remain unclear. This study aimed to evaluate the correlation between cervical spinal canal stenosis and degeneration of intervertebral discs, and to analyze the factors related to disc degeneration in the Japanese population.

Methods

Three hundred and forty-four Japanese general residents underwent investigations, including magnetic resonance imaging of the cervical spine, in our health check project. We measured anteroposterior diameters at the levels of the cervical spinal disc in mid sagittal plane magnetic resonance imaging and evaluated disc degeneration. Spearman correlation coefficient was used to evaluate whether the diameters were correlated with disc degenerative scores. Stepwise multiple linear regression analysis was conducted with the score of disc degeneration as the dependent variable; and age, physical measurement values, bone mineral density of the forearm, and the value of serum bone metabolic markers and amino acids as the independent variables for each sex.

Results

As the age increased, the anteroposterior diameters decreased in both sexes. The minimum anteroposterior diameters were correlated with the disc degenerative scores (Spearman r = − 0.59, p < 0.001 in men, Spearman r = − 0.53, p < 0.001 in women). In multiple linear regression analysis, age, cross-linked N-telopeptide of type 1 collagen and isoleucine were significantly correlated with the cervical disc degenerative score in men (R² = 0.47), and age and lysine were significantly correlated with the degenerative score in women (R² = 0.50).

Conclusion

The factors responsible for cervical disc degeneration differed between men and women. Whether modifying these significant factors is possible, or whether this intervention would contribute to prevention of disc degeneration requires future studies.

Microscopic Investigation into the Electric Field Effect on Proximity-Induced Magnetism in Pt

Electric field effects on magnetism in metals have attracted widespread attention, but the microscopic mechanism is still controversial. We experimentally show the relevancy between the electric field effect on magnetism and on the electronic structure in Pt in a ferromagnetic state using element-specific measurements: x-ray magnetic circular dichroism (XMCD) and x-ray absorption spectroscopy (XAS). Electric fields are applied to the surface of ultrathin metallic Pt, in which a magnetic moment is induced by the ferromagnetic proximity effect resulting from a Co underlayer. XMCD and XAS measurements performed under the application of electric fields reveal that both the spin and orbital magnetic moments of Pt atoms are electrically modulated, which can be explained not only by the electric-field-induced shift of the Fermi level but also by the change in the orbital hybridizations.

Infection of Helicobacter pylori and Atrophic Gastritis Influence Lactobacillus in Gut Microbiota in a Japanese Population

Background

Suppression of gastric acid by proton pump inhibitors is associated with the increase of Lactobacillus in human gut microbiota. Gastric acid secretion is also suppressed by Helicobacter pylori infection and following atrophic gastritis. However, few studies have examined the association between H. pylori infection and Lactobacillus species in gut microbiota particularly in Japan.

Methods

A total of 1,123 adult subjects who participated in a health survey in Hirosaki City were studied. Infection of H. pylori was defined by both serum antibody and stool antigen test. The presence and the severity of atrophic gastritis were defined by the serum level of serum pepsinogens. Using 16S ribosomal RNA amplification from fecal samples, the relative abundance of Lactobacillus was calculated, and the composition ratio of each Lactobacillus species was surveyed.

Results

The relative abundance of the Lactobacillus in H. pylori-infected subjects with severe atrophic gastritis was higher comparing with those in subjects with mild atrophic gastritis and without atrophic gastritis (0.591 vs 0.068% and 0.033%, respectively; p < 0.001) and also that of non-infected subjects (0.033%; p < 0.001). In H. pylori non-infected subjects, both gender and age were not associated with the relative abundance of Lactobacillus in fecal samples. The proportion of Lactobacillus salivarius was high in H. pylori-infected subjects while that of Lactobacillus acidophilus was high in non-infected subjects.

Conclusion

Lactobacillus in human gut microbiota could be influenced by H. pylori infection and severity of atrophic gastritis in Japanese subjects.

Associations between neck symptoms and LDL cholesterol in a cross-sectional population-based study

BACKGROUND

Studies have reported associations between neck pain and degenerative changes in the cervical spine in women, and between neck pain and obesity or metabolic syndrome. The present study investigated associations between neck pain or stiffness and lipid profiles in subjects recruited from the general population of a Japanese community.

METHODS

The 1122 volunteers who participated in this study included 426 men (age 52.6 ± 15.5 years; body mass index 23.6 ± 3.2) and 696 women (age 55.3 ± 15.3 years; body mass index 22.2 ± 3.4). Each subject filled out a questionnaire about any neck pain or neck-shoulder stiffness experienced in the previous 3 months. We recorded the following laboratory results related to metabolic factors, including lipid profiles: total cholesterol, LDL and HDL cholesterol, triglycerides, free fatty acids, glucose, and hemoglobin A1c. We conducted logistic and linear regression analyses using the prevalence of neck pain or neck-shoulder stiffness as the dependent variable and age, sex, body mass index, and laboratory data as independent variables.

RESULTS

There was no significant difference in the prevalence of neck pain between men (20.5%) and women (21.5%). However, the prevalence of neck and shoulder stiffness was significantly higher in women (60.3%) than in men (38.0%; P < 0.05). Logistic and linear regression analyses showed a significant negative correlation between the prevalence of neck pain and LDL cholesterol (odds ratio [OR], 0.958; 95% CI, 0.921-0.997), and between the prevalence of neck-shoulder stiffness and age (OR, 1.025; 95% CI, 1.013-1.038) and gender (OR, 0.362; 95% CI, 0.25-0.494).

CONCLUSION

LDL cholesterol was correlated with neck pain in this cross-sectional population-based study.

Age-related reduction of trunk muscle torque and prevalence of trunk sarcopenia in community-dwelling elderly: Validity of a portable trunk muscle torque measurement instrument and its application to a large sample cohort study

Trunk muscle weakness and imbalance are risk factors for postural instability, low back pain, and poor postoperative outcomes. The association between trunk muscle strength and aging is poorly understood, and establishing normal reference values is difficult. We aimed to establish the validity of a novel portable trunk muscle torque measurement instrument (PTMI). We then estimated reference data for healthy young adults and elucidated age-related weakness in trunk muscle strength. Twenty-four university students were enrolled to validate values for PTMI, and 816 volunteers from the general population who were recruited to the Iwaki Health Promotion Project were included to estimate reference data for trunk muscle strength. Trunk flexion and extension torque were measured with PTMI and KinCom, and interclass correlation coefficients (ICC) were estimated to evaluate the reliability of PTMI values. Furthermore, from the young adult reference, the age-related reduction in trunk muscle torque and the prevalence of sarcopenia among age-sex groups were estimated. The ICC in flexion and extension torque were 0.807 (p<0.001) and 0.789 (p<0.001), respectively. The prevalence of sarcopenia increased with age, and the prevalence due to flexion torque was double that of extension torque. Flexion torque decreased significantly after 60 years of age, and extension torque decreased after 70 years of age. In males over age 80, trunk muscle torque decreased to 49.1% in flexion and 63.5% in extension. In females over age 80, trunk muscle torque decreased to 60.7% in flexion and 68.4% in extension. The validity of PTMI was confirmed by correlation with KinCom. PTMI produced reference data for healthy young adults, and demonstrated age-related reduction in trunk muscle torque. Trunk sarcopenia progressed with aging, and the loss of flexion torque began earlier than extension torque. At age 80, trunk muscle torque had decreased 60% compared with healthy young adults.

Abstract P5-23-05: Prognostic value of PD-L1 expression in male breast cancer

Background

Growing evidence have shown promise for targeting programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) signaling in several tumors. In female breast cancer, PD-L1 expression has been correlated with poor clinical outcome. However, whether PD-L1 has any indication for prognosis in male breast cancer (MBC) patients remains unknown. The purpose of this study was to examine the expression levels of PD-L1 in MBC and to identify the relationship between PD-L1 expression and patient survival.

Methods

We retrospectively identified 110 male breast cancer patients diagnosed between 2000 and 2013 at Salah Azaïz Cancer Institute. PD-L1 expression was evaluated by immunohistochemistry (IHC) using CD274 antibody. Specimens were scored as IHC low or high, when &lt; 5% or ≥ 5% of cells were PD-L1 positive, respectively. The association between expression of PD-L1 and survival was investigated using Kaplan-Meier survival and COX proportional hazard regression analyses.

Results

Median follow up was 12.5 months [range 1-132 months]. High expression of PD-L1 was observed in 64.5% of MBC samples (71/110). PD-L1 expression was significantly associated with advanced clinical stage (p=0.012), higher histological grade (p=0.014), higher Ki67 expression (p=0.023) and hormone-receptor negative status (p=0.024). Patients with high PD-L1 expression had significantly shorter overall survival (OS) than patients with low expression (p=0.002, hazard ratio (HR) =5 [2.624–10.642]). Multivariate analysis identified PD-L1 as an independent prognostic factor for OS (p&lt;0.001, HR = 0.775 [0.680–0.870]).

Conclusion

Our results indicate that high PD-L1 expression may be a prognostic indicator for reduced OS. Thus, PD-L1 expression is a promising novel biomarker with prognostic significance in MBC and may suggest a potential therapeutic target of anti-PD-L1 antibody therapy in MBC patients.

Citation Format: Abdeljaoued S, Bettaieb I, Adouni O, Goucha A, Chiba D, Bouzaiene H, Ben Hassouna J, Boussen H, Rahal K, Gamoudi A. Prognostic value of PD-L1 expression in male breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-23-05.

The Resolution of Helicobacter suis-associated Gastric Lesions after Eradication Therapy

A reddish depressed lesion was found in the corpus of the stomach of a 56-year-old man. Gastric biopsy showed no findings of mucosa-associated lymphoid tissue lymphoma, including lympho-epithelial lesions. A urea breath test, stool antigen test and serum IgG antibody to Helicobacter pylori test were negative. Magnifying endoscopy using narrow-band-imaging showed no malignant structures. Gastric biopsy specimens were subjected to immunohistochemistry and a polymerase chain reaction, which identified Helicobacter suis infection. Triple therapy with esomeprazole, metronidazole, and amoxicillin was administered for 10 days. Three months later, endoscopy showed the significant improvement of the lesion. H. suis infection should be considered in chronic gastritis patients without H. pylori infection.

Anthropometric and Skeletal Parameters Predict 2-Strand Semitendinosus Tendon Size in Double-Bundle Anterior Cruciate Ligament Reconstruction

Background:

Few studies have examined whether skeletal parameters predict hamstring graft size during anterior cruciate ligament reconstruction (ACLR).

Purpose/Hypothesis:

The purpose of this study was to examine whether preoperative anthropometric and radiographic skeletal parameters could predict hamstring graft size during ACLR. We hypothesized that both anthropometric and skeletal parameters can be used to predict graft size in our double-bundle procedure and that the use of skeletal parameters will improve the accuracy of graft size prediction.

Study Design:

Cross-sectional study; Level of evidence, 3.

Methods:

A total of 200 patients were recruited and underwent double-bundle ACLR using a semitendinosus (ST) graft. The harvested tendon was measured to determine graft length (GL) and then split at its midpoint. The graft diameters of the anteromedial (GD_AM) and posterolateral bundles (GD_PL) were measured at the femoral aspect of the 2-stranded graft. The mean diameters of both bundles were included in the analysis. On the coronal radiograph, femorotibial angle (FTA), femoral interepicondylar distance (IED), and tibial plateau width (coronal tibial width [CTW]) were measured. Blumensaat line length (BLL) and the lateral tibial width (LTW) were measured on the lateral radiograph. A linear regression analysis was conducted using graft size as the dependent variable and age, sex, height, weight, Tegner activity score, and skeletal parameters as the independent variables.

Results:

Mean GL was 258.9 ± 21.9 mm, GD_AM was 5.9 ± 0.5 mm, and GD_PL was 5.7 ± 0.6 mm. Single regression analysis showed that GL was significantly predicted by sex, height, weight, Tegner activity score, IED, CTW, BLL, and LTW (R² range, 0.033-0.342). GD was predicted by sex, height, weight, IED, CTW, BLL, and LTW (R² range, 0.094-0.207). Stepwise multiple linear regression analysis significantly confirmed sex, height, and age as the variables to comprehensively predict GL (R² = 0.384). With regard to GD, stepwise multiple regression confirmed height and IED as significant variables (R² = 0.224).

Conclusion:

Both preoperative anthropometric and radiographic parameters on plain radiographs were able to predict harvested GL and 2-strand GD. Multivariate regression slightly improved the prediction of graft dimensions compared with univariate regression.

Low prevalence of knee chondrocalcinosis and its catabolic association with serum matrix metalloproteinase 3: A rural Japanese population study

AIM

This study aimed to elucidate the prevalence of radiographic knee chondrocalcinosis (CC) and to clarify whether CC is correlated with self-reported knee symptoms and a serum catabolic biomarker.

METHODS

A total of 1278 volunteers participated. Plain radiographs of both knees were obtained. Identification of a linear calcification in the knee joint space was defined as CC. Patients with a Kellgren-Lawrence grade of 2 or more were considered to have knee osteoarthritis (OA). Symptoms were evaluated using the Knee injury and Osteoarthritis Outcome Score (KOOS) Pain scale, and serum matrix metalloproteinase-3 (MMP-3) concentration was determined. Multiple regression analysis was conducted to determine whether CC was correlated with OA, the KOOS Pain scale and MMP-3 concentration.

RESULTS

Twenty-eight subjects were found to have CC (2.2%), and 389 had OA (30.4%). CC was correlated with OA (odds ratio: 5.797; P = 0.006). Additionally, CC was correlated with MMP-3 concentration (B = 11.415, β = 0.059, P = 0.014), but not with KOOS Pain scale.

CONCLUSIONS

The prevalence of CC was low in the Japanese population evaluated in this study. While CC was not correlated with self-reported knee symptoms, it was positively correlated with serum MMP-3 concentration.

Serum pentosidine concentration is associated with radiographic severity of lumbar spondylosis in a general Japanese population

The aim of this study was to investigate the relationship between the radiographic severity of lumbar spondylosis (LS) and serum bone metabolic markers. A total of 681 individuals volunteered for this study (269 men, 412 women; age: 54.9 ± 14.3; body mass index [BMI]: 23.1 ± 3.3 kg/m²). Lateral lumbar radiographs were evaluated in each intervertebral section (L1/2 to L5/S1) using the Kellgren-Lawrence grade (KL). If at least one intervertebral section was graded as KL 2 or greater, the participants were considered to have LS. The summation of each section of intervertebral section was used as the radiographic severity value of LS. In addition, bone status was evaluated with an osteo-sono assessment index (OSI) at the calcaneus. Serum bone alkaline phosphatase (μg/mL), N-telopeptide of type I collagen (nMBCE/L), and pentosidine (pmol/mL) concentrations were examined and used as the bone metabolism index. Stepwise multiple linear regression analysis was conducted with the radiographic severity value of LS as the dependent variable and age, sex, BMI, OSI, and the value of serum bone metabolic markers as the independent variables. The total number of LS participants was 470 (69.0 %); the frequency of LS was higher in men (n = 198) than in women (n = 272; P = 0.036, χ ² test). The mean severity value of LS was 7.1 ± 4.4, and the mean value of pentosidine was 120.7 ± 54.8 pmol/mL. On multiple regression analysis, age (B = 0.190, β = 0.611), sex (men = 1, women = 2; B = -0.900, β = -0.099), BMI (B = 0.185, β = 0.136), and pentosidine (B = 0.009, β = 0.115) were significantly correlated with the severity of LS. Serum pentosidine concentration was positively correlated with the radiographic severity of LS in this cross-sectional study.